Background: We examined four patients who exhibited both idiopathic retinal vasculitis and elevated serum IgD levels. Uveitis caused by Behçet's disease is also associated with high levels of serum IgD. Therefore, the clinical features of these patients were investigated and the possible relationship between retinal vasculitis and elevated serum IgD was examined after undertaking a study of increased IgD levels in patients diagnosed with uveitis.
Methods: The study population was composed of 110 patients: 49 with Behçet's disease, 15 with sarcoidosis, 10 with Vogt-Koyanagi-Harada disease, and 36 with other forms of uveitis. IgD measurements were performed using modifications of the latex photometric immunoassay. Surface IgD (sIgD) expression in peripheral lymphocytes was determined by immunofluorescence, and the correlation between serum IgD levels and the percentage of sIgD-positive cells was examined.
Results: Twelve of the 110 patients had an elevated serum IgD. Eight of the 12 had Behçet's disease, and 4 were diagnosed with idiopathic retinal vasculitis. These 4 patients were HLA-A24+ females whose ages ranged from 8 to 25 years. A linear correlation between the serum IgD levels and the percentage of sIgD-positive cells was found.
Conclusion: Hyperimmunoglobulinemia D state was found in Behçet's disease and idiopathic retinal vasculitis. These diseases may represent a new clinical entity characterized by signs of retinal vasculitis and hyperimmunoglobulinemia D that results from abnormal B cell activation and immune complex-mediated responses.