Efficacy and safety of mizoribine for the treatment of Sjögren's syndrome: a multicenter open-label clinical trial

A randomized controlled trial to verify the irrigation of salivary glands in relieving xerostomia in patients with Sjögren's syndrome

OBJECTIVE

To verify the effect of triamcinolone acetonide (TA) and major salivary glands saline irrigation on relieving xerostomia in Sjögren's syndrome (SS) patients.

METHODS

The enrolled 49 SS patients were randomly assigned to the control group (no irrigation, n=16), saline group (irrigation with saline, n=17) and TA group (irrigation with TA, n=16). Fourteen cases of each group were treated differently but received the same examinations. The examinations include unstimulated whole saliva flow (UWS), chewing-stimulated whole saliva flow (SWS), citric acid-stimulated parotid flow (SPF), Clinical Oral Dryness Score (CODS), Xerostomia Inventory (XI) and EULAR SS Patient Reported Index (ESSPRI) of 1 week before irrigation (T0) and 1 week(T1), 8 weeks (T8), 16 weeks (T16) and 24 weeks (T24) after major salivary irrigation.

RESULTS

Each group had 14 cases with completed follow-ups. Both TA and saline irrigation of major salivary glands resulted in higher SWS and SPF of T8, T16 and than those at T0. ESSPRI (oral dryness domain) of T8, T16 and T24 were significantly lower than that at T0, respectively (P < 0.05). SWS and SPF of T8, T16 and T24 in the saline group were significantly higher than in the control group (P< 0.05). XI and ESSPRI (oral dress domain) of T8, T16 and T24 in the saline group were significantly lower than those in the control group, respectively (P< 0.05). SWS and SPF of T16 and T24 in the TA group were significantly higher than in the control group (P< 0.05). All cases with completed follow-up in TA and saline groups were divided into responders and non-responders. Compared with responders, the UWS, SWS, SPF and CODS of T0 in non-responders were significantly increased (P<0.05). Compared with responders, the XI and ESSPRI of T0 in non-responders were significantly decreased (P<0.05).

CONCLUSION

The irrigation of major salivary glands by TA and saline relieve xerostomia in SS patients. Patients with non-severe xerostomia (responders) have better relief after irrigation than patients with severe xerostomia (non-responders).

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier (ChiCTR210052314).

Management of Sjögren's Syndrome: Present Issues and Future Perspectives

In view of the new possibilities for the treatment of primary Sjögren's syndrome (pSS) given by the availability of new biotechnological agents targeting the various molecular and cellular actors of the pathological process of the disease, classification criteria aimed at selecting patients to be enrolled in therapeutic trials, and validated outcome measures to be used as response criteria to these new therapies, have been developed and validated in the last decades. Unfortunately, the therapeutic trials so far completed with these new treatments have yielded unsatisfactory or only partially positive results. The main issues that have been evoked to justify the poor results of the new therapeutic attempts are: (i) the extreme variability of the disease phenotypes of the patients enrolled in the trials, which are dependent on different underlying patterns of biological mechanisms, (ii) the fact that the disease has a long indolent course, and that most of the enrolled patients might already have irreversible clinical features. The advances in the research of new disease biomarkers that can better distinguish the different clinical phenotypes of patients and diagnose the disease in an earlier phase are also discussed.

Current State of Knowledge on Primary Sjögren's Syndrome, an Autoimmune Exocrinopathy

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune rheumatic disease characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands, whereby sicca syndrome and/or systemic manifestations are the clinical hallmarks, associated with a particular autoantibody profile. pSS is the most frequent connective tissue disease after rheumatoid arthritis, affecting 0.3-3% of the population. Women are more prone to develop pSS than men, with a sex ratio of 9:1. Considered in the past as innocent collateral passive victims of autoimmunity, the epithelial cells of the salivary glands are now known to play an active role in the pathogenesis of the disease. The aetiology of the "autoimmune epithelitis" still remains unknown, but certainly involves genetic, environmental and hormonal factors. Later during the disease evolution, the subsequent chronic activation of B cells can lead to the development of systemic manifestations or non-Hodgkin's lymphoma. The aim of the present comprehensive review is to provide the current state of knowledge on pSS. The review addresses the clinical manifestations and complications of the disease, the diagnostic workup, the pathogenic mechanisms and the therapeutic approaches.

