The prognostic value of routinely performed minor salivary gland assessments in primary Sjögren's syndrome

A review of salivary gland histopathology in primary Sjögren's syndrome with a focus on its potential as a clinical trials biomarker

Salivary gland changes, characterised by a focal lymphocytic sialadenitits, play an important role in the diagnosis of primary Sjögren's syndrome (PSS) and were first described over 40 years ago. Recent evidence suggests that minor salivary gland biopsy may also provide information useful for prognostication and stratification, yet difficulties may arise in the histopathological interpretation and scoring, and evidence exists that reporting is variable. With the increasing number of actual and proposed clinical trials in PSS, we review the evidence that might support the role of histopathology as a biomarker for stratification and response to therapy and highlight areas where further validation work is required.

Action of anti-M₃muscarinic acetylcholine receptor IgG of primary Sjögren's syndrome on the enzymatic antioxidant system in rat submandibular gland

BACKGROUND

We demonstrate that serum immunoglobulin G (IgG) directed against glandular M3 muscarinic acetylcholine receptors (M₃mAChR) and pilocarpine triggers the increment of superoxide dismutase (SOD) and catalase (CAT) and the production of nitric oxide (NO) and prostaglandin E₂(PGE₂).

METHODS

Enzyme-linked immunosorbent assay (ELISA) was performed in the presence of the human M₂mAChR synthetic peptide as antigen to detect in serum of pSS patients the autoantibodies. Further, SOD and CAT specific activity and NO were determined chemically in the presence of anti-M₃mAChR IgG and pilocarpine. The level of PGE₂generation in the presence of autoantibody and pilocarpine was determined by ELISA.

RESULTS

An association between anti-M₂mAChR autoantibodies and pilocarpine given the increment of the specific activity of SOD and CAT in the serum of pSS patients and in the rat submandibular gland was observed. As a result of this action, M₃synthetic peptide and atropine abrogated the stimulatory action. The L-type calcium channel, calcium/calmodulin complex and COX-2 inhibitors selectively blocked the increment of the specific activity of SOD and CAT in the rat submandibular gland. An increased production of NO and PGE₂by the cholinergic autoantibody and pilocarpine was also detected.

CONCLUSION

On the basis of these results, the increment of the specific activity of SOD and CAT in pSS patients as compared to control healthy individuals may be seen as a defensive reaction to the increment of the amount of ROS, which becoming uncontrollable, leads to irreversible cellular and tissue damage.

Clinical characteristics and biopsy accuracy in suspected cases of Sjögren's syndrome referred to labial salivary gland biopsy

BACKGROUND

Labial salivary gland biopsy (LSGB) is the most important diagnostic tool for the diagnosis of Sjögren's syndrome (SS), but its diagnostic value is rarely studied. This study assessed the sensibility and specificity of LSGB, and the clinical profiles of patients who were referred for biopsy.

METHODS

Retrospective analysis of the histopathological reports from LSGB and medical report data from patients who underwent LSGB between 2008 and 2011 was conducted.

RESULTS

About 290 biopsies were performed and 74 were excluded due to insufficient clinical data. Of the 216 patients, 0.46% was carrier of hepatitis C virus, 30.1% had primary SS (pSS), and 8.8% had secondary SS (sSS). Of the samples, 94.3% presented dryness symptoms, 51.6% experienced dryness only, 42.7% had systemic manifestations, and 66.9% presented low unstimulated salivary flow and/or Schirmer's test. LSGB was necessary in 67.6% to confirm the presence of SS based on the American-European Consensus Group 2002 criteria (AECG). Based on specialist's opinion, sensibility level was 86.57%, and specificity was 97.43%. Positive predictive value (PPV) was 95%, and negative predictive value (NPV) was 92.6%. Determined accuracy was 93.3%. Concordance (kappa coefficient) of LSGB and specialist's opinion was 0.851, and LSGB with AECG criteria was 0.806. Of the 98 patients referred with fibromyalgia and dryness, 36.7% had SS and LSBG focus score of ≥ 1. Patients with SS were older, and showed more severe lachrymal and salivary dysfunctions, greater frequency of fibromyalgia, anti-nuclear antibodies (ANA), anti-SSA-Ro, and anti-SSB-La.

CONCLUSIONS

Labial salivary gland biopsy has high sensibility, specificity, positive and negative predictive values for diagnosis of pSS. In the clinical practice, it is useful, especially for those patients with glandular dysfunctions and negative antibodies.

Sjögren Syndrome-associated lymphomas: an update on pathogenesis and management

Primary Sjögren Syndrome (pSS) is an autoimmune disease associated with an increased risk of lymphoma. Lymphomas complicating pSS are mostly low-grade B cell non-Hodgkin lymphomas, predominantly of marginal zone histological type. Mucosal localization is predominant, notably mucosa-associated lymphoid tissue lymphomas. Lymphomas often develop in organs where pSS is active, such as salivary glands. Germinal centre (GC)-like structures, high TNFSF13B (BAFF) and Flt3-ligand (FLT3LG) levels and genetic impairment of TNFAIP3 are new predictors of lymphoma development. These new findings allow a better understanding of the pathogenic mechanisms leading to lymphoma. We propose the following scenario: auto-immune B cells with rheumatoid factor (RF) activity are continuously stimulated by immune complexes containing antibodies against more specific auto-antigens, such as SSA/Ro, SSB/La or others. Germline abnormality of TNFAIP3 leads to a decreased control of the NF-kB pathway and thus promotes survival of B cells and oncogenic mutations especially in GC structure. Moreover, B cells are stimulated by a positive loop of activation induced by BAFF secretion. Thus, lymphomagenesis associated with pSS exemplifies the development of antigen-driven B-cell lymphoma. The control of disease activity by a well-targeted immunosuppressor is the primary objective of the management of the patient in order to repress chronic B cell stimulation.

A retrospective, multicenter study evaluating the prognostic value of minor salivary gland histology in a large cohort of patients with primary Sjögren’s syndrome

Objective

The objective of this report is to investigate the prognostic value of minor salivary glands (MSG) assessment, routinely performed with hematoxilin-eosin (H&E) staining, for the diagnosis of primary Sjögren’s syndrome (pSS).

Methods

We retrospectively evaluated clinical, serological and histological features of 794 pSS patients. H&E-stained sections were assessed using the Chisholm and Mason grading system and/or the focus score (FS).

Results

FS allowed the identification of a number of differences in the disease spectrum, and its prognostic role was further confirmed by quantifying the association between FS value and clinical/serological variables with binary logistic regression. Moreover, hypocomplementemia and FS resulted the only variables associated with lymphoma at univariate analysis, and FS appeared to be associated with lymphoma independently on complement fraction concentrations. Conversely, when patients were divided according to the Chisholm and Mason grading system, we failed to observe any significant difference between subgroups.

Conclusion

In addition to its diagnostic role, our data seem to support that the routine assessment of MSG-FS with H&E staining is useful to predict at the time of diagnosis the adverse outcomes, such as lymphoma and extraglandular manifestations, that complicate the pSS course. On this basis, it should be recommended that an MSG biopsy be performed even in those patients displaying clinical and serological criteria, allowing the diagnosis of pSS independent of histological status.