Management of chikungunya arthritis

4-Substituted-2-Thiazole Amides as Viral Replication Inhibitors of Alphaviruses

2-(Methylthio)-N-(4-(naphthalen-2-yl)thiazol-2-yl)nicotinamide 1 was identified as an inhibitor against Chikungunya virus (CHIKV) with good antiviral activity [EC50 = 0.6 μM; EC90 = 0.93 μM and viral titer reduction (VTR) of 6.9 logs at 10 μM concentration] with no observed cytotoxicity (CC50 = 132 μM) in normal human dermal fibroblast (NHDF) cells. Structure-activity relationship (SAR) studies to further improve the potency, efficacy, and drug-like properties of 1 led to the discovery of a new potent inhibitor N-(4-(3-((4-cyanophenyl)amino)phenyl)thiazol-2-yl)-2-(methylthio)nicotinamide 26, which showed a VTR of 8.7 logs at 10 μM against CHIKV and an EC90 of 0.45 μM with considerably improved MLM stability (t1/2 = 74 min) as compared to 1. Mechanism of action studies show that 26 inhibits alphavirus replication by blocking subgenomic viral RNA translation and structural protein synthesis. The in vivo efficacy studies of compound 26 on CHIKV infection in mice are reported.

Granulocyte colony-stimulating factor protects against arthritogenic alphavirus pathogenesis in a type I IFN-dependent manner

Arthritogenic alphaviruses cause disease characterized by fever, rash, and incapacitating joint pain. Alphavirus infection stimulates robust inflammatory responses in infected hosts, leading to the upregulation of several cytokines, including granulocyte colony-stimulating factor (G-CSF). G-CSF is secreted by endothelial cells, fibroblasts, macrophages, and monocytes and binds to colony stimulating factor 3 receptor (CSF3R, also known as G-CSFR) on the surface of myeloid cells. G-CSFR signaling initiates proliferation, differentiation, and maturation of myeloid cells, especially neutrophils. Importantly, G-CSF has been found at high levels in both the acute and chronic phases of chikungunya disease; however, the role of G-CSF in arthritogenic alphavirus disease remains unexplored. Here, we sought to test the effect of G-CSF on chikungunya virus (CHIKV) and Mayaro virus (MAYV) infection using G-CSFR-deficient mice (G-CSFR-/-). We observed sustained weight loss in G-CSFR-/- mice following viand MAYV infection compared to wild-type mice. Furthermore, G-CSFR-/- mice had a significantly higher percentage of inflammatory monocytes and reduction in neutrophils throughout infection. The difference in weight loss in G-CSFR-/- mice induced by alphavirus infection was corrected by blocking type I IFN signaling. In summary, these studies show that type I IFN signaling contributes to G-CSFR mediated control of arthritogenic alphavirus disease.

Lack of pathogenic involvement of CCL4 and its receptor CCR5 in arthritogenic alphavirus disease

Arthritogenic alphaviruses, including chikungunya virus (CHIKV), Mayaro virus (MAYV), Ross River virus (RRV), and O'nyong nyong virus (ONNV) are emerging and reemerging viruses that cause disease characterized by fever, rash, and incapacitating joint swelling. Alphavirus infection induces robust immune responses in infected hosts, leading to the upregulation of several cytokines and chemokines, including chemokine C ligand 4 (CCL4). CCL4 is a chemoattractant for immune cells such as T cells, natural killer cells, monocytes/macrophages, and dendritic cells, recruiting these cells to the site of infection, stimulating the release of proinflammatory mediators, and inducing T cell differentiation. CCL4 has been found at high levels in both the acute and chronic phases of chikungunya disease; however, the role of CCL4 in arthritogenic alphavirus disease development remains unexplored. Here, we tested the effect of CCL4 on MAYV infection in mice through antibody depletion and treatment with recombinant mouse CCL4. We observed no differences in mice depleted of CCL4 or treated with recombinant CCL4 in terms of disease progression such as weight loss and footpad swelling or the development of viremia. CCL4 uses the G protein-coupled receptor C-C chemokine receptor type 5 (CCR5). To determine whether CCR5 deficiency would alter disease outcomes or virus replication in mice, we inoculated CCR5 knockout (CCR5-/-) mice with MAYV and observed no effect on disease development and immune cell profile of blood and footpads between CCR5-/- and wild type mice. These studies failed to identify a clear role for CCL4 or its receptor CCR5 in MAYV infection.

