Hydroxychloroquine levels in pregnancy and materno-fetal outcomes in Systemic Lupus Erythematosus patients.

OBJECTIVES: Data about hydroxychloroquine (HCQ) levels during pregnancy are sparse. We assessed HCQ whole blood levels at first trimester of pregnancy as a potential predictor of maternal and obstetric/fetal outcomes in patients with systemic lupus erythematosus (SLE). METHODS: We included pregnant SLE patients enrolled in the prospective GR2 study receiving HCQ, with at least one available first-trimester whole-blood HCQ assay. We evaluated several cut-offs for HCQ whole blood levels, including ≤200 ng/ml for severe non-adherence. Primary outcomes were maternal flares during the second and third trimesters of pregnancy, and adverse pregnancy outcomes (APOs: fetal/neonatal death, placental insufficiency with preterm delivery, and small-for-gestational-age neonates). RESULTS: We included 174 patients (median age: 32.1 years, IQR 28.8-35.2). Thirty (17.2%) patients had flares, 4 (2.3%) being severe. APOs occurred in 28 patients (16.1%). There were no significant differences in APOs by HCQ level for either those with subtherapeutic HCQ levels (≤500 ng/ml vs >500 ng/ml: 23.5% vs 14.3%, p = 0.19) or those with non-adherent HCQ levels (≤200 ng/ml vs >200 ng/ml: 20.0% vs 15.7%, p = 0.71). Similarly, the overall rate of maternal flares did not differ significantly by HCQ level cut-off, but patients with subtherapeutic (HCQ ≤500 ng/ml: 8.8% vs 0.7%, p = 0.02) and non-adherent HCQ levels (≤200 ng/ml: 13.3% vs 1.3%, p = 0.04) had significantly more severe flares. CONCLUSION: In this large prospective study of pregnant SLE patients, first-trimester subtherapeutic (≤500 ng/ml) and severe non-adherent (≤200 ng/ml) HCQ levels were associated with severe maternal flares, but not with APOs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02450396.

Determination of four homogeneous subgroups of patients with antiphospholipid syndrome: a cluster analysis based on 509 cases.

OBJECTIVE: APS is a heterogeneous disease with different phenotypes. Using an unsupervised hierarchical cluster analysis, we aimed to determine distinct homogeneous phenotypes among APS patients. METHODS: We performed an observational, retrospective study of APS patients enrolled in the French multicentre 'APS and SLE' registry who met the Sydney classification criteria. The clustering process involved an unsupervised multiple correspondence analysis followed by a hierarchical ascendant clustering analysis; it used 27 variables selected to cover a broad range of APS clinical and laboratory manifestations. RESULTS: These analyses included 509 patients, mainly women (77.8%). Mean (s.d.) age at APS diagnosis was 36.2 (14.6) years, and mean follow-up since diagnosis 10.3 (8.5) years. This hierarchical classification cluster analysis yielded four homogeneous groups of patients: cluster 1, mostly with venous thromboembolism without any associated autoimmune disease; cluster 2, older, lowest proportion of women, history of arterial events, and/or with migraines, arterial hypertension, diabetes mellitus, or dyslipidaemia; cluster 3, younger, highest proportion of women, associated SLE or other autoimmune diseases, and a history of venous thromboembolism or pregnancy morbidity; and cluster 4, mainly with a history of catastrophic antiphospholipid syndrome, aPL-associated nephropathy, and pregnancy morbidity, with frequent triple positivity and more deaths (16.7%). CONCLUSIONS: Our study applied an unsupervised clustering method to distinguish four homogeneous APS patient subgroups that were predominantly venous; arterial; associated with SLE or another autoimmune disease; and arterial microthrombotic. Heterogeneous pathophysiological mechanisms may explain these findings.

Functional brain connectivity changes across the human life span: From fetal development to old age.

