Correlation of PMN elastase and PMN elastase-to-neutrophil ratio with disease activity in patients with myositis.

BACKGROUND: Polymorphonuclear (PMN) elastase plays an important role in a variety of inflammatory disorders. Our aim was to analyse PMN elastase in idiopathic inflammatory myopathies (IIMs) and its association with disease activity. METHODS: PMN elastase levels were measured using enzyme-linked immunosorbent assay in serum samples obtained from 74 patients with myositis (58 with dermatomyositis [DM] and 16 with polymyositis [PM]) and 22 healthy controls. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminant capacity of PMN elastase level and PMN elastase-to-neutrophil ratio (ENR) in patients with active and remission myositis. The association of serum PMN elastase level and ENR with disease variables was evaluated in patients with IIMs. The disease specificity of PMN elastase level and ENR was further examined in 60 patients with other systemic autoimmune diseases. RESULTS: PMN elastase level and ENR were significantly higher in patients with active IIMs, DM, and PM than in patients with remission. ROC curve analysis revealed that PMN elastase level and ENR both outperformed creatine kinase (CK), the currently used laboratory marker, and strongly discriminated patients with active disease and those with remission of IIMs, DM, and PM (area under the ROC curve [AUC] 0.9, 0.9, and 0.88 for PMN elastase; AUC 0.96, 0.96, and 1.0 for ENR; AUC 0.72, 0.70, and 0.80 for CK, respectively). PMN elastase level and ENR were positively correlated with myositis disease activity assessment, CK, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, C-reactive protein, and erythrocyte sedimentation rate. PMN elastase level and ENR were higher in the anti-PM-Scl positive myositis group than those in the anti-PM-Scl negative myositis group. Nevertheless, PMN elastase was not a specific disease marker for IIMs when compared with other autoimmune diseases. CONCLUSIONS: PMN elastase, particularly ENR, were significantly correlated with disease activity and could serve as useful biochemical markers for evaluating the disease activity of patients with IIMs. Thus, they are potentially helpful in monitoring disease progression and guiding treatment.

Lack of Heme Oxygenase-1 Induces Inflammatory Reaction and Proliferation of Muscle Satellite Cells after Cardiotoxin-Induced Skeletal Muscle Injury.

Heme oxygenase-1 (HO-1, Hmox1) regulates viability, proliferation, and differentiation of many cell types; hence, it may affect regeneration of injured skeletal muscle. Here, we injected cardiotoxin into gastrocnemius muscle of Hmox1+/+ and Hmox1-/- animals and analyzed cellular response after muscle injury, focusing on muscle satellite cells (SCs), inflammatory reaction, fibrosis, and formation of new blood vessels. HO-1 is strongly induced after muscle injury, being expressed mostly in the infiltrating leukocytes (CD45+ cells), including macrophages (F4/80+ cells). Lack of HO-1 augments skeletal muscle injury, evidenced by increased creatinine kinase and lactate dehydrogenase, as well as expression of monocyte chemoattractant protein-1, IL-6, IL-1ß, and insulin-like growth factor-1. This, together with disturbed proportion of M1/M2 macrophages, accompanied by enhanced formation of arterioles, may be responsible for shift of Hmox1-/- myofiber size distribution toward larger one. Importantly, HO-1-deficient SCs are prone to activation and have higher proliferation on injury. This effect can be partially mimicked by stimulation of Hmox1+/+ SCs with monocyte chemoattractant protein-1, IL-6, IL-1ß, and is associated with increased MyoD expression, suggesting that Hmox1-/- SCs are shifted toward more differentiated myogenic population. However, multiple rounds of degeneration/regeneration in conditions of HO-1 deficiency may lead to exhaustion of SC pool, and the number of SCs is decreased in old Hmox1-/- mice. In summary, HO-1 modulates muscle repair mechanisms preventing its uncontrolled acceleration.

[Antisynthetase syndromes]. / Antisynthetasesyndrome.