Management of postinfectious inflammatory arthritis

PURPOSE OF REVIEW

Postinfectious inflammatory arthritis can result from various pathogens, including bacteria, viruses, fungi, and parasites. Prompt identification and treatment of acute infection is vital, but some cases progress to chronic arthritis despite successful treatment of infection. Postinfectious inflammatory arthritis varies from mild, self-limited arthralgia to severe, refractory arthritis, necessitating ongoing disease-modifying treatment. This review explores the spectrum of postinfectious inflammatory arthritis to provide insights into effective management.

RECENT FINDINGS

Research continues regarding the benefit of antimicrobial therapy, beyond treatment of the acute infection, to diminish the severity of postinfectious inflammatory arthritis. Following treatment of acute infection, most cases are self-limited so treatment is symptomatic. However, a difficult-to-predict fraction of cases develop chronic postinfectious inflammatory arthritis that can be challenging to manage. Recently, as more biologic, and targeted synthetic DMARDs have become available, treatment options have expanded.

SUMMARY

In this article, we use the term 'postinfectious inflammatory arthritis' rather than 'reactive arthritis' because it describes a broader spectrum of diseases and emphasizes the common pathogenesis of a postinfectious inflammatory process. We summarize the conventional therapies and recent management developments for the most frequently encountered postinfectious inflammatory arthritides.

Anodal tDCS over the motor cortex improves pain but not physical function in chronic chikungunya arthritis: Randomized controlled trial

BACKGROUND

Chikungunya virus (CHIKV) is a globally prevalent pathogen, with outbreaks occurring in tropical regions. Chronic pain is the main symptom reported and is associated with decreased mobility and disability. Transcranial direct current stimulation (tDCS) is emerging as a new therapeutic tool for chronic arthralgia.

OBJECTIVE

To evaluate the effectiveness of 10 consecutive sessions of anodal tDCS on pain (primary outcome) in participants with chronic CHIKV arthralgia. Secondary outcomes included functional status, quality of life, and mood.

METHODS

In this randomized, double-blind, placebo-controlled trial, 30 participants with chronic CHIKV arthralgia were randomly assigned to receive either active (n = 15) or sham (n = 15) tDCS. The active group received 10 consecutive sessions of tDCS over M1 using the C3/Fp2 montage (2 mA for 20 min). Visual analog scale of pain (VAS), health assessment questionnaire (HAQ), short-form 36 health survey (SF-36), pain catastrophizing scale, Hamilton anxiety scale (HAS), timed up and go (TUG) test, lumbar dynamometry, 30-s arm curl and 2-min step test were assessed at baseline, day 10 and at 2 follow-up visits.

RESULTS

There was a significant interaction between group and time on pain (p = 0.03; effect size 95 % CI 0.9 (-1.67 to -0.16), with a significant time interaction (p = 0.0001). There was no interaction between time and group for the 2-minute step test (p = 0.18), but the groups differed significantly at day 10 (p = 0.01), first follow-up (p = 0.01) and second follow-up (p = 0.03). HAQ and SF-36 improved but not significantly. There was no significant improvement in mental health, and physical tests.

CONCLUSION

tDCS appears to be a promising intervention for reducing pain in participants with chronic CHIKV arthralgia, although further research is needed to confirm these findings and explore potential long-term benefits.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC): RBR-245rh7.

Design, synthesis, and lead optimization of piperazinyl-pyrimidine analogues as potent small molecules targeting the viral capping machinery of Chikungunya virus

