Anti-Ro Antibody

Updated: Sep 29, 2020
  • Author: Niral M Patel; Chief Editor: Eric B Staros, MD  more...
  • Print

Reference Range

Anti-Ro antibodies, also known as anti-SSA antibodies, are associated with Sjögren syndrome.

Anti-Ro antibodies, immunoglobulin G (IgG) [1] :

  • < 1 U (negative)
  • ≥ 1 U (positive) 


A positive anti-Ro result is indicated by a speckled appearance under immunofluorescence with ultraviolet light.

Anti-Ro levels may be elevated in the following conditions: [1]

Both anti-Ro/SSA and anti-La/SSB are usually absent in secondary Sjögren syndrome. [2]

When anti-Ro/SSA levels are elevated in SLE, it is often in antinuclear antibody (ANA)–negative lupus. [2]

Anti-Ro/SSA plus anti-La/SSB is associated with the following factors: [3]

  • Age older than 50 years

  • HLA-DR3

  • Lower likelihood of anti-DNA antibodies

Anti-Ro/SSA without anti-La/SSB is associated with the following factors: [3]

  • Age younger than 22 years

  • HLA-DR2

  • Worse renal manifestations

  • Increased likelihood of anti-DNA antibodies



There are no special collection conditions or timings.

Draw in a standard red-top tube.

Hemolysis and lipemia should not affect the results but should be avoided, if possible.

There are no special storage conditions.

It is usually not part of a laboratory panel.




Anti-Ro antibodies are associated with Sjögren syndrome.

Sjögren syndrome is often characterized by xerostomia and xerophthalmia-type symptoms. A diagnosis of Sjögren syndrome requires a minimum of 3 of the 4 following criteria: [4]

  • Positive Schirmer test result or Rose Bengal score

  • Histological grading of the minor salivary glands with a focus score of greater than 1

  • Salivary flow of less than 1.5 mL in 15 minutes

  • Anti-Ro/SSA and/or anti-La/SSB antibodies

At this time, no conclusive evidence indicates that any single laboratory technique provides superior sensitivities or specificities.


Anti-Ro, along with other autoantibody levels, should be obtained when a rheumatologic/connective tissue disorder is suspected, specifically if the following conditions manifest or are suspected: [2, 3]

  • Photosensitivity or subacute cutaneous lupus

  • Primary Sjögren syndrome vasculitis

  • Cutaneous vasculitis/palpable purpura

  • Interstitial lung disease

  • Neonatal lupus

  • Congenital heart block

  • ANA-negative SLE

  • Nephritis, vasculitis, lymphadenopathy, leukopenia

  • Homozygous C2 and C4 deficiency with SLE-like disease

  • Rheumatoid factor positivity and severe systemic symptoms

  • SLE with interstitial pneumonitis