Gut 1997; 40: 454-458

Comparison of serum, salivary, and rapid wholeblood diagnostic tests for Helicobacter pylori andtheir validation against endoscopy based tests

T G Reilly, V Poxon, D S A Sanders, T S J Elliott, R P Walt

AbstractBackground-A rapid, reliable, and ac-curate test for the diagnosis of infectionwith Helicobacter pylon is needed forscreening dyspeptic patients before refer-ral for endoscopy.Aim-To compare a new rapid wholeblood test (Helisal rapid blood, Cortecs),two serum enzyme linked immunosorbentassays (ELISAs; Helico-G, Shield andHelisal serum, Cortecs), and a salivaryassay (Helisal saliva, Cortecs), with slidebiopsy urease, "C-urea breath test, andhistology.Methods-Three hundred and three con-secutive dyspeptic patients attending forgastroscopy underwent two antral biop-sies for histology, and one for rapid slidebiopsy urease test for assessment of Hpyloni status. Blood and saliva were alsocollected. One hundred of the patientsalso underwent a "C-urea breath test.Gold standard positives were defined asthose with at least two positive testsamong slide urease, breath test, or his-tology, and gold standard negatives asthose with all these (or two when thebreath test was not done) negative.Results-Of 300 patients (median age 63,range 28-89) eligible for analysis, 137(46%) were gold standard positives, ofwhich Helisal rapid blood identified 116,Helico-G 129, Helisal serum 130, andHelisal saliva 120; 137 (46%) were goldstandard negatives of which the numberfalsely identified as positive was 30 byHelisal rapid blood, 45 by Helico-G, 41 byHelisal serum, and 41 by Helisal saliva.Sensitivities and specificities were: for thewhole blood test 85% and 78% res-pectively; for Helico-G 94% and 67%, forHelisal serum 95%/o and 70°/o, and forHelisal saliva 84% and 70%.Conclusions-If endoscopy had beenundertaken only on patients with positivetests two of 16 duodenal ulcers would havebeen missed if the Helisal rapid blood testwas used, and one ifany ofthe ELISA testswere used. None of the blood tests wouldhave missed any of six gastric ulcers, butthe salivary test would have missed one.(Gut 1997; 40: 454-458)

Keywords: Helicobacterpylori diagnosis, ELISAserology, rapid whole blood test, "C-urea breath test,histology.

There are many methods available for thediagnosis of Helicobacter pylori. Some requireupper gastrointestinal endoscopy to gainmaterial for diagnosis, whereas non-invasivetests can be performed on serum, saliva, or

expired breath samples. It has been suggestedthat screening for the presence of the organismbefore referral for upper gastrointestinal endos-copy' would allow resources to be directedtowards those in whom pathology that isserious is likely to be encountered. It has beenshown that H pyloni status as determined byserology predicts endoscopic findings more

accurately than formal questioning.2 If thisstrategy were to be widely adopted an in-expensive, reliable, and rapid diagnostic testthat is acceptable to patients and clinicianswould be needed.

AimsThe study was designed primarily to comparethe performance of several candidate screeningtests, including a new rapid whole blood test(Helisal rapid blood, Cortecs Diagnostics,Clwyd) which is a near patient test giving aresult within 10 minutes, with other estab-lished tests for the diagnosis of H pyloni.Subsidiary aims were to show whether cor-relations exist between the titre of differentquantifiable assays for H pyloni antibodies andthe endoscopic findings, and between the titreand the density of H pylori infestation of thegastric mucosa.

MethodsThree hundred and three consecutive patientsattending the endoscopy department of theQueen Elizabeth Hospital for "direct access"upper gastrointestinal endoscopy were re-cruited to take part in the study, which had theapproval of the South Birmingham researchethics committee. The department operates ascreening policy whereby open access endos-copy is not provided to those below the age of50 with uncomplicated dyspepsia (no worryingsymptoms), unless they have positive H pylonserology.The endoscopic findings were recorded by

any of seven experienced endoscopists (fourconsultants and three research registrars) andthree antral mucosal biopsy specimens weretaken from each patient. Two biopsy speci-mens were sent for histological examination forpathology and the presence of H pylori after

