Platelet (PLT), eosinophil (EOS), and albumin (ALB) are useful indicators for evaluating the risk of developing lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE) Running head: indicators for evaluating the risk of developing lupus nephritis

Abstract

Objectives Although there have been extensive investigations of platelet (PLT), eosinophil (EOS), and albumin (ALB) in many diseases, their roles in systemic lupus erythematosus (SLE) with lupus nephritis (LN) remain unclear. Thus, the present study aimed to evaluate the value of PLT, EOS, and ALB levels and provide guidance for the clinical application of PLT, EOS, and ALB detection in Chinese SLE patients with LN. Methods Among 2060 enrolled SLE patients undergoing hospitalization, we included a total of 73 patients diagnosed with LN and 325 SLE patients without LN who completed the measurement of blood and LN screening between 2018 and 2022. All clinical characteristics and the blood measurement information of SLE patients were extracted and analyzed from the medical records. Univariate and multivariate logistic regression analyses were used to evaluate the possible relationship of PLT, EOS, and ALB to LN. Receiver operating characteristic (ROC) curve analysis was also performed to assess the discriminative ability of three ratios in predicting LN. The nomogram was performed to facilitate an individualized estimation of the risk of lupus nephritis in SLE patients. Results The LN group had lower PLT, EOS, and ALB levels than the SLE group (P < 0.01). Univariate logistic regression analysis indicated that three risk factors for LN were identified, including PLT (OR = 0.393, 95% CI 0.172–0.896, P = 0.026), EOS (OR = 0.108, 95% CI 0.027–0.439, P = 0.002), and ALB (OR = 0.351, 95% CI 0.127–0.972, P = 0.044). Multivariate logistic regression analysis also showed that, compared with the low groups, the high PLT group, high EOS group, and high ALB group had a lower risk of LN. In addition, ROC analysis and the nomogram comprised of PLT, EOS, and ALB revealed that these three predictors were determined as predictive indicators of LN in SLE patients and exhibited sufficient predictive accuracy, with the area under the characteristic curve (AUC) of 0.720 [95% confidence interval (CI) 0.658–0.782]. Conclusions Decreased levels of PLT, EOS, and ALB might be correlated with an increased risk of LN in Chinese SLE patients.