Present and future of biologic drugs in primary Sjögren's syndrome

Pulmonary Manifestations of Sjögren's Disease

Sjögren's disease (SjD) is a chronic, progressive autoimmune condition of exocrine and extraglandular tissues. It can present with isolated disease characterized by lymphocytic infiltration of salivary or lacrimal glands, but in approximately one-third of the patients, lymphocytic infiltration extends beyond exocrine glands to involve extraglandular organs such as the lungs. Pulmonary complications have been reported to occur between 9 and 27% of patients with SjD across studies. Respiratory manifestations occur on a spectrum of severity and include airways disease, interstitial lung disease, cystic lung disease, and lymphoma. Lung involvement can greatly affect patients' quality of life, has a major impact on the overall prognosis, and frequently leads to alteration in the treatment plans, highlighting the importance of maintaining a high index of clinical suspicion and taking appropriate steps to facilitate early recognition and intervention.

Identification of key genes in salivary gland in Sjögren's syndrome complicated with Hashimoto thyroiditis: Common pathogenesis and potential diagnostic markers

The coexistence of Sjögren's syndrome (SS) and Hashimoto thyroiditis (HT) has been confirmed, but the common mechanism of its co-occurrence remains unknown. This study aims to further explore the underlying mechanism and biomarkers for the co-occurrence of SS and HT. The Gene Expression Omnibus databases were used to obtain gene expression profiles for SS (GSE127952 and GSE23117) and HT (GSE29315 and GSE138198). Following identifying SS and HT's shared differentially expressed genes, functional annotation, protein-protein interaction network creation, and module assembly were performed to discover hub genes. H&E staining and immunohistochemistry were performed to validate the expression of the hub genes in salivary glands. Finally, the receiver operating characteristic (ROC) curve was utilized to assess the discrimination of the hub genes as biomarkers in predicting SS, this study applied CIBERSORTx to analyze the immune infiltration in SS and HT in addition. A total of 48 common differentially expressed genes (48 upregulated genes and 0 downregulated genes) were chosen for further investigation. We analyzed the expression and function of PTPRC, CD69, IKZF1, and lymphocyte cytosolic protein 2 via H&E, immunohistochemistry, and ROC analysis. The 4 hub genes were mainly enriched in the T-cell receptor signaling pathway. We then evaluated and verified the diagnosis value of 4 hub genes in clinical minor labial gland biopsy of SS with HT, SS without HT, and non-SS. ROC analysis revealed that the 4 hub genes had a strong diagnostic value. Our study showed the common pathogenesis of SS and HT. These hub genes and diagnostic models may put forward some new insights for diagnosing and treating SS complicated with HT.

Targets of total glucosides of paeony in the treatment of Sjogren syndrome: A network pharmacology study

BACKGROUND

We aimed to explore the underlying mechanism of the total glucoside of peony (TGP) in treating Sjogren syndrome (SS) using the network pharmacology approach.

METHODS

The protein targets of TGP and SS were identified by database search. Then, the intersection of the two groups was studied. The drug-target network between TGP and the overlapping genes was constructed, visualized, and analyzed by Cytoscape software. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment were performed to analyze these genes. Finally, the predictions of potential targets were evaluated by docking study.

RESULTS

Forty-six overlapping genes were discovered. The results suggested that TGP used in the treatment of SS is associated with cellular tumor antigen p53, neurotrophic tyrosine kinase receptor type 1, and epidermal growth factor receptor, as well as their related 3372 protein networks, which regulate intrinsic apoptotic signaling pathway, cellular response to oxidative stress, rhythmic process, and other processes. Molecular docking analysis proved that hydrogen bonding is the main form of interaction.

CONCLUSION

Our research provided the protein targets affected by TGP in SS treatment. The key targets (caspase 3, vascular endothelial growth factor A, glyceraldehyde-3-phosphate dehydrogenase, etc.), which involve 3372 proteins, are the multitarget mechanism of TGP in SS treatment.

A review on applications of abatacept in systemic rheumatic diseases

Abatacept is a CTLA-4Ig fusion protein that selectively modulates the CD80/CD86:CD28 costimulatory pathway required for full T-cell activation. The FDA has approved it to be used to treat adult rheumatoid arthritis, juvenile idiopathic arthritis, and adult active psoriatic arthritis. Considering the vital pathogenic role of the CTLA-4 pathway in autoimmune diseases, abatacept could efficiently treat other systemic rheumatic diseases. Here we reviewed the published literature to profile the perspectives about the off-label uses of abatacept, especially in those refractory cases with inadequate responses to conventional therapies and biologic agents. Abatacept can be a promising therapeutic option and contribute to reducing hormone dependence and correlated adverse events.

Patients with Interstitial Lung Disease Secondary to Autoimmune Diseases: How to Recognize Them?