Department ofMedicineTG ReillyV PoxonRP Walt

Department ofHistopathologyDSA Sanders

Department ofMicrobiology, QueenElizabeth Hospital,BirminghamTSJ ElliottCorrespondence to:Dr RP Walt,Heartlands Hospital,Bordsley Green East,Birningham B9 5SS.Accepted for publication20 December 1996

454

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from

Comparison ofserum, salivary, and rapid whole blood diagnostic tests for H pylori and their validation against endoscopy based tests

staining with haematoxylin and eosin, and ifnoHelicobacter organisms were seen a modifiedGiemsa stain was applied. The presence orabsence ofH pylori was noted and the severityof infection graded semiquantitatively from 1to 3, the grades denoting small, moderate, andlarge numbers of Helicobacter seen. Theremaining antral biopsy specimen was usedfor a slide biopsy urease test (CLOtest',DeltaWest Pty, Australia). This was read at 30minutes after insertion of the biopsy, reviewedat 24 hours, and the result recorded.

After endoscopy, 7 ml venous blood wastaken from each subject: this was centrifugedand the serum stored for enzyme linkedimmunosorbent assay (ELISA) for anti-Helico-bacter IgG antibodies. Two test kits wereused (Helico-G, Shield Diagnostics, TechnoPark, Dundee, and Helisal serum, Cortecs)with antibody titres obtained by absorbancemeasurement at 450 nm after coincubation ofimmobilised antigen with test serum, horse-radish peroxidase, and tetramethyl benzidineindicator. Not sooner than 30 minutes afterendoscopy saliva was collected by an absorbentpad placed in the mouth until an indicatorshowed blue (OmnisalTM collection system).The saliva was assayed for H pylon antibodiesusing the Helisal enzyme immunoassay.A drop of blood was taken by lancet

puncture of a fingertip into a capillary tube andthis was tested by a rapid whole blood diag-nostic kit (Helisal rapid blood, Cortecs), aspreviously described. A positive test wasrecorded if any dye was observed in the testarea, and a negative if only the control spotshowed red. When two independent blindedobservers were in agreement that the mark was

TABLE I Perfor-mance of the tests under investigation and of the gold standard tests

Sensitivity (%) ifSensitivity (%/o) indetenminates Specificity(95% CI) positive (95% CI) (95% CI)

Helisal whole blood test 85 (71-91) 78 (71-84) 781 (71-85)Helisal whole blood test 82-5 (76-89) 75 (68-82) 84-9 (79-91)

(excluding faint results)Helico-G 94 (89-97) 87 (82-92) 67 (59-75)Helisal serum 95 (90-98) 90 (85-94) 70 (62-78)Helisal saliva 84 (76-89) 79 (73-85) 70 (62-77)Histology 97 (92-99) 90 (85-95) 100 (97-100)Slide biopsy urease test 91 (85-95) 91 (85-95) 100 (97-100)'"C-urea breath test 100 (91-100) 84 (72-92) 100 (91-100)

The middle column shows the sensitivities which would be found if all those who hadindeterminate results by the gold standard definition were deemed positive.

TABLE II Sydney system grading of histology according to gold standard status in 295patients

Gold Sydney gradeSydney standard % Possible % Withcategory status 0 1 2 3 score any grade

Hpyloi density N 137 0 0 0 0.0 0I 11 15 0 0 192 58P 6 50 49 27 57 8 95

Active gastritis N 128 9 0 0 2 2 7I 22 3 1 0 64 15P 47 44 26 15 35-6 64

Chronic gastritis N 84 50 3 0 13 6 39I 10 12 4 0 25-6 62P 8 53 47 24 55-3 94

Intestinal metaplasia N 128 8 0 1 2-7 7I 22 4 0 0 5-1 15P 116 13 2 1 5-1 12

N=negative (n= 137); I=indeterminate (n=26); P=positive (n= 132).

hard to discern the positives were also noted tobe "faint". One hundred of the patients alsounderwent a '3C-urea breath test (BSIA Ltd,Brook Lane North, Brentford, Middlesex)using the European Standard Protocol onesample method,3 and excess delta '3CO2excretion greater than 5 per mil was taken asa positive result.Gold standard positives were defined as

those with at least two positive tests among therapid slide biopsy urease test, histology, and13C-urea breath test; and gold standardnegatives as those with all these tests negative(three tests or two when the '3C-urea breathtest was not done). Those with conflictingresults (one positive and either one or twonegative) were classed as indeterminate.

