Overview


This test assists in the diagnosis of autoimmune myasthenia gravis (MG).

Test code:

MuSK RIPA

Abbreviations:

MuSK Ab; MuSK RIPA

Methodology

In-house radioimmunoprecipitation assay

Validation:

Laboratory developed test (LDT)

Requirements


Specimen type:

Serum

Minimum volume:

0.5 mL

Preferred volume:

3 mL

Rejection criteria:

Grossly hemolytic, lipemic, or icteric. If the sample arrives at room temperature.

Specimen


Specimen collection:

• No patient preparation required before collection.
• 5 mL SST tube (gold-top)
• Spin tubes, aliquot serum, and ship on cold-packs same day

Specimen handling:

Centrifuge SST tubes at 1800 - 2200 x g for 10-15 minutes
Draw off serum (top layer) into Aliquot tubes with pipette, ensuring not to take gel or RBC (middle/bottom layers)
Store Aliquot tubes in refrigerator (2°C - 8°C) until shipping.

Specimen stability:

Serum samples may be stored:
Up to 7 days refrigerated (2 – 8⁰C )
-20⁰C for longer term storage – avoid subsequent freeze thaws

Performance


Testing frequency:

Once a week (2 day testing procedure)

Turnaround time:

2-8 days

Reference range:

N/A

Additional Information


  • This test was developed and its performance determined by Neurocode USA Inc. It has not been cleared or approved by the Food and Drug Administration.
  • Please indicate if patients are on immunomodulating treatments as these may interfere with testing.
  • Causal antibodies cannot be identified in about 10% of MG cases. Therefore, a positive result is specific for the diagnosis of AChR ab myasthenia gravis (MG), but a negative result does not rule out an MG diagnosis.