Hepatitis C virus infection and myositis: a virus localization study

Extrahepatic Manifestations of Chronic Hepatitis C Virus (HCV) Infection

Hepatitis C virus (HCV) is a well-recognized, major cause of various liver-related conditions such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Apart from liver disease, chronic HCV infection is also associated with several extrahepatic manifestations that can lead to significant morbidity and mortality. These extrahepatic manifestations include essential mixed cryoglobulinemia (EMC), lymphomas, porphyria cutanea tarda, lichen planus, necrolytic acral erythema, glomerulonephritis, subclinical autoantibody formation, immune thrombocytopenia, thyroid disease, Sjögren's disease/sicca symptoms, diabetes mellitus, ocular diseases, musculoskeletal disorders, cardiovascular diseases, neurocognitive dysfunction, and leukocytoclastic vasculitis. We are presenting a case of chronic HCV infection linked to the extrahepatic manifestations of the disease which can be directly related to HCV or indirectly related to EMC from HCV. An awareness and knowledge of these extrahepatic manifestations will highlight the importance of recognizing the symptoms for an early diagnosis and effective anti-viral treatment in order to improve or resolve the long-term complications of chronic HCV infection.

Rare forms of inflammatory myopathies - part I, generalized forms

INTRODUCTION

The idiopathic inflammatory myopathies traditionally comprise dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, anti-synthetase syndrome, and inclusion body myositis. In this review, we aimed to cover the less common forms of generalized myositis.

AREAS COVERED

We identified rare forms of widespread myositis on the basis of list provided by the homepage of the Neuromuscular disease center of Washington University, USA and on the basis of the authors' knowledge. We searched PubMed® and EMBASE® for relevant articles on these forms with the aim of providing as much as possible information on their clinical manifestations as well as guidance on their work-up and treatment.

EXPERT OPINION

There is substantial heterogeneity among the various rare forms of generalized myositis in terms of their frequency and characterization. Some forms are reasonably well defined, while others may not represent truly well-defined diseases, but rather variants of other myopathies. The landscape of rare forms appears to have evolved over time, with some forms now being better characterized, while others, such as SARS-Cov-2- and immune checkpoint inhibitor-related myositis have come to the fore only in recent years. Knowledge about rare forms of myositis can aid in their recognition and treatment.

Genetic rhabdomyolysis within the spectrum of the Spinocerebellar Ataxia type 2 responsive to pregabalin

Background

Spinocerebellar Ataxia type 2 is a slowly progressive adult onset ataxia with a broad clinical presentation.

Case presentation

We describe a man with Spinocerebellar Ataxia type 2 with chronic, severe, and recurrent rhabdomyolysis, as part of the cerebellar ataxia genetic spectrum. Initially rhabdomyolysis was refractory to multiple medications, but entirely resolved and remained in chronic remission with pregabalin.

Conclusions

This is the first report of Spinocerebellar Ataxia type 2 associated with chronic, severe, recurrent rhabdomyolysis as part of its genetic phenotype responsive to pregabalin.

The Neurologic Manifestations of Coronavirus Disease 2019

The coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has so far affected 216 countries and more than 5 million individuals worldwide. The infection is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While pulmonary manifestations are the most common, neurological features are increasingly being recognized as common manifestations of the COVID-19, especially in the cases of severe infection. These include acute cerebrovascular disease, encephalitis, and Guillain-Barre syndrome (GBS). Here, we review the neuropathogenesis of SARS-CoV-2 and the central and peripheral nervous system manifestations of COVID-19.

Endothelium-derived extracellular vesicles promote splenic monocyte mobilization in myocardial infarction

