[New classifications and pathophysiology of the inflammatory myopathies]

Polymyositis/dermatomyositis readmissions: analysis of the nationwide readmission database

BACKGROUND

There is a scarcity of national population-based studies on polymyositis (PM)/dermatomyositis (DM) readmissions in the USA. In this study, we aim to describe the rates, reasons for readmissions, and characteristics of readmissions for adults hospitalized for PM/DM in the USA.

METHODS

We analyzed the 2018 Nationwide Readmissions Database (NRD). We included index hospitalizations for all adult DM/PM patients with a principal diagnosis of PM/DM using ICD-10 codes. We excluded elective and traumatic readmissions. Using a "rank" command in STATA, the most common specific principal diagnosis of readmissions was outlined. Chi-square tests were used to compare baseline characteristics between readmissions and index hospitalizations. STATA 16 was used for analysis.

RESULTS

A total of 1610, 1286, and 842 index hospitalizations with a principal diagnosis of PM/DM, that were discharged alive, were included in the 30-, 90-, and 180-day readmission analysis, respectively. Among these, 193 (12%), 276 (21.5%), and 240 (28.5%) were readmitted within 30, 90, and 180 days, respectively. PM and sepsis were the most common reasons for reasons across the 3 timeframes. 30-day readmissions were responsible for an aggregate of 4.1 million US dollars in total hospital cost and 1518 hospital days in 2018. Compared to index hospitalizations, 30-day readmissions have higher Charlson Comorbidity Index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.

CONCLUSION

About a third of PM/DM hospitalized patients are readmitted within 180 days. Readmissions constitute a significant economic burden to the health care system. PM and sepsis are the main reasons for readmissions. Key points • About a third of polymyositis (PM)/dermatomyositis (DM) hospitalized patients are readmitted within 180 days • PM and sepsis are the main reasons for readmissions. • Readmissions of PM/DM Patients constitute a significant economic burden to the health care system. • Compared to index hospitalizations, 30-day readmissions have higher Charlson comorbidity index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.

Mass cytometry reveals an impairment of B cell homeostasis in anti-synthetase syndrome

Recent data suggest the implication of T, B and NK cells in the anti-synthetase syndrome (ASyS); nevertheless their role and activation states are poorly described. We performed deep immune-profiling using 37 markers on peripheral blood cells from 10 ASyS patients versus 17 healthy donors (HD) and 26 myositis control patients. We show decreased percentages of memory B cells in ASyS patients (mean ± SEM: ASyS = 13 ± 3%, HD = 37 ± 4% and 'myositis controls' = 32 ± 3), counterbalanced by increased percentages of naïve B cells. Interestingly, perifascicular infiltrations of memory B cells within muscle biopsies of ASyS patients suggest that they niche within the muscle.

[Retrospective analysis of anti-TIF1gamma, anti-NXP2 and anti-SAE1/2 antibodies carriers at Bordeaux university hospital from November 2014 to February 2017]

INTRODUCTION

Dermatomyositis are rare autoimmune diseases. The discovery of specific antibodies such as the anti-TIF1γ, anti-SAE1/2 and anti-NXP2 antibodies has been associated with specific clinical phenotypes. The recent development of standardized kits based on immunodot method is a progress in dermatomyositis diagnosis. Here, we report the clinical characteristics of patients carrying these antibodies with or without clinical setting of dermatomyositis.

METHODS

This single-center french retrospective study was conducted from November 2014 to February 2017 at Bordeaux university hospital. Patients carrying anti-TIF1γ, anti-SAE1/2 and anti-NXP2 antibodies, detected by immunodot, were included.

RESULTS

Among the 58 patients included, only 10 were finally diagnosed with dermatomyositis. Some form of cancer was found in all anti-TIF1γ antibodies positive patients associated with dermatomyositis. Among the 48 anti-TIF1γ, anti-SAE1/2 and anti-NXP2 antibodies positive patients without clinical phenotype of dermatomyositis, 30 had autoimmune or inflammatory condition and 39 patients presented a significant biological autoimmunity. None of them developed dermatomyositis during the follow-up.

CONCLUSION

The immunodot kit allowed the diagnosis of 10 dermatomyositis. A high number of autoantibody positive patients without dermatomyositis raises the issue of the immunodot's performances in the context of biological autoimmunity.