Significance of Interleukin-6/STAT Pathway for the Gene Expression of REG Iα, a New Autoantigen in Sjögren's Syndrome Patients, in Salivary Duct Epithelial Cells

The regenerating gene, Reg, was originally isolated from a rat regenerating islet complementary DNA (cDNA) library, and its human homologue was named REG Iα. Recently, we reported that REG Iα messenger RNA (mRNA), as well as its product, was overexpressed in ductal epithelial cells in the salivary glands of Sjögren's syndrome patients. Furthermore, autoantibodies against REG Iα were found in the sera of Sjögren's syndrome patients, and the patients who were positive for the anti-REG Iα antibody showed significantly lower saliva secretion than antibody-negative patients. We found the mechanism of REG Iα induction in salivary ductal epithelial cells. Reporter plasmid containing REG Iα promoter (-1190/+26) upstream of a luciferase gene was introduced into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with several cytokines (interleukin (IL)-6, IL-8, etc.), upregulated in Sjögren's syndrome salivary ducts, and the transcriptional activity was measured. IL-6 stimulation significantly enhanced the REG Iα promoter activity in both cells. Deletion analysis revealed that the -141∼-117 region of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transducer and activator of transcription (STAT) binding. The introduction of small interfering RNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results indicated that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the REG Iα promoter in salivary ductal cells. This dependence of REG Iα induction upon IL-6/STAT in salivary duct epithelial cells may play an important role in the pathogenesis/progression of Sjögren's syndrome.

Maintenance treatment using the purine-synthesis inhibitor mizoribine in a patient with relapsing thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening disease. Although plasma exchange (PE) therapy and corticosteroids are standard remission induction and maintenance therapies, some patients are easily refractory and frequently relapse under treatment with this therapy, and require additional treatment. However, there are limited data about additional treatment interventions. We report a case of 56-year-old man who was hospitalized for fever, general fatigue and hemoglobinuria. Owing to the symptoms and the laboratory findings of hemolysis, he was diagnosed with TTP. He was treated with PE therapy and corticosteroids, and the TTP went into remission. However, his TTP relapsed and remission induction was attempted again. As a remission maintenance treatment, we used combination therapy with the purine-synthesis inhibitor mizoribine (MZR) and corticosteroids. The administration of MZR maintained disease activity with no adverse event for long periods and allowed us to gradually reduce the corticosteroids dose. Hence, we propose that MZR is an effective treatment for TTP maintenance.

Patient burden of Sjögren's: a comprehensive literature review revealing the range and heterogeneity of measures used in assessments of severity

CONTEXT

The severity of Sjögren's syndrome has been evaluated using a wide variety of clinical measures and patient-reported outcomes (PROs). This may contribute to the lack of clarity concerning the burden of Sjögren's from the patient perspective.

OBJECTIVE

To perform a comprehensive peer-reviewed literature analysis of the patient aspects of Sjögren's, focusing on PROs, to investigate the complexity underlying the evaluation of the syndrome and to elucidate the discordance between the different measures.

METHODS

We searched Embase for articles published between January 2005 and September 2015. Research articles, clinical and diagnostic reviews, and validation studies with a focus on patient aspects of Sjögren's were selected as the primary information source.

RESULTS

157 articles met the eligibility criteria. A wide variety of assessment measures used to evaluate glandular, extraglandular and functional domains were observed. Many different, non-validated Visual Analogue Scales, with a wide range of anchor words, were used in the quantification of Sjögren's disease burden, impeding comparisons between studies. Relatively few clinical trials of drug therapies used validated scales: European League Against Rheumatism Sjögren's Syndrome Patient Reported Index was used most often for symptom assessment and 36 Item Short Form Survey for quality of life (QoL).

CONCLUSION

A wide range and diversity of measures are used to evaluate the patient burden of Sjögren's; most are not validated for use in this disease. PRO endpoints, validated specifically in Sjögren's, that demonstrate improvement are needed. These measures should focus on QoL aspects important to patients and will most likely involve gauging change in function rather than patient-reported symptoms.

Interleukin-6/STAT pathway is responsible for the induction of gene expression of REG Iα, a new auto-antigen in Sjögren׳s syndrome patients, in salivary duct epithelial cells

The regenerating gene, Reg, was originally isolated from a rat regenerating islet cDNA library, and its human homolog was named REG Iα. Recently, we reported that REG Iα mRNA as well as its product were overexpressed in ductal epithelial cells in the minor salivary glands of Sjögren׳s syndrome (SS) patients. This study was undertaken to elucidate the role of cytokines and the subsequent intracellular mechanism for induction of REG Iα in the salivary glands of SS patients. We prepared a reporter plasmid containing REG Iα promoter (−1190/+26) upstream of a luciferase reporter gene. The promoter plasmid was introduced by lipofection into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with interleukin (IL)-6, IL-8, and a combination of the two. Thereafter transcriptional activity of REG Iα was measured by luciferase assay. We found that IL-6 stimulation, but not IL-8, significantly enhanced the REG Iα promoter activity in salivary ductal cells. Deletion analysis revealed that the region of −141 to −117 of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transduction and activation of transcription (STAT). The introduction of siRNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results showed that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the consensus sequence of REG Iα promoter in salivary ductal cells. This IL-6/STAT dependent REG Iα induction might play a role in the pathogenesis of SS.

