Common Cold Virus and Blood Clotting Disorder

Viral infections, autoimmune disease, and other conditions can cause platelet levels to drop throughout the body, termed thrombocytopenia.

After a robust clinical and research collaboration, Stephan Moll, MD, and Jacquelyn Baskin-Miller, MD, both in the UNC School of Medicine, have linked adenovirus infection with a rare blood clotting disorder. 

This is the first time that the common respiratory virus, which causes mild cold-and flu-like symptoms, has been reported to be associated with blood clots and severe thrombocytopenia.

Their new observation, which was published in the New England Journal of Medicine, sheds new light on the virus and its role in causing an anti-platelet factor 4 disorder. Additionally, the discovery opens a whole new door for research, as many questions remain as to how and why this condition occurs — and who is most likely to develop the disorder.

In the last three years, thrombocytopenia has been shown to rarely occur after injection with COVID-19 vaccines that are made with inactivated pieces of an adeno-viral vector. The condition is referred to as vaccine-induced immune thrombotic thrombocytopenia (VITT).

The road to the discovery started when a 5-year-old boy who had been diagnosed as an outpatient with adeno virus infection had to be admitted to the hospital with an aggressive blood clot forming in his brain (called cerebral sinus vein thrombosis) and severe thrombocytopenia. It looked like the pediatric patient could have “spontaneous HIT.” 

Alison L. Raybould, MD, a hematologist-oncologist in Richmond, Virginia, a previous trainee from UNC. Was seeing a patient who had multiple blood clots, a stroke and heart attack, arm and leg deep-vein thromboses (DVT), and severe thrombocytopenia.

The patient had not been exposed to heparin or vaccines. However, this patient’s severe illness had also started with viral symptoms of cough and fever, and she had tested positive for adenoviral infection. Testing for an anti-PF4 antibody also turned out to be positive.

To help clarify the diagnoses of the two patients, Warkentin immediately offered to further test the patients’ blood and samples were directly to his laboratory in the Hamilton General Hospital for further study. They confirmed that the antibodies were targeting platelet factor 4, much like the HIT antibodies.

Surprisingly, the antibody resembled that of the VITT and bound to PF4 in the same region as VITT antibodies do. They concluded that both the patients had “spontaneous HIT” or a VITT-like disorder, associated with an adenovirus infection.

Moll and colleagues are now left with many questions about the prevalence of the new anti-PF4 disorder, whether the condition can be caused by other viruses, and why this condition doesn’t occur with every infection with adenovirus.

They also wonder what preventative or treatment measures can be made to help patients who develop the new, potentially deadly anti-PF4 disorder.

Sources:

Theodore E. Warkentin, Jacquelyn Baskin-Miller, Alison L. Raybould, Jo-Ann I. Sheppard, Mercy Daka, Ishac Nazy, Stephan Moll. Adenovirus-Associated Thrombocytopenia, Thrombosis, and VITT-like Antibodies. New England Journal of Medicine, 2023; 389 (6): 574 DOI: 10.1056/NEJMc2307721

University of North Carolina Health Care. (2023, August 10). Common cold virus linked to potentially fatal blood clotting disorder. ScienceDaily. Retrieved August 10, 2023 from www.sciencedaily.com/releases/2023/08/230810110315.htm
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