Clinical features of immunoglobulin G4-related disease with central nervous system involvement: an analysis of 15 cases.

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease that affects various organs of the body. The aim of this study is to elucidate the clinical characteristics of IgG4-RD with central nervous system (CNS) involvement.Among 589 patients with IgG4-RD in a prospective single-centre cohort study in Peking Union Medical College Hospital, 15 patients had CNS involvement. The clinical data including demographic features, symptoms, involved organs, laboratory findings, radiological results, pathology, treatment and outcome were analysed.Seventeen patients, including nine men and six women, had IgG4-related neuropathy, with an average age of 49.8±12.3 years. IgG4 related hypophysitis was the most common manifestation, accounting for 40% (6/15) of cases, followed by hypertrophic cranial pachymeningitis (n=4), hypertrophic spinal pachymeningitis (n=2), intracranial mass (n=2), cavernous sinus and orbital disease (n=1). Most patients had multi-organ involvement, with the most common extra-CNS manifestations were Mikulicz disease (MD) and lymphadenitis in 5 (33.3%) cases. Serum IgG4 levels were elevated in 12/15(80%) patients and the median value was 438.5 (104, 2250)mg/dL. Fourteen cases underwent biopsy, of which tissue was taken directly from CNS lesions in 4 cases. All patients received treatment with glucocorticoids (GCs) combined with immunosuppressants, including cyclophosphamide, tacrolimus, mycophenolate mofetil, and tripterygium glycosides. Complete remission was achieved in 3/15 (20.0%) patients, and 11/15 cases (73.3%) achieved partial remission.IgG4-related CNS involvement is a rare and distinct entity of IgG4-RD. Treatment with corticosteroids combined with immunosuppressive agents yielded favourable responses.