The worldwide re-emerge of the Chikungunya virus (CHIKV), the high morbidity associated with it, and the lack of an available vaccine or antiviral treatment make the development of a potent CHIKV-inhibitor highly desirable. Therefore, an extensive lead optimization was performed based on the previously reported CHVB compound 1b and the reported synthesis route was optimized - improving the overall yield in remarkably shorter synthesis and work-up time. Hundred analogues were designed, synthesized, and investigated for their antiviral activity, physiochemistry, and toxicological profile. An extensive structure-activity relationship study (SAR) was performed, which focused mainly on the combination of scaffold changes and revealed the key chemical features for potent anti-CHIKV inhibition. Further, a thorough ADMET investigation of the compounds was carried out: the compounds were screened for their aqueous solubility, lipophilicity, their toxicity in CaCo-2 cells, and possible hERG channel interactions. Additionally, 55 analogues were assessed for their metabolic stability in human liver microsomes (HLMs), leading to a structure-metabolism relationship study (SMR). The compounds showed an excellent safety profile, favourable physicochemical characteristics, and the required metabolic stability. A cross-resistance study confirmed the viral capping machinery (nsP1) to be the viral target of these compounds. This study identified 31b and 34 as potent, safe, and stable lead compounds for further development as selective CHIKV inhibitors. Finally, the collected insight led to a successful scaffold hop (64b) for future antiviral research studies.

Antiviral, Cytoprotective, and Anti-Inflammatory Effect of Ampelozizyphus amazonicus Ducke Ethanolic Wood Extract on Chikungunya Virus Infection

Chikungunya fever, a debilitating disease caused by Chikungunya virus (CHIKV), is characterized by a high fever of sudden onset and an intense arthralgia that impairs individual regular activities. Although most symptoms are self-limited, long-term persistent arthralgia is observed in 30-40% of infected individuals. Currently, there is no vaccine or specific treatment against CHIKV infection, so there is an urgent need for the discovery of new therapeutic options for CHIKF chronic cases. This present study aims to test the antiviral, cytoprotective, and anti-inflammatory activities of an ethanol extract (FF72) from Ampelozizyphus amazonicus Ducke wood, chemically characterized using mass spectrometry, which indicated the major presence of dammarane-type triterpenoid saponins. The major saponin in the extract, with a deprotonated molecule ion m/z 897 [M-H]-, was tentatively assigned as a jujubogenin triglycoside, a dammarane-type triterpenoid saponin. Treatment with FF72 resulted in a significant reduction in both virus replication and the production of infective virions in BHK-21-infected cells. The viability of infected cells was assessed using an MTT, and the result indicated that FF72 treatment was able to revert the toxicity mediated by CHIKV infection. In addition, FF72 had a direct effect on CHIKV, since the infectivity was completely abolished in the presence of the extract. FF72 treatment also reduced the expression of the major pro-inflammatory mediators overexpressed during CHIKV infection, such as IL-1β, IL-6, IL-8, and MCP-1. Overall, the present study elucidates the potential of FF72 to become a promising candidate of herbal medicine for alphaviruses infections.

Chikungunya fever

Chikungunya virus is widespread throughout the tropics, where it causes recurrent outbreaks of chikungunya fever. In recent years, outbreaks have afflicted populations in East and Central Africa, South America and Southeast Asia. The virus is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Chikungunya fever is characterized by severe arthralgia and myalgia that can persist for years and have considerable detrimental effects on health, quality of life and economic productivity. The effects of climate change as well as increased globalization of commerce and travel have led to growth of the habitat of Aedes mosquitoes. As a result, increasing numbers of people will be at risk of chikungunya fever in the coming years. In the absence of specific antiviral treatments and with vaccines still in development, surveillance and vector control are essential to suppress re-emergence and epidemics.

Ten sessions of transcranial direct current stimulation for chronic chikungunya arthralgia: study protocol for a randomised clinical trial

INTRODUCTION

The chikungunya virus infection is still an epidemic in Brazil with an incidence of 59.4 cases per 100 000 in the Northeast region. More than 60% of the patients present relapsing and remitting chronic arthralgia with debilitating pain lasting for years. Transcranial direct current stimulation (tDCS) appears promising as a novel neuromodulation approach for pain-related networks to alleviate pain in several pain syndromes. Our objective is to evaluate the effectiveness of tDCS (C3/Fp2 montage) on pain, muscle strength, functionality and quality of life in chronic arthralgia.

METHODS AND ANALYSIS

This protocol is a single-centre, parallel-design, double-blind, randomised, sham-controlled trial. Forty participants will be randomised to either an active or sham tDCS. A total of 10 sessions will be administered over 2 weeks (one per weekday) using a monophasic continuous current with an intensity of 2 mA for 20 min. Participants will be evaluated at baseline, after the 10th session, 2 weeks and 4 weeks after intervention.

PRIMARY OUTCOME

pain assessed using numeric rating scale and algometry.

