ASSOCIATION BETWEEN SECRETOR STATUS AND RESPIRATORY VIRAL ILLNESS

Objective - To determine whether non-secretion of blood group antigens is associated with respiratory virus diseases. Design - Study of secretor status in patients with respiratory virus diseases determined by an enzyme linked immunosorbent assay (ELISA) developed to identify Lewis (Le) blood group antigen phenotypes (Le(a) non-secretor; Le(b) secretor). Subjects - Patients aged 1 month to 90 years in hospital with respiratory virus diseases (584 nasal specimens). Main outcome measures - Criteria for validation of ELISA (congruence between results on ELISA testing of 1155 saliva samples from a previous study and previously established results on haemagglutination inhibition (HAI) testing, proportions of Le(a), Le(b), and Le- phenotypes in 872 samples of nasal washings from a previous study compared with the normal population). Secretor status of patients determined by ELISA and viruses isolated. Results - Agreement between HAI and ELISA for 1155 saliva samples was 97%. Lewis antigens were detected by ELISA in 854 (97.9%) of nasal washings (Le(a) 233 (26.7%), Le(b) 621 (71.2%), and Le- 18 (2.1%)) in proportions predicted for a northern European population. Secretors were significantly overrepresented among patients from whom influenza viruses A and B (55/64, 86%; p < 0.025), rhinoviruses (63/72, 88%; p < 0.01), respiratory syncytial virus (97/109, 89%; p < 0.0005), and echo-viruses (44/44, p < 0.0005) had been isolated compared with the distribution of secretors in the local population. Conclusion - Secretion of blood group antigens is associated with respiratory virus diseases.