POS0891 REUMA.pt/MYOSITIS – THE PORTUGUESE REGISTRY OF INFLAMMATORY MYOPATHIES

Background

The idiopathic inflammatory myopathies (IMM) module of the Rheumatic Diseases Portuguese Register (Reuma.pt/Myositis) is a tool used to systematically evaluate IIM patients.

Objectives

To clinically characterise the Reuma.pt/Myositis cohort.

Methods

Multicentre open cohort study, including IIM patients registered in Reuma.pt up to January 2022. Data collected included demographic, clinical, and treatment data and patient-reported outcomes. Data were presented as frequencies and median (interquartile range) for categorical and continuous variables, respectively.

Results

280 patients were included, 71.4% female, 89.4% Caucasian, with a median age at diagnosis and disease duration of 48.9 (33.6-59.3) and 5.3 (3.0-9.8) years, respectively. Patients were classified as having definite (N=57/118, 48.3%; N=35/224, 15.6%), likely (N=23/118, 19.5%; N=50/224, 22.3%), or possible (N=2/118, 1.7%; N=46/224, 20.5%) IIM by 2017 EULAR/ACR and Bohan-Peter criteria, respectively. Disease subtypes included dermatomyositis (DM, N=122/280, 43.6%), polymyositis (N=59/280, 21.1%), myositis in overlap syndromes (N=41/280, 14.6%), clinically amyopathic DM (N=17/280, 6.1%), nonspecific myositis (N=13/280, 4.6%), mixed connective tissue disease (N=12/280, 4.3%), immune-mediated necrotizing myositis (N=9/280, 3.2%), and inclusion bodies myopathy (N=7/280, 2.5%). Over the course of the disease, the most common symptoms were proximal muscle weakness (N=180/215, 83.7%), arthralgia (N=127/249, 52.9%), erythema (N=63/166, 38.0%), fatigue (N=47/127, 37.0%), Raynaud’s phenomenon (N=76/234, 32.5%), and dysphagia (N=33/121, 27.3%), and the most common clinical signs were Gottron’s sign (N=75/184, 40.8%), heliotrope rash (N=101/252, 40.1%), Gottron’s papules (N=93/237, 39.2%), and arthritis (N=38/98, 38.8%). Organ involvement included lung (N=78/230, 33.9%), oesophageal (N=40/221, 18.1%), and heart (N=11/229, 4.8%) involvements. Most patients expressed myositis-specific (MSA, N=158/242, 65.3%) and/or myositis-associated (MAA, 112/242, 46.3%) antibodies. The most frequent antibodies were anti-SSA/SSB (N=70/231, 30.3%), anti-Jo1 (N=56/236, 23.7%), and anti-Mi2 (N=31/212, 14.6%). Most patients had a myopathic pattern on electromyogram (N=101/138, 73.2%), muscle oedema in magnetic resonance (N=33/62, 53.2%), and high CK (N=154/200, 55.0%) and aldolase levels (N=74/135, 54.8%) at diagnosis, with median highest CK levels of 1308 (518-3172) and aldolase of 42 (12-121) mg/dL. Neoplasia was found in 11/127 patients (8.7%), most commonly breast (N=3/11, 27.3%), non-melanoma skin (N=2/11, 18.2%), and colorectal (N=2/11, 18.2%) cancer (Table 1). Most patients with cancer-associated myositis had DM (N=8/11, 72.7%) and expressed MSA (N=6/11) and/or MAA (N=3/11). The most used drugs over the course of disease were glucocorticoids (N=201/280, 71.8%), methotrexate (N=117/280, 41.8%), hydroxychloroquine (N=87/280, 31.1%), azathioprine (N=85/280, 30.4%), mycophenolate mofetil (N=56/280, 20.0%), intravenous immunoglobulin (N=55/280, 19.6%), and rituximab (N=45/280, 16.1%). At the last follow-up, there was a median MMT8 of 150 (142-150), modified DAS skin of 0 (0-1), global VAS of 10 (0-50) mm, and HAQ of 0.125 (0.000-1.125).

Table 1.

Autoantibodies in cancer-associated myositis

CancerIIMAutoantibodiesBreastDM (3)Mi2, SRP (+ SSA/SSB), Pm/SclSkin (non-melanoma)Clinically amyopathic DM, PMJo1, SAE1 (+SSA/SSB)ColorectalDM (2)Mi2 (2)KidneyDM-LungDM-LymphomaInclusion bodies myopathy-UnknownDM-

Conclusion

Reuma.pt/Myositis adequately captures the main features of inflammatory myopathies’ patients, depicting in this first report a heterogeneous population, with frequent muscle, joint, skin and lung involvements. Of interest, most patients reached low disease activity at the last follow-up appointment.

