Which of the following describes the results of saliva neutralization testing where saliva shows a positive reaction with anti-A and negative with anti-B?

In saliva neutralization testing, the results indicate the presence of specific blood group antigens in the saliva. A positive reaction with anti-A means that the saliva contains antigens that can react with anti-A antibodies, indicating the presence of the A antigen. Conversely, a negative reaction with anti-B shows that there are no B antigens present in the saliva.

The result of a positive reaction with anti-A and a negative reaction with anti-B is characteristic of an individual who is a group A secretor. Secretors are those individuals whose saliva contains blood group antigens corresponding to their blood type. Therefore, in this case, the correct interpretation is that the saliva observed reflects the presence of the A antigen, consistent with a type A individual who is capable of secreting their blood group antigen into their saliva.

The confusion may arise from the classification of secretors, as secretors can belong to any of the ABO blood groups. A group O secretor would not show a positive reaction with anti-A; they would, in fact, react negatively in both cases. In other words, salivary tests showing A antigen means the individual must have at least one A allele, while the lack of B antigen indicates they do not possess the B allele, effectively ruling