Serum antibodies to selected Helicobacter pylori antigens are associated with active gastritis in patients seen at the University Teaching Hospital in Lusaka, Zambia

Violet Kayamba^{1, 2}, Julia Butt³. Matthew Gordon Varga⁴, Aaron Shibemba⁵, Maria Blanca Piazuelo⁶, Keith Tucker Wilson^{6, 7}, Kanekwa Zyambo¹, Simutanyi Mwakamui¹, Chola Mulenga¹, Tim Waterboer³, Meira Epplein⁸, Douglas Corbett Heimburger⁹, Masharip Atadzhanov², Paul Kelly^1,2,10

1. Tropical Gastroenterology & Nutrition group, Department of Internal Medicine, PO Box 50398, Nationalist Road, Lusaka, Zambia.
2. University of Zambia School of Medicine, Department of Internal Medicine, PO Box 50110, Nationalist Road, Lusaka, Zambia.
3. Infection and Cancer Epidemiology Group, German Cancer Research Center (DKFZ), Heidelberg, Germany.
4. Department of Epidemiology, UNC Gillings School of Global Public Health and the Lineberger Comprehensive Cancer Center, 3207B Michael Hooker Research Center, Chapel Hill, NC 27599 USA.
5. University Teaching Hospital, Department of Pathology, Private Bag RW IX, Nationalist Road, Lusaka, Zambia.
6. Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, 37232, Tennessee, USA.
7. Veterans Affairs Tennessee Valley Healthcare System, Nashville, 37212, Tennessee, USA.
8. Cancer Risk, Detection, and Interception Program, Duke Cancer Institute, and Department of Population Health Sciences, Duke University, Durham, North Carolina, USA.
9. Vanderbilt Institute of Global Health, Vanderbilt Medical Center, 2525 West End Avenue, Suite 750, Nashville, 37203, Tennessee, USA.
10. Blizard Institute, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT,UK

*Corresponding Author: Violet Kayamba; Email: viojole@yahoo.com

Abstract

Introduction

Little is known about specific bacterial characteristics of Helicobacter pylori (H. pylori) infection influencing gastric carcinogenesis in Zambia. The aim of this study was to evaluate the associations between pre-selected H. pylori antibodies with gastric cancer, premalignant lesions and active gastritis.

Methods

This was cross-sectional study with multiple comparisons of patients with gastric cancer (GC), gastric premalignant (GP) lesions and active or chronic gastritis. A fluorescent bead-based antibody multiplex serology assay was used to quantify antibodies to thirteen immunogenic H. pylori antigens. Logistic regression models were used to examine the associations.

Results

Included were 295 patients with: 59 GC, 27 GP lesions, 48 active and 161 chronic gastritis. Overall, 257/295 (87%) were H. pylori positive. H. pylori seropositivity was not associated with sex, age, body mass index, socio-economic status, HIV infection, alcohol consumption or cigarette smoking (p-values all above 0.05). When compared to the patients with chronic gastritis, the presence of catalase and cinnamyl alcohol dehydrogenase (Cad) antibodies was positively associated with GP lesions (OR 3.53; 95% CI 1.52-8.17 and OR 2.47; 95% CI 1.08-5.67 respectively). However, seropositivity to Cad antibodies was significantly lower in GC patients (OR 0.28; 95% CI 0.09-0.83). Compared to chronic, active gastritis was significantly associated with (p<0.05) H. pylori sero-positivity (OR 9.46; 95% CI 1.25-71.52) and specific antibodies including cytotoxin-associated gene A, vacuolating cytotoxin A, Helicobacter cysteine-rich protein C, hypothetical protein HP0305 and outer membrane protein HP1564.

Conclusions

Among Zambian patients seen at a single center, antibodies to H. pylori (CagA, VacA, Omp, HcpC, HP0305 and HpaA) were associated with active gastritis.

Key words; Gastric cancer; Helicobacter pylori; Zambia