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Epic Test Code LAB770 Jo 1 Antibodies, IgG, Serum

Additional Codes

MML Code: JO1

LIS Code: JO1A

NY State Approved

Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Jo 1 Ab, IgG, S

Method Name

Multiplex Flow Immunoassay

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 21 days
  Frozen  21 days


Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL


Specimen Type

Serum

Specimen Minimum Volume

0.35 mL

Reference Values

<1.0 U (negative)

≥1.0 U (positive)

Reference values apply to all ages.

Analytic Time

1 day

Day(s) and Time(s) Performed

Monday through Saturday; 4 p.m.

CPT Code Information

86235

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

NA

Cautions

A negative test for Jo 1 antibodies does not exclude the diagnosis of polymyositis or dermatomyositis.

Interpretation

A positive result for Jo 1 antibodies is consistent with the diagnosis of polymyositis and suggests an increased risk of pulmonary involvement with fibrosis in such patients.

Specimen Retention Time

14 days

Testing Algorithm

See Connective Tissue Disease Cascade (CTDC) in Special Instructions.

Useful For

Evaluating patients with signs and symptoms compatible with a connective tissue disease, especially those patients with muscle pain and limb weakness, concomitant pulmonary signs and symptoms, Raynaud phenomenon, and arthritis

 

Testing for antibodies to Jo 1 is not useful in patients with a negative test for antinuclear antibodies.

Clinical Information

Jo 1 (histidyl tRNA synthetase) is a member of the amino acyl-tRNA synthetase family of enzymes found in all nucleated cells. Jo 1 antibodies in patients with polymyositis bind to conformational epitopes of the enzyme protein and inhibit its catalytic activity in vitro.(1)

 

Jo 1 antibodies are a marker for the disease polymyositis, and occur most commonly in myositis patients who also have interstitial lung disease. The antibodies occur in up to 50% of patients with interstitial pulmonary fibrosis and symmetrical polyarthritis.(2)

 

See Connective Tissue Disease Cascade (CTDC) in Special Instructions.