Antisynthetase syndromes (ASS) are rare autoimmune diseases. Characteristic is the presence of at least one of the three main symptoms myositis, interstitial lung disease (ILD) and arthritis with possible accompanying symptoms, such as mechanic's hands and feet, Raynaud's disease and/or fever in combination with detection of an aminoacyl-tRNA synthetase antibody in peripheral blood. In addition to myositis, ILD is a frequent and often predominant organ involvement and is responsible for morbidity and mortality. Autoantibodies to 11 aminoacyl-tRNA synthetases are known of which 8 have so far been associated with the clinical manifestation of ASS. The Jo-1 antibody is by far the most frequent one. The antibodies differ in the rate and severity of the main and accompanying symptoms. Treatment with selected immunosuppressive medication depends on the extent and severity of organ involvement. With a 5-year survival rate of approximately 90%, the Jo-1 syndrome has the best prognosis.

More severe disease and slower recovery in younger patients with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase-associated autoimmune myopathy.

Objective: To study disease severity and response to therapy in a large cohort of patients with anti-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)-associated myositis. Methods: Muscle strength, creatine kinase levels and treatments were assessed in anti-HMGCR-positive patients at each clinical visit. Univariate and multivariate analyses were used to analyse the influence of clinical characteristics on strength and the change in strength over time. Whole exome sequencing was performed in a subset of patients. Results: . Among 50 patients followed for ⩾2 years, only 22 (44%) reached full strength with immunosuppressive therapy; even among those with full strength, 55% continued to have CK levels in excess of 500 IU/l and only three could be tapered off immunosuppressive therapy. Both univariate and multivariate analysis showed that patients who were older at disease onset were stronger at all time points (P < 0.001) and improved faster (P < 0.008) than younger patients; a history of statin exposure was not independently associated with the improvement rate. Younger patients were more likely to have refractory disease (P = 0.02) than older patients. Among eight refractory patients with DNA available for testing, whole exome sequencing did not reveal pathogenic mutations in known dystrophy genes. The risk of cancer was not increased in anti-HMGCR myositis patients compared with the general population. Conclusions: Anti-HMGCR myositis is usually a chronic disease requiring long-term immunosuppression. Although younger patients had more severe disease and a worse prognosis than older patients, they did not have evidence of a known co-existing muscular dystrophy to explain their persistent, and sometimes progressive, muscle weakness.

11ß-Hydroxysteroid dehydrogenase type 1 within muscle protects against the adverse effects of local inflammation.

Muscle wasting is a common feature of inflammatory myopathies. Glucocorticoids (GCs), although effective at suppressing inflammation and inflammatory muscle loss, also cause myopathy with prolonged administration. 11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is a bidirectional GC-activating enzyme that is potently upregulated by inflammation within mesenchymal-derived tissues. We assessed the regulation of this enzyme with inflammation in muscle, and examined its functional impact on muscle. The expression of 11ß-HSD1 in response to proinflammatory stimuli was determined in a transgenic murine model of chronic inflammation (TNF-Tg) driven by overexpression of tumour necrosis factor (TNF)-α within tissues, including muscle. The inflammatory regulation and functional consequences of 11ß-HSD1 expression were examined in primary cultures of human and murine myotubes and human and murine muscle biopsies ex vivo. The contributions of 11ß-HSD1 to muscle inflammation and wasting were assessed in vivo with the TNF-Tg mouse on an 11ß-HSD1 null background. 11ß-HSD1 was significantly upregulated within the tibialis anterior and quadriceps muscles from TNF-Tg mice. In human and murine primary myotubes, 11ß-HSD1 expression and activity were significantly increased in response to the proinflammatory cytokine TNF-α (mRNA, 7.6-fold, p < 0.005; activity, 4.1-fold, p < 0.005). Physiologically relevant levels of endogenous GCs activated by 11ß-HSD1 suppressed proinflammatory cytokine output (interkeukin-6, TNF-α, and interferon-γ), but had little impact on markers of muscle wasting in human myotube cultures. TNF-Tg mice on an 11ß-11ß-HSD1 knockout background developed greater muscle wasting than their TNF-Tg counterparts (27.4% less; p < 0.005), with smaller compacted muscle fibres and increased proinflammatory gene expression relative to TNF-Tg mice with normal 11ß-HSD1 activity. This study demonstrates that inflammatory stimuli upregulate 11ß-HSD1 expression and GC activation within muscle. Although concerns have been raised that excess levels of GCs may be detrimental to muscle, in this inflammatory TNF-α-driven model, local endogenous GC activation appears to be an important anti-inflammatory response that protects against inflammatory muscle wasting in vivo. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Inflammation increases pyruvate dehydrogenase kinase 4 (PDK4) expression via the Jun N-Terminal Kinase (JNK) pathway in C2C12 cells.

