Xist ribonucleoproteins promote female sex-biased autoimmunity.

Autoimmune diseases disproportionately affect females more than males. The XX sex chromosome complement is strongly associated with susceptibility to autoimmunity. Xist long non-coding RNA (lncRNA) is expressed only in females to randomly inactivate one of the two X chromosomes to achieve gene dosage compensation. Here, we show that the Xist ribonucleoprotein (RNP) complex comprising numerous autoantigenic components is an important driver of sex-biased autoimmunity. Inducible transgenic expression of a non-silencing form of Xist in male mice introduced Xist RNP complexes and sufficed to produce autoantibodies. Male SJL/J mice expressing transgenic Xist developed more severe multi-organ pathology in a pristane-induced lupus model than wild-type males. Xist expression in males reprogrammed T and B cell populations and chromatin states to more resemble wild-type females. Human patients with autoimmune diseases displayed significant autoantibodies to multiple components of XIST RNP. Thus, a sex-specific lncRNA scaffolds ubiquitous RNP components to drive sex-biased immunity.

Myositis and Its Mimics: Guideline Updates, MRI Characteristics, and New Horizons.

Myositis is defined as inflammation within skeletal muscle and is a subcategory of myopathy, which is more broadly defined as any disorder affecting skeletal muscle. Myositis may be encountered as a component of autoimmune and connective tissue disease, where it is described as idiopathic inflammatory myopathy. Myositis can also be caused by infections, as well as toxins and drugs, including newer classes of medications. MRI plays an important role in the diagnosis and evaluation of patients with suspected myositis, but many entities may have imaging features similar to myositis and can be considered myositis mimics. These include muscular dystrophies, denervation, deep venous thrombosis, diabetic myonecrosis, muscle injury, heterotopic ossification, and even neoplasms. In patients with suspected myositis, definitive diagnosis may require integrated analysis of imaging findings with clinical, laboratory, and pathology data. The objectives of this article are to review the fundamental features of myositis, including recent updates in terminology and consensus guidelines for idiopathic inflammatory myopathies, the most important MRI differential diagnostic considerations for myositis (i.e., myositis mimics), and new horizons, including the potential importance of artificial intelligence and multimodal integrated diagnostics in the evaluation of patients with muscle disorders.

Peripheral blood leucocyte telomere length is associated with progression of interstitial lung disease in systemic sclerosis.

BACKGROUND: Peripheral blood leucocyte telomere length (PBL-TL) is associated with outcomes in patients with idiopathic pulmonary fibrosis. Whether PBL-TL is associated with progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is unknown. METHODS: A retrospective observational cohort study was performed using prospectively collected data from 213 patients with SSc followed at the University of California San Francisco (UCSF) Scleroderma Center. PBL-TL was measured by quantitative PCR of DNA isolated from peripheral blood. Associations between PBL-TL and pulmonary function test trends in patients with SSc-ILD were assessed by longitudinal analysis using Generalised Linear Mixed Models. Findings were validated in a cohort of 61 patients with SSc-ILD enrolled in the Stanford University Scleroderma Center database. RESULTS: Patients with UCSF SSc with ILD were found to have shorter PBL-TL compared with those without ILD (6554±671 base pairs (bp) vs 6782±698 bp, p=0.01). Shorter PBL-TL was associated with the presence of ILD (adjusted OR 2.1 per 1000 bp TL decrease, 95% CI [1.25 to 3.70], p=0.006). PBL-TL was shorter in patients with SSc-ILD lacking SSc-specific autoantibodies compared with seropositive subjects (6237±647 bp vs 6651±653 bp, p=0.004). Shorter PBL-TL was associated with increased risk for lung function deterioration with an average of 67 mL greater loss in per year for every 1000 bp decrease in PBL-TL in the combined SSc-ILD cohorts (longitudinal analysis, adjusted model: 95% CI -104 mL to -33 mL, p<0.001). CONCLUSIONS: These findings suggest that telomere dysfunction may be associated with SSc-ILD progression and that PBL-TL measurement may be useful for stratifying risk for SSc-ILD progression.

Distinct dermatomyositis populations are detected with different autoantibody assay platforms.

