Non-invasive diagnosis of H pylori infection: evaluation of serological tests with and without current infection marker CIM.
OBJECTIVE
To evaluate the performance of commercially available immunochromatographic (ICT) and immunoblot tests covering the current infection marker CIM and conventional ELISA for the diagnosis of H pylori infection in adult dyspeptic patients.


METHODS
Consecutive non-treated dyspeptic patients undergoing diagnostic endoscopy were tested for H pylori infection by culture, rapid urease test, and histology of gastric biopsy specimens. Serum from 61 H pylori infected and 21 non-infected patients were tested for anti-H pylori IgG antibodies by commercial ELISA (AccuBind ELISA, Monobind, USA), ICT (Assure H pylori Rapid Test, Genelabs Diagnostics, Singapore), and immunoblot (Helico Blot 2.1, Genelabs Diagnostics, Singapore) assays. ICT and immunoblot kits cover CIM among other parameters and their performance with and without CIM was evaluated separately.


RESULTS
Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ELISA were 96.7%, 42.8%, 83.1%, 81.8%, and 82.9%, of ICT were 90.1%, 80.9%, 93.2%, 73.9%, and 87.8%, of ICT with CIM were 88.5%, 90.4%, 96.4%, 73.0%, and 89.0%, of immunoblot were 98.3%, 80.9%, 93.7%, 94.4%, and 93.9%, and of immunoblot with CIM were 98.3%, 90.4%, 96.7%, 95.0%, and 96.3%, respectively.


CONCLUSIONS
Immunoblot with CIM had the best performance. ICT with CIM was found to be more specific and accurate than the conventional ELISA and may be useful for non-invasive diagnosis of H pylori infection.
Rahman
Sufi-H Z
SH
Department of Immunology,Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, Dhaka, Bangladesh. sufihannan@yahoo.com
Azam
M-Golam
MG
Rahman
M-Anisur
MA
Arfin
M-S
MS
Alam
M-Mahbub
MM
Bhuiyan
Tareq-M
TM
Ahmed
Nasim
N
Rahman
Motiur
M
Nahar
Shamsun
S
Hassan
M-S
MS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D002845:Chromatography / Q000379:methods; D004415:Dyspepsia / Q000175:diagnosis / Q000473:pathology; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000473:pathology
D000942:Antigens, Bacterial; D015415:Biomarkers; D011933:Reagent Kits, Diagnostic