Kidney biopsy in systemic lupus erythematosus

Objective. To examine the importance of renal biopsy as a predictor of death due to any cause in patients with systemic lupus erythematosus (SLE). Methods. The study included 123 SLE patients who had a renal biopsy between 1970 and 1984 and were followed up as part of a prospective study. Data were initially analyzed to identify clinical and laboratory features that were significantly associated with the risk of dying. Renal biopsy variables were then examined to determine whether they contributed additional information about prognosis. Results. The clinical and laboratory factors most closely associated with the risk of dying in multivariate analyses were the serum creatinine level and the SLE Disease Activity Index score. The presence of chronic renal lesions on biopsy contributed significantly to the prognostic information offered by clinical and laboratory factors in the subset of patients who had normal serum creatinine levels—the majority (85%) of patients in this study. Conclusion. These results indicate that renal biopsy serves an important role in the assessment of prognosis in patients who do not have advanced renal disease.     

Malignancy in systemic lupus erythematosus

Objective. To estimate the risk of cancer in patients with systemic lupus erythematosus (SLE). Methods. Patients with SLE (n = 724) have been followed prospectively, for 24 years, at the University of Toronto Lupus Clinic. The diagnosis of cancer was confirmed by histologic or autopsy reports. Standardized rates of cancer and standardized incidence rates (SIR) (ratio of observed-to-expected cancers) were used to estimate the risk for cancers. Results. Twenty-four cancers were identified in 23 SLE patients (3.2%) during 7,233 patient-years of followup. Compared with the Ontario population, the overall estimated risk for all cancers was not increased in the lupus cohort (SIR 1.08, 95% confidence interval 0.70–1.62). A 4.1-fold increased risk for hematologic cancers was observed, due mainly to an increased risk of non-Hodgkin's lymphoma. The risk for cancer was significantly lower in the SLE cohort compared with patients with rheumatoid arthritis (RA) and systemic sclerosis (SSc). Conclusion. SLE is associated with a lower risk of all cancers compared with RA and SSc, but an increased risk for non-Hodgkin's lymphoma compared with the general population.     

The significance of thrombocytopenia in systemic lupus erythematosus

The significance of thrombocytopenia in systemic lupus erythematosus (SLE) is unclear. Some researchers have found it associated with severe disease, others with mild disease. Thrombocytopenia (platelets < 100,000) occurred in 21 patients seen at an SLE clinic over 18 months. Prospective assessment of 19 (non-SLE causes excluded) revealed 2 distinct subgroups. Seven were thrombocytopenic only during severe multisystem flares. Twelve had chronic thrombocytopenia with intermittent mild flares in other systems. Serious bleeding was rare in both subgroups. It was concluded that thrombocytopenia clearly is not a prognostic indicator.