Microbiological and serological diagnostic tests for Helicobacter pylori

PDF document for free

1. PDF document for free

76506_754_1_175.pdf

Microbiological and serological diagnostic

test s fo r Helicobacter pylori: a n overvie w Your i Glupczynsk i

Service

de Biologie Clinique, Cliniques Universitaires UCL de Mont-Godinne, Yvoir, Belgium

Differen

t invasiv e an d non-invasiv e diagnosti c test s ar e availabl e fo r th e diagnosi s o f H. pylori i n th e individua l patient . I n practice , endoscopi c test s ar e bes t fo r a primar y diagnosi s o f H. pylori infectio n becaus e endoscop y allow s assessmen t o f treatmen t indications . Th e ne w rapi d ureas e test s ma y hel p th e clinicia n i n treatmen t decision-making . Cultur e i s currentl y no t recommende d fo r routin e evaluation , bu t i t i s becomin g increasingl y importan t i n certai n population s wit h highe r prevalenc e o f dru g resistance , sinc e i t allow s testin g fo r susceptibilit y t o antibiotics . Serologica l testin g ha s bee n recommende d fo r initial pre-endoscop y o r pre-treatmen t screenin g i n dyspepti c patients . However , severa l curren t 'in-office ' test s appea r insufficientl y accurat e o r woul d nee d further validatio n befor e bein g recommende d fo r us e i n clinica l managemen t strategie s a t a primar y car e level . Th e ure a breat h test s ar e bes t suite d t o confir m eradicatio n earl y afte r treatment , whil e laborator y serolog y test s ar e o f limite d use , sinc e 6 month s ar e require d befor e a resul t ca n b e obtained . Th e serologica l offic e test s canno t b e use d fo r post-treatmen t assessmen t o f H. pylori status .

Correspondence

to: Dr Y.

Glupczynski,

Service de

Biologie

Clinique,

Cliniques

Universitaires UCL de Mont-Godinne, 1 Av. Dr G . Therasse,

B-5530

Yvoir, BelgiumThe recognition that H. pylori plays a pivotal role in the pathogenesis of severa l gastroduodena l pathologie s make s it s diagnosi s necessar y i n man y differen t circumstances . Sinc e th e origina l descriptio n o f th e organis m b y

Marshal

l an d Warre n i n 1982
1 , numerou s reliabl e invasiv e an d non - invasiv e diagnosti c test s hav e bee n developed . Eac h ha s advantage s an d disadvantage s whic h wil l mak e i t mor e o r les s appropriat e dependin g o n th e clinica l situation . Th e invasiv e biopsy-base d test s whic h includ e rapid ureas e test , histolog y an d cultur e ar e importan t i n th e assessmen t o f H. pylori statu s pre-treatment , a s endoscop y allow s assessmen t o f treatmen t indication s suc h a s ulce r disease 2 . Th e non-invasiv e test s obviat e th e nee d fo r endoscop y an d compris e serolog y an d th e ure a breat h test , usin g eithe r 13 C o r 14 C . I n vie w o f th e patch y distributio n o f H. pylori, al l biopsy-base d test s ma y theoreticall y fai l t o diagnos e th e infection . Th e inheren t ris k o f samplin g erro r can , however , b e virtuall y eliminate d b y obtainin g severa l biops y sample s fro m th e gastri c corpu s a s wel l a s th e fro m th e antrum 3 . I n contras t t o

British

Medical Bulletin 1998;5
4 (No . 1) : 175-18

6C The British Council 1998Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

biopsy-base d methods , non-invasiv e test s asses s th e globa l presenc e o f H. pylori i n th e stomac h eve n whe n th e bacteri a ar e irregularl y dis - tribute d o n th e gastri c mucosa . No n endoscopi c tests , particularl y serology , ar e cheape r an d mor e convenient , an d thu s shoul d b e preferre d i n situation s wher e th e additiona l informatio n yielde d b y a n endoscop y i s not needed . Th e ai m o f thi s pape r i s t o revie w curren t microbiologica l diagnosti c modalitie s fo r H. pylori an d t o emphasis e thei r preferentia l indication s takin g int o accoun t th e particula r setting s i n whic h a diagnosi s i s t o b e mad e (pre-treatmen t screenin g o r follow-u p afte r treatment) . I t als o give s a brie f overvie w o f th e deficiencie s o f curren t test s an d o f expecte d futur e developments .

Invasiv

e test s

Urease

tests Th e ureas e test s provid e a simple , rapi d an d cost-effectiv e metho d fo r th e detectio n o f H. pylori. However , th e practica l valu e o f thes e test s depend s no t onl y o n thei r sensitivit y an d specificity , bu t als o o n thei r speed , henc e makin g the m a practica l too l fo r th e endoscopis t i n decision-makin g a s t o whethe r o r no t therap y shoul d b e prescribed . Amon g th e variou s rapi d ureas e test s whic h hav e bee n describe d i n th e literature , severa l wer e foun d t o lac k sensitivit y whe n earl y readin g wa s performe d (withi n 1 h) .

