Elevated serum immunoglobulin A levels in patients with Clostridium difficile infection are associated with mortality

The current research investigated immunoglobulin A levels in serum of patients with Clostridium difficile infection. Our main aim was to test whether immunoglobulin A (IgA) levels at the early stage of infection can predict disease severity of C. difficile infection. Fifty-four patients were enrolled in the study. Stool samples were collected and analyzed by PCR for detection of C. difficile. IgA levels were measured in serum samples that were collected from each patient immediately after receiving a positive PCR result. Additionally, data concerning epidemiologic and clinical characteristics of the patients was retrospectively collected from the medical records. Serum IgA levels were not associated with the severity of C. difficile infection. However, a positive correlation between IgA levels and mortality during hospitalization was found. Additionally, IgA levels correlated with C-reactive protein and white blood cell levels. Although we did not find a correlation between IgA levels and C. difficile infection severity, we could associate IgA levels with the severity of general immune response and to complications of the infection, i.e. mortality. We think that this could represent a compensatory mechanism to the damage caused by C. difficile. Considering serum IgA anti-inflammatory functions, it is possible the increase in IgA levels aimed to suppress the more intense inflammatory response in patients who died during hospitalization.