Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects

Association Between Autoantibody Phenotype and Cutaneous Adverse Reactions to Hydroxychloroquine in Dermatomyositis

Importance

Hydroxychloroquine sulfate is a commonly used medication for patients with dermatomyositis and has been associated with a uniquely elevated risk of adverse cutaneous reactions in this population. No studies to date have examined whether certain subsets of patients with dermatomyositis are at increased risk of experiencing a hydroxychloroquine-associated skin eruption.

Objective

To identify disease features that increase the risk of hydroxychloroquine-associated skin eruption in adults with dermatomyositis.

Design, Setting, and Participants

A retrospective cohort study was conducted in the outpatient dermatology clinic at a tertiary academic referral center. All adults with dermatomyositis (age >18 years) who started receiving hydroxychloroquine between July 1, 1990, and September 13, 2016, were eligible for the analysis. Patients were considered to have a hydroxychloroquine-associated skin eruption if a skin eruption had developed within their first 4 weeks of treatment and resolved with discontinuation of hydroxychloroquine therapy.

Exposures

One or more doses of hydroxychloroquine.

Main Outcomes and Measures

The associations between autoantibodies (against transcription intermediary factor 1γ [TIF-1γ], nucleosome-remodeling deacetylase complex [Mi-2], nuclear matrix protein [NXP-2], small ubiquitinlike modifier 1 activating enzyme [SAE-1/2], melanoma differentiation-associated gene 5 [MDA-5], histidyl-transfer RNA synthetase [Jo-1], Ku, and signal recognition particles) and cutaneous adverse reactions to hydroxychloroquine in patients with dermatomyositis.

Results

A total of 111 patients met the inclusion criteria, and 23 (20.7%) developed a hydroxychloroquine-associated skin eruption (20 [87.0%] were women with a mean [SD] age of 49 [14] years at diagnosis). Skin eruptions were approximately 3 times more common in patients with anti-SAE-1/2 autoantibodies (7 of 14 [50.0%]) compared with those without the autoantibody (16 of 97 [16.5%]). In contrast, none of 15 patients with anti-MDA-5 autoantibodies had a skin eruption vs 23 of 96 (24.0%) of those without the autoantibody. In exact logistic regressions adjusted for age, race/ethnicity, sex, amyopathic status, anti-Ro52 status, and dermatomyositis-associated cancer, the presence of anti-SAE-1/2 autoantibodies was significantly associated with a hydroxychloroquine-associated skin eruption (odds ratio [OR], 8.43; 95% CI, 1.98-49.19; P = .003) and presence of anti-MDA-5 autoantibodies was significantly negatively associated with a hydroxychloroquine-associated skin eruption (OR, 0.06; 95% CI, 0.0004-0.52; P = .006). No other autoantibodies were significantly positively or negatively associated with a hydroxychloroquine-associated skin eruption.

Conclusions and Relevance

Adverse skin reactions to hydroxychloroquine are relatively common in a US cohort of patients with dermatomyositis. Our data suggest that pathophysiologic differences exist between autoantibody subsets in dermatomyositis.

Developing classification criteria for skin-predominant dermatomyositis: the Delphi process

BACKGROUND

The European League Against Rheumatism/American College of Rheumatology classification criteria for inflammatory myopathies are able to classify patients with skin-predominant dermatomyositis (DM). However, approximately 25% of patients with skin-predominant DM do not meet two of the three hallmark skin signs and fail to meet the criteria.

OBJECTIVES

To develop a set of skin-focused classification criteria that will distinguish cutaneous DM from mimickers and allow a more inclusive definition of skin-predominant disease.

METHODS

An extensive literature review was done to generate items for the Delphi process. Items were grouped into categories of distribution, morphology, symptoms, antibodies, histology and contextual factors. Using REDCap™, participants rated these items in terms of appropriateness and distinguishing ability from mimickers. The relevance score ranged from 1 to 100, and the median score determined a rank-ordered list. A prespecified median score cut-off was decided by the steering committee and the participants. There was a pre-Delphi and two rounds of actual Delphi.

RESULTS

There were 50 participating dermatologists and rheumatologists from North America, South America, Europe and Asia. After a cut-off score of 70 during the first round, 37 of the initial 54 items were retained and carried over to the next round. The cut-off was raised to 80 during round two and a list of 25 items was generated.

CONCLUSIONS

This project is a key step in the development of prospectively validated classification criteria that will create a more inclusive population of patients with DM for clinical research. What's already known about this topic? Proper classification of patients with skin-predominant dermatomyositis (DM) is indispensable in the appropriate conduct of clinical/translational research in the field. The only validated European League Against Rheumatism/American College of Rheumatology criteria for idiopathic inflammatory myopathies are able to classify skin-predominant DM. However, a quarter of amyopathic patients still fail the criteria and does not meet the disease classification. What does this study add? A list of 25 potential criteria divided into categories of distribution, morphology, symptomatology, pathology and contextual factors has been generated after several rounds of consensus exercise among experts in the field of DM. This Delphi project is a prerequisite to the development of a validated classification criteria set for skin-predominant DM.

Recent Advances in Pharmacological Treatments of Adult Dermatomyositis

PURPOSE OF THE REVIEW

Dermatomyositis (DM) is an uncommon autoimmune disease that primarily affects the skin, muscle, and/or lungs, and remains a therapeutic challenge. We discuss recent studies evaluating efficacy of conventional treatments for clinically amyopathic DM (CADM), DM-associated interstitial lung (ILD) disease, and classic DM (CDM). We highlight several emerging new therapies with a focus on clinical trials, systematic reviews, and case series in the last 5 years.

RECENT FINDINGS

Recent studies report a significant number of patients remain refractory to antimalarials and require second- and third-line agents. Effective treatment for DM-associated ILD can vary based on patient specific antibodies. CDM requires oral glucocorticoids; recent studies have evaluated the benefits of adjunctive therapies including methotrexate and calcineurin inhibitors. New therapies target cell populations or cytokines thought to drive disease pathogenesis. Dermatomyositis is an autoimmune disease that remains challenging to treat. Many patients are refractory to conventional therapies, warranting the development and evaluation of new treatments.