The dynamic of the temporal correlations between brain areas, called functional connectivity (FC), undergoes complex transformations through the life span. In this review, we aim to provide an overview of these changes in the nonpathological brain from fetal life to advanced age. After a brief description of the main methods, we propose that FC development can be divided into four main phases: first, before birth, a strong change in FC leads to the emergence of functional proto-networks, involving mainly within network short-range connections. Then, during the first years of life, there is a strong widespread organization of networks which starts with segregation processes followed by a continuous increase in integration. Thereafter, from adolescence to early adulthood, a refinement of existing networks in the brain occurs, characterized by an increase in integrative processes until about 40 years. Middle age constitutes a pivotal period associated with an inversion of the functional brain trajectories with a decrease in segregation process in conjunction to a large-scale reorganization of between network connections. Studies suggest that these processes are in line with the development of cognitive and sensory functions throughout life as well as their deterioration. During aging, results support the notion of dedifferentiation processes, which refer to the decrease in functional selectivity of the brain regions, resulting in more diffuse and less specialized FC, associated with the disruption of cognitive functions with age. The inversion of developmental processes during aging is in accordance with the developmental models of neuroanatomy for which the latest matured regions are the first to deteriorate.

Rituximab plus belimumab in non-infectious refractory cryoglobulinemia vasculitis: A pilot study.

OBJECTIVE: To report the efficacy of rituximab plus belimumab in patients with refractory cryoglobulinemia vasculitis (CV). METHODS: Belimumab was administered intravenously at a dose of 10 mg/kg on days 0, 14, 28 and then every month in association with rituximab in 4 patients with refractory CV. Demographic, clinical and laboratory characteristics, treatment modalities and outcomes were recorded. RESULTS: All patients had type II IgM Kappa cryoglobulinemia, which was associated with primary Sjögren syndrome (n = 1), hepatitis C virus infection (n = 1), and essential (n = 2). Main manifestations of CV included purpura (n = 4), arthralgia and peripheral neuropathy (n = 3), and glomerulonephritis and skin ulcers (n = 1). In all cases, CV was refractory and/or relapse following rituximab. Intravenous belimumab infusion along with rituximab resulted in rapid clinical response in the four patients. Osteitis and recurrent urinary tract infections occurred in two patients. CONCLUSION: Belimumab along with rituximab showed promising results in refractory patients with CV.

Risk factors for hydroxychloroquine retinopathy in systemic lupus erythematosus: a case-control study with hydroxychloroquine blood-level analysis.

OBJECTIVE: HCQ is an essential medication in SLE, proven to lengthen survival and reduce flares. Its use, however, is limited by its rare but severe ophthalmological complications. Here, we aimed to analyse factors associated with HCQ retinopathy including HCQ blood levels. METHODS: This case-control study compared SLE patients with and without HCQ retinopathy, defined by abnormal results for at least two of the following ophthalmological tests: automated visual fields, spectral-domain optical coherence tomography (SD-OCT), multifocal electroretinogram (mfERG) and fundus autofluorescence. We compared clinical and laboratory findings to assess risk factors for HCQ retinopathy. RESULTS: The study included 23 patients with confirmed retinopathy (cases) and 547 controls. In the univariate analysis, age (P < 0.001), height (P = 0.045), creatinine clearance (P < 0.001), haemoglobin concentration (P = 0.01), duration of HCQ intake, (P < 0.001), higher cumulative HCQ dose (P < 0.001) and geographical origin (West Indies and sub-Saharan Africa) (P = 0.007) were associated with the risk of retinopathy, while HCQ blood levels were not. In the multivariate analysis, only cumulative dose (P = 0.016), duration of intake (P = 0.039), creatinine clearance (P = 0.002) and geographical origin (P < 0.0001, odds ratio 8.7) remained significantly associated with retinopathy. CONCLUSION: SLE patients on HCQ should be closely monitored for retinopathy, especially those from the West Indies or sub-Saharan Africa, or with renal insufficiency, longer HCQ intake or a high cumulative dose. Although reducing the daily dose of HCQ in patients with persistently high HCQ blood levels seems logical, these concentrations were not associated with retinopathy in this study with controls adherent to treatment.

Efficacy and safety of biologics in relapsing polychondritis: a French national multicentre study.