Chronic inflammation augments the deleterious effects of several diseases, particularly diabetes, cancer, and sepsis. It is also involved in the process of metabolic shift from glucose oxidation to lactate production. Although several studies suggest that the change in activity of the pyruvate dehydrogenase complex (PDC) is a major factor causing this metabolic change, the exact mechanism of the inflammatory state remains unclear. In this study, we investigated the effect of lipopolysaccharide (LPS) on the expression of pyruvate dehydrogenase kinase 4 (PDK4), which is strongly associated with inactivation of the PDC in C2C12 myoblasts. In C2C12 myoblasts, LPS exposure led to increased PDK4 mRNA and protein expression levels as well as lactate production in culture medium. However, the expression levels of other PDK isoenzymes (PDK1 - 3) remained unchanged. Additionally, we observed that LPS treatment induced phosphorylation of Jun N-Terminal Kinases (JNK). To confirm the role of JNK, we inhibited the JNK pathway and observed that PDK4 expression and lactate production were decreased, but p38 and ERK were not significantly changed. Taken together, our results suggest that LPS induces PDK4 expression and alters glucose metabolism via the JNK pathway.

Secreted histidyl-tRNA synthetase splice variants elaborate major epitopes for autoantibodies in inflammatory myositis.

Inflammatory and debilitating myositis and interstitial lung disease are commonly associated with autoantibodies (anti-Jo-1 antibodies) to cytoplasmic histidyl-tRNA synthetase (HisRS). Anti-Jo-1 antibodies from different disease-afflicted patients react mostly with spatially separated epitopes in the three-dimensional structure of human HisRS. We noted that two HisRS splice variants (SVs) include these spatially separated regions, but each SV lacks the HisRS catalytic domain. Despite the large deletions, the two SVs cross-react with a substantial population of anti-Jo-l antibodies from myositis patients. Moreover, expression of at least one of the SVs is up-regulated in dermatomyositis patients, and cell-based experiments show that both SVs and HisRS can be secreted. We suggest that, in patients with inflammatory myositis, anti-Jo-1 antibodies may have extracellular activity.

Therapeutic plasma exchange in antisynthetase syndrome with severe interstitial lung disease.

Antisynthetase syndrome (ASS) is a rare condition characterized by interstitial lung disease (ILD), inflammatory myositis, fever, Raynaud phenomenon, mechanic's hand, and inflammatory polyarthritis in the setting of antibodies to amino acyl-transfer RNA synthetases, with anti-Jo-1 antibody being the most common. Prognosis is very poor especially when there is associated ILD. To date, there is no standardized treatment for ILD associated ASS. Therapy is based on the use of steroids alone or in combination with other immunosuppressive agents, especially in severe or refractory cases. The role of therapeutic plasma exchange (TPE) in the management of this rare condition has not been established. Here, we report a case of severe ILD associated ASS in a 41-year-old woman who did not show clinical or laboratory response after six doses of high dose steroids and a dose of IV cyclophosphamide. Because of the aggressive nature of her disease and poor prognostic indices present, a decision was made to add TPE to her treatment. She underwent five sessions of TPE. At the end of the 5th session, the anti-Jo-1 antibody levels dropped to 3.6 AI (antibody index) and her creatinine kinase (CK) level from 875 to 399 U L(-1) (Units per liter) with overall improvement in her respiratory status. This case suggests TPE may be a promising treatment option in patients with ILD associated ASS refractory to steroids and other immunosuppressive therapy, particularly those with severe disease.

