Major low‐energy trauma results in non‐specific immunoglobulin generation without evidence for specific autoantibody production: A prospective cohort study.

Cellular debris resulting from large trauma might overwhelm the scavenger mechanisms and lead to autoimmune reactions. We analysed whether a major well‐defined trauma in humans induces laboratory signs of transient autoimmunity in the months after the insult. We included 50 patients with pertrochanteric femur fracture undergoing intramedullary nail osteosynthesis in a prospective cohort study and followed them at 3–4 days, 6 weeks, 12 weeks and 12 months postoperatively. By standard techniques, we assessed levels of total immunoglobulins, anti‐nuclear antibodies (ANA), anti‐cardiolipin antibodies, anti‐dsDNA antibodies and anti‐C1q antibodies, as well as antibodies against cytomegalovirus (CMV) as a control. Blood leukocyte differential and lymphocyte subpopulations were determined at baseline and in the first two postoperative samples. The mean age of the patients reached 80.1 years, and 23 (46%) completed all visits. Serum concentrations of total IgG, IgM and IgA increased at all follow‐up time points. The ANA fluorescence light intensity units increased at 12 weeks and 12 months postoperatively (p < 0.0001), but the proportion of ANA‐positive patients did not change (35%). The values of anti‐C1q mildly increased at all follow‐up visits, but not the ratio to total IgG. Anti‐dsDNA remained negative in all patients, and anti‐cardiolipin IgG/IgM antibodies did not change. Anti‐CMV IgG antibodies increased significantly at all follow‐up visits, without change in the ratio to total IgG. Flow cytometry showed an increased proportion of B‐cells 3–4 days postoperatively. In conclusion, major musculoskeletal trauma in elderly patients induces a generalized non‐specific increase in immunoglobulin production without laboratory signs for enhanced systemic autoimmunity. [ABSTRACT FROM AUTHOR]