Duffy a positive

This code indicates the presence of the Duffy a antigen on red blood cells, signifying a specific blood group phenotype. The Duffy blood group system is one of several systems used in blood typing, and the 'a' antigen is a common variant within this system. Its presence or absence can be clinically significant in transfusion medicine and in certain disease states.

This code is used when laboratory testing confirms that a patient is positive for the Duffy a antigen. This information is often documented during pre-transfusion testing, in cases of hemolytic disease of the newborn, or when investigating transfusion reactions. It may also be relevant in genetic studies or for patients with specific hematological conditions.

• Ensure documentation clearly states "Duffy a positive" based on laboratory results.
• Do not use this code for other Duffy phenotypes (e.g., Duffy b positive, Duffy negative).
• This code is typically used as a secondary diagnosis to provide additional clinical detail, not as a primary reason for encounter.