Differen

t method s hav e bee n propose d t o speed-u p colou r change , suc h a s pre-heatin g o f th e ki t o r incubatio n at37° C o r higher . Yousf i et al 4 foun d tha t th e diagnosti c yiel d fo r detectin g H. pylori b y th e rapid ureas e tes t wa s no t adversel y affecte d b y th e siz e o f th e biops y forceps , whil e Lain e et al 5 showe d tha t increasin g th e amoun t o f tissu e i n CLO-test s di d significantl y haste n th e developmen t o f positiv e tests . I n anothe r study , Wo o et al 6 investigate d th e bes t gastri c sit e fo r obtainin g a positiv e rapi d ureas e test . The y foun d tha t biopsie s fro m th e gastri c angulu s ha d th e highes t sensitivit y fo r th e detectio n o f H. pylori a s compare d t o th e prepylori c an d corpu s sites . Interestingly , th e media n tim e t o positivit y was simila r wit h th e angulu s an d prepylori c sites , but i t wa s significantl y shorte r tha n fo r th e biopsie s fro m th e corpu s (6 0 versu s 18 0 min , respectively) . Malfertheine r et aV evaluate d com - parativel y tw o commercia l rapi d ureas e tests , th e HUT-tes t an d th e

CLO-test

. Bot h test s displaye d comparabl e sensitivitie s an d specificitie s (93 % an d 100
% fo r th e HUT-test ; 88
% an d 100
% fo r th e CLO-test ) despit e th e fac t tha t tw o biops y sample s (antru m an d dista l gastri c body ) ha d bee n obtaine d fo r th e HUT-tes t whil e onl y on e antra l specime n wa s 17 6 British Medical Bulletin 1998;5
4 (No . 1 )Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Practical diagnosis of H. pylori

sample d i n th e CLO-test . The y conclude d tha t th e samplin g o f on e additiona l gastri c biops y di d no t improv e significantl y th e diagnosti c efficac y i n untreate d patients , but tha t i t coul d b e require d followin g treatmen t wit h proto n pum p inhibitors , sinc e i n thi s case , H. pylori i s mor e likel y t o b e foun d onl y i n th e bod y mucos a an d not i n th e antrum . I n recen t years , newe r generation s o f commercia l test s hav e bee n introduce d o n th e market . On e o f suc h stri p test , th e Pyloritek ® i s designe d t o giv e a 1 h reading , withou t requirin g specia l incubatio n temperature s whil e allowin g severa l biopsie s t o b e teste d a t th e sam e time .

Severa

l studie s hav e show n tha t th e Pyloritek ® provide s a sensitivit y (90-99% ) an d a specificit y (95-100% ) a t leas t equivalen t t o thos e achieve d b y th e CLO-tes t o r othe r agar-base d test s afte r 12-2 4 h 8 " 10 .

However

, th e averag e tim e require d t o achiev e a positiv e resul t wa s onl y 20-3 0 mi n wit h th e Pyloritek ® versu s 120-15
0 mi n wit h th e agar-base d tests , an d th e forme r tes t wa s foun d t o b e significantl y mor e sensitiv e a t 1 h tha n al l othe r ureas e test s withou t compromisin g specificity .

Culture

Cultur

e undoubtedl y constitute s th e mos t specifi c wa y t o establis h th e diagnosi s o f H. pylori infection , bu t it s sensitivit y ha s bee n foun d t o var y greatl y betwee n centres . Th e difference s i n performance s observe d betwee n laboratorie s probabl y reflec t difference s i n expertis e wit h cultur e techniques .

Althoug

h i t i s stil l generall y considere d a s a tediou s procedure , cultur e ca n nowaday s b e performe d wit h minima l difficultie s i n almos t ever y genera l hospita l wit h a standar d microbiolog y laboratory . Cultur e is , however , no t necessar y fo r th e routin e diagnosi s o f H. pylori infectio n becaus e othe r invasiv e test s wil l detec t th e organism s i n mos t patients . On e o f th e majo r advantage s o f cultur e i s tha t i t allow s sensitivit y testin g o f H. pylori t o th e agent s use d i n th e treatment . Thi s i s particularl y importan t fo r th e clinicia n wh o mus t manag e patient s i n who m antibiotic - resistan t isolate s ar e suspecte d (e.g. i n area s wit h hig h rate s o f resistanc e t o antimicrobia l drugs ) o r thos e wh o hav e faile d wit h antimicrobia l dru g regimen s know n t o selec t fo r th e developmen t o f resistance 3 .

Althoug

h th e ris k o f samplin g erro r i s probabl y lowe r tha n generall y supposed , i t i s advisabl e t o tak e tw o biops y sample s fo r culture . Cultur e fro m eithe r th e antru m o r th e corpu s ha s a n excellen t diagnosti c yiel d i n untreate d patients , bu t samplin g o f bot h gastri c site s i s recommende d followin g treatmen t i n orde r t o optimiz e th e detectio n o f H. pylori 11 ' 12 .

Anothe

r facto r tha t ma y influenc e th e succes s rat e o f cultur e involve s th e transpor t condition s fro m th e endoscop y roo m t o th e laboratory .

Severa

l liqui d o r semi-soli d transpor t medi a hav e bee n recommended , bu t

British

Medial Bulletin 1998,5
4 (No . 1 ) 17

7Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

i t i s no t clea r whethe r a specifi c mediu m compositio n i s superio r fo r thi s purpose . Roosendaa l et at 13 di d no t fin d qualitativ e difference s betwee n fiv e differen t media , althoug h quantitativ e dat a wer e no t shown . I n severa l o f th e abov e mentione d studies 11 - 13 , th e recover y rate s o f H. pylori fro m gastri c biopsie s wer e no t adversel y affecte d b y a dela y o f cultur e u p t o 2 4 h whe n transpor t medi a wer e hel d a t roo m temperature . Fo r trans - portatio n o r storag e longe r tha n 2 4 h a lowe r temperatur e might , however , b e a n importan t facto r fo r survival . Ha n et at 14 foun d a 100
% cultur e recover y fro m 1 6 gastri c biopsie s o f H. pylori-positive patient s store d i n a cystein e + 2 % glycero l transpor t mediu m store d a t -20° C fo r 4 week s versu s onl y 57
% afte r 1 2 week s storage . Recover y figure s whe n storag e wa s a t +4° C wer e 81
% an d 19% .

