What can be a result of cold agglutinins in blood tests?

Cold agglutinins are antibodies that clump red blood cells in response to cold temperatures, usually associated with certain infections, such as Mycoplasma pneumoniae. When blood samples containing cold agglutinins are analyzed at lower temperatures, the clumping can cause an increase in the appearance of red blood cells, which may lead to a false positive result in tests that measure the concentration of these cells.

In the context of blood tests, these agglutinins can interfere with various measurements and can create the impression that a different condition than what is actually present is occurring. This Misinterpretation due to cold agglutinins can lead to incorrect conclusions regarding a patient's hematological status or underlying health issues, emphasizing the need for sample handling at appropriate temperatures to ensure accurate results.

Issues such as false negative reactions, inaccurate blood typing, or false hematocrit levels can also occur in the presence of cold agglutinins; however, the direct impact on assay outcomes is predominantly reflected in false positive results due to the agglutination effect. Therefore, recognizing the potential for false positives is crucial when interpreting laboratory results, especially in a clinical setting where timing and temperature of sample processing are significant.