August 2022: Changes to C Telopeptide, Beta Cross Linked (CTELO)

Effective September 6, 2022

C Telopeptide, Beta Cross Linked (CTELO)

Specimen Requirements
Reference Ranges

Changes to Specimen Requirements

Specimen Type:
Serum

Volume:
1 mL

Minimum Volume:
0.5 mL

Collection Container:
Gold Serum Separation Tube (SST)

Transport Temperature:
Frozen, critical

A morning fasting specimen is preferred.

Separate specimens must be submitted when multiple tests are ordered.

Collection Information:
Allow the tube to sit for 15-20 minutes at room temperature to form a clot. Centrifuge and separate serum from cells ASAP or within 2 hours of collection. Transfer serum to a standard aliquot tube.

Alternative Specimen

Alternative Specimen Type:
Plasma

Volume:
1 mL

Minimum Volume:
0.5 mL

Collection Container:
Lavender K₂EDTA Tube

Transport Temperature:
Frozen, critical

Do not draw serum gel tubes for this test.

Collection Information:
Centrifuge and separate plasma from cells ASAP or within 2 hours of collection. Transfer plasma to a standard aliquot tube.

Reference Ranges

Changes to Reference Ranges

Male

6 Months to 6 Years:
500 – 1700 pg/mL

7 to 9 Years:
522 – 1682 pg/mL

10 to 12 Years:
553 – 2071 pg/mL

13 to 15 Years:
485 – 2468 pg/mL

16 to 17 Years:
276 – 1546 pg/mL

18 to 29 Years:
238 – 1019 pg/mL

30 to 39 Years:
225 – 936 pg/mL

40 to 49 Years:
182 – 801 pg/mL

50 to 59 Years:
161 – 737 pg/mL

60 to 69 Years:
132 – 752 pg/mL

70 to 99 Years:
118 – 776 pg/mL

Special Communications

Immediate Test Changes

News & Updates

September 2022: Best Practice for Detecting Hyperhomocysteinemia – Homocysteine Testing—Not MTHFR Genotyping

Best Practice for Detecting Hyperhomocysteinemia: Homocysteine Testing—Not MTHFR Genotyping

There is no conclusive evidence supporting the clinical value of MTHFR polymorphism genotyping.

Practice guidelines from multiple professional societies agree that MTHFR polymorphism genotyping should not be ordered as part of clinical evaluation.

If there is a clinical concern regarding hyperhomocysteinemia, Cleveland Clinic Laboratories recommends Homocysteine testing (HOMCYS) in place of MTHFR genotyping. Homocysteine testing is less expensive, generates a result more quickly, and provides additional actionable information for patient management.

Best Practice

If there is a clinical concern regarding hyperhomocysteinemia (HCC), Cleveland Clinic Laboratories recommends Homocysteine testing (HOMCYS) in place of MTHFR genotyping

Homocysteine (HOMCYS)

Upcoming Changes

November 15, 2022: MTHFR genotyping (MTHFRM) will no longer be available as a send-out test, even if ordered as a miscellaneous test.

March 16, 2021: Homocysteine testing (HOMCYS) will replace MTHFR genotyping at Cleveland Clinic.

HOMCYS Test Overview

Homocysteine (HOMCYS) Test Details

Test Name

Homocysteine

Test Code

HOMCYS

CPT Code

83090

Performing Laboratory

Cleveland Clinic Laboratories

FDA Compliance

In Vitro Diagnostic (IVD)

Methodology

Enzymatic

Days Performed

Sun – Sat

Turnaround Time

8 hours

Specimen Requirements

Type:
Plasma

Volume:
1 mL

Specimen Container:
Light Green Lithium Heparin Plasma Separator Tube (PST)

Transport Temperature:
Refrigerated

Place specimen on ice after draw.

Alternative Specimen Requirements

Type:
Serum

Volume:
1 mL

Specimen Container:
Gold Serum Separation Tube (SST)

Transport Temperature:
Refrigerated

Place specimen on ice after draw.

Special Instructions

• Centrifuge and separate plasma/serum from cells less than one hour after collection.

• If collected in a non-gel separator tube, centrifuge and transfer plasma/serum to a CCL tube and refrigerate.

Stability

Ambient:
4 days

Refrigerated:
4 weeks

Frozen:
10 months

Reference Interval

18-99 Years – Normal:
<15.1 umol/L

MTHFR: Lack of Evidence

Lack of Evidence for MTHFR Polymorphism Genotyping

Recommendation: Test Plasma Homocysteine Levels

Download this Overview (PDF)

There is no conclusive evidence supporting the clinical value of MTHFR polymorphism genotyping.

If there is a clinical concern regarding hyperhomocysteinemia, Cleveland Clinic Laboratories recommends Homocysteine (HOMCYS) testing.

• Multiple practice guidelines agree that MTHFR polymorphism genotyping should not be ordered as part of a clinical evaluation.

• A cheaper, faster, and more accurate way to test for hyperhomocysteinemia is to measure plasma homocysteine levels.

• If plasma homocysteine levels are high, patients can supplement with vitamins such as B6, B12, folate, and folic acid.

• If plasma homocysteine levels are normal, no treatment is indicated—even if there is an MTHFR variant.

