The mechanistic basis of protection by non-neutralizing anti-alphavirus antibodies

Although neutralizing monoclonal antibodies (mAbs) against epitopes within the alphavirus E2 protein can protect against infection, the functional significance of non-neutralizing mAbs is poorly understood. Here, we evaluate the activity of 13 non-neutralizing mAbs against Mayaro virus (MAYV), an emerging arthritogenic alphavirus. These mAbs bind to the MAYV virion and surface of infected cells but fail to neutralize infection in cell culture. Mapping studies identify six mAb binding groups that localize to discrete epitopes within or adjacent to the A domain of the E2 glycoprotein. Remarkably, passive transfer of non-neutralizing mAbs protects against MAYV infection and disease in mice, and their efficacy requires Fc effector functions. Monocytes mediate the protection of non-neutralizing mAbs in vivo, as Fcγ-receptor-expressing myeloid cells facilitate the binding, uptake, and clearance of MAYV without antibody-dependent enhancement of infection. Humoral protection against alphaviruses likely reflects contributions from non-neutralizing antibodies through Fc-dependent mechanisms that accelerate viral clearance.

A cross-reactive antibody protects against Ross River virus musculoskeletal disease despite rapid neutralization escape in mice

Arthritogenic alphaviruses cause debilitating musculoskeletal disease and historically have circulated in distinct regions. With the global spread of chikungunya virus (CHIKV), there now is more geographic overlap, which could result in heterologous immunity affecting natural infection or vaccination. Here, we evaluated the capacity of a cross-reactive anti-CHIKV monoclonal antibody (CHK-265) to protect against disease caused by the distantly related alphavirus, Ross River virus (RRV). Although CHK-265 only moderately neutralizes RRV infection in cell culture, it limited clinical disease in mice independently of Fc effector function activity. Despite this protective phenotype, RRV escaped from CHK-265 neutralization in vivo, with resistant variants retaining pathogenic potential. Near the inoculation site, CHK-265 reduced viral burden in a type I interferon signaling-dependent manner and limited immune cell infiltration into musculoskeletal tissue. In a parallel set of experiments, purified human CHIKV immune IgG also weakly neutralized RRV, yet when transferred to mice, resulted in improved clinical outcome during RRV infection despite the emergence of resistant viruses. Overall, this study suggests that weakly cross-neutralizing antibodies can protect against heterologous alphavirus disease, even if neutralization escape occurs, through an early viral control program that tempers inflammation.

The induction of broadly neutralizing antibodies is a goal of many antiviral vaccine programs. In this study, we show that cross-reactive monoclonal and polyclonal antibodies developed after CHIKV infection or immunization with relatively weak cross-neutralizing activity can protect against RRV-induced musculoskeletal disease in mice. Even though RRV rapidly escaped from neutralization, antibody therapy reduced inflammation in musculoskeletal tissues and decreased viral burden near the site of infection in a manner that required type I interferon signaling. These studies in mice show that broadly reactive antibodies with limited neutralizing activity still can confer protection against heterologous alphaviruses.

Treatment of chikungunya musculoskeletal disorders: a systematic review

INTRODUCTION

Chikungunya virus is amongst the fastest expanding vector transmissible diseases in recent years and has been causing massive epidemics in Africa, Asia, Latin America and the Caribbean. Despite human infection by this virus being first described in the 1950s, there is a lack of adequate therapeutic evaluations to guide evidence-based recommendations. The current guidelines rely heavily in specialists' opinion and experience instead of using higher rated evidence. Areas covered: A systematic review of the literature was performed- not restricted to clinical trials - reporting the therapeutic response against this infection with the intent to gather the best evidence of the treatment options against musculoskeletal disorders following chikungunya fever. The 15 studies included in the analysis were categorized considering the initiation of treatment during the acute, subacute and chronic phase. Expert commentary: This review demonstrates the complexity of chikungunya fever and difficulty of therapeutic management. This review found no current evidence-based treatment recommendations for the musculoskeletal disorders following chikungunya fever. To provide an optimal treatment that prevents perpetuation or progression of chikungunya infection to a potentially destructive and permanent condition without causing more harm is an aim that must be pursued by researchers and health professionals working with this disease.