OBJECTIVES: To compare autoantibody-defined dermatomyositis sub-populations using immunoprecipitation-based assays, a commercially available line immunoblot assay and alternate commercial ELISA assays. METHODS: Banked plasma from 261 carefully phenotyped dermatomyositis patients was studied. Immunoprecipitation-based assays were used to detect antibodies against Mi2, TIF1-γ MDA5, NXP2, SAE1 and PM-Scl, while anti-Jo1 antibodies were assayed using ELISA. These data were compared with that obtained using a commercial line immunoblot, and, additionally, for Mi2, TIF1-γ, MDA5, commercially available ELISA kits. Test agreement was measured using Cohen's kappa statistic, and phenotypic differences between differentially identified groups are described. RESULTS: Line immunoblot, immunoprecipitation, and ELISA detected increasingly larger nested pools of anti-TIF1-γ samples, with increasing frequency of concurrent anti-Mi2 reactivity and decreasing incidence of malignancy. Line immunoblot and immunoprecipitation showed fair concordance for identifying anti-NXP2 antibodies (Cohen's kappa=0.71) but very good agreement for identifying antibodies against Mi2, MDA5, and SAE1 (Cohen's κ=0.9, 0.94, 0.88, respectively). Anti-PM-Scl results showed moderate agreement (Cohen's κ=0.48) between immunoblot and immunoprecipitation. CONCLUSIONS: Our results demonstrate that for some specificities, especially anti-TIF1-γ, antibody results obtained using different assay platforms vary, and identify significantly different patient populations. These findings highlight the need for standard adoption of carefully validated platforms to detect dermatomyositis autoantibodies.

Clinical factors associated with cutaneous histopathologic findings in dermatomyositis.

BACKGROUND: Common histopathologic findings in cutaneous dermatomyositis include vacuolar interface with dyskeratosis, mucin, and perivascular inflammation. Data examining the relationships between these and other histologic abnormalities, or their dependence on biopsy site, and medications are limited. METHODS: Using 228 dermatomyositis skin biopsies and statistical analyses including Chi-squared analyses, calculations of relative risk, and adjusted generalized estimating equation regressions, we investigated relationships between 14 histopathologic findings and the impact of clinical factors on these findings. RESULTS: In biopsies taken from sites of visible rash, interface dermatitis was seen in 91%, and 95% had at least one of perivascular inflammation, mucin, or basal vacuolization. Vascular abnormalities were not closely associated with epidermal or inflammatory findings. Concomitant prednisone significantly decreased the odds of basal vacuolization (odds ratio [OR] = 0.34, 95% confidence interval [CI]: 0.12-0.98, P-value = 0.05), perivascular inflammation (OR = 0.19, 95% CI: 0.07-0.53, P-value = 0.002), and vessel damage (OR = 0.81, 95% CI: 0.68-0.96, P-value = 0.02). CONCLUSION: Vasculopathy and classic findings of interface dermatitis may be driven by unique pathways in dermatomyositis. Corticosteroid use may impact skin biopsy findings. There is a need for clinicopathologic correlation when diagnosing dermatomyositis.

Dermatomyositis Clinical and Pathological Phenotypes Associated with Myositis-Specific Autoantibodies.

PURPOSE OF REVIEW: Dermatomyositis is an idiopathic inflammatory myopathy with a variety of systemic and cutaneous manifestations. The myositis-specific autoantibodies (MSAs) are associated with phenotypic features and provide a tool for sub-classification of dermatomyositis patients. This review focuses on recent work characterizing the clinical features that accompany the MSAs in dermatomyositis. RECENT FINDINGS: There is increasing recognition of the distinct clinical and pathological phenotypes associated with each MSA. Most of these features display considerable overlap between MSA groups. Despite this, there are notable differences between the typical combinations of cutaneous and systemic manifestations, response to therapy, prognosis, and disease sequelae that define each dermatomyositis MSA group. The MSAs may ultimately improve diagnosis and sub-classification of dermatomyositis patients. However, more work is needed to understand the pathologic basis for much of the heterogeneity found within these subgroups.

PUF60: a prominent new target of the autoimmune response in dermatomyositis and Sjögren's syndrome.

