Primary immunodeficiency in south China: clinical features and a genetic subanalysis of 138 children

We analyzed the clinical features of 138 patients with primary immunodeficiency (PID) and performed genetic testing on a subset of patients in order to complete gaps in research on PID in South China and thus improve pediatricians' ability to recognize and diagnose PID.

We performed a retrospective analysis based on the medical records of PID patients hospitalized in our institution between May 1999 and June 2012. Gene sequencing was performed in 59 cases.

Children with PID usually present with fever and repeated infections that generally affect the respiratory and digestive tracts. Growth retardation is observed in some cases. Of the 138 patients, 113 were boys, median age at onset was 5 months (range, 0-119 months), and age at diagnosis was 10 months (2-159 months). A family history of repeated infection or death of family members in infancy because of recurrent infections was recorded in 20 cases (14.49%). Antibody defects were detected in 48 cases (34.78%), combined immunodeficiency disease in 45 cases (32.61%), and other well-defined immunodeficiency syndromes in 45 cases (32.61%). Of the 59 patients from the genetic subanalysis, 24 (15.94%) had a genetic mutation (x-linked agammaglobulinemia, 8 cases; severe combined immunodeficiency, 8 cases; hyperimmunoglobulin M syndrome, 3 cases; hyperimmunoglobulin E syndrome, 3 cases; chronic granulomatous disease, 2 cases). We detected 4 novel mutations. No relevant mutations were found in the remaining 35 cases.After treatment with intravenous immunoglobulin and anti-infectious agents, 16 patients died in hospital, and 5 cases died after discontinuing treatment (mortality, 15.22%).

In recent years, the number of patients with PID has risen gradually in South China. Genetic testing can confirm diagnosis. Since PID seriously affects children's quality of life, it is important to diagnose, treat, and intervene early.We hope our clinical and genetic analyses of children with PID can provide diagnostic guidance for clinicians.