Labial salivary gland biopsy is considered an essential diagnostic parameter for primary Sjogren's Syndrome (pSS), particularly when serology is inconclusive. However, its diagnostic benefits have received mixed reviews.
Objectives: Our objectives were to investigate the diagnostic correlations of labial salivary gland biopsy findings to pSS, and to evaluate the relationship between biopsy findings and clinical disease parameters.
Methods: Based on 2002 American-European Consensus Group Criteria, 42 pSS patients were selected and compared with 15 age-gender-ethnicity matched non-Sjogren sicca (nSS) patients and 24 healthy controls. Labial salivary gland biopsy specimens were evaluated by two oral pathologists (Kappa=0.95). Focus scores and other cellular, glandular and inflammatory characteristics were investigated. Clinical and laboratory parameters, including unstimulated whole saliva flow, tear flow (Schirmer's test), and titers of autoantibodies (anti-Ro/SSA and anti-La/SSB) were determined. Group differences were tested by Kruskal-Wallis test. Relationship between focus scores and clinical and laboratory variables were evaluated by Spearman's correlation coefficients.
Results: Mean (±SD) focus score in pSS group was 2.59 (±1.58), significantly higher than nSS or control group (
p<0.0001). Titers of anti-Ro/SSA and anti-La/SSB were significantly higher, whereas saliva and tear flow were significantly lower, in pSS than other two groups (
p<0.0001). Interestingly, focus scores in pSS correlated negatively with both saliva and tear flow (r=-.260,
p<0.05; r=-.270,
p<0.05, respectively). No correlations were observed between focus scores and autoantibody levels. No correlations were also observed between autoantibody levels and saliva or tear flow. Comparison of other histopathological characteristics (e.g. fibrosis, fatty replacement, germinal centers, Russell bodies, epimyoepithelial islands, etc.) supports glandular disfigurement and functional impairment in pSS.
Conclusions: Labial salivary gland biopsy provides valuable information in clinical situations and continues holding significant promise in refining diagnosis of pSS. However, inconsistencies in biopsy interpretation need further investigation.
Supported by NIH Grant #R01AR050782 and UMN School of Dentistry Summer Research Program.