The clinical value and histopathological correlation of lacrimal scintigraphy in patients with primary Sjögren’s syndrome

Advances in imaging of the lacrimal gland in Sjögren's syndrome: A narrative review

Due to lymphocytic infiltration of the salivary and lacrimal glands, Sjogren's syndrome (SS), a systemic autoimmune illness that mostly affects the exocrine glands, causes dry mouth (xerostomia) and dry eyes (xerophthalmia). Additionally, SS is associated with various comorbidities such as cardiovascular diseases, infections, musculoskeletal diseases, and cancers. Among patients with SS, xerophthalmia frequently arises as a complication, leading to insufficient tear production or rapid tear evaporation, thereby causing discomfort, irritation, and a gritty sensation in the eyes. This article aims to examine recent advancements in the imaging of the lacrimal gland in Sjögren's syndrome and briefly discusses the utilization of various imaging examinations for the lacrimal gland in this particular disease.

Epithelial Cell Adhesion Molecule in Primary Sjögren's Syndrome Patients: Characterization and Evaluation of a Potential Biomarker

Objective

To determine the subcellular localization of epithelial cell adhesion molecule (EpCAM) in labial salivary gland (LSG) and evaluate the diagnostic use of the extracellular domain of EpCAM (EpEX) and intracellular domain (EpICD) for primary Sjögren's syndrome (pSS).

Methods

Immunohistochemical (IHC) analysis was conducted using EpEX and EpICD domain-specific antibodies on labial salivary gland biopsy (LSGB) from participants. Chi-square or Fisher's exact analysis, Mann-Whitney U-test, and Kruskal-Wallis test compared differences among groups. Independent risk factors of pSS were determined by multiple logistic regression analysis. Receiver-operator characteristic curves (ROC) were carried out to estimate the diagnostic value.

Results

Compared to non-SS controls, loss of membranous EpEX and EpICD expression was observed in LSGB of pSS patients, which occurred in parallel with increased accumulation of cytoplastic and nuclear EpICD. The subcellular EpEX/EpICD expressions were associated with various features of pSS patients, especially histopathological grade of LSGB. Furthermore, high IHC scores of membranous EpEX were independent risk factors for pSS, even for the pSS patients at early stage. The IHC scores of subcellular EpEX/EpICD were of great diagnostic value for pSS with high sensitivity (70-80%) and specificity (85-95%).

Conclusion

This study first found the aberrant expression pattern of EpCAM in LSG of pSS patients. The IHC scores of subcellular EpEX/EpICD were demonstrated to have the potential to act as diagnostic biomarkers for pSS.

Evaluation of the tear clearance rate by dacryoscintigraphy in patients with obstructive meibomian gland dysfunction

PURPOSE

To measure tear clearance values in patients with meibomian gland dysfunction (MGD) with a dynamic nuclear medicine method, namely, dacryoscintigraphy (DSCI).

METHODS

Twenty-four MGD patients and 24 healthy volunteers were examined. During DSCI one drop of a solution with 100 MBq/mL^99mTc sodium pertechnetate was instilled with a micropipette into the lacrimal lake of both eyes. Measurements were performed according to a dynamic data acquisition protocol, which resulted in summed DSCI images. Data were also evaluated separately in special regions of interest (ROI), and consecutive time activity curves were created. Tear clearance (T½) values were calculated based on the activity curves. In addition, tear osmolarity measurements, tear breakup time (tBUT), and Schirmer I (ST_I) tests were performed prior to DSCI examination.

RESULTS

The T½ values were 29.91 ± 11.61 min in MGD patients and 6.26 ± 1.5 min in healthy controls. Tear osmolarity parameters were 308 ± 9.41 mOsm/L and 288.9 ± 6.4 mOsm/L, tBUT values were 5.54 ± 2.73 s and 11.4 ± 2.7 s, while the ST_I test values were 6.17 ± 2.78 mm and 13.58 ± 3.8 mm, respectively. The differences were significant (p < 0.01) in all cases.

CONCLUSIONS

Although the MGD patients' lacrimal drainage systems were patent their tear clearance values were significantly higher than those of healthy volunteers, which may be caused by decreased drainage of tears from the eyes towards the nasal cavity. The understanding of new features regarding the altered physico-chemical characteristics of MGD tears has been augmented by the results of this study.