Pulmonary arterial hypertension in idiopathic inflammatory myopathies: Data from the French pulmonary hypertension registry and review of the literature

Occurrence of pulmonary arterial hypertension (PAH) in idiopathic inflammatory myopathies (IIMs) without extensive interstitial lung disease (ILD) has rarely been described in the medical literature. This study aimed to report all cases with association of PAH and IIM in the French Pulmonary Hypertension (PH) Registry, to identify IIM features associated with the presence of PAH, and to describe treatment modalities of these patients.All cases of IIM-PAH were retrieved from the French PH Registry, which gathers PH patients prospectively enrolled by 27 referral hospital centers across France. Patients were excluded if they had an extensive ILD or overlap syndrome. Characteristics of IIM-PAH patients were compared with a control group of IIM patients without PH.Among the 5223 PH patients in the Registry, 34 had a diagnosis of IIM. Among them, 3 IIM-PAH patients (2 females and 1 male) had no evidence of extensive ILD or overlap syndrome, and were included in this study. In these 3 patients, dermatomyositis (DM) was the only identified IIM. One patient had autoantibodies classically associated with IIM (anti-Ku). PAH had always developed after IIM onset, was severe in all cases, and led to a marked functional impairment.By pooling our cases with 6 patients previously reported in the literature, and comparing them with a control cohort of 35 IIM patients without PH, we identify several IIM characteristics possibly associated with PAH occurrence, including DM subtype (78% vs 46%; P = 0.02), skin involvement (P = 0.04), anti-SSA antibodies (P = 0.05), and peripheral microangiopathy (P = 0.06).Overall, IIM-PAH patients were managed by corticosteroids and/or immunosuppressants, either alone or combined with PAH therapy. Patients did not seem to respond to IIM treatment alone.Our study reports for the first time the rare but possible association of PAH and IIM in a large prospective PH Registry. In that setting, PAH seems associated with DM, skin involvement, peripheral microangiopathy, and anti-SSA positivity. The best therapeutic strategy for IIM-PAH remains to be defined.

The spectrum of renal involvement in patients with inflammatory myopathies

Data regarding the incidence and outcome of renal involvement in patients with inflammatory myopathies (IM) remain scarce. We assessed the incidence and causes of acute kidney injury (AKI) and chronic kidney disease (CKD) in 150 patients with dermatomyositis, polymyositis, and antisynthetase syndrome followed in 3 French referral centers. Renal involvement occurred in 35 (23.3%) patients: AKI in 16 (10.7%), and CKD in 31 (20.7%) patients. The main cause of AKI was drug or myoglobinuria-induced acute tubular necrosis. Male sex, cardiovascular risk factors, cardiac involvement, and initial proteinuria >0.3 g/d were associated with the occurrence of AKI. The outcome of patients with AKI was poor: 13 (81%) progressed to CKD and 2 (12.5%) reached end-stage renal disease. In multivariate survival analysis, age at IM onset, male sex, a history of cardiovascular events, and a previous episode of AKI were associated with the risk of CKD. We also identified 14 IM patients who underwent a kidney biopsy in 10 nephrology centers. Renal pathology disclosed a wide range of renal disorders, mainly immune-complex glomerulonephritis. We identified in 5 patients a peculiar pattern of severe acute renal vascular damage consisting mainly of edematous thickening of the intima of arterioles. We found that AKI and CKD are frequent in patients with IM. Prevention of AKI is crucial in these patients, as AKI is a major contributor to their relatively high risk of CKD. A peculiar pattern of acute vascular damage is part of the spectrum of renal diseases associated with IM.

[Inclusion-body myositis]

Sporadic inclusion-body myositis (sIBM) presents in average at the sixth decade of life and affects three men for one woman. It is a non-lethal, slowly progressive but disabling disease. Except the striated muscles, no other organs (such as the interstitial lung) are involved. The phenotype of this myopathy is particular since it involves the axial muscles (camptocormia, swallowing dysfunction) and limb girdle (notably the quadriceps) but also the distal muscles (in particular the fingers' and wrists' flexors) in a bilateral but non-symmetrical manner. The clinical presentation is then very suggestive of the diagnosis, which remains to be proven by a muscle biopsy. Histological features defining the diagnosis associate endomysial inflammatory infiltrates with frequent invaded fibres (the myositis) and amyloid deposits generally accompanying rimmed vacuoles (the inclusions). There is still today a debate to know if this disease is at its beginning a degenerative or an auto-immune condition. Nonetheless, usual immunosuppressive drugs (corticosteroids, azathioprine, methotrexate) or polyvalent immunoglobulines remain ineffective and even may worsen the handicap. Some controlled randomized trials will soon be launched for this condition, but for now, the best therapeutic approach to slow down the rapidity of progression of the disease is to maintain muscle exercise with the help of the physiotherapists.

