Materials and methods. The study included 800 patients with a confirmed diagnosis of SLE according to the 2012 SLICC (Systemic Lupus International Collaborating Clinics) classification criteria. All patients underwent standard clinical, laboratory and instrumental examinations. To analyze gender differences, patients were divided into two groups: group 1 consisted of 65 (8.1%) men (mean age 33.5±10.5 years), group 2 – 735 (91.9%) women (mean age 35.5±12.3 years). All patients underwent standard clinical, laboratory and instrumental examination.

Results and discussion. At the time of inclusion in the study, male and female patients did not differ in age, ethnicity, education, comorbidities, course, or activity of SLE (p>0.05), except for disease duration, which was significantly shorter in men than in women (p<0.05). Among the clinical manifestations of SLE, men were significantly more likely than women to have severe forms of lupus nephritis with a predominance of nephrotic syndrome and acute kidney injury, combined involvement of the central (CNS) and peripheral nervous systems (PNS), a high frequency of arthritis, mesenteritis and exudative pleuritis (p<0.05). In women, with a high prevalence of mucocutaneous manifestations (93.6%) and alopecia (71.6%), renal and nervous system (NS) involvement was observed in approximately 40% of cases (35.9% and 40.1%, respectively). The irreversible organ damage (IOD) was detected in 163 patients, including 22 (13.5%) men and 141 (86.5%) women. A significant proportion of patients with IOD had NS involvement – 50 (6.3%), including 7.7% of men and 6.1% of women. The next most common type of injury was kidney involvement, which was observed in 40 (5%) patients, significantly more often in men than in women (7 (10.8%) vs. 33 (4.5%); p=0.04). In addition, men were statistically significantly more likely to have peripheral vascular damage and skin changes (1 (1.5%) vs. 1 (0.1%), respectively; p=0.03) and (2 (3.1%) vs. 3 (0.4%), respectively; p=0.01). Adverse prognostic factors for severe SLE in male patients were C4 hypocomplementemia (p=0.012), previous accumulation of IOD (p=0.006), arthritis (p=0.009), active LN with high serum creatinine (SC) values (p=0.02), and protein loss of more than 500 mg/day (p=0.001). At the same time, independent predictors of severe SLE in women included acute disease course (p=0.024), C3 hypocomplementemia (p=0.031), positive anti-Smith antibodies (p=0.043), PNS involvement (p=0.024), and active SLE with proteinuria more than 500 mg/day (p=0.015).

Conclusions. Patients in the Kyrgyz cohort show a similar gender pattern in the clinical course, activity, laboratory, and immunological manifestations of SLE. However, compared to women, men have a higher incidence of mesenteritis, exudative pleuritis, oligoarticular arthritis, severe forms of vasculitis, combined CNS and PNS involvement, as well as early accumulation of damage mainly to the kidneys, skin PNS. At the same time, women more frequently present with mucocutaneous manifestations, alopecia and fever, while renal and NS involvement occurs in approximately 40% of cases. Independent predictors of the risk of severe SLE in men are C4 hypocomplementemia, earlier accumulation of IOD, joint involvement, active LN with high SC values and protein loss of more than 500 mg/day. In women, predictors include acute disease onset, C3 hypocomplementemia, positive anti-Smith antibodies, PNS involvement and proteinuria >500 mg/day.