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.

The arthritis-associated HLA-B*27:05 allele forms more cell surface B27 dimer and free heavy chain ligands for KIR3DL2 than HLA-B*27:09.

OBJECTIVES: HLA-B*27:05 is associated with AS whereas HLA-B*27:09 is not associated. We hypothesized that different interactions with KIR immune receptors could contribute to the difference in disease association between HLA-B*27:05 and HLAB*27:09. Thus, the objective of this study was to compare the formation of ß2m-free heavy chain (FHC) including B27 dimers (B272) by HLA-B*27:05 and HLA-B*27:09 and their binding to KIR immunoreceptors. METHODS: We studied the formation of HLA-B*27:05 and HLA-B*27:09 heterotrimers and FHC forms including dimers in vitro and in transfected cells. We investigated HLA-B*27:05 and HLA-B*27:09 binding to KIR3DL1, KIR3DL2 and LILRB2 by FACS staining with class I tetramers and by quantifying interactions with KIR3DL2CD3ε-reporter cells and KIR3DL2-expressing NK cells. We also measured KIR expression on peripheral blood NK and CD4 T cells from 18 HLA-B*27:05 AS patients, 8 HLA-B27 negative and 12 HLA-B*27:05+ and HLA-B*27:09+ healthy controls by FACS staining. RESULTS: HLA-B*27:09 formed less B272 and FHC than HLA-B*27:05. HLA-B*27:05-expressing cells stimulated KIR3DL2CD3ε-reporter T cells more effectively. Cells expressing HLA-B*27:05 promoted KIR3DL2+ NK cell survival more strongly than HLA-B*27:09. HLA-B*27:05 and HLA-B*27:09 dimer tetramers stained KIR3DL1, KIR3DL2 and LILRB2 equivalently. Increased proportions of NK and CD4 T cells expressed KIR3DL2 in HLA-B*27:05+ AS patients compared with HLA-B*27:05+, HLA-B*27:09+ and HLA-B27- healthy controls. CONCLUSION: Differences in the formation of FHC ligands for KIR3DL2 by HLA-B*27:05 and HLA-B*27:09 could contribute to the differential association of these alleles with AS.