ResultsThree hundred and three subjects wereenrolled and 300 were eligible for analysis(median age 62, range 28-89). Three subjectswere excluded because data were missing(antral biopsy specimens were not taken in twocases and the blood sample for serology wasmissing in one case). There were 137 goldstandard positives, of which the whole bloodtest identified 1 6, Helico-G 129, Helisalserum 130, and Helisal saliva 120. Of 137 goldstandard negatives the whole blood test falselyidentified 30 as positive, Helico-G 45, Helisalserum 41, and the salivary assay 53. In 26 casesresults were indeterminate (17 of them had nothad '3C-urea breath tests). Fifteen patients hadpositive histology only and 11 had a positiveslide biopsy urease test only. Excluding theindeterminates the prevalence of H pyloninfection was 50%. Table I shows the sensi-tivities and specificities derived both by ex-cluding the indeterminates and by readingthem as positive.

Faint marks were recorded with the rapidtest in 29 cases. These did not correlate withborderline titres in the ELISA assays. Usingthe cut off of 1 lU/ml for the Helico-G test,nine of 1 13 in the seronegative group were faintcompared with 20 of 187 in the seropositivegroup (p=0 44, x2). Those with faint marksmade up 1 1 of 137 of the gold standardpositives and 16 of 137 of the gold standardnegatives (p=0-31, x2). There were two patientswith faint marks whose gold standard tests wereindeterminate. Table 1 shows results assumingall faint marks to be positive in accordancewith the manufacturers' instructions, and alsoexcluding all faint marks.

HISTOLOGY

Histology results were available in 295 cases,and were lost or unsatisfactory in five. Therewere 154 cases with no organisms seen onmicroscopy, and 141 in which H pylon wasseen, including 65 with small, 49 with moder-ate, and 27 with large numbers of organisms.Table II shows the histological grading accor-ding to the Sydney system4 for each of the goldstandard categories. Table III shows the gradeof infection accorded to each diagnosis and

455

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from

Reilly, Poxon, Sanders, Elliott, Walt

comparisons of each diagnostic group withthe normal subjects. There was a significantdifference between those with peptic ulcerdisease and normal subjects in the proportionwith H pyloni infection (p=00001). All othercomparisons were not significantly different.The grade of infection was also compared withthe antibody titre of the three ELISA assaysstudied (Table IV). All three assays showed asignificant difference in mean titre betweenthose with no histological evidence ofH pylon'infection and those with organisms visible onthe biopsy sample, but there was no differencebetween grades of infection.

DIAGNOSES AND HELICOBACTER PYLORIINFECTIONFor the purposes of this analysis groupingswere made of the diagnoses (Table V). Sixteenpatients with duodenal ulcer and six with

TABLE iII Histological grade ofH pylori infection correlated with endoscopic diagnosis

Any x2v normal0 1 2 3 grade Total (p value)

Normal 72 31 18 8 57 129Antral gastritis* 11 4 3 5 12 23 0-48Peptic ulcer disease 6 12 11 5 28 34 0-0001Duodenitis 6 3 3 3 9 15 0 25Oesophagitist 32 7 10 3 20 52 0 48Hiatus herniat 21 7 4 3 14 35 0-66

*Numbers refer to patients in whom gastritis was the principal diagnosis only: gastritis was anadditional diagnosis in 14 cases with other pathology.tNumbers refer to patients in whom hiatus hernia was the sole diagnosis: it was also noted in afurther 26 cases with oesophagitis.tOesophagitis was an additional diagnosis in one patient with a duodenal ulcer and threepatients with duodenitis.

TABLE iV Mean antibody titres (±95% CIs) compared with histological grade ofH pyloriinfection for each of three assays

Grade ofH pylori infection

0 (n=154) 1 (n=65) 2 (n=49) 3 (n=27)

Helico-G 25-5 (±6-85) 51-3 (±10-85) 619 (±12 8) 55-1 (±19 8)p<0-0001 p<0-0001 p=0-0092

Helisal serum 1-73 (±0 4) 4-26 (±0 77) 5-52 (±0 82) 4-34 (±1 01)p<0-0001 p<0-0001 p=0 0002

Helisal saliva 1-44 (±0 35) 3-27 (±0 75) 3-83 (±0 87) 4 30 (±1-20)p=0-0002 p<0-0001 p=00007

Statistical comparisons are with the histology zero group and are by oneway analysis of variance(ANOVA).

