Study of the agreement between clinical opinion of rheumatologists regarding the need for immunosuppression and the result of renal biopsy in adult patients with lupus nephritis

Abstract

Abstract Introduction In patients with lupus nephritis it is necessary to define the need for immunosuppressive therapy according to histological class observed in renal biopsy. Objective To evaluate the agreement between the opinions of six independent clinical rheumatologists regarding the need for immunosuppression and the result of renal biopsy in patients with lupus nephritis. Materials and methods A cross-sectional study on the agreement between a diagnostic test in adult patients with systemic lupus erythematosus. Each rheumatologist predicted the outcome of the biopsy. In order to evaluate the agreement, a dichotomous qualitative outcome was defined and was considered zero if it was not necessary to add a cytotoxic (classes I, II and VI), and otherwise was (classes III, IV, V or combinations). The percentage agreement and kappa statistics with a confidence interval of 95% was measured. Results Information was collected on 34 patients, with a total of 204 predictions made by 6 rheumatology interns. Rheumatologists were correct in their clinical impression in 180 cases (88.2% concordance rate, overall kappa of 0.62 (95% CI = 0.48–0.76)). Of the 204 scenarios generated, 162 corresponded to proliferative forms of lupus nephritis, for which the rheumatologists anticipated the need for immunosuppression in 153 and failed to treat in 9 cases (5.5%, or about 1 in 18). Conclusions The clinical opinion of rheumatologist is quite successful in defining the need for immunosuppression. In general, expert opinion could eventually be offered as an alternative choice to renal biopsy for the patient.