From the Guidelines
Testing for Sjögren's syndrome should involve a combination of clinical evaluation, blood tests, and specialized procedures, including tests for autoantibodies, tear production assessment, and salivary gland function tests, as outlined in the latest classification criteria 1. To diagnose Sjögren's syndrome, the following steps should be taken:
- Clinical evaluation: A physical examination and review of symptoms, focusing on dryness in the eyes and mouth.
- Blood tests: Essential tests include autoantibodies such as anti-SSA (Ro) and anti-SSB (La), rheumatoid factor, antinuclear antibody (ANA), and inflammatory markers like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) 1.
- Eye tests: Assess tear production, including the Schirmer test, which measures tear volume using small strips of filter paper placed under the lower eyelids.
- Salivary gland function test: Measure saliva production to assess gland function.
- Lip biopsy: May be recommended to examine minor salivary gland tissue for inflammatory cells characteristic of Sjögren's.
- Imaging studies: Salivary gland ultrasonography or sialography may be used to assess gland function and structure. The diagnosis is typically made when multiple test results, combined with clinical symptoms, point to Sjögren's syndrome, using the latest classification criteria based on the weighted sum of five items: anti-SSA/Ro antibody positivity, focal lymphocytic sialadenitis, abnormal ocular staining score, Schirmer test result, and unstimulated salivary flow rate 1. Key considerations in testing for Sjögren's syndrome include:
- The condition's association with systemic immune dysfunction and potential for comorbid systemic conditions, emphasizing the need for comanagement with a rheumatologist 1.
- The importance of patient education on the nature of the problem, aggravating factors, and goals of treatment for successful management 1.
- The use of objective parameters to stage severity of dry eye syndrome and guide treatment options 1.
From the Research
Testing for Sjögren's Syndrome
To test for Sjögren's syndrome, several methods can be employed, including:
- Salivary gland biopsy: This involves taking a tissue sample from the salivary gland to check for the presence of autoantibody-producing cells 2
- Enzyme-linked immunosorbent assay (ELISA): This test measures the levels of anti-Ro/SSA and anti-La/SSB autoantibodies in the blood 2, 3
- Immunostaining: This technique uses biotinylated recombinant Ro and La proteins to detect autoantibody-producing cells in tissue samples 2
Autoantibody Tests
The presence of certain autoantibodies, such as anti-Ro/SSA and anti-La/SSB, can be indicative of Sjögren's syndrome. These autoantibodies can be detected in the blood using ELISA or other methods 3, 4, 5.
- Anti-Ro/SSA antibodies: These antibodies are found in approximately 50% of patients with primary Sjögren's syndrome 3
- Anti-La/SSB antibodies: These antibodies are found in approximately 16% of patients with primary Sjögren's syndrome and are often associated with a more severe disease course 3, 5
Clinical Evaluation
A comprehensive clinical evaluation is also essential for diagnosing Sjögren's syndrome. This includes assessing symptoms such as dry eyes and mouth, as well as evaluating for extra-glandular manifestations like vasculitis and lymphoproliferative disorders 3, 5, 6.
- Patients with anti-La/SSB antibodies tend to have a higher prevalence of hypergammaglobulinemia, rheumatoid factor, and lymphoproliferative disorders 5
- Patients without anti-SSA/SSB antibodies (double-negative) may have a delayed disease onset and a lower prevalence of parotid gland enlargement and extra-glandular involvement 6