Evaluation of serum leaking enzymes and investigation into new biomarkers for exercise-induced muscle damage.

This investigation determined whether existing muscle damage markers and organ damage markers respond to an acute eccentric exercise protocol and are associated with affected muscle symptoms. Nine healthy-young men completed one-leg calf-raise exercise with their right leg on a force plate. They performed 10 sets of 40 repetitions of exercise at 0.5 Hz with a load corresponding to half of their body weight, with 3 min rest between sets. The tenderness of medial gastrocnemius, lateral gastrocnemius and soleus, and the ankle active range of motion (ROM) were assessed before, immediately after, 24 h and 48 h, 72 h, 96 h and 168 h after exercise. Blood and urine were collected pre-exercise and 2 h, 4 h, 24 h, 48 h, 72 h and 96 h post-exercise. Serum was analyzed for creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and aldolase (ALD) activities. We also determined heart-type fatty acid-binding protein (H-FABP), intestinal-type fatty acid-binding protein (I-FABP) and liver-type fatty acid-binding protein (L-FABP), neutrophil gelatinase-associated lipocalin (NGAL), interleukin (IL)-17A, IL-23, nerve growth factor (NGF), soluble-Endothelial (sE)-selectin, s-Leukocyte (L)-selectin, s-Platelets (P)-selectin, and 8-isoprostane in plasma and urine. The tenderness of proximal and middle gastrocnemius increased significantly 72 h (p < 0.05, p < 0.01) after exercise. Ankle active ROM in dorsal flexion decreased significantly 48 h (p < 0.05) and 72 h (p < 0.01) after exercise. CK and ALD activities significantly increased at 72 h (p < 0.05) and remained elevated at 96 h (p < 0.01) postexercise compared to pre-exercise values. Also, ALD which showed relatively lower interindividual variability was significantly correlated with tenderness of middle gastrocnemius at 72 h. LDH activity significantly increased 96 h postexercise (p < 0.01), whereas the increase in AST and ALT activities 96 h post-exercise was not significantly different from pre-exercise values. There were no significant changes in FABPs, NGAL, IL-17A, IL-23, NGF, selectins and 8-isoprostanes in plasma and urine. In conclusion, calf-raise exercise induced severe local muscle damage symptoms which were accompanied by increases in both serum CK and ALD activities, but we could not detect any changes in examined markers of organ damage, inflammation and oxidative stress. Further research is needed to determine other more sensitive biomarkers and the underlying mechanisms of exercise-induced muscle damage.

Isolated elevation of aldolase in the serum of myositis patients: a potential biomarker of damaged early regenerating muscle cells.

OBJECTIVES: Elevated serum aldolase A levels occur in the absence of elevated creatine kinase M (CK) levels in a subset of myositis patients. This study was undertaken to investigate the cell biology of this unexplained clinical observation. METHODS: Cultured human myoblasts were differentiated in vitro. RNA and protein lysates were prepared and used to determine aldolase and CK gene and protein expression by QPCR and immunoblotting. Cardiotoxin was used to induce muscle injury and repair in an experimental mouse model, and aldolase A and CK were immunoblotted in the muscle lysates. Immunohistochemical staining was performed on myositis patient muscle paraffin sections to assess aldolase A and CK staining in vivo. RESULTS: Aldolase A mRNA and protein expression is highest in differentiating myoblasts, and remains robust throughout differentiation. In contrast, CK mRNA and protein levels are low in undifferentiated myoblasts and become strikingly upregulated as differentiation progresses. Aldolase A protein expression is high in regenerating muscle in the mouse model of injury/repair, while CK expression was low. Immunohistochemical staining of human myositis biopsies showed that muscle cells with the highest levels of aldolase and no CK staining have features of regeneration. CONCLUSIONS: In undifferentiated muscle cells, and those early in the differentiation process, aldolase A is expressed in the absence of CK. Thereafter, both are expressed. We propose that isolated serum aldolase A elevation in myositis patients (i) reflects preferential immune-mediated damage of early regenerative cells, and (ii) is a biomarker of damaged early regenerating muscle cells.

