A SENSITIVE BIOMARKER OF LOW-LEVEL LEAD EXPOSURE
UCLA Technology Available For Licensing

Increasing concerns about biological hazards of minute quantities of lead have recently resulted in downward revision of national toxicity standards from the previous 40 micrograms lead/deciliter of blood to 20µg lead/dl, creating a need for sensitive biomarkers of very low body burdens. Currently available tests are subject to numerous limitations such as unreliability and lack of sensitivity for values below 10-20µg/dl. This limitation is significant because blood lead concentrations in this region have recently been shown to induce irreversible neuropsychologic damage in children. Another limitation of currently available tests is that blood lead concentrations generally reflect recent acute exposure rather than total body burden. Furthermore, traditional tests for lead overburden, such as blood lead, free erythrocyte protoporphyrin, and -amino levulinic acid synthetase, have no internal controls to adjust for patient variables such as anemia, exposure to other substances, age, gender, ethnicity or sex, any of which might skew test results.

This invention proposes tandem assays of two nucleotidase isozymes for detection of human exposure to lead. One isozyme is extremely sensitive to inhibition by lead and other heavy metals whereas the other isozyme is not. The normal ratio of activity for these two isozymes is likely to be a constant in any given individual, but this ratio may be significantly altered in subjects exposed to lead, even down to the very low toxicity region equivalent to 10-20 µg/dl and below. Since both isozymes exhibit elevated activities in young red cells, this test has a built-in internal control to adjust for reticulocytosis associated with anemia. It is also sensitive down to very low levels and indicates total body burden. Accordingly, this test overcomes all of the above referenced limitations of the currently available tests.

The market for human lead testing is expected to be large since the state of California and most every major urban area nationwide mandate lead screening of preschool children.

Reference: UCLA Case No. 1994-507 US Patent Number: 5,871,947

For additional technical details and current licensing
availability, please contact the following UCLA office:

UCLA Office of Intellectual Property
11000 Kinross Avenue, Suite #200
Los Angeles, CA 90095-7231
Tel: 310-794-0558 Fax: 310-794-0638
email: ncd@research.ucla.edu
Lead Inventor: Donald Paglia

UCLA Technologies Available for Licensing
http://www.research.ucla.edu/tech

Copyright © 2000 The Regents of the University of California.

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