Abstract

Histamine receptor 2 (H2R) blockade is commonly used in patients with gastric, duodenal ulcers or gastroesophageal reflux disease. Beyond the gastrointestinal tract, H2R is expressed by multiple immune cells, yet little is known about the immunomodulatory effects of such treatment. Clinical reports have associated H2R blockade with leukopenia, neutropenia, and myelosuppression, and has been shown to provide clinical benefit in certain cancer settings. To systematically assess effects of H2R blockade on key immune parameters, a single-center, single-arm clinical study was conducted in 29 healthy subjects. Subjects received daily high dose ranitidine for 6 weeks. Peripheral blood immunophenotyping and mediator analysis were performed at baseline, 3 and 6 weeks into treatment, and 12 weeks after treatment cessation. Ranitidine was well-tolerated, and no drug related adverse events were observed. Ranitidine had no effect on number of neutrophils, basophils or eosinophils. However, ranitidine decreased numbers of B cells and IL-2Rα (CD25) expressing T cells that remained lower even after treatment cessation. Reduced serum levels of IL-2 were also observed and remained low after treatment. These observations highlight a previously unrecognised immunomodulatory sustained impact of H2R blockade. Therefore, the immune impacts of H2R blockade may require greater consideration in the context of vaccination and immunotherapy.

Details

Title
Histamine receptor 2 blockade selectively impacts B and T cells in healthy subjects
Author
Dihia, Meghnem 1 ; Oldford, Sharon A 2 ; Haidl Ian D 1 ; Barrett, Lisa 2 ; Marshall, Jean S 3 

 Dalhousie University, Dalhousie Human Immunology and Inflammation Group, Department of Microbiology and Immunology, Halifax, Canada (GRID:grid.55602.34) (ISNI:0000 0004 1936 8200) 
 Dalhousie University, Dalhousie Human Immunology and Inflammation Group, Department of Microbiology and Immunology, Halifax, Canada (GRID:grid.55602.34) (ISNI:0000 0004 1936 8200); Dalhousie University, Senescence, Aging, Infection and Immunity Laboratory, Department of Medicine, Halifax, Canada (GRID:grid.55602.34) (ISNI:0000 0004 1936 8200); Nova Scotia Health Authority, Division of Infectious Diseases, Halifax, Canada (GRID:grid.458365.9) (ISNI:0000 0004 4689 2163) 
 Dalhousie University, Dalhousie Human Immunology and Inflammation Group, Department of Microbiology and Immunology, Halifax, Canada (GRID:grid.55602.34) (ISNI:0000 0004 1936 8200); Nova Scotia Health Authority, Division of Infectious Diseases, Halifax, Canada (GRID:grid.458365.9) (ISNI:0000 0004 4689 2163) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2520052295
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.