OBJECTIVES: To assess the efficacy and the safety of biologics in a cohort of patients with relapsing polychondritis (RP). METHODS: We conducted a French multicentre retrospective cohort study including patients treated with biologics for RP. Efficacy outcomes were clinical response (partial or complete) and complete response during the first 6 months of exposure, plus daily corticosteroid dose at 6 months. Other outcomes were adverse drug reactions (ADRs), persistence of biologics and factors associated with a response. RESULTS: This study included 41 patients exposed to 105 biologics (tumour-necrosis factor (TNF) inhibitors, n=60; tocilizumab, n=17; anakinra, n=15; rituximab, n=7; abatacept, n=6). Overall response rate during the first 6 months of exposure was 62.9%. Complete response rate was 19.0%. Reduced corticosteroid doses were highly variable among patients. ADRs were mostly infections (n=42). Reasons for biologic withdrawal (73.3%) were insufficient efficacy (34.3%; ranging from 23.5% for tocilizumab to 72.7% for etanercept), loss of efficacy (18.1%) and ADRs (20.9%; mostly for anakinra: 46.7%). Persistence was comparable among biologic classes. Among TNF inhibitors, the highest persistence was observed with adalimumab. Differences in clinical response rates were observed depending on biologics and organ involvement. There were trends towards a lower response rate in cases with associated myelodysplastic syndrome and for a higher response rate for nasal/auricular chondritis, sternal chondritis and concomitant exposure to non-biologic disease-modifying antirheumatic drugs. CONCLUSIONS: This study describes the efficacy of biologics for refractory RP. However, the number of complete responses was low and there were concerns about the risk of ADRs, particularly infections.

Dermatomyositis With or Without Anti-Melanoma Differentiation-Associated Gene 5 Antibodies: Common Interferon Signature but Distinct NOS2 Expression.

The anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody is specifically associated with dermatomyositis (DM). Nevertheless, anti-MDA5(+)-patients experience characteristic symptoms distinct from classic DM, including severe signs of extramuscular involvement; however, the clinical signs of myopathy are mild or even absent. The morphological and immunological features are not yet described in adulthood. Data concerning the pathophysiology of anti-MDA5 DM are sparse; however, the importance of the interferon (IFN) type I pathway involved in DM has been shown. Our aim was to define morphological alterations of the skeletal muscle and the intrinsic immune response of anti-MDA5-positive DM patients. Immunohistological and RT-PCR analysis of muscle biopsy specimens from anti-MDA5 and classic DM were compared. Those with anti-MDA5 DM did not present the classic features of perifascicular fiber atrophy and major histocompatibility complex class I expression. They did not show significant signs of capillary loss; tubuloreticular formations were observed less frequently. Inflammation was focal, clustering around single vessels but significantly less intense. Expression of IFN-stimulated genes was up-regulated in anti-MDA5 DM; however, the IFN score was significantly lower. Characteristic features were observed in anti-MDA5 DM and not in classic DM patients. Only anti-MDA5 DM showed numerous nitric oxide synthase 2-positive muscle fibers with sarcoplasmic colocalization of markers of regeneration and cell stress. Anti-MDA5-positive patients demonstrate a morphological pattern distinct from classic DM.

Spontaneous remission of fully symptomatic visceral leishmaniasis.

BACKGROUND: Visceral leishmaniasis (VL), i.e., infection with Leishmania sp. associated with high fever, weight loss, massive splenomegaly and markedly altered laboratory parameters, is generally fatal if untreated. The possibility of transient spontaneous remission of fully symptomatic visceral leishmaniasis (VL) has been mentioned but, to our knowledge) has never been documented. CASE PRESENTATION: We report the first documented history of a patient with overt, confirmed VL experiencing a complete remission in the absence of any anti-leishmanial therapy. The diagnosis of VL at the time of the self-resolving episode was strongly suspected based on clinical presentation and presence of antileishmanial antibody, then unequivocally confirmed years later by the presence of an amastigote on a stored smear and the positive quantitative PCR with Leishmania-specific primers from the material scraped from this same slide CONCLUSION: This report demonstrates that complete spontaneous remission may occur in patients with overt, fully symptomatic VL. VL should therefore be considered in cases of self-resolving or relapsing episodes of fever of unknown origin. Confirmation should be based on both serological tests and specific PCR on a blood sample.

Manual segmentation of individual muscles of the quadriceps femoris using MRI: a reappraisal.

