Crossmatch

HLA & Transplant | Crossmatch

The crossmtach (XM) is performed to determine the safety of moving forward with transplantation when the recipient has donor specific HLA antibodies (DSA). The HLA antibodies that react with the donor's HLA antigens leading to a positive crossmatch can be produced due to previous sensitization events such as previous transplant, blood transfusion or pregnancy. The positive crossmatch suggests that there is a risk of antibody-mediated rejection (AMR) if the transplant proceeds.

The crossmatch may be performed using various methods. The flow cytometric crossmatch (FCXM) is a sensitive method and provides best estimate of a patient’s risk for AMR. The FCXM is performed by incubating donor lymphocytes, recipient serum, and a fluorescent labelled anti-human immunoglobulin together and running them through a flow cytometer. The level of fluorescence is proportional to the amount of antibody bound to the cell. Markers with different fluorochromes are also added to separate T and B cell reactivity allowing for T and B cell crossmatch results obtained in the same run. pre-transplant T- and B-cell FCXM results have been associated with allograft outcomes. HLA class I antigens are expressed on T cells and B cells, and studies suggest that the cell surface expression of HLA class I antigens is higher on B than on T cells. Thus, a T-cell-positive, B-cell-positive (T+B+) FCXM, rather than a T-cell-positive, B-cell-negative (T+B-) FCXM, is the expected result in the presence of HLA class I antibodies. A T-cell-negative, B-cell-positive (T-B+) FCXM is the anticipated result in the presence of HLA class II antibodies only since HLA class II antigens are expressed on B cells but not on resting T cells.

Sample Requirement

T and B cell Crossmatch Sample Requirement:

· One tube of ACD blood from the donor shipped overnight at ambient temperature

· One tube of red top blood from the recipient shipped at ambient temperature

Crossmatch

HLA & Transplant

Contact Information

Laboratory Hours

Sample Collection

At-Home Tests

Sample Collection

Kashi Laboratories works directly with providers to make ordering tests as easy as possible.

Kashi Laboratories works directly with providers to make ordering tests as easy as possible.

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Kashi Laboratories works directly with providers to make ordering tests as easy as possible.

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