[Show abstract][Hide abstract] ABSTRACT: Previous studies had shown that donor-specific anti-HLA antibodies may highly influence the survival rate of corneal allografts, although the anterior chamber generally represents an immune-privileged compartment of the eye. We postulated that the introduction of a novel crossmatch procedure for the detection of donor-specific anti-HLA antibodies in recipients awaiting a corneal graft would be adequate to investigate their influence on the outcome of the graft survival. The Antibody Monitoring System (AMS) HLA class I & II crossmatch ELISA was adapted for the use of material from the outer scleral rim instead of blood lymphocytes to isolate the donors' HLA molecules. In case of detectable donor-specific anti-HLA class I and/or class II antibodies (DSA) this result was confirmed using an identification ELISA to specify the detectable recipient's anti-HLA antibodies. PCR-based genetic tissue typing of the donors was performed also using their outer scleral rims. 45 recipients of corneal grafts were analyzed for DSA prior to or after grafting, respectively. 75% of the recipients with preformed DSA exhibited immunological complications up to the complete graft loss in four cases during the first two months. In contrast 77% of the recipients without DSA did not show any complications during the follow up period of averagely 18months. Only two cases of graft loss were observed in this group after 17 and 23months, respectively. The results demonstrate the impact of preventing donor-specific anti-HLA antibodies which are for the first time reliably detectable in any laboratory's daily work using the adapted AMS-ELISA.
[Show abstract][Hide abstract] ABSTRACT: Antibodies directed against HLA antigens of a given organ donor represent the dominating reason for hyper-acute or acute allograft
rejections. In order to select recipients without donor-specific antibodies, a standard crossmatch (CM) procedure, the complement-dependent
cytotoxicity assay (CDC), was developed. This functional assay strongly depends on the availability of isolated vital lymphocytes
of a given donor. However, the requirements of the donor’s material may often not be fulfilled, so that the detection of the
antibodies directed against HLA molecules is either impaired or becomes completely impossible. To circumvent the disadvantages
of the CDC procedure, enzyme-linked immunosorbent assay (ELISA)-based and other solid phase-based ELISA-related techniques
have been designed to reliably detect anti-HLA antibodies in recipients. Due to the obvious advantages of these novel technologies,
when compared with the classical CDC assay, there is an urgent need to implement them as complementary methods or even as
a substitution for the conventional CDC crossmatch that is currently being applied by all tissue typing laboratories.