The diagnostic assessment of patients with Interstitial Lung Disease (ILD) can be challenging due to the large number of possible causes. Moreover, the diagnostic approach can be limited by the severity of the disease, which may not allow invasive exams. To overcome this issue, the referral centers for ILD organized Multidisciplinary Teams (MDTs), including physicians and experts in complementary discipline, to discuss the management of doubtful cases of ILD. MDT is currently considered the gold standard for ILD diagnosis, but it is not often simple to organize and, furthermore, rheumatologists are still not always included. In fact, even if rheumatologic conditions represent a common cause of ILD, they are sometimes difficult to recognize, considering the variegated clinical features and their association with all possible radiographic patterns of ILD. The first objective of this review is to describe the clinical, laboratory, and instrumental tests that can drive a diagnosis toward a possible rheumatic disease. The secondary objective is to propose a set of first-line tests to perform in all patients in order to recognize any possible rheumatic conditions underlying ILD.

Sjögren Syndrome With Associated Lymphocytic Interstitial Pneumonia Successfully Treated With Tacrolimus and Abatacept as an Alternative to Rituximab

Interstitial lung disease (ILD) is a significant complication of Sjögren syndrome (SS) associated with increased morbidity and mortality. The mainstay of treatment remains corticosteroid administration, with or without additional immunosuppressive therapies. Preliminary studies in SS have shown benefit in glandular and serologic parameters following treatment with the CTLA4 immunoglobulin fusion protein abatacept. Topical tacrolimus has been effective for ocular symptoms in SS, but systemic therapy has not been reported. We describe the first case, to our knowledge, of the successful use of a combination of systemic tacrolimus and abatacept in severe refractory SS and related ILD.

Development of tibulizumab, a tetravalent bispecific antibody targeting BAFF and IL-17A for the treatment of autoimmune disease

We describe a bispecific dual-antagonist antibody against human B cell activating factor (BAFF) and interleukin 17A (IL-17). An anti-IL-17 single-chain variable fragment (scFv) derived from ixekizumab (Taltz®) was fused via a glycine-rich linker to anti-BAFF tabalumab. The IgG-scFv bound both BAFF and IL-17 simultaneously with identical stoichiometry as the parental mAbs. Stability studies of the initial IgG-scFv revealed chemical degradation and aggregation not observed in either parental antibody. The anti-IL-17 scFv showed a high melting temperature (Tm) by differential scanning calorimetry (73.1°C), but also concentration-dependent, initially reversible, protein self-association. To engineer scFv stability, three parallel approaches were taken: labile complementary-determining region (CDR) residues were replaced by stable, affinity-neutral amino acids, CDR charge distribution was balanced, and a H44-L100 interface disulfide bond was introduced. The Tm of the disulfide-stabilized scFv was largely unperturbed, yet it remained monodispersed at high protein concentration. Fluorescent dye binding titrations indicated reduced solvent exposure of hydrophobic residues and decreased proteolytic susceptibility was observed, both indicative of enhanced conformational stability. Superimposition of the H44-L100 scFv (PDB id: 6NOU) and ixekizumab antigen-binding fragment (PDB id: 6NOV) crystal structures revealed nearly identical orientation of the frameworks and CDR loops. The stabilized bispecific molecule LY3090106 (tibulizumab) potently antagonized both BAFF and IL-17 in cell-based and in vivo mouse models. In cynomolgus monkey, it suppressed B cell development and survival and remained functionally intact in circulation, with a prolonged half-life. In summary, we engineered a potent bispecific antibody targeting two key cytokines involved in human autoimmunity amenable to clinical development.

World Workshop on Oral Medicine VII: Immunobiologics for salivary gland disease in Sjögren's syndrome: A systematic review

OBJECTIVE

This systematic review evaluated the efficacy of immunobiologics for the management of oral disease in Sjögren's syndrome (SS).

MATERIALS AND METHODS

MEDLINE^® , Embase, Scopus, and the Cochrane Library were searched for evidence on the use of immunobiologics for management of glandular disease in SS. Primary outcomes were xerostomia and salivary gland dysfunction, assessed via visual analogue scales, disease-specific scales for SS, measurement of salivary flow, ultrasound data, and quality of life measures.

RESULTS

Seventeen studies (11 randomized controlled trials and 6 observational studies) met inclusion criteria. Rituximab showed efficacy in improving salivary gland function but not xerostomia. Abatacept showed promise in improving both xerostomia and salivary flow. Belimumab exhibited long-term improvement of salivary flow and subjective measures. The novel agent CFZ533 improved both disease activity and patient-reported indexes.

CONCLUSIONS

There is strong evidence pointing to the efficacy of rituximab in the management of oral disease in SS. Future controlled trials may elucidate the efficacy of belimumab and abatacept. The new drug CFZ533 is a promising alternative for the management of SS and its salivary gland involvement. In considering these agents, the promise of efficacy must be balanced against the harmful effects associated with biologic agents.

