Mayo Clinic Laboratories > Neurology > Autoimmune > Necrotizing autoimmune myopathy

Necrotizing autoimmune myopathy

A targeted and accelerated approach to diagnosis

Immune-mediated necrotizing myopathy (IMNM), also called necrotizing autoimmune myopathy (NAM), is a rare but serious muscle disease strongly associated with autoantibodies to either signal recognition protein (SRP-IgG) or 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR-IgG). Our testing can provide earlier identification and treatment initiation in patients with IMNM, which is critical to preventing further harm.

Necrotizing autoimmune myopathy Test menu

Necrotizing autoimmune myopathy

Key testing


  • A single evaluation with the two most pertinent antibodies associated with IMNM: HMGCR-IgG and SRP-IgG. The combination of both antibodies maximizes clinical sensitivity for diagnosing patients with this disease.
  • Detection of SRP-IgG using a sensitive immunofluorescence-based assay and then confirming by a second immunoblot technology.
  • Antibodies are tested in parallel, providing results in approximately one week.



Fill out the form below and one of our specialists will be in touch.

(BETA) Choose a language to view this content in:
About the translation.