Role of innate immunity in a murine model of histidyl-transfer RNA synthetase (Jo-1)-mediated myositis.

OBJECTIVE: Previous studies in humans and in animal models support a key role of histidyl-transfer RNA synthetase (HisRS; also known as Jo-1) in the pathogenesis of idiopathic inflammatory myopathy. While most investigations have focused on the ability of HisRS to trigger adaptive immune responses, in vitro studies clearly indicate that HisRS possesses intrinsic chemokine-like properties capable of activating the innate immune system. The purpose of this study was therefore to examine the ability of HisRS to direct innate immune responses in a murine model of myositis. METHODS: Following intramuscular immunization with soluble HisRS in the absence of exogenous adjuvant, selected strains of mice were evaluated at different time points for histopathologic evidence of myositis. Enzyme-linked immunosorbent assay-based assessment of autoantibody formation and carboxyfluorescein succinimidyl ester proliferation studies provided complementary measures of B cell and T cell responses triggered by HisRS immunization. RESULTS: Compared to appropriate control proteins, a murine HisRS fusion protein induced robust, statistically significant muscle inflammation in multiple congenic strains of C57BL/6 and NOD mice. Time course experiments revealed that this inflammatory response occurred as early as 7 days postimmunization and persisted for up to 7 weeks. Parallel immunization strategies in DO11.10/RAG-2(-/-) and C3H/HeJ (TLR-4(-/-) ) mice indicated that the ability of murine HisRS to drive muscle inflammation was not dependent on B cell receptor or T cell receptor recognition and did not require Toll-like receptor 4 signaling. CONCLUSION: Collectively, the findings of these experiments support a model in which HisRS can trigger both innate and adaptive immune responses that culminate in severe muscle inflammation that is the hallmark of idiopathic inflammatory myopathy.

Unnecessary diagnostic investigations in benign acute childhood myositis: a case series report.

Benign acute childhood myositis (BACM) is a rare, acute, self-limiting muscle disorder, mainly affecting school-aged boys, with an excellent prognosis, requiring no therapeutic intervention. We report a series of seven previously healthy school-aged children with clinical and laboratory findings suggesting BACM where no specific diagnostic investigations were performed. All of the children were hospitalized without any specific therapeutic intervention and were discharged after two or three days free of symptoms, residual impairment or other complication. This report emphasizes that the correct diagnosis of BACM, by considering the characteristic clinical and laboratory findings of this syndrome and by recognizing more severe pathological conditions, which must be excluded from the diagnosis, can prevent unnecessary diagnostic investigations and reassure both parents and patients of the excellent prognosis.

Clinical heterogeneity and prognostic features of South Australian patients with anti-synthetase autoantibodies.

