['Systemic lupus erythematosus (SLE) mostly occurred in young women. This study was undertaken to investigate the different clinical characteristics of SLE between male and female patients, and to identify the sex hormone levels and clinical outcomes of different gender in SLE patients.', "Of the 516 SLE patients admitted to the Peking University People's Hospital from January 2008 to December 2010, 58 were male and 458 were female. Clinical manifestations, laboratory profiles and disease activity scores were evaluated in male and female patients. Sex hormones levels were also compared among male patients.", 'The median age at SLE onset in male and female patients was 27.2 and 28.6 years, respectively. Compared with female patients, at onset of SLE, male patients showed higher rates of serious renal disease (58.6% vs. 47.2%, P = 0.064), neuropsychiatric SLE (20.7% vs. 12.0%, P = 0.055), and a higher incidence of anti-ds-DNA (25.9% vs. 16.8%, P = 0.069), anti-Sm (17.2% vs. 8.7%, P = 0.002), anti-Ro (46.6% vs. 28.4%, P = 0.004), anti-U1RNP (29.3% vs. 15.3%, P = 0.010), anticardiolipin antibody (25.9% vs. 11.4%, P = 0.004), and decreased C3 levels (67.2% vs. 49.8%, P = 0.009). Systemic lupus erythematosus disease activity index (SLEDAI) scores were higher in men than in women (16.8 vs. 12.8, P = 0.038). Of the 58 male patients, 24 had not received aggressive treatment during the three months prior to the study. Levels of testosterone and dihydroepiandrosterone (DHEA) were lower in male SLE patients than in male healthy controls (P = 0.004 and P = 0.006, respectively). Low serum testosterone was an independent risk factor for the development of lupus nephritis (P = 0.043). Male patients with elevated serum prolactin were at increased risk of developing neuropsychiatric manifestations of SLE (P = 0.081).'] Are gender differences associated with the clinical features of systemic lupus erythematosus?