PURPOSE: To propose a manual segmentation method for individual quadriceps femoris (QF) muscles and to test its reliability for muscle volume estimation. MATERIALS AND METHODS: Images were acquired every 5 mm along the thigh using a 3T MRI scanner on 10 young (mean age: 25 years) and 10 older (mean age: 75 years) adults using a three-point 3D Dixon sequence. In each slice, anatomical cross-sectional areas of the individual quadriceps muscles of the dominant leg were outlined by two operators working independently. Differences between operators were assessed by means of Bland-Altman plots and intraclass correlation coefficients (ICC). This study was approved by the local Ethics Committee. RESULTS: Precise delimitation of individual muscles along the femur often remains challenging, particularly near their insertion areas where some muscles may be partially or totally fused. There was, however, an excellent interoperator segmentation reliability despite a systematic significant difference between operators (ICC > 0.99), mainly due to delineation divergences. Considering all subjects and muscles, differences between operators were all lower than 4.4%. CONCLUSION: This work has demonstrated the excellent reliability of manual segmentation to assess cross-sectional areas and therefore the volume of individual QF muscles using MRI. It may serve as a basis for a future segmentation consensus of the QF muscles.

Hydroxychloroquine in systemic lupus erythematosus: results of a French multicentre controlled trial (PLUS Study).

INTRODUCTION: Hydroxychloroquine (HCQ) is an important medication for treating systemic lupus erythematosus (SLE). Its blood concentration ([HCQ]) varies widely between patients and is a marker and predictor of SLE flares. This prospective randomised, double-blind, placebo-controlled, multicentre study sought to compare standard and adjusted HCQ dosing schedules that target [HCQ] ≥1000 ng/ml to reduce SLE flares. PATIENTS AND METHODS: [HCQ] was measured in 573 patients with SLE (stable disease and SELENA-SLEDAI≤12) treated with HCQ for at least 6 months. Patients with [HCQ] from 100 to 750 ng/ml were randomised to one of two treatment groups: no daily dose change (group 1) or increased HCQ dose to achieve the target [HCQ] (group 2). The primary end point was the number of patients with flares during 7 months of follow-up. RESULTS: Overall, mean [HCQ] was 918±451 ng/ml. Active SLE was less prevalent in patients with higher [HCQ]. A total of 171 patients were randomised and followed for 7 months. SLE flare rates were similar in the two groups (25% in group 1 vs 27.6% in group 2; p=0.7), but a significant spontaneous increase in [HCQ] in both groups between inclusion and randomisation strongly suggested improved treatment adherence. Patients at the therapeutic target throughout follow-up tended to have fewer flares than those with low [HCQ] (20.5% vs 35.1%, p=0.12). CONCLUSIONS: Although low [HCQ] is associated with higher SLE activity, adapting the HCQ dose did not reduce SLE flares over a 7-month follow-up.

Factors associated with adverse events resulting from medical errors in the emergency department: two work better than one.

BACKGROUND: The Emergency Department (ED) is an environment at risk for medical errors. OBJECTIVE: Our aim was to determine the factors associated with the adverse events resulting from medical errors in the ED among patients who were admitted. METHODS: This was a prospective observational study. For a 1-month period, we included all ED patients who were subsequently admitted to the medical ward. Detection of medical errors was made by the admitting physician and then validated by two experts who reviewed all available data and medical charts pertaining to the patient's hospital stay, including the first review from the ward physician. Related adverse events resulting from medical errors were then classified by type and severity. Adverse events were defined as medical errors that needed an intervention or caused harm to the patient. Univariate analysis examined relationships between characteristics of both patients and physicians and the risk of adverse events. RESULTS: From 197 analyzed patients, 130 errors were detected, of these, 34 were categorized as adverse events among 19 patients (10%). Seventy-six percent of these were categorized as proficiency errors. The only factors associated with a lower risk of adverse events were the transition of care involving a handoff within the ED (0% vs. 19%; p = 0.03) and the involvement of a resident (junior doctor) in addition to the senior physician (37% vs. 67%; p < 0.01). CONCLUSIONS: In our study, the involvement of more than one physician was associated with a lower risk of adverse events.