Actuality of juvenile dermatomyositis

Juvenile dermatomyositis is a rare disorder, but remains the most commonly occurring chronic inflammatory myopathy among children. Other than the proximal muscles and skin, which are routinely affected, vasculopathy may affect other viscera and can be multisystemic. A redefinition of the diagnostic criteria is currently underway and is likely to lead to other clinical signs and to sensitive and non-invasive examinations such as MRI. The impact of juvenile dermatomyositis on health and quality of life remains significant despite systemic corticosteroid therapy and immunosuppressor treatment, which have considerably improved the prognosis. Numerous predictors for favourable and pejorative evolution have been identified. The standardisation and the generalisation of clinical assessment tools will make it possible to carry out the clinical trials required to determine the relevance of the new therapeutic options available for children.

[Association myositis and hepatocellular carcinoma: one case and review of literature]

Association inflammatory myopathies and tumors are not fortuitous but association with hepatocellular carcinoma is rarely reported in literature. We described a case of association polymyositis hepatocellular carcinoma in 37-year-old black African patient, with fatal issue.

Antisynthetases syndrome associated with right heart failure

Cardiac involvement is a complication of end stage polymyositis with left heart insufficiency reported to be the most frequent manifestation. We here describe an unusual clinical presentation of antisynthetases syndrome, beginning with right-sided cardiomyopathy associated with right heart failure. A 26 year-old Caucasian male experienced a 6-month clinical course of polyarthritis, fever, sweats, and myalgia. Laboratory studies showed elevated C reactive protein, elevated sedimentation rate, and myolysis associated with anti SSA and anti JO1 antibodies. Electromyography showed a myopathic pattern. Muscle biopsy confirmed the diagnosis of polymyositis. Chest X ray, chest scan, and cardiac echography were normal. One week after hospital admission, the patient developed acute right heart insufficiency, and magnetic resonance imaging showed a right ventricular myocarditis with myocardial inflammatory thickening. Treatment with corticosteroids rapidly improved both symptoms and biological abnormalities.

[Dermatomyositis]

Dermatomyositis (DM) is a systemic inflammatory disease involving skin, muscles and other organs. Immunologically mediated inflammation of small vessels leads to vascular damage, especially of the muscular tissue. Typically DM presents clinically with DM-type local or generalized rash and proximal muscular weakness. Laboratory signs of muscular damage (elevated serum CK, myoglobinuria) may be initially absent. Magnetic resonance tomography frequently shows edema of the involved muscles, while electromyography shows a myopathic pattern with spontaneous activity. Muscle biopsy from involved muscle with histological, immunohistological, histochemical and possibly electron-microscopic examination confirms the diagnosis of inflammatory muscle disease and furthermore of DM-specific muscular findings. Typical findings include the deposition of 5b-9 complement components (membrane attack complex) at the capillaries, perifascicular inflammatory infiltrates composed predominantly of CD4+ T-lymphocytes, B-lymphocytes and plasmacytoid dendritic cells, endothelial swelling and damage, loss of capillaries with perifascicular atrophy and tubuloreticular endothelial inclusions on electron-microscopic examination. Detection of myositis-specific autoantibodies is especially helpful in the diagnosis of early and atypical cases with features of overlapping disease.

[Polymyositis and dermatomyositis in adults. Tunisian multicentre study]

INTRODUCTION

To study the clinical features and the outcome of polymyositis (PM) and dermatomyositis (DM) in Tunisia.

METHODS

Retrospective multicentre study conducted by the Tunisian Society of Internal Medicine. Adult patients with confirmed and probable PM and DM, according to the Bohan and Peter's criteria, were included in the study and followed-up between 1987 and 2005.

RESULTS

Twenty cases of PM and 50 cases of DM were included. Female/male sex-ratio was 2.5. The mean age at diagnosis was 40.7 years. Muscle weakness concerned girdle muscles in 94.3% and pharyngeal muscles in 42.8% of the patients. Interstitial lung disease and heart involvement occurred respectively in 35.7 and 20%. Eyelid erythema, peri-ungual erythema and Gottron's sign occurred in respectively 86, 50 and 36% of the cases of DM. Malignant disease was found in 12.8% of the patients (mainly gynecological and nasopharyngeal cancers). All patients received high dose corticosteroids with additional immunosuppressive drugs in 40% of the cases. The outcome was stabilization or partial improvement in 71.5% of the cases. Death occurred in 20% and was caused by respiratory failure, sepsis and cardiac failure.

CONCLUSION

The particularities of PM and DM in Tunisia are the preponderance of DM, early onset of the disease and high frequency of the nasopharyngeal cancer.