CPT® Code 86826

Add-On Code

Human leukocyte antigen (HLA) crossmatch, non-cytotoxic (eg, using flow cytometry); each additional serum sample or sample dilution (List separately in addition to primary procedure)

Human leukocyte antigens (HLA) are specific protein molecules located on the surface of most body cells, playing a crucial role in the immune system's ability to recognize foreign cells. These antigens are vital for determining compatibility in organ and tissue transplant procedures. In the context of transplantation, the presence of certain HLA markers can significantly influence the success of the procedure. While there are numerous HLA molecules, only a select few—typically six—are assessed during transplant crossmatch procedures to ensure compatibility between the donor and recipient. The process begins with typing the HLAs, which involves identifying the specific HLA markers present in both the recipient and the donor. This typing is conducted as a separate procedure prior to the crossmatch. Ideally, the donor and recipient will share identical HLA markers; however, if discrepancies exist, transplantation may still be feasible if the recipient has not developed antibodies against the donor's HLA markers. The presence of such antibodies can lead to an immune response that attacks the transplanted cells, tissue, or organ. To perform the crossmatch, blood samples are collected from both the donor and recipient. The donor's cells are then combined with the recipient's serum, and the mixture is analyzed for reactions using a non-cytotoxic method, such as flow cytometry. A negative reaction indicates compatibility, suggesting that the recipient does not possess antibodies against the donor's HLA, thereby allowing the transplant to proceed. Conversely, a positive reaction signifies the presence of antibodies, indicating that transplantation is not advisable. For billing purposes, CPT® Code 86825 is used for the first serum sample or dilution, while CPT® Code 86826 is designated for each additional serum sample or sample dilution.