Common variable immunodeficiency is one of the most frequent inborn errors of the immune system. The disease is characterized by impaired production of immunoglobulins, specific antibodies and immune system dysregulation.
The most common manifestations of dysregulation include autoimmune complications such as autoantibody-mediated autoimmune hemolytic anemia. On the other hand, hemolysis can also be caused by passively transmitted autoantibodies in immunoglobulin replacement therapy.
The aim of our 2year long prospective observational study was to monitor the prevalence and clinical significance of a wide range of autoantibodies, of which anti-TPO and anti-GAD occurred with the highest prevalence. However, the vast majority of patients developed neither type 1 diabetes mellitus nor autoimmune thyroiditis.
In addition, both autoantibodies were detected in significant amounts in solutions used for immunoglobulin substitution. Based on our results, we conclude that these are passively transmitted.
Thus, their assessment is of very limited importance in patients with T1DM or AIT on IRT and may lead to false positive results.