Human leukocyte antigen-G expression after heart transplantation is associated with a reduced incidence of rejection.
BACKGROUND
Human leukocyte antigen (HLA)-G, a nonclassic major histocompatibility complex class I molecule expressed in the extravillous cytotrophoblast at the feto-maternal interface, is known to protect the fetus from maternal cellular immunity. In a preliminary study, we showed that HLA-G is expressed in the hearts of some patients after heart transplantation.


RESULTS
In the present study, a larger number of patients was investigated to confirm this finding and to look for possible correlations between HLA-G expression and the number and types of rejection. Expression of HLA-G in endomyocardial biopsy specimens was investigated by immunohistochemical analysis, and detection of the soluble HLA-G in the serum was performed by immunoprecipitation followed by Western blot analysis. HLA-G was detected in the biopsy specimens and serum of 9 of 51 patients (18%). The number of episodes of acute rejection was significantly lower in HLA-G-positive patients (1.2+/-1.1) as compared with HLA-G-negative patients (4.5+/-2.8) (P<0.001). No chronic rejection was observed in HLA-G-positive patients, whereas 15 HLA-G-negative patients had chronic rejection (P<0.032). A longitudinal study of these patients reveals that the status of HLA-G expression was maintained after 6 months both in serum and in biopsy specimens. During this period, HLA-G-positive patients did not have chronic rejection.


CONCLUSIONS
There is a significant correlation between rejection and HLA-G expression in the heart after transplantation. HLA-G expression and its effect in reducing the incidence and severity of rejection seem to be stable throughout the evolution.
Lila
Nermine
N
Laboratory for the Study of Cardiac Grafts and Prostheses, University of Pierre et Marie Curie, Broussais Hospital, Paris, France. nerminelila@yahoo.fr
Amrein
Catherine
C
Guillemain
Romain
R
Chevalier
Patrick
P
Latremouille
Christian
C
Fabiani
Jean-Noël
JN
Dausset
Jean
J
Carosella
Edgardo D
ED
Carpentier
Alain
A
D000328:Adult; D000368:Aged; D004699:Endocardium / Q000378:metabolism; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism*; D006680:HLA Antigens / Q000378:metabolism*; D059951:HLA-G Antigens; D016027:Heart Transplantation; D006648:Histocompatibility; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I