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Researchers at the UNC Institute for Global Health and Infectious Diseases and the Thurston Arthritis Research Center’s Core Center for Clinical Research, investigated the relationship between knee pain and a red meat allergy, caused by a tick bite known as alpha-gal syndrome. “Tick-borne disease infections and chronic musculoskeletal pain,” published in JAMA Network Open, is believed to be the largest population-based seroprevalence study of alpha-gal in the U.S. 

Zychowski-Diana-tick-borne-knee-pain-study“In clinic we sometimes see patients that attribute nonspecific symptoms, such as muscle or joint pains, to prior tick-borne disease,” said lead author Diana Zychowski, MD, MPH, third year fellow in the division of infectious diseases. “While there is a physiological basis for prior tick bites and joint pain (ie. lyme disease and the development of arthritis), infections caused by Ehrlichia and Rickettsia generally do not cause chronic infections and most individuals recover fully. While some individuals may present with overt allergic symptoms, there may be more subtle manifestations of alpha-gal syndrome such as chronic joint pains.” 

The study leveraged an established longitudinal cohort, the Johnston County Osteoarthritis Project (JoCo OA), to evaluate associations between prior exposure to tick-borne diseases and musculoskeletal symptoms, including osteoarthritis. 

Using a multi-disciplinary approach to analyze radiographic osteoarthritis, questionnaires, physical assessments, and biospecimens, the team asked whether tick-borne diseases were associated with chronic musculoskeletal symptoms. The study found a high prevalence of tick-borne disease exposure in the Johnston County, NC population, as well as a high frequency of alpha-gal IgE positivity.

“High prevalence rates for Ehrlichia (~9%), Rickettsia (~17%) and Alpha-gal (20%) suggested frequent human-tick interactions. But antibodies to these tick-borne diseases were not associated with osteoarthritis. And prior exposure to Ehrlichia and Rickettsia was not associated with musculoskeletal pains, though those with positive alpha-gal serology were more likely to report knee pain, aching, or stiffness. We also learned that females who recalled a tick bite in the past five years, and females who are current smokers, were more likely to have a positive alpha-gal serology.”

Zychowski says it was reassuring to find no association between chronic musculoskeletal pains and osteoarthritis for those who were previously exposed to Ehrlichia and Rickettsia; however, there is more to learn about alpha-gal syndrome.

“For example, what are the symptoms might patients experience, and what risk factors lead to chronic disease, because not everyone with positive serology is symptomatic. As the climate changes and ticks expand their geographical range, we need ongoing surveillance to identify these emerging pathogens, identify those at risk, and target prevention efforts.”

The collaboration included the division of allergy and immunology, the Carolina Population Center and Gillings School of Global Public Health. Statistical support from the UNC Core Center for Clinical Research (CCCR) was leveraged for this study.

Other investigators included: Haley Abernathy; Dana Giandomenico, MPH; Ross Boyce, MD, MSc; Carolina Alvarez, MS; Shailesh Choudhary, PhD; Julia Vorobiov; Amanda Nelson, MD, MSCR; and Scott Commins, MD, PhD.

Click here to read the full article available on the JAMA Network website.Study