Immunology

Anti-Jo-1 Antibody

Normal Range
< 1.0 Index (Negative)
Sample Type
Standard
Fasting
No
Unit
Index

The Anti-Jo-1 antibody targets histidyl-tRNA synthetase and is a hallmark marker within the ANA Profile (ENA Panel). It is specifically associated with Anti-Synthetase Syndrome, a subset of idiopathic inflammatory myopathies (IIM). Its presence is strongly predictive of polymyositis or dermatomyositis, often accompanied by interstitial lung disease (ILD), Raynaud's phenomenon, and 'mechanic's hands'. Screening for this is vital when a patient presents with unexplained proximal muscle weakness and pulmonary symptoms.

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Interactive
Index

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

While highly specific for anti-synthetase syndrome, a negative Jo-1 does not rule out inflammatory myopathy, as several other anti-synthetase antibodies (like PL-7 or PL-12) exist but aren't always included in standard screens. Furthermore, false positives can occur in rare cases of chronic viral infections, requiring clinical correlation with muscle biopsy or EMG.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Anti-Jo-1 Antibody:

Related Indicators

DR

Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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