Browsing Category

Referral/Sendouts

Referral/Sendouts

CK Isoenzyme Discontinued

As of March 13th, 2017 Spectrum Health Regional Laboratory will be inactivating the CK Isoenzyme orderable  (SH # 2799, Epic #LAB64).  This test is not necessary in patients with clinically consistent CK elevations such as, but not limited to, muscle disease, muscle injury or statin use. In cases of suspected statin myopathy/myositis, elevated CK coupled with statin use is enough to make the diagnosis. CK Isoenzyme testing is recommended in situations where the CK elevation cannot be explained by clinical history and physical. Moving forward, CK Isoenzyme requests will require approval from either Dr. Alter or Dr. Blue.

Any questions concerning this change may be directed to Dr. David Alter or Dr. Deborah Blue via the “Contact Us” link.

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

Referral/Sendouts, Test Utilization

Thyroglobulin Tumor Marker Evaluation

We are currently evaluating serum Thyroglobulin Tumor Marker test ordering practices as the volume has quadrupled over the last 3 years without a quadrupling of total laboratory volume.

If you order this test, please contact Dr. David Alter with the reason for ordering the test.

Of note, the only stated reason in “UPTODATE” is monitoring for recurrence of medullary thyroid cancer status post treatment.

Options

  1. Monitoring treatment
  2. Serum thyroglobulin as a marker for autoimmune thyroiditis
  3. Serum thyroglobulin ordered for the accompanying anti-thyroglobulin antibody result
  4. Other, please elaborate.