Hypogammaglobulinemia: a diagnosis that must not be overlooked.

Humoral immunological defects are frequent and important causes of hypogammaglobulinemia, leading to recurrent infections, autoimmunity, allergies, and neoplasias. Usually, its onset occurs in childhood or during the second and third decades of life; however, the diagnosis is made, on average, 6 to 7 years afterwards. As a consequence, antibody defects can lead to sequelae. Here we describe the clinical-laboratory characteristics, treatment, and prognoses of patients with hypogammaglobulinemia. An observational, cross-sectional, and retrospective study of patients attending the recently established outpatient group of Clinical Immunology between 2013 and 2018 was carried out. Patients with IgG levels below 2 standard deviations from the mean values for the age and/or impaired antibody response were included. Eight patients (3 F and 5 M; median age=41 years (16-65), average symptom onset at 25 years (1-59), and time to diagnosis of 10 years were included. The main infections were: sinusitis in 7/8, pneumonia in 6/8, otitis in 2/8, tonsillitis and diarrhea in 2/8, and diarrhea in 2/8 patients. Hypothyroidism was identified in 4/8 (50%) patients. Rhinitis was found in 7/8 (87.5%) and asthma in 3/8 (37.5%) patients. The tomographic findings were consolidations, atelectasis, emphysema, ground glass opacity, budding tree, bronchial thickening, and bronchiectasis. Immunoglobulin reposition was used between 466 and 600 mg/kg monthly (514.3 mg·kg-1·dose-1). Prophylactic antibiotic therapy was included in 7/8 (87.5%) patients. Airway manifestations prevailed in patients with hypogammaglobulinemia. There is a need for educational work to reduce the time of diagnosis and initiation of treatment, avoiding sequelae.