investigations
Last reviewed 02/2021
- Schirmer test - for lack of lacrimal secretion i.e. keratoconjunctivis sicca
- salivary gland biopsy:
- Rose bengal and fluorescein staining - for lack of salivary secretion i.e. xerostomia
- Sjogren's syndrome is diagnosed if there is more than one focus where there are more than 50 lymphocytes per 4 mm2 in the salivary tissues
- blood tests:
- FBC - normochromic normocytic anaemia and leucopenia; in about 10% of patients
- raised ESR - in about 70% of patients
- hypergammaglobulinaemia - in about 80% of patients
- CRP - usually normal
- autoantibodies:
- anti-Ro and anti-La are found in 60% and 40% of cases respectively and are correlated with the presence of vasculitis; also found in SLE but with proportions of 25% and 10% respectively
- rheumatoid factor is present in 80% of cases and in 20% of patients there are cryoglobulins with rheumatoid factor activity