Biologics-induced autoimmune renal disorders in chronic inflammatory rheumatic diseases: systematic literature review and analysis of a monocentric cohort.

The use of biologic drugs has been linked with the paradoxical development of systemic and organ specific autoimmune processes. The aim of this study was to describe the features of biologics-induced autoimmune renal disorders (AIRD) through a systematic review and a cohort study of 707 adult patients affected with Rheumatoid Arthritis (RA), Ankylosing Spondylitis (SA) and Psoriatic Arthritis (PsA). The literature search identified 2687 articles of which 21 were considered relevant for the present study, accounting for 26 case reports. The cohort analysis retrieved 3 cases. According to clinical manifestations and kidney histology the identified AIRD cases were classified as: a) glomerulonephritis associated with systemic vasculitis (GNSV), b) glomerulonephritis in lupus-like syndrome (GNLS), c) isolated autoimmune renal disorders (IARD). Twenty-two out of 29 cases with AIRD were reported in patients affected by RA, 5 in AS and 2 in PsA. The biologic drug most frequently associated with development of AIRD was Etanercept (15 cases, 51.7%), followed by Adalimumab (9 cases, 31.0%) and Infliximab (3 cases, 10.3%) while Tocilizumab and Abatacept were reported in 1 case (3.4%) for each. Thirteen out of 29 (44.8%) cases were classified as affected by IARD, 12 (41.3%) as GNSV and 4 (13.9%) as GNLS. Worse prognosis was associated with GNSV and lack of biologic withdrawal. Although rare, AIRD may be life-threatening and may lead to renal failure and death. If AIRD occurs, biologic drugs must be stopped and patient should be treated according to clinical manifestations and kidney biopsy findings.