Valois A, Le Forestier J, Baduel E, Guillot G, Blaise T, et al.
Ticks and tick-borne diseases •
α-Gal Syndrome (AGS) is an IgE-mediated allergy to galactose-α-1,3-galactose (α-Gal), a carbohydrate found in non-primate mammalian tissues. AGS manifests as delayed anaphylactic reactions following the consumption of mammalian meat or exposure to products containing α-Gal. Recent studies confirm tick bites may be a key sensitizing factor. This study aimed to investigate tick bites and other potential risk factors for AGS in French Guiana. A retrospective case-control study was conducted at the Cayenne Hospital Center between January 2021 and October 2022. Cases were defined as adults with clinical symptoms of anaphylaxis after consumption of mammalian meat or α-Gal-containing products, and with detectable anti-α-Gal IgE (> 0.1 kUA/L). Controls were patients consulting for other IgE-mediated allergies, without any symptoms after mammalian meat consumption. Data were collected through a standardized questionnaire and specific IgE assays. Bivariate and multivariate analyses were performed to identify associated risk factors. Confounding biases were limited using a propensity score. A total of 54 patients (18 cases, 36 controls) were included. All AGS cases reported at least one tick bite in French Guiana, versus only 22% of controls (Adjusted OR = 170.250; 95% CI [5.981 - 3.528 × 10^6], p < 0.001). Blood group B or AB was less frequent in cases (0% vs 19%, AOR = 0.227; 95% CI [0 - 8.899], p = 0.488). Atopy was not associated with AGS. In this tropical setting, tick bites, especially from the more anthropophilic Amblyomma cajennense sensu stricto, appear to be a major risk factor for AGS, along with forest-related occupational exposure. These findings support the assumption that ticks are probably at least the main vector of symptomatic sensitization to α-Gal in French Guiana.
This article is a narrative review exploring how research in French Guiana could unlock the mysteries surrounding Alpha-Gal Syndrome (AGS), a recently identified IgE-mediated allergy with delayed reactions to exposure to non-Catarrhine mammalian-derived products. Although fewer than 10 cases have been reported across Latin America, two case series involving 11 and 18 patients with AGS have been documented in French Guiana. This article discusses risk factors such as ethnicity, prior pathogen-induced immunization to α-Gal, vectors responsible for AGS, their environment and ecosystems, observed phenotypes, and therapeutic implications for sensitized individuals. Literature research was based on PubMed between 12/2023 and 08/2024, using: α-Gal/Alpha-1,3-Galactose/galactose-α 1,3-galactose/Red meat allergy/Mammalian meat allergy/Alpha gal syndrome/Antivipmyn. Grey literature from French Guiana were obtained from Prof. Loïc Epelboin. Advancing AGS research in French Guiana could yield valuable epidemiological insights, as existing data predominantly stem from European, North American, Australian, and Japanese contexts - regions with comparatively lower diversity in tick species, their mammalian hosts, associated pathogens, and parasitic infestations. Additionally, French Guiana presents unique therapeutic scenarios, such as Viperidae envenomation and transfusions under inventory constraints, that merit further investigation.
Epelboin L, Roche F, Dueymes M, Guillot G, Duron O, et al.
The American journal of tropical medicine and hygiene •
The past decade has seen the emergence of a new type of food allergy occurring after ingestion of mammalian meat. This allergy is related to immunoglobulin (Ig)E specific for galactose-alpha-1,3 galactose (α-Gal). Originally described in the United States in 2009, other cases have subsequently been described in Australia and in Europe, but still very few in Latin America. The purpose of this study was to show the existence of this pathology in French Guiana and to describe the historical, clinical, and biological characteristics of these patients. Patients reporting an allergy to mammalian meat were included between September 2017 and August 2019. Eleven patients were included, nine of whom exhibited digestive symptoms; four, urticaria reactions; three, respiratory reactions; and five angioedema. The time between ingestion of red meat and reaction varied between 1.5 and 6 hours. The implicated meats were most often beef and pork. All patients had been regularly exposed to tick bites before the appearance of symptoms. All the samples (n = 7) were positive for anti-α-Gal anti-mammalian meats IgE. All the patients were Caucasian French expatriates. This study confirms the presence of this new entity in French Guiana and is the largest reported in Latin America. Our results do not clearly allow us to state that tick bites are the cause of this allergy, but all patients reported being exposed regularly to these arthropods.