Specific autoantibodies to platelet glycoproteins in Epstein-Barr virus-associated immune thrombocytopenia

Herpesvirus Infection of Endothelial Cells as a Systemic Pathological Axis in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Understanding the pathophysiology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is critical for advancing treatment options. This review explores the novel hypothesis that a herpesvirus infection of endothelial cells (ECs) may underlie ME/CFS symptomatology. We review evidence linking herpesviruses to persistent EC infection and the implications for endothelial dysfunction, encompassing blood flow regulation, coagulation, and cognitive impairment-symptoms consistent with ME/CFS and Long COVID. This paper provides a synthesis of current research on herpesvirus latency and reactivation, detailing the impact on ECs and subsequent systemic complications, including latent modulation and long-term maladaptation. We suggest that the chronicity of ME/CFS symptoms and the multisystemic nature of the disease may be partly attributable to herpesvirus-induced endothelial maladaptation. Our conclusions underscore the necessity for further investigation into the prevalence and load of herpesvirus infection within the ECs of ME/CFS patients. This review offers conceptual advances by proposing an endothelial infection model as a systemic mechanism contributing to ME/CFS, steering future research toward potentially unexplored avenues in understanding and treating this complex syndrome.

Prevalence of Cytomegalovirus (CMV) and Epstein-Barr Virus (EBV) Subclinical Infection in Patients with Acute Immune Thrombocytopenic Purpura (ITP)

Background: Immune thrombocytopenic purpura (ITP) defined as a bleeding disorder in which the number and production of platelets reduced by the immune system; however, the destruction of peripheral blood platelets also occurs. Although its exact etiology and pathogenesis not already know, several studies have shown that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) known as possible causative agents of ITP. This investigation aims to evaluate the presence of CMV and EBV in two groups of case and control by polymerase chain reaction (PCR).

Materials and Methods: we considered the presence of CMV and EBV in 48 acute ITP patients and 48 healthy people. Study participants were recruited from Ahvaz Shafa Hospital between 2017 and 2018 and the presence of two viruses was investigated by (PCR).

Results: Out of 48 acute ITP patients, the CMV DNA was detected from the blood of 12 (25%) patients and the EBV DNA from the blood of 2 (4.2%) other patients. In addition, only one patient was (2.1%) co-infected with CMV and EBV. In contrast, in 48 healthy subjects, 3 (6.6%) had CMV and none of the control group was infected with EBV.

Conclusion: Due to the presence of both EBV and CMV in the acute ITP patients in Ahvaz, they can be considered as factors in the progression of this disease. Therefore, consideration of the methods of elimination and treatment of these two viruses in these patients may be used as a treatment strategy in ITP patients in the future.

Long-term Successful Treatment of Rituximab for Steroid-resistant Minimal Change Nephrotic Syndrome and Idiopathic Thrombocytopenic Purpura

A 22-year-old woman had been diagnosed with idiopathic thrombocytopenic purpura (ITP) 5 years earlier. After undergoing splenectomy, she relapsed frequently following prednisolone tapering. She was complicated with minimal change nephrotic syndrome (MCNS) while taking 20 mg of prednisolone. Despite treatment with prednisolone, cyclosporin and low-density lipoprotein-apheresis, MCNS and ITP did not improve. We added rituximab in 4 weekly infusions of 375 mg/m2. MCNS and ITP were in complete remission. After administering rituximab once, all medicines were discontinued. No relapse had occurred by 50 months following the first rituximab administration. Rituximab affects steroid-resistant MCNS and ITP for a long time without complications.

Severe thrombocytopenia and recurrent epistaxis associated with primary Epstein-Barr virus infection

Infectious mononucleosis, caused by the Epstein-Barr virus (EBV), generally follows a benign, yet protracted course, with the majority of symptoms being systemic somatic symptoms. Rarely, the clinical picture can be complicated by more acute severe haemotological sequelae of the disease, requiring hospitalisation and causing diagnostic uncertainty, particularly when distinguishing between a viral illness and a lymphoproliferative disorder. We describe the case of a young male patient who presented with headache, recurrent epistaxis and severe thrombocytopenia.