AIM: To determine the clinical, serological and prognostic features of patients with autoantibodies against three aminoacyl-transfer RNA synthetases (ARS), namely Jo-1 (histidyl-tRNA synthetase), PL-7 (threonyl-tRNA synthetase) and PL-12 (alanyl-tRNA synthetase) in South Australia. METHODS: Patients with autoantibodies against ARS detected by line immunoassay (anti-Jo1, anti-PL7, anti-PL12) or enzyme-linked immunosorbent assay (anti-Jo1) were identified from existing laboratory databases for the period 1994-2009. Demographic, clinical and serological data were obtained by retrospective review of patients' medical records and laboratory databases. RESULTS: Forty-two patients with autoantibodies were identified (anti-Jo1 = 37, anti-PL7 = 4, anti-PL12 = 1). Females were more commonly affected than males (M : F = 12:30). Twenty-one patients had polymyositis (anti-Jo1 = 17, anti-PL7 = 4), seven dermatomyositis (anti-Jo1 = 6, anti-PL12 = 1), 10 overlap syndrome (anti-Jo1 = 10; lupus = 4, scleroderma = 3, Sjögren's syndrome = 2 and rheumatoid arthritis = 2) and four had interstitial lung disease (ILD) only (anti-Jo1 = 4). ILD was present in 69%, polyarthritis in 59% and positive anti-nuclear antibody (ANA) in 43% of patients. Concurrence of autoantibodies against Ro-52 with Jo-1 was seen in 12 patients. The mean follow-up period was 8.3 years (95% CI 5.8-10.8) with 12 deaths. Poor prognostic indicators were age of onset >60 years (P= 0.001), cancer (P= 0.002), negative ANA (P= 0.006) and negative autoantibodies to extractable nuclear antigens (P= 0.02). CONCLUSION: Patients with autoantibodies against ARS present with varied clinical features and occasionally with isolated lung involvement (amyopathic ILD). Older age of onset, malignancy and negative immunologic tests are predictors of poor prognosis. Concurrence of autoantibodies against Jo-1 and Ro-52 may reflect a coupling effect during generation of autoimmunity.

Description and Analysis of a Novel Subtype of the Anti-Synthetase Syndrome Characterized by Frequent Attacks of Fever and Systemic Inflammation in a Single-Center Cohort Study.

Objectives: The aim of this study was to investigate anti-synthetase syndrome (ASyS) patients who presented with recurrent episodes of fever and systemic inflammation. Methods: A retrospective cohort of Chinese ASyS patients (n=126) in our center (between January 2013 and January 2020) was included. Patients presenting with concomitant autoimmune rheumatic diseases or malignancies were subsequently excluded. The number of non-infectious fever attacks and attack frequency were recorded and calculated. Patients with two or more attacks and within the upper three quartiles of attack frequency were defined as high-inflammation group. Univariate and multivariate analyses were carried out to characterize the high-inflammation subtype. Results: Out of 113 eligible patients with an average of 5 years follow up, 25 patients were defined as the high-inflammation group (16 for anti-Jo1, 9 for anti-PL7), with an average of 1.12 attack/patient-year. Compared to low-inflammation group (0-1 attack only and a frequency lower than 0.5 attack/patient-year), the high-inflammation group had higher occurrence of fever and rapid progressive interstitial lung disease (RPILD) as the first presentation (84% vs. 21% and 40% vs. 9%, respectively, both p<0.01). Anti-PL-7 was related to the more inflammatory phenotype (p=0.014). Cumulative disease-modifying agent exposures (>=3) were much higher in the high-inflammation group (60% vs. 26%), while biological agents, i.e., rituximab and tocilizumab, showed better "drug survival" for Jo-1+ and PL-7+ ASyS patients with high inflammation, respectively, in our cohort. Conclusions: ASyS with recurrent systemic inflammatory episodes reflects a subtype of more aggressive and refractory disease in the spectrum of ASyS. Increased awareness of this subtype might lead to more appropriate management.

Safety and Antitumor Activity of Repeated ASP3026 Administration in Japanese Patients with Solid Tumors: A Phase I Study.

