Which antibody is suggested by a saline-reactive antibody that is positive with all adult and cord cells but negative on an enzyme panel?

The presence of a saline-reactive antibody that reacts with all adult and cord cells but shows negative results on an enzyme panel strongly suggests the presence of anti-I antibody. This is because anti-I antibodies typically react with adult red cells that possess the I antigen in a saline environment but may not react well with enzyme-treated cells, which can modify the antigens present on the red blood cell surface.

In this scenario, the key characteristics of the antibody's behavior align with anti-I. Anti-I is common in adults and is typically found in high frequency among people who have had certain infections, such as Mycoplasma pneumoniae, which can lead to cold agglutinin disease.

The negative reaction on the enzyme panel indicates that the antibody does not recognize the altered epitopes that enzymes can create, reinforcing the notion that we are dealing with an anti-I antibody instead of other possibilities.

Other antibodies listed, such as anti-i, anti-Gd, and anti-Pr, would exhibit different patterns of reactivity. For instance, anti-i tends to react with cord blood cells more strongly than adult cells, which is contrary to the behavior noted in the question. Anti-Gd and anti-Pr would also show different reactivity characteristics or recognizable patterns not matching those