OBJECTIVES: Autoantibodies are used clinically to phenotype and subset patients with autoimmune rheumatic diseases. We detected a novel 60 kDa autoantibody specificity by immunoblotting using a dermatomyositis (DM) patient's serum. Our objective was to identify the targeted autoantigen and to evaluate disease specificity and clinical significance of this new autoantibody. METHODS: A new 60 kDa specificity was detected by immunoblotting HeLa cell lysates. The targeted autoantigen was identified as poly(U)-binding-splicing factor 60 kDa (PUF60) using (i) a human protein array and (ii) two-dimensional gel electrophoresis and liquid chromatography tandem mass spectrometry peptide sequencing. Anti-PUF60 antibodies were assayed by ELISA using sera from patients with primary Sjögren's syndrome (SS; n=84), systemic lupus erythematosus (SLE; n=71), DM (n=267), polymyositis (n=45), inclusion body myositis (n=45) and healthy controls (n=38). RESULTS: PUF60 was identified as a new autoantigen. Anti-PUF60 antibodies were present in 25/84 (30%) patients with SS, 6/71 (8.5%) patients with SLE and 2/38 (5.0%) control subjects (SS vs controls, p=0.002; SLE vs controls, p=0.711). Anti-PUF60 antibodies were present in 48/267 (18.0%) patients with DM versus 4/45 (8.9%) and 5/45 (11.1%) patients with inclusion body myositis and polymyositis, respectively. The antibody was significantly associated with anti-Ro52 antibodies, rheumatoid factor and hyperglobulinemia in the patients with primary SS. In patients with DM, the antibody was associated with anti-transcription intermediary factor 1 gamma seropositivity and Caucasian race. CONCLUSIONS: PUF60 represents a novel autoantigen in patients with SS and DM. PUF60 antibodies are associated with distinct clinical features and different immune responses in different diseases.

Distinctive cutaneous and systemic features associated with antitranscriptional intermediary factor-1γ antibodies in adults with dermatomyositis.

BACKGROUND: Antibodies against transcriptional intermediary factor (TIF)-1γ are associated with malignancy in dermatomyositis (DM). Identification of clinical findings associated with anti-TIF-1γ antibodies in DM is a high priority for both patient diagnosis and risk assessment. OBJECTIVE: We sought to define the clinical phenotype of patients with anti-TIF-1γ DM. METHODS: Using a novel, sensitive, and specific assay for anti-TIF-1γ antibodies, we retrospectively tested plasma from 134 adult patients with DM and examined associations between anti-TIF-1γ antibodies and particular clinical and laboratory features. RESULTS: In all, 55 (41%) patients had autoantibodies to TIF-1γ. Anti-TIF-1γ positive patients were less likely to have systemic features including interstitial lung disease, Raynaud phenomenon, and arthritis/arthralgia. Patients with TIF-1γ autoantibodies had more extensive skin involvement, and some patients manifested characteristic findings including palmar hyperkeratotic papules, psoriasis-like lesions and a novel finding of hypopigmented and telangiectatic ("red on white") patches. LIMITATIONS: This was a retrospective study from a single tertiary referral center. CONCLUSION: TIF-1γ is the most commonly targeted DM-specific autoantigen in adults in a large US cohort. Although these patients tend to have less systemic involvement, their skin disease is often extensive and characteristic. Recognition of cutaneous findings in anti-TIF-1γ positive patients may allow more accurate and timely diagnosis and effective treatment of patients with DM.

Surgical treatment of systemic sclerosis--is it justified to offer peripheral sympathectomy earlier in the disease process?

PURPOSE: Systemic sclerosis (SSc) is a rare connective tissue disease associated with significant digital vasculopathy. Peripheral sympathectomy is frequently offered late in the disease process after severe digital ischemia has already occurred with patients being symptomatic for numerous years. The purpose of the present study was to analyze the results of peripheral sympathectomy in patients with a confirmed diagnosis of SSc. PATIENTS AND METHODS: A retrospective analysis of 17 patients (26 hands) who underwent peripheral sympathectomy between January 2003 and September 2013 was performed. Data regarding patient demographics, clinical features, and postoperative outcomes were retrieved. Of note, preoperative pain was present in all patients with a mean duration of 9.6 years prior to peripheral sympathectomy. RESULTS: Pain improvement/resolution was seen in 24 hands (92.3%). Digital ulcers healed in all patients with only two patients (two hands; 7.7%) requiring surgical intervention for ulcer recurrence 6 months and 4.5 years later. Minor complications were seen in seven hands (26.9%); including infection, wound opening, and stitch abscess, but none required surgical intervention. Seven of eight patients queried would have preferred surgical treatment at an earlier point in the disease process. CONCLUSION: Peripheral sympathectomy is a well-tolerated procedure in patients with SSc and is associated with predictable pain relief and ulcer healing in the majority of patients. In light of these findings it seems prudent to offer surgical treatment not as a last resort but rather earlier in the disease process to decrease the duration that patients suffer pain.

Amyopathic dermatomyositis: definitions, diagnosis, and management.

Amyopathic dermatomyositis can be a challenging diagnosis because patients lack traditional muscle findings. "Clinically amyopathic" dermatomyositis (CADM) accounts for the presence of subclinical muscle disease in some of these patients. These patients represent a substantial minority of dermatomyositis cases and have similar co-morbidities to "classic" dermatomyositis patients, including interstitial lung disease and malignancy. Clinically amyopathic dermatomyositis patients should not be considered as a distinct clinical entity from "classic" dermatomyositis, as they share antibody sub-types and associated co-morbidities, likely representing clinical spectrum of a common disease. It is essential for the clinician to be familiar with the clinical presentation of clinically amyopathic dermatomyositis, in order to facilitate early, accurate diagnosis and appropriate clinical management.

