Histopathological comparison of Sjögren-related features between paired labial and parotid salivary gland biopsies of sicca patients.

OBJECTIVES: To compare focus score and other histopathological features between paired labial and parotid salivary gland biopsies in a diagnostic cohort of suspected Sjögren's disease (SjD) patients. METHODS: Labial and parotid salivary gland biopsies were simultaneously obtained from patients with sicca complaints, suspected of having SjD. Biopsies were formalin fixed and paraffin embedded. Sections were stained with haematoxylin & eosin, and for CD3, CD20, CD45, cytokeratin, CD21, Bcl6, activation-induced deaminase (AID) and IgA/IgG. Focus score and other histopathological features characteristic for SjD were analysed. RESULTS: Based on the expert opinion of three experienced rheumatologists, 36 patients were diagnosed as SjD and 63 as non-SjD sicca patients. When taking all patients together, absolute agreement of various histopathological features between labial and parotid biopsies was high and varied between 80% (focus score) and 93% [(pre-)lymphoepithelial lesions (LELs)]. More labial gland biopsies had a focus score ≥1 compared with their parotid counterpart. Accordingly, the area of infiltrate was larger in labial gland biopsies. When considering only SjD patients, labial glands contained significantly fewer B-lymphocytes and germinal centres/mm2, and less severe LELs compared with parotid glands. CONCLUSION: Labial and parotid glands from SjD patients contain similar histopathological key features, and thus both glands can be used for diagnosis and classification of SjD. However, parotid salivary glands reveal more evident B-lymphocyte-related features, while labial glands exhibit more inflammation, which may be partially unrelated to SjD.

Lymphoepithelial lesions in the salivary glands of primary Sjögren's syndrome patients: the perfect storm?

In patients with primary Sjögren's syndrome (pSS), inflamed salivary gland (SG) tissue may contain lymphoepithelial lesions (LELs). LELs are histopathological phenomena whereby B cells are present in hyperplastic ductal epithelium of the SG. Despite the potential role of LELs in pSS pathogenesis, studies on their formation, detection, and prevalence in benign lesions (not complicated with lymphoma) are scarce. Recent evidence however shows that LELs are present in approximately half of the patients with pSS, both in minor and major SGs. Migration of a small number of B cells into the epithelium appears to be a critical initial step in LEL formation. These intra-epithelial B cells are proliferative, exhibit an innate-like phenotype, and may be linked to MALT lymphoma development. Alongside intra-epithelial B cells, the hyperplastic epithelial partner in LELs also engages in the local immune reaction. Epithelial cells are a source of cytokines and chemokines, with CXCL10 in particular playing a potential role in LEL formation. Importantly, LELs also have a negative impact on the maintenance of SG homeostasis by SG progenitor cell (SGPC) populations, likely due to dysregulation of SGPC lineage commitment or induction of plasticity. In conclusion, LEL formation mirrors a perfect storm of B and epithelial cell interaction culminating in increased risk of B cell derailment and SGPC dysregulation in pSS patients. We therefore argue that attenuation of LEL formation is an important treatment goal to preserve SG function and prevent B cell derailment in pSS.

Increased Diagnostic Accuracy of the Labial Gland Biopsy in Primary Sjögren Syndrome When Multiple Histopathological Features Are Included.

OBJECTIVE: The aim of this study was to evaluate the diagnostic accuracy of the labial salivary gland biopsy based on multiple histopathological features in patients with suspected primary Sjögren syndrome (pSS). METHODS: Patients from a diagnostic sicca cohort with clinically suspected pSS who underwent a labial gland biopsy were included. Patients were categorized as having pSS or non-Sjögren syndrome sicca (non-SS sicca) based on vignettes scored by an expert panel. Labial gland biopsies were analyzed for the presence of four histopathological features: focus score (FS) ≥1, prelymphoepithelial and lymphoepithelial lesions, immunoglobulin G plasma cell shift, and germinal centers. Sensitivity and specificity of histologic features were calculated, and the optimal cutoff value for the number of histopathological features needed to diagnose pSS was determined with receiver operating curve analysis. RESULTS: A total of 38 patients were categorized as having pSS and 65 as having non-SS sicca. In labial gland biopsies of patients with pSS, the prevalence of FS ≥1 was 82%, followed by 68% for pre-lymphoepithelial and lymphoepithelial lesions, 63% for plasma cell shift, and 24% for germinal centers. Although FS ≥1 showed the highest sensitivity for patients with pSS (82%), specificity was higher for the other three features (98%-100%). The presence of two or more (of four) histopathological features had almost comparable sensitivity to FS alone, but specificity increased with 12% to 100%. For fulfillment of American College of Rheumatology/EULAR criteria, specificity increased from 84% to 95% when an abnormal biopsy was defined by the presence of two or more histopathological features instead of FS ≥1 only. CONCLUSION: The diagnostic accuracy of the labial gland biopsy increases when other histopathological features besides FS are taken into account, by reducing the number of false-positive biopsies.

