Rheumatologic Manifestations of the Primary Immunodeficiency Syndromes
1. Hypogammaglobulinemia occurs in over 80% of patients with a primary immunodeficiency (PID), and the most common disease-defining features of PID are recurrent infection and tissue-threatening autoimmunity.
2. Mutations in certain genes can lead to immune dysregulation causing both immunodeficiency and autoimmunity.
3. Common variable immunodeficiency (CVID) may present in early adulthood as large and medium joint inflammatory polyarthritis; significant hypogammaglobulinemia may not present until later.
4. Early complement protein (C1, C4, and C2) deficiencies are associated with autoimmune diseases, whereas late (C5 to C8) deficiencies are associated with infections with Neisseria.
5. Understanding the genetic basis of PID syndromes may lead to a better understanding of potential infection- and autoimmune-related adverse events when disease-modifying antirheumatic drugs (DMARDs) or biologics are used to treat rheumatic or oncologic disease.
