A novel procedure of flow cytometry lymphocyte crossmatch test with high sensitivity using human lymphocytes in renal transplantation

Abstract

In renal transplantation, it is immunologically critical to detect donor-specific HLA antibodies (DSA) at a highly sensitive level before transplantation to avoid antibody-mediated acute rejection. We conducted basic research on refining the conventional flow cytometry lymphocyte crossmatch-IgG (FCXM-IgG) test to detect HLA antibodies at a highly sensitive level and on standardizing this novel procedure. We measured the levels of FCXM-IgG and LABScreen single-IgG using human donor lymphocytes in serum samples of 78 renal transplant recipients who visited the outpatient clinic of the Department of Surgery III at Tokyo Women’s Medical University. The correlation coefficients between FCXM-IgG MFI level and LABScreen single-IgG nMFI level were as good as about 0.8 for both B and T cells. These coefficients measured in linear values were almost equal to those measured in channel values. Even if we consider that the LABScreen single-IgG level could be affected by the coexistence of natural antibodies to some extent, we demonstrated in this study that the measured levels of FCXM-IgG and LABScreen single-IgG with fluorescence intensity correlated well with each other.