Development and validation of a prognostic nomogram for IgA nephropathy

// Jian Liu 1 * , Shuwei Duan 1, * , Pu Chen 1 , Guangyan Cai 1 , Yong Wang 1 , Li Tang 1 , Shuwen Liu 1 , Jianhui Zhou 1 , Di Wu 1 , Wanjun Shen 1 , Xiangmei Chen 1 and Jie Wu 1 1 Department of Nephrology, Chinese People’s Liberation Army (PLA) General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing Key Laboratory of Kidney Diseases, Beijing, China * These authors have contributed equally to this work Correspondence to: Xiangmei Chen, email: xmchen301@126.com Jie Wu, email: wujie301@126.com Keywords: nomogram, IgA nephropathy, prognosis, pathology, risk Received: July 06, 2017     Accepted: August 27, 2017     Published: October 10, 2017 ABSTRACT IgA nephropathy (IgAN) shows strong heterogeneity between individuals. IgAN prognosis is associated with pathological lesions and clinical indicators. However, simple tools for evaluating the clinical prognosis remain inadequate. Our objective was to develop an intuitive estimation tool for predicting the IgAN prognosis. 349 patients with IgAN at The Chinese People’s Liberation Army General Hospital were retrospectively analyzed from data between 2000 and 2006. A nomogram was developed using COX regression coefficients to predict decline of estimate Glomerular filtration rate (eGFR) ≥ 50% and end-stage renal disease (ESRD). The discriminative ability and predictive accuracy of the nomogram was determined via concordance index (C-index) and calibration curve. The results were verified in an independent validation cohort. In the derivation cohort, the nomogram was developed using mesangial hypercellularity, tubular atrophy/interstitial fibrosis, average proteinuria (A-P), and average mean arterial pressure (A-MAP) during hospitalization. The C-index of the nomogram was 0.88 (95% CI, 0.80 to 0.96). The calibration curve showed good agreement between prediction and actual observation. Furthermore, the nomogram demonstrated good discrimination (C-index = 0.87, 95% CI 0.78 to 0.95) and calibration in the validation cohort. The nomogram could predict the prognosis of IgAN effectively and intuitively.