In an antibody screen where a suspected rouleaux reaction is tested with saline replacement and the reaction remains, what is the best interpretation?

In the context of blood banking, when conducting an antibody screen, the presence of a suspected rouleaux reaction indicates that red blood cells are stacking together due to plasma protein abnormalities rather than true agglutination due to antibodies binding to antigens on the surface of red blood cells.

When a saline replacement is performed to differentiate between rouleaux and true agglutination, the expectation is that if the reaction still persists after saline is added, it suggests that the initial aggregation was not simply due to the presence of excess proteins causing rouleaux. Instead, it confirms that true immunological agglutination is occurring, meaning that antibodies are actually binding to their corresponding antigens on the red blood cells, leading to agglutination.

The presence of a continued reaction post-saline replacement indicates that the original reaction was indeed due to true agglutination rather than a false positive attributable to rouleaux. This interpretation is crucial for proper identification and management of potential blood group antibodies in patients.

In contrast, the alternative interpretations, such as confirming rouleaux or stating that the test is invalid, would not align with the results observed after the saline replacement, showing that the best conclusion in this case is that true agglutination is responsible