Transcriptionally activated monocytes are recruited to the heart after acute myocardial infarction (AMI). After AMI in mice and humans, the number of extracellular vesicles (EVs) increased acutely. In humans, EV number correlated closely with the extent of myocardial injury. We hypothesized that EVs mediate splenic monocyte mobilization and program transcription following AMI. Some plasma EVs bear endothelial cell (EC) integrins, and both proinflammatory stimulation of ECs and AMI significantly increased VCAM-1-positive EV release. Injected EC-EVs localized to the spleen and interacted with, and mobilized, splenic monocytes in otherwise naive, healthy animals. Analysis of human plasma EV-associated miRNA showed 12 markedly enriched miRNAs after AMI; functional enrichment analyses identified 1,869 putative mRNA targets, which regulate relevant cellular functions (e.g., proliferation and cell movement). Furthermore, gene ontology termed positive chemotaxis as the most enriched pathway for the miRNA-mRNA targets. Among the identified EV miRNAs, EC-associated miRNA-126-3p and -5p were highly regulated after AMI. miRNA-126-3p and -5p regulate cell adhesion- and chemotaxis-associated genes, including the negative regulator of cell motility, plexin-B2. EC-EV exposure significantly downregulated plexin-B2 mRNA in monocytes and upregulated motility integrin ITGB2. These findings identify EVs as a possible novel signaling pathway by linking ischemic myocardium with monocyte mobilization and transcriptional activation following AMI.

Rhabdomyolysis in an HIV cohort: epidemiology, causes and outcomes

Background

The Literature on rhabdomyolysis in the HIV-positive population is sparse and limited. We aimed to explore the incidence, patient characteristics, etiologies and outcomes of rhabdomyolysis in a cohort of HIV-positive patients identified through the Johns Hopkins HIV clinical registry between June 1992 and April 2014.

Methods

A retrospective analysis of 362 HIV-positive patients with non-cardiac CK elevation ≥1000 IU/L was performed. Both inpatients and outpatients were included. Incidence rate and potential etiologies for rhabdomyolysis were ascertained. The development of acute kidney injury (AKI, defined as doubling of serum creatinine), need for dialysis, and death in the setting of rhabdomyolysis were determined. Logistic regression was used to evaluate the association of peak CK level with the development of AKI.

Results

Three hundred sixty two cases of rhabdomyolysis were identified in a cohort of 7079 patients with a 38,382 person years follow-up time. The incidence rate was nine cases per 1000 person-years (95% CI: 8.5–10.5). Infection was the most common etiology followed by compression injury and drug/alcohol use. One-third of cases had multiple potential etiologies. AKI developed in 46% of cases; 20% of which required dialysis. Thirteen percent died during follow-up. After adjustment, AKI was associated with higher CK (OR 2.05 for each 1-log increase in CK [95% CI: 1.40–2.99]), infection (OR 5.48 [95% CI 2.65–11.31]) and higher HIV viral load (OR 1.22 per 1-log increase [95% CI: 1.03–1.45]).

Conclusion

Rhabdomyolysis in the HIV-positive population has many possible causes and is frequently multifactorial. HIV-positive individuals with rhabdomyolysis have a high risk of AKI and mortality.

SHP-1-dependent macrophage differentiation exacerbates virus-induced myositis

Virus-induced myositis is an emerging global affliction that remains poorly characterized with few treatment options. Moreover, muscle-tropic viruses often spread to the CNS, causing dramatically increased morbidity. Therefore, there is an urgent need to explore genetic factors involved in this class of human disease. This report investigates critical innate immune pathways affecting murine virus-induced myositis. Of particular importance, the key immune regulator src homology region 2 domain-containing phosphatase 1 (SHP-1), which normally suppresses macrophage-mediated inflammation, is a major factor in promoting clinical disease in muscle. We show that Theiler's murine encephalomyelitis virus (TMEV) infection of skeletal myofibers induces inflammation and subsequent dystrophic calcification, with loss of ambulation in wild-type (WT) mice. Surprisingly, although similar extensive myofiber infection and inflammation are observed in SHP-1(-/-) mice, these mice neither accumulate dead calcified myofibers nor lose ambulation. Macrophages were the predominant effector cells infiltrating WT and SHP-1(-/-) muscle, and an increased infiltration of immature monocytes/macrophages correlated with an absence of clinical disease in SHP-1(-/-) mice, whereas mature M1-like macrophages corresponded with increased myofiber degeneration in WT mice. Furthermore, blocking SHP-1 activation in WT macrophages blocked virus-induced myofiber degeneration, and pharmacologic ablation of macrophages inhibited muscle calcification in TMEV-infected WT animals. These data suggest that, following TMEV infection of muscle, SHP-1 promotes M1 differentiation of infiltrating macrophages, and these inflammatory macrophages are likely involved in damaging muscle fibers. These findings reveal a pathological role for SHP-1 in promoting inflammatory macrophage differentiation and myofiber damage in virus-infected skeletal muscle, thus identifying SHP-1 and M1 macrophages as essential mediators of virus-induced myopathy.