Contribution of pulmonary function tests (PFTs) to the diagnosis and follow up of connective tissue diseases

Introduction

Connective Tissue Diseases (CTDs) are systemic autoimmune conditions characterized by frequent lung involvement. This usually takes the form of Interstitial Lung Disease (ILD), but Obstructive Lung Disease (OLD) and Pulmonary Artery Hypertension (PAH) can also occur. Lung involvement is often severe, representing the first cause of death in CTD. The aim of this study is to highlight the role of Pulmonary Function Tests (PFTs) in the diagnosis and follow up of CTD patients.

Main body

Rheumatoid Arthritis (RA) showed mainly an ILD with a Usual Interstitial Pneumonia (UIP) pattern in High-Resolution Chest Tomography (HRCT). PFTs are able to highlight a RA-ILD before its clinical onset and to drive follow up of patients with Forced Vital Capacity (FVC) and Carbon Monoxide Diffusing Capacity (DL_CO). In the course of Scleroderma Spectrum Disorders (SSDs) and Idiopathic Inflammatory Myopathies (IIMs), DL_CO appears to be more sensitive than FVC in highlighting an ILD, but it can be compromised by the presence of PAH. A restrictive respiratory pattern can be present in IIMs and Systemic Lupus Erythematosus due to the inflammatory involvement of respiratory muscles, the presence of fatigue or diaphragm distress.

Conclusions

The lung should be carefully studied during CTDs. PFTs can represent an important prognostic tool for diagnosis and follow up of RA-ILD, but, on their own, lack sufficient specificity or sensitivity to describe lung involvement in SSDs and IIMs. Several composite indexes potentially able to describe the evolution of lung damage and response to treatment in SSDs are under investigation. Considering the potential severity of these conditions, an HRCT jointly with PFTs should be performed in all new diagnoses of SSDs and IIMs. Moreover, follow up PFTs should be interpreted in the light of the risk factor for respiratory disease related to each disease.

Managing fatigue in patients with primary Sjögren's syndrome: challenges and solutions

Primary Sjögren's syndrome (pSS) patients identify fatigue as their most important symptom and the one most difficult to cope with, but there are still many challenges and few solutions to manage this debilitating symptom. Promising pharmacological treatments, such as rituximab, have failed in more stringent tests including randomized controlled trials (RCTs) and meta-analysis. While non-pharmacological interventions may be safer, less costly, and address other common comorbidities, to date only aerobic exercise seems to be effective at reducing fatigue in pSS. All interventions, pharmacological or not, need to be tested in high-quality RCTs. The aim of this review is to provide an overview of fatigue management in pSS and discuss potential opportunities for future research.

A retrospective analysis of distinguishing features of chest HRCT and clinical manifestation in primary Sjögren's syndrome-related interstitial lung disease in a Chinese population

To characterize the distinctive chest high-resolution computerized tomography (HRCT) features and clinical manifestations of primary Sjögren syndrome (pSS)-related interstitial lung disease (ILD). The demographic data, clinical manifestations, and laboratory and radiological findings of 527 pSS patients were retrospectively analyzed. ILD was defined based on the presences of pulmonary signs in HRCT. Two hundred six of 527 patients were diagnosed as pSS-ILD, and the prevalence was 39.1%. The three most frequent abnormalities in HRCT were reticular pattern (92.7%), ground-glass attenuation (87.4%), and bronchovascular bundle thickening (82%). One hundred twenty-four cases (60.2%) of the pSS-ILD patients had only a single HRCT pattern, which involved 86 non-specific interstitial pneumonitis (NSIP) cases (41.7%), 22 usual interstitial pneumonia (UIP) cases (10.68%), 8 organizing pneumonia (OP) cases (3.9%), and 8 lymphocytic interstitial pneumonia (LIP) cases (3.9%), respectively. Besides, the more important observation was that 82 cases had no less than two HRCT patterns, and NSIP admixed with OP (43.9%), NSIP admixed with UIP (35.4%), and NSIP admixed with LIP (19.5%) were the most frequent. HRCT of pSS-ILD patients demonstrated bilateral infiltrates (99%), with abnormalities predominantly in the lower lobes (89.3%) and subpleural areas (81.1%), and a few lesions were characterized by hilum distributed (8.7%). Pulmonary function tests (PFTs) revealed impaired diffusion capacity for carbon monoxide and total lung capacity, and the rate of small airway lesions in the pSS-ILD patients was 3.5 times higher in patients of pSS. Logistic regression analysis showed that dry cough (OR 59.05), clubbing (OR 6.26), elevated lactate dehydrogenase (OR 21.38) and positive anti-Ro (OR 7.86) were relevant factors of pSS-ILD. ILD is the common pulmonary involvement of pSS and the prevalence of pSS-ILD is 39.1%. The single pattern of NSIP and UIP in HRCT are the commonest, and about 40% of the pSS-ILD patients possess multiple patterns in HRCT. The classification of idiopathic pulmonary fibrosis cannot completely include the pulmonary imaging features of pSS-ILD.