Anti Merkel Cell Panel

General Information

Lab Name

Lab Code

AMERK

Epic Ordering

Anti Merkel Cell Panel

Description

All samples include testing for antibodies to the Merkel Cell Carcinoma (MCC) oncoprotein. In addition, screening for the Merkel cell polyomavirus VP1 capsid antibody is done once, on the first sample ordered for AMERK testing (AMERK2) and billed separately. The VP1 capsid antibody test is reflexively added to the order by the laboratory.

SmT oncoprotein antibodies are present in the blood of 50% of patients when they have clinically detectable Merkel Cell Carcinoma (MCC). In patients who make oncoprotein antibodies, titers are expected to decrease significantly within 3 months of successful treatment of MCC. Changes in oncoprotein titers of less than 25% may not be biologically significant. A significant rise in titer or stabilization above 2000 STU may be associated with persistent or recurrent MCC.

References

1. Paulson et al., Antibodies to Merkel Cell Polyomavirus T Antigen Oncoproteins Reflect Tumor Burden in Merkel Cell Carcinoma Patients, Cancer Research (2010) 70:8388.

2. Paulson et al., Viral Oncoprotein Antibodies as a Marker for Recurrence of Merkel Cell Carcinoma: A Prospective Validation Study, Cancer (2017) 123:1464.

Synonyms

AMEKR2, MCC, MCPyV, Merkel cell carcinoma, polyomavirus oncoprotein antibodies, polyomavirus VP1 capsid antibody, small T antibodies

Components

Code	Name
MCSTT	Merkel Oncoprotein Ab Titer
MCSTI	Merkel Oncoprotein Ab Interp
MCSTT2	Prior Merkel Oncoprotein Ab
MCPREV	Date of Prior Sample
MCDSI	Merkel Disease Status Interp 1
MCDSI2	Merkel Disease Status Interp 2
MCMTH1	Merkel Anti SmT Method

Interpretation

Method

Laboratory developed Luminex paramagnetic bead, multiplex assay

Reference Range

See individual components

Ref. Range Notes

Established by testing of 104 normal blood donors.

Interferences and Limitations

Lipemia may increase results 15-20% (in procedure)

Screening for the Merkel cell polyomavirus VP1 capsid antibody is done once, on the first sample ordered for AMERK testing (and billed separately). This assay is used to screen Merkel Cell Carcinoma (MCC) patients for current or prior infection with the Merkel cell polyomavirus. Patients who lack these antibodies should not be monitored with additional AMERK testing because they do not make antibodies to the viral oncoprotein and should be monitored by other means. VP1 capsid antibodies are not an indicator of disease activity.

Guidelines

Specialty Testing in Immunology

Ordering & Collection

Specimen Type: Blood
Collection: 6 mL blood in RED TOP or SST tube
Forms & Requisitions: AMERK requisition
Handling Instructions: Centrifuge and separate serum within 4 hours of collection.

Stability: Temperatures up to 26°C: 7 days; Frozen at -20°C: Long Term
Quantity: requested: 2 mL serum
minimum: 0.5 mL serum

Processing

Processing: Centrifuge and separate serum within 4 hours of collection.

SPS: Refrigerate serum. Send copy of the requisition to Immunology.

Stability: Temperatures up to 26°C: 7 days; Frozen at -20°C: Long Term

Performance

LIS Dept Code

Immunology (IMM)

Performing Location(s)

UW-MT	Immunology 206-520-4600 Clinical Lab, Room NW220, University of Washington Medical Center, 1959 NE Pacific street, Seattle, WA 98195

Frequency

Set-up on Mondays, Results available in 3-4 weeks.

Available STAT?

Billing & Coding

CPT codes: 0058U
LOINC: 18727-8
Interfaced Order Code: UOW4539