Differential Diagnosis for Cold Antibody Panel Results

The results of the cold antibody panel are as follows: A1 cells = 0, A2 cells = 2+, B cells = 3+, O adult cells = 4+, Cord O cells = 1+. Based on these results, we can consider the following differential diagnoses:

• Single most likely diagnosis:

  • D. anti-I: This is the most likely diagnosis because the antibody reacts more strongly with adult red blood cells (O adult cells = 4+) than with cord red blood cells (Cord O cells = 1+), which is consistent with the characteristics of anti-I antibodies. Anti-I antibodies typically react more strongly with I antigen, which is more fully expressed on adult red blood cells. The reaction with A2 cells (2+) and B cells (3+) can be explained by the presence of I antigen on these cells as well, although the reaction is generally stronger with O adult cells due to the absence of A or B antigens that might partially mask the I antigen.

• Other Likely diagnoses:

  • A. anti-i: While anti-i is a possibility, it is less likely than anti-I because anti-i typically reacts more strongly with cord red blood cells (which express more i antigen) than with adult red blood cells. However, the given pattern does not strongly support this, as the reaction with cord O cells is significantly weaker than with adult O cells.
  • B. anti-H: Anti-H could potentially react with A2 and B cells due to the H antigen being a precursor to A and B antigens, but the strong reaction with O adult cells and the lack of reaction with A1 cells make this less likely. Anti-H would be expected to react with all cells that express H antigen, including A1 cells.

• Do Not Miss diagnoses:

  • C. anti-IH: Although less common, anti-IH should be considered because it can react with both I and H antigens. However, the pattern of reactivity, especially the strong reaction with O adult cells and the weaker reaction with cord O cells, does not as strongly support anti-IH as it does anti-I. The lack of reaction with A1 cells also makes this less likely, as anti-IH might be expected to react with cells expressing H antigen.

• Rare diagnoses:

  • Other rare cold agglutinins could potentially cause these reaction patterns, but they would be less common and might require additional testing for identification. These could include antibodies against other cold agglutinin antigens or rare specificities that do not fit neatly into the provided categories.