Most patients with cancer-associated dermatomyositis have antibodies to nuclear matrix protein NXP-2 or transcription intermediary factor 1γ.

OBJECTIVE: Since dermatomyositis (DM) is associated with an increased risk of malignancy, accurate identification of patients likely to harbor cancers is important. Using immunoprecipitations from radiolabeled cell lysates, several groups recently showed that anti-transcription intermediary factor 1γ (anti-TIF-1γ) antibodies are associated with malignancy in DM. We undertook this study to develop sensitive, specific assays to detect antibodies against TIF-1γ and nuclear matrix protein NXP-2 and to evaluate their association with malignancy in DM. METHODS: To detect anti-TIF-1γ antibodies, immunoprecipitations were performed using lysates made from HeLa cells overexpressing TIF-1γ, with detection by immunoblotting. Anti-NXP-2 antibodies were assayed by immunoprecipitation using (35) S-methionine-labeled NXP-2 generated by in vitro transcription/translation. We analyzed patient sera from DM cohorts seen at the Stanford University Dermatology Clinic (n = 111) and the Johns Hopkins Myositis Center (n = 102). RESULTS: A total of 17% and 38% of patients had antibodies against NXP-2 and TIF-1γ, respectively. Reactivity against either NXP-2 or TIF-1γ identified 83% of patients with cancer-associated DM. In addition to older age and male sex, cancer was associated with antibodies to NXP-2 or TIF-1γ on multivariate analysis (odds ratio 3.78 [95% confidence interval 1.33-10.8]). Stratification by sex revealed that anti-NXP-2 was specifically associated with cancer in males (odds ratio 5.78 [95% confidence interval 1.35-24.7]). CONCLUSION: These studies demonstrate that anti-NXP-2 and anti-TIF-1γ antibodies are frequent DM specificities (found in 55% of patients) and are present in most patients with cancer-associated DM.

International exchange on the clinical practice and research of rheumatic skin diseases: A report of the 5th International Conference of Cutaneous Lupus Erythematosus.

The 5th International Conference of Cutaneous Lupus Erythematosus was held in Tokyo, Japan on May 9 and 10, 2023. The latest topics on the pathogenesis, diagnosis, assessment, and treatment of cutaneous lupus erythematosus, dermatomyositis, and scleroderma (systemic sclerosis, morphea) were presented by experts in each field and new developments discussed. In these rheumatic skin diseases, many clinical trials of novel therapies targeting cytokines, signaling molecules, plasmacytoid dendritic cells, B cells, and other molecules are currently underway, and standardization of outcome assessment was discussed. In addition, the selection of the therapeutic agents available for the diversity of each case is becoming more important, together with the ongoing pathophysiological analysis of the diseases. The achievements of this conference will further promote the development of clinical practice and research in rheumatic skin diseases through international exchange among researchers. We hope that by reporting a summary of the conference in this manuscript, we can share its contents with readers.

Clinical Associations of Degos-Like Lesions in Patients With Systemic Sclerosis.

Importance: Degos-like lesions are cutaneous manifestations of a small-vessel vasculopathy that appear as atrophic, porcelain-white papules with red, telangiectatic borders. No study has adequately examined Degos-like lesions in patients with systemic sclerosis (SSc). Objective: To characterize the serologic, cutaneous, and internal organ manifestations associated with Degos-like lesions in a large cohort of patients with SSc. Design, Settings, and Participants: This retrospective cohort study involved adult patients with SSc who were seen at Stanford Rheumatologic Dermatology Clinic between January 1, 1998, and December 31, 2018. Participants fulfilled the 2013 classification criteria for SSc. Data analysis was conducted from February 1 to June 1, 2019. Main Outcomes and Measures: Data on demographic characteristics; autoantibody status; clinical characteristics, including cutaneous and systemic manifestations of SSc; and presence of Degos-like lesions were collected. Results: The cohort comprised 506 patients with SSc (447 females [88.3%]; mean [SD] age at first non-Raynaud disease symptoms, 46.1 [15.2] years). Twenty-seven patients (5.3%) had Degos-like lesions, of whom 24 (89.0%) had lesions affecting the fingers. Patients with Degos-like lesions were more likely to have diffuse cutaneous SSc compared with patients without lesions (15 [55.6%] vs 181 [37.8%]; P = .04). Degos-like lesions were also associated with acro-osteolysis (10 [37.0%] vs 62 [12.9%]; P < .01), digital ulcers (15 [55.6%] vs 173 [36.1%]; P = .04), and calcinosis (15 [55.6%] vs 115 [24.0%]; P < .01). While Degos-like lesions were not associated with internal organ manifestations, such as scleroderma renal crisis, interstitial lung disease, or pulmonary arterial hypertension, there was P < .10 for the association with gastric antral vascular ectasia. Conclusions and Relevance: Results of this study suggest an association of Degos-like lesions with diffuse cutaneous SSc and other cutaneous manifestations of vasculopathy, including acro-osteolysis, calcinosis, and digital ulcers. A prospective longitudinal study is warranted to examine the onset of Degos-like lesions and to elucidate whether these lesions play a role in SSc.

