Sjögren's syndrome with immune-complex tubulointerstitial renal disease

Abstract

Renal functional abnormalities and evidence of interstitial nephritis are common in Sjögren's syndrome, and it has been suggested that the interstitial changes may be on an immunologic basis. We report a patient with the sicca complex variety of Sjögren's syndrome who presented with renal functional insufficiency and intense interstitial nephritis. Focal tubular basement membrane (TBM) deposits were observed, and immunofluorescence showed focal TBM deposits of IgG and C3. Glomeruli contained no deposits. Therapy with prednisone and cyclophosphamide was associated with marked clinical improvement and regression of tissue leukocyte infiltration. We propose local or in situ formation of immune complexes, as in the rabbit model of autologous immune-complex interstitial nephritis, and suggest that this mechanism may be operative in some patients with Sjögren's syndrome and tubulointerstitial renal disease. Immunosuppressive therapy may have helped to preserve renal function.