[Risk factors and prognosis of pediatric silent lupus nephritis with class Ⅲ to Ⅴ]

To study the risk factors and prognostic characteristics of pediatric silent lupus nephritis (SLN) with class Ⅲ to V.

A retrospective study was conducted to collect clinical data from 30 children diagnosed with SLN at the Department of Pediatrics, Second Xiangya Hospital, Central South University, from May 2007 to April 2023. Based on renal pathological classification, the patients were divided into a class Ⅱ group (12 cases) and a class Ⅲ to Ⅴ group (18 cases). The risk factors for the occurrence of class Ⅲ to Ⅴ SLN were analyzed, and the prognostic characteristics were summarized.

Among the 30 SLN patients, the median follow-up time was 61.50 months. There were no statistically significant differences in the proportions of patients who discontinued glucocorticoids or achieved low disease activity status, nor in the annual decline rate of estimated glomerular filtration rate (eGFR) between the class Ⅱ and class Ⅲ to V groups (P>0.05). However, three patients in the class Ⅱ group progressed to stage 1 chronic kidney disease (CKD), while eight patients in the class III to V group reached stage 1 CKD, and four patients reached stage 2 CKD. Among the 26 female SLN patients, serum complement C3 levels in the class III to V group were lower than those in the class Ⅱ group (P<0.05). Serum C3 levels in SLN patients, as well as in female SLN patients, were negatively correlated with the fluorescence intensity of IgA, IgG, and C3 immune complexes in the kidneys (P<0.05). Additionally, serum C3 levels in female SLN patients were negatively correlated with the renal pathological activity index (P<0.05). Binary logistic regression analysis indicated that being female and having low serum complement C3 levels were risk factors for the occurrence of class Ⅲ to V SLN in children (P<0.05).

Class Ⅲ to V SLN is not uncommon among SLN children, and there remains a risk of long-term renal function progression. Being female and having low serum complement C3 levels are identified as risk factors for class Ⅲ to V SLN in children.