Differen

t cultur e medi a hav e bee n propose d fo r growt h o f H. pylori. I n on e recen t study , i n whic h severa l conventiona l medi a wer e compared , brai n hear t infusio n (BHI ) aga r supplemente d wit h 7 % lyse d hors e bloo d yielde d th e highes t isolatio n rat e an d th e highes t numbe r o f H. pylori colonies 15 . I t i s probable , however , tha t th e us e o f freshl y prepare d medi a rathe r tha n th e mediu m itsel f accounte d fo r th e succes s o f BH I aga r i n thi s study . T o suppres s th e growt h o f endogenou s o r exogenou s contaminatin g bacteria , selectiv e medi a ar e require d t o improv e th e isolatio n o f H. pylori fro m biops y samples 3 ' 1112
. Severa l selectiv e cultur e medi a hav e bee n develope d fo r optima l isolatio n o f H. pylori. I n a larg e comparativ e study , BH I aga r supplemente d wit h 10 % shee p blood , polymyxi n B , vanco - mycin , trimethopri m an d amphoterici n B yielde d th e highes t isolatio n rat e (99%) an d wa s foun d t o b e superio r t o Skirrow' s selectiv e mediu m (71 % isolatio n rate ) fo r primar y isolatio n o f H. pylori fro m gastri c biops y specimens 16 . However , combinatio n o f a t leas t on e selectiv e an d on e non - selectiv e cultur e mediu m i s generall y advocated , sinc e n o singl e cultur e mediu m allow s a 100
% recover y rat e o f H. pylori an d becaus e cultur e contaminatio n occur s i n abou t 25
% o f th e cases 11 - 12 . Th e patient' s oropharyngea l flor a ca n als o markedl y reduc e th e isolatio n rate s an d th e colon y number s o f H. pylori. I n on e study 17 , rinsin g o f th e biopsie s i n steril e salin e wa s show n t o improv e th e recover y o f H. pylori i n nearl y 40
% o f th e culture s processed .

Finally

, failur e t o detec t H. pylori b y cultur e ma y b e du e t o insufficien t duratio n o f incubation . Incubatio n period s o f u p t o 1 0 day s ar e usuall y recommende d i n orde r t o optimis e th e cultur e isolatio n rates , especiall y i n a post-treatmen t setting 11 ' 12 .

Polymerase

chain reaction (PCR) PC R i s regarde d a s th e mos t sensitiv e techniqu e fo r th e detectio n o f micro-organisms . Th e detectio n o f H. pylori i n gastri c biops y sample s o r 17 8 British Medical Bulletin 1998;5
4 (No . 1 )Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Practical diagnosis of H. pylori

i n gastri c juic e aspirate s b y PC R ha s bee n evaluate d b y severa l investigator s an d wa s foun d t o perfor m well , wit h sensitivit y an d specificit y usuall y ove r 95%
a s compare d t o othe r invasiv e methods 18 " 21
. Give n th e usua l hig h sensitivit y o f PCR , thi s tes t ca n b e particularl y usefu l fo r th e post-treatmen t diagnosi s o f H. pylori, whe n th e bacteria l loa d ma y b e ver y low . However , i n severa l comparativ e studies , th e PC R tes t faile d t o detec t significantl y mor e treatmen t failure s tha n cultur e o r a combinatio n o f othe r conventiona l methods 3 - 22
. Owin g t o it s hig h sensitivity , PC R unfortunatel y carrie s a ris k o f fals e positiv e result s whic h ma y resul t eithe r fro m residua l H. pylori DN A o n th e fiberopti c endoscope s followin g inadequat e cleanin g an d disinfectio n o r fro m cross-contaminatio n durin g processin g o f specimen s i n th e laboratory 23
. A t present , PC R i s stil l technicall y demandin g an d no t generall y availabl e a s a routin e diagnosti c tool . Recently , however , methodo - logica l protocol s hav e bee n simplifie d an d improve d b y usin g hybrid - izatio n an d colorimetr y t o detec t th e amplificatio n products 24
. I t ca n b e anticipate d tha t PC R wil l b e use d mor e readil y i n routin e clinica l setting s onc e bein g full y automate d an d whe n commercia l kit s becom e available . I t i s als o likel y that , i n th e nea r future , PC R o r closel y relate d molecula r amplificatio n technique s wil l b e use d i n rapid tes t format s t o detec t antimicrobia l resistanc e (i.e. resistanc e t o macrolides ) t o H. pylori an d possibl y als o i n faece s t o contro l eradication .

Non-invasiv

e test s

Serology

H. pylori infectio n provoke s bot h loca l an d systemi c antibod y responses . Th e systemi c respons e typicall y comprise s a transien t ris e i n IgM , followe d b y a ris e i n specifi c Ig A an d Ig G maintaine d throughou t infection . A larg e numbe r o f kit s whic h detec t thes e antibodie s b y enzyme-linke d immunosorben t assa y (ELISA ) o r late x agglutinatio n hav e bee n develope d an d mos t clinica l laboratorie s ar e experience d i n performin g serologica l tests . Suc h test s mos t commonl y us e serum , althoug h detectio n o f Ig G i n urin e ha s als o prove d accurate 25
. Severa l commercia l o r in-hous e test s hav e bee n adapte d fo r us e o n saliva , but th e detectio n o f salivar y Ig A o r Ig G antibodie s ha s prove d overal l les s sensitiv e tha n serum-base d tests 26
- 27
. Th e performanc e o f differen t laborator y serologica l test s ha s bee n foun d t o var y appreciably . I n a larg e meta-analysis , severa l commercia l ELIS A kit s appeare d t o perfor m wel l wit h sensitivit y an d specificit y value s averagin g 90-95
% an d 80-90%
, respectivel y (Tabl e 1) . Th e

