Objective To evaluate the correlation between the prognostic nutritional index (PNI) and crescentic lesions in patients with IgA nephropathy (IgAN).

Methods A retrospective analysis was conducted on 138 patients diagnosed with IgAN via renal biopsy. Crescentic lesions were assessed using the Oxford classification. The predictive value of PNI for crescentic lesions in IgAN patients was analyzed using ROC curves, and the optimal cutoff value was determined. Participants were divided into two groups based on the cutoff value of 46.6. Clinical data, laboratory results, and pathological indicators were compared between the two groups. The relationship between PNI and crescentic lesions, correlation analysis and binary logistic regression analysis were performed.

Results Compared with the high-PNI group, the low-PNI group exhibited lower proportions of males, eGFR, hemoglobin, serum albumin, serum IgG, and lymphocyte count, as well as lower rates of RASB use (P ＜ 0.01). The proportions of E1 and C1/2 were higher in the low-PNI group than in the high-PNI group (P ＜ 0.01 to P ＜ 0.05). Compared with the C0 group, the C≥1 group showed reduced eGFR, PNI, serum albumin, and serum IgG, as well as lower RASB usage rates, while 24-hour urinary protein, serum creatinine, serum cholesterol, and serum C4 levels were elevated (P ＜ 0.01 to P ＜ 0.05). PNI was negatively correlated with 24-hour urinary protein, serum creatinine, blood urea nitrogen, and crescentic lesions (P ＜ 0.01), but positively correlated with eGFR, hemoglobin, serum albumin, serum IgG, and lymphocyte count (P ＜ 0.05 to P ＜ 0.01).

Conclusions Serum IgG and PNI are independent protective factors for crescentic lesions in IgAN and can serve as predictive indicators for crescentic lesions in IgAN.