For patients with systemic lupus erythematosus (SLE), compromised kidneys significantly reduce survival and life expectancy, according to a study published online Arthritis & Rheumatism.
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% women; age of onset, 32.9).
The researchers found that 53% of patients had renal disease. After a mean of 9.6 years, renal damage was present in 11% of patients, and end-stage renal disease (ESRD) developed in 3%. Compared to patients without, those patients with renal disease, renal damage, and ESRD had a significant 2.2, 3.6, and 9.2 times increased risk of age- and sex-adjusted mortality, respectively. The researchers found a significant increase in mortality associated with proliferative types, but not pure membraneous, lupus nephritis. Non-renal SLE patients, patients with lupus nephritis, proliferative nephritis, pure membranous nephritis, renal damage, and ESRD had age- and sex-adjusted standardized mortality ratios 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 investigators concluded.