British

Medical Bulletin 1998;5
4 (No . 1 ) 17

9Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

Tabl e 1 Comparativ e performanc e value s o f variou s H. Tes t Coba s Core *

Hellco-G

*

Malakit

*

GAPHgG

* Pylor i Stat * HM-CA P

Premie

r H. pylori

Pyloriset

* EI A G

Pyloriset

* EI A G *Brand name Roch e

Porton-Cambridg

e Biola b

Bio-Ra

d

Bio-Whlttake

r

Enteri

c Product s Os i Orio n (old ) Orio n (new )No. patient s 153
8 101
3 30
8 107
7 96
3 57
5 20 9 38
1 25
6No. scrie s 6 1 2 3 9 8 2 3 3

2pylori ELISA commercial kits

Sensitivit

y (% ) (average ) 93-9
9 (95 ) 71-9
6 (82 ) 87-9
6 (90 )

77-100(90

) 90-9
9 (96 ) 95-9
8 (97 ) 87-9
3 (89 ) 76-9
6 (91 ) 93-10
0 (97 )Specificity (%) (average ) 77-9
7 (88 ) 45-9
0 (70 ) 79-9
6 (86 ) 26-9
1 (63 ) 70-9
8 (90 ) 92-9
8 (93 ) 81-9
6 (88 ) 84-9
6 (86 ) 79-8
5 (83 ) - *Th e ne w versio n wa s introduce d i n 1995
. lowe r specificit y o f serologica l test s observe d i n certai n studie s ma y hav e largel y bee n explaine d b y th e inclusio n o f patient s previousl y treate d fo r H. pylori infectio n o r havin g receive d antibiotic s fo r th e treatmen t o f variou s intercurren t infections 21
. A combinatio n o f reliabl e referenc e method s need s t o b e applie d fo r evaluatio n o f test s an d difference s i n th e gol d standar d use d ma y als o hav e accounte d fo r som e o f th e difference s tha t hav e bee n observe d betwee n studies . Furthermore , difference s i n tes t accurac y ca n b e explaine d b y th e us e o f variou s antige n preparation s o r b y difference s i n infectin g strain s tha t resul t i n differen t immun e responses . Thi s ha s le d t o th e genera l recommendatio n tha t an y serologica l tes t fo r H. pylori shoul d b e validate d an d standardise d locall y befor e use . I n man y instances , thi s wil l impl y th e adjustmen t o f th e cut-of f value s recommende d b y th e manufacturer .

Numerou

s studie s hav e evaluate d th e performanc e o f a wid e rang e o f commercia l tests 2 ** 31
. I n mos t o f thes e reports , th e differen t test s per - forme d equall y well . Feldma n et aP l recentl y reporte d a multi-laborator y compariso n o f eigh t commerciall y availabl e H. pylori serolog y kits . A s show n i n Tabl e 2 , som e o f th e kit s produce d excellen t results . A numbe r o f rapi d serologica l offic e test s hav e recentl y bee n develope d fo r th e serodiagnosi s o f H. pylori infection 32
"* 0 . The y ar e base d o n a solid - phas e ELISA 32
- 3 3 o r o n late x agglutination 34
. On e majo r advantag e o f thes e test s ove r laborator y tests , i s tha t the y ca n b e applie d ver y easil y i n th e offic e o n whol e bloo d obtaine d b y fingerprick . Result s ar e availabl e o n sit e withi n 5-1 0 min , usuall y b y a simpl e colou r change , an d ther e i s n o nee d fo r an y specifi c equipment . I n a larg e meta-analysi s o f studie s publishe d i n th e literature , th e rapi d offic e test s overal l appeare d t o b e les s accurat e tha n th e laborator y tests , wit h sensitivit y an d specificit y value s averagin g 80-85
% an d 75-80%
, respectivel y (Tabl e 3) . I n som e studie s comparin g th e rapi d test s wit h onl y on e standard , th e sensitivit y result s wer e usuall y substantiall y better 32
. I n othe r reports 39
, th e 'office ' test s showe d poo r specificit y i n certai n populatio n ag e group s 18

0British Medical Bulletin 1998,54 (No. 1)Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Practical diagnosis of H. pylori

Tabl e 2 Sensitivit y an d specificit y o f eigh t commercia l kit s teste d i n 1 7 laboratorie s o n identica l seru m sample s fro m 5 9 patient s (Optica l densit y value s i n th e gre y zon e wer e considere d negative ) Tes t Amra d Biola b

Bio-Ra

d Orio n Porto n Radi m Roch e

Whittake

rNo of laboratorie s 1 7 1 5 1 7 1 7 1 7 1 3 1 7 1

6Mean sensitivity

(SD ) 89.
4 (7.7 ) 79.
9 (9.1 ) 94.
9 (6.8 ) 95.
8 (3.9 ) 92.
3 (6.1 )

81.6(7.0

)

99.3(1.3

) 92.
9 (4.9 )Mean specificity (SD ) 93.
9 (9.7 ) 98.
6 (2.6 )

91.3(13.2

) 95.
5 (4.8 ) 87.
1 (12.6 )

90.7(17.6

) 86.
5 (5.2 )

89.4(11.1

) S D = standar d deviation : Adapte d from Feldma n et aP\ Tabl e 3 Performanc e value s o f variou s commercia l H. pylori rapi d test s ('office-base d tests' ) Tes t

Pylorise

t Dry *

Pylorise

t latex * Late x

FlexSure

*

Helisal

*

Immunocard

* Quic k Vue * CLOse rBrand nam e Orio n Diagnostic a Orio n Diagnostic a Oxoi d

SmithKlin

e Diagnostic s

Cortec

s

Meridia

n Diagnostic s Qulde l

Medica

l Instrument sNo patient s 34
8 93
2 20 2 116
9 78
8 7 8 72
7 8 6No serie s 3 8 1 5 5 1 3