Clinical features of patients with anti-melanoma differentiation-associated gene-5 antibody-positive dermatomyositis complicated by spontaneous pneumomediastinum

BACKGROUND

Dermatomyositis (DM) with autoantibody against melanoma differentiation-associated gene-5 (MDA5) is characterized by elevated risk of rapidly progressive interstitial lung disease (RP-ILD) with a potentially fatal course. Pneumomediastinum (PNM) is a common pulmonary manifestation which accompanies ILD. However, the clinical features of the patients with anti-MDA5 antibody-positive DM who develop PNM remain unclear.

METHODS

We retrospectively examined 31 patients with DM having anti-MDA5 antibody and compared the clinical features between patients with PNM (PMN(+)) (n = 11) and those without (PNM(-) (n = 20). In addition, we evaluated the treatment-related prognoses in PNM(+) group.

RESULTS

CT score (total ground-glass opacity (GGO) score, P = 0.02; total fibrosis score, P = 0.02) before treatment, and mortality (P = 0.04) were significantly higher in PNM(+) group. The cumulative survival rate as assessed by Kaplan-Meier method was significantly lower for the PNM(+) group (P = 0.02). Among 11 PMN(+) patients, 9 patients (9/11, 81.8%) underwent intensive immunosuppression therapy for RP-ILD, and 5 patients (5/11, 45.5%) did not respond to it and died from the respiratory failure. At the time of diagnosis of PNM, nonsurvivors had worse liver function (ALT, P = 0.03; LDH, P = 0.01), worse respiratory status (A-aDO2, P = 0.01), and worse CT score (total GGO score, P < 0.01).

CONCLUSIONS

A subgroup of patients with DM having anti-MDA5 antibody complicated by PNM as well as RP-ILD did respond to intensive immunosuppression therapy. Initial aggressive immunosuppressive therapy should be considered for these patients.Key Points• This study clearly demonstrate the presence of PNM was associated with elevated risk of death due to respiratory failure from RP-ILD among patients with DM having circulating anti-MDA5-antibody.•This study demonstrate evaluation of CT image may be helpful to find patients with better response to the intense immunosuppression therapy for the patients with DM having circulating anti-MDA5-antibody and PNM.

Factors Associated With Clinical Remission of Skin Disease in Dermatomyositis

Importance

Cutaneous disease represents a significant burden for patients with dermatomyositis. However, quantitative estimates of the probability of skin disease remission and clinical factors associated with skin outcomes are lacking.

Objective

To characterize cutaneous disease course in adult patients with dermatomyositis.

Design, Setting, and Participants

Prospective cohort study conducted at a dermatology clinic at a tertiary academic referral center. All adult patients with dermatomyositis (age >18 years) seen between May 15, 2007, and October 28, 2016, were eligible. Patients were included in the current analysis if they had a baseline Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) activity score of 12 or higher, and 2 or more CDASI scores separated by 3 months or more within their first 3 years of follow-up.

Main Outcomes and Measures

The percentage of patients who achieved clinical remission of their cutaneous disease as measured by the CDASI over a 3-year follow-up.

Results

A total of 74 patients met our inclusion criteria (mean [SD] age at initial CDASI scoring, 54 [13] years; 58 women [78%]), and 28 (38%) achieved clinical remission during our 3-year follow-up period. Increased age (odds ratio [OR], 1.07; 95% CI, 1.02-1.12; P = .01), a dermatomyositis-associated malignancy (OR, 14.46; 95% CI, 2.18-96.07; P = .01), and treatment with mycophenolate mofetil (OR, 6.00; 95% CI, 1.66-21.78; P = .01) were significantly associated with clinical remission of skin disease in multivariable analysis. Patients with anti-melanoma differentiation-associated protein 5 antibodies had a significantly lower probability of meeting outcome criteria in our time-to-event analysis. Baseline cutaneous disease activity, disease duration at baseline, and disease duration before first systemic therapy were not significantly associated with clinical remission of skin disease.

Conclusions and Relevance

Clinical remission was relatively uncommon in our population despite aggressive systemic therapy, and patients with anti-melanoma differentiation-associated protein 5 antibodies were even less likely to enter clinical remission during a 3-year follow-up period. Although mycophenolate mofetil compared favorably with other treatment options, our data provide evidence that a substantial population of patients with dermatomyositis have skin disease that is not adequately managed with standard-of-care therapies.

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.

Geospatial Correlation of Amyopathic Dermatomyositis With Fixed Sources of Airborne Pollution: A Retrospective Cohort Study

Objective: Dermatomyositis (DM) may result from exogenous triggers, including airborne pollutants, in genetically susceptible individuals. The United States Environmental Protection Agency's 2011 National Air Toxics Assessment (NATA) models health risks associated with airborne emissions, available by ZIP code tabulation area (ZCTA). Important contributors include point (fixed), on-road, and secondary sources. The objective of this study was to investigate the geospatial distributions of DM and subtypes, classic DM (CDM) and clinically amyopathic DM (CADM), and their associations with airborne pollutants.

Methods: This retrospective cohort study identified 642 adult DM patients from 336 unique ZCTAs. GeoDa v.1.10 was used to calculate global and local Moran's indices and generate local indicator of spatial autocorrelation (LISA) maps. All Moran's indices and LISA maps were permuted 999 times.

Results: Univariate global Moran's indices for DM, CDM, and CADM prevalence were not significant, but LISA maps demonstrated differential local spatial clustering and outliers. CADM prevalence correlated with point sources (bivariate global Moran's index 0.071, pseudo-p = 0.018), in contrast to CDM (−0.0053, pseudo-p = 0.46). Bivariate global Moran's indices for DM, CDM, and CADM prevalence did not correlate with other airborne toxics, but bivariate LISA maps revealed local spatial clustering and outliers.