Disclosure of Interests

None declared

Effect of policosanol on cerebral ischemia in Mongolian gerbils

Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. An inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. Thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in Mongolian gerbils. Policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. Control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. In the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. In another experimental model, comparison between groups showed that the brain water content of control gerbils (N = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (N = 13), whereas policosanol (200 mg/kg) (N = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. cAMP levels in the brain of control-ligated Mongolian gerbils (N = 8) were significantly lower than those of sham-operated animals (N = 10). The policosanol-treated group (N = 10) showed significantly higher cAMP levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). In conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models in Mongolian gerbils, suggesting a possible therapeutic effect in cerebral vascular disorders.

Oral administration of policosanol inhibits in vitro copper ion-induced rat lipoprotein peroxidation

Policosanol, a new cholesterol-lowering agent, is a mixture of higher aliphatic primary alcohols isolated from sugar cane (Saccharum officinarum L.) wax, which prevents the onset of espontaneously and experimentally induced atherosclerotic lesions in experimental models. Because the oxidation of low-density lipoprotein (LDL) may play a role in the pathogenesis of atherosclerosis, we investigate the effect of policosanol on copper oxidative susceptibility of rat lipoprotein fractions (VLDL + LDL). Rats fed normal diet were treated with policosanol (250-500 mg/kg/day) for up to 4 weeks. EDTA-free lipoprotein particles were oxidized in a cell-free system by the addition of copper ions, and conjugated dienes generation was monitored by changes of optical density at 234 nm. Thiobarbituric acid-reactive substances (TBARS) content and lysine-amino group reactivity were investigated. After administration, there was no change in cholesterol, triglycerides, and phospholipid content of lipoprotein fractions; however, policosanol significantly prolongs the lag time and reduces the propagation rate of diene generation. Also, policosanol reduces TBARS content and increases lysine reactivity in lipoprotein fractions treated with Cu2+. In conclusion, policosanol, in addition to its cholesterol-lowering effect, has other properties that enables it to reduce the potential of lipoprotein to undergo lipid peroxidation. Such effect can be considered of promissory value in the management of atherosclerosis.

Effect of policosanol on in vitro and in vivo rat liver microsomal lipid peroxidation

Policosanol, a defined mixture of high molecular weight aliphatic alcohol isolated and purified from sugar cane (Saccharum officinarum, L) wax is a new cholesterol-lowering agent effective in experimental models, healthy volunteers, and patients with type II hypercholesterolemia. Also, policosanol prevents the onset of spontaneously- and experimentally-induced atherosclerotic lesions and cerebral ischemia in Mongolian gerbils. Free radicals are linked to many diseases including atherosclerosis and ischemia/ reoxidation cellular injury. Therefore, in this study the authors evaluate the antioxidant activity of policosanol on rat liver microsomes. The extent of lipid peroxidation was measured by thiobarbituric acid reactive substances (TBARS). When policosanol was administered orally (100 and 250 mg/kg) for up to 4 weeks, a partial prevention of rat in vitro microsomal lipid peroxidation was noted. The formation of TBARS in microsomes isolated from treated rats was significantly decreased by about 50%, when peroxidation was initiated by Fe3+/ADP/ NADPH, Fe2+/ascorbate and CCl4/NADPH-generating system. Also, oral administration of policosanol in rats provides a partial inhibition of lipid peroxidation, but the mechanism supporting such effect remains to be elucidated. This beneficial effect of policosanol on membrane lipid peroxidation may be useful in protecting to some extent against free radical-associated diseases.

