To the editor: We read with some concern the article by Kimberly and colleagues (1) stating that true glomerular filtration rate was depressed in patients with systemic lupus erythematosus taking aspirin. The article may be misleading in several respects.
The most striking inconsistency appears when one analyzes the measurements of glomerular filtration rate. Although the mean value for inulin and creatinine clearance is only slightly different in the control period, impressive differences are evident when these measurements are compared in three of the six patients. Firm evidence exists supporting the good correlation between endogenous creatinine clearance and inulin clearance over