Lead/Creatinine Ratio, Random, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Increased urine lead concentration per gram of creatinine indicates significant lead exposure. Measurement of urine lead concentration per gram of creatinine before AND after chelation therapy has been used as an indicator of significant lead exposure. An increase in lead concentration per gram of creatinine in the post chelation specimen of up to 6X the concentration in the prechelation specimen is normal.
Blood lead is the best clinical correlate of toxicity.
For additional information, see PBBD / Lead with Demographics, Blood.
Detecting clinically significant lead exposure
Urinary excretion of <4 mcg/g creatinine is not associated with any significant lead exposure.
Urinary excretion >4 mcg/g creatinine is usually associated with pallor, anemia, and other evidence of lead toxicity.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not a substitute for blood lead screening.
High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium-or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
<5 mcg/g Creatinine
Reference values apply to all ages.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Kosnett MJ, Wedeen RP, Rotherberg SJ, et al: Recommendations for medical management of adult lead exposure. Environ Health Perspect 2007;115:463-471
2. De Burbane C, Buchet JP, Leroyer A, et al: Renal and neurologic effects of cadmium, lead, mercury, and arsenic in children: evidence of early effects and multiple interactions at environmental exposure levels. Environ Health Perspect 2006;114:584-590
3. Pascal DC, Ting BG, Morrow JC, et al: Trace metals in urine of United States residents: reference range concentrations. Environ Res 1998;76(1):53-59