Primary Immunodeficiencies in Brazilian patients younger than five years old

Abstract

RATIONALE: Primary Immunodeficiencies (PID) represent a heterogeneous group of diseases whose prognosis depends on early diagnosis and treatment. In most PID series so far reported, the distribution for age groups in the first years of life has not been emphasized. The aim of this study was to describe the experience of a pediatric Brazilian reference center for PID in children younger than 5 years.METHODS: Evaluation of 251 patients with well characterized PID distributed into the eight PID groups according to the latest IUIS classification (2009). Patients were allocated into 2 age groups: Group 1 (<2 years-old) and Group 2 (2-5 years-old).RESULTS: In Group 1 (n=118, 74% males), combined T and B-cell immunodeficiencies were the most frequent type (25%), followed by phagocyte defects (21%), antibody deficiencies (16%), diseases of immune dysregulation (14%), other well-defined immunodeficiency syndromes (13%), being the groups of autoinflammatory syndromes (5%), innate immunity deficiencies (2%), and complement deficiencies (4%) the less common. The analysis of Group 2 (n=133, 67% males) demonstrated antibody deficiencies as the predominant group (44%), followed by well-defined syndromes (17%), phagocyte defects (15%), complement deficiencies (9%), diseases of immune dysregulation (8%), combined T and B-cell deficiencies (4%), innate immunity deficiencies (2%) and autoinflammatory syndromes (1%). The authors point out the predominance of severe combined immunodeficiencies among the infants.CONCLUSION: The knowledge of the unique PID distribution in specific age groups may allow development of surveillance programs as well as earlier detection, leading to more efficacious treatment and better prognosis. RATIONALE: Primary Immunodeficiencies (PID) represent a heterogeneous group of diseases whose prognosis depends on early diagnosis and treatment. In most PID series so far reported, the distribution for age groups in the first years of life has not been emphasized. The aim of this study was to describe the experience of a pediatric Brazilian reference center for PID in children younger than 5 years. METHODS: Evaluation of 251 patients with well characterized PID distributed into the eight PID groups according to the latest IUIS classification (2009). Patients were allocated into 2 age groups: Group 1 (<2 years-old) and Group 2 (2-5 years-old). RESULTS: In Group 1 (n=118, 74% males), combined T and B-cell immunodeficiencies were the most frequent type (25%), followed by phagocyte defects (21%), antibody deficiencies (16%), diseases of immune dysregulation (14%), other well-defined immunodeficiency syndromes (13%), being the groups of autoinflammatory syndromes (5%), innate immunity deficiencies (2%), and complement deficiencies (4%) the less common. The analysis of Group 2 (n=133, 67% males) demonstrated antibody deficiencies as the predominant group (44%), followed by well-defined syndromes (17%), phagocyte defects (15%), complement deficiencies (9%), diseases of immune dysregulation (8%), combined T and B-cell deficiencies (4%), innate immunity deficiencies (2%) and autoinflammatory syndromes (1%). The authors point out the predominance of severe combined immunodeficiencies among the infants. CONCLUSION: The knowledge of the unique PID distribution in specific age groups may allow development of surveillance programs as well as earlier detection, leading to more efficacious treatment and better prognosis.