Abstract
Objective
Among specific autoantibodies in DM, the anti–small ubiquitin-like modifier activating enzyme (SAE) antibody is rare. We aim to describe the clinical characteristics, cancer ...prevalence, and muscle pathology of anti-SAE–positive DM.
Methods
Patients with a diagnosis of DM and sera positive for the anti-SAE antibody were recruited from 19 centres in this retrospective observational study. The available muscular biopsies were reviewed. We conducted a comparison with anti-SAE–negative DM and a review of the literature.
Results
Of the patients in the study (n = 49), 84% were women. Skin involvement was typical in 96% of patients, with 10% having calcinosis, 18% ulceration and 12% necrosis; 35% presented with a widespread skin rash. Muscular disease affected 84% of patients, with mild weakness Medical Research Council (MRC) scale 4 (3, 5), although 39% of patients had dysphagia. Muscular biopsies showed typical DM lesions. Interstitial lung disease was found in 21% of patients, mainly with organizing pneumonia pattern, and 26% of patients showed dyspnoea. Cancer-associated myositis was diagnosed in 16% of patients and was responsible for the majority of deaths, its prevalence being five times that of the general population. IVIG therapy was administered to 51% of the patients during the course of the disease. Comparison with anti-SAE–negative DM (n = 85) showed less and milder muscle weakness (P = 0.02 and P = 0.006, respectively), lower creatinine kinase levels (P < 0.0001) and less dyspnoea (P = 0.003).
Conclusion
Anti-SAE positive DM is a rare subgroup associated with typical skin features but a potentially diffuse rash, a mild myopathy. Interstitial lung disease defines an organizing pneumonia pattern. Cancer associated DM prevalence is five times that of the general population.
Trial registration
ClinicalTrials.gov, http://clinicaltrials.gov, NCT04637672.
Prion diseases are fatal neurodegenerative disorders caused by accumulation of abnormal prion protein (protease-resistant prion, PrPres). PrPres accumulation is also detected in lymphoid organs after ...peripheral infection. Several studies suggest that follicular dendritic cells (FDC) could be the site of PrPres retention and amplification. Here we show that human follicular dendritic cells can express normal cellular prion protein (PrPc) both in situ and in vitro. When tonsillar cryosections were treated with anti-PrP antibody, the label was found on some very delicate cell extensions inside the lymphoid follicles, especially in the germinal centres. These extensions react with DRC1 antibody, used frequently to label FDC. Other structures labelled with anti-PrP antibody were the keratinocytes. To confirm the ability of FDC to synthesise PrPc, we isolated FDC by a non-enzymatic procedure and cultured them. By cytochemistry and flow cytometry it was clearly shown that FDC do produce PrPc.
Civil society at large and all caregivers, whether at home or within institutions, are involved in palliative care However, procedures may vary considerably, excluding a single approach. So as to ...best adapt their responses, the authors recorded everyone's expectations. Such a participatory methodology is, sine 1990, behind the establishment of local networks providing assistance, support and training to physicians non-specialized in palliative care (general practitioners, specialists, students or residents facing specific aspects of this medical management, as well as other health and social workers).
Dervillite was described in 1941 on the basis of the morphology of tiny crystals (≤ 0.3 mm) and qualitative chemistry as a compound of lead, sulphur and antimony, and possibly also bismuth. A ...reinvestigation of the original sample proves the chemical data to be erroneous and based on chemical tests on material that was apparently not extracted from the dervillite crystals ; the material was taken from powders prepared for X-ray work that owing to war circonstances could not be completed.
The holotype specimen from Sainte-Marie-aux-Mines (Haut-Rhin, France) (Mus. Nat. d'Hist. Nat. Paris, n° 1531) is the only one known, and carries few crystals. A restudy of 4 crystals has permitted a fully revised description. Goniometric study confirms the original measurements and authenticates the material used. Dervillite is monoclinic, P2/a, with : a = 6.833, b = 12.932, c = 9.638Å, β = 99°33', in good agreement with the goniometry. An X-ray powder pattern was fully indexed ; strongest diffractions : 3.075 (10) 013 ; 3.019 (8) 201, -132 ; 2.843 (5) -141, 023 ; 3.251 (3) -211 ; 2.659 (3) 230.
The reflectivity is a little less than that of the tetrahedrite group. VHN 19.5 kg/mm2 under 50-100 g load. Microprobe analysis gives Ag = 61.39 %, As = 19.35 %, S = 18.06 %, ∑ = 98.48 %, and the deficiency is believed to be mainly As lost by heating under electron beam. Pb, Sb, and Bi were not found. This gives the formula Ag2AsS2. The density could not be measured for lack of suitable and sufficient material. On the basis of the formula Ag8As4S8, and with Z = 2, dcalc. is 5.62. A crystal structure study is in progress.
The holotype specimen and a slide with a few crystals are preserved in the Museum National d'Histoire Naturelle de Paris. An other slide with one crystal is preserved in the Ecole Nationale Supérieure des Mines de Paris.
La dervillite a été décrite en 1941 sur la base d'une étude goniométrique de minuscules cristaux (≤0,3 mm) et d'une analyse qualitative indiquant la présence de Pb, S et Sb, peut-être aussi Bi. Un nouvel examen de l'échantillon type a montré que les données chimiques étaient fausses, et basées sur des essais qui n'ont manifestement pas été menés sur des cristaux de dervillite, mais sur l'une ou l'autre poudre préparée pour des travaux aux rayons X. La confusion était due aux circonstances particulières causées par l'évacuation de l'Université de Strasbourg en 1939, au cours de ces recherches sur la dervillite.
Le spécimen holotype de Sainte-Marie-aux-Mines (Haut-Rhin, France) (Mus. Nat. Hist. Nat. Paris, n° 1531) est le seul connu et contient quelques cristaux. Une étude de quatre d'entre eux a permis une redéfinition complète de l'espèce. L'étude goniométrique confirme les mesures effectuées sur un cristal en 1935 et son identité avec ceux qui ont servi à cette présente étude. La dervillite est monoclinique, P2/a, avec : a = 6,833 ; b = 12,932 ; c = 9,638Å ; β = 99°33', en parfait accord avec les mesures goniométriques. Les principales raies du diagramme de poudre sont : 3,075 (10) 013 ; 3,019 (8) 201, -132 ; 2,843 (5) -141, 023 ; 3,251 (3) -211 ; 2,659 (3) 230.
Le pouvoir réflecteur de la dervillite est un peu plus faible que celui du groupe de la tétraédrite. VHN 19,5 kg/mm2 pour un poids de 50-100 g. L'analyse à la microsonde donne : Ag = 61,39 %, As = 19,35 %, S = 18,06 %, ∑ = 98,48 % ; le déficit observé est probablement dû à une perte en arsenic en raison de réchauffement sous le faisceau électronique. Pb, Sb et Bi n'ont pas été détectés. Ces résultats conduisent à la formule Ag2AsS2. La densité n'a pu être mesurée du fait du manque de produit. Sur la base de la formule Ag8As4S8 et Z = 2, dcalc. is 5,62. Une étude de la structure est en cours.
Le spécimen holotype et une section contenant quelques cristaux sont conservés au Muséum National d'Histoire Naturelle de Paris. Une autre section polie contenant un cristal de dervillite est conservée à l'Ecole Nationale Supérieure des Mines de Paris.
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