Conclusion: Prevalence of CADM, but not CDM, is geospatially correlated with fixed sources of airborne emissions. This effect is small but significant and may support the hypothesis that triggering exposures influence disease phenotype. Important limitations are NATA data and ZCTA population estimates were collected from 2011 and ZCTA of residence may not have been where patients had greatest airborne pollutant exposure.

Pruritus in patients with amyopathic dermatomyositis

Amyopathic dermatomyositis has been associated with the exposure to several drugs: the article by Jeimy et al. described the onset of this uncommon disease in a patient treated with omalizumab. Paradoxically, this patient complained of an intense pruritus and this finding has been reported by several authors observing patients with amyopathic dermatomyositis.

The spectrum and clinical significance of myositis-specific autoantibodies in Chinese patients with idiopathic inflammatory myopathies

OBJECTIVES

The aim of this study is to analyze the prevalence of myositis-specific autoantibodies (MSAs) and to elucidate their associations with clinical features in Chinese patients with polymyositis (PM) and dermatomyositis (DM).

METHODS

Twelve subsets of MSAs including anti-Mi-2, anti-TIF1-γ, anti-MDA5, anti-NXP2, anti-SAE1, anti-SRP, anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ, anti-OJ, and anti-HMGCR antibodies were tested. Four hundred and ninety-seven PM/DM patients were enrolled. Clinical features and laboratory data were collected. The frequency of MSAs and the correlations with clinical phenotypes were calculated by SPSS 21.0.

RESULTS

MSAs were present in 65.4% in PM/DM patients. Anti-TIF1-γ (14.3%), anti-MDA5 (12.5%), and anti-Jo-1 (10.1%) were the three commonest MSAs. Anti-SAE1 (OR 14.877, 95% CI 1.427-155.074), anti-SRP (OR 4.339, 95% CI 1.529-12.312) and anti-TIF1-γ (OR 2.790, 95% CI 1.578-4.935) were associated with dysphagia. In contrast, anti-MDA5 (OR 0.356, 95% CI 0.148-0.856) might decrease the frequency of this manifestation. Interstitial lung disease (ILD) was observed more frequently in patients carrying anti-EJ (OR 14.202, 95% CI 1.696-118.902), anti-Jo-1 (OR 11.111, 95% CI 3.306-37.335), and anti-MDA5 (OR 3.109, 95% CI 1.578-6.128). On the contrary, anti-Mi-2 (OR 0.180, 95% CI 0.055-0.589), anti-TIF1-γ (OR 0.163, 95% CI 0.080-0.333), and anti-HMGCR (OR 0.058, 95% CI 0.007-0.451) were protective factors against developing ILD. Anti-TIF1-γ was an independent risk factor for cancer-associated myositis (OR 4.237, 95% CI 1.712-10.487).

CONCLUSIONS

PM/DM patients had high frequencies of MSAs. Several MSAs were independent factors in determining unique clinical phenotypes.

The diagnosis and classification of amyopathic dermatomyositis: a historical review and assessment of existing criteria

BACKGROUND

Diagnostic criteria are used to identify a patient having a disease in a clinical setting, whereas classification criteria create a well-defined population for research purposes. The diagnosis and classification of amyopathic dermatomyositis (ADM) have not been recognized by most existing criteria for idiopathic inflammatory myopathies (IIMs). To address this, several criteria were proposed to define ADM either as a distinct disease entity or as a subset of the spectrum of IIMs.

OBJECTIVES

To discuss the diagnosis and classification of ADM and to assesses the available criteria in identifying cases of ADM and/or distinguishing it from dermatological mimickers such as lupus erythematosus.

METHODS

We conducted an extensive literature search using the PubMed database from June 2016 to August 2018, using the search terms 'amyopathic dermatomyositis', 'diagnosis' and 'classification'.

RESULTS

The European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, which are the only validated classification criteria for adult and juvenile IIM and their major subgroups, include three cutaneous items (Göttron sign, Göttron papules, heliotrope rash) to be able to classify ADM. This international and multispecialty effort is a huge step forward in the classification of skin-predominant disease in dermatomyositis. However, about 25% of the population with ADM do not meet two out of the three skin features and are misdiagnosed or classified as having a different disease entity, most commonly lupus erythematosus.

CONCLUSIONS

These gaps rationalize the continuous assessment and improvement of existing criteria and/or the development of validated, separate and skin-focused criteria for DM.

Efficacy and safety of oral high-trough level tacrolimus in acute/subacute interstitial pneumonia with dermatomyositis

OBJECTIVES

We assessed the efficacy and safety of combination therapy with glucocorticoids and high-trough level tacrolimus (TAC) for the treatment of acute/subacute interstitial pneumonia (A/SIP) in patients with dermatomyositis (DM).

METHODS

Eleven DM-A/SIP patients were enrolled. The combination therapy with glucocorticoids and TAC was started as early as possible after DM-A/SIP was diagnosed. We monitored the trough concentration of TAC. In the initial 3 months, we maintained the trough concentration of TAC at relatively high levels within a range of 15-20 ng/mL. Then, we decreased the TAC doses stepwise to keep the trough concentration at 10-15 ng/mL in the next 3 months and 5-10 ng/mL as a maintenance dose.

RESULTS

Seven patients had clinically amyopathic DM. Six patients were positive for anti-aminoacyl-tRNA synthetase antibody and two were positive for anti-melanoma differentiation-associated gene 5 antibody. Ten patients survived for the period of the 24-week follow up. One patient died under a tentative diagnosis of viral encephalitis at 4 months after the treatment. In the 10 surviving patients, interstitial pneumonia improved in eight patients and was not worse in two patients. Clinical examinations, including the Krebs von den Lungen-6 levels, % forced vital capacity, and chest computed tomography score, were significantly improved by this combination therapy. Although grade 1 and 2 renal damage occurred in 4 and 2 patients, respectively.

CONCLUSIONS

The present findings suggest that early therapeutic intervention by a combination with glucocorticoids and initial high-trough level TAC is effective for DM-A/SIP although consideration of the risks of infection and renal damage is required.

