Assessing Real-World Utilization/Performance of Salivary Gland Biopsy in Diagnosis of Sjögren Disease: Impact of Overweighting Without Objective Glandular Testing.

OBJECTIVE

Retrospective cohort study assessing real-world use patterns and test properties of labial salivary gland biopsy (LSGBx) for diagnosing Sjögren's disease (SjD).

METHODS

We retrieved 89 LSGBx samples from our dermatopathology archive and obtained 23 cadaveric LSGBx samples without known autoimmune diseases for control. SjD cases included 15 seropositive Sjögren's disease (spSjD), 34 seronegative Sjögren's disease (snSjD), and 40 not SjD. All slides were de-identified and presented in random order to a blinded dermatopathologist and oral pathologist to review and score all samples according to established criteria. Patient demographics and clinical information were obtained via chart review. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of LSGBx were calculated, and odds of a SjD diagnosis after a positive LSGBx was assessed with logistic regression.

RESULTS

LSGBx supported SjD in 73.3% of spSjD, 73.5% of snSjD, and 55.0% of notSjD cases, and 21.7% of cadaveric specimens. Sensitivity for SjD (spSjD + snSjD) was 73.5%, specificity was 45.0%, PPV was 62.1%, and NPV was 58.1%. A positive LSGBx increased the odds of SjD (OR=2.27, 95% CI: 0.93-5.51). The odds were similar and non-significant for spSjD and snSjD. Cadaveric specimens had lower LSGBx positivity rates compared to notSjD cases (OR=0.24, 95% CI: 0.07-0.77). Objective measures of eye dryness (14/89 cases) or oral dryness (0/89) were infrequently assessed.

CONCLUSION

The predictive value of LSGBx for SjD is limited. The lack of objective clinical data in this cohort suggests that LSGBx is often heavily weighted for diagnosis, but these data question that approach.