SECONDARY OUTCOMES

muscle strength, functionality and quality of life. The effects of stimulation will be calculated using a mixed analysis of variance model.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of the Faculty of Health Sciences of Trairí, Federal University of Rio Grande do Norte (No. 2.413.851) and registered on the Brazilian Registry of Clinical Trials. Study results will be disseminated through presentations at conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

RBR-469yd6.

Characterization and Involvement of Exosomes Originating from Chikungunya Virus-Infected Epithelial Cells in the Transmission of Infectious Viral Elements

The Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that affects the world's popula-tion with chikungunya disease. Adaptation of the viral life cycle to their host cells' environment is a key step for establishing their infection and pathogenesis. Recently, the accumulating evidence advocates a principal role of extracellular vesicles (EVs), including exosomes, in both the infection and pathogenesis of infectious diseases. However, the participation of exosomes in CHIKV infec-tion and transmission is not well clarified. Here, we demonstrated that the CHIKV RNA and pro-teins were captured in exosomes, which were released by viral-infected epithelial cells. A viral genomic element in the isolated exosomes was infectious to naïve mammalian epithelial cells. The assay of particle size distribution and transmission electron microscopy (TEM) revealed CHIKV-derived exosomes with a size range from 50 to 250 nm. Treatments with RNase A, Triton X-100, and immunoglobulin G antibodies from CHIKV-positive patient plasma indicated that in-fectious viral elements are encompassed inside the exosomes. Interestingly, our viral plaque for-mation also exhibited that infectious viral elements might be securely transmitted to neighboring cells by a secreted exosomal pathway. Taken together, our recent findings emphasize the evidence for a complementary means of CHIKV infection and suggest the role of exosome-mediated CHIKV transmission.

Antivirals against the Chikungunya Virus

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that has re-emerged in recent decades, causing large-scale epidemics in many parts of the world. CHIKV infection leads to a febrile disease known as chikungunya fever (CHIKF), which is characterised by severe joint pain and myalgia. As many patients develop a painful chronic stage and neither antiviral drugs nor vaccines are available, the development of a potent CHIKV inhibiting drug is crucial for CHIKF treatment. A comprehensive summary of current antiviral research and development of small-molecule inhibitor against CHIKV is presented in this review. We highlight different approaches used for the identification of such compounds and further discuss the identification and application of promising viral and host targets.

Musculoskeletal Manifestations Observed in Patients Diagnosed With Chikungunya Virus in 2 Municipalities of the Brazilian Amazon Region

BACKGROUND

Chikungunya virus fever is an emerging disease that is rapidly spreading and becoming a global public health issue because of its clinical manifestations that cause physical limitations and high rates of chronification. No studies have characterized musculoskeletal manifestations in Brazilian patients with chikungunya.

OBJECTIVE

To describe the musculoskeletal manifestations of patients with chikungunya infection in municipalities of the Brazilian Amazon region.

METHODS

This study was an observational, descriptive, and analytical study conducted from March to May 2018. The gender, age, time of infection, clinical manifestations reported during the acute phase, and results of a physical examination of the musculoskeletal system were collected.

RESULTS

The medical records of 63 patients with a laboratory confirmation of chikungunya virus fever were analyzed. Eighty-three percent of these patients were women, with a mean age of 50.6 ± 14.5 years and 3.3 ± 3.1 months of infection. The main clinical manifestations reported during the acute phase were arthralgia (100%), fever (91%), and exanthema (65%). The physical examination revealed that the main joints affected by arthralgia resulted in a polyarticular (57%, 5-10 joints) and symmetrical pattern (62%) that mainly affected the ankles (53%) and knees (51%). Regarding arthritis, the most frequently affected area was the wrist (42%), with an oligoarticular pattern (42%, 2-4 joints).

CONCLUSIONS

In general, the clinical manifestations described in the Brazilian Amazon population are similar to those reported in publications from other countries; however, the main arthritis pattern identified is oligoarticular, with a predominance of the wrist. Moreover, the chronicity rate is 48%.

