Effects of Different Vascular Lesions on the Clinical,Pathological, and Prognostic Features of Lupus Nephritis

Objective To investigate the relationships of various types of renal vascular lesions with the clinical,pathological,and prognostic features of lupus nephritis (LN). Method A retrospective analysis was performed on the clinical and pathological data of LN patients treated in the Peking Union Medical College Hospital over the past 10 years to explore the relationships of different vascular lesions with clinical and pathological features and analyze the effects of renal vascular lesions on kidney prognosis from multiple perspectives. Results Among 644 enrolled LN patients,females accounted for 82.6%,and LN Ⅳ/Ⅳ+Ⅴ (60.4%) was the predominant pathological type.According to the types of renal vascular lesions,the patients were classified into four groups:atherosclerosis (AS)(n=171,26.6%),thrombotic microangiopathy (TMA)(n=78,12.1%),uncomplicated immune complex deposition (ICD)(n=29,4.5%),and lupus vasculopathy (LV)(n=19,3.0%). No renal vascular lesion (NRVL)(n=347,53.9%) was taken as the control group.The average age of patients in the AS group was higher than that in the other groups (all P<0.001).The TMA (P=0.009,P=0.025) and LV groups (P=0.007,P=0.005) had lower levels of complement C3,and higher disease activity index of systemic lupus erythematosus and incidence of acute kidney injury (both P<0.001) than the NRVL and AS groups.The TMA (P<0.001),LV (P<0.001),and AS (P=0.037) groups had lower estimated glomerular filtration rate (eGFR) than the NRVL group,and the eGFR of the TMA group was lower than that of the LV,AS,and ICD groups (all P<0.001).The renal pathological activity index (AI) of each renal vascular lesion group was higher than that of the NRVL group (all P<0.001),and the AI value of the TMA and LV groups was higher than that of the AS group (both P<0.001).There was no significant difference in AI value between TMA and LV groups (P=0.675),while the proportion of fibrinoid necrosis in the LV group was higher than that in the TMA group (P=0.012).The TMA group had the highest degree of chronicity and higher chronic index than the AS (P=0.021),LV (P<0.001),ICD (P<0.001),and NRVL (P<0.001) groups.The AS group had the secondary highest degree of chronicity and higher median chronic index than the NRVL group (P=0.004).The TMA group had the lowest 1-year clinical remission rate and the highest proportion of annual eGFR decline >5 mL/(min·1.73 m²).Both TMA and AS groups showed lower long-term renal survival rates than the NRVL group (P<0.001,P=0.023) respectively. Conclusions Intrarenal vascular lesions are strongly associated with clinical severity and prognosis in LN.LV correlates with acute kidney injury and severe active renal injury,while TMA is the most severe subtype and characterized by high pathological activity,chronicity,poor treatment response,and adverse outcomes.AS,the most common type,does not affect treatment response but predicts unfavorable long-term renal survival.