TABLE v Number (%) ofeach diagnosis predicted by a positive serology result

Diagnosis Helisal rapid Helico-G Helisal serum Helisal saliva

Oesophageal cancer (n=5) 2 (40) 3 (60) 2(40) 0Peptic ulcer (n=22) 20 (91) 21 (95) 21(95) 19 (86)Duodenal ulcer (previous) (n=12) 7 (58) 7 (58) 8 (66) 6 (50)Duodenitis (n=16) 11 (69) 12 (75) 12(75) 9 (56)Hiatus hernia (n=35) 17 (49) 19 (54) 20 (57) 18 (51)Normal (n=132) 64 (48) 80 (60) 84 (64) 76 (58)Oesophagitis (n=52) 23 (44) 30 (58) 24 (46) 23 (44)Antral gastritis (n=24) 13 (54) 15 (62 5) 16 (66) 16 (66)

gastric ulcer were grouped as "peptic ulcerdisease". Seven patients with a previouslydocumented duodenal ulcer, two with previoussurgery for ulcer (one partial gastrectomy andone vagotomy and pyloroplasty), and threewith typical scarring and deformity of theduodenum without active ulcer at endoscopy,were grouped as "previous duodenal ulcer".A group of 243 patients labelled "oesophagitisor normal" comprised 57 with oesophagitis(including five with Barrett's oesophagus),129 normal, 35 with hiatus hernia alone, and23 with macroscopic antral gastritis. Fifteenpatients had macroscopic duodenitis alone.There were five patients with cancer of theoesophagus.There were two Helicobacter negative patients

in the peptic ulcer disease group: one patientwith duodenal ulcer was on a non-steroidalanti-inflammatory drug and the other had hadprevious Helicobacter eradication treatment.There were three in the "previous duodenalulcer" group: two with previous ulcer surgeryand one who had had a duodenal ulcerdocumented 15 years previously.The mean antibody titres of the ELISA

assays for each of the four main diagnosticgroups were compared (Table VI). There was

a significant difference between the pepticulcer disease group and the oesophagitis or

normal group for the two serum assays but notthe salivary assay. In addition there was a

significant difference between the peptic ulcerdisease group and the duodenitis and previousduodenal ulcer groups for the Helisal serum

assay.

SUBGROUP ANALYSES

Relevant drugs excludedBecause no exclusion criteria were imposedthere were patients in the study who had hadprevious eradication therapy, or were currentlytaking proton pump inhibitors and non-steroidal anti-inflammatory drugs. An analysiswas undertaken of the performance of the testswith this group excluded. The number ofindeterminates diminished from 26 to 21.Table VII gives the results of this analysis,which showed virtually identical sensitivities tothose of the entire group and improvedspecificities. The sensitivity of the slide biopsyurease test improved from 91% to 1 00%.

Patients under the age of50 yearsThe study included 47 patients under the ageof 50 years and these were examined as a

separate group (Table VIII). Of these, 36 were

H pylori positive (a high proportion, reflecting

TABLE VI Mean (SD) antibody titre grouped by endoscopic diagnosis

Helico-G Helisal serum Helisal saliva

Oesophagitis or normal (n=243) 39-8 (50 3) - 2-96 (3-15) - 2-46 (2-92)Peptic ulcer disease (n=22) 60-9 (37-4) p=0-02 6-02 (2 56) p=<0-001 3-64 (3-00) p=0O09Previous DU (n=12) 35-4 (43-9) p=0 74 3-01 (2-79) p=0-95 2-41 (2 57) p=095Duodenitis (n=15) 47-2 (49-8) p=0 57 3-79 (3-18) p=0-32 2-42 (2 96) p=0-96

Statistical comparisons are with the oesophagitis or normal group and are by oneway ANOVA. DU=duodenal ulcer.

