Objective: To report an exceptional association between X-linked hyper-IgM syndrome and progressive multifocal leukoencephalopathy.
Design: Clinical, immunological, and histological analysis. Patient A 19-year-old male patient with X-linked hyper-IgM syndrome developed typical signs and symptoms of progressive multifocal leukoencephalopathy.
Results: The serum level of IgA was decreased; the serum level of IgM was slightly increased; and the serum level of IgG was normal as a result of monthly infusions of immunoglobulin. The expression of CD40 ligand on T cells was markedly reduced in the patient. Magnetic resonance imaging indicated confluent lesions involving the majority of the right hemisphere with a mass effect. The patient died after 6 weeks despite combined antiviral treatment.
Conclusion: Progressive multifocal leukoencephalopathy may follow a rapid course in patients with X-linked hyper-IgM syndrome because of global defects of cellular and B cell responses.