- Transfusion & Apheresis Science. 2002 June,; 26(3):197-204.
Photopheresis (ECP) is a new immunomodulatory therapy in which recipient lymphocytes are treated extracorporeally with 8-methoxypsoralen (8-MOP) and ultraviolet light. The treatment seems to induce an inhibition of both umoral and cellular rejections after transplantation. More than 160 transplanted patients have been treated with ECP (107 heart, 30 kidney, 24 lung and 1 liver) in different studies. Indication for ECP included acute rejection, recurrent/refractory rejection, prophilaxis of rejection, need of reducing standard immunosuppression. Patient survival is satisfactory. Only one study where ECP was used as the last therapeutic resource in very compromised patients shows a high rate of mortality. On the contrary, when ECP was used earlier after the failure of a first immunosuppressive line the outcome was better with a very low mortality. An hystological resolution of acute rejection is reported in 89% of cardiac transplant patients. The rate of response is similar even in the other transplanted patients treated with ECP. A better control of alloreactivity has been also reported in both cardiac and renal transplant patients with recurrent rejection. In renal allograft the treatment induces a reduction of both lymphocytes and monocytes infiltrate and downregulates the expression of HLA-DR and integrins ICAM-1 and VCAM-1 on tubular cells. Markers of fibrogenesis such as TGFbeta1 and ASMA are only moderately reduced with a more focal pattern of distribution in the post-ECP specimens. The optimal schedule and the length of treatment are still unclear and probably a patient-tailored treatment is needed at least in responder patients. ECP is effective for patients resistant to conventional treatments, particularly when it is started early. This beneficial effect is obtained without the complications typically encountered with immunosuppressive regimens used to control rejection.
https://pubmed.ncbi.nlm.nih.gov/12126206/
BACKGROUND:
There is no standard definition for “HLA incompatible” transplants. For the first time, we systematically assessed how HLA incompatibility was defined in contemporary peer-reviewed publications and its prognostic implication to transplant outcomes.
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METHODS:
We combined 2 independent searches of MEDLINE, EMBASE, and the Cochrane Library from 2015 to 2019. Content-expert reviewers screened for original research on outcomes of HLA-incompatible transplants (defined as allele or molecular mismatch and solid-phase or cell-based assays). We ascertained the completeness of reporting on a predefined set of variables assessing HLA incompatibility, therapies, and outcomes. Given significant heterogeneity, we conducted narrative synthesis and assessed risk of bias in studies examining the association between death-censored graft failure and HLA incompatibility.
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RESULTS:
Of 6656 screened articles, 163 evaluated transplant outcomes by HLA incompatibility. Most articles reported on cytotoxic/flow T-cell crossmatches (n = 98). Molecular genotypes were reported for selected loci at the allele-group level. Sixteen articles reported on epitope compatibility. Pretransplant donor-specific HLA antibodies were often considered (n = 143); yet there was heterogeneity in sample handling, assay procedure, and incomplete reporting on donor-specific HLA antibodies assignment. Induction (n = 129) and maintenance immunosuppression (n = 140) were frequently mentioned but less so rejection treatment (n = 72) and desensitization (n = 70). Studies assessing death-censored graft failure risk by HLA incompatibility were vulnerable to bias in the participant, predictor, and analysis domains.
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CONCLUSIONS:
Optimization of transplant outcomes and personalized care depends on accurate HLA compatibility assessment. Reporting on a standard set of variables will help assess generalizability of research, allow knowledge synthesis, and facilitate international collaboration in clinical trials.
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