Objective: Although there have been many studies on systemic lupus erythematosus (SLE) patients, there are few data about survival analysis of lupus patients receiving dialysis. Therefore, the objective of this study is to analyze risk factors predicting mortality in lupus patients treated with peritoneal dialysis (PD). In addition, we also delineate the relationship between predialysis comorbid illnesses, damage accrual, and mortality in lupus patients undergoing PD.
Methods: This longitudinal cohort study included 38 lupus patients undergoing PD between 1990 and 2008. The clinical parameters, disease activity (non-renal SLEDAI, nrSLEDAI), comorbid illnesses, and damage accrual were collected. We applied the Charlson Comorbidity Index (CCI), Khan Index, and Davies Index to elucidate the impact of predialysis comorbidity on mortality. Moreover, we examined prognostic value of predialysis SDI (Systemic Lupus International Collaborating Clinics Disease Damage Index) for lupus PD patients.
Results: There were 33 women and five men included for analysis. The mean age at PD entry was 32.2 +/- 10.4 years and mean duration of PD was 39.7 +/- 22.4 months. The nrSLEDAI score during PD significantly decreased, compared to the predialysis one (2.13 +/- 2.09 vs. 4.00 +/- 3.08, p < 0.001). All comorbidity indices and SDI scores were significantly and positively correlated with each other (p < 0.001). Univariate Cox regression analysis showed that serum creatinine level, date at PD entry, and the CCI were predictors for mortality. The predialysis nrSLEDAI and SDI scores did not have roles in predicting mortality of lupus PD patients.
Conclusions: The predialysis CCI, instead of SDI, determines an increased risk for mortality in lupus patients treated with PD. The prognosis of lupus patients treated with PD largely depends on the severity of predialysis comorbidity, especially cardiovascular diseases.