University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve”

LABORATORY MEDICINE UPDATE 

October 30, 2001

REFERENCE INTERVAL CHANGE FOR PTT-LA

Effective November 6, 2001, the Special Coagulation Laboratory will change the reference interval for the PTT-LA test, part of the screening panel for the presence of Lupus Anticoagulant.  The new reference interval will be 30.8 to 53.6 s.  This change reflects a broader population study and increased familiarity with this test.

CHANGES IN Hep-PT OFFERING 

The Special Coagulation Laboratory has determined that heparin removal is not necessary in samples with a PTT value of less than 200 s due to a change in the formulation of the PT reagent.  Therefore, if a Hep-PT is requested but the PTT is less than 200 s, treatment with an additional heparin removal agent will not be performed.

ENHANCED PRENATAL SCREENING – QUAD SCREENING

The Davis Laboratory announces the addition of a fourth prenatal marker for assessing risk of Downs in fetal development.  The fourth marker, Dimeric Inhibin A, has been shown to provide increased sensitivity in risk assessment, without increasing the false-positive rate of this screening.  Four-marker screening (Quad screening) yields a detection rate of approximately 76% according to published studies.

Addition of this test to the current Triple Profile does not change sample requirements, handling, or patient preparation.  The charge will be $25.00 more than the current triple screening.  New test request forms are being distributed to facilitate ordering of this fourth marker.  In the interim, clinics may write INHIBIN on the test request form or request QUAD SCREENING.  Triple screening (hCG, AFP, uE3) will continue to be offered.

Questions regarding the clinical or technical details involved in this expanded profile should be addressed to Laura Niewiadomski at (434) 924-2664.  To discuss details regarding billing and account discounts, please contact Rick Ross at (434) 243-2995.

SURGICAL PATHOLOGY REQUISTIONS

Surgical Pathology requisitions are now available online at:

http://hsc.virginia.edu/medcntr/centers/med-labs/requisitions.html

URINE ALBUMIN/CREATININE RATIO

To assist in the diagnosis and monitoring of renal function in patients with diabetes, an Albumin/Creatinine Ratio is recommended by the American Diabetes Association (Diabetes Care, volume 22, supplement 1, January 1999).  

Requested Sample: SPOT URINE

Test Code: UACR

The test MICROALBUMIN should only be ordered for 24-hour urine collections.