Abbas, Zaigham

Yakoob, Javed

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eCommons@AKUSection of Gastroenterology Department of MedicineOctober 2014Agreement between Serology and Histology fordetection of Helicobacter pylori infectionJaved YakoobAga Khan University, javed.yakoob@aku.eduZaigham AbbasAga Khan University, zaigham.abbas@aku.eduFollow this and additional works at: http://ecommons.aku.edu/pakistan_fhs_mc_med_gastroenterolPart of the Digestive System Diseases Commons, and the Gastroenterology CommonsRecommended CitationYakoob, J., Abbas, Z. (2014). Agreement between Serology and Histology for detection of Helicobacter pylori infection. Journal of theCollege of Physicians and Surgeons Pakistan, 24(10), 779-781.Available at: http://ecommons.aku.edu/pakistan_fhs_mc_med_gastroenterol/84Sir,I read the article by Iqbal et al. published in JCPSP2013, Vol. 23 (11): 784-786 with great interest.1 Theauthors aimed to make a comparison between serologyand histology for detection of Helicobacter (H.) pyloriinfection. Among the 50 study subjects, 30 (60%)subjects were found positive for H. pylori infection withserological testing. Twenty-five (50%) subjects wereidentified positive for H. Pylori infection with histo-pathological diagnosis. Among 30 seropositive subjects,5 subjects found no evidence of H. pylori infection withhistological evaluation. As a result, the authors reporteda substantial agreement between serology and histo-pathology to detect the H. pylori infection (Cohen'sKappa coefficient, 0.72). I appreciate the efforts of theauthors but some points need to be clarified beforemaking a judgement about the results of the study.In patients with atrophic gastritis, the diagnosis of activeH. pylori infection is difficult. During the progressioncourse of atrophy, the density of H. pylori in the stomachmucosa decreases, and during the late stages ofatrophy the infection may completely disappear.2 Thedensity of H. pylori colonization may significantlyinfluence test results. Additionally, the endoscopicdiagnosis of H. pylori infection in patients with bleedingor perforated duodenal ulcers is limited by a decreasedsensitivity in standard invasive tests, rapid urease testand histology.3The prepyloric antrum has been the preferred site ofbiopsy. The sensitivity of distal antral biopsy was96 - 97% and the sensitivity of two biopsies from virtuallyanywhere in the stomach was 100%.4 The stainingtechnique used for the identification of H. pylori is asimportant as the site and number of biopsies. Forexample sole reliance on haematoxylin and eosin whenthe density of H. pylori is low, is unwise and giemsastaining may improve the diagnostic accuracy in thesecircumstances.3Considering the data presented above I would like to askthe authors of the present series as to how manybiopsies were obtained and what was the gastric site ofdiagnosis? What were the endoscopic diagnosis inthese patients? Which stains were used for thehistopathological diagnosis of H. pylori? Was there anyclinical parameter that could influence the results of thehistopathological evaluation, e.g. previous H. pyloritreatment or recent use of proton pump inhibitor?I think the answers to these questions would improve thepower of this study.REFERENCES1. Iqbal S, Fatima S, Raheem A, Khan AH. Agreement betweenserology and histology for detection of Helicobacter pyloriInfection. J Coll Physicians Surg Pak 2013; 23:784-6. 2. Kokkola A, Kosunen TU, Puolakkainen P, Sipponen P,Harkonen M, Laxen F, et al. Spontaneous disappearance ofHelicobacter pylori antibodies in patients with advancedatrophic corpus gastritis. APMIS 2003; 111:619-24.3. Cohen H, Laine L. Endoscopic methods for the diagnosis ofHelicobacter pylori. Aliment Pharmacol Ther 1997; 11:3-9.4. Genta RM, Graham DY. Comparison of biopsy sites for thehistopathological diagnosis of Helicobacter pylori: a topographicstudy of H. pylori density and distribution. Gastrointest Endosc1994; 40:342-5.Sir,We read the recent report “A substantial agreementfound between serology and histopathology results todetect the Helicobacter pylori infection” by Iqbal et al.with reservation. Fifty subjects were included by non-probability purposive sampling from laboratory data whohad serological testing of H. pylori IgG antibody, prior tohistological evaluation of endoscopic gastric or/andduodenal biopsies. Thirty (60%) subjects were foundpositive for H. pylori