Clinical implication of the circumferential crescents lesions in immunoglobulin A nephropathy: a single-center study of Han Chinese population

Crescent calculator: A webtool enabling objective decision-making for assessment of IgA nephropathy immune activity throughout the disease course

IgA nephropathy (IgAN) is an immune-mediated glomerulonephritis, posing a challenge for the long-term management. It is crucial to monitor the disease's activity over the disease course. Crescent lesions have been known as an active lesion associated with immune activity. We aimed to develop the Crescent Calculator to aid clinicians in making timely and well-informed decisions throughout the long-term disease course, such as renal biopsies and immunosuppressive therapy. 1,761 patients with biopsy-proven IgAN were recruited from four medical centers in Zhejiang Province, China. 16.9% presented crescent lesions. UPCR, URBC, eGFR and C4 were independently associated with the crescent lesions. By incorporating these variables, the Crescent Calculator was constructed to estimate the likelihood of crescent lesions. The predictor achieved AUC values of over 0.82 in two independent testing datasets. In addition, to fulfill varied clinical needs, multiple classification modes were established. The Crescent Calculator was developed to estimate the risk of crescent lesions for patients with IgAN, assisting clinicians in making timely, objective, and well-informed decisions regarding the need for renal biopsies and more appropriate use of immunosuppressive therapy in patients with IgAN.

Nomogram for the prediction of crescent formation in IgA nephropathy patients: a retrospective study

BACKGROUND

The 2017 Oxford classification of immunoglobulin A nephropathy (IgAN) recently reported that crescents could predict a worse renal outcome. Early prediction of crescent formation can help physicians determine the appropriate intervention, and thus, improve the outcomes. Therefore, we aimed to establish a nomogram model for the prediction of crescent formation in IgA nephropathy patients.

METHODS

We retrospectively analyzed 200 cases of biopsy-proven IgAN patients. Least absolute shrinkage and selection operator(LASSO) regression and multivariate logistic regression was applied to screen for influencing factors of crescent formation in IgAN patients. The performance of the proposed nomogram was evaluated based on Harrell's concordance index (C-index), calibration plot, and decision curve analysis.

RESULTS

Multivariate logistic analysis showed that urinary protein ≥ 1 g (OR = 3.129, 95%CI = 1.454-6.732), urinary red blood cell (URBC) counts ≥ 30/ul (OR = 3.190, 95%CI = 1.590-6.402), mALBU ≥ 1500 mg/L(OR = 2.330, 95%CI = 1.008-5.386), eGFR < 60ml/min/1.73m2(OR = 2.295, 95%CI = 1.016-5.187), Serum IgA/C3 ratio ≥ 2.59 (OR = 2.505, 95%CI = 1.241-5.057), were independent risk factors for crescent formation. Incorporating these factors, our model achieved well-fitted calibration curves and a good C-index of 0.776 (95%CI [0.711-0.840]) in predicting crescent formation.

CONCLUSIONS

Our nomogram showed good calibration and was effective in predicting crescent formation risk in IgAN patients.