Rejection of a kidney transplant does not always lead to priming of cytotoxic T cells against mismatched donor HLA class I antigens.
BACKGROUND
Previous studies showed that graft rejection is often associated with the presence of primed cytotoxic T cells (CTLs) with a high avidity for donor cells. Similar high avidity CTLs have been found in individuals who have formed IgG anti-HLA antibodies. The presence of such CTLs to a specific HLA mismatch is therefore considered to be a reflection of an activated immune system, and a contraindication for retransplantation with a donor sharing this particular HLA class I mismatch.


METHODS
In our study we investigated whether patients have always primed CTLs against all individual HLA class I mismatches present on a rejected graft. Therefore, 14 patients who had undergone transplantectomy after irreversible kidney graft rejection were analyzed with respect to donor-specific CTLp frequencies and the presence or absence of high avidity CTLs directed against HLA class I mismatches present on the rejected graft.


RESULTS
Patients, who have not formed anti-HLA antibodies against the donor have mainly naive CTLs. Most of the patients, that have developed IgG anti-HLA antibodies against a donor mismatch, have primed CTLs directed against that particular mismatch. However, patients with IgM anti-HLA antibodies only, and patients with IgG anti-HLA antibodies in historical sera but no IgG anti-HLA antibodies in current sera, have mainly naive CTLs against the donor HLA mismatch.


CONCLUSIONS
Our results suggest that it is not always necessary to exclude repeated HLA class I mismatches for a subsequent transplantation. In addition to good anti-HLA antibody screening, the CTLp-assay may be a useful tool for donor-selection in retransplant candidates.
van Kampen
C A
CA
Department of Immunohematology & Blood Transfusion, Leiden University Medical Center, The Netherlands.
Versteeg-van der Voort Maarschalk
M F
MF
Roelen
D L
DL
ten Berge
I J
IJ
Claas
F H
FH
D000906:Antibodies / Q000032:analysis; D006084:Graft Rejection / Q000276:immunology*; D006648:Histocompatibility / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D016030:Kidney Transplantation / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014019:Tissue Donors
D000906:Antibodies; D015395:Histocompatibility Antigens Class I; D007074:Immunoglobulin G; D007075:Immunoglobulin M