infection with serological testing.However, 25 (50%) subjects were identified positive forH. pylori with histopathological diagnosis. Among 30seropositive subjects, 5 subjects found no evidence ofH. pylori infection with histological evaluation. Authorsconcluded that “serology assesses the presence ofH. pylori in the stomach even when the bacteria areirregularly distributed on the gastric mucosa and may bemissed on taking biopsy”.Journal of the College of Physicians and Surgeons Pakistan 2014, Vol. 24 (10): 779-781 779LETTER TO THE EDITORHistopathological Diagnosis ofHelicobacter pylori: InfluencingFactorsIbrahim Koral OnalDepartment of Gastroenterology, Ankara Oncology Educationand Research Hospital, Gastroenterology Unit, Ankara,Turkey.Correspondence: Dr. Ibrahim Koral Onal, Mehmet Akif ErsoyMahallesi 13. Cadde No. 56, Yenimahalle/Ankara PC:06200,Turkey.E-mail: koralonal@yahoo.comReceived: November 11, 2013;   Accepted: May 08, 2014.Agreement Between Serologyand Histology for Detection ofHelicobacter pylori InfectionThe choice of diagnostic test for H. pylori depends uponcost, availability, clinical situation, population prevalenceof infection, pretest probability of infection, factors thatinfluence certain test results such as proton pumpinhibitors and antibiotics. Methods available for detectingH. pylori infection include serology, rapid urease test,histology, 13/14 C-urea breath test (UBT) andpolymerase chain reaction. The results of rapid ureasetest, histology and UBT are all affected by previousintake of antibiotics, acid reducing drugs e.g., protonpump inhibitor and histamine-2-receptor blockers. It wasnot informed whether the biopsy samples were collectedfrom patients who were on any of these medicinespreviously.1-3On the basis of a serology, one can not be able to decidewhether to treat or not. A positive result with serologydoes not tell whether the patient has current infection orhad a past infection that is now cured.4,5 Serology isinferior to active testing in sensitivity and especiallyspecificity. The false-positive results include both actualfalse positives for active infection and true positive forantibody, not infected. The drawbacks are treatment ofpeople who are not actively infected, waste of resources,inconveniences to patients, contribution to antibioticresistance. This method is reliable only for populationsurveys and not for individual patients. Serum IgGagainst H. pylori suggests gastric mucosal immuno-logical response against H. pylori infection. It certainlydoes not assess the presence of H. pylori irregularlydistributed on the gastric mucosa something that is doneby the UBT in the gastric mucosa. The current practiceof using positive H. pylori serology for commencingtreatment needs to be discouraged in primary carepractice.REFERENCES1. Yakoob J, Abid S, Jafri W, Abbas Z, Islam M, Ahmad Z.Comparison of biopsy-based methods for the detection ofHelicobacter pylori infection. Br J Biomed Sci 2006; 63:159-62.2. Yakoob J, Jafri W, Abid S, Jafri N, Abbas Z, Hamid S, et al.Role of rapid urease test and histopathology in the diagnosisof Helicobacter pylori infection in a developing country. BMCGastroenterol 2005; 5:38. 3. Yakoob J, Jafri W, Abbas Z, Abid S, Islam M, Ahmed Z. Thediagnostic yield of various tests for Helicobacter pylori infectionin patients on acid-reducing drugs. Dig Dis Sci 2008; 53:95-100. 4. Helicobacter pylori in developing countries [Internet], 2010.Available from: http://www.kibion.se/content/uploads/2013/06/WGO-Guidelines-2010 helicobacter_pylori_developing_countries5. Chey WD, Wong BC. Practice Parameters Committee of theAmerican College of Gastroenterology. American College ofGastroenterology guideline on the management of Helicobacterpylori infection. Am J Gastroenterol 2007; 102: 1808-25.Authors’ Reply (to both letters):We thank the readers for their comments and theopportunity to clarify a number of points from our work.We looked at the agreement between serology andhistology of H. pylori infection. In our small series ofcases, we are saying that serological testing for IgGprovides an inexpensive, non-invasive and convenientmethod to detect H. pylori infection having substantialagreement with histology in our setting. It is important tounderstand that ideally non-invasive testing should belimited to H. pylori tests that detect active infection onlywhich include stool antigen test and urea breath