1Sensitivity (%)

(average ) 80-9
7 (89 ) 60-9
2 (75 ) 8 6 74-9
5 (86 ) 82-9
2 (84 ) 9 2 82-9
9 (91 ) 9

5Specificity (S)

(average ) 77-8
5 (81 ) 50-7
6 (63 ) 7 5 69-8
9 (81 ) 56-9
1 (73 ) 9 8 52-9
2 (79 ) 7 2 (patient s ove r 4 5 year s o f age ) a s wel l a s i n som e ethni c group s (e.g. Sout h

Asians

) whil e the y performe d bette r i n som e othe r populatio n subgroup s (e.g. patient s les s tha n 4 5 year s o f ag e an d Europea n natives) . Moreover , problem s o f poo r readabilit y o f result s an d inter-observe r variation s i n interpretatio n o f result s wer e reporte d i n a notabl e proportio n o f case s (u p t o 10 % o f al l results ) i n som e studies 38
- 39
, whic h ma y limi t th e valu e o f certai n kits . Abov e all , i t i s importan t t o stres s tha t mos t reporte d evaluation s o f th e rapid office-base d serologica l test s hav e bee n undertake n i n a secondar y car e settin g an d i n patient s referre d fo r endoscopy . Ther e are , a t present , fe w report s o f th e evaluatio n o f thes e test s i n th e environmen t fo r whic h the y wer e designe d an d i t wil l b e particularl y importan t t o examin e th e result s obtaine d b y genera l practitioner s wh o wil l b e th e clinician s mos t likel y t o us e suc h screenin g devices . I n addition , i t wil l als o b e ver y importan t t o evaluat e th e short - an d long-ter m impac t tha t th e offic e serologica l test s ma y hav e o n th e clinica l managemen t o f patient s i n th e primar y car e setting .

British

Medical Bulletin 1998;5
4 (No . 1 )181Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

Immunoblo

t technique s als o sho w promise . Heterogeneit y ha s bee n observe d i n th e immun e response , bu t th e predictiv e valu e o f a give n ban d o r patter n fo r a specifi c patholog y i s stil l uncertai n an d it s useful - nes s i n patien t follow-u p ha s ye t t o b e determined 40
. However , som e studie s hav e show n tha t th e us e o f recombinan t antige n fo r cagA ma y b e valuabl e fo r predictin g th e presenc e o f pepti c ulce r diseas e i n a patient 41
. A s wit h th e ne w serologica l tests , furthe r wor k i s neede d t o establis h th e utilit y o f serologica l testin g fo r selectiv e pathogeni c strain s (e.g. cag A serology) , bu t i t ma y b e usefu l i n strategie s aime d a t narrowin g th e grou p o f patient s fo r who m H. pylori treatmen t shoul d b e considered . Urea breath tests Th e [ 13

C]-ure

a breat h tes t i s highl y sensitiv e an d specifi c fo r th e detectio n o f H. pylori infection . I n contras t t o serolog y whic h canno t alway s distinguis h betwee n pas t an d presen t infection , th e ure a breat h tes t i s a measur e o f curren t H. pylori infection . I t i s particularl y wel l suite d a s a follow-u p tes t i n th e earl y post-treatmen t perio d (4- 6 week s afte r en d o f therapy ) sinc e i t ha s a goo d predictiv e valu e fo r th e eradicatio n o f th e bacterium . I t i s a non-invasive , globa l tes t whic h i s eas y t o perfor m an d i s independen t o f transpor t condition s o r th e experienc e o f th e tester . Despit e thes e advantages , however , thi s tes t i s not ye t widel y availabl e an d i t i s stil l no t approve d i n man y Europea n countries . A comprehensiv e revie w o f th e ure a breat h test s i s presente d elsewher e i n thi s issue . Ke y point s fo r clinica l practic e • Wit h th e continuou s improvemen t o f diagnosti c techniques , th e availabilit y o f ne w diagnosti c test s an d th e efficac y o f moder n treatmen t regimen s i t i s t o b e expecte d tha t th e deman d fo r H. pylori testin g an d treatmen t initiate d a t a primar y car e leve l wil l als o increase . Severa l large-scal e comparativ e studie s hav e show n tha t invasiv e an d non - invasiv e test s performe d equall y well , wit h a sensitivit y an d specificity , i n th e rang e o f 90%
21>43
. I n practice , th e choic e o f a particula r tes t shoul d b e influence d b y loca l availabilit y an d expertise , a s wel l a s b y clinica l circumstances . • Th e hig h ureas e activit y o f H. pylori ca n b e use d a s a screenin g marke r o f infectio n i n patient s wh o presen t t o endoscop y wit h uppe r gastrointestina l symptoms . Th e newe r rapid ureas e stri p tests , whic h hav e bee n considerabl y improve d i n compariso n t o th e initia l ureas e 18 2 British Medical Bulletin 1998;5
4 (No . 1 )Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Practical diagnosis of H. pylori

tests , ma y certainl y hel p th e endoscopis t i n decision-makin g a s t o whethe r o r no t therap y shoul d b e prescribed . Du e t o thei r lo w cost , thes e test s ar e th e endoscopi c test s o f choic e fo r initia l evaluation .

However

, the y shoul d b e use d i n additio n t o othe r invasiv e o r non - invasiv e test s (e.g. serology ) a s som e infecte d patient s ma y stil l b e misse d o n a n initia l screening . • Cultur e canno t b e recommende d fo r routin e evaluatio n o f H. pylori becaus e o f th e restricte d availabilit y o f goo d laborator y facilitie s an d th e man y potentia l error s involve d leadin g t o false-negativ e results .

