Nearly half of patients with alpha-gal syndrome experience gastrointestinal symptoms, with women more likely to report GI manifestations, according to a new retrospective study from Mayo Clinic.
The research, which analyzed 124 alpha-gal syndrome (AGS)-positive patients between 2014 and 2023, found that 47% experienced GI symptoms, including diarrhea (32.3%), nausea (31.4%), vomiting (22.6%), and abdominal pain (21.8%). Symptoms usually occur 3 to 6 hours after eating.
The study revealed that patients with AGS were significantly more likely to report tick bites than seronegative controls. They also demonstrated a higher prevalence of urticaria but were less likely to have asthma. Female patients with AGS showed a higher propensity for developing GI symptoms than males.
"A diagnosis of AGS should be strongly considered in patients with a history of tick bites and clinical presentation of allergic or GI manifestations," said lead author Elvira Lesmana, MD, and colleagues in Clinical Gastroenterology and Hepatology. The primary cause is usually the Lone Star Tick in the U.S. However, "globally, other tick species linked to AGS include Ixodes ricinus, Ixodes holocyclus, and Haemaphysalis longicornis," they noted.
For patients who adhered to dietary restrictions, outcomes were promising but varied. Of 40 patients who maintained a red meat-free diet and underwent follow-up, 55% achieved complete symptom resolution, while 35% reported partial improvement. Seven patients successfully reintroduced red meat into their diets without subsequent AGS episodes over an average follow-up period of 27 months.
Strong correlations between alpha-gal IgE levels and meat-specific immunoglobulin E antibodies, particularly in beef, pork, and mutton, were found. "Alpha-gal–containing IgE-binding proteins do not appear to significantly denature on cooking; however, experts have suggested that cooking may reduce reaction severity, possibly by lowering the fat content," they wrote.
The researchers acknowledged study limitations, noting that "a retrospective review of records relies on appropriate physician documentation, and there may have been missing data with regard to the patient's clinical history and laboratory results."
The authors declared having no competing interests.