test.Serologic antibody tests do not distinguish betweencurrently active infection with a past exposure and aninfection that has been cured.Endoscopic biopsy remains a gold standard diagnostictest for active Helicobacter pylori (H. pylori) infection;however, it is an invasive and costly technique. Byprecisely guiding diagnosis and treatment; histologypotentially reduced the number of patients inappro-priately treated but the cost-effectiveness analysissupports the continued practice of initial non-invasiveapproaches to guide antibiotic use.World over, there is a shift in diagnosis from testing withIgG to H. pylori antigen testing of human stool byenzyme immunoassay or immune chromatography andurea breath test, which measures radio-labeled carbondioxide by a mass spectrometer or scintillation counter.Both the tests are currently not available in our setupand have their limitations. Serological testing can beregarded as representing a primary approach forevaluation of H. pylori status in patients with uncompli-cated dyspeptic disease, who do not immediatelyrequire endoscopic studies or previously not treated forpeptic ulcer disease, especially in a setup like ourswhere the seroprevalence of H. pylori is about 58-60%.H. pylori serological tests detect antibodies to H. pyloriwith a sensitivity and specificity of approximately 90%.In populations with high disease prevalence, the positivepredictive value of the test rises dramatically, thusfacilitating diagnosis and subsequent treatment ifinvasive testing is not required or opted.Moreover, the management of H. pylori infectionrequires a multi-disciplinary approach and it is stronglyrecommended that there should be close localcollaboration and interaction between primary careLetter to the editor780 Journal of the College of Physicians and Surgeons Pakistan 2014, Vol. 24 (10): 779-781Javed Yakoob and Zaigham Abbas Department of Medicine, The Aga Khan University Hospital,Karachi.Correspondence: Dr. Javed Yakoob, 232/1, Beach Street 1,Khayaban-e-Roomi, Phase 8, DHA, Karachi.E-mail: javed.yakoob@aku.eduReceived: January 09, 2014;   Accepted: May 08, 2014.physicians, specialist gastroenterologists, micro-biologists and possibly public health doctors. Non-invasive tests are options of choice in primary caresetting. Adding testing for H. pylori infection to history-taking has been recommended in patients at high risk ofhaving peptic ulcer disease. It would avoid endoscopiesin some patients and lead to more accurate treatment ofpeptic ulcer disease in most patients. Furthermore, aproportion of dyspeptic patients presenting in primarycare for the first time are patients with peptic ulcerdisease who are H. pylori positive and could get benefitfrom diagnosis and consequent treatment of theinfection.Infection with H. pylori can be patchy, and, as a result,multiple biopsy specimens may be necessary fordiagnosis with endoscopy. However, this is at thediscretion of gastroenterologist performing the endo-scopy. In our series of cases atleast two biopsies weretaken from gastric antrum. In contrast, serologydemonstrates the systemic humoral response and thuspresence or absence of disease, irrespective of patternof distribution of H. pylori, in the gastric mucosa.Our article is based on retrospective analysis of dataand unfortunately we do not have a robust explanationfor the missing clinical information. Due to the absenceof a national health system the complete clinicalinformation by physicians like the previous treatmentand use of proton pump inhibitors is hardly provided. Wepropose performing a prospective clinical trial that wehope will be able to provide a more robust answer tosome of the questions that have been raised.Letter to the editorJournal of the College of Physicians and Surgeons Pakistan 2014, Vol. 24 (10): 779-781 781Ayesha Habib Khan, Sahar Iqbal and Samia Fatima Department of Pathology and Microbiology, The Aga KhanUniversity Hospital, Karachi.Correspondence: Dr. Ayesha Habib Khan, 116 A/II, 16thStreet, Off Khayaban-e-Mujahid, Phase VI, DHA, Karachi.E-mail: aysha.habib@aku.eduReceived: January 9, 2014;   Accepted: May 08, 2014.

Agreement between Serology and Histology for detection of Helicobacter pylori infection

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Agreement between Serology and Histology for detection of Helicobacter pylori infection

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