Allocation to highly sensitized patients based on acceptable mismatches results in low rejection rates comparable to nonsensitized patients.

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation.

Kidney allocation based on proven acceptable antigens results in superior graft survival in highly sensitized patients.

Highly sensitized renal transplant candidates accumulate on transplant waiting lists since they produce antibodies to many HLA antigens, which in this way become unacceptable. Organ allocation to these patients is usually based on avoiding transplantation of organs bearing these unacceptable antigens. In contrast, allocation through the Eurotransplant Acceptable Mismatch (AM) program is based on extension of the patient's own HLA type with so-called acceptable HLA antigens to which strictly no antibodies are formed, as shown by extensive laboratory testing.

The 25th anniversary of the Eurotransplant Acceptable Mismatch program for highly sensitized patients.

In 2014, the Eurotransplant Acceptable Mismatch (AM) program celebrated its 25th anniversary. The AM program was initiated to enhance transplantation of highly sensitized patients awaiting a renal transplant within the Eurotransplant region. Unlike the regular renal transplant allocation, in which the histocompatibility parameters consist of the degree of compatibility with the patient's human leucocyte antigen (HLA) type and the absence of unacceptable antigens, the AM program is based on compatibility of the possible donor with the combination of the patient's HLA type and the acceptable antigens.

The presence of HLA-antibodies in recurrent miscarriage patients is associated with a reduced chance of a live birth.

Anti-paternal HLA-antibodies are considered a harmless phenomenon during most pregnancies, whereas their role in recurrent miscarriage (RM) patients is disputed. In contrast to primary RM, patients with secondary RM have carried a fetus to term pregnancy prior to a series of miscarriages, which increases the chance that allogeneic fetal cells appear in the maternal circulation. This study investigates the frequency of HLA-antibodies in secondary RM, primary RM patients and parous controls and analyzes whether the presence of HLA-antibodies in early pregnancy is associated with pregnancy outcome.

The optimal chain length for kidney paired exchanges: an analysis of the Dutch program.

Living donor kidney exchange programs offer incompatible donor-recipient pairs the opportunity to be transplanted. To increase the number of these transplants, we examined in our actual donor-recipient couples how to reach the maximum number of matches by using different chain lengths. We performed 20 match procedures in which we constructed four different chain lengths: two, up to three, up to four and unlimited.

Hurdles, barriers, and successes of a national living donor kidney exchange program.

Background: Living donor kidney exchange is now performed in several countries. However, no information is available on the practical problems inherent to these programs. Here, we describe our experiences with 276 couples enrolled in the Dutch program.

A flexible national living donor kidney exchange program taking advantage of a central histocompatibility laboratory: the Dutch model.

The shortage of deceased donor kidneys for transplantation has resulted in the expansion of living donation programs. A number of possibilities have been explored, since it became clear that donors do not need to be genetically related to their recipients. Apart from classical direct donation, other options such as paired exchange, list exchange, altruistic donation and domino paired exchange programs have been implemented.

A highly efficient living donor kidney exchange program for both blood type and crossmatch incompatible donor-recipient combinations.

Background: Lack of deceased donors for kidney transplant patients in the Netherlands encouraged alternative options to expand the living donor pool for recipients who have a willing donor but cannot donate directly because of a positive crossmatch or ABO blood type incompatibility. A national donor kidney exchange was considered as a possible solution.

Methods: From January 2004 until June 2006, 146 couples from seven kidney transplantation centers were enrolled and participated in 10 match procedures.

Single-antigen-expressing cell lines are excellent tools for detecting human leukocyte antigen-C-reactive antibodies in kidney transplant recipients.

Background: Human leukocyte antigen (HLA)-C is expressed on nucleated cells and platelets in lower levels than HLA-A,B, and its antigens are in linkage disequilibrium with HLA-B antigens. Therefore, HLA-C antibody detection is difficult. The authors questioned whether HLA-C could serve as a target in clinical kidney transplantation using a newly developed assay.

The acceptable mismatch program as a fast tool for highly sensitized patients awaiting a cadaveric kidney transplantation: short waiting time and excellent graft outcome.

There are many highly sensitized patients on the kidney waiting lists of organ exchange organizations because it is difficult to find a crossmatch negative cadaver kidney for these patients. Recently, several protocols have been developed to remove the donor-specific human leukocyte antigen (HLA) antibodies from the serum of these patients before transplantation. These approaches, including the use of intravenous immunoglobulins, plasmapheresis and immunoglobulins (plasmapheresis-cytomegalovirus-immunoglobulin), and immunoabsorption, seem to lead to a certain success rate, although the additional immunosuppression necessary to remove and control the production of donor-specific alloantibodies may have its impact on the short-term (infections) and long-term (incidence of cancer) immune surveillance.

The number of amino acid triplet differences between patient and donor is predictive for the antibody reactivity against mismatched human leukocyte antigens.

Background: The correlation between antibody production against mismatched donor human leukocyte antigens (HLA) and the number of amino acid sequence mismatches was analyzed in patients who rejected a kidney transplant (n=146).

Methods: A similar analysis was performed for the antibody production of women against the paternal HLA antigens of their child (n=1,397). The amino acid sequence (triplet) differences were analyzed using the HLAMatchmaker algorithm.

Formation of donor-specific human leukocyte antigen antibodies after kidney transplantation: correlation with acute rejection and tapering of immunosuppression.

Background: Before kidney transplantation, a serological crossmatch is routinely performed between donor and recipient to prevent hyperacute rejection by donor-specific anti-human leukocyte antigen (HLA) antibodies. After transplantation, the presence of these antibodies is not routinely monitored. We wanted to know whether donor-specific anti-HLA antibodies are detectable during acute rejection (AR), before or after reduction of immunosuppression in kidney transplant recipients who were converted from cyclosporine A (CsA) to the less nephrotoxic azathioprine (AZA) or mycophenolate mofetil (MMF) at 1 year after transplantation.

A broad and strong humoral immune response to donor HLA after implantation of cryopreserved human heart valve allografts.

Cryopreserved human heart valves are used for valve replacement in patients with congenital or acquired heart disease. Although no blood group or human leukocyte antigens (HLA) matching is performed and no immunosuppression is administered, the clinical results are relatively good. After valve replacement, the majority of the patients develop HLA antibodies, whereas a smaller group of patients shows valve-related events at the long term after right ventricular outflow tract reconstruction.