456

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from

Comparison ofserum, salivary, and rapid whole blood diagnostic tests forH pylori and their validation against endoscopy based tests

TABLE vII Results excluding those taking proton pump inhibitors, non-steroidal anti-inflammatory drugs and those who had had previous H pylori eradication therapy

n=261 Sensitivity % (95% CI) Specificity % (95% CI)

Helisal whole blood test 85 (79-91) 79 5(72-87)Helico-G 94-5 (89-98) 71 (63-80)Helisal serum 95 (90-98) 75 (67-83)Helisal saliva 89 (83-94) 64 (55-73)Slide biopsy urease 100 (97-100) 100 (97-100)Histology 95 (90-98) 100 (97-100)"3C-urea breath test 100 (93-100) 100 (89-100)

TABLE Viii Results in the under 50 age group

n=45 Sensitivity (%o) Specificity (0)

Helisal whole blood test 83-3 82-4Helico-G 95-8 70-6Helisal serum 95-8 64-7Helisal saliva 91 7 35-3

TABLTE ix Diagnoses according to age at endoscopy

Under 50 Over 50 Total

Peptic ulcer 2 20 22Duodenal ulcer (previous) 3 9 12Duodenitis 3 13 16Antral gastritis 3 21 24Hiatus hernia 2 33 35Normal 26 106 132Cancer of oesophagus - 5 5Oesophagitis 6 46 52Leiomyoma - 1 1Gastric polyp - 1 1Total 45 255 300

the unit policy). In this group the sensitivityand specificity of the serology tests did notdiffer significantly from those of the group asa whole. Table IX shows the under 50 and over50 age groups broken down according toendoscopic diagnosis.

COMPARISON OF ELISA ASSAYS

The Figure shows a plot of the sensitivity andspecificity of different cut off points for each ofthe three ELISA assays. Separate analysis ofthe group in whom three tests were performedfor the gold standard (100 patients ofwhom 91were not indeterminate) showed traces which

0 20 40 60 80 100 120 140 160 180 200Sp IfiIci

Specificity

I--, ---- Helisal saliva---- Helisal serum

Helico-G

I'l -

411 Sensitivity --

0'I10

'Ii

0 1 2 3 4 5 6 7 8

were superimposable on those shown. Likewiseexclusion of those who had been on protonpump inhibitors, non-steroidal anti-inflam-matory drugs, or had had previous eradicationtherapy made no difference to the sensitivity ofany of the assays although it did make a non-significant improvement to the specificity overthe middle part of the cut off range.

DiscussionThe sensitivity of the Helisal rapid blood testhas been reported to be in the range 63% to91% and the specificity 83% to 94O/o.5-8 In thisgroup of subjects we found it to be 85%sensitive with a specificity of 78%. The sen-sitivity of Helico-G ranges from 7 1/9 to 96% owhereas reported sensitivity and specificity ofthe Cortecs serum ELISA test are 91 2%and 83-3% respectively.1' The sensitivity andspecificity levels we found are in line withthose previously published for both of theseassays. Salivary IgG antibodies to Helicobacterhave been reported to have a sensitivity of890/o-90% and a specificity of 820/o-94%,l2 13and the particular assay we used has previouslybeen validated against a serum assay,'4 andwhen tested clinically'5 it provided a sensitivityof 97% and a specificity of 90%. In our handsthe salivary assessment achieved somewhatlower sensitivity and specificity than thosepreviously reported. However, our studyincluded a much larger group of subjects thanmost previous reports and is in line with otherresults. From our data we conclude that thenew rapid whole blood test has a lower sen-sitivity than desirable if it were to be used todetermine appropriate dyspeptic patients forendoscopy. Such a test requires high sensitivityso that few if any diagnoses associated with Hpylori are missed.The study may be criticised and the

conclusion questioned for various reasons. Theaverage age of our subjects (62) was higherthan that of most series: this is because ourendoscopy unit operates a screening policywhich has the effect of excluding the young andfit from endoscopy. This could reduce thesensitivity of serology based tests because theserological response to H pylori infectiondeclines with age. However, the subgroupanalysis on those under 50 showed similarserology results to those of the whole studypopulation, and this suggests that in ourpopulation age alone cannot account for lowsensitivity of the rapid assay. Similarly, agealone would not explain the difference betweenserum ELISA studies and the rapid blood test.We did not take biopsy specimens from the

gastric body: this omission may have loweredthe number of positives diagnosed by the goldstandard if there were cases in whom H pyloriwas present in the gastric body but not in theantrum as is reported to occur after treatmentwith proton pump inhibitors. 16 It can' be arguedthat the extra biopsy specimens might haveresolved some of the indeterminates. However,in only 1 1 out of the 26 indeterminates was thehistology negative. If all of these had hadpositive corpus biopsy specimens the sensitivity

C._._.,

Cu

a)Ce)

,.r._

ntn)

Cut off (U/mi)Sensitivity and specificity of three ELISA IgG assays for antibodies to H pylori. The topXaxis refers to the Helico-G assay and the bottom X axis to the two Helisal assays.

