[A retrospective study of one case of X-linked agammaglobulinemia]

To investigate the clinical manifestations, diagnostic methods and treatment of X-linked agammaglobulinemia (XLA).

Flow cytometric analysis of the peripheral monocytes using the anti-BTK antibody was used to characterize the expression of BTK in a 21 year old male patient and his mother. The patient suffered from frequent pneumonia, and was found to be complicated with lymphocytopenia in the B cell populations, hypogammaglobulinemia (IgG 1.38 g/L, IgA 0.25 g/L, IgM 0.17 g/L) and angiotelectasis (which had not been reported in XLA patients). Sequencing of the BTK cDNA obtained from the peripheral monocytes of the patient and his mother was performed to confirm the genetic defect.

The BTK expressions in peripheral monocytes of the patient and his mother were 96.9% and 97.8% respectively. Sequencing of the BTK gene revealed a missense mutation of R525Q in exon 16, and his mother was confirmed to be an XLA carrier. The patient was treated with immunoglobulin replacement therapy (2 g/kg). One month later, the serum IgG level of the patient was elevated to 5.79 g/L, and the clinical symptoms (included angiotelectasis), lung function and the CT scan results significantly improved.

Genetic diagnosis was made for one Chinese XLA adult patient complicated with angiotelectasis. This case suggests that some XLA cases may present angiotelectasis. High dose intravenous immunoglobulin given at 2 g/kg may be of efficacy in severe XLA cases. More attention should be paid to the disease in China.