[Polymyositis and dermatomyositis in adults. Tunisian multicentre study]

Paraneoplastic Dermatomyositis Revealing the Metastatic Progression of an Undifferentiated Nasopharyngeal Carcinoma: A Case Report From Northern Morocco

Dermatomyositis (DM) is an inflammatory disease of striated muscles and skin that can occur sporadically or rarely be associated with malignancy, thereby serving as a potential clinical indicator or harbinger of underlying cancer. Knowing the pathognomonic, clinical, and biological features of DM plays a pivotal role in its recognition. Its correlation with nasopharyngeal carcinoma (NPC) is particularly prevalent in regions where the incidence of NPC is notably high, underscoring the intricate interplay between immune dysregulation and oncogenesis. Specially, in the context of patients previously treated for NPC, the emergence of DM raises the clinical suspicion of metastatic progression or recurrence of the cancer. Thus, early recognition of DM-associated paraneoplastic syndromes can facilitate prompt intervention and optimize patient outcomes. We present a case of metastatic progression in a patient treated for NPC, revealed by the pathognomonic, clinical, and biological signs of DM.

Epidemiology of Idiopathic Inflammatory Myopathies in Africa: A Contemporary Systematic Review

BACKGROUND

The epidemiology of idiopathic inflammatory myopathies (IIMs) has been extensively studied in America, Europe, and Asia, but remains unclear in Africa.

OBJECTIVE

The aim of this review was to summarize available data on the epidemiology of IIMs in Africa.

METHODS

We searched MEDLINE, EMBASE, and African Journals Online for studies published up to December 30, 2020, and reporting epidemiological data on IIMs in Africa. Data were combined through narrative synthesis. The review protocol was registered with PROSPERO, CRD42020186781.

RESULTS

We included 39 studies reporting 683 cases (71.7% adults) of IIMs. Incidence rates of ~7.5/1,000,000 person-years and 1.2/1,000,000 person-years were estimated for dermatomyositis (DM), whereas polymyositis (PM) had an incidence rate of 8.8/1,000,000 person-years. Prevalence estimates of 11.49/100,000 and 11/100,000 (95% confidence interval, 0-32) were provided for IIMs and the PM subtype, respectively. Mean age at diagnosis ranged from 7.9 to 57.2 years, and 50% to 100% of the patients were females. Main subtypes of adult-onset IIMs were DM (21%-93%) and PM (12%-79%), whereas the commonest juvenile subtype was juvenile DM (5.8%-9%). Skeletal muscle involvement (56%-100%) was the main disease feature, and esophagus was the most commonly affected internal organ (6%-65.2%). Anti-Jo1/histidyl tRNA synthetase (7%-100%) and anti-Mi2 (17%-45%) antibodies were the most frequent myositis specific antibodies. Early mortality was high (7.8%-45%), and main death causes were infections, cancers and organ damage in respiratory and cardiovascular domains.

CONCLUSIONS

Apart from a potential younger age at onset of adult IIMs in Africa, current sparse data mostly suggest a similar epidemiology between Africa and other regions. Further high-quality studies are required to validate these findings.

[Epidemiological profile of dermatomyositis and polymyositis: a study conducted in the Department of Rheumatology in Marrakech]

La dermatomyosite (DM) et la polymyosite (PM) sont des affections rares mais graves. Le but de ce travail est d'étudier, à travers la revue d'une série hospitalière, leur profil épidémiologique, clinique et évolutif. Il s´agit d´une étude rétrospective, conduite sur une période de 15 ans, entre janvier 2004 et décembre 2019. Ont été retenus les cas où le diagnostic était certain ou probable selon les critères de Bohan et Peter. Un total de 14 patients ont été inclus (8 DM et 6 PM), l´âge moyen était de de 48,7 ans. La sex-ratio était de 13F/1H. Les signes généraux existaient dans 71%. Le déficit moteur touchait les muscles des ceintures dans 71% des cas; 85,7% avaient des arthralgies et 14% des arthrites. L´érythème et l´œdème périorbitaire étaient les signes cutanés prédominants. Au bilan, la vitesse de sédimentation était accélérée chez tous les malades et les enzymes musculaires augmentées dans 80%. Les anticorps anti-nucléaires étaient positifs dans 63%. La biopsie musculaire a retrouvé une myosite inflammatoire dans 75%. L'atteinte cardiaque existait dans 14% des cas et pulmonaire dans 21%. Un cancer était associé dans 21,4% des cas. Tous les patients ont reçu une corticothérapie. L´évolution s´est faite vers l´amélioration dans 88%, avec une rechute chez 4 patientes. Dans notre contexte, la DM est plus fréquente que la PM, avec nette prédominance féminine. L'atteinte pulmonaire reste une complication lourde. L´association aux cancers semble fréquente d´où la nécessité d´un bilan systématique de néoplasie au moment du diagnostic et lors du suivi.

The spectrum of idiopathic inflammatory myopathies in South Africa

INTRODUCTION

There are many reports on idiopathic inflammatory myopathies (IIM) but little information from sub-Saharan Africa. We conducted a retrospective study of IIM in a multi-ethnic cohort seen at a single centre in Durban, South Africa.