Identification of 2-(4-(Phenylsulfonyl)piperazine-1-yl)pyrimidine Analogues as Novel Inhibitors of Chikungunya Virus

The chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus, and it is the causative agent of chikungunya fever (CHIKF). Although it has re-emerged as an epidemic threat, so far there are neither vaccines nor pharmacotherapy available to prevent or treat an infection. Herein, we describe the synthesis and structure–activity relationship studies of a class of novel small molecule inhibitors against CHIKV and the discovery of a new potent inhibitor (compound 6a). The starting point of the optimization process was N-ethyl-6-methyl-2-(4-(4-fluorophenylsulfonyl)piperazine-1-yl)pyrimidine-4-amine (1) with an EC₅₀ of 8.68 μM, a CC₅₀ of 122 μM, and therefore a resulting selectivity index (SI) of 14.2. The optimized compound 6a, however, displays a much lower micromolar antiviral activity (EC₅₀ value of 3.95 μM), considerably better cytotoxic liability (CC₅₀ value of 260 μM) and consequently an improved SI of greater than 61. Therefore, we report the identification of a promising novel compound class that has the potential for further development of antiviral drugs against the CHIKV.

Methotrexate an Old Drug with New Tricks

Methotrexate (MTX) is the first line drug for the treatment of a number of rheumatic and non-rheumatic disorders. It is currently used as an anchor disease, modifying anti-rheumatic drug in the treatment of rheumatoid arthritis (RA). Despite the development of numerous new targeted therapies, MTX remains the backbone of RA therapy due to its potent efficacy and tolerability. There has been also a growing interest in the use of MTX in the treatment of chronic viral mediated arthritis. Many viruses-including old world alphaviruses, Parvovirus B19, hepatitis B/C virus, and human immunodeficiency virus-have been associated with arthritogenic diseases and reminiscent of RA. MTX may provide benefits although with the potential risk of attenuating patients' immune surveillance capacities. In this review, we describe the emerging mechanisms of action of MTX as an anti-inflammatory drug and complementing its well-established immunomodulatory activity. The mechanisms involve adenosine signaling modulation, alteration of cytokine networks, generation of reactive oxygen species and HMGB1 alarmin suppression. We also provide a comprehensive understanding of the mechanisms of MTX toxic effects. Lastly, we discussed the efficacy, as well as the safety, of MTX used in the management of viral-related rheumatic syndromes.

Emergence and treatment of chikungunya arthritis

PURPOSE OF REVIEW

To review the emergence, clinical features, pathogenesis, and treatment of acute chikungunya (CHIK) fever and chronic CHIK arthritis.

RECENT FINDINGS

Since 2004, CHIK, an arboviral infection, has spread throughout the world, infecting millions of people. The illness occurs in two phases: an acute viremic infection followed by chronic arthritis. In less developed countries, there are limited resources and effective treatment. For acutely ill CHIK fever patients, management is symptomatic. The treatment of chronic CHIK arthritis should be determined by an understanding of pathogenesis. Is chronic CHIK arthritis a persistent viral infection or a postinfectious inflammatory process? Multiple proinflammatory cytokines, chemokines, and growth factors have been identified in chronic CHIK arthritis. Attempts to isolate CHIK virus from synovial fluid have been unsuccessful. Given pathogenetic similarities (as well as differences) compared with rheumatoid arthritis and the painful, disabling nature of the arthritis, it is not surprising that disease-modifying antirheumatic drugs such as methotrexate have begun to be used.

SUMMARY

CHIK infection has emerged with major arthritic epidemics for which evidence-based therapy is limited. But there is an opportunity to improve the treatment of chronic CHIK arthritis and, from this disease, to gain understanding of the pathogenesis and treatment of inflammatory arthritis more generally.

A Case Report of Chikungunya Fever, Rheumatoid Arthritis, and Felty's Syndrome

INTRODUCTION

Chronic chikungunya (CHIK) arthritis, an inflammatory arthritis, often follows acute CHIK fever (CHIKF), a viral infection. The pathogenesis of chronic CHIK arthritis is poorly characterized, but may resemble other forms of inflammatory arthritis. Clinically, chronic CHIK arthritis sometimes mimics rheumatoid arthritis (RA).

CASE REPORT

We report a patient with well-characterized CHIKF followed 2 months later by chronic CHIK arthritis not only resembling RA clinically, but also associated with RA biomarkers and extra-articular features, including Felty's syndrome (FS).

CONCLUSIONS

We describe this patient's excellent response to methotrexate and discuss the implications her case provides in understanding this important emerging rheumatic disease.