Tshegofatso Mabelane1, Wisdom Basera2, Maresa Botha1, Heidi Facey Thomas1, Jordache Ramjith3,4, Michael E Levin1,5. 1. Department of Paediatric Allergology, University of Cape Town, Cape Town, South Africa. 2. School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. 3. Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa. 4. Department for Health Evidence, Biostatistics Research Group, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands. 5. Invivo Planetary Health, Group of the Worldwide Universities Network (WUN).
Abstract
BACKGROUND: Severe meat allergy with anaphylaxis may be caused by sensitization to alpha-gal. Levels of alpha-gal sensitization that correlate with high risk of meat allergy are currently unknown. We have identified an area with a high prevalence of reported red meat allergy which offered the opportunity to evaluate the diagnostic value of IgE antibody tests. METHODS: To determine levels of alpha-gal IgE and alpha-gal:total IgE ratio in a large cohort of subjects with challenge-proven meat allergy compared with control subjects from the same environment, we conducted fieldwork assessing 131 participants who reported adverse reactions to meat, and 26 control subjects, by questionnaires, IgE sensitization to alpha-gal and oral food challenge to beef sausage. RESULTS: Eighty-four participants were diagnosed with alpha-gal allergy. Alpha-gal IgE ranged between 0.7 and 344.5 kU/L. Alpha-gal:total IgE ratio ranged from 0.1% to 67.6%. Logistic regression analysis showed both alpha-gal IgE and alpha-gal:total IgE ratio strongly correlated with meat allergy, with AUC of 0.95. The values giving the best correct classification were IgE of 2.00 kU/L and ratio of 0.75%. The value above which there is a 95% probability of meat allergy is IgE>5.5 kU/L and ratio of 2.12%. CONCLUSION: Alpha-gal allergy in a population with a high prevalence of reported red meat allergy showed a more rapid onset of symptoms than previously described and a high prevalence of isolated subjective gastrointestinal manifestations. Cutoff values are described for levels of sensitization to alpha-gal IgE and alpha-gal:total IgE ratio that are highly likely to result in clinically significant meat allergy.
BACKGROUND: Severe meat allergy with anaphylaxis may be caused by sensitization to alpha-gal. Levels of alpha-gal sensitization that correlate with high risk of meat allergy are currently unknown. We have identified an area with a high prevalence of reported red meat allergy which offered the opportunity to evaluate the diagnostic value of IgE antibody tests. METHODS: To determine levels of alpha-gal IgE and alpha-gal:total IgE ratio in a large cohort of subjects with challenge-proven meat allergy compared with control subjects from the same environment, we conducted fieldwork assessing 131 participants who reported adverse reactions to meat, and 26 control subjects, by questionnaires, IgE sensitization to alpha-gal and oral food challenge to beef sausage. RESULTS: Eighty-four participants were diagnosed with alpha-gal allergy. Alpha-gal IgE ranged between 0.7 and 344.5 kU/L. Alpha-gal:total IgE ratio ranged from 0.1% to 67.6%. Logistic regression analysis showed both alpha-gal IgE and alpha-gal:total IgE ratio strongly correlated with meat allergy, with AUC of 0.95. The values giving the best correct classification were IgE of 2.00 kU/L and ratio of 0.75%. The value above which there is a 95% probability of meat allergy is IgE>5.5 kU/L and ratio of 2.12%. CONCLUSION: Alpha-gal allergy in a population with a high prevalence of reported red meat allergy showed a more rapid onset of symptoms than previously described and a high prevalence of isolated subjective gastrointestinal manifestations. Cutoff values are described for levels of sensitization to alpha-gal IgE and alpha-gal:total IgE ratio that are highly likely to result in clinically significant meat allergy.
Authors: Jeffrey M Wilson; Alexander J Schuyler; Lisa Workman; Monica Gupta; Hayley R James; Jonathon Posthumus; Emily C McGowan; Scott P Commins; Thomas A E Platts-Mills Journal: J Allergy Clin Immunol Pract Date: 2019-03-30
Authors: Thomas A E Platts-Mills; Scott P Commins; Tilo Biedermann; Marianne van Hage; Michael Levin; Lisa A Beck; Maria Diuk-Wasser; Uta Jappe; Danijela Apostolovic; Michael Minnicozzi; Marshall Plaut; Jeffrey M Wilson Journal: J Allergy Clin Immunol Date: 2020-02-10 Impact factor: 10.793
Authors: Jeffrey M Wilson; Behnam Keshavarz; Hayley R James; Maya K C Retterer; Alexander J Schuyler; Alice Knoedler; Lisa J Workman; Lucy Ng'ang'a; Martha E Chico; Eva Rönmark; Peter W Heymann; Matthew S Perzanowski; Thomas A E Platts-Mills; Philip J Cooper Journal: J Allergy Clin Immunol Date: 2021-02-01 Impact factor: 10.793
Authors: Jeffrey M Wilson; Behnam Keshavarz; Maya Retterer; Lisa J Workman; Alexander J Schuyler; Emily C McGowan; Charles Lane; Alaaddin Kandeel; Jane Purser; Eva Rönmark; Joseph LaRussa; Scott P Commins; Tina Merritt; Thomas A E Platts-Mills Journal: J Allergy Clin Immunol Date: 2020-06-06 Impact factor: 10.793