Risk factors for systemic lupus erythematosus
Gender, ethnicity, and genetic factors are the most important risk factors, and twin studies demonstrate a very high rate of concordance among monozygotic as compared with dizygotic twins. Infectious agents have long been implicated in aetiology, especially the Epstein-Barr virus. However, to date, no firm documentation of a viral cause has been shown.
Systemic lupus erythematosus in the workplace
Until recently, there were few data on work outcomes in patients with SLE. In 2009, Baker and Pope undertook a systematic review of the literature and found 26 studies involving over 9500 patients.72 They estimated a rate of work disability of 20-40 per cent with some 46 per cent of patients in employment. Workplace disability was associated with psychosocial factors and disease factors including age, race, socioeconomic group, educational attainment, activity and, duration of the disease, levels of pain, fatigue, anxiety and neurocognitive function.72 In a longitudinal study of 394 SLE patients, Yelin et al. found that 51 per cent were in employment at baseline of whom 23 per cent experienced work loss over 4 years of follow-up.73 Risk factors for job loss included older age, poorer cognitive and physical function, and depression. Over the same 4 years, 20 per cent of the cohort started new work. This was more likely amongst those with fewer lung manifestations, better physical function, and shorter time since last employment. In younger patients (<55 years), low rates of employment were due to lower rates of starting work rather than higher rates of work loss, but after 55 years both work loss and lower work entry were important.