Neuromuscular diseases associated with chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection is a growing international health problem, and more than 170 million people are chronic carriers. Up to 50% of HCV-positive patients develop at least one extrahepatic manifestation during the course of disease. To varying degrees of certainty, there is evidence of an association between chronic HCV infection and a variety of neuromuscular diseases. The pathogenesis of most extrahepatic diseases remains unclear but possibly includes HCV lymphotropism and/or HCV-induced autoantibodies. The therapeutic approach to HCV-associated autoimmune disorders entails eradication of HCV with one of the recombinant interferon-alpha preparations with or without additional immunosuppressive drugs.

Anti-glutamic Acid decarboxylase antibody-associated ataxia as an extrahepatic autoimmune manifestation of hepatitis C infection: a case report

Extrahepatic immunological manifestations of hepatitis C virus (HCV) are well described. In addition, antiglutamic acid decarboxylase (GAD) antibody-associated cerebellar ataxia is well-established entity. However, there have been no reports in the literature of anti-GAD antibody-associated ataxia as an extrahepatic manifestation of HCV infection. We report the case of a young woman with chronic hepatitis C virus and multiple extrahepatic autoimmune diseases including Sjögren syndrome and pernicious anemia who presented with subacute midline cerebellar syndrome and was found to have positive antiglutamic acid decarboxylase (GAD) antibody in the serum and cerebrospinal fluid. An extensive diagnostic workup to rule out neoplastic growths was negative, suggesting the diagnosis of nonparaneoplastic antiglutamic acid decarboxylase antibody-associated cerebellar ataxia as an additional extrahepatic manifestation of hepatitis C virus infection. The patient failed to respond to high-dose steroids and intravenous immunoglobulin. Treatment with the monoclonal antibody rituximab stabilized the disease. We postulate that anti-GAD associated ataxia could be an extrahepatic manifestation of HCV infection.

Nonbacterial myositis

Infectious myositis is defined as an infection of a skeletal muscle. Infectious myositis is most commonly caused by bacteria; however, a variety of viral, parasitic, and fungal agents may also cause myositis. The pathogenesis of nonbacterial infectious myositis is via direct or hematogenous infection of the musculature or immune mechanisms. Symptoms typically include muscular pain, tenderness, swelling, and/or weakness. The diagnosis of the specific microbe is often suggested by the presence of concordant clinical signs and symptoms, a detailed medical and travel history, and laboratory data. For example, immunocompromised hosts have a heightened risk of fungal myositis, whereas the presence of a travel history to an endemic location and/or eosinophilia may suggest a parasitic cause. Definitive diagnosis requires detecting the organism by specific laboratory testing including serologies, histopathology, and/or cultures. Treatment entails antimicrobial agents against the pathogen, with consideration for surgical drainage for focal purulent collections within the musculature.

Extrahepatic manifestations of hepatitis C virus infection

Hepatitis C virus may cause hepatic and extrahepatic diseases. Extrahepatic manifestations range from disorders for which a significant association with viral infection is supported by epidemiologic and pathogenetic data, to anecdotal observations without clear proof of causality. This article describes the diagnosis and treatment of these diseases.

Bacterial, fungal, parasitic, and viral myositis

Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. A parasitic cause of myositis is suggested by the travel history and presence of eosinophilia. Viruses may cause diffuse muscle involvement with clinical manifestations, such as benign acute myositis (most commonly due to influenza virus), pleurodynia (coxsackievirus B), acute rhabdomyolysis, or an immune-mediated polymyositis. The diagnosis of myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by microbiologic or serologic testing. Therapy is based on the clinical presentation and the underlying pathogen.

