Laboratory Medicine Updates - July 14, 2006

University of Virginia Health System

Medical Laboratories

"Quality You Expect, Service You Deserve"

LABORATORY MEDICINE UPDATE

July 14, 2006

Breakage testing using Diepoxybutane (DEB) for Fanconi Anemia

Beginning July 1, 2006, the Cytogenetics Laboratory will no longer perform breakage testing using diepoxybutane (DEB) for the diagnosis of Fanconi Anemia.  This test will be a send out to the Cytogenetics Laboratory of Dr. Arleen Auerback at Rockefeller University.  The DEB sensitive breakage testing can be performed on peripheral blood, amniocytes, CVS and fibroblasts.  Peripheral blood samples should be sent to Specimen Receiving Attn: Referral Labs with a completed requisition form available at: http://www.rockefeller.edu/labheads/auerbach/documents/DEB_Requisition_forms.pdf.  Please contact the UVa Cytogenetics Laboratory at 4-5184 for preparation of alternative specimens (CVS, amniocytes, or fibroblasts).

Centralized Prices Estimates

The UVa Health System has implemented a centralized system for pricing information.  Pricing information for both hospital and physician services are provided by contacting 434-243-7283 or via e-mail at UVAHSPRICE@virginia.edu.  This service does not provide pricing information for grants or research project.  For UVa Medical Laboratories, grant and research pricing information is available from Cavell Kopetzky at 434-924-2649.

Genetic Testing and Insurance Carrier Pre-Authorization

Please note that tests that could be considered "genetic testing" may require insurance carrier pre-authorization.  Failure to receive such pre-authorization may result in your patient receiving a bill from Patient Financial Services if the insurance carrier refuses payment.  Among those tests where this is an issue:

Factor V (Leiden)                                                         Factor II

HLA Typing for reasons other than transplant           Fragile X

Hemochromatosis by PCR                                         Cystic Fibrosis

Cytogenetic abnormalities

Any test for cancer, neurologic disorders, etc., associated with a mutation of the genome (FISH, sequencing, etc.)

JAK2 (Janus Kinase 2 Tyrosine Kinase) Mutation Testing available in-house

Effective July 1, 2006, the Molecular Diagnostics Laboratory is offering JAK2 mutation analysis on whole blood and bone marrow aspirates using real time PCR with FRET probe identification.  The mutation is found in the vast majority of cases of polycythemia vera (~90%) and to a lesser extent in essential thrombocythemia and chronic idiopathic myelofibrosis (~50%).  The mutation is not found in CML, lymphoproliferative disorders, or in patients with reactive cytoses.  This test is useful in the workup of patients with unexplained erythrocytosis, thrombocytosis, or granulocytosis.

Whole blood and bone marrow collected in a lavender toped tube (EDTA) are the acceptable specimen types.

Blood Bank Typenex Armband Update

Red Typenex Armbands are still on backorder from Baxter.  Green Typenex armbands (also supplied by Baxter) are the current substitute.  Green Typenex bands are to be used for inpatient and outpatient samples with routine three-day expirations.  Red and Green Typenex Armbands may be used interchangeably.  Yellow Typenex bands are still to be used for outpatient pre-admit surgery patients that fit the blood bank requirements for extended sample dating.

PLEASE NOTE:  OUR INSTITUTION'S BLOOD COLLECTION PROCEDURE HAS NOT CHANGED.

Although the armbands have a prompt for "PB initials," the Blood Bank still requires the first initial and full last name of the phlebotomist to be recorded on the armband.

Any clinician submitting a sample without first initial and full last name of the phlebotomist on the label will be required to come to the Blood Bank to sign the specimen before testing can be completed.

Clinicians should write directly over/on top of the watermark prompts on the armbands rather than around or beside them.  The colored label code should be placed at the top (cap-end) of the tube.

As always, please never use gel pens on the Typenex band labels.  They smear easily and are often illegible by the time the sample reaches the Blood Bank.

Thank you for your attention to these details.

UVA Transfusion Guidelines available in CareCast

Transfusion guidelines are available to all house staff on CareCast and include information such as:

  • how to recognize and respond to types of transfusion reactions
  • infectious disease risks of transfusion
  • indications for irradiated, CMV reduced-risk, leukocyte reduced, and hemoglobin S negative products
  • general dose/expected response profiles for different blood products

To access UVA Transfusion Guidelines:

  1. Log onto CareCast.
  2. Click "Clinical Pathways" on far left menu.
  3. Click "UVAHS Clinical Practice Guidelines & Clinical Protocols" in middle of page.
  4. Scroll down menu to click "Transfusion/Transfusion Reaction Cards."

Antibiotic Susceptibility cards for 2005

Antibiotic Susceptibility cards for 2005 are available for distribution.  Please call 924-8059 to request pocket cards for Inpatient and Outpatient antibiograms.