Plasma homocysteine levels determine clinical management, regardless of the MTHFR genotype result.

Professional Societies with MTHFR Polymorphism Testing Guidelines:

After reviewing these guidelines,
Cleveland Clinic’s RT-PLMI Section of Molecular Pathology, Genomic Medicine Institute, and Laboratory Stewardship Committee agreed to discontinue MTHFR polymorphism genotyping.

Background

The MTHFR gene (OMIM: 607093) on 1p36.22 encodes the 5,10-methylenetetrahydrofolate reductase enzyme, which converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, the primary circulatory form of folate. This enzyme is also involved in the metabolism of the amino acid, homocysteine. A deficiency of the enzyme can lead to HHC.

Polymorphisms are common variants within a gene that do not necessarily affect its function, unlike pathogenic or disease-causing variants. Two commonly tested polymorphic variants in MTHFR are:

c.665C>T* (p.Ala222Val)
*Historically referred to as C677T, the ‘thermolabile’ variant

c.1286A>C (p.Glu429Ala)

These variants are so common that approximately 25% of individuals with Hispanic ancestry and 15% of North Americans with European ancestry have two copies of c.665C>T.

The presence of two copies of c.665C>T (homozygosity) may result in decreased MTHFR enzyme activity and mild HHC. Neither of these MTHFR polymorphisms causes severe MTHFR deficiency (<20% enzyme activity).

References

1. Lack of Evidence for MTHFR Polymorphism Testing. ACMG Practice Guideline. Genet Med. 2013;15(2):153-6.
2. Inherited Thrombophilias in Pregnancy. ACOG Practice Bulletin. No. 197. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2018;132:e18–34.
3. Levin BL, Varga E. MTHFR: Addressing Genetic Counseling Dilemmas Using Evidence-Based Literature. J Genet Counsel. 2016;25:901-11.
4. Choosing Wisely® Initiative https://www.choosingwisely.org/
5. Eng, C. A Genetic Test You Don’t Need: Testing MTHFR is usually unnecessary. Cleveland Clinic Health Essentials. https://health.clevelandclinic.org/a-genetic-test-you-dont-need/. Accessed November 19, 2020.

Updating Best Practices

Cleveland Clinic Laboratories encourages providers to incorporate Homocysteine testing (HOMCYS) into their practice in place of MTHFR genotyping.

November 15, 2022: MTHFR genotyping will no longer be available as a send-out test, even if ordered as a miscellaneous test.

March 16, 2021: MTHFR genotyping will no longer be performed in-house at Cleveland Clinic.

Special Communications

Immediate Test Changes

News & Updates

Pathology Insights: Update on Small Round Cell Tumors with Scott Kilpatrick, MD

Pathology Insights Video Series

Update on Small Round Cell Tumors with Scott Kilpatrick, MD

Presented by Scott Kilpatrick, MD

In this video, Scott Kilpatrick, MD, Director of Orthopedic Pathology at Cleveland Clinic, provides historical context and WHO updates on the evolving classification of undifferentiated round cell sarcomas, including Ewing sarcoma and the so-called Ewing family of sarcomas.

**As part of our educational mission for our clients and communities, Cleveland Clinic Laboratories presents the Pathology Insights video series.**

These short videos break down information about interesting pathology cases to better inform doctors, laboratory staff, patients, or anyone interested in the field of pathology. Each episode features important cases, methods, and practices that are personally presented by our staff pathologists.

July 2022: Test Delay – Testosterone, Total and Free, Serum (TFTEST)

Immediate Test Change

Test Delay – Testosterone, Total and Free, Serum (TFTEST)

Effective July 18, 2022.

Delayed Test

Testosterone, Total and Free, Serum (TFTEST)

Send-out Testosterone, Total and Free, Serum (TFTEST) testing performed at Mayo Clinic Laboratories is currently delayed for approximately three weeks.

At this time, Mayo Clinic Laboratories does not have an estimate for when turnaround time will return to the expected value of four to six days.

Note:
Specimens are stable for 60 days when frozen.

Alternative Tests

Bioavailable Testosterone, SHBG, Adult Male (BTESTO)

In-house test for total testosterone by immunoassay and calculated bioavailable testosterone for adult males.

Bioavailable Testosterone/SHBG, Female & Child (BTSTFC)

Send-out test for total testosterone by LC-MS/MS and calculated bioavailable/free testosterone for children and adult females.

Special Communications

Immediate Test Changes

News & Updates

July 2022: Changes to Sulfonylurea Hypoglycemics (SULFON)

Special Communication

July 2022: Changes to Sulfonylurea Hypoglycemics (SULFON)

Effective July 5, 2022

Sulfonylurea Hypoglycemics (SULFON)

Specimen Requirements

Changes to Specimen Requirements

Specimen Type:
Serum

Volume:
1 mL

Minimum Volume:
0.3 mL

Collection Container:
Red (Serum) No Additive Tube

Transport Temperature:
Frozen

Do not draw serum gel tubes for this test.

Additional Info:
Centrifuge and aliquot ASAP or within 2 hours of collection.

Separate specimens must be submitted when multiple tests are ordered.