INTRODUCTION: Primary immunodeficiencies (PIDs) are a group of diseases caused by genetic defects in the immune system.
X-linked Agammaglobulinemia (ALX) is a PID characterized by a mutation in Bruton’s tyrosine kinase (BTK), which causes a decrease or absence of B lymphocytes, and a decrease in peripheral blood immunoglobulins, predisposing to recurrent infections.
CLINICAL CASES:
Case 1: 11-year-old male, history of 3 male brothers who died from infections; from the age of 6 months he presented Recurrent Pneumonia, requiring hospitalization more than 20 times with intravenous antibiotics. Dosage of IgM and IgA not detectable, IgG 2.2 g/L; B lymphocyte 1%. Receive intravenous immunoglobulin (IVIG) with improvement of infections.
Case 2: A 15-year-old male, with a history of a maternal uncle who died in infancy apparently due to infections. The patient presented Gastrointestinal, Respiratory, and Urinary Infections since he was 3 months old. At 6 years, low dose IgM, IgA, IgG, B lymphocytes 0%; p.Gly419 mutation in axon 14 of the BTK gene, since then he has received IVIG every 28 days.
Case 3: 6-year-old male, with Otitis and Pneumonia that required hospitalization with multiple antibiotics since 6 months, low dosage of IgM, IgA, IgG, 3% B lymphocytes; p.Arg562Trp mutation in axon 17 of the BTK gene, receives IVIG every 28 days.
Case 4: 3-year-old male, from 6 months with Meningitis, Pneumonia, Otitis; requiring multiple hospitalizations, with 4 admissions to the pediatric intensive care unit; dosage of IgM 0.01 g/L, IgA 0.30 g/L, IgG 0.002 g/L; B lymphocyte 0%. Receive IVIG with improvement of infections.
DISCUSSION: It is important to suspect and reach a definitive diagnosis, start treatment early; isolation is not necessary, chronic or recurrent infections must be prevented with the application of adequate treatment and the indicated prophylaxis.