Association Between Adenovirus and Severe Blood Clotting Disorder Established by Researchers

A correlation between adenovirus infections and a rare clotting disorder that leads to severe thrombocytopenia has been identified by researchers, thereby broadening our understanding of the factors contributing to this dangerous condition and encouraging further research into its diagnosis and treatment.

Thrombocytes, also known as platelets, are specialized cell fragments that coagulate blood during injuries and abrasions. Their count can be adversely affected by several factors, including viral infections and autoimmune diseases, resulting in a condition termed as thrombocytopenia.

In a comprehensive clinical and scientific collaboration, Dr. Stephan Moll and Dr. Jacquelyn Baskin-Miller, both affiliated with the UNC School of Medicine, have uncovered a relationship between adenovirus infections and a seldom-occurring clotting disorder. This finding is groundbreaking, as it is the first time the virus, usually responsible for mild respiratory symptoms similar to a cold or flu, has been implicated in clotting issues and extreme thrombocytopenia.

Dr. Moll, a professor in the Division of Hematology at the Department of Medicine, indicated that the disorder related to adenovirus is now categorized as one of the four acknowledged anti-PF4 disorders. He expressed hope that this research would facilitate earlier diagnosis and more effective treatment protocols for affected patients.

Published in the New England Journal of Medicine, this new observation illuminates the role of adenovirus in instigating an anti-platelet factor 4 disorder. The revelation paves the way for extensive future research to address remaining questions about the condition’s etiology and those at higher risk of developing it.

HIT, VITT, and “Idiopathic HIT”

Antibodies, which are large Y-shaped proteins, can attach themselves to foreign substances like bacteria, thereby marking them for neutralization or elimination by the immune system.

In cases of anti-PF4 disorders, individuals produce antibodies against platelet factor-4 (PF4), a protein released by platelets. When these antibodies bind to PF4, it can activate a chain reaction leading to rapid platelet depletion and blood clotting.

The condition can sometimes be induced by exposure to heparin, known as heparin-induced thrombocytopenia (HIT), or it may occur spontaneously without such exposure, termed as “idiopathic HIT.”

Over the past three years, a few instances of thrombocytopenia have been observed following inoculation with COVID-19 vaccines that utilize inactivated adenoviral vectors. This phenomenon is identified as vaccine-induced immune thrombotic thrombocytopenia (VITT).

The Path to the Discovery

The research commenced when a 5-year-old outpatient diagnosed with adenovirus had to be hospitalized due to a rapidly developing blood clot in his brain, termed cerebral sinus vein thrombosis, along with severe thrombocytopenia. Medical professionals ascertained that he had not been exposed to either heparin or adenoviral vector-based COVID-19 vaccines.

Collaborative Efforts Crucial for Diagnosis

Dr. Moll consulted with Theodore E. Warkentin, MD, a renowned researcher in anti-PF4 disorders, who was not previously aware of the condition’s association with adenoviral infections. Concurrently, another patient with similar symptoms but no exposure to heparin or vaccines was identified, further underscoring the need for comprehensive research.

Tests confirmed that antibodies in both patients were targeting platelet factor 4, similar to HIT antibodies. They concluded that the patients were suffering from a VITT-like disorder or “idiopathic HIT,” triggered by an adenovirus infection.

Unanswered Questions Remain

Following this groundbreaking discovery, multiple questions concerning the prevalence of the newly identified anti-PF4 disorder, its potential causative factors apart from adenovirus, and effective preventive or therapeutic measures remain to be answered.

Dr. Moll raised pertinent questions about the frequency of the disorder, criteria for testing for anti-PF4 antibodies, and optimal treatment methods to improve the chances of survival for patients afflicted with this potentially fatal condition.

Reference: “Adenovirus-Associated Thrombocytopenia, Thrombosis, and VITT-like Antibodies” by Theodore E. Warkentin, Jacquelyn Baskin-Miller, Alison L. Raybould, Jo-Ann I. Sheppard, Mercy Daka, Ishac Nazy and Stephan Moll, published on 10 August 2023 in the New England Journal of Medicine. DOI: 10.1056/NEJMc2307721.

Frequently Asked Questions (FAQs) about adenovirus and thrombocytopenia

More about adenovirus and thrombocytopenia

• New England Journal of Medicine: Original Research Article
• UNC School of Medicine: Division of Hematology
• Overview of Thrombocytopenia
• Anti-PF4 Disorders: An Overview
• Adenoviruses: General Information
• Platelet Factor-4 (PF4): Biological Functions
• COVID-19 Vaccines and Thrombocytopenia
• Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT)