The presence of renal involvement in patients with lupus was associated with a significantly increased mortality risk, a longitudinal Chinese study found.
Compared with lupus patients without nephritis, the hazard ratios for death among patients with renal disease and renal damage were 2.23 (95% CI 1.29-3.85, P=0.004) and 3.59 (95% CI 2.20-5.87, P<0.001), respectively, according to , of Tuen Mun Hospital in Hong Kong, and colleagues.
Action Points
- The presence of renal involvement in patients with lupus, in particular proliferative nephritis, was associated with a significantly increased mortality risk.
- Point out that patients with proliferative forms of nephritis had increased mortality risk, whereas those with membranous nephropathy did not.
And for those who had progressed to end-stage renal disease, the risk was nine times higher than for those without kidney involvement (HR 9.20, 95% CI 4.92-17.2, P<0.001), the researchers reported in the August Arthritis & Rheumatism.
Some previous research has examined the relative mortality risk with lupus nephritis and found that the likelihood of death remains elevated even with recent improvements in treatment.
However, only and life expectancy.
Accordingly, Mok and colleagues enrolled 694 newly diagnosed patients with systemic lupus erythematosus (SLE) for their study, seeing them at regular 3-month intervals.
Mean age at disease onset was 33, and mean follow-up was almost 10 years. More than 90% were women.
Renal disease was present in 53%, and almost half of affected patients had class IV nephritis.
Renal damage, assessed on the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, was identified in 11%, and end-stage renal disease was present in 3%.
Patients with proliferative forms of nephritis had increased mortality risk (HR 2.28, 95% CI 1.22-4.24, P=0.01), whereas those with membranous nephropathy did not (HR 1.09, 95% CI 0.38-3.14, P=0.88).
"Among the different histologic types of lupus nephritis, it is well known that diffuse and focal proliferative nephritis carries a worse prognosis than the pure membranous type of nephritis, in terms of progression to [end-stage renal disease]," the researchers noted.
However, in one report, there was an among patients with membranous nephritis.
Compared with the general population, the standardized mortality ratios were:
- All lupus patients: 7.3 (95% CI 5.7-9.3)
- No renal disease: 4.8 (95% CI 2.8-7.5)
- Renal disease: 9 (95% CI 6.7-11.9)
- Proliferative nephritis: 9.8 (95% CI 6.5-14.1)
- Pure membranous nephritis: 6.1 (95% CI 2-14.1)
- Renal damage: 14 (95% CI 9.1-20.5)
- End-stage renal failure: 63.1 (95% CI 33.6-108)
Life expectancy was shortened by 12.4 years for those with SLE, by 15.1 years for those with renal disease, and by 23.7 years for those with renal damage compared with the general population.
"Thus, the occurrence of renal damage is an important adverse factor for survival in patients with SLE," Mok and colleagues observed.
The standardized mortality ratios seen in this study of Chinese patients were similar to those found in other populations, according to the researchers.
For instance, in one North American study, was 7.9 (95% CI 5.5-11).
"In this study on the cumulative survival, [standardized mortality ratio], and life expectancy of a large longitudinal cohort of southern Chinese patients with SLE, we showed that the presence of glomerulonephritis, in particular the proliferative types causing renal insufficiency, significantly reduces the survival and life expectancy of patients with SLE," the researchers concluded.
"Better management of lupus renal disease may help to improve the ultimate prognosis of the disease," they added.
Disclosures
The lead author has received financial support from Pfizer and GlaxoSmithKline.
Primary Source
Arthritis & Rheumatism
Source Reference: Mok C, et al "Effect of renal disease on the standardized mortality ratio and life expectancy of patients with systemic lupus erythematosus" Arthritis Rheum 2013; 65: 2154-2160.