Clinical and laboratorial outcome of different age-onset systemic lupus erythematosus patients in Jiangsu, China: a multicentre retrospective study

Studies on clinical features of systemic lupus erythematosus among different age-onset patients are lacking in China. This multicentre study aimed to systemically compare clinical manifestations, comorbidities, organ involvement, and laboratory findings among 797 Chinese juvenile-onset, adult-onset, and late-onset SLE (JSLE, ASLE, and LSLE) patients. They were classified into JSLE, ASLE, and LSLE groups if first diagnosed at < 18, 18–50, and > 50 years old, respectively. Chi-square test and analysis of variance were employed for categorical and continuous variables respectively. In younger-onset patients, the SLE Disease Activity Index 2000 score was significantly higher (JSLE vs. ASLE vs. LSLE = 17.43 ± 9.139 vs. 16.34 ± 8.163 vs. 14.08 ± 6.474, p = 0.031). Mucocutaneous symptoms (79.5% vs. 73.4% vs. 62.0%, p = 0.042), especially malar rash (76.1% vs. 66.1% vs. 53.5%, p = 0.011) occurred more frequently, and proteinuria rate was higher (54.5% vs. 56.3% vs. 36.6%, p = 0.007). In later-onset patients, cardiopulmonary involvement increased (11.4% vs. 24.3% vs. 29.6%, p = 0.012). In ASLE, hypoalbuminemia rate elevated (46.6% vs. 59.9% vs. 47.9%, p = 0.015). Our study demonstrated in a Chinese population that JSLE may be more active and suffer mucocutaneous disorders, while LSLE tended to suffer cardiopulmonary involvement at-onset. These findings may help identify treatment priorities when facing different age-onset SLE patients.