[Case of primary Sjögren's syndrome with hypereosinophilia and elevation of serum IgE: measurements of serum IL-4, IL-5 and the IgG subclass].

A 62-year-old man admitted to our hospital because of dry eyes and thirst. On admission, his bilateral parotid and submandibular glands were swelling. Laboratory data revealed severe eosinophilia (3309/microl), elevated serum IgE (1821IU/dl) and hypergammaglobulinemia (IgG 6049 mg/dl). Interstitial pneumonia and renal dysfunction were present. He was diagnosed with Sjögren's syndrome (SjS) according to the European criteria. After the initiation of the therapy with 30 mg of prednisolone, all abnormal findings including salivation ameliorated promptly. In the absence of any other obvious causes of eosinophilia and elevation of serum IgE, these findings might be associated with SjS itself. Moreover, both serum IL-5 and IgG4 levels were elevated in this patient, suggesting that Th2 type cytokines were dominant. Elevation of serum IgE and IgG4, and hypereosinophilia were likely to be reactive. To our knowledge, there have been no reports of these cytokines and of IgG subclass in such patients. We propose the existence of Th2-type-cytokine-dominant subtype of SjS.