Systemic lupus erythematosus among male patients in Malaysia: how are we different from other geographical regions?

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease which predominantly affects females. The disease characteristics in male SLE patients are reported to be distinct and may vary across ethnicities and geographical regions.

OBJECTIVE: To determine and compare the clinical phenotype and organ damage between male and female patients with SLE in Malaysia.

METHODOLOGY: This was a cross-sectional study involving SLE patients from Universiti Kebangsaan Malaysia Medical Centre from June 2016 until June 2017. Information on their socio-demographics and disease characteristics were obtained from the clinical records. Disease damage was assessed using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI) scores. The disease characteristics, autoantibody profiles and organ damage were compared between male and female patients, and multivariable analysis using male sex as dependent variable was then performed.

RESULTS: A total of 418 patients were recruited and a total of 59 (14.1%) patients were male. Male patients presented with lower SLE ACR criteria at initial presentation but a significantly higher number of them had renal involvement (lupus nephritis) (78.0% versus 63.8%, p = 0.04). Male patients had less musculoskeletal involvement (45.8% versus 63.0%, p = 0.02) and tended to have lesser mucocutaneous involvement. Immunologic profile revealed that a lower number of male patients had positive anti-Ro antibody (22.7% versus 44.7%, p = 0.04) and they tended to have positive lupus anticoagulant antibody (27.6% versus 14.3%, p = 0.06). Presence of organ damage (SDI score ≥ 1) was significantly higher among males (55.9% versus 39.6%, p = 0.02) with higher renal damage (25.4% versus 9.2%, p = 0.004) and cardiovascular event of ischaemic heart disease or stroke (20.3% versus 7.0%, p = 0.004). They were also inclined to develop damage much earlier as compared to female patients, 3 (interquartile range (IQR) 7.5) versus 5 (IQR 7) years, p = 0.08. The occurrence of disease damage was independently associated with male gender with odds ratio of 1.9 (95% confidence interval 1.1-3.5), p = 0.02.

CONCLUSION: Male patients with SLE have more severe disease with renal damage and cardiovascular event.