IL-17 and IL-23 in lupus nephritis - association to histopathology and response to treatment

• Background: Recent studies indicate a central role for the IL-23/IL-17 axis in the pathogenesis of lupus nephritis (LN) but the importance in the context of treatment outcome is unknown. We studied various cytokines, including the IL-23/IL-17 axis, in association to histopathology and response to therapy. Methods: Fifty-two patients with active LN were included. Renal biopsies were performed at baseline and after immunosuppressive treatment. Serum levels of TNF-alpha, IFN-gamma, IL-6, IL-10, IL-17, IL-23 and TGF-beta were analysed at both biopsy occasions and in 13 healthy controls. IL-17 expression in renal tissue was assessed by immunohistochemistry. Biopsies were evaluated regarding WHO-classification and renal disease activity was estimated using the BILAG-index. Improvement of 2 grades in renal BILAG was regarded complete response, and 1 grade partial response. Results: At baseline, all patients had high disease activity (BILAG A/B). Baseline levels of IL-6, IL-10, IL-17, IL-23 (p < 0.001) and IFN-gamma (p = 0.03) were increased in patients vs. controls. In contrast, TGF-beta was lower in patients compared to controls (p < 0.001). Baseline levels of IL-17 were higher in patients with persisting active nephritis (WHO III, IV, V) after treatment, i.e. a poor histological response, vs. WHO I-II (p < 0.03). At follow-up, IL-23 were higher in BILAG-non-responders vs. responders (p < 0.05). Immunostaining of renal tissue revealed IL-17 expression in inflammatory infiltrates. Conclusions: High baseline IL-17 predicted an unfavourable histopathological response, and BILAG-non-responders had high IL-23, indicating that that a subset of LN-patients has a Th-17 phenotype that may influence response to treatment and could be evaluated as a biomarker for poor therapeutic response.

Ämnesord

Medical and Health Sciences  (hsv)

Basic Medicine  (hsv)

Immunology in the medical area  (hsv)

Medicin och hälsovetenskap  (hsv)

Medicinska grundvetenskaper  (hsv)

Immunologi inom det medicinska området  (hsv)