Characteristics of the musculoskeletal symptoms observed among survivors of Ebola virus disease in the Postebogui cohort in Guinea

Objective

Previous studies show that arthralgia is the most common symptom experienced by Ebola virus disease (EVD) survivors. Nevertheless, specific analyses of rheumatological sequelea are still lacking.

Methods

The Postebogui study is a prospective, multicentre cohort aiming to evaluate the long-term outcomes of EVD survivors infected during the 2014-15 outbreak in Guinea. Of the 216 participants enrolled in the study in October 2015, 44 patients with arthralgia/myalgia underwent a physical examination by a rheumatologist (the Eborheum cohort). Data were collected using a standardized questionnaire.

Results

In the Eborheum cohort, 61% of patients were female, the median age was 31.1 years, and the median time from Ebola Treatment Centre discharge was 8.8 months. Pain manifestation started after Ebola infection in all but one patient. Patients had mainly both mechanical and inflammatory pain (45%) and low back pain (77%). All patients reported pain in at least one peripheral joint. Pain in large joints was more frequently reported than in small joints (73 vs 41%). Oligo- and polyarticular presentations were similar, with symmetrical pain distribution. Furthermore, 36 patients had at least one painful 18-tender point count, most of whom reported extensive pain (n = 19) and symmetrical distribution (91%). Diagnoses were mainly non-specific musculoskeletal disorders (59%) and mechanical back pain (52%). No polyarthritis was observed. We found a higher percentage of depressed patients compared with the remaining Postebogui group (42 vs 11%; P < 0.001).

Conclusion

Results from the study come from the first complete rheumatological examination of a cohort of EVD survivors, nearly 9 months after Ebola Treatment Centre discharge. Importantly, we found that patients with arthralgia/myalgia included in the Eborheum cohort were more likely to experience depression than survivors not reporting these symptoms, highlighting the impact of pain symptoms among survivors.

Perosomus elumbis in a Holstein calf infected with bovine viral diarrhea virus

The detection of bovine viral diarrhea virus (BVDV) in a female Holstein calf presented with perosomus elumbis, a congenital anomaly, is reported here. A cow with dystocia was evaluated and an abnormal dead calf was detected during vaginal examination. The calf was retrieved via caesarean section and exhibited abnormalities characteristic of PE, such as vertebral and pelvic malformations. These abnormalities were further confirmed using radiographic and necropsy examinations. At necropsy cerebellar hypoplasia was an additional finding, which is a typical lesion associated with bovine virus diarrhea (BVD). Several tissue samples from the calf were tested for the presence of antigens of BVDV and bovine herpesvirus-1 (BHV-1) by ELISA. In addition, sera samples from the dam and calf were tested for the presence of antibodies against BVDV, BHV-1, and bluetongue disease virus (BTV) using a virus neutralization assay. Results indicated that the calf was congenitally infected with BVDV, whereas there was no evidence for the presence of BHV-1 and BTV. In the dam's serum no antibodies against BVDV, BHV-1, and BTV were detected. Even though the etiology of perosomus elumbis is unknown, BVDV, which causes fetal anomalies at early gestation in cows, may have been a contributing factor in this case.

Musculoskeletal and joint manifestations in human immunodeficiency virus positive patients

With the increase in the number of human immunodeficiency virus positive patients, more and more patients are referred with musculoskeletal or joint manifestations. It is important to differentiate between various causes resulting in musculoskeletal or joint manifestations. In this prospective study 30 patients out of 569 human immune deficiency virus positive patients presented with musculoskeletal or joint manifestations (incidence being 5.27%), simple arthralgia was the most common manifestation in 16 patients. Reactive arthritis was diagnosed in 6 patients and infective arthritis in 5 patients. After the treatment 16 patients had complete recovery, 9 patients had partial recovery and 3 patients had no recovery of joint manifestation. One patient expired due to septicaemia and another lost to follow-up.