More severe parotid gland histopathology in paediatric-onset than in adult-onset Sjögren's disease.

OBJECTIVES: The aim of this study was to assess the histopathological features of the parotid glands in patients with paediatric-onset Sjögren's disease (pedSjD) in comparison to patients with adult-onset Sjögren's disease (adSjD). METHODS: This study was performed in Groningen, the Netherlands. Patients with pedSjD from a diagnostic paediatric cohort (n=19), patients with adSjD from a diagnostic adult cohort (n=32) and patients with adSjD who participated in a clinical trial (n=42) with a baseline parotid gland biopsy were included. Parotid gland biopsies were analysed after (immuno)histological staining for SjD-related histopathological markers and compared between groups. RESULTS: All characteristic histopathological features of adSjD were also observed in pedSjD. There were no significant differences in lymphoepithelial lesions or immunoglobulin A (IgA)/IgG plasma cell shift between the pedSjD and the adSjD cohorts. However, compared with the diagnostic adSjD cohort (with comparable total EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) scores), pedSjD showed more severe lymphocytic infiltration as reflected by a higher focus score (p=0.003), a higher relative surface area of CD45+ infiltrate (p=0.041), higher numbers of B and T lymphocytes/mm2 (p=0.004 and p=0.029, respectively), a higher B/T lymphocyte ratio (p=0.013), higher numbers of CD21+ follicular dendritic cell networks/mm2 (p=0.029) and germinal centres (GC)/mm2 (p=0.002). Compared with the trial adSjD cohort, with significant higher total ESSDAI scores (p=0.001), only the B/T lymphocyte ratio and numbers of GC/mm2 were significantly higher in the pedSjD cohort (p=0.023 and p=0.018, respectively). CONCLUSION: Patients with pedSjD exhibit more pronounced histopathological features compared with patients with adSjD at diagnosis. Notably, the histopathology of patients with pedSjD aligns more closely with that observed in an adSjD clinical trial cohort, with even stronger B lymphocyte involvement.

Pretransplant NT-proBNP, Dialysis Vintage, and Posttransplant Mortality in Kidney Transplant Recipients.

BACKGROUND: End-stage kidney disease and dialysis vintage are characterized by accelerated atherosclerosis, volume overload, and progressive left ventricular hypertrophy, leading to elevated N-terminal probrain natriuretic peptide (NT-proBNP) levels. Pretransplant dialysis vintage is associated with excess mortality after transplantation. We want to study whether pretransplant NT-proBNP is associated with posttransplantation mortality and if it explains the association of dialysis vintage with posttransplantation mortality in kidney transplant recipients (KTR). METHODS: We measured plasma NT-proBNP on arrival at the hospital before kidney transplantation in 658 KTR between January 1995 and December 2005 in our center. Multivariable Cox regression analyses, adjusted for potential confounders, were used to prospectively study the associations of dialysis vintage and NT-proBNP with all-cause mortality. RESULTS: During median 12.7 (7.8-15.6) years of follow-up after transplantation, 248 (37.7%) KTR died. Dialysis vintage was associated with an increased risk of posttransplant mortality in the fully adjusted model (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.03-1.43; P = 0.02), independent of potential confounders. The association weakened materially and lost significance after further adjustment for NT-proBNP (HR, 1.14; 0.96-1.34; P = 0.14). NT-proBNP was independently associated with all-cause mortality in the fully adjusted model (HR, 1.34; 1.16-1.55; P < 0.001). The association remained independent of adjustment for dialysis vintage (HR, 1.31; 1.13-1.52; P < 0.001). CONCLUSIONS: Our study shows that longer dialysis vintage is associated with a higher mortality risk in KTR, and this association might be explained for a considerable part by variation in pretransplant NT-proBNP at the time of transplantation.