We investigated whether systemic lupus erythematosus (SLE) patients could be distinguished based on the time of disease onset and, if so, whether the groups differed in their clinical and laboratory features in ethnically homogeneous Korean patients.
We enrolled 201 SLE patients with available clinical data at the time of onset of SLE from the lupus cohort at Chonnam National University Hospital. Sociodemographic, clinical, and laboratory data, including autoantibodies, and concomitant diseases were found at the time of diagnosis of SLE by reviewing patient charts. We divided SLE patients according to age at SLE diagnosis into three groups: juvenile-onset SLE (JSLE, diagnosed at ≤ 18 years), adult-onset SLE (ASLE, diagnosed at 19-50 years), and late-onset SLE (LSLE, diagnosed at >50 years), and compared baseline demographic, clinical, and relevant laboratory findings.
Of the 201 patients, 27 (14.4%), 149 (74.1%), and 25 (12.4%) were JSLE, ASLE, and LSLE patients, respectively. Fever, oral ulcers, nephritis, anemia, and thrombocytopenia were more common in JSLE patients than ASLE or LSLE patients (p < 0.05, < 0.05, 0.001, < 0.05, and < 0.05, respectively). However, Sjögren's syndrome was more frequent in LSLE patients than JSLE or ASLE patients (p < 0.05). Disease activity was significantly higher in JSLE patients than in ASLE or LSLE patients (p < 0.001). Anti-dsDNA and anti-nucleosome antibodies were found more frequently in JSLE patients and less frequently in LSLE patients (p < 0.05 and 0.005, respectively) and decreased complement levels were more common in JSLE patients and less common in LSLE patients (p < 0.001, 0.001, and < 0.05, respectively).
Our results indicate that SLE patients present with different clinical and serological manifestations according to age at disease onset. JSLE patients have more severe disease activity and more frequent renal involvement and LSLE patients have milder disease activity, more commonly accompanied by Sjögren's syndrome, at disease onset.