Anti-ficolin-2 autoantibodies may represent a biomarker for renal manifestations in patients with active systemic lupus erythematosus (SLE), according to the results of a recent comparative cohort study (ClinicalTrials.gov identifier: NCT03063281) published in Arthritis Care & Research (Hoboken).
The cohort comprised a total of 165 patients with SLE and 48 control subjects. Patients with SLE were divided into a “low disease activity” (SLE Disease Activity Index [SLEDAI] score ≤4, n=88) and a “high disease activity” (SLEDAI score >4, n=77) group. Active lupus nephritis was confirmed through kidney biopsy. Anti-ficolin-2 antibodies were detected using enzyme-linked immunosorbent assays.
Titers of anti-ficolin-2 antibodies were significantly higher in the serum of patients with SLE compared with healthy control subjects (median score, 74 vs 61 arbitrary units [AU]; P =.0403). With a cutoff value of 95 AU, anti-ficolin-2 antibodies were detected as positive in 37% (61 of 165) of patients with SLE.
Anti-ficolin-2 antibodies were positively identified in 44% (34 of 77) of patients with SLE in the “high disease activity” group, and in 30% (26 of 88) of the patients in the “low disease activity” group, and autoantibody titer values were higher in patients with high vs low disease activity (median 84 AU vs 68 AU; P =.0123). Anti-ficolin-2 antibodies were detected in 86% (31 of 36) of patients with SLE and active lupus nephritis, and their titer values were higher in these patients compared with patients with active disease without renal involvement (median 152 AU vs 71 AU, respectively; P <.0005). The presence of anti-ficolin-2 antibodies was associated with renal involvement (P =.006).
The investigators concluded that, even if additional longitudinal studies are warranted to validate the diagnostic and prognostic role of this new SLE parameter, this study supports the utility of anti-ficolin-2 as an additional serologic biomarker for the diagnosis of active SLE with renal manifestations.
Colliard S, Jourde-Chiche N, Clavarino G, et al. Autoantibodies targeting ficolin-2 in systemic lupus erythematosus patients with active nephritis [published online October 17, 2017].
Arthritis Care Res (Hoboken). doi: 10.1002/acr.23449