However

, i t shoul d b e considere d whe n treatin g th e infectio n wit h a regime n tha t contain s drug s t o whic h H. pylori i s possibl y resistant .

Likewise

, cultur e shoul d b e favoure d afte r documente d treatmen t failur e o r i n patient s fro m a geographi c are a o r o f a n ethni c origi n wit h highe r likelihoo d o f antimicrobia l dru g resistance . PC R i s presentl y no t indicate d fo r us e i n th e routin e clinica l setting . However , th e rapid technologica l improvement s an d th e availabilit y o f commercia l kit s ma y rende r thi s techniqu e mor e readil y availabl e i n th e nea r future . • Th e ure a breat h test s ar e ver y accurat e fo r assessin g th e H. pylori statu s post-treatment . However , the y ar e stil l no t ye t widel y available .

Serolog

y ha s onl y limite d indicatio n fo r th e follow-u p afte r treatment .

Antibod

y titre s t o H. pylori var y markedl y betwee n infecte d individual s and , followin g successfu l treatment , tak e on e o r mor e year s t o retur n t o th e uninfecte d range , th e exac t tim e bein g dependen t o n th e hos t respons e an d o n th e tes t used . Rapi d offic e test s ar e no t quantitativ e an d ar e no t suitabl e fo r us e i n treatmen t follow-up . Whe n usin g quantitativ e ELISA , a 50
% decreas e i n Ig G titre s a t 6 month s ca n accuratel y predic t treatmen t success 43
. However , matche d pre - an d 6 mont h post-treatmen t seru m sample s ar e needed , an d preferabl y shoul d b e ru n togethe r t o avoi d inter-batc h variation . Thi s seem s difficul t t o appl y routinel y becaus e collectin g an d storin g pre-treatmen t specimen s ma y b e problemati c i n clinica l practic e an d als o becaus e 6 month s i s a lon g tim e t o wai t fo r results . • O n th e othe r hand , serologica l H. pylori screenin g appear s particularl y attractiv e a s a pre-endoscop y o r a s a pre-treatmen t screenin g i n youn g dyspepti c patient s (age d les s tha n 4 5 years ) withou t alar m symptoms . Suc h recommendation s ar e supporte d b y a recen t

Europea

n consensu s repor t o n curren t concept s o n th e managemen t o f H. pylori infection 44
. However , th e feasibilit y o f algorithm s base d o n serologica l H. pylori statu s an d ag e wil l greatl y depen d o n th e incidenc e o f specifi c gastroduodena l pathologie s i n differen t population s a s wel l a s o n th e performance s o f th e screenin g tests . Screenin g test s wit h optima l

British

Medial Bulletin 1998;5
4 (No . 1 ) 18

3Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

sensitivit y woul d absolutel y b e require d i f use d t o selec t suitabl e group s o f patient s fo r endoscop y withou t missin g significan t disease . • Conversely , test s yieldin g a hig h specificit y woul d b e necessar y i n orde r t o avoi d givin g unnecessar y eradicatio n therap y t o non-infecte d patients . Som e o f th e ne w offic e serologica l test s currentl y availabl e ma y not appea r sufficientl y accurat e t o fulfi l thes e requirements . Furthe r researc h i s clearl y neede d i n orde r t o delineat e th e plac e tha t rapi d H. pylori serologica l test s ma y hav e i n a primar y car e environment . Th e cost-effectivenes s an d clinica l consequence s o f differen t serology-base d strategie s shoul d als o b e establishe d an d ma y b e foun d t o diffe r betwee n countrie s wit h differen t healthcar e system s an d differen t economi c constraints .

References

1 Marshal l BJ , Warre n JR . Unidentifie d curve d bacill i i n th e stomac h o f patient s wit h gastriti s an d pepti c ulceration . Lancet 1994
; i : 1311-
5 2 NI H Consensu s Developmen t Panel . Helicobacter pylon i n pepti c ulce r disease . JAMA 1994
; 272
: 65-
9 3 va n Zwe t AA , Thij s JC , Roosendaa l R , Kuiper s EJ , Pen a S , d e Graaf f J . Practica l diagnosi s o f

Helicobacter

pylori infection . Eur J Gastrocnterol Hepatol 1996
; 8 : 501-
7 4 Yousf i MM , El-Zimait y HM , Col e RA , Gent a RM , Graha m DY . Detectio n o f Helicobacter pylon b y rapi d ureas e tests : i s biops y siz e a critica l variable ? Gastromtest Endosc 1996
; 43
: 222 -
4 5 Lain e L , Chu n D , Stei n C , El-Beblaw i I , Sharm a V , Chandrasom a P . Th e influenc e o f siz e o r numbe r o f biopsie s o n rapi d ureas e tes t results : a prospectiv e evaluation . Gastrointest Endosc 1996
; 43
: 49-5
3 6 Wo o JS , El-Zimait y HMT , Gent a RM , Yousf i MM , Graha m DY . Th e bes t gastri c sit e fo r obtainin g a positiv e rapi d ureas e test . Helicobacter 1996
; 4 : 256-
9 7 Malfertheine r P , Dominguez-Muno z J , Heckenmulle r H , Neubran d M , Fische r HP , Sauerbruc h T . Modifie d rapi d ureas e tes t fo r detectio n o f Helicobacter pylori infection . Eur J Gastroenterol