Skin disease in dermatomyositis.

PURPOSE OF REVIEW: This review will provide the clinician with an update on the pathogenesis, clinical manifestations, and therapy for skin disease in dermatomyositis. Recent insights into the role for interferon in skin disease as well as the development and validation of quantitative tools to measure skin disease activity allow the possibility that, for the first time, dermatomyositis skin disease can serve as a valid outcome for clinical trials of targeted therapies. Also, the increasing appreciation of the heterogeneity of skin disease in dermatomyositis has already provided evidence that clinical subtypes of disease can provide important prognostic and diagnostic information to the clinician. RECENT FINDINGS: It is becoming apparent that the skin inflammation alone has implications for systemic and malignancy risk in dermatomyositis patients, and that there may be several pathogenic similarities between muscle and skin inflammation in dermatomyositis. Recent data on therapy for calcinosis cutis highlights that more prospective studies are needed to evaluate how best to manage all manifestations of skin inflammation in dermatomyositis. SUMMARY: A more careful description and classification of skin disease in dermatomyositis may allow the clinician to predict more accurately which patients will be at higher risk for cancer, lung disease, or muscle inflammation. In addition, given the similarities in perturbed gene expression between skin and muscle tissue, it is likely that analysis of a more readily evaluable target organ such as skin might shed light on mechanisms of disease propagation throughout the body.

Autoantibodies and Cancer Association: the Case of Systemic Sclerosis and Dermatomyositis.

Several rheumatic diseases have a perplexing association with cancer. Unraveling this mysterious connection is likely to provide deeper understanding regarding mechanisms governing the onset of both autoimmunity and cancer immunity, in addition to providing clinicians much needed guidance around whom and when to screen for occult malignancy. Systemic sclerosis (scleroderma) and dermatomyositis are two diseases in which the association with internal malignancy is well-described and can be considered as models from which to gain important insights that likely have broader applicability. The past 15 years have witnessed a striking acceleration in understanding how these two diseases are related to cancer emergence-an important crack in this inscrutable armor has been the discovery and characterization of disease-specific autoantigens that are closely tied with risk of cancer emergence. The best-described examples of this are antibodies against anti-RNA polymerase III (anti-POL3) and transcription intermediary factor 1-gamma (anti-TIF1γ). Patients with systemic sclerosis and cancer that are diagnosed within a short time interval of each other frequently have anti-POL3 antibodies. Antibodies against the minor spliceosome protein RNA-Binding Region Containing 3 (RNPC3) are also associated with increased cancer incidence in systemic sclerosis. Similarly, in the dermatomyositis spectrum, the majority of anti-TIF1γ-associated cancers are detected around the time of DM onset (most often within 1 year). Antibodies against Nuclear Matrix Protein 2 are also potentially associated with increased cancer emergence in dermatomyositis. The systemic sclerosis/anti-POL3 connection with close cancer onset led to the first experiments directly supporting the concept that rheumatic disease may in fact be a manifestation of cancer. It is now clear that studying these diseases through the lens of autoantibodies can reveal relationships and insights that would otherwise remain obscured. Extending these studies, new findings show that antibodies against RNA polymerase I large subunit are associated with protection against short interval cancers in anti-POL3-positive systemic sclerosis patients. These insights highlight the fact that autoantigen discovery related to cancer emergence remains an important priority; such new tools will enable the testing of specific hypotheses regarding mechanisms governing disease emergence and development of effective anti-tumor responses. Autoantibody phenotype will likely play an important role in the development of cancer screening guidelines that are critically needed by clinicians taking care of these patients. In this review, we will summarize the current state of knowledge regarding the different ways in which autoantibodies are connected with systemic sclerosis/dermatomyositis and malignancy and highlight potential paths forward.