Methods: Venous blood samples were collected from 64 children in Pediatric Hospital Professor Heriberto Ferreira Bezerra (HOSPED) - Federal University of Rio Grande do Norte (UFRN), Brazil. The laboratory investigation included measurement of serum IgG, IgM and IgA levels by imunoturbidimetry and the B lymphocyte quantification by flow cytometry with monoclonal anti-CD19+ for the cases that presented decreased of the serum immunoglobulins.
Results: Among the 64 children included, 33 (51,6%) were male and 31 (48,4%) were female. The children age ranged from 2 months to 15 years old. According to age, 36 (56%) children were aged 0-5 years; 11 (17%) children were aged 5 years and 1 month to 10 years; 10 (16%) children were aged 10 years and 1 month to 13 years and 11 months and 7 (11%) children were aged 14 years to 15 years. Immunoglobulin concentration below age-appropriate reference values was observed for IgG in 7 (11%) children; for IgM in 3 (4,7%) children and for IgA in 3 (4,7%) children. B lymphocytes were absent in 3 (4,7%) children. The superior respiratory tract infections were the most prevalent in this population.
Conclusions: B-cell disorders are the most common type of immunodeficiencies and they are characterized by an increased susceptibility to respiratory tract infections. In this study, 3 patients received the clinical and laboratory diagnostic of X-linked agammaglobulinemia.