From the Guidelines
Typical lab findings in Sjögren's disease include positive anti-Ro/SSA and anti-La/SSB antibodies, which are present in 50-70% and 30-60% of patients respectively, as well as elevated rheumatoid factor, antinuclear antibodies (ANA), and hypergammaglobulinemia, reflecting the autoimmune nature of the disease 1. The diagnosis of Sjögren's syndrome is based on a combination of clinical and laboratory findings, including:
- Positive anti-Ro/SSA and anti-La/SSB antibodies
- Elevated rheumatoid factor
- Positive antinuclear antibodies (ANA)
- Hypergammaglobulinemia
- Decreased salivary flow rates
- Abnormal Schirmer's test results
- Cryoglobulins may be present in 10-15% of patients These laboratory abnormalities reflect the autoimmune nature of Sjögren's disease, characterized by lymphocytic infiltration of exocrine glands and production of autoantibodies, leading to the classic symptoms of dry eyes and dry mouth. The latest classification criteria for Sjögren's syndrome are based on the weighted sum of five items, including anti-SSA/Ro antibody positivity, focal lymphocytic sialadenitis, abnormal ocular staining score, Schirmer test result, and unstimulated salivary flow rate 1. In patients with suspected Sjögren's syndrome, a serological examination for anti-Sjögren syndrome A antibody (SSA or anti-Ro), anti-Sjögren syndrome B antibody (SSB or anti-La), rheumatoid factor, and antinuclear antibody should be ordered 1.
From the Research
Typical Lab Findings in Sjögren's Disease
- Anti-SSA/Ro and anti-SSB/La antibodies are commonly found in patients with Sjögren's syndrome, with a presence of 60-70% in primary Sjögren's syndrome (pSS) 2
- SSA/Ro (TRIM21) antibody staining is observed in the ductal areas of all pSS cases, while no staining is detected in healthy and non-specific chronic sialadenitis (NSCS) cases 3
- BAFF antibody staining is stronger in the ductal and inflammatory areas of pSS cases compared to the control group 3
- ENO1 antibody staining is higher and more intense in NSCS and pSS cases compared to those with normal salivary glands 3
- MMP-9 antibody staining is detected in the ductal areas of most NSCS and pSS cases, but also in 11% of healthy cases 3
- The presence of anti-Ro/SSA and anti-La/SSB antibodies is associated with an earlier disease onset, glandular dysfunction, and extraglandular manifestations in pSS 2
- The distribution of anti-Ro52-kD/SSA and anti-Ro60-kD/SSA autoantibodies differs between primary and secondary Sjögren's syndrome patients 4
- Anti-SSB/La antibodies are associated with extraglandular manifestations in primary SS and with a diffuse sclerodermic pattern in progressive systemic sclerosis (PSS) 5