Browsing Tag

May 2017

Compliance & Safety, Toxicology

Urgent Notice: Lead Testing

On May 17, 2017, the US Food and Drug Administration (FDA) issued a safety communication warning against using venous samples on Point of Care Magellan Diagnostics LeadCare Testing System devices (LeadCare, LeadCare II, LeadCare Plus, and LeadCare Ultra). Venous specimens appear to be at risk for having falsely low results.  Only Capillary (“finger stick” or “heel stick”) specimen types should be used.

IF YOUR OFFICE IS USING ANY OF THE MAGELLAN LEADCARE TESTING SYSTEM DEVICES: please DISCONTINUE the use of VENOUS specimens for testing. Continue Reading

Immunochemistry, Test Utilization

Utility of specific IgE (sIgE) testing to foods and food allergen components

The diagnostic evaluation of allergic disease occurs in the context of a patient’s complete clinical presentation. Important factors include, age, clinical signs and symptoms, relevant allergen exposures, and the performance characteristics (sensitivity, specificity, and predictive values) of the allergy tests themselves. Allergy tests yield information about sensitization to allergens, which is not always equivalent to allergic hypersensitivity (i.e., sensitivity); thus, interpretation in the context of clinical history is essential for accurate diagnosis. Continue Reading

Chemistry, Referral/Sendouts, Test Utilization

Appropriate Thyroglobulin Tumor Marker and Anti-Thyroperoxidase Ordering Practices

Thyroid Peroxidase Antibody (anti-TPO), Blood Level (Test #8524 )
This is the recommended test for the evaluation of Autoimmune Thyroiditis

Thyroglobulin, Tumor Marker, Serum (Test #3069)
It is only indicated for monitoring of thyroid cancer treatment.
This result is reported with an Anti-Tg result to assess for possible interference.
This test should NOT be ordered for associated anti-Tg result provided by reference laboratory.

Thyroglobulin Antibody (anti-Tg) Test
Historically ordered with anti-TPO for evaluation of possible autoimmune thyroiditis.
The literature shows that anti-TPO, alone, has better sensitivity and specificity with only 5% of cases of Autoimmune thyroiditis with anti-TPO negative, anti-Tg positive.
Since 2/2011, requests for anti-Tg have been cancelled per Laboratory Communication: Memo Thyroglobulin Antibody 2/2011

Spectrum Health Regional Laboratory Experience February 2015 – March 2016 (13 months):
357 patients with both Anti-TPO and Anti-Tg results.
*Anti-Tg results were due to concomitantly ordered Thyroglobulin TM requests.
250 patients had positive Anti-TPO and/or Anti-Tg level
193 patients had both positive Anti-TPO and Anti-Tg level
56 patients had positive Anti-TPO and negative Anti-Tg level
1 patient had a negative Anti-TPO and positive Anti-Tg levels

Based on these results, and what is reported in the literature, we are confident of our current practices and strongly request discontinuation of Thyroglobulin TM requests for the associated Anti-Tg result

Caturegli P, De Remigis A, Rose NR. Hashimoto thyroiditis: clinical and diagnostic criteria. Autoimmun Rev. 2014 Apr-May;13(4-5):391-7