D2.301 - High Prevalence of Familial Meat Allergy on the Black Sea Coast: Insights into Alpha-Gal Syndrome

Alpha-gal syndrome (AGS) is a delayed IgE-mediated allergic reaction to galactose-α-1,3-galactose following the consumption of mammalian meat. This study aimed to characterise the demographic and clinical features of AGS in Ordu, a distinctive region on the Black Sea coast of Turkey characterised by intensive hazelnut agriculture. In this high-risk harvest area, residents experience frequent tick exposure, the primary route of sensitization for AGS.

In this observational study, 128 participants were enrolled, including 88 patients with AGS and 40 age- and sex-matched controls without a history of meat allergy. Demographic variables, clinical characteristics related to meat allergy, comorbid allergic and non allergic conditions, and laboratory findings were evaluated. Statistical analyses were performed using MedCalc software.

The majority of AGS patients were female (71.6%), with a median age of 33 years (IQR: 25–42). No significant differences were observed between patients and controls regarding age, body mass index, or blood group distribution. The median α-gal–specific IgE level among patients was 2.18 kU/L. Symptoms occurred a median of 2.0 hours (IQR: 0.8–4.0) after red meat consumption, and the median age at disease onset was 13 years (IQR: 9–18). Blood group O was the most prevalent among AGS patients (46.5%). Patients with AGS reported a significantly higher frequency of family history of meat allergy compared with controls (47.1% vs. 7.5%, p<0.0001). Additionally, venom allergy (20.5%, p=0.002) and urticaria (28.4%, p=0.01) were significantly more common in the AGS group. In 94.3% of cases, meat allergy preceded the development of venom allergy. Most systemic reactions were classified as moderate (51.1%), followed by severe reactions (31.9%).

AGS in the Ordu region appears to be closely linked to the local agricultural environment. Recurrent tick exposure associated with hazelnut farming may contribute to the high prevalence, early onset, and considerable clinical severity observed in this population. These findings highlight the need for targeted preventive strategies and prospective studies in agricultural regions with high tick exposure.