The Monocyte Monolayer Assay: Past, Present and Future

Area of Science:

• Transfusion Medicine
• Immunology
• Hematology

Background:

• Serologic testing, such as the indirect antiglobulin test (IAT), has limitations in assessing the clinical significance of red blood cell (RBC) antibodies, especially those targeting high-prevalence antigens.
• The monocyte monolayer assay (MMA) is a functional cellular assay studied for over 40 years to differentiate clinically significant from insignificant RBC antibodies.

Purpose of the Study:

• To review the history, optimization, and current applications of the MMA in transfusion medicine.
• To highlight the MMA's potential in selecting donor blood for patients with serologically incompatible crossmatches.
• To discuss ongoing efforts to improve and validate the MMA's efficacy.

Main Methods:

• Review of historical data and recent clinical applications of the MMA.
• Description of MMA optimization strategies.
• Discussion of ongoing research for efficacy documentation.

Main Results:

• The MMA has been successfully used to select donor blood for transfusions in patients with serologically incompatible crossmatches, without adverse events.
• The MMA demonstrates potential for managing complex alloantibody situations and antibodies to high-prevalence antigens.

Conclusions:

• The MMA is a valuable tool for determining the clinical significance of RBC antibodies, aiding in transfusion decisions.
• Further research and optimization are needed to enhance the MMA's efficacy and facilitate its routine laboratory use.