Short-Term Effects on Renal Function of EDTA Chelation Therapy in Lead-Associated Nephropathy

Nine patients were studied with past or present exposition to Pb (occupational in 7) and increased Pb body burden, as indicated by a Ca-Na2 EDTA mobilization test (mobilizable Pb 5.750±8.910 μg/72 hours, ranges 1.044 to 27.200). Seven patients had renal insufficiency (GFR < 80 ml/min; ranges 66 to 37), secondary to chronic Pb-associated nephropathy. Chelation therapy with i.m. Ca-Na2 EDTA (from 8 to 24 g) significantly reduced mobizable Pb to 546±211 μg/72 hours (ranges 202–1.400); however no significant changes were seen in GFR, plasma levels and renal handling of urate, blood pressure and antihypertensive therapy need and dosage in hypertensive patients. Only in 3 patients (with actual exposition at the time of diagnosis) GFR slightly increased by 19.8–34.5 %. It is concluded that chelation therapy with Ca-Na2 EDTA has limited short term benefits on renal disfunctions resulting from chronic Pb toxicity.