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REG Iα was overexpressed in salivary ductal cells of patients with Sjögren׳s syndrome.

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IL-6 stimulation enhanced the REG Iα gene transcription in salivary ductal cells.

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STAT3 mediated IL-6-induced REG Iα transcription in salivary ductal cells.

Management of xerostomia and other complications of Sjögren's syndrome

This article provides an overview of the published literature in English in the past 63 years involving the management of xerostomia and other oral complications of Sjögren's syndrome. The evidence supporting studied interventions was evaluated using published criteria.

Topical and systemic medications for the treatment of primary Sjögren's syndrome

The treatment of primary Sjögren's syndrome (SS) is based principally on the management of sicca features and systemic manifestations. Sicca manifestations are treated symptomatically through administration of topical therapies, such as saliva substitutes and artificial tears; in patients with residual salivary gland function, stimulation of salivary flow with a sialogogue is the therapy of choice. The management of extraglandular features must be tailored to the specific organ or organs involved; however, limited data have been obtained from controlled trials in SS to guide the treatment of systemic symptoms using therapies including antimalarials, glucocorticoids, immunosuppressive drugs and biologic agents. Nevertheless, randomised controlled trials of biologic agents that target molecules and receptors involved in the aetiopathogenesis of primary SS have initiated a new era in the therapeutic management of the disease, although the potential risks and benefits of these agents must be carefully considered. In this Review, we analyse the evidence regarding the efficacy of the therapeutic agents currently available to treat the manifestations of SS. On the basis of this evidence, we provide guidance on the use of these agents in different clinical scenarios.

A case of Mikulicz's disease, IgG4-related plasmacytic syndrome, successfully treated by corticosteroid and mizoribine, followed by mizoribine alone

We report a case of Mikulicz's disease, IgG4-related plasmacytic syndrome, successfully treated with corticosteroid and mizoribine, followed by mizoribine alone. A 56-year-old woman experienced persistent bilateral swelling in the eyelids and submandibular region accompanied by lymphadenopathy without pain. The patient was diagnosed as having Mikulicz's disease since her bilateral lacrimal glands showed persistent swelling and biopsy specimens of the submandibular glands and lymph node showed diffuse infiltration of lymphocytes and plasma cells. Symptoms and laboratory data were improved with corticosteroids (30 mg). However, after tapering prednisolone to 5 mg, submandibular swelling developed. Adding mizoribine resulted in clinical improvement. Prednisolone was tapered and finally discontinued. Since the levels of IgG4 in peripheral blood were increased even after corticosteroid therapy and IgG4 was positive in a submandibular gland specimen obtained before the start of corticoid therapy. Thus, this case may be associated with IgG4. The present case is the first case in which mizoribine was effective for Mikulicz's disease and IgG4-related plasmacytic syndrome.

Usefulness of initial histological features for stratifying Sjogren's syndrome responders to mizoribine therapy

OBJECTIVES

To evaluate the response of patients with SS to mizoribine therapy in relation to histological features of minor salivary glands.

METHODS

Forty patients definitely diagnosed as having SS were treated with mizoribine (150 mg/day). Thirty-four untreated patients matched for age, baseline salivary secretion, etc., served as controls. Salivary secretion volume (measured by the Saxon test) and serum IgG level were measured before and after 24 weeks of treatment. Each histological finding (lymphocytic infiltration, acinar atrophy and intralobular fibrosis) was graded at baseline and the therapeutic responses were compared with the grade at 24 weeks in both the groups.

RESULTS

There was a significant increase of the salivary secretion volume after treatment with mizoribine as compared with the untreated control group. The effect of mizoribine on salivary secretion was more marked in patients having moderate lymphocytic infiltration and moderate or less severe acinar atrophy and intralobular fibrosis at baseline.

CONCLUSIONS

Mizoribine was clinically effective in patients with SS whose minor salivary glands had moderate cell infiltration and were free of intralobular fibrosis. The drug was less effective in patients who presented intralobular fibrosis. Histological evaluation of the minor salivary glands may serve to predict the response of SS patients to mizoribine therapy.