Laboratory Medicine Updates - 9/4/2001

University of Virginia Health System
Medical Laboratories
"Quality You Expect, Service You Deserve"

LABORATORY MEDICINE UPDATE
September 4, 2001

HPV Testing

The Molecular Diagnostics division of the Medical Laboratories, in conjunction with the Cytopathology laboratory, will offer "High Risk Human Papillomavirus (HPV) Testing" on ThinPrepTM specimens submitted for equivocal gynecological cytopathology results (e.g. ASCUS or AGUS Pap smears collected via ThinPrepTM) beginning September 2, 2001. This test is designed to identify women infected with one of thirteen intermediate/high risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68) that may be associated with cervical cancer or its precursors. This test is a semi-quantitative test that identifies any HPV in this group but does not identify the specific HPV type(s) present. HPV testing via this Hybrid Capture IITM assay has been found to be more sensitive than repeat cytology in detecting prevalent HSIL or cancer in women initially diagnosed with ASCUS* and, based on more recent data, AGUS as well. Therefore, physicians ordering ThinPrepTM analyses will have the option of selecting a reflex HPV test to be performed on the original specimen submitted for a patient primarily diagnosed with ASCUS or AGUS.

The results of any such reflex testing will be appended to the original Cytopathology report for assistance in patient management and follow-up testing.

*D Solomon, M Schiffman, and R Tarone. Comparison of Three Management Strategies for Patients with Atypical Squamous Cells of Undetermined Significance: Baseline Results from a Randomized Trial. J Natl Cancer Inst 94(4):293-299, 2001.

Genetic Testing for Mutations Associated with Hemochromatosis*
The Molecular Diagnostics division of Medical Laboratories now offers genetic analysis for mutations associated with risk of development of hemochromatosis. Analysis is conducted by Real-Time PCR on the Roche LightCycler. The two most common mutations associated with increased risk (C282Y and H63D) will be assessed. The technology allows for the determination of a third mutation (S65C). While S65C is considered a benign polymorphism, a C282Y/S65C genotype may confer a slight increased risk for mild disease phenotype. All results will be followed by an analysis prepared by a Director of the Laboratory to assist in the interpretation of the results. The most common associations with disease based on population statistics are:
C282Y: Homozygous mutations are associated most strongly with patients of European decent. Published studies show the frequency of C282Y homozygosity in hemochromatosis patients to be 64% in the Italian population, 80-90% in the English and French population and 100% in the Australian population. The mutation is either absent or has low allele frequency in non-Caucasian populations. The association of homozygous genotype with phenotypic expression as measured by increased transferrin saturation and biochemical or histologic hepatic iron index values is age related and gender influenced. Penetrance in men >40 years of age is 95% and in men <40 years of age it is 80%. Penetrance in women >40 years of age is 80% and in women <40 years of age is 39%. H63D: This mutation appears to have little effect when inherited alone, but may contribute to manifestations of hemochromatosis when inherited with the C282Y mutation, producing a compound heterozygous genotype. The two independent mutations are most frequently inherited on separate chromosomes. Many compound heterozygotes in the general population are asymptomatic.

*E Lyon and E L Frank. Hereditary Hemochromatosis Since Discovery of the HFE Gene. Clinical Chemistry 47:1147-1156, 2001.

Laboratory Clinical Trials Coordinator
UVA Medical Laboratories is pleased to announce the creation of our newest program, designed to assist researchers and industry partners in transforming new ideas into marketable products. The Medical Laboratories Clinical Trials Program is led by a certified Medical Technologist who will work with internal and external partners to expand collaborative and translational opportunities. With the assistance of our Faculty and professional staff, we can offer comprehensive assistance to a wide range of clinical trial work. Our initial focus will be on instrument evaluations, validation of methodologies, and alpha/beta site testing, although we will attempt to support any clinical trial that needs our services. Clinicians and industry representatives interested in learning more about our new Program should contact Christine Harper, Clinical Trial Coordinator, at 434-924-5691 or via e-mail at CBH8T@virginia.edu.

Serum hCG Testing Discontinued in Primary Care Lab

Beginning on September 1, 2001, the Primary Care Laboratory (PCC2) will no longer perform serum Qualitative hCG testing on-site. All requests for serum testing will be sent to the Core Laboratory. Urine Qualitative hCG testing will continue to be offered at the Primary Care Laboratory. Page 1 of 1