Oral cyclophosphamide in treatment of patients with refractory idiopathic inflammatory myopathies: a retrospective observational study

To describe the use of oral cyclophosphamide (PO CYC) in a single center longitudinal cohort of patients with idiopathic inflammatory myopathies (IIM). Patients using PO CYC were identified through a retrospective chart review of a myositis cohort at a single academic center. PO CYC dose, duration, adverse events, and disease activity measures before and after CYC were analyzed. Disease activity measures included muscle enzymes, manual muscle testing (MMT8), 100-mm visual analog scale (VAS), and 1-4 Likert scale for physician global assessment. Fourteen patients were treated with PO CYC within the cohort between 2008 and 2017; 9 dermatomyositis (DM), 3 polymyositis (PM), and 2 with immune-mediated necrotizing myopathy (IMNM). Age was 51.1 (40-72) years and the cumulative dose of PO CYC was 41 (2-131) grams over duration of 12.4 (0.5-43) months, mean (range) for all. All patients had severe refractory IIM, 10 (72%) with ILD, 3 (21%) with cardiac involvement and 4 (29%) were dependent in most activities of daily living. Median number of prior failed therapies was 4.5 (range 3-6) including intravenous CYC in 5 patients. Disease activity measures significantly improved following CYC use and concomitant daily prednisone dose decreased. The most common adverse events during CYC therapy were infections. We report the first cohort study of PO CYC use in IIM patients with severe, treatment refractory disease. Further trials are needed to verify these results as well as to evaluate long-term safety outcomes.

Itch in dermatomyositis: the role of increased skin interleukin-31

BACKGROUND

Interleukin (IL)-31 is implicated in pruritus associated with pruritic skin diseases like atopic dermatitis. Although pruritus is a prominent feature in dermatomyositis (DM), few studies have evaluated the pathogenesis of DM-associated itch.

OBJECTIVES

To establish the prevalence of itch in DM, and to investigate the role of IL-31 in DM-related itch.

METHODS

Pruritus and disease activity of DM were evaluated by a visual analogue scale (VAS) and the Cutaneous Disease and Activity Severity Index (CDASI), respectively. Expression of IL-31 and IL-31 receptor alpha (IL-31RA) in lesional DM, nonlesional DM and healthy control skin was evaluated by quantitative reverse-transcriptase polymerase chain reaction and immunofluorescence. Flow cytometry was performed on skin cells isolated from lesional DM skin to identify cellular sources of IL-31 in DM.

RESULTS

Among 191 patients with DM, 50·8% had moderate-to-severe itch, and itch was correlated with increased cutaneous severity (r = 0·34). In patients with itchy DM, gene expression of IL31 and IL31RA in lesional skin was upregulated compared with nonlesional skin and healthy control skin. IL31 mRNA expression positively correlated with VAS itch score (r = 0·67). On immunofluorescence, immunoreactivity for IL-31 and IL-31RA was stronger in lesional skin. Flow cytometry showed that lesional DM skin contained significantly more IL-31-producing cells, and CD4⁺ cells were the most common cell type. Lenabasum, an emerging treatment for DM, significantly downregulated IL-31 from CpG-stimulated peripheral blood mononuclear cells.

CONCLUSIONS

Increased skin IL-31 may play a role in DM-associated itch, and ongoing trials will evaluate the effects of systemic treatment on IL-31 and itch in DM.

Differential clinical features of patients with clinically amyopathic dermatomyositis who have circulating anti-MDA5 autoantibodies with or without myositis-associated autoantibodies

BACKGROUND

Anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies have been identified as myositis-specific autoantibodies that are often associated with clinically amyopathic dermatomyositis (CADM) and a poor prognosis due to rapidly progressive interstitial lung disease (RP-ILD) in East Asian patients. Besides anti-MDA5 autoantibodies, patients with CADM may have myositis-associated autoantibodies (MAAs), which characterize other connective tissue diseases such as rheumatoid arthritis and Sjögren's syndrome. However, the clinical significance of the coexistence of anti-MDA5 autoantibodies and MAAs in patients with CADM remains unclear.

METHODS

We retrospectively analyzed 24 patients with CADM who had anti-MDA5 autoantibodies. Their clinical phenotypes including laboratory test results, high-resolution lung computed tomography data, response to therapy, and prognosis were compared between those who were positive and negative for MAAs, such as antinuclear antibody (ANA), anti-cyclic citrullinated peptide (CCP), anti-SSA, and anti-SSB antibodies.

RESULTS

Among 24 patients, 9 (37.5%) additionally had at least one of the MAAs examined in this study: 1 patient was positive for ANA, 5 for anti-CCP, 5 for either anti-SSA or anti-SSB, 1 for anti-cardiolipin, and 1 for anti-Scl-70. Although all anti-MDA5-positive patients with CADM had ILD, the MAA-positive patients showed a lower risk of developing RP-ILD (p = 0.03), a more favorable response to combination therapy of corticosteroids and immunosuppressive agents, and a lower mortality rate than patients with no MAAs (p = 0.03).

CONCLUSIONS

Our data suggest that anti-MDA5-positive patients with CADM who also have MAAs have a better prognosis than those without MAAs; thus, anti-MDA5 autoantibodies by themselves may not be strong predictors of worse clinical outcomes in patients with CADM. Coexistent MAAs could be biomarkers for a favorable prognosis in anti-MDA5-positive patients with CADM.

Potential of Krebs von den Lungen-6 as a predictor of relapse in interstitial pneumonia with anti-aminoacyl tRNA synthetase antibodies-positive dermatomyositis

OBJECTIVE

To identify a predictor of relapse in interstitial pneumonia (IP) in patients with anti-aminoacyl tRNA synthetase antibodies-positive dermatomyositis (ARS-DMIP).

METHODS

This retrospective cohort study comprised 27 ARS-DMIP patients. We compared clinical and laboratory findings between the relapse and non-relapse groups during 2 years after treatment initiation to find predictors of relapse in IP. Candidate predictors were further assessed by analysing the relationship with the relapse of IP.

