CPT® Code 81268

Chimerism (engraftment) analysis, post transplantation specimen (eg, hematopoietic stem cell), includes comparison to previously performed baseline analyses; with cell selection (eg, CD3, CD33), each cell type

Molecular genetic testing, specifically chimerism analysis, is a critical procedure performed to assess the extent of chimerism following hematopoietic stem cell transplantation. This analysis is essential for monitoring the success of the transplant and determining the proportion of donor versus recipient cells in the patient's body. The procedure involves the preparation of specific cell populations, namely CD3+ and CD33+ cells, which are isolated using monoclonal antibody-coupled magnetic beads. Once isolated, these cells are lysed to release their genetic material for further analysis. The engraftment testing is conducted through gene amplification techniques that target variable number tandem repeat (VNTR) or short tandem repeat (STR) loci, which are specific regions of DNA that can vary between individuals. The testing process is divided into three distinct parts: initially, a pre-transplant analysis is performed to establish a baseline by identifying the loci that will be used to differentiate between the recipient's and donor's alleles. Following this, a post-transplant sample is collected and separated into the CD3+ and CD33+ fractions. Finally, a post-transplant analysis is conducted to quantify the presence of recipient and donor DNA in various biological samples, such as blood, bone marrow, or other tissues. It is important to report CPT® Code 81268 for each cell type analyzed, ensuring accurate documentation and billing for the services rendered.