Human cytomegalovirus-associated oral and maxillo-facial disease

Human cytomegalovirus is a ubiquitous pathogen with protean clinical manifestations. After initial infection, the virus remains in a persistent state in the host. Immunity plays a pivotal role in counteracting its virulence, albeit intermittent virus shedding occurs in immunocompetent individuals. Should deficiencies in immunity occur, e.g., as a consequence of AIDS or iatrogenic immunosuppression, then virus replication and subsequent pathogenic manifestations ensue. In the oral and maxillo-facial region, the virus causes a wide variety of diseases, mainly atypical chronic ulcerations and sialadenitis. These morbidities are rarely reported and sometimes cause significant problems for clinicians.

Musculoskeletal disorders associated with HIV infection and AIDS. Part II: non-infectious musculoskeletal conditions

This section of a two-part series on musculoskeletal disorders associated with HIV infection and AIDS reviews the non-infectious musculoskeletal conditions. In the first part, the infectious conditions were reviewed. The non-infectious conditions include polymyositis, drug-induced myopathy, myositis ossificans, adhesive capsulitis, avascular necrosis, bone marrow abnormalities, and hypertrophic osteoarthropathy. Inflammatory and reactive arthropathies are more prevalent in HIV-positive individuals, and a separate section is dedicated to these conditions, including Reiter's syndrome, psoriatic arthritis, HIV-associated arthritis, painful articular syndrome, and acute symmetric polyarthritis. Lastly, we include a discussion of HIV-related neoplastic processes that affect the musculoskeletal system, namely Kaposi's sarcoma and non-Hodgkin's lymphoma.

HIV-associated musculoskeletal involvement

Various rheumatic manifestations associated with HIV infection have been recognized, ranging from infectious conditions, such as septic arthritis, to seronegative spondyloarthropathy. Other musculoskeletal manifestations include lupus-like and Sjögren-like diseases and HIV-related malignancy. The introduction of HAART has changed the spectrum of the clinical manifestations of rheumatic disease seen today, with infections and articular involvement being the most frequently observed.

Musculoskeletal manifestations and autoantibody profile in 90 hepatitis C virus infected Israeli patients

OBJECTIVES

Recent interest has been expressed in rheumatic manifestations in hepatitis C virus (HCV)-infected populations. The aim of this study was to determine the prevalence and characteristics of the musculoskeletal manifestations and serological markers of autoimmunity in HCV-infected patients in Israel.

METHODS

Ninety anti-HCV-positive patients were consecutively interviewed and examined. The prevalence of autoantibodies and their association with rheumatologic symptoms were also determined.

RESULTS

Rheumatic manifestations were found in 28 subjects (31%), and included arthralgias (9%), arthritis (4%), cryoglobulinemia (11%), sicca symptoms (8%), cutaneous vasculitis (2%), polymyositis (1%), and antiphospholipid syndrome (1%). Rheumatic complications were not associated with liver disease severity, or subjects' gender. In addition, myalgia was reported by 22 patients (24%), and fibromyalgia was diagnosed in 14 (16%). Sixty-nine percent of the patients had at least one autoantibody detected in their serum, the most prevalent being rheumatoid factor (RF), 44%; antinuclear antibody (ANA), 38%; and IgM and IgG anticardiolipin antibodies (ac1), 28% and 22%, respectively. The frequency of autoantibodies was not associated with liver disease severity or rheumatic disorders.

CONCLUSIONS

Musculoskeletal manifestations and autoimmune markers are common in HCV infection. An investigation of risk factors for HCV infection is pertinent in a patient presenting new rheumatic manifestations and should be included in the history of present illness. Future studies of these disorders may uncover the full spectrum of these associations and provide new insights into their operating mechanisms.

HIV infection-associated inflammatory musculoskeletal disorders

Inflammatory musculoskeletal complaints are relatively common during the course of HIV infection, although they tend to be more frequent during late stages. The clinical spectrum is varied, ranging from arthralgias to distinct rheumatic disorders, such as Reiter's syndrome and psoriatic arthritis. The therapeutic management often poses a challenge, although most patients respond to conventional first- and second-line anti-inflammatory medications.