RESULTS

One patient with ARS-DMIP died. About 7 (26.9%) of the remaining 26 patients with ARS-DMIP had a relapse of IP. We found that the levels of serum Krebs von den Lungen-6 (KL-6) in the relapse group were significantly higher than those in the non-relapse group at the time points before treatment (P = .046) and after treatments, including 6 (P = .004), 12 (P = .013), 18 (P = .003) and 24 months (P < .001). The KL-6 values that maximised the area under the ROC curve were 2347 U/mL before treatment, 622 U/mL after 6 months and 468 U/mL after 12 months. The relapse rates after 104 weeks were significantly higher in patients with KL-6 levels ≥2400 U/mL before treatment (P = .014), ≥600 ng/mL after 6 months (P < .005) and ≥470 U/mL after 12 months (P = .010).

CONCLUSION

These findings suggest that the levels of KL-6 before and after treatment in ARS-DMIP may represent the disease activity of IP, and they may be useful as the predictor of relapse in IP in patients with ARS-DMIP.

Cutaneous and Systemic Findings Associated With Nuclear Matrix Protein 2 Antibodies in Adult Dermatomyositis Patients

OBJECTIVE

To characterize the cutaneous and systemic clinical phenotype of dermatomyositis patients with antinuclear matrix protein 2 (anti-NXP-2) antibodies.

METHODS

We conducted a retrospective cohort analysis of 178 dermatomyositis patients seen at the Stanford University Clinic. An electronic chart review employing a keyword search strategy was performed to collect clinical and laboratory data. Anti-NXP-2 antibodies were assayed by immunoprecipitation using NXP-2 produced by in vitro transcription/translation.

RESULTS

Antibodies to NXP-2 were detected in 20 of the 178 patients (11%). Anti-NXP-2 antibodies were associated with male sex (50% versus 25%; P = 0.02), dysphagia (74% versus 39%; P = 0.006), myalgia (89% versus 52%; P = 0.002), peripheral edema (35% versus 11%; P = 0.016), and calcinosis (37% versus 11%; P = 0.007). These patients were less likely to be clinically amyopathic (5% versus 23%; P = 0.08). Five of the 20 patients with anti-NXP-2 antibodies (25%) had an associated internal malignancy. No other cutaneous characteristics were associated with anti-NXP-2 antibodies, except a decreased frequency of Gottron's sign (44% versus 75%; P = 0.012) and a greater likelihood of having mild skin disease.

CONCLUSION

Dermatomyositis patients with anti-NXP-2 antibodies have a distinct and often severe systemic phenotype that includes myalgia, peripheral edema, and significant dysphagia, despite having milder inflammatory skin disease.

Clinical effects of direct hemoperfusion using a polymyxin B-immobilized fiber column in clinically amyopathic dermatomyositis-associated rapidly progressive interstitial pneumonias

Background

Rapidly progressive interstitial pneumonias (RPIPs) associated with clinically amyopathic dermatomyositis (CADM) are highly resistant to therapy and have a poor prognosis. Multimodal therapies, including direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX-DHP), have a protective effect on RPIPs. We evaluated the effects of PMX-DHP on CADM-associated RPIPs.

Methods

We retrospectively enrolled 14 patients with CADM-associated RPIPs and acute respiratory failure treated with PMX-DHP, corticosteroids, and immunosuppressive agents. Clinical manifestations were compared between survivors and non-survivors at 90 days after PMX-DHP.

Results

The survival rate at 90 days after PMX-DHP was 35.7% (5/14). Before PMX-DHP, the survivor group exhibited a significantly higher PaO₂/FiO₂ (P/F) ratio and serum surfactant protein-D (SP-D) levels and significantly lower lactate dehydrogenase (LDH) and ferritin levels than the non-survivor group. Platelet counts were significantly decreased after PMX-DHP therapy in both groups, but remained higher in the survivor group than the non-survivor group over the course of treatment. Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody positive patients demonstrated a poor 90-day survival rate, lower platelet counts and P/F ratio, and higher LDH levels than anti-MDA-5 antibody negative patients.

Conclusions

CADM-associated RPIPs with anti-MDA-5 antibody is associated with a very poor prognosis. A higher P/F ratio and SP-D level, lower LDH and ferritin levels, higher platelet counts, and anti-MDA-5 antibody negativity are important prognostic markers in patients with CADM-associated RPIPs treated with PMX-DHP.

Multiple values of 18F-FDG PET/CT in idiopathic inflammatory myopathy

This study aimed to investigate the multiple values of ¹⁸F-FDG PET/CT in detecting malignant tumors, evaluating myopathy, and determining interstitial lung disease in patients with idiopathic inflammatory myopathy (IIM). We retrospectively analyzed the data of 38 patients who were examined by ¹⁸F-FDG PET/CT and eventually diagnosed as IIM. We also collected the data of another 22 cases with negative PET/CT as the control. Pulmonary HRCT images were acquired simultaneously with regular ¹⁸F-FDG PET/CT imaging for each patient. Image analysis included the presence of malignant lesions, muscular FDG uptake, and interstitial lung disease and its imaging features. IIM was classified into polymyositis (PM), classic dermatomyositis (CDM), and clinical amyopathic dermatomyositis (CADM). All suspected malignant lesions were confirmed by histopathological examination. Interstitial lung disease was diagnosed by HRCT. Rapidly progressive interstitial lung disease (RP-ILD) was determined according to clinical follow-ups. The significance of ¹⁸F-FDG PET/CT in the detection of malignancy, observation of activity of myopathy, and determination of interstitial lung disease in IIM patients was explored based on the final clinical diagnosis. In the 38 patients with IIM, 3 cases were classified as PM, 18 as CDM, and 17 as CADM. PET/CT correctly detected 7 cases (18.4%) of malignant tumors, and all of which were found in CDM and PM patients. The muscular FDG uptake in IIM patients was higher than the control population, and it was higher in patients with myopathy (including PM and CDM) than in patients with CADM. The muscular FDG uptake in IIM patients was correlated with elevated serum creatine kinase level (r = 0.332, P = 0.042) and impaired muscle strength (r = -0.605, P < 0.001). Interstitial lung disease was detected by HRCT in 30 patients (78.9%), and 7 of them were eventually confirmed as RP-ILD, according to the clinical outcome. The FDG uptake in lung lesions of RP-ILD patients was higher than those with chronic interstitial lung diseases, even though no significant difference was found between the CT features of RP-ILD and chronic interstitial lung disease. When SUV_max ≥ 2.4 was employed as the threshold for RP-ILD prediction, the diagnostic efficiency was yield with a sensitivity of 100.0% (7/7), specificity of 87.0% (20/23), and accuracy of 90.0% (27/30), respectively. For IIM patients, ¹⁸F-FDG PET/CT has multiple values in identifying malignancies, observing the status of inflammatory myopathy, detecting interstitial lung disease, and predicting the occurrence of RP-ILD. Therefore, it is recommended to use PET/CT in the clinical course of diagnosis and management of IIM.

