Chronic lead nephropathy in Queensland: alternative methods of diagnosis.

Indices of past lead absorption were measured and compared in patients with chronic renal failure from many causes, including some with chronic lead nephropathy. X-ray fluorescence (XRF) yielded finger bone lead concentrations by a new in vivo method. These correlated significantly with excess urinary lead following calcium di-sodium EDTA (ethylenediamine tetra-acetate) and erythrocyte lead concentration. Discriminant function analysis demonstrated that the patients in the study could be separated into two groups without any reference to the EDTA lead excretion test using the following variables, all of which contributed significantly to the discrimination. In order of importance, these were: a childhood history of acute lead poisoning, a history of gout, a family history of gout and detectable XRF finger bone lead. Although the XRF finger bone lead measurement is convenient and non-invasive, its lack of sensitivity (48%) limits its usefulness as a screening test for chronic lead nephropathy.