Hepatol

1996
; 8 : 53-
6 8 Lain e L , Lewi n D , Naritok u W , Estrad a R , Cohe n H . Prospectiv e compariso n o f commerciall y availabl e rapi d ureas e test s fo r th e diagnosi s o f Helicobacter pylori. Gastrointest Endosc 1996
; 44
: 523-
6 9 Puet z T , Vaki l N , Phadin s S , Dun n B , Robinso n J . Th e Pylorite k an d th e CL O test : accurac y an d incrementa l cos t analysis . Am ] Gastroenterol 1997
; 92
: 254 -
7 1 0 Yousf i MM , El-Zimait y HM , Gent a RM , Graha m DY . Evaluatio n o f a ne w reagen t stri p rapi d ureas e tes t fo r detectio n o f Helicobacter pylori infection . Gastrointest Endosc 1996
; 44
: 519-2
2 1 1 Megrau d F . Diagnosti c bacteriologiqu e standar d d e l'infectio n a H. pylori. In : Megrau d F ,

Lamouliatt

e H . (eds ) Helicobacter pylori, Vol 1: Epidemiologie patbogenie, diagnostic. Paris :

Elsevier

, 1996
; 250-6
6 1 2 Glupczynsk i Y . Cultur e o f Helicobacter pylori fro m gastri c biopsie s an d antimicrobia l susceptibilit y testing . In : Le e A , Megrau d F . (eds ) Helicobacter pylori: Techniques for Clinical

Diagnosis

and Basic Research. London : W B Saunders , 1996
; 17-3 2 1 3 Roosendaa l R , Kuiper s EJ , Pen a AS , d e Graaf f J . Recover y o f Helicobacter pylori fro m gastri c biops y specimen s i s not dependen t o n th e transpor t mediu m used . / Clm Microbiol 1995
; 33
:

2798-80

0 1 4 Ha n SW , Flam m R , Hache m C Y et al. Transpor t an d storag e o f Helicobacter pylori fro m gastri c mucosa l biopsie s an d clinica l isolates . Eur J Clm Microbiol Infect Dis 1995
; 14 : 349-5
2 1 5 Hache m CY , Clarridg e JE , Evan s DG , Graha m DY . Compariso n o f aga r base d medi a fo r primar y isolatio n o f Helicobacter pylori. J Clin Pathol 1995
; 48
: 714-
6 18 4 British Medical Bulletin 1998,5
4 (No . 1 )Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Practical diagnosis of H. pylori

16 . Fresnadill o Martine z MJ , Rodrigue z Rinco n M , Blazque z d e Castr o A M et al. Comparativ e evaluatio n o f selectiv e an d non-selectiv e medi a fo r primar y isolatio n o f Hclicobacter pylori fro m gastri c biopsies . Helicobacter 1997
; 2 : 36 -
9 1 7 Jonker s D , Stobbering h E , Stockbrugge r R . Influenc e o f oropharyngea l flor a an d specime n pre - treatmen t o n th e recover y o f Helicobacter pylori. Eur ] Clin Microbiol Infect Dis 1996
; 15 : 378-8
2 1 8 Lag e AP , Godfroi d E , Fauconnie r A et al. Diagnosi s o f Helicobacter pylori infectio n b y PCR : compariso n wit h othe r invasiv e technique s an d detectio n o f cagA gen e i n gastri c biops y specimens . / Clin Microbiol 1995
; 33
: 2752-
6 1 9 Bass o D , Navagli a F , Cassar o M et al. Gastri c juic e polymeras e chai n reaction : a n alternativ e t o histolog y i n th e diagnosi s o f Helicobacter pylori infection . Helicobacter 1996
; 1 : 159-6
4 2 0 Li n SY , Jen g YS , Wan g C K et al. Polymeras e chai n reactio n diagnosi s o f Helicobacter pylori i n gastroduodena l diseases : compariso n wit h cultur e an d histopathologica l examinations . /

Gastroenterol

Hepatol 1996
; 11 : 286-
9 2 1 Thij s JC , va n Zwe t AA , Thij s W J et al. Diagnosti c test s fo r Helicobacter pylori: a prospectiv e evaluatio n o f thei r accuracy , withou t selectin g a singl e tes t a s th e gol d standard . Am ]

Gastroenterol

1996
; 91
: 2125-
9 2 2 Godfroi d E , Mans y F , Fauconnie r A et al. Post-treatmen t diagnosi s o f H. pylori infectio n b y PCR : a compariso n wit h othe r invasiv e technique s [abstract] . Gut 1996
; 3 9 (Suppl . 2) : A11 3 2 3 Roosendaa l R , Kuiper s EJ , va n de n Brul e A J et al. Importanc e o f th e fiberopti c endoscop e cleanin g procedur e fo r detectio n o f Helicobacter pylori i n gastri c biops y specimen s b y PCR . / Clin Microbiol 1994
; 32
: 1123-
6 2 4 Lag e AP , Fauconnie r A , Burett e A et al. Rapi d colorimetri c hybridizatio n assa y fo r detectin g amplifie d Helicobacter pylori DN A i n gastri c biops y specimens . / Clin Microbiol 1996
; 34
: 530-
3 2 5 Alemohamma d MM , Fole y TJ , Cohe n H . Detectio n o f immunoglobuli n G antibodie s t o

Helicobacter

pylori i n urin e b y a n enzym e immunoassa y method . / Clin Microbiol 1993
; 31
: 2174-
7 2 6 Luzz a F , Malett a M , Imene o M et al. Salivary-specifi c immunoglobuli n G i n th e diagnosi s o f