Precipitating factors of catastrophic antiphospholipid syndrome: the role of anticoagulant treatment in a series of 112 patients.

BACKGROUND: The prevention of catastrophic antiphospholipid syndrome (CAPS), a rare complication of antiphospholipid syndrome (APS), is a major goal. OBJECTIVES: We analyzed its precipitating factors, focusing on anticoagulation immediately before CAPS episodes. METHODS: We retrospectively analyzed patients in the French multicenter APS/systemic lupus erythematosus database with at least 1 CAPS episode. Then we compared each patient with known APS before CAPS with 2 patients with non-CAPS APS matched for age, sex, center, and APS phenotype. RESULTS: We included 112 patients with CAPS (70% women; mean age, 43 ± 15 years). At least 1 standard precipitating factor of CAPS was observed for 67 patients (64%), which were mainly infections (n = 28, 27%), pregnancy (n = 23, 22%), and surgery (n = 16, 15%). Before the CAPS episode, 67 (60%) patients already had a diagnosis of APS. Of the 61 treated with anticoagulants, 32 (48%) received vitamin K antagonists (VKAs), 23 (34%) heparin, and 2 (3%) a direct oral anticoagulant. They were less likely than their matched patients with APS without CAPS to receive VKA (48% vs 66%, p = .001). Among those treated with VKA, 72% had a subtherapeutic international normalized ratio (ie, <2) versus 28% in patients with APS without CAPS (p < .001). Finally, excluding pregnant patients (n = 14) for whom we could not differentiate the effect of treatment from that of pregnancy, we were left with 47 cases, 32 (68%) of whom had recently begun a direct oral anticoagulant, planned bridging therapy, or had VKA treatment with international normalized ratio <2. CONCLUSION: These results strongly suggest that suboptimal anticoagulation management can trigger CAPS in patients with thrombotic APS.

Cutaneous Involvement in Catastrophic Antiphospholipid Syndrome in a Multicenter Cohort of 65 Patients.

Importance: Catastrophic antiphospholipid syndrome (CAPS) is a severe, rare complication of antiphospholipid syndrome (APS), but cutaneous involvement has not yet been adequately described. Objective: To describe cutaneous involvement during CAPS, its clinical and pathological features, and outcomes. Design, Setting, and Participants: This cohort study was a retrospective analysis of patients included in the French multicenter APS/systemic lupus erythematosus register (ClinicalTrials.gov: NCT02782039) by December 2020. All patients meeting the revised international classification criteria for CAPS were included, and patients with cutaneous manifestations were analyzed more specifically. Main Outcomes and Measures: Clinical and pathological data as well as course and outcome in patients with cutaneous involvement during CAPS were collected and compared with those in the register without cutaneous involvement. Results: Among 120 patients with at least 1 CAPS episode, the 65 (54%) with skin involvement (43 [66%] women; median [range] age, 31 [12-69] years) were analyzed. Catastrophic antiphospholipid syndrome was the first APS manifestation for 21 of 60 (35%) patients with available data. The main lesions were recent-onset or newly worsened livedo racemosa (n = 29, 45%), necrotic and/or ulcerated lesions (n = 27, 42%), subungual splinter hemorrhages (n = 19, 29%), apparent distal inflammatory edema (reddened and warm hands, feet, or face) (n = 15, 23%), and/or vascular purpura (n = 9, 14%). Sixteen biopsies performed during CAPS episodes were reviewed and showed microthrombi of dermal capillaries in 15 patients (94%). These lesions healed without sequelae in slightly more than 90% (58 of 64) of patients. Patients with cutaneous involvement showed a trend toward more frequent histologically proven CAPS (37% vs 24%, P = .16) than those without such involvement, while mortality did not differ significantly between the groups (respectively, 5% vs 9%, P = .47). Conclusions and Relevance: In this cohort study, half the patients with CAPS showed cutaneous involvement, with a wide spectrum of clinical presentations, including distal inflammatory edema. Skin biopsies confirmed the diagnosis in all but 1 biopsied patient.

Long-term outcome of 32 patients with chorea and systemic lupus erythematosus or antiphospholipid antibodies.

