Resolution of Primary Immune Defect in 22q11.2 Deletion Syndrome.

PURPOSE: Patients with 22q11.2 deletion syndrome have a variable decrease in immunological parameters, especially regarding T cell counts. The aim of this study was to investigate immunological change over time and factors associated with immunological recovery among patients with 22q11.2 deletion syndrome.

METHODS

Patients with 22q11.2 deletion syndrome diagnosed by fluorescence in situ hybridization (FISH) were studied. Immunological parameters were evaluated every 6 months until patients returned to normal. Infection and vaccination histories were recorded and analyzed, and Kaplan-Meier survival curves were plotted to describe resolution of immunodeficiency.

RESULTS

Forty-nine patients with an age range of 4 to 222 months were included. Twenty-five (51%) patients were female. In hypocalcemia, the odds ratio for CD4 lymphopenia was 17.03 (95%CI 1.82-159.23; p value = 0.01). Thirty patients (61.2%) exhibited decreased CD4+ T cell numbers, which returned to normal level in 18 (60%) patients. Median age of CD4+ T cell resolution was 2.5 years. T cell functions were abnormal in three patients. T cell functions returned to normal in all patients at a median age of 1.1 years. Six patients (13.5%) had abnormal serum immunoglobulin levels, with levels improving in four patients at 1.4 years of age. The most common infection was pneumonia (69.4%). BCG vaccination was administered in 47 of 49 patients at birth. Among 32 patients who had T cell defect, one patient developed BCGitis and one developed disseminated BCG.

CONCLUSION

Immunodeficiencies identified among patients with 22q11.2 deletion syndrome were T cell defect (65.3%) and decreased immunoglobulin levels (12.2%). Median age of CD4 resolution was 2.5 years.