Hepatitis C virus does not infect muscle, the intervertebral disk, or the meniscus in patients with chronic hepatitis C

Chronic infection with hepatitis C virus (HCV) is associated with several extrahepatic manifestations, including neuromuscular and joint disorders, and HCV RNA has been detected in muscle fibers of patients with myosistis and chronic hepatitis C. However, whether HCV infects muscle cells in patients without myosistis is unknown. The presence of HCV in other sites of the musculoskeletal system has not been investigated. In the present study the presence of HCV RNA was sought in muscle (2 cases), intervertebral disk (1 case) and meniscus (1 case) samples from patients with chronic hepatitis C. HCV RNA was not detected by reverse transcription and real-time polymerase chain reaction in any of the samples tested. In conclusion, the results do not support a direct role of HCV in musculoskeletal disorders associated with chronic hepatitis C.

Extrahepatic manifestations in patients with chronic hepatitis C virus infection

PURPOSE OF REVIEW

Chronic hepatitis C virus infection often has autoimmune clinical and analytic features. This review analyzes recent data on the close association of chronic hepatitis C virus infection with autoimmune and lymphoproliferative processes.

RECENT FINDINGS

Hepatitis C virus infection has been associated with both organ-specific (thyroiditis, diabetes) and systemic autoimmune diseases. Experimental, virologic, and clinical evidence has demonstrated a close association between hepatitis C virus infection and Sjögren syndrome, with hepatitis C virus-associated Sjögren syndrome being indistinguishable in most cases from the primary form. With respect to rheumatoid arthritis, patients with hepatitis C virus-related polyarthritis and positive rheumatoid factor may fulfill the classification criteria for rheumatoid arthritis. Hepatitis C virus has also been associated with an atypical presentation of antiphospholipid syndrome, as well as with the development of sarcoidosis. A higher prevalence of hematologic processes in patients with hepatitis C virus infection has recently been reported, including cytopenias and lymphoproliferative disorders. Recent data are available on the use of new immunosuppressive and biologic agents (mainly mycophenolate mofetil, anti-tumor necrosis factor agents, and rituximab) in patients with hepatitis C virus infection and autoimmune or lymphoproliferative manifestations.

SUMMARY

There is increasing evidence of a close association of hepatitis C virus infection with autoimmune and hematologic processes. The sialotropism of hepatitis C virus may explain the close association with Sjögren syndrome, and its lymphotropism links the virus to cryoglobulinemia, autoimmune cytopenias, and lymphoma. The substantial overlap between cryoglobulinemic features and the classification criteria for some systemic autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, and polyarteritis nodosa) make the differentiation between mimicking and coexistence difficult.

Seasonal influence on the onset of idiopathic inflammatory myopathies in serologically defined groups

OBJECTIVE

To assess possible seasonal patterns in the onset of polymyositis (PM) and dermatomyositis (DM).

METHODS

The study group comprised 503 patients who met the criteria for probable or definite PM or DM and for whom detailed data on the time of myositis onset were available. Statistical analyses were performed using a Poisson model that assessed associations of ethnicity, sex, autoantibody presence, and month of onset of muscle weakness.

RESULTS

There were no significant seasonal patterns of disease onset in myositis patients as a whole or in the total PM or DM populations. Significant seasonal associations were present, however, in the serologically defined groups. In the 131 patients with antisynthetase autoantibodies who were categorized as non-black, myositis onset peaked in March-April (P = 0.03). Among the antisynthetase-positive patients, the association was predominantly in those with PM (n = 85; P = 0.05) and in men (n = 51; P = 0.042). Patients with anti-signal recognition particle autoantibodies, however, did not have a significant seasonal onset, which is in contrast to previous findings. Patients without myositis-specific autoantibodies showed a significant peak in summer, with myositis onset in June-July (n = 252; P = 0.03); this seasonal association was significant in women (n = 182; P = 0.005), whereas there was no seasonal pattern in men (P = 0.9).

CONCLUSION

These findings, in conjunction with other data, suggest that diverse environmental agents, acting upon different immunogenetic backgrounds, result in distinct immune responses and clinical syndromes in the idiopathic inflammatory myopathies. Our results emphasize the importance of considering more homogeneous disease groups, based on clinicopathologic features, immune responses, ethnicity, and sex, when attempting to decipher the pathogeneses of autoimmune disorders.