In vitro detection of hepatitis C virus in platelets from uninfected individuals exposed to the virus

INTRODUCTION

Despite hepatocytes being the target cells of hepatitis C virus (HCV), viral ribonucleic acid RNA has been detected in other cells, including platelets, which have been described as carriers of the virus in the circulation of infected patients. Platelets do not express cluster differentiation 81 CD81, the main receptor for the virus in hepatocytes, although this receptor protein has been found in megakaryocytes. Still, it is not clear if HCV interacts with platelets directly or if this interaction is a consequence of its association with megakaryocytes. The aim of this study was to evaluate the interaction of HCV with platelets from non-infected individuals, after in vitro exposure to the virus.

METHODS

Platelets obtained from 50 blood donors not infected by HCV were incubated in vitro at 37°C for 48h with serum containing 100,000IU∕mL of genotype 1 HCV. After incubation, RNA extracted from the platelets was assayed for the presence of HCV by reverse transcription – polymerase chain reaction RT-PCR.

RESULTS

After incubation in the presence of virus, all samples of platelets showed HCV RNA.

CONCLUSIONS

The results demonstrate that, in vitro, the virus interacts with platelets despite the absence of the receptor CD81, suggesting that other molecules could be involved in this association.

Review: Viral infections and mechanisms of thrombosis and bleeding

Viral infections are associated with coagulation disorders. All aspects of the coagulation cascade, primary hemostasis, coagulation, and fibrinolysis, can be affected. As a consequence, thrombosis and disseminated intravascular coagulation, hemorrhage, or both, may occur. Investigation of coagulation disorders as a consequence of different viral infections have not been performed uniformly. Common pathways are therefore not fully elucidated. In many severe viral infections there is no treatment other than supportive measures. A better understanding of the pathophysiology behind the association of viral infections and coagulation disorders is crucial for developing therapeutic strategies. This is of special importance in case of severe complications, such as those seen in hemorrhagic viral infections, the incidence of which is increasing worldwide. To date, only a few promising targets have been discovered, meaning the implementation in a clinical context is still hampered. This review discusses non‐hemorrhagic and hemorrhagic viruses for which sufficient data on the association with hemostasis and related clinical features is available. This will enable clinicians to interpret research data and place them into a perspective. J. Med. Virol. 84:1680–1696, 2012. © 2012 Wiley Periodicals, Inc.

Gammaherpesvirus latency induces antibody-associated thrombocytopenia in mice

Human herpesviruses establish lifelong latency. Viral recrudescence can lead to the development of cancers, immunoproliferative disorders, transplantation complications, and thrombocytopenia. Although platelet-specific autoantibodies have been reported in patients infected with the Epstein-Barr virus (EBV), the mechanisms by which thrombocytopenia is induced remain unclear, as do the relative contributions of lytic viral replication and latent viral gene expression. The human gammaherpesviruses are tightly restricted in their ability to infect other mammals, so they are difficult to study in live animal models. Here we show that infection of mice with murine gammaherpesvirus-68 (γHV68), a rodent-specific pathogen closely related to EBV, induces the production of platelet-binding antibodies and causes thrombocytopenia. Infection of antibody-deficient mice does not lead to thrombocytopenia, indicating the platelet decrease is mediated by antibody. Additionally, infection with a latency-null recombinant γHV68 does not induce thrombocytopenia, suggesting factors associated with viral latency drive the infection-induced antibody-mediated thrombocytopenia. These studies describe an important animal model of gammaherpesvirus-induced autoimmune thrombocytopenia and demonstrate that this pathology is mediated by antibody and dependent on viral latency. This model will allow studies of the underlying mechanisms of disease progression and the testing of therapeutic strategies for the alleviation of virus-induced thrombocytopenia.

[Infectious mononucleosis and severe thrombocytopenia]

Infectious mononucleosis by Epstein-Barr virus is usually a benign self-limiting disease. We present two cases admitted in the same week, with suspected co-infection by other viruses (cytomegalovirus and human herpes virus 6), which showed severe thrombocytopenia in the acute phase of the disease. The progress and treatment were different in each case.

Human metapneumovirus infection in an immunocompetent adult presenting as mononucleosis-like illness

A 37-year-old man was presented with incidental findings of neutropenia, atypical lymphocytosis, thrombocytopenia and deranged liver parenchymal enzymes. Four days later, he developed fever, sore throat and cervical lymphadenopathy, compatible with mononucleosis-like illness (MLI). Polymerase chain reaction (PCR) and viral culture of the nasopharyngeal swab showed human metapneumovirus (hMPV). There was a >/=4-fold rise in IgG against hMPV. This is the first case report illustrating the natural clinical course of hMPV-related MLI.