Evaluation of clinical prognostic factors for interstitial pneumonia in anti-MDA5 antibody-positive dermatomyositis patients

OBJECTIVES

We retrospectively investigated clinical prognostic factors for interstitial pneumonia (IP) in anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive dermatomyositis (DM) patients.

METHODS

Subjects comprised 18 patients with anti-MDA5 Ab-positive DM-IP (9 survivors; 9 deaths).

RESULTS

Initial serum albumin levels, ferritin levels, and ground-glass opacity (GGO) scores in the right middle lobes were significantly higher in the death group than in the survivor group (p = .033, .013, and .005, respectively). Initial alveolar-arterial oxygen gradient (P[A-a]O₂) was also higher in the death group than in the survivor group (p = .064). Initial serum ferritin, P[A-a]O₂, and right middle lobe GGO score were found to significantly relate to death. Survival rates after 24 weeks were significantly lower among patients with an initial ferritin level of ≥450 ng/mL (25%), P[A-a]O₂ of ≥30 mmHg (31%), and a right middle lobe GGO score of ≥2 (11%) than each of the others (p = .006, .020, and .002, respectively).

CONCLUSIONS

An initial serum ferritin level of ≥450 ng/mL, P[A-a]O₂ of ≥30 mmHg, and right middle lobe GGO score of ≥2 (GGO ≥5% of the lobe) were identified as poor prognostic factors for anti-MDA5 Ab-positive DM-IP patients.

Chemokine profiles of interstitial pneumonia in patients with dermatomyositis: a case control study

Chemokines play an important role in the pathophysiology of dermatomyositis (DM) with interstitial pneumonia (IP). However, the relation between chemokines and the disease activity or prognosis of DM-IP has not been elucidated. We evaluated the serum C-C motif chemokine ligand (CCL) 2, Th1 chemokines (C-X-C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11), and Th2 chemokine (CCL17) profiles of 30 patients, and examined the relation between these chemokines and the disease activity or prognosis of DM-IP. Initial serum CCL2 level was higher in the death group (P = 0.007). To determine the cut-off points effective as poor prognostic factors of DM-IP, ROC curve analysis was carried out on initial serum CCL2 level. The value that maximized the area under the ROC curve was 894 pg/mL (sensitivity: 100%, specificity: 70.8%). Serum CCL2, CXCL9, CXCL10, and CXCL11 levels were lower at 2 weeks after treatment initiation than before treatment. Serum CCL2, CXCL10, and CXCL11 levels at 2 weeks after treatment initiation were higher in the death group. Serum levels of chemokines such as CCL2, CXCL10, and CXCL11 may be possible biomarkers of disease activity and prognosis in DM-IP, and serum CCL2 level may be useful when deciding initial treatment.

Clinical and Dermoscopic Features of the Scalp in 31 Patients with Dermatomyositis

BACKGROUND

Scalp involvement is not directly evaluated in patients with dermatomyositis (DM). Therefore, the exact frequency of scalp dermatomyositis (SDM) and its clinical and trichoscopic characteristics have been poorly described.

OBJECTIVE

The aim of this study was to determine the frequency and clinical and dermoscopic features of SDM in patients diagnosed with DM.

METHODS

We performed a descriptive prospective, cross-sectional observational study that included all patients diagnosed with DM at a Mexican academic institute over the course of a year.

RESULTS

Twenty-four out of 31 patients with DM had scalp involvement at clinical examination, with a prevalence of 77.4%. SDM was clinically characterized by erythema in all cases, scales in 20 (83.3%) patients, nonscarring alopecia in 21 (87.5%) patients, pruritus in 17 (70.8%) patients, and poikiloderma of the scalp in 16 (51.6%) patients. Twenty-eight patients were evaluated by trichoscopy. The most consistent finding was the presence of enlarged capillaries, found in 20 (71.4%) cases, followed by peripilar casts (57.1%) and tufting and interfollicular scales in 14 (50%) cases. Twenty-two patients also had positive nail fold capillaroscopic features similar to those observed by trichoscopy.

LIMITATIONS

The simple size was limited.

CONCLUSIONS

Scalp involvement and alopecia are common in patients with DM, and trichoscopy shows features similar to those found at capillaroscopy. Trichoscopy is a very important tool for diagnosis of scalp involvement in patients with DM.

Inflammatory Myopathies with Cutaneous Involvement: from Diagnosis to Therapy

The group of idiopathic inflammatory myopathies (IIM) include various disorders of skeletal muscles with or without skin involvement. The most common types are dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and necrotizing autoimmune myopathy (NAM). Dermatomyositis subdivides into various clinical forms such as juvenile, amyopathic or paraneoplastic dermatomyositis, scleromyositis, overlap or anti-synthetase syndromes, etc.

Recently, numerous new antibodies defining the characteristic clinical phenotype have been described as anti-MDA5 antibodies associated with interstitial lung disease and amyopathic dermatomyositis or anti-TIF1γ antibodies as markers for paraneoplastic dermatomyositis. Moreover, new clinical entities as drug-induced dermatomyositis are presumed, since some medications may induce, or trigger inflammatory myopathies.

