Laboratory Medicine Updates - May 22, 2003

University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve”

LABORATORY MEDICINE UPDATE

May 22, 2003 

Qualitative Enterovirus Analysis by Real Time PCR Now Available

The Molecular Diagnostics Laboratory is now offering a real-time PCR assay for Enterovirus RNA detection.  The procedure¹ has been validated to detect RNA extracted from the following serotypes and is expected to work for other enteroviruses based on similarities in RNA sequences.

Coxsackievirus A9 and B5

Echovirus 1, 6, and 11

Enterovirus 71

Poliovirus 1

Test Name: Enterovirus by PCR (EVPCR)

MIS screen: CSF guide under “E”

CPT Codes: 83891, 83902, 83898, 83896x2, 83912

Cost: $246.70

Sample Requirements: CSF only

Minimum Volume: 0.5 mL

Add-on Limitations: Specimens must be refrigerated after collection for storage less than 24 hours and frozen at -20^oC for longer storage.  Centrifuged specimens are not acceptable.

Availability and Turnaround Time: Monday through Friday, 1 working day

Reference Interval:  None Detected

Please contact the Chemistry resident on-call (pic 1267) with any questions.

¹Watkins-Riedel, T., Woegerbauer, M., Hollemann, D., Hufnagl, P.  Rapid diagnosis of Enterovirus infections by real-time PCR on the LightCycler using the TaqMan format. Diagnostic Microbiology and Infectious Disease, 42, 99-105, 2002

Change in Reporting Units for High-Sensitivity C-Reactive Protein (hsCRP)

The hsCRP test is used to assess risk of cardiovascular disease.  To meet recently published guidelines¹  from the CDC and the American Heart Association (AHA), results for hsCRP will be reported in mg/L rather than mg/dL, increasing all results by a factor of 10.  The following risk categories¹ will be appended to each result according to the CDC/AHA guidelines:

         <1.0 mg/L low
        1.0 - 3.0 mg/L average
        >3.0 mg/L high

The recommendations include collecting two specimens two weeks apart and using the mean of the two results to assess risk.  Any value over 10 mg/L should be investigated for potential underlying inflammatory disorder and not used for assessment of risk of cardiovascular disease.

Specimen type: Serum (gold-top).

Minimum volume: 1 mL whole blood (0.5 mL serum)

The traditional CRP test is still available. The test cannot measure CRP at the low concentrations measured by the hsCRP test for cardiovascular risk stratification.  Note that results of the traditional CRP test are reported in mg/dL and thus are lower by a factor of 10 (because of the units) than hsCRP results.

  ¹Pearson, Mensah et al. Markers of Inflammation and Cardiovascular Disease: Application to Clinical and Public Health Practice.  A Statement for Healthcare Professionals from the Centers for Disease Control and Prevention and the American Heart Association.  Circulation 107:499-511, 2003.