The influenza vaccine in type 2 patients can….
This study aimed to evaluate the immune response in young and elderly patients with type 2 diabetes with the seasonal influenza vaccine. Subjects included 37 healthy young, 28 healthy elderly, 14 diabetic young and 8 diabetic elderly volunteers. In this study young individuals were defined as 20-59 years of age, whereas elderly individuals were ≥60 years of age. After subjects in the study were administered the flu shot the immune response was evaluated by measuring an in vivo serum response to the vaccine via hemagglutination inhibition (HAI). To measure optimal response to the vaccine, B cell-specific biomarkers were measured ex vivo by switched memory B cells and plasmablasts in vitro by activation-induced cytidine deaminase (AID) in stimulated cells. These biomarkers were used based on results from two previous influenza vaccine studies involving the influenza seasonal vaccines and the 2009 pandemic vaccine. The findings from these prior studies confirmed that AID can accurately track optimal immune responses and is regarded as a valid biomarker for humoral responses to the influenza vaccine in humans. AID, therefore, is also a good biomarker of antibody activity and responses in type 2 diabetic patients.
Concluding results to this study revealed that young and elderly type 2 diabetic patients have normal in vivo and in vitro B cell responses to the influenza vaccine. Earlier studies which evaluated the effect of diabetes on the influenza vaccine-specific T cell responses demonstrated controversial findings suggesting that responses can be both affected or not by the presence of diabetes.
However, findings from this study demonstrated that elderly participants had impaired B cell response to the influenza vaccine and less B cell activation and reduced expression of both AID and the E47 transcription factor.
Other findings from the study showed that diabetic medication with anti-inflammatory action such as metformin used by type 2 diabetic patients would prevent inflammatory mediators such as negative TNF-α signaling in B cells. As a consequence of metformin treatment, although plasma TNF-α levels are not reduced in type 2 diabetics, there is decreased signaling through the TNF-α receptors resulting in decreased regulation of the B cell immune response. The reported reduced regulation suggests hyperactivation of the innate immune system in type 2 diabetics which would stimulate B cells. This hyperactivation in type 2 diabetics was noted by an increased stability for E47 mRNA and increased AID markers. The researchers of this study are currently still evaluating these molecular mechanisms and their relation to immune response. In addition, the authors are hypothesizing that all medications and possibly other products derived from gut bacteria, viruses and fungi (RNA, DNA, flagellin, peptidoglycan) could variably affect B cell response in type 2 diabetics.
Frasca, D, A Diaz, M Romero and et al. "Young and elderly patients with type 2 diabetes have optimal B cell responses to the seasonal influenza vaccine." Department of Microbiology and Immunology, University of Miami Miller, School of Medicine, Miami, FL 33101. Elsevier Ltd., 24 May 2013. Web. 5 Jun 2013.