METHOD

The study included patients who fulfilled the Bohan and Peter or European League Against Rheumatism/American College of Rheumatology criteria for IIM. The information recorded included demographic data, clinical findings, results of investigations, treatment and outcome. Patients with overlap myositis (OM) had myositis and criteria for another connective tissue disease.

RESULTS

There were 104 patients with IIM; 82.7% female and 70.2% African blacks. They included 41 (39.4%) with OM, 26 (25%) polymyositis (PM), 26 (25%) dermatomyositis (DM), six (5.8%) juvenile dermatomyositis and five (4.8%) cancer-associated myositis. Our patients had a younger mean age at diagnosis (36.8 ± 14.7 years) compared with 45-55 years in most other studies. Scleroderma-myositis overlap accounted for 26 (63.4%) of the patients with OM. Patients with OM were significantly younger than PM (p = 0.004) and DM (p = 0.044) and had lower, but not statistically significant, creatine kinase levels at diagnosis compared with PM (p = 0.052) and DM (p = 0.073). Interstitial lung disease was more common in OM (p = 0.001) and PM (p = 0.024) than DM. Oropharyngeal weakness was more common in DM than OM (p = 0.001) and PM (p = 0.032). African blacks were younger (p = 0.028) at diagnosis and had more cardiac abnormalities (p = 0.034) than Indians.

CONCLUSION

The spectrum of IIM in our cohort of mainly African blacks is similar to other studies, with OM being the most frequent subtype. Key Points • As there is limited information on idiopathic inflammatory myopathies (IIM) in sub-Saharan Africa, this study reports the spectrum of IIM in a South African cohort of predominantly African blacks. • Our patients were younger at diagnosis, and overlap myositis was the most common phenotype. • Comparisons with other studies show similarities in the manifestations of IIM.

The Brazilian Society of Rheumatology recommendations on investigation and diagnosis of systemic autoimmune myopathies

BACKGROUND

This research is recommended by the Myopathy Committee of the Brazilian Society of Rheumatology for the investigation and diagnosis of systemic autoimmune myopathies. BODY: A systematic literature review was performed in the Embase, Medline (PubMed) and Cochrane databases, including studies published until October 2018. PRISMA was used for the review, and the articles were evaluated, based on the Oxford levels of evidence. Ten recommendations were developed addressing different aspects of systemic autoimmune myopathy investigation and diagnosis.

CONCLUSIONS

The European League Against Rheumatism/ American College of Rheumatology (EULAR/ACR) classification stands out for the diagnosis of systemic autoimmune myopathies. Muscular biopsy is essential, aided by muscular magnetic resonance images and electroneuromyography in complementary research. Analysis of the factors related to prognosis with the evaluation of extramuscular manifestations, and comorbidities and intense investigation regarding differential diagnoses are mandatory.

Malignancy in myositis

Dermatomyositis is associated with an underlying malignancy in about 24% of cases. This association is also true for polymyositis but is less prominent. The malignancy is usually an adenocarcinoma of the ovary, lung, or gastrointestinal tract in Western countries and nasopharyngeal carcinoma in Southeast Asia, Southern China, and Northern Africa. Factors predictive of malignancy in myositis patients include more severe skin and muscle disease and the absence of overlap connective tissue disease features, such as interstitial lung disease. Anti-p155/140 antibodies have a strong predictive value for malignancy in adult patients. Patients with dermatomyositis or polymyositis require an evaluation for occult malignancy at the time of diagnosis and, in some cases, in the event of a subsequent recurrence. This paraneoplastic phenomenon may stem from an immune reaction to antigens expressed in both cancer cells and regenerating fibers in affected muscle.

Clinical characteristics and outcomes of patients with idiopathic inflammatory myopathies from Jordan 1996-2009

To describe demographic characteristics, clinical features and outcome of Jordanian patients with idiopathic inflammatory myopathies (IIM), a retrospective chart review of all patients diagnosed with IIM at Jordan University Hospital between 1996 and 2009 was carried out. Thirty patients with IIM were identified. Female to male ratio was 1.7:1, with mean age at diagnosis 34.3 ± 9.2 (10-72) years with bimodal presentation at 21 and 49 years and a mean follow-up of 6.5 ± 5.7 years. Eleven patients had polymyositis (PM); 19 patients had dermatomyositis (DM); 1 patient had DM with malignancy; 2 patients had juvenile DM; and 2 patients had DM/PM with other rheumatologic diseases. Raynaud's phenomenon was present in 26% of patients, dysphagia in 40%, fever in 16%, arthralgia/arthritis in 26%, and dyspnea was present in 26% patients. Positive muscle biopsy and EMG were present in 81% and 92% of patients, respectively. Elevated serum creatinine kinase (CK), AST/ALT and LDH were found in 90%, 72%, and 88% of patients at presentation, respectively. Interstitial fibrosis identified on high-resolution computed tomography (HRCT) was found in 7/14 (50%) patients. Restrictive lung disease was present in 16/21 (76%), low diffusion capacity of lung of carbon monoxide (DLCO) in 10/17 (59%) and pulmonary hypertension in only 3/19 (16%) patients tested. Arab Jordanian patients with IIM showed very low prevalence of malignancy, lower mean age than previous reports, and similar other clinical, laboratory and serologic markers, and survival rate to previous reports. Of interest, we found that extra-muscular manifestations were mainly associated with dermatomyositis.