Biologic treatments in Sjögren's syndrome

Fingolimod reduces salivary infiltrates and increases salivary secretion in a murine Sjögren's model

Sjögren's Syndrome (SjS) is a chronic, systemic autoimmune disease causing xerostomia, xerophthalmia, and systemic symptoms. The principal pathological finding in SjS is the accumulation of lymphocytes in exocrine glandular tissue and elsewhere, leading to secretory dysfunction and other abnormalities. A rational therapeutic approach might be to interfere with lymphocyte migration to the periphery from central lymphoid tissues. We thus examined in an animal model of SjS the effects of Fingolimod (FTY720, Gilenya™), which interferes with migration of lymphocytes to peripheral sites. Fingolimod induces sequestration of lymphocytes in lymphoid organs by altering lymphocyte expression of sphingosine-1-phosphate receptors. In the C57Bl/6. NOD.Aec1Aec2 (AEC) model of SjS, Fingolimod reduced circulating T and B cell numbers. Treatment of AEC mice with Fingolimod increased salivary output and decreased the size of salivary gland infiltrates. Oral Fingolimod thus merits further consideration in the management of SjS in humans.

Intraductal injection as an effective drug delivery route in the management of salivary gland diseases

While conservative approaches for chronic sialoadenitis are in current use, the utility of intraductal injection therapy remains unclear. The purpose of this study is to provide evidence that substances delivered through intraductal injection of the salivary gland are able to be effectively distributed throughout the gland. Methylene blue dye (0.1 %) was injected intraductally into a porcine parotid gland (5 ml) of one group and the porcine submandibular gland (1 or 2 ml, n = 6 for each preparation) of another group. After the injection, the ductal systems were evaluated, sectioned, and observed microscopically. Color area analysis was performed on submandibular gland sections, and the infiltration ratio of the dye was calculated. The papillae of both Stensen's and Wharton's duct openings were easily identified with intraductally delivered methylene blue dye. The dye infiltration began from the central ductal region of the gland and could be easily observed to gradually disperse to the peripheral regions in each acinar. There were no statistically significant differences in infiltration ratios between anterior, midline, and posterior section of the submandibular gland. Also, there were no statistically significant differences in the ratios between 1 and 2 ml injections at all the three section positions. This study demonstrated that desired substances can be evenly delivered throughout the salivary gland through intraductal injections. The use of intraductal injections might serve as a potential therapeutic procedure in the management of salivary gland diseases.

Eligibility for clinical trials in primary Sjögren's syndrome: lessons from the UK Primary Sjögren's Syndrome Registry

OBJECTIVE

To identify numbers of participants in the UK Primary Sjögren's Syndrome Registry (UKPSSR) who would fulfil eligibility criteria for previous/current or potential clinical trials in primary SS (pSS) in order to optimize recruitment.

METHODS

We did a retrospective analysis of UKPSSR cohort data of 688 participants who had pSS with evaluable data.

RESULTS

In relation to previous/current trials, 75.2% fulfilled eligibility for the Belimumab in Subjects with Primary Sjögren's Syndrome study (Belimumab), 41.4% fulfilled eligibility for the Trial of Remicade in primary Sjögren's syndrome study (Infliximab), 35.4% for the Efficacy of Tocilizumab in Primary Sjögren's Syndrome study (Tocilizumab), 31.6% for the Tolerance and Efficacy of Rituximab in Sjögren's Disease study (Rituximab), 26.9% for the Trial of anti-B-cell therapy in pSS study (Rituximab) and 26.6% for the Efficacy and Safety of Abatacept in Patients With Primary Sjögren's Syndrome study (Abatacept). If recent measures of outcome, such as the EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score ⩾5 (measure of patient symptoms) and the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score ⩾5 (measure of systemic disease activity) are incorporated into a study design, with requirements for an unstimulated salivary flow >0 and anti-Ro positivity, then the pool of eligible participants is reduced to 14.3%.

CONCLUSION

The UKPSSR identified a number of options for trial design, including selection on ESSDAI ⩾5, ESSPRI ⩾5 and serological and other parameters.