OBJECTIVE: The aim of this work was to describe chorea during systemic lupus erythematosus or antiphospholipid antibodies and its long-term outcome. METHODS: We retrospectively analyzed clinical features, laboratory findings, imaging characteristics, and outcome in a series of 32 patients. RESULTS: Most patients were women (28 of 32), and mean age at onset of chorea was 20.6 (9-62) years. Chorea was inaugural for 28 patients. Improvement was observed with various treatments. During follow-up (12.2 ± 11.3 years), severe manifestations of systemic lupus erythematosus were rare. Antiphospholipid antibodies were repeatedly positive for 90% of the patients. Twelve patients developed arterial thrombosis. Prophylactic treatment with antithrombotic therapy might reduce the risk of further thrombosis (8% versus 57%; P = 0.01). Cardiac valvulopathy occurred in 22 patients during follow-up. Chorea relapsed in 8 cases. CONCLUSIONS: Chorea had a good outcome in itself. This long-term follow-up shows, for the first time, that these patients have substantial risk for further arterial thrombosis.

Functional magnetic resonance imaging study of Piaget's conservation-of-number task in preschool and school-age children: a neo-Piagetian approach.

Jean Piaget's theory is a central reference point in the study of logico-mathematical development in children. One of the most famous Piagetian tasks is number conservation. Failures and successes in this task reveal two fundamental stages in children's thinking and judgment, shifting at approximately 7 years of age from visuospatial intuition to number conservation. In the current study, preschool children (nonconservers, 5-6 years of age) and school-age children (conservers, 9-10 years of age) were presented with Piaget's conservation-of-number task and monitored by functional magnetic resonance imaging (fMRI). The cognitive change allowing children to access conservation was shown to be related to the neural contribution of a bilateral parietofrontal network involved in numerical and executive functions. These fMRI results highlight how the behavioral and cognitive stages Piaget formulated during the 20th century manifest in the brain with age.

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence.

BACKGROUND: Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients. METHODS: HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score > 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ < 200 ng/mL. RESULTS: The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels (P = 0.023), but not serum HCQ levels, were independently associated with active SLE. From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76-0.94) and specificity of 0.89 (95% CI 0.72-0.98). All serum HCQ levels of patients with whole-blood HCQ below the detectable level (< 20 ng/mL) were also undetectable (< 20 ng/mL). CONCLUSIONS: These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable.

Different phenotypes in dermatomyositis associated with anti-MDA5 antibody: Study of 121 cases.

OBJECTIVES: The predominance of extramuscular manifestations (e.g., skin rash, arthralgia, interstitial lung disease [ILD]) as well as the low frequency of muscle signs in anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5+) dermatomyositis caused us to question the term myositis-specific antibody for the anti-MDA5 antibody, as well as the homogeneity of the disease. METHODS: To characterize the anti-MDA5+ phenotype, an unsupervised analysis was performed on anti-MDA5+ patients (n = 83/121) and compared to a group of patients with myositis without anti-MDA5 antibody (anti-MDA5-; n = 190/201) based on selected variables, collected retrospectively, without any missing data. RESULTS: Within anti-MDA5+ patients (n = 83), 3 subgroups were identified. One group (18.1%) corresponded to patients with a rapidly progressive ILD (93.3%; p < 0.0001 across all) and a very high mortality rate. The second subgroup (55.4%) corresponded to patients with pure dermato-rheumatologic symptoms (arthralgia; 82.6%; p < 0.01) and a good prognosis. The third corresponded to patients, mainly male (72.7%; p < 0.0001), with severe skin vasculopathy, frequent signs of myositis (proximal weakness: 68.2%; p < 0.0001), and an intermediate prognosis. Raynaud phenomenon, arthralgia/arthritis, and sex permit the cluster appurtenance (83.3% correct estimation). Nevertheless, an unsupervised analysis confirmed that anti-MDA5 antibody delineates an independent group of patients (e.g., dermatomyositis skin rash, skin ulcers, calcinosis, mechanic's hands, ILD, arthralgia/arthritis, and high mortality rate) distinct from anti-MDA5- patients with myositis. CONCLUSION: Anti-MDA5+ patients have a systemic syndrome distinct from other patients with myositis. Three subgroups with different prognosis exist.