Concurrent Renal Sarcoidosis and Lupus nephritis

V.S. Venkataseshan, Department of Pathology Barnert Hospital, 680 Broadway, Paterson, NJ 07514 (USA) Dear Sir, Sarcoidosis and systemic lupus erythema-tosus (SLE) are both multisystemic, distinctive disorders of unknown etiology. Sarcoidosis is characterized by an accumulation of monocytemacrophages to form noncaseat-ing granulomata. In SLE, tissue manifestations are associated mainly with complement activation by autoantibodies and immune complexes, and to some extent by cell-mediated immune complexes, and to some extent by cell-mediated immune mechanisms. Renal involvement may occur in both diseases but is more common in SLE. The coexistence of sarcoidosis and SLE is uncommon [1-4] and the simultaneous involvement of the kidney in this situation is rare. To our knowledge, this is only the second case reported where the kidney is involved in such patients, and the first case was not biopsied [2]. A 43-year-old female presented initially with iridocyclitis, which improved with topical prednisone. A year later, she developed cough with bilateral interstitial lung infiltrates showing sarcoid granulomata and was treated successfully with steroids. Ten months later, she developed recurrent lung disease, fever, generalized arthralgia hilar and nontender inguinal lymphadenopathy. Laboratory studies were as follows: urine protein 0.8 g/24 h with normal sediment, serum BUN 4.6 mmol/l (15 mg/dl), creatinine 53 mmol/l (0.6 mg/dl), calcium 1.9 mmol/l (7.8 mg/dl), phosphorus 0.90 mmol/l (2.8 mg/dl), albumin 27 g/l (2.7 g/dl), and polyclonal globulins 38 g/l (3.8 g/dl). ANA was 1:320 with a smooth pattern, and anti-double-stranded (ds) DNA was 28% (normal 0-4%). The rheumatoid factor was positive, angio-tensin-converting enzyme (ACE) was 115 U/l (normal 852), C3 9.8 g/l (98 mg/dl) and C4 1.3 g/l (13 mg/dl; normal 15-45). A 3-day pulse dose of intravenous methylpredniso-lone produced remission. By percutaneous renal biopsy, the glome-ruli showed mild to moderate mesangial widening, thickened capillary walls and small areas of capillary thrombi and necrosis (fig. 1). Scattered small interstitial, noncaseating granulomata were noted (fig. 2). Immunofluores-cence microscopy (IF) revealed diffuse, granular 3 + IgM, 2 + IgG, 3 + Clq and 1 + Q deposits in the glomerular mesangium and capillary walls. Subepithelial and mesangial electron-dense deposits were found (fig. 3a, b). A diagnosis of membranous and focal glomerulonephritis along with interstitial sarcoid granulomata was made.