CSF for culture of acid fast bacteria

Effective August 1, CSF specimens will only be accepted for culture of acid fast bacteria (Mycobacterium spp. and Nocardia spp.) in consultation with and approval by the Microbiology Director-on-Call (PIC 1221).  Of 1005 CSF specimens cultured for these organisms at UVA during the past five years, zero were positive.  An alternative test is PCR, which must be sent to our referral laboratory. However, the sensitivity of that test is similar to culture and is therefore unlikely to provide diagnostic value.

CSF Fungal Cultures to be replaced by Cryptococcal Antigen test

Fungal cultures of CSF will only be accepted after consultation with and approval by the Microbiology Director-on-Call (PIC 1221) effective August 1.  This change is due to the negligible yield of culture on this specimen type.

If a clinician suspects a patient has cryptococcal meningitis, it is recommended that a cryptococcal antigen titer be requested prior to requesting culture. CSF specimens with negative titers are highly unlikely to yield positive cultures.  If a positive titer is obtained and the initial culture is positive, subsequent cultures may be valuable to help monitor antifungal efficacy.  A consultation with Infectious Disease or the Microbiology Director-on-Call is recommended in these cases.

India ink stain for Cryptococcus species in CSF is discontinued

Due to the poor sensitivity of the India ink stain for Cryptococcus species in CSF, this test will be discontinued effective Aug. 1, 2006.  The cryptococcal antigen titer assay is performed daily and is superior to the India ink test for the diagnosis of cryptococcal meningitis.  Cryptococcal antigen tests can be ordered through MIS, CareCast or on the Outpatient Test Request form.

Susceptibilities for Candida species now available in house

Beginning August 1, 2006, the Clinical Microbiology Laboratory is pleased to announce the availability of antifungal susceptibility testing for Candida species.  Fluconazole, itraconazole and 5-fluorocytosine (5-FC) minimal inhibitory concentrations (MIC) will be assessed using an FDA approved panel. Azole MIC interpretations will be reported as susceptible, susceptible-dose dependent (S-DD), and resistant.  S-DD indicates that the organism is susceptible to the drug if maximum drug concentrations in blood are achieved.  5-FC MIC interpretations will be reported as susceptible, intermediate and resistant.  The test is available only upon request by calling 4-LABS.

Please note that antifungal profiles of yeast species vary little from year to year. Currently, nearly 98% of C. albicans species at UVA are susceptible to fluconazole.  Less than 15% of C. glabrata isolates are resistant to fluconazole.  The Clinical Microbiology Laboratory will continue to monitor resistance rates annually.

Fecal Leukocyte Stain to be discontinued

Due to poor sensitivity of the Fecal Leukocyte Stain, this test will no longer be available as of September 1, 2006.  In multiple studies, the Fecal Lactoferrin Test was found to be a more sensitive test and offered optimal negative predictive value, even in breast-fed children.  While breast feeding lowers the specificity of the test, it does not affect the sensitivity.  Other factors that require consideration when evaluating the specificity of the assay include non-infectious causes of inflammation and colonic inflammation caused by frequent exposure to infectious and parasitic agents in children from developing countries.  The Fecal Lactoferrin Test can be ordered through MIS, CareCast or on the Outpatient Test Request form.

Approved Specimen Types for Point of Care Glucose Testing

All glucose meters and tests must be approved by the FDA.  The FDA has not approved any glucose meter, including the Accu-Chek and Inform instruments in use at UVa, for testing with a blood sample from the earlobe.  Approved blood sample sites for glucose testing with the UVa instruments are:

  • Capillary whole blood finger stick
  • Capillary whole blood heel stick
  • Whole blood venipuncture
  • Whole blood from an existing line when the line is properly flushed to remove heparin and/or IV fluids

Point of Care Testing: Use of Another Individual's Badge

Federal regulations require that all testing performed for patient care be traceable to the instrument used and operator of the instrument for any specific test result.  It is for this reason that much of the Point of Care Testing equipment requires an operator to wand their badge and/or enter their employee ID number to access an instrument.  Use of any ID other than one's own is in violation of federal regulation and is considered fraud.  Please refer to Health System Policy 0163 on the consequences of misuse of an ID.

University of Virginia Medical Laboratories Reflex Testing and Procedure Chart

UVa Medical Laboratories perform and bill two types of reflex tests:  Standard Reflex Tests and Mandatory Reflex Tests. The Standard Reflex Test option allows the physician the choice of not ordering the reflex test. The Mandatory Reflex Test option will automatically generate a request for additional testing if the result(s) of the initial test(s) meet or fall outside certain ranges unless the requesting clinician specifically states that he/she does not want the reflex test(s) performed. These ranges have been predetermined based on specific medical criteria and are consistent with best medical practices.  The full list of reflex tests can be found at: http://www.healthsystem.virginia.edu../compliance/mlcp0017.html.