BACKGROUND AND OBJECTIVE: Anaplastic lymphoma kinase gene rearrangements (ALKr) resulting in EML4-ALK proteins occur in a subset of solid tumors and are targeted by ALK inhibitors. Given the development of drug resistance to ALK inhibitors, ALK inhibitors with different kinase selectivity are required. METHODS: This phase I, non-randomized, open-label study evaluated the dose-limiting toxicity (DLT), safety, pharmacokinetics, and antitumor activity of ASP3026, a second-generation ALK inhibitor, in Japanese patients with solid tumors. Between 1 June 2011 and 20 January 2014, 29 patients received different daily doses of ASP3026 in the escalation (25 mg, n = 3; 50 mg, n = 3; 75 mg, n = 3; 125 mg, n = 4; 200 mg, n = 3; or 325 mg, n = 7) and expansion (200 mg, n = 6) cohorts. RESULTS: Three patients had DLTs at the 325-mg dose: cataract exacerbation, increased aspartate transaminase and alanine transaminase, and impaired hepatic function (all Grade 3 severity). Thus, the maximum tolerated dose was 200 mg. The treatment-emergent adverse event incidence was 100%; the most common events were nausea (n = 8, 27.6%), decreased appetite (n = 10, 34.5%), and fatigue (n = 9, 31.0%) of mild or moderate severity. Six patients were positive for ALK protein and three had ALKr. Two patients achieved partial responses: one with Ewing sarcoma (75-mg dose group) and one with an ALKr-positive inflammatory myofibroblastic tumor (125-mg dose group). CONCLUSION: ASP3026 at a 200-mg dose may provide therapeutic benefit for patients with solid tumors, with a tolerable safety profile. CLINICAL TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov under the identifier NCT01401504 on July 25, 2011.

Statin use in patients with non-HMGCR idiopathic inflammatory myopathies: A retrospective study.

BACKGROUND: Statins are the most widely used lipid lowering therapies which reduce cardiovascular risk, but are associated with muscular adverse events (AEs). Idiopathic inflammatory myopathies (IIM) are autoimmune diseases of the muscle with higher risk of cardiovascular disease. More data is needed regarding statin safety in patients with intrinsic muscle disease such as IIM. HYPOTHESIS: Statins are tolerated in patients with IIM without leading to significant increase in muscular AEs. METHODS: Statin use was retrospectively examined in a longitudinal IIM cohort. Safety analysis included assessment of muscular and nonmuscular AEs by chart review. IIM patients receiving a statin during the cohort follow-up period were matched to IIM patients not receiving a statin for comparative analysis of longitudinal outcomes. RESULTS: 33/214 patients had a history of statin use. 63% started for primary prevention, while others were started for clinical ASCVD events, vascular surgery, IIM related heart failure, and cardiac transplantation. A high intensity statin was used in nine patients with non-HMGCR myositis, and tolerated in 8/9 patients. Statin related muscular AE was noted in three patients. There were no cases of rhabdomyolysis, or statin related nonmuscular AEs in a median observation period of 5 years. In patients newly started on statins during cohort follow-up (n = 7) there was no change in disease activity after statin initiation. Long term outcomes were not different between statin and nonstatin IIM control groups. CONCLUSION: Statins were well tolerated in patients with non-HMGCR positive IIM. Given the accelerated atherosclerotic risk in IIM patients, further prospective studies of statin safety in IIM patients are warranted.

[Elevated serum aldolase activity in a patient of non-eosinophilic myofasciitis and synovitis with perifascicular atrophy].

A 35-year-old man suffered from myalgia and joint pain on walking for 5 months. Physical and neurological examinations revealed dermal sclerosis, skin swelling, redness of forearms, Raynaud's phenomenon, joint pain, myalgia and muscle weakness. Eosinophilia was not found and serum creatine kinase activity was normal, while aldolase was markedly elevated. Abnormal signals suggesting synovitis and myofasciitis were found on MRI images. Biopsy of the fascia of quadriceps femoris showed perivascular mononuclear cell infiltration. A muscle biopsy showed mononuclear cell infiltration mainly in the perimysium extending to the endmysium. Eosinophilic cells were not found, Perifascicular atrophy was observed. Corticosteroid therapy improved clinical symptoms and serum aldolase level. We diagnosed him as non-eosinophilic myofasciitis and synovitis with perifascicular atrophy. The serum aldolase activity is usuful for diagnosis and for monitoring the disease activity.

Muscle inflammation induces a protein kinase Cepsilon-dependent chronic-latent muscle pain.