I.

457

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from

Reilly, Poxon, Sanders, Elliott, Walt

of the rapid whole blood test would have been84% (compared with 85%), of Helico-G92-5% (94%), of Helisal serum 94-6% (95%),and of Helisal saliva 89% (84%). If it wereassumed that the indeterminates were low-level positives, analysis of results (middlecolumn of Table I) shows that their inclusionreduces the sensitivity of all the tests with theexception of the slide biopsy urease test. Onehundred breath tests only were performedbecause of practicality and expense, butseparate analysis of the patients who receivedthem showed similar results to those of thegroup as a whole, suggesting that the goldstandard criteria we chose were adequate.We made no exclusions other than those due

to the screening policy in operation, becausewe thought that the study conditions shouldreflect as closely as possible the conditionsunder which the blood tests are likely to beused. We therefore included some patients whohad previously had eradication therapy, or whohad been taking proton pump inhibitors, whichcan suppress Helicobacter without eradicatingit"7 and who had been on aspirin and non-steroidal anti-inflammatory drugs. Both of thefirst two factors could have led serological teststo overdiagnose infection by comparison withthe gold standard, and hence have affected thespecificity but not the sensitivity. A subanalysisof the group excluding the 41 patients who hadbeen on, proton pump inhibitors, or had haderadication therapy made no difference to thesensitivity of any of the candidate tests whileslightly but not significantly improving thespecificity. The inclusion of those on non-steroidal anti-inflammatory drugs led to theinclusion of one patient with a duodenal ulcerwho was H pylori negative by the goldstandard.The performance of the rapid test in

predicting Helicobacter related pathology wasnot quite as good as that of the two serumELISA tests: our results suggest that the wholeblood test, if used as a screening bar toendoscopy, would result in about 15% of thosewith the infection and 10% of those withcurrent ulcers going undetected. The resultsfor the saliva assay are similar. Our studypopulation was a relatively highly selected oneof dyspeptic patients deemed by their generalpractitioners to require endoscopy. Thereforethey would be expected to have a highprevalence of H pylon. As negative predictivevalue (the chance of a negative result correctlyplacing its subject) increases with lowerprevalence of an organism the confidence withwhich a subject could be declared free ofinfection on the basis of a negative rapid testmay be higher in less selected populations thanours.We would not recommend the routine use

of salivary antibodies as a means to chooseappropriate endoscopy in H pylon positive

patients in whom the test is considered. Therapid whole blood test has the advantages thatit is portable, no special equipment (such ascentrifuges) is required to perform it, and itgives a result within five to seven minutes. Insettings where ELISA assays are not availablea positive result with this kit would be helpfulin decision making, but the result would ideallybe confirmed by other means. The serumELISA assays tested provide higher sensitivitylevels and where available remain our choice.

We thank Professor J Temple, Mr M Hallissey, Mr M Corlett,Dr N Michell, Dr Kate Kane, and the staff of QED and theClinical Investigation Unit of the Queen Elizabeth Hospital fortheir help with this study, which was supported by a grant fromCortecs Ltd.

1 Sobala GM, Crabtree JE, Pentith JA, Rathbone BJ,Shallcross TM, Wyatt JI, et al. Screening dyspepsia byserology to Helicobacter pylori. Lancet 1991; 338: 94-6.

2 Mendall MA, Jazrawi RP, Marrero JM, Molineaux N,Levi J, Maxwell JD, Northfield TC. Serology for Helico-bacter pylori compared with symptom questionnaires inscreening before direct access endoscopy. Gut 1995; 36:330-3.

3 European standard protocol. Eur Jf Gastroenterol Hepatol1991; 3: 915-21.

4 Price AB. The Sydney system: histological division. JGastroenterol Hepatol 1991; 6: 209-22.

5 Duggan AE, Knifton A, Logan RPH, Hawkey CJ,Logan RFA. Validation of two new rapid blood tests forHelicobacter pylori. Gut 1995; 37(suppl 2): A85.

