AID in aging and autoimmune diseases

Abstract

The aim of this study was to evaluate the quality of B cell responses in patients with Inflammatory Bowel Disease (IBD) and healthy individuals of different ages, vaccinated with the pandemic (p)2009 influenza vaccine. The in vivo response was measured by the hemagglutination inhibition (HAI) assay, which represents the most established correlate with vaccine protectiveness. The in vitro response was measured by activation-induced cytidine deaminase (AID) in cultures of vaccine-stimulated PBMC. Both responses are somewhat impaired in IBD patients undergoing anti-TNF-α treatment but these are much more decreased in IBD patients undergoing treatment with anti-TNF-α and immunosuppressive (IS) drugs. These latter patients had in vivo and in vitro B cell responses similar to those of elderly individuals. Moreover, as we have previously demonstrated in healthy subjects, the in vitro response to the polyclonal stimulus CpG may be used as a biomarker for subsequent vaccine response and AID activation is correlated with the serum response in IBD patients, as it is in healthy individuals. These results altogether indicate that IBD patients on anti-TNF-α and IS have significantly impaired in vivo and in vitro B cell responses, as compared to those on monotherapy. This is the first report to demonstrate that B cell defects, as measured by the autonomous AID reporter, in IBD patients contribute to reduced humoral responses to the influenza vaccine, as we have previously shown for elderly individuals.

Keywords::

• AID (activation-induced cytidine deaminase)
• B lymphocytes
• IBD (Inflammatory Bowel Disease)
• p2009 (pandemic 2009) influenza vaccine
• aging

Acknowledgements

We would like to express our gratitude to the people who participated in this study. We thank nurses and doctors at the Universita' Cattolica del Sacro Cuore in Rome and at the Family Medicine Department of the University of Miami Miller School of Medicine, in particular Dr. Robert Schwartz, chairman and Susie Batista, for the recruitment of healthy volunteers; and Dr. Sandra Chen-Walta, Employee Health Manager. This study was supported by NIH AG-32576 (BBB).

Declaration of interest : The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.