UNLABELLED: Skeletal muscle injuries can induce chronic pain, but the underlying mechanism is unknown. One possible cause has been suggested to be an increased sensitivity to inflammatory mediators. We demonstrate that self-limited inflammatory hyperalgesia induced by intramuscular carrageenan (lasting approximately 5 days) results in a state of chronic-latent hyperalgesia, revealed by injection of prostaglandin E(2) (PGE(2)) 10 days after carrageenan at the same site. In carrageenan-pretreated muscle, PGE(2) produced hyperalgesia that was unattenuated even 14 days after injection, markedly longer than the 4-hour hyperalgesia induced by PGE(2) in naive rats. This chronic-latent hyperalgesia was reversed as well as prevented by spinal intrathecal injection of oligodeoxynucleotide antisense to protein kinase Cepsilon, a second messenger implicated in long-lasting plasticity in cutaneous nociceptors. PERSPECTIVE: We describe a novel experimental model for chronic muscle pain, produced by mild acute muscle inflammation, that has clinical significance since it has the potential to reveal cellular processes by which acute inflammation or muscle trauma underlies chronic muscle pain.

Dysphagia secondary to focal inflammatory myopathy and consequent dorsiflexion of the tongue in a dog.

A 14-month-old female pitbull terrier mix was presented for evaluation of dysphagia of 8 months' duration secondary to intermittent dorsiflexion of the tongue apex. Physical and neurological examinations were unremarkable with the exception of the dorsiflexed tongue. Serum creatine kinase activity was increased (703 IU/L, reference interval: 55 to 257 IU/L), and electromyography of the tongue demonstrated areas of fibrillation potentials. Histopathology of the tongue showed myopathic changes with excessive variability in myofibre size and endomysial fibrosis. Cytochemical stains verified mixed mononuclear cells throughout the endomysium and perimysium consistent with a chronic inflammatory myopathy. No improvement was reported following prednisone administration; although the dog was able to prehend kibble, it needed assistance when drinking water. This is the first report documenting a focal lingual myopathy in a non-corgi breed and highlights the utility of determining creatine kinase activity and obtaining tongue biopsies when warranted in dysphagic animals.

Calcium/Calmodulin-Dependent Protein Kinase IV (CaMKIV) Mediates Acute Skeletal Muscle Inflammatory Response.

The objective of this study is to investigate the role of Calmodulin-dependent protein kinase IV (CaMKIV) in Cardiotoxin (CTX)-induced mice muscle inflammation. CTX injection i.m. was performed to induce B6 mice acute tibialis anterior (TA) muscle injury. The mice were then injected i.p. with the recombinant CaMKIV protein or its antagonist KN-93. Immunoblotting was used to assess Calmodulin (CaM) and CaMKIV levels. Immunofluorescence was used to detect intramuscular infiltration or major histocompatibility complex (MHC)-I expression in damaged muscle. The extent of infiltration was evaluated by fluorescent intensity analysis. Cytokines/chemokines levels were determined by qPCR. CaMKIV gene knockdown in C2C12 cells was performed in order to evaluate the effects of CaMKIV on immuno-behavior of muscle cells. CTX administration induced a strong up-regulation of CaM and p-CaMKIV levels in infiltrated mononuclear cells and regenerated myofibers. In vivo adding of the recombinant CaMKIV protein enhanced intramuscular infiltration of monocytes/macrophages in damaged muscle and increased the number of proinflammatory Ly-6C+F4/80+ macrophage cells. CaMKIV protein treatment induced a striking up-regulation of mRNA levels of IL-1, IL-6, MCP-1, and MCP-3 in CD45+ cells sorted from damaged muscle; increased the infiltration of CD8+ T cells; and induced the up-regulation of MHC-I in partial regenerated myofibers, which was rarely observed in muscle damage alone. Additionally, CaMKIV protein treatment diminished the regulatory T cells (Tregs) number and led to the damaged TA muscle repair delay. In vitro CaMKIV gene knockdown reversed IFN-γ-induced up-regulation of MHC-I/II and TLR3 in the differentiated C2C12 myotubes. CaMKIV can act as an immunostimulation molecule and enhances the acute muscle inflammatory responses.