engleski

HLA typing of kidney allograft biopsy samples – importance for the donor–specific anti–hla antibody identification

INTRODUCTION: Detection of human leukocyte antigen (HLA) donor-specific antibodies (DSAs) is important for evaluating humoral immune status of patients pre- and post-transplantation. Both recipient and donor HLA allele typing data, ideally for all 11 immunogenic HLA loci (HLA-A, - B, -C, -DRB1, DRB3/4/5, -DQA1/DQB1 and - DPA1/DPB1), are the prerequisite for the accurate identification and detection of DSAs. In a majority of patients that have been transplanted long ago or transplanted outside our transplantation program the main obstacle for this analysis is the lack of stored donors’ blood or tissue samples. CASE REPORT: Here we report the methodology, which we used to overcome the situation of the missing donors’ blood samples by using the tissue undertaken from the kidney allograft biopsy. In three cases kidney transplantations (Ktx) were performed 19, 18 and 13 years ago and in one case Ktx was performed abroad. A tiny sample of kidney allograft tissue was used for DNA extraction and further HLA typing with polymerase chain reaction- specific sequence primers (PCR-SSP) and/or polymerase chain reaction-sequence-specific oligonucleotides (PCR-SSO) methods. In all four cases the obtained HLA typing result represented a “mixture” of both patient and donor HLA phenotypes, which allowed us to determine only the mismatched donor HLA antigens by deduction and comparison with the patients’ own HLA phenotype. In three cases, DSAs were positive: in case #1 for DRB4 and DQB1 alleles ; in case #3 for DPB1 and in case #4 for DQA1 alleles. In case #2, the locus specificity in obs. was DRB3 and the presence of DSAs was excluded. CONCLUSION: In summary, in all cases the kidney allograft biopsy sample was a useful source for DNA extraction and further HLA typing of the sample, which enabled us to identify possible donor immunogenes to which patient could form DSAs and to analyse the patients’ antibody profile for the presence or absence of DSAs.

HLA ; kidney transplantation ; biopsy samples

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