Injection drug users (IDUs) are at a greater risk of contracting co-morbidities like HIV, hepatitis, and other blood-contracted diseases. However, it’s possible that the act of injection drug use itself may be altering the immune profile of IDUs, which may make them more susceptible to these infections.
New research from Pipenbrink et al. uses a flow cytometry approach to determine whether the immune profiles of IDUs are different than non-IDUs. The research group found that IDUs had a “significant, 2-fold increase in total B cells” compared to non-IDUs.
With regard to immunoglobulins, the research group found that plasma total IgG titers were similar between the groups, but “IDUs had significantly higher IgG3 and IgG4.” The increased levels of IgG3 and IgG4 indicates that IDUs may suffer from chronic B cell activation. Of note was the IgM levels in IDUs. While total IgM was decreased in IDUs relative to the control group, a greater level of HIV Envelope-specific IgM was found, which indicates a greater exposure to HIV in IDUs.
The wide changes in the humoral profile of IDUs mentioned above indicate that IDUs suffer from increased systemic inflammation. This dysregulation may be a cause for a reduced ability of the immune system to respond to infection, and may be a cause for the higher rates of co-morbidities seen in IDU populations.