6 Lahaie RG, Ricard N. Validation of Helisal whole blood,serum and saliva tests for the non-invasive diagnosis ofHelicobacter pylori infection. Gut 1995; 37(suppl 1):A13.

7 Millar Jones D, Yapp T, Thomas GAO, Pugh S. A newrapid whole blood test for Helicobacter pyloriantibodiescould reduce diagnostic oesophagogastroduodenoscopy(OGD) in patients with dyspepsia. Gut 1994; 35(suppl 5):S1.

8 Moayeddi P, Carter AM, Heppell RM, Catto AJ, Grant P,Axon ATR. Validation of a new rapid whole blood testfor the diagnosis of Helicobacter pylori infection. Gut1995; 36(suppl 1): A51.

9 Jensen AK, Andersen LP, Wachmann CH. Evaluation ofeight commercial kits for Helicobacter pylori IgGantibody detection. APMIS 1993; 101: 795-801.

10 Uyub AM, Anuar AK, Aiyar S. Reliability of two com-mercial serological kits for serodiagnosing Helicobacterpyloriinfection. Southeast Asian J Trop Med Public Health1994; 25: 316-20.

11 Pugh S, Swift J, Landeg S. Helicobacter pyloriIgG antibodystatus in hospital staff groups: results using thecortecsELISA test. In: Abstracts submitted for Helicobacterpylori: beginning the second decade-the VIIth workshopof the European Helicobacter pyloriStudy Group, 1994.AmJ Gastroenterol 1994; 89: 1285-422.

12 Patel P,Mendall MA, Khulusi S, Molineaux N, Levy J,Maxwell JD, Northfield TC. Salivary antibodies toHelicobacter pylori: screening dyspeptic patients beforeendoscopy. Lancet 1994; 344: 511-2.

13 Clancy RL, Cripps AW, Taylor DC, McShane L,Webster VJ. The clinical value of a saliva diagnostic assayfor antibody to H pylori. In: Hunt RH, Tytgat GNJ, eds.Helicobacter pylori -basic mechanisms to clinical cure.Proceedings of the International Symposium held inAmelia Island, Florida USA, 3-6 November 1993.Dordrecht: Kluwer Academic, 1994.

14 Phull P, Goodwin P, Guard P, et al. Detection of salivaantibody to H pylori by the HelisalTm enzyme-linkedimmunosorbent assay. In: Hunt RH, Tytgat GNJ, eds.Helicobacter pylori- basic mechanisms to clinical cure.Proceedings of the International Symposium held inAmelia Island, Florida USA, 3-6 November 1993.Dordrecht: Kluwer Academic, 1994.

15 Lahaie RG, Ricard N. Validation of helisal whole blood,serum and saliva tests for the non-invasive diagnosis ofHelicobacter pylori infection. Gut 1995; 37(suppl 1):A13.

16 Logan RP, Walker MM, Misiewicz JJ, Gummett PA,Karim QN, Baron JH. Changes in the intragastricdistribution of Helicobacter pylori during treatment withomeprazole. Gut 1995; 36: 12-6.

17 Weil J, Bell GD, Powell K, et al. Omeprazole andHelicobacter pylori: temporary suppression rather thantrue eradication. Aliment Pharmacol Ther 1991; 5:309-13.

458

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from

based tests.pylori and their validation against endoscopy

Helicobacterwhole blood diagnostic tests for Comparison of serum, salivary, and rapid

T G Reilly, V Poxon, D S Sanders, T S Elliott and R P Walt

doi: 10.1136/gut.40.4.4541997 40: 454-458 Gut

http://gut.bmj.com/content/40/4/454Updated information and services can be found at:

These include:

serviceEmail alerting

box at the top right corner of the online article. Receive free email alerts when new articles cite this article. Sign up in the

CollectionsTopic Articles on similar topics can be found in the following collections

(484)Ulcer (1689)Stomach and duodenum

(1003)Endoscopy

Notes

http://group.bmj.com/group/rights-licensing/permissionsTo request permissions go to:

http://journals.bmj.com/cgi/reprintformTo order reprints go to:

http://group.bmj.com/subscribe/To subscribe to BMJ go to:

group.bmj.com on April 18, 2018 - Published by http://gut.bmj.com/Downloaded from