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Test ID NMS1 Necrotizing Myopathy Evaluation, Serum

Necessary Information

Include relevant clinical information, name, phone number, mailing address, and e-mail address (if applicable) of ordering physician.

Specimen Required


Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 3 mL

Collection Instructions: Centrifuge within 2 hours and aliquot 2 mL.

Useful For

Evaluating patients with suspected necrotizing autoimmune myopathy


The utilization of this combinatorial immunoassay provides accuracy and speed in diagnosis of necrotizing autoimmune myopathy (NAM). Early diagnosis facilitates better prognosis through initiation of aggressive immune treatments, typically requiring more than 1 agent, and discontinuation of statin medications. Persons without access to specialty muscle biopsy testing services may be afforded an early diagnosis through application of this testing.


Identification of NAM may indicate the presence of a paraneoplastic disorder.

Profile Information

Test ID Reporting Name Available Separately Always Performed
NSI1 Necrotizing Myopathy Interp, S No Yes
SRPIS SRP IFA Screen, S No Yes

Testing Algorithm

This is a focused algorithmic test designed to achieve high sensitivity for identification of antibodies specific for necrotizing autoimmune myopathy (HMGCOA-IgG and SRP-IgG). This test is unique in the market by having an initial screen for signal recognition particle (SRP) antibodies performed using tissue indirect immunofluorescence, which increases clinical sensitivity as compared to SRP immunoblot methodologies.


If indirect immunofluorescence assay (IFA) pattern suggests signal recognition particle (SRP) antibody, SRP IFA titer and SRP54 immunoblot are performed at an additional charge.


See Necrotizing Myopathy Evaluation in Special Instructions.

Method Name

SRPIS, SRPTS: Indirect Immunofluorescence Assay (IFA)

SRPBS: Immunoblot

HMGES: Enzyme-Linked Immunosorbent Assay (ELISA)

Reporting Name

Necrotizing Myopathy Evaluation, S

Specimen Type


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reference Values

3-Hydroxy-3-Methylglutaryl Coenzyme-A (HMG-CoA) Reductase:

<20.0 U/mL


Signal Recognition Particle Antibody Screen:



Signal Recognition Particle Antibody:



Signal Recognition Particle Antibody, Titer:


Day(s) and Time(s) Performed

Signal Recognition Particle Antibody:

Tuesday, Thursday; 2 p.m.


Signal Recognition Particle Antibody Screen:

Tuesday, Thursday, Sunday; 6 a.m.


Signal Recognition Particle Antibody, Titer:

Tuesday, Thursday, Sunday; 6 a.m.


3-Hydroxy-3-Methylglutaryl Coenzyme-A (HMG-CoA) Reductase:

Tuesday, Friday; 6 a.m.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information



86256 (if appropriate)

84182 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NMS1 Necrotizing Myopathy Evaluation, S In Process


Result ID Test Result Name Result LOINC Value
603543 Necrotizing Myopathy Interp, S 69048-7
603540 SRP IFA Screen, S 53010-5
603538 HMG-CoA ELISA, S In Process

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SRPBS SRP Immunoblot, S No No


If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.

Special Instructions