Overlap Syndrome of ANCA-Associated Crescentic Glomerulonephritis, Autoimmune Hepatitis, and Rheumatoid Arthritis

Introduction: The most common renal histopathological in Rheumatoid Arthritis (RA) is Amyloidosis. Conflicting data exist about frequency of other types of glomerulonephritis in RA Case Description: 46 y.o. female with focal nodular hyperplasia and hemangioma of the liver, hypothyroidism admitted with constitutional symptoms, joint and abdominal pain. Laboratory data revealed abnormal LFTs (AST 336, ALT 498, Alk Phos 227, Albumin 3.0, TBili 5.6, DBili 4.6) and Creatinine 1.8 mg/dL (baseline 1.4). UA: 2+ protein, moderate Hb, 1 WBC, 22 RBC, UPCR 2.2 g/g and UACR 1.3 g/g. Urine microscopy showed granular casts. Serologies were positive for RF 27, Anti CCP >2776.8, ANCA 1:320, MPO>100, Smooth muscle Ab 46.0. C3 and C4 were normala. Sed rate 91 mm/h, C-Reactive protein 3.1 mg/dL. Hepatitis A, B, C, and HIV serology was negative. Simultaneous liver-kidney biopsy obtained. Renal biopsy showed a crescentic glomerulonephritis with fibrous (6/9 glom) and fibrocellular crescents (3/9 glom); reported as inactive associated with chronicity features (45% IFTA) and no activity (endocapillary proliferation, necrosis or thrombi). IF was nonspecific and EM did not show deposits. Liver biopsy showed severe acute hepatitis with extensive necrosis. Given inactive crescents and no activity, the decision was to treat autoimmune hepatitis with Prednisone and start Rituximab for Rheumatoid Arthritis with some collateral benefit on the kidney function. After weeks of treatment, she had improvement in LFTs and symptoms resolved. Kidney function did not significantly change after treatment. Discussion: This case displays a rare coexistence between three autoimmune entities including MPO ANCA related crescentic glomerulonephritis, Rheumatoid Arthritis and Autoimmune hepatitis. In majority of reported cases, ANCA vasculitis occurs a few years following the diagnosis of RA. Our case is unique for the simultaneous diagnosis of RA, ANCA vasculitis, and autoimmune hepatitis. The lack of improvement of renal despite Rituximab therapy is most likely related to the chronicity findings shown in her kidney biopsy, that was most likely damage from the ANCA related glomerulonephritis. RA can have different histopathologic renal manifestations and it is not limited to Amyloidosis. In the presence of significant proteinuria and hematuria, kidney biopsy needs to be considered in patients with RA.