Reevaluation of laboratory parameters in relation to histological findings in primary and secondary Sjögren's syndrome.
We reevaluated the diagnostic value of laboratory parameters in relation to histopathological findings in Sjögren's syndrome (SS) to clarify whether autoantibodies are useful diagnostic criteria for SS, and whether any laboratory data are useful in estimating the degree of salivary gland change. Laboratory parameters and histopathological findings were analyzed in 96 patients examined by labial biopsy. The percentage of cases with positive assays of rheumatoid factor and anti-SS-A/Ro antibodies was significantly higher in Definite SS. Patients with dense mononuclear cell infiltration of salivary tissues also had higher titers of rheumatoid factor. No useful laboratory parameters were found for the diagnosis of secondary SS. Rheumatoid factor and anti-SS-A/Ro antibodies are useful for the diagnosis of primary SS, and rheumatoid factor is also an indicator of the severity of salivary glandular damage.