Disappearance of Immune Deposits with EDTA Chelation Therapy in a Case of IgA Nephropathy

Abstract

In this report, we describe the development of renal function impairment in a 33-year-old patient with mesangial IgA nephropathy and a history of recent gout. Increased body lead burden was identified with a positive EDTA mobilization test. The patient was treated with 1 g of edetate disodium calcium weekly for 2 months until normalization of urinary lead excretion. Improvement of renal function and proteinuria were noted. It was even more interesting to find that both immunofluorescence and electron microscopy studies of the second biopsy specimen revealed the loss of previous mesangial immune deposits. Our case demonstrated that lead may be a nonspecifically damaging factor related to the deterioration of renal function in patients with preexisting renal disease. Moreover, the disappearance of mesangial immune deposits after chelation therapy has not been previously documented. The pathogenetic basis of this observation is unknown, and its causal relationship with lead requires further elucidation.

Environmental Lead Exposure and Progressive Renal Insufficiency

“…The EDTA chelating agent is safe in treating patients with CRI with a smaller dose and a longer interval. 3,9,12,24 Wedeen et al 25 extensively used EDTA as test doses in large numbers of patients and as therapy in a smaller number, yet they never encountered any evidence of nephrotoxicity. The same findings were also noted in previous studies.…”

“…The same findings were also noted in previous studies. [2][3][4][9][10][11][12][13]16 Hence, the EDTA chelation therapy might be a better alternative to treat patients with progressive renal insuffi- Kaplan-Meier estimates of primary renal outcome in patients with chronic renal insufficiency who had high-normal (Ն80 µg and Ͻ600 µg) and low (Ͻ80 µg) body lead burdens (BLBs) (PϽ.001 by log-rank test). ciency.…”

“…The most reliable measurements of BLB are attained using bone radiograph fluorescence and EDTA mobilization tests. 8 In previous works, [9][10][11][12][13] investigators used the EDTA mobilization test to assess the BLB of patients with ORIGINAL INVESTIGATION chronic renal disease without previous lead exposure. They demonstrated that long-term low-level environmental lead exposure (1) may be associated with impaired renal function 9,10 in a small group of patients, (2) can subtly affect urate excretion in patients with chronic renal disease, 11 and (3) is associated with renal tubular and glomerular damage in a general population.…”

“…They demonstrated that long-term low-level environmental lead exposure (1) may be associated with impaired renal function 9,10 in a small group of patients, (2) can subtly affect urate excretion in patients with chronic renal disease, 11 and (3) is associated with renal tubular and glomerular damage in a general population. 12,13 However, whether long-term low-level environmental lead exposure is associated with the progression of renal insufficiency remains unknown. In addition, although lead chelation therapy has been successfully introduced to treat chronic lead-related nephropathy 2,3 in persons with occupational exposure to lead and rats with long-term low-level lead exposure, 14 the efficacy of this therapy for patients with low-level environmental lead exposure is unknown.…”

Do people from Taiwan have higher heavy metal levels than those from Western countries?

“…(19)(20)(21) Lin et al conducted EDTA mobilisation tests to assess the body burden of lead in patients with different degrees of renal insufficiency and no known lead exposure; their results suggest that long-term, low-level environmental lead exposure may be associated with the progression of renal insufficiency. (8,9) They also showed that long-term, low-level environmental lead exposure may be associated with renal tubular and glomerular damage in patients with immunoglobulin A nephropathy (22) and in residents who had been living near a lead battery factory for more than ten years. (23) The findings of these studies suggest that there may be a positive association between long-term lead exposure (resulting in a high body burden of lead) and impaired kidney function.…”