Knowledge of the complex methods and techniques required to diagnose the disease is of great importance in clinical practice. The variety of clinical variants needs diagnosis because of the differing prognosis and therapeutic modalities.

The skin in autoimmune diseases-Unmet needs

Treatment of skin manifestations in systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis (DM) is based on the results of only few randomized controlled trials. The first-line treatment for disfiguring and widespread cutaneous involvement in SLE is antimalarials, but some patients are therapy resistant. Recently, the monoclonal antibody belimumab was approved for SLE as an adjunct therapy for patients with autoantibody-positive disease who despite standard therapy show high disease activity, intolerance of other treatments, or an unacceptably high need for corticosteroids. However, a validated skin score has not been used to confirm the efficacy of belimumab on mucocutaneous manifestations. In SSc, another multi-systemic progressive disease, involvement of the lung, kidney, and the heart is frequently treated with corticosteroids and immunosuppressives, but therapeutic modalities for cutaneous lesions, such as skin sclerosis and digital ulcers, are limited. In the past years, treatment with the endothelin-receptor antagonist bosentan has been proven to reduce the occurrence of new digital ulcers in SSc patients but has no or limited effect on healing of digital ulcers. DM is an idiopathic autoimmune disease characterized by inflammation of the muscles and skin, which is treated with immunosuppressives. Corticosteroids are the first-line treatment for muscle involvement in DM, but skin lesions often flare by reduction or discontinuation. In summary, there is a high unmet need for new therapeutic strategies focusing on skin involvement in systemic autoimmune diseases. Therefore, innovative designs of randomized controlled trials with validated skin scores are warranted to develop new therapeutic strategies for patients with cutaneous manifestations.

Gottron Papules and Gottron Sign with Ulceration: A Distinctive Cutaneous Feature in a Subset of Patients with Classic Dermatomyositis and Clinically Amyopathic Dermatomyositis

OBJECTIVE

Gottron papules and Gottron sign are characteristic and possibly pathognomonic cutaneous features of classic dermatomyositis and clinically amyopathic dermatomyositis (DM/CADM). However, the Gottron papules/Gottron sign with cutaneous ulceration (ulcerative Gottron papules/Gottron sign) are less common. We aimed to clarify the clinical characteristics of patients with DM/CADM who have ulcerative Gottron papules/Gottron sign.

METHODS

Clinical features, laboratory findings, and prognosis of patients with DM/CADM who had Gottron papules/Gottron sign with or without ulceration were analyzed and compared.

RESULTS

Occurrences of acute interstitial pneumonia/subacute interstitial pneumonia (AIP/SIP) were significantly higher in patients with ulcerative Gottron papules/Gottron sign (19/26) versus patients with Gottron papules/Gottron sign without ulceration (2/66, p < 0.001). We also observed that the white blood cell counts (mean ± SD 4.2 ± 1.6 vs 6.9 ± 2.9; p < 0.001) and creatine kinase (CK) levels (198.0 ± 377.7 vs 1364.0 ± 2477.0; p = 0.019) were significantly lower, whereas the positive rate of antimelanoma differentiation-associated gene 5 antibody (anti-MDA5; 88.5% vs 6.1%, p < 0.001) and serum ferritin levels (665.2 ± 433.5 vs 256.2 ± 279.0, p < 0.001) were significantly higher in the patients with ulcerative Gottron papules/Gottron sign. Moreover, the cumulative survival rate of the group with ulcerative Gottron papules/Gottron sign was significantly lower (p < 0.001).

CONCLUSION

Patients with DM/CADM who have ulcerative Gottron papules/Gottron sign, positive anti-MDA5 antibody, and significantly lower baseline CK level are at increased risk of interstitial lung disease, especially AIP/SIP. A new designation for this subgroup of patients should be established to draw more attention to this clinical entity.

Initial limited three-level thin-section computed tomography scorings predict the prognosis of acute/subacute interstitial pneumonia in patients with dermatomyositis

OBJECTIVES

We investigated the prediction of outcomes of patients with dermatomyositis with acute/subacute interstitial pneumonia (DM-A/SIP) on the basis of chest computed tomography (CT) images.

METHODS

In 20 patients with DM-A/SIP (13 survivors; seven deaths), the relationships between prognostic outcomes and chest high-resolution CT (HRCT) findings or limited three-level thin-section CT scoring on the first examination were retrospectively investigated.

RESULTS

No significant difference was noted in chest HRCT findings between the survivor group and death group. The ground-glass opacity (GGO) scores of the right upper and middle lobes and left upper lobe, and the fibrosis score of the right middle lobe were significantly higher in the death group than in the survivor group (p = 0.01, 0.001, 0.02, and 0.02, respectively). The influence of the GGO score of the right middle lobe on death from IP was the strongest among the items examined, and it was independently significant (p = 0.01). A right middle lobe GGO score of ≥3 (GGO ≥ 25% of the lobe) was determined to be the best cut-off value for a poor prognosis (sensitivity: 85.7%, specificity: 85.7%), and the survival rate after 24 weeks was significantly lower in patients with a right middle lobe GGO score of ≥3 (survival rate: 0.0%) than in those with a score of< 3 (92.9%) (p < 0.0001).

CONCLUSIONS

The prognosis of patients with DM-A/SIP was poor when the range of right middle lobe GGO was 25% or higher on limited three-level thin-section CT.

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.

Cutaneous paraneoplastic disorders in stomach cancer: Collaboration between oncologically active dermatologists and clinical oncologists

To our knowledge this is the first systemic review that provides an overview of the cutaneous paraneoplastic syndromes (CPS) (i.e., clinical manifestations, pathomechanisms, and treatment modalities) occurring in stomach cancer. CPS are caused by substances produced by stomach cancer and may precede, coincide with, or follow the diagnosis of this malignancy. More than 20 possible CPS in association with stomach cancer have been identified. CPS mostly compromises the patient's quality of life by skin impairment plus discomfort and are often associated with a dismal prognosis on survival. Studies of these CPS not only in stomach cancer have partially contributed to the understanding of pathomechanism and since CPS may be the presenting sign of an occult cancer, cognizance of their features and clinical implications are of considerable importance. Patients with these syndromes should have an appropriate work-up for a possibly occult malignancy with consecutive successful early treatment.

