[Autoimmune diseases in patients with common variable immunodeficiency].

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency with an estimated prevalence of one in 10,000 to 50,000 inhabitants. This heterogeneous disease is characterized by decreased levels of serum immunoglobulins, a poor production of specific antibodies upon vaccination, and recurrent bacterial infections, particularly in the respiratory and gastrointestinal tract. A subgroup of patients is characterized by additional, and often predominant, manifestations of immune deregulation rather than pure immunodeficiency. Approximately, 30% of patients with CVID develop autoimmunity. Half of those complications can be attributed to autoimmune cytopenia, but also to other types of autoimmunity, such as organ-specific autoimmune diseases, often manifest as inflammatory disease, including inflammatory bowel disease, celiac disease, interstitial lung disease, some forms of arthritis, and vitiligo, among many others. New monogenic defects elucidate the immunopathological mechanism that causes the coincidence of immunodeficiency and autoimmunity. Autoimmune diseases have become the major clinical challenge in CVID, with new diagnostic tools, especially genetic ones, that improve the understanding of the different forms of immune deregulation.