Hyper-immunoglobulin A in the hyperimmunoglobulinemia D syndrome

The hyperimmunoglobulinemia D syndrome (HIDS) is an autosomal recessive dis order characterized by recurrent febrile attacks with abdominal, articular, and skin manifestations. Apart from elevated immunoglobulin D (IgD) levels (>100 IU/ml), there are high IgA levels in the majority of cases. Mutation s in the gene encoding mevalonate kinase constitute the molecular defect in HIDS, The cause of elevated IgA concentrations in HIDS patients remains to be elucidated. We studied the hyper-IgA response in serum of a group of HI DS patients. Elevated IgA concentrations result from increased IgA1 concent rations. IgA and IgA1 concentrations correlated significantly with IgD conc entrations, and levels of IgA polymers were significantly higher than the l evels in healthy donors. These results indicate a continuous, presumably sy stemic, stimulation of IgA in HIDS patients.