Flow cytometric crossmatch for kidney transplantation

Area of Science:

• Immunology
• Transplantation Science
• Clinical Pathology

Background:

• Accurate crossmatching is crucial for successful kidney transplantation, minimizing antibody-mediated rejection.
• Traditional methods like National Institutes of Health (NIH) and antihuman globulin (AHG) microlymphocytotoxicity assays have limitations in sensitivity.
• Flow cytometry crossmatch (FCXM) offers a potentially more sensitive alternative for detecting clinically significant antibodies.

Purpose of the Study:

• To compare the sensitivity and clarity of flow cytometry crossmatch (FCXM) against standard NIH and AHG microlymphocytotoxicity methods.
• To evaluate the diagnostic performance of FCXM in patients with high panel reactive antibodies or related donor pairs.

Main Methods:

• Serum samples from 49 patients with panel reactive antibodies >15% and 17 related donor pairs were analyzed.
• Crossmatching was performed using three techniques: flow cytometry crossmatch (FCXM), NIH microlymphocytotoxicity, and AHG microlymphocytotoxicity.
• Statistical analysis was used to compare the results and determine significant differences.

Main Results:

• Flow cytometry crossmatch (FCXM) detected positive T- and B-cell crossmatches in 28.9% of cases where NIH and AHG methods were negative.
• When FCXM T-cell and B-cell crossmatches were negative, NIH and AHG methods also yielded negative results.
• Significant differences (p < 0.0001) were observed between FCXM and NIH, and between FCXM and AHG results.
• FCXM demonstrated 4-16 times higher sensitivity than AHG and 8-32 times higher sensitivity than NIH methods.

Conclusions:

• Flow cytometry crossmatch (FCXM) provides clear and highly sensitive results for antibody detection in kidney transplantation.
• FCXM is significantly more sensitive than both NIH and AHG microlymphocytotoxicity assays.
• Combining FCXM with NIH and AHG methods is recommended for comprehensive crossmatching in kidney transplantation.