Cross-matches on donor cadaver retinal pigment epithelial cells in corneal risk patients.
BACKGROUND
Allografts can be rejected either through the antibody-mediated or cellular pathways. The objective of this study was to look at the extent of antibody formation in patients awaiting re-keratoplasty using cross-matches on cadaver retinal pigment epithelial (RPE) cells.


METHODS
Cadaver RPE cells were derived by trypsin digestion from donor eyes (n = 1200). After 3 days of cell cultivation, the cells were adherent and began to lose their pigment. By day 7 most cells were clear and grew as a polygonal monolayer. MHC class I expression by RPE cells was studied by the W6/32 (anti-HLA-A, B, C) monoclonal antibody (MoAb) and that of class II (HLA-DR) by the 136 MoAb. Normal RPE cells express few class I and no detectable class II antigens. For the induction of MHC expression, cells were subsequently stimulated with 250 U/ml of recombinant gamma-interferon for 5 days. Cells were used for tissue typing and also for cross-matches with recipient serum. Cross-matches were subsequently performed and measured by flow cytometry.


RESULTS
Both class I and class II antigens were strongly enhanced, as could be shown by immunohistochemical staining. Some 20% of those patients awaiting rekeratoplasty (n = 60) were positive for anti-HLA antibodies. In one case anti-DR3 antibodies were detected in a recipient who had had several rejection episodes after keratoplasty.


CONCLUSIONS
RPE cells are not only useful for cadaver post-mortem HLA typing but also for donor-specific cross-matches. The degree of antibody formation after keratoplasty in rejecting patients was, however, low. This may imply that anti-HLA antibodies are not the major cause of corneal graft loss after keratoplasty.
Zavazava
N
N
Institute of Immunology, University of Kiel, Germany.
Nölle
B
B
Duncker
G
G
Jenisch
S
S
Westphal
E
E
Eckstein
V
V
Müller-Ruchholtz
W
W
D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology; D002102:Cadaver; D002478:Cells, Cultured; D003315:Cornea / Q000276:immunology*; D005434:Flow Cytometry; D006084:Graft Rejection / Q000276:immunology*; D006085:Graft Survival / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000032:analysis* / Q000276:immunology; D006650:Histocompatibility Testing / Q000379:methods; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D015948:Keratoplasty, Penetrating / Q000276:immunology*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D011994:Recombinant Proteins; D012086:Reoperation; D012307:Risk Factors; D014019:Tissue Donors; D014184:Transplantation, Homologous
D000911:Antibodies, Monoclonal; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; D007371:Interferon-gamma