Cholesterol-lowering effect of policosanol on rabbits with hypercholesterolaemia induced by a wheat starch-casein diet

The effect of policosanol, a mixture of high-molecular-weight aliphatic alcohols isolated from sugarcane wax, on casein-induced hypercholesterolaemia in rabbits was studied. When policosanol was administered by the oral route once daily for 30 d (50 mg/kg) the increases in plasma total cholesterol and LDL-cholesterol (LDC-C) were significantly reduced when compared with the control group. The incorporation of 3H2O into sterols in the liver was significantly depressed, suggesting inhibition of hepatic cholesterol biosynthesis. The oral administration of policosanol raised the rate of removal of 125I-labelled LDL from serum. Kinetic parameters calculated following injection of [125I]LDL showed than in casein-fed rabbits, the terminal half-life (t1/2) was significantly decreased after policosanol treatment. The hepatic LDL-binding activity was increased after policosanol administration which suggested that the enhanced clearance was due, at least in part, to increased receptor-mediated uptake of LDL by the liver. Considered together, these results suggest that policosanol can significantly reduce the increase of plasma LDL-C in rabbits fed on a wheat starch-casein diet by reducing cholesterol biosynthesis in the liver. Such an effect could account for the enhancement of LDL catabolism through the receptor-mediated pathway.

Effect of policosanol on the hepatic cholesterol biosynthesis of normocholesterolemic rats

We have suggested previously, measuring 14C-acetate incorporation into free cholesterol, that oral administration of policosanol inhibits hepatic cholesterol biosynthesis in rats. Nevertheless, since acetate has limitations to study cholesterol synthesis in vivo, we now investigate rates of incorporation of labeled water into hepatic sterol after policosanol treatment. Absolute rates of incorporation of 3H-water in sterols were depressed by policosanol by about 20%, giving a more accurate degree of cholesterol biosynthesis inhibition in this species. Since policosanol did not inhibit labeled mevalonate incorporation into cholesterol in rat liver, we also studied the effect of policosanol on hydroxy-methylglutaryl-coenzyme A (HMG-CoA) reductase. Reductase activity assayed in microsomes treated with policosanol remained unchanged, suggesting that cholesterol synthesis is not inhibited by a direct action of policosanol on this enzyme.

Effects of policosanol chronically administered in male monkeys (Macaca arctoides)

Policosanol, administered orally, has shown a cholesterol-lowering effect in different experimental models. Because lipid-lowering therapy is administered chronically, it is necessary to know the effects of these drugs after long-term administration. 18 adult male Macaca arctoides monkeys were used to study the cholesterol-lowering effects and possible toxicity produced by oral administration of policosanol (0.25, 2.5 and 25 mg/kg) for 54 wk. After 8 wk, a significant reduction of serum total cholesterol and low-density lipoprotein cholesterol was observed in policosanol-treated animals when compared with the controls; this effect persisted throughout the study. The animals' behavioural repertoire, physical condition, haematology and blood biochemistry, as well as spermiogram analysis and electrocardiography, were monitored during the study; ophthalmological and pathological anatomy examinations were performed at the end of the administration period. No drug-related toxicity was detected by any examination. The results gave further evidence of the marked and persistent cholesterol-lowering effects of policosanol that had been observed in different experimental models. There was a significant reduction of spontaneous aortic atherosclerotic lesions in treated animals compared with controls. Policosanol (0.25-25 mg/kg) administered orally for 54 wk brought about a persistent reduction in blood cholesterol levels and was very safe and well tolerated during long-term administration.

A 12-month study of policosanol oral toxicity in Sprague Dawley rats

Policosanol is a natural mixture of higher aliphatic primary alcohols. Oral toxicity of policosanol was evaluated in a 12-month study in which doses from 0.5 to 500 mg/kg were given orally to Sprague Dawley (SD) rats (20/sex/group) daily. There was no treatment-related toxicity. Thus, effects on body weight gain, food consumption, clinical observations, blood biochemistry, hematology, organ weight ratios and histopathological findings were similar in control and treated groups. This study supports the wide safety margin of policosanol when administered chronically.

Effects of Policosanol on platelet aggregation in rats

Policosanol is the trivial name of a mixture of high molecular weight alcohols isolated from sugar cane, wherein octacosanol is the main component. The effects of Policosanol treatment on rat platelet aggregation were studied. Depending on the dose, Policosanol (5-20 mg/kg, perorally) inhibited the decrease in circulating platelet counts and collagen-induced malondialdehyde concentration in plasma. In rat clotted whole blood thromboxane B2 formation was inhibited by Policosanol (25 mg/kg). Policosanol (50-200 mg/kg, single doses) inhibited ADP-induced platelet aggregation in platelet-rich plasma, while lower doses (25 mg/kg) did not change responses to ADP significantly. However, rats treated with this dose (25 mg/kg) for 4 weeks showed a significant inhibition of platelet aggregation in PRP when a submaximal ADP concentrations was administered.