To examine the effect of renal disease on standardized mortality ratios (SMRs) and life expectancy of patients with SLE, Chi Chiu Mok, MD, from Tuen Mun Hospital in Hong Kong, and colleagues analyzed longitudinal data (1995 to 2011) from 694 patients with four or more American College of Rheumatology criteria for SLE (92 percent women; age of onset, 32.9 ± 13.4 years).
The researchers found that 53 percent of patients had renal disease. After a mean of 9.6 years, renal damage was present in 11 percent of patients, and 3 percent developed end-stage renal disease (ESRD). Compared to patients without, those patients with renal disease, renal damage, and ESRD had significantly increased age- and sex-adjusted hazard ratios for mortality (2.23, 3.59, and 9.20, respectively). There was a significant increase in mortality associated with proliferative types, but not pure membraneous, lupus nephritis (adjusted hazard ratio, 2.28 [P = 0.01] and 1.09 [P = 0.88], respectively). Non-renal SLE patients, patients with lupus nephritis, proliferative nephritis, pure membranous nephritis, renal damage, and ESRD had age- and sex-adjusted SMRs of 4.8, 9.0, 9.8, 6.1, 14.0, and 63.1, respectively. For SLE patients with renal disease and renal damage, life expectancy was reduced by 15.1 and 23.7 years, respectively, compared with the population.
"The presence of renal disease, in particular proliferative nephritis causing renal insufficiency, significantly reduces survival and life expectancy of SLE patients," the authors write.