Concept: Sjögren's syndrome
B cells contribute to multiple aspects of autoimmune disorders and may play a role in triggering disease. Thus, targeting B cells may be a promising strategy for treating autoimmune disorders. Better understanding of the B cell subsets that are responsible for the development of autoimmunity will be critical for developing efficient therapies. Here we have reported that B cells expressing the transcription factor T-bet promote the rapid appearance of autoantibodies and germinal centers in spontaneous murine models of systemic lupus erythematosus (SLE). Conditional deletion of T-bet from B cells impaired the formation of germinal centers and mitigated the development of kidney damage and rapid mortality in SLE mice. B cell-specific deletion of T-bet was also associated with lower activation of both B cells and T cells. Taken together, our results suggest that targeting T-bet-expressing B cells may be a potential target for therapy for autoimmune diseases.
Systemic Lupus Erythematosus is an autoimmune disease characterized by the formation of anti-nuclear autoantibodies, particularly anti-chromatin. Although the aetiology of the disease has not yet been fully elucidated, several mechanisms have been proposed to be involved. Due to an aberrant apoptosis or decreased removal of apoptotic cells, apoptotic blebs containing chromatin are released. During apoptosis, chromatin is modified that increases its immunogenicity. Myeloid dendritic cells (myDC) can take up apoptotic blebs and stimulate autoreactive T helper cells, and subsequently the formation of autoantibodies by autoreactive B cells. Immune complexes formed by anti-chromatin autoantibodies and modified chromatin deposit on basal membranes, and incite a local inflammation, but can also stimulate plasmacytoid dendritic cells to produce IFN-α. In addition to apoptotic blebs, neutrophil extracellular traps released by dying neutrophils, in a process called NETosis, may serve as a source of autoantigens as well. In this review, we describe the role of both apoptosis and NETosis in the pathogenesis of SLE, and show how both processes may interact with each other.
Salivary Gland Function Five Years after a Radioiodine Ablation in Patients with Differentiated Thyroid Cancer: Direct Comparison of Pre and Post-Ablation Scintigraphies and Their Relation to Xerostomia Symptoms.
- Thyroid : official journal of the American Thyroid Association
- Published about 5 years ago
Background Chronic sialadenitis is one of the most frequent chronic complications after radioiodine (RAI) therapy for thyroid cancer. To evaluate the long-term effects of RAI ablation on salivary gland function, we investigated scintigraphic changes in salivary glands by direct comparison of two salivary gland scintigraphies (SGS) taken before and at 5 yrs after a RAI ablation. Methods SGS was performed just before RIA (pre-SGS) and approximately 5 years after RAI ablation (F/U SGS) in 213 subjects who underwent thyroidectomy for thyroid cancer. The uptake score (US) was graded, and the ejection fraction (EF) was quantified for the parotid and submandibular glands at pre-SGS and F/U SGS. Changes in salivary gland function were graded as mild, moderate, or severe according to the differences in US and EF between the two SGS. Xerostomia were assessed and compared with the SGS findings. Results Worsening of the US was observed in 182 of 852 salivary glands (total: 21.3%; mild: 4.2%, moderate: 7.4%, severe: 9.7%), and 47.4% of the patients showed a worsening US for at least 1 of 4 salivary glands. A decrease in EF was observed in 173 of 852 salivary glands (total: 20.3%; mild: 5.4%, moderate: 6.8%, severe: 8.1%), and 43.7% of the patients experienced a decrease in the EF of at least 1 of the 4 salivary glands. Bilateral parotid gland dysfunction was the most commonly observed condition. Thirty-five (16.4%) patients complained of xerostomia at 5 years after RAI ablation. Scintigraphic changes in salivary gland function and xerostomia were more common in patients receiving 5.55 GBq, compared with 3.7 GBq. Xerostomia were more common in patients with submandibular gland dysfunction than those with parotid gland dysfunction (68.8% vs. 33.3%, P<0.05). The number of dysfunctional salivary glands was correlated with xerostomia (P<0.01). Conclusion About 20% of the salivary glands were dysfunctional on SGS at 5 years after a single RAI ablation, especially in patients who received higher doses of radioiodine. While parotid glands are more susceptible to I-131 related damage, xerostomia was more associated with submandibular gland dysfunction and the prevalence of dysfunctional salivary glands.
Abstract Aim: To compare collared silicone punctal plugs to intracanalicular SmartPlugs for the treatment of moderate to severe dry eye. Materials and methods: In this prospective, randomized, single blind, clinical study, 30 patients (60 eyes) who had been diagnosed with moderate to severe dry eye syndrome were enrolled. Study group I (n = 30 eyes) received collared silicone punctal plugs and group II (n = 30 eyes) received intracanalicular SmartPlugs. Data for the Schirmer I test, tear break-up time, vital staining, subjective symptoms and frequency of artificial tear application were recorded at baseline and 3 months after punctal occlusion. Results: There was no statistical significant difference for these values between group I and II. Conclusions: Although published data show free flow with irrigation and probing after SmartPlug insertion, the clinical effect in the treatment of dry eye appears to be the equally well to collared silicone punctal plugs. It seems likely that difference of design and localization between the treatment groups were of minor importance concerning impeding of natural and supplemental moisture.
Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease, defined by loss of B cell self-tolerance that results in production of antinuclear antibodies (ANA) and chronic inflammation. While the initiating events in lupus development are not well defined, overexpression of the RNA-recognizing toll-like receptor (TLR)7 has been linked to SLE in humans and mice. We postulated that autophagy plays an essential role in TLR7 activation of B cells for the induction of SLE by delivering RNA ligands to the endosomes, where this innate immune receptor resides. To test this hypothesis, we compared SLE development in Tlr7 transgenic (Tg) mice with or without B cell-specific ablation of autophagy (Cd19-Cre Atg5(f/f)). We observed that in the absence of B cell autophagy the 2 hallmarks of SLE, ANA and inflammation, were eliminated, thus curing these mice of lupus. This was also evident in the significantly extended survival of the autophagy-deficient mice compared to Tlr7.1 Tg mice. Furthermore, glomerulonephritis was ameliorated, and the serum levels of inflammatory cytokines in the knockout (KO) mice were indistinguishable from those of control mice. These data provide direct evidence that B cells require TLR7-dependent priming through an autophagy-dependent mechanism before autoimmunity is induced, thereafter involving many cell types. Surprisingly, hyper-IgM production persisted in Tlr7.1 Tg mice in the absence of autophagy, likely involving a different activation pathway than the production of autoantibodies. Furthermore, these mice still presented with anemia, but responded with a striking increase in extramedullary hematopoiesis (EMH), possibly due to the absence of pro-inflammatory cytokines.
The measurement of autoantibodies in the clinical care of autoimmune patients allows for diagnosis, monitoring, and even disease prediction. Despite their clinical utility, the functional significance of autoantibody target proteins in many autoimmune diseases remains unclear. Here we present a comprehensive review of 52 autoantigens commonly employed for the serological diagnosis of 24 autoimmune diseases. We discuss their function, whether they have extracellular-exposed epitopes, and whether antibodies to these proteins are known to be pathogenic. Transcriptomics (RNA-Seq) datasets were mined to display messenger RNA (mRNA) expression of the autoantigens across 32 tissues and organs. This analysis revealed that autoantigens cluster into one of three groups: expression in the tissue most strongly affected in the disease (Group I), ubiquitous expression with enrichment in immune tissues (Group II), or expression in other tissues not typically associated with the clinical presentation (Group III). Clustering demonstrated that the autoantigens within Group I were often proteins containing extracellular epitopes, many of which are targets of pathogenic autoantibodies. Group II autoantigens were targets for several rheumatological diseases, including Sjögren syndrome, systemic lupus erythematosus, myositis, and systemic sclerosis, and were ubiquitously expressed with enrichment in immune-rich tissues. This raises the possibility that immune cells in Group II disorders may be the source of autoimmunization and/or targets of immune cell responses. Since tissues showing enriched autoantigen gene expression may contribute to the development of autoantibodies and subsequent autoimmunity, the emergent patterns arising from the autoantigen transcriptomic profiles may provide a new heuristic framework to deconvolute these complex disorders.
Recurrent parotitis is a rare manifestation of Sjögren syndrome. The management of recurrent parotitis is challenging because conservative methods may be of limited efficacy and invasive approaches carry the risk of complications. Botulinum toxin has been shown to reduce salivary flow, and consequently, the results of its use in the management of recurrent parotitis have been encouraging. A 65-year-old female patient with recurrent parotitis due to Sjögren syndrome was referred to us, complaining of weekly bouts of inflammation. She required a course of antibiotics monthly to control bacterial superinfections. We treated her with onabotulinumtoxinA injections into both parotid glands at regular intervals. After her second injection cycle, she denied further inflammatory bouts, has not required antibiotics in more than 36 months, and denied any side effects. Botulinum toxin may be a safe and effective method of treating Sjögren syndrome-associated recurrent parotitis.
Immune checkpoint inhibitors (ICIs) targeting the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) pathways have demonstrated survival improvements in multiple advanced cancers, but also cause immune-related adverse events (IRAEs). IRAEs with clinical features similar to rheumatic diseases have not been well described. We report patients with inflammatory arthritis and sicca syndrome secondary to ICIs.
A 43-year-old woman with a 3-year history of sleep disturbances, dry mouth, and dry eyes presented with upper-eyelid swelling that had progressed during the past several months. Physical examination revealed nontender enlargement of the lacrimal and submandibular salivary glands.
BACKGROUND: A primary characteristic of complex genetic diseases is that affected individuals tend to cluster in families (that is, familial aggregation). Aggregation of the same autoimmune condition, also referred to as familial autoimmune disease, has been extensively evaluated. However, aggregation of diverse autoimmune diseases, also known as familial autoimmunity, has been overlooked. Therefore, a systematic review and meta-analysis were performed aimed at gathering evidence about this topic. METHODS: Familial autoimmunity was investigated in five major autoimmune diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid disease, multiple sclerosis and type 1 diabetes mellitus. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Articles were searched in Pubmed and Embase databases. RESULTS: Out of a total of 61 articles, 44 were selected for final analysis. Familial autoimmunity was found in all the autoimmune diseases investigated. Aggregation of autoimmune thyroid disease, followed by systemic lupus erythematosus and rheumatoid arthritis, was the most encountered. CONCLUSIONS: Familial autoimmunity is a frequently seen condition. Further study of familial autoimmunity will help to decipher the common mechanisms of autoimmunity.