Background

CKMB is an antiquated cardiac marker due to its limited clinical utility. Current guidelines recommend cardiac troponin testing as the biomarker of choice for myocardial injury due to its superior specificity and sensitivity. Additionally, co-testing with CKMB and troponin adds no incremental value.  

This is supported by the American College of Cardiology (ACC), European Society of Cardiology (ESC), Association for Diagnostics & Laboratory Medicine (formerly AACC), American Society for Clinical Pathology (ASCP), Cleveland Clinic’s Cardiovascular Medicine Division, Clinical Biochemistry Section, and Laboratory Stewardship Committee. 

References

• Fourth Universal Definition of Myocardial Infarction (PMID: 30571511) 
• Eliminating CKMB Testing in Suspected ACS: A Value-Based Quality Improvement (PMID: 28806444) 
• ESC Study Group on Cardiac Biomarkers of the Association for Acute CardioVascular Care: A Fond Farewell at the Retirement of CKMB (PMID: 33486520)

Test Name

Alzheimer’s Disease Biomarker Panel, Cerebrospinal Fluid

Test Code

ALZCSF

CPT Codes

83520 – QTY (3)

Methodology

Electro Chemiluminescence Immunoassay (ECLIA)

Specimen Requirements

Type:
Cerebrospinal fluid (CSF)

Volume:
2.5 mL

Container:
CSF Transport Tube, 2.5 mL (Sarstedt)

Collection Instructions

1. Confirm that the tube type is correct – only a specimen collected in the Sarstedt CSF Transport Tube [ref. 63614.625] is acceptable.
2. Perform a lumbar puncture using the gravity drip collection method (preferred). Do not use the first 2 mL of CSF.
3. Collect CSF directly into the tube up to the fill line.
4. Inspect the sample for the presence of blood. Do not use CSF samples that appear reddish. Instead, collect additional clear (non-hemolytic) CSF in a new CSF tube.
5. Do not process the sample before sending it to the laboratory (i.e., do not invert, transfer, or aliquot).

Rejection Criteria

CSF collected in polystyrene or glass tubes

Bloody or hemolyzed specimens.

Unfilled tubes.

Stability

Ambient:
5 days

Refrigerated (preferred):
14 days

Frozen:
8 weeks (-20⁰C)

Days Performed

Days Performed
Once a week

Reported
1-8 days

Reporting

Component

p-Tau181/Abeta42

Total-Tau/Abeta42

p-Tau181

Total-Tau

Abeta42

Reference Interval

≤0.0230

≤0.280

≤31.3 pg/mL

≤375.4 pg/mL

≥564.2 pg/mL

Clinical Information

A negative p-Tau181/Abeta42 ratio and/or Total-Tau/Abeta42 ratio is consistent with a negative amyloid positron emission tomography (PET) scan and reduces the likelihood that a patient’s cognitive impairment is due to Alzheimer’s disease.

A p-Tau181/Abeta42 ratio and/or Total-Tau/Abeta42 ratio elevated above the cut-off is consistent with biological changes associated with Alzheimer’s disease (AD) and a positive amyloid positron emission tomography (PET) scan. A positive result does not establish a diagnosis of AD or other cognitive disorders and should be interpreted as an adjunct to other clinical diagnostic information.

The ratios will not be calculated in samples with an Abeta42 concentration >2,500 pg/mL. This result is consistent with a negative amyloid positron emission tomography (PET) scan and reduces the likelihood that a patient’s cognitive impairment is due to Alzheimer’s disease.

The p-Tau181, Total-Tau, and Abeta42 tests are not intended to be used as a stand-alone test in spinal fluid. For interpretation of results, refer to the p-Tau181/Abeta42 and Total-Tau/Abeta42 ratios.

The test method is the Elecsys electrochemiluminescence immunoassay manufactured by Roche Diagnostics. Values determined by different assay methods cannot be used interchangeably.

The validity of this test interpretation requires strict adherence to the specimen collection and preparation instructions detailed in the Cleveland Clinic’s Test Directory.

Targeted Oncology Panel by NGS

Order Codes
TOPTO (FFPE Tissue)
TOPCY (Cytology Alcohol or Formalin fixed cell block)
TOPBM (Bone Marrow Aspirate)
TOPPB (Peripheral Blood)

This test requires 5-10% tumor purity and does not evaluate circulating tumor DNA.

CPT Code
81445

Methodology
Next-Generation Sequencing

Specimen Type
FFPE Tissue
• 15 charged, unbaked, and unstained slides sectioned at 7 μm.
• One pre and one post H&E slide with tumor area circled, and percent rumor indicated.

Cytology
• 15 charged, unbaked and unstained slides sectioned at 7 μm.
• One H&E slide with tumor percent indicated.

Bone Marrow Aspirate
• 2 mL, Lavender K₂EDTA Tube

Peripheral Blood
• 4 mL, Lavender K₂EDTA Tube

Days Performed
2–3 times per week

Turnaround Time
8 days

Overview

Single nucleotide variants (SNVs), small insertions and deletions (indels), copy number gains, select fusions, and aberrant transcripts evaluated by this assay can aid in the diagnostic and therapeutic assessment of a variety of tumor types, including non-small cell lung cancer, melanoma, colorectal cancer, prostate cancer, breast cancer, glioblastoma, thyroid cancer, and others.

This panel can also provide focused tumor profiling for patients with locally advanced/metastatic disease, who are candidates for anti-cancer therapy, to identify uncommon but targetable alterations. In particular, this panel can be utilized for small biopsies and cytology specimens that may not be amenable to more comprehensive genomic sequencing.

Targeted Genes & RNA Fusions

For a full list of targeted genes & RNA fusions, please refer to the Targeted Oncology Panel by Next-Generation Sequencing Technical Brief.

How to Order

Place an order through an electronic interface or complete a Molecular Oncology & Associated Biomarkers Requisition and submit it with the specimen(s).

Hot Spot Panel Discontinuation

The TOP NGS panel will replace solid tumor hotspot mini-panels (Lung, Colorectal, Melanoma, GIST, etc.), as all previously detected biomarkers are included in the new testing.

In situations where the mini-panels were previously used as part of an upfront diagnostic workup, pathologist diagnostic and reflex ordering will utilize TOP testing.