Purpose Systemic lupus erythematosus (SLE) is a chronic, multiorgan, systemic autoimmune disease that is more common in women than men. Men with SLE diagnosed often have a more aggressive clinical course with rapid accrual of organ damage, resulting in a poorer prognosis compared with women with SLE.

Methods This cross-sectional study included 227pts: 69% (n=156) females, aged 35,4±0,8years and 31% (n=71) males, aged 36,1±1,3 years with SLE according to SLICC/ACR 2012 criteria, attending a routine visit at our Clinic between February 2015 and February 2020. Regarding SLE-specific evaluations, patients were assessed for age at onset, disease duration, cumulative organ involvement, cumulative serology and ongoing therapy, SLE Disease Activity Index (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics damage index (SDI).

Results There were no sex differences in: mean age, age at onset (24,5±9,4 years in females and 25,6±11,0 years in males), disease duration (133,7±9,6 and 131,4±12,9 months), SLEDAI-2Kscore (9,51±0,59 and 9,15±0,98), SDI score (1,91±0,16 and 1,85±0,2), steroid use duration (99,8±8,3 and 89,8±10,4 months), taking immunosuppressants in the disease course (49% and 53%). SLE men compared to SLE women had a higher incidence of discoid cutaneous lupus – 23% versus 7%, p<0,001, venous thromboses – 27% vs 15%, p<0,05 and cumulative prednisolone dose -80,1±6,6 vs 39,1±3,4 grams, p<0,001. Oral ulcers (28% vs 46%, p<0,05), Sjögren’s syndrome (1% vs 11%, p<0,05) and taking hydroxychloroquine (30% vs 63%, p<0,00001) appears to be less common in men than in women. No differences were found in the frequency of other clinical and serological disorders (women and men): acute cutaneous lupus – in 63% vs 62%, joint involvement – 90% vs 96%, serositic involvement – 42% vs 54%, nephritis – 53% vs 62%, neuropsychiatric involvement – 30% vs 31%, haematological involvement – 60% vs 46%, ANA - 85% vs 82%, other serological disorders (anti-dsDNA or anti-Sm, or low complement) – 81% vs 69% (p=0,05), antiphospholipid antibodies – 55% vs 41%, antiphospholipid syndrome – 21% vs 30%, arterial thromboses – 11% vs 8%, fever – 25% vs 30%, Raynaud phenomenon – in 25% vs 30% of patients (p>0,05 in all cases).

Conclusions Men with SLE are reported to have more frequent of discoid cutaneous lupus, venous thromboses, high cumulative prednisolone dose and low adherence to hydroxychloroquine therapy. Female sex is associated with a greater frequency of oral ulcers and Sjögren’s syndrome.