Scleroderma and IgG4-related disease

IgG4-related disease is a syndrome which involves lymphoplasmacytic infiltrates and soft tissue sclerosis, elevated serum IgG4 titer, and increased IgG4-positive plasma cells in a variety of tissues. Scleroderma is also characterized by fibrosis and lymphoplasmacytic infiltrates. To our knowledge, the presence of IgG4-positive cells has not been well characterized in scleroderma. A retrospective review of scleroderma and related disorders (calcinosis, raynaud's syndrome, esophageal dysmotility, sclerodactyly, telangiectasia (CREST) syndrome, progressive systemic sclerosis, morphea) was performed. Thirty-four cases of scleroderma and related disorders were identified; IgG4-positive and IgG-positive plasma cells were counted in 10 HPF and an IgG4:IgG ratio determined. A cutoff ratio of 0.3 was used to define significant elevation. Three of the scleroderma cases had IgG4:IgG greater than 0. Only 1 case had a significant elevation. Of the 3 cases with elevated ratio, IgG4-positive cells ranged from 2 to 64 (median = 14), with an IgG4:IgG ranging from 0.06 to 0.34 (median = 0.22). Similar results were produced with the other sclerosing disorders. These results suggest that scleroderma is not part of the IgG4-related disease spectrum.