Comparison of clinical and immunological features and mortality in common variable immunodeficiency and agammaglobulinemia patients

Common Variable Immunodeficiency (CVID) and agammaglobulinemia are two of the main types of symptomatic primary antibody deficiencies. The pathogenic origins of these two diseases are different; agammaglobulinemia is a group of inherited disorders that usually are caused by mutations in the gene encoding Bruton Tyrosine Kinase (BTK) protein while CVID is a heterogeneous disorder mainly without monogenic cause. However, both diseases share a characteristic of frequent bacterial infections, a decline in serum immunoglobulin levels, and abnormality in antibody responses. The demographics and immunologic parameters, clinical manifestation, and mortality statistics from 297 patients with CVID and agammaglobulinemia followed up over 2 decades in the Children's Medical Center of Iran. Age at onset of symptom in agammaglobulinemia was earlier than CVID but the course of disease in CVID patients was longer than agammaglobulinemia patients. Pulmonary infections were the most prevalent clinical manifestations in both groups of patients. Lymphadenopathy, hepatomegaly, and splenomegaly were significantly higher in CVID patients than agammaglobulinemia patients and there was a significant association between these complications and mortality in CVID patients. Among 297 patients, 128 patients (88 CVID and 40 agammaglobulinemia) deceased. The predominant causes of death in CVID patients were infections, chronic lung disease, and malignancy while in agammaglobulinemia patients were infections and respiratory failure. Infections, especially respiratory infections were the most common complication and cause of death in both CVID and agammaglobulinemia groups and recent treatment advances even Immunoglobulin replacement cannot completely control these complications. Thus prompt recognition and specific management of these complications are worthwhile.