Increased Serum LIGHT Levels Correlate with Disease Progression and Severity of Interstitial Pneumonia in Patients with Dermatomyositis: A Case Control Study

BACKGROUND

Activated CD8+ T cells play an important role in the pathogenesis of dermatomyositis (DM) with interstitial pneumonia (IP). Serum CD8+ T-cell activator, LIGHT, and Th1/Th2/Th17 cytokines were measured in DM-IP patients and compared with clinical parameters to investigate their usefulness.

METHODS

The correlations between the clinical findings and serum LIGHT and Th1/Th2/Th17 cytokine levels were investigated in 21 patients with DM-IP (14 with rapidly progressive IP [RPIP] and 7 with chronic IP [CIP], including 4 fatal cases of IP).

RESULTS

The median serum LIGHT level was 119 (16-335.4) pg/ml, which was higher than that in healthy control subjects and DM patients without IP. The median serum IL-6 level was 14.7 (2.4-154.5) pg/ml (n = 13). The other cytokines were detected in only a few patients. The median serum LIGHT level in DM-RPIP patients (156 [49.6-335.4] pg/ml) was significantly higher than that in DM-CIP patients (94.3 [16-164.2] pg/ml) (P = 0.02). The serum IL-6 level did not correlate with either progression or outcome of DM-IP. ROC curve analysis determined a serum LIGHT level of ≥120 pg/ml to be the cut-off value for the rapid progression of DM-IP. Serum LIGHT levels correlated significantly with %DLco (R = 0.55, P = 0.04) and total ground-glass opacity scores (R = 0.72, P = 0.0002). The serum LIGHT level significantly decreased to 100.5 (12.4-259.3) pg/ml 4 weeks after treatment initiation (P = 0.04).

CONCLUSIONS

The serum LIGHT level may be a promising marker of disease progression and severity in patients with DM-IP.

An overview of polymyositis and dermatomyositis

Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, histopathology, response to treatment, and prognosis. Although their clinical pictures differ, they both present with symmetrical, proximal muscle weakness. Treatment relies mainly upon empirical use of corticosteroids and immunosuppressive agents. A deeper understanding of the molecular pathways that drive pathogenesis, careful phenotyping, and accurate disease classification will aid clinical research and development of more efficacious treatments. In this review we address the current knowledge of the epidemiology, clinical characteristics, diagnostic evaluation, classification, pathogenesis, treatment, and prognosis of polymyositis and dermatomyositis.

Cutaneous ulceration in dermatomyositis: association with anti-melanoma differentiation-associated gene 5 antibodies and interstitial lung disease

OBJECTIVE

To identify clinical and serologic correlates of cutaneous ulcers in dermatomyositis (DM).

METHODS

We retrospectively examined a cohort of 152 DM patients. We compared the features of patients with ulcers to those without ulcers using chi-square or Fisher's exact tests and used univariate and multivariate logistic regression models to assess the association between ulcers and clinical features such as malignancy, interstitial lung disease (ILD), and amyopathic disease.

RESULTS

Forty-three patients (28%) had cutaneous ulcers. Nearly half the patients had ulcers present in more than 1 location: 24 (56%) had ulcers over the extensor surfaces of joints, 18 (42%) at the digital pulp or periungual areas, and 25 (58%) had ulcers located elsewhere. In univariate analysis ulcers were associated with Asian race, but not with other clinical and demographic features, including malignancy or ILD. In multivariate analysis ulcers were significantly associated with anti-melanoma differentiation gene 5 (anti-MDA5) antibodies (odds ratio 10.14, 95% confidence interval 1.95-52.78; P = 0.0059) and this was greatest for ulcers located at the digital pulp. In patients with cutaneous ulcers, ILD risk was specifically increased only in patients with anti-MDA5-positive antibodies.

CONCLUSION

We confirmed the strong association between anti-MDA5 antibodies and cutaneous ulcers, with the novel finding that the association of cutaneous ulcers with ILD depends upon the presence of anti-MDA5 antibodies. DM patients who display this cutaneous phenotype should undergo appropriate evaluation for ILD.

Renal cell carcinoma and amyopathic dermatomyositis

Amyopathic dermatomyositis (dermatomyositis siné myositis) is a rare disorder with cutaneous lesions identical to those of classic dermatomyositis, but with no clinical evidence of myopathy. Association with malignancy has been suggested in a number of reports. We report the case of a 69-year-old man with a recent diagnosis of amyopathic dermatomyositis, who presented to the urology service with hematuria. Investigations revealed a 5.8-cm renal cell carcinoma and the patient underwent left radical nephrectomy without complication. To our knowledge, an association with renal cell carcinoma and amyopathic dermatomyositis has not been previously described.

The role of type I interferons and other cytokines in dermatomyositis

Much work has been done to unveil the mechanisms behind the pathogenesis of dermatomyositis (DM) - mainly those involving certain pathogenic cytokines, termed "pathokines" as the principal cytokines involved. Recently, it has become clear that a group of cytokines known as type I interferons (IFN-Is) play a significant role in the development of DM. We review the literature published between 1946 and 2014 using an Ovid Medline database search to provide an update on the role of IFN-Is and other cytokines in the pathogenesis of DM. We provide information about the genes and proteins induced by IFN-Is and potential mechanisms by which these downstream products relate to clinical disease activity. We also explore findings of other autoimmune phenomena that may contribute to disease onset and activity including T-helper 17 (Th17) cells and associated interleukins, as well as autoantibodies. Finally, we provide a brief update on current treatment options for DM as well as some new immunomodulatory treatment modalities in development.