Helicobacter

pylori infectio n i n dyspepti c patients . Am J Gastroenterol 1995
; 90
: 1820-
3 2 7 Fallon e CA , Elizo v M , Clelan d P et al. Detectio n o f Helicobacter pylori infectio n b y saliv a Ig G testing . Am] Gastroenterol 1996
; 91
: 1145-
9 2 8 va n d e Wou w BA , d e Boe r WA , Jans z AR , Royman s RT , Staal s AP . Compariso n o f thre e commerciall y availabl e enzyme-linke d immunosorben t assay s an d biopsy-dependen t diagnosi s fo r detectin g Helicobacter pylori infection . / Clin Microbiol 1996
; 34
: 94-
7 2 9 Meije r BC , Thij s JC , Kleibeuke r JH , va n Zwe t AA , Berrelkam p RJ . Evaluatio n o f eigh t enzym e immunoassay s fo r detectio n o f immunoglobuli n G agains t Helicobacter pylori. J Clin Microbiol 1997
; 35
: 292-
4 3 0 Marchildo n PA , Ciot a LM , Zamaniya n FZ , Peacoc k JS , Graha m DY . Evaluatio n o f thre e commercia l enzym e immunoassay s compare d wit h th e I3 C ure a breat h tes t fo r detectio n o f

Helicobacter

pylori infection . / Clin Microbiol 1996
; 34
: 1147-5
2 3 1 Feldma n RA , Deck s JJ , Evan s SJ . Multi-laborator y compariso n o f eigh t commerciall y availabl e

Helicobacter

pylori serolog y kits . Helicobacter pylori serolog y Stud y Group . Eur } Clin

Microbiol

Infect Dis 1995
; 14 : 428-3
3 3 2 Graha m DY , Evan s J r DJ , Peacoc k J , Bake r JT , Schrie r WH . Compariso n o f rapi d serologica l test s (FlexSur e H P an d QuickVue ) wit h conventiona l ELJS A fo r detectio n o f Helicobacter pylori infection . Am] Gastroenterol 1996
; 91
: 942-
8 3 3 Moayyed i P , Carte r AM , Catt o A , Heppe l RM, Gran t PJ , Axo n ATR . Validatio n o f a rapi d whol e bloo d testin g fo r diagnosin g Helicobacter pylori infection . BMJ 1997
; 314
: 11 9 3 4 Lozniewsk i A , D e Korwi n JD , Conro y MC , Plena t F , Webe r M . Evaluatio n o f Pylorise t Dry , a ne w rapi d agglutinatio n tes t fo r Helicobacter pylori antibod y detection . / Clin Microbiol 1996
; 34
: 1773-
5 3 5 Jone s R , Phillip s I , Feli x G , Tai t C . A n evaluatio n o f near-patien t testin g fo r Helicobacter pylori i n genera l practice . Aliment Pharmacol Ther 1997
; 11 : 101-
5 3 6 Reill y TG , Poxo n V , Sander s DS , Elliot t TS , Wal t RP . Compariso n o f serum , salivary , an d rapi d whol e bloo d diagnosti c test s fo r Helicobacter pylon an d thei r validatio n agains t endoscop y base d tests . Gut 1997
; 40
: 454-
8

British

Medical Bulletin 1998;5
4 (No . 1 ) 18

5Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Helicobacter infection

3 7 Sadowsk i D , Cohe n H , Lain e L et al. Evaluatio n o f th e Flexsur e H P fingerstic k bloo d tes t fo r th e detectio n o f Helicobacter pylori infectio n [abstract] . Gastroenterology 1996;
110
: A24 6 3 8 Ston e MA , Mayberr y JF , Wick s AC B et al. Nea r patien t testin g fo r Helicobacter pylori: a detaile d evaluatio n o f th e Cortec s Helisa l rapi d bloo d test . Eur J Gastroenterol Hepatol 1997
; 9 : 257-6
0 3 9 Che n TS , Chan g FY , Le e SD . Serodiagnosi s o f Helicobacter pylori infection : compariso n an d correlatio n betwee n enzyme-linke d iramunosorben t assa y an d rapi d serologica l tes t results . / Clin Microbiol 1997
; 35
: 184-
6 4 0 Nilsso n I , Ljung h A , AJeljun g P , Wadstro m T . Immunoblo t assa y fo r serodiagnosi s o f

Helicobacter

pylori infections . / Clin Microbiol 1997
; 35
: 427-3
2 4 1 Cove r TL , Glupczynsk i Y , Lag e A P et al. Serologi c detectio n o f infectio n wit h cagA *

Helicobacter

pylori strains . / Clm Microbiol 1995
; 33
: 1496-50
0 4 2 Cutle r AF , Havsta d S , M a CK , Blase r MJ , Perez-Pere z GI , Schuber t TT . Accurac y o f invasiv e an d noninvasiv e test s t o diagnos e Helicobacter pylori infection . Gastroenterology 1995
; 109
: 136-4
1 4 3 Hirsch l AM , Brandstatte r G , Dragosic s B et al. Kinetic s o f specifi c Ig G antibodie s fo r monitorin g th e effec t o f anti-Hehcobacter pylori chemotherapy . / Infect Dis 1993
; 168
: 763 -
6 4 4 Malfertheine r P , Megrau d F , O'Morai n C et al. [Europea n Helicobacter pylori Stud y Grou p (EHPSG)] . Curren t Europea n concept s i n th e managemen t o f Helicobacter pylori infectio n - Th e Maastrich t Consensu s Repor t (Review) . Gut 1997
; 41
: 8-1 3 18 6 British Medical Bulletin 1998;5
4 (No . 1 )Downloaded from https://academic.oup.com/bmb/article/54/1/175/265759 by guest on 27 July 2023

Histology Documents PDF, PPT , Doc

[PDF] blood histology practice test

1. Science

2. Health Science

3. Histology

[PDF] bone histology help worksheet

[PDF] bone histology practice test

[PDF] brs histology download

[PDF] butterfly histology

[PDF] can you have a endometrial biopsy during your period

[PDF] corneal button histology

[PDF] dental histology chapter 7

[PDF] difference between histology and anatomy

[PDF] difference between histology and serology

12345 Next 200000 acticles