Increase of Intracellular BAFF in B Cells of Sjögren's Patients Is Not Affected by Decrease of BAFFR

The presence of a broad spectrum of autoantibodies in Sjögren's syndrome (SjS) patients is the result of abnormal B-cell regulation that can be at least partially explained by abnormal BAFF/BAFFR regulation. The objective of this study was to determine both membrane and intracellular expression of BAFF/BAFFR in monocytes and B-cells in peripheral blood of 19 primary Sjögren's syndrome patients and 20 healthy controls using flow cytometry. We also measured sBAFF in serum. Compared to healthy controls, both surface and intracellular expression of BAFF was significantly increased in monocytes and B-cells of SjS patients. Also serum sBAFF level was elevated. Expression of BAFFR on B-cells of SjS patients was surprisingly decreased, but there was no clear increase or decrease within monocytes. Our results indicate that activated monocytes communicate with B-cells via BAFF and BAFFR, so that B-cells are stimulated, but BAFF is also produced to stimulate cells in autocrine way. The decrease of BAFFR expression in SjS patients suggests that there is the mechanism that attempts to take over in order to balance the high level of BAFF.

The value of animal models to study immunopathology of primary human Sjögren's syndrome symptoms

Sjögren's syndrome (SjS) is a complex chronic autoimmune disease of multifactorial etiology that results in eventual loss of secretory function in the exocrine glands. The challenges towards finding a therapeutic prevention or treatment for SjS are due primarily to a lack of understanding in the pathophysiological and clinical progression of the disease. In order to circumnavigate this problem, there is a need for appropriate animal models that resemble the major phenotypes of human SjS and deliver a clear underlying biological or molecular mechanism capable of defining various aspects for the disease. Here, we present an overview of SjS mouse models that are providing insight into the autoimmune process of SjS and advance our focus on potential diagnostic and therapeutic targets.

Primary Sjögren's syndrome related optic neuritis

AIM

To determine the clinical features, diagnosis and treatment of the primary Sjögren syndrome (SS) related optic neuritis.

METHODS

The clinical data of 8 patients (12 eyes) with primary SS related optic neuritis were analyzed retrospectively.

RESULTS

Eight of 128 consecutive patients with optic neuritis resulted from varied causes fulfilled the diagnostic criteria for the primary SS. They presented initially with the signs and symptoms of non-specific optic neuritis, and 5 patients presenting without dryness showed a chronic inflammation of submandibular gland or parotid gland, and lymphocyte infiltration was demonstrated by labial gland biopsy in 2 patients. There were serum positive titers for anti-Sjögren syndrome A (SSA) in 7 patients and anti-Sjögren syndrome B (SSB) in 8 patients. Anti-aquaporin-4 (AQP4) antibody was negative in all the 8 patients. Both glucocorticoids and immunosuppressive agent were administered, and visual acuity elevated in 8 eyes (66.7%), 3 patients (37.5%) recurred in the follow-up.

CONCLUSION

Primary SS related optic neuritis is less common and easily misdiagnosed. The conventional therapies for optic neuritis could not control the recurrence.

Possible Mechanisms of Lymphoma Development in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic as well as an organ-specific autoimmune disease characterized by lymphocytic infiltration of the glandular epithelial tissue. SS patients have been reported to be at highest risk of developing lymphoproliferative neoplasms, when compared with patients with other rheumatoid diseases. Factors such as cytokine stimulation, environmental factors, viral infection and genetic events as well as vitamin deficiency may contribute to the development of lymphoma. Over the past few decades, numerous efforts have been made to assess the relationship between lymphoma and SS. These include epidemiological surveys, molecular biologic assessments of clonality and well-linked register cohort studies evaluating the predictive value of clinical, laboratory and histological findings. Nevertheless, the mechanisms and factors predictive of lymphoma development in pSS patients remain to be defined. This review summarizes updated knowledge on the incidence of and risk factors for lymphoma development in pSS patients, as well as discussing the most recent findings on the development and treatment of lymphoma in pSS patients and the possible mechanism of lymphoma development.