There are no official guidelines to assist in answering this question. I will search for relevant research papers instead.
From the Research
Fibromyalgia and Antinuclear Antibody (ANA) Test
- Fibromyalgia is a musculoskeletal disorder characterized by generalized myalgias, arthralgias, and widespread tender points, and it is frequently accompanied by fatigue, stiffness, and a nonrestorative sleep pattern 1.
- A subset of people with fibromyalgia test positive for the antinuclear antibody (ANA) and have constitutional symptoms that resemble those of patients with early lupus 1.
- Studies have shown that approximately 30% of fibromyalgia patients are ANA-positive, with a 75% preponderance of the speckled pattern and 20% diffuse pattern 1.
Prevalence of Positive ANA in Fibromyalgia Patients
- The prevalence of positive ANA in fibromyalgia patients has been reported to be around 8.8% to 11.8% in different studies 2, 3.
- One study found that the ANA-positive rate was 12/137 (8.8%) in fibromyalgia patients and 20/225 (8.9%) in osteoarthritis patients, with all ANA positivity being at a low titre 3.
Relationship Between ANA Positivity and Fibromyalgia Symptoms
- Studies have shown that ANA-positive fibromyalgia patients do not have a significantly different symptom profile compared to ANA-negative patients 1, 2.
- However, one study found that fibromyalgia patients with photosensitivity or Raynaud phenomenon had higher anxiety, depression, and somatic symptom scores, regardless of ANA positivity 2.
Predictive Value of ANA for Connective Tissue Disease
- The predictive value of ANA for connective tissue disease in fibromyalgia patients is low, with one study finding that only one patient out of 12 ANA-positive fibromyalgia patients developed systemic lupus erythematosus (SLE) over a 2-4 year follow-up period 3.
- Another study found that fatigue was common in ANA-positive individuals lacking sufficient criteria for a systemic autoimmune rheumatic disease (SARD) diagnosis, and did not predict imminent disease progression 4.