Anti-neutrophil cytoplasmic antibody-associated pauci-immune crescentic glomerulonephritis complicating Sjögren's syndrome

Sj?gren's syndrome is a chronic autoimmune disease, characterized by specific autoimmune antibodies anti-Ro and anti-La, and it can involve multiple organs, such as the kidneys, lungs, muscles, and nervous system. The most common renal complication of Sj?gren's syndrome is tubulointerstitial nephritis, and glomerulonephritis is relatively uncommon. We report the case of an 86-year-old man presenting with recurrent fever, poor appetite, decreased salivary secretion, and body weight loss. Laboratory investigation revealed that serum creatinine was 4.2 mg/dL, proteinuria was 3+, and there was microscopic hematuria. Positive perinuclear anti-neutrophil cytoplasmic antibody, anti-Ro, and anti-La antibodies were detected. Renal biopsy showed crescentic glomerulonephritis with scanty immune complex deposition. The patient was diagnosed with primary Sj?gren's syndrome complicated with rapidly progressive glomerulonephritis with positive anti-neutrophil cytoplasmic antibody. Unlike the patients of other case reports, our patient's renal function did not recover after immunosuppressant treatment, and he finally received long-term hemodialysis. Pauci-immune glomerulonephritis is a rare renal complication of Sj?gren's syndrome, and progress to renal failure in such patients is possible. ? 2011 Elsevier & Formosan Medical Association.