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

LABORATORY MEDICINE UPDATE November 12, 2014

Heparin Induced Platelet Antibody Assay - clarification

Heparin Induced Thrombocytopenia (HIT) is caused by heparin-dependent antibodies formed to the heparin/platelet factor 4 complex. These antibodies are initially formed when a patient has been on heparin therapy for five or more days. An immune response to a heparin dose may be observed sooner (1-2 days) if the patient has had previous exposure to heparin. The hallmark symptoms of HIT are a drastic fall in platelet count and thrombosis. Other symptoms may include cutaneous reactions, from a simple allergic reaction to lesions to necrosis. Guidelines for assessment and treatment of HIT and HITTS are available through the Clinical Portal at: http://www.healthsystem.virginia.edu/pub/anticoagulationtherapy/intranet/protocols.html.

Analysis for the presence of the antibody is now being performed by Medical Labs in the Special Coagulation section. Testing is performed 7 days a week from 7 AM to 3:30 PM, although samples may be submitted at any time. All positive results will automatically be confirmed by the Serotonin Release Assay performed by the Blood Center of Wisconsin so a separate order for this test should not be placed. The specimen type is 5 mL blood in a red-top tube and should be submitted to the Core Lab immediately after venipuncture.

Return of Abbott PTH Assay

Effective November 17, 2014, the PTH assay on the Abbott Architect analyzer will be reinstituted. The assay became unavailable in February 2014 and was temporarily replaced with the Immulite assay (previously used at UVA 2006-2011). The Immulite assay will no longer be used routinely.

Serum PTH results with the Abbott assay will be approximately 40% higher than with the Immulite assay. For patients who were monitored since February 2014 with the Immulite assay, PTH testing will be performed by both assays as needed, with no charge for the Immulite assay. To arrange no-cost retesting, contact Dr. Dede Haverstick at [email protected].

The reference interval for the Abbott assay is 8-77 pg/mL.

Page 1 of 4 Heparin PTT

Effective November 5, 2014 the Clinical Laboratory will be notifying the nurse taking care of the patient when there is a specimen integrity problem for Heparin PTTs ONLY.

Reasons for calling nursing staff include  Quantity not sufficient for analysis  Hemolysis  Contamination/questionable results

The policy, which applies to in-patients only, was put into place at the request of the Anticoagulation Committee and approved by Laboratory Administration.

Cryptococcal Antigen Testing and Fungal CSF Cultures

All CSF specimens testing positive for Cryptococcal Antigen (any titer), will reflex to a Fungal Culture to determine viability of the organism. This reflexive testing will occur automatically and does not require prior approval from the Clinical Microbiology Director on call. All other requests for Fungal Cultures on CSF will continue to require director approval. The Clinical Microbiology Director on call can be reached at PIC 1221.

HCV Viral Load Analysis by the Abbott m2000 RealTime HCV Test

As of September 12, 2014, the Clinical Microbiology and Molecular Diagnostics Laboratory implemented a new method for HCV viral load analysis. The new Abbott m2000 RealTime HCV test provides a broadened dynamic range – from 12 IU/mL to 100,000,000 IU/mL as compared to 43-69,000,000 IU/mL reported previously. Results will read as follows:

 For patients with a viral load at or above the limit of quantification of 12 IU/mL, a numeric value and the log base 10 will be reported.  For patients with no measurable viral load, the result “None Detected” will be reported.  For patients with a detectable but not quantifiable viral load, the results “Virus detected, but quantified at less than 12 IU/mL” and “Virus detected, but quantified at less than 1.08 log base 10” will be reported. This indicates that HCV nucleic acid is present, but a level below the limit of quantification.

Required specimen: Approved specimen type has not changed. Testing requires serum (gold or red top tube). Required volume is 6 mL blood (3 mL serum).

Testing Schedule: HCV viral load testing will be performed twice weekly, as needed to meet the needs of the current caseload.

Please contact the Clinical Microbiology Director on call at PIC 1221 with questions.

Page 2 of 4 Change in testing location – aldosterone and 17-OH progesterone

Due to lack of available reagents, samples for aldosterone and 17-OH progesterone testing will now be sent to Mayo Medical Laboratories for analysis. There are no changes to the specimen types.

BD Affirm VPIII Vaginitis/Vaginosis Panel

The Clinical Microbiology Laboratory is now offering a DNA probe test for detection and identification of Candida species, Gardnerella vaginalis and Trichomonas vaginalis nucleic acid in vaginal fluid specimens from patients with symptoms of vaginitis/vaginosis. This test will detect these organisms at or above clinically significant thresholds, and will replace vaginal culture for bacterial vaginosis in most cases. Culture or PCR for agents of STDs should be ordered separately, based upon the suspected etiology. Bacterial cultures of vaginal samples for agents other than Neisseria gonorrhoeae will require approval by the Clinical Microbiology Director on call. If clinicians suspect vaginal Group A Strep cellulitis, a bacterial culture should be ordered following approval from the Clinical Microbiology Director on call.

Specimens for the Affirm VPIII Vaginitis/Vaginosis Panel are submitted in an Affirm VPIII Ambient Temperature Transport System (ATTS) and are currently available from the Microbiology Laboratory. As test utilization increases, the ATTS will be distributed by the storeroom. Test results will be available in 24 hours or less. For questions or concerns, please contact the Clinical Microbiology Director on call at PIC 1221.

ROTEM® Testing

The Blood Bank is now offering Rotem testing in the Blood Bank Monday-Friday from 9am to 10pm. The Rotem testing is ordered in Epic and samples are tubed to the Blood Bank. A blue- top tube is required and the testing must be done within 4 hours. There are different Rotem tests that can be ordered (see below), and physicians can remotely view the clotting pictograms as well as numeric results using the Secure Viewer software. The Rotem device measures the visco-elastic properties of clot formation and provides a visual record of time to clot formation (CT), time to clot amplitude of 20 mm (CFT), rate of clot formation (α angle and CFT), clot amplitude at 10 minutes (A10), maximum clot amplitude (MCF) and clot lysis (CL) in real time. There are five available tests: INTEM, which uses similar coagulation activators as the intrinsic pathway; EXTEM which uses similar coagulation activators as the extrinsic pathway; FIBTEM which measures the contribution of fibrinogen to clot formation, and thus provides a rapid method for evaluating the adequacy of fibrinogen levels, HEPTEM, which provides a quick method for determining whether heparin has been adequately reversed in a patient on coronary artery bypass; and APTEM which permits

Page 3 of 4 evaluation of fibrinolysis. Current available clotting tests, the PT and aPTT measure only the time required to initiate clot formation, and give no information on other clotting parameters. Thus, ROTEM is a point of care test that has the potential to enable clinical staff to rapidly interpret a bleeding patient’s thromboelastogram and provide targeted blood product therapy to correct coagulopathy; thereby improving patient care and decreasing costs.

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