ABSTRACT
The novel HLA-DPB1*14:01:15 allele differs from DPB1*14:01:01:01 by change of C > T in exon 3.
Subject(s)
Alleles , Base Sequence , Exons , HLA-DP beta-Chains , Histocompatibility Testing , Tissue Donors , Humans , HLA-DP beta-Chains/genetics , Brazil , Sequence Analysis, DNA/methods , Bone Marrow , Sequence Alignment , Codon , Bone Marrow TransplantationABSTRACT
The study aimed to investigate the impact of HLA-DPB1 allelic and molecular mismatches on the occurrence of acute rejection (AR) and low 5-year graft function (5Y-GF) in first kidney transplant (KT) recipients. This is a single center retrospective study of 130 deceased donor KT recipients transplanted between 2014 and 2016. HLA-DPB1 allelic MM and the following molecular MM (mMM) were analyzed: expression MM with the high expression G allele in the donor; T cell epitope MM (TCE MM); epitope MM (EMM), considering all six hypervariable regions (EMM-ABCDEF HVR), or only ABEF regions (EMM-ABEF HVR); eplet MM (EpMM); antibody-verified eplet MM (AbVer EpMM); and solvent accessible amino acid MM (SAMM). There was no association of allelic MM with AR or 5Y-GF. The variables independently associated (Cox regression analyses) with AR were high donor final creatinine, nonpermissive TCE MM, ABCDEF EMM load ≥6, EpMM load ≥6; SAMM load ≥5, and AbVer EpMM load ≥3. No association between any HLA-DPB1 mMM and 5Y-GF was observed when all 130 transplant recipients were considered. However, when transplants from expanded criteria donors were excluded, independent associations were detected (logistic regression analyses) with AbVerEpMM load ≥2, SAMM load ≥7, cerebro-vascular death, donor age, and AR. To our knowledge, this is the first study that shows that some HLA-DPB1 mMM are associated with AR and low 5Y-GF in a population of exclusively first kidney transplant recipients.
Subject(s)
Kidney Transplantation , Humans , Retrospective Studies , Histocompatibility Testing , Alleles , Risk Factors , Epitopes, T-Lymphocyte , Graft Rejection/geneticsABSTRACT
The novel HLA-DPB1*04:01:51 allele first described in a potential bone marrow donor from Brazil.
Subject(s)
Bone Marrow Transplantation , Bone Marrow , Alleles , Brazil , HLA-DP beta-Chains , High-Throughput Nucleotide Sequencing , Humans , Polymorphism, Single NucleotideABSTRACT
BACKGROUND: The impact of HLA-DPB1 compatibility and its role as a transplantation antigen in haploidentical-related hematopoietic stem cell transplant (haplo-R-HSCT) have not been established, and a negative effect on survival has been suggested. OBJECTIVE: The objective of the determine was to study the frequency and clinical effects of incompatibility at the HLA-DPB1 locus in the haplo-R-HSCT setting. METHODS: Clinical records and electronic files of 91 patients with a hematological disease who underwent haplo-HSCT from January 2009 to October 2017 in a university medical center were scrutinized. Overall survival (OS) was estimated by the Kaplan-Meier method; the cumulative incidence of transplant-related mortality (TRM) and relapse rates was determined. Acute graft-versus-host disease was assessed by binary logistic regression. Cox regression model with a 95% confidence interval was used to examine the association between the different variables and their effect on OS. RESULTS: Of the 91 donor-recipient pairs, 24 (26.37%) shared complete DPB1 identity, 60 (65.93%) had a mismatch at one allele, and 7 (7.70%) were mismatched at two alleles. Twenty-four different HLA-DPB1 alleles were found; the most frequent were DPB1*04:01 (34.1%) and DPB1*04:02 (27.5%). Two-year OS, the cumulative incidence of TRM and relapse was 51.3 ± 6.8%, 28 ± 6% and 60 ± 7.8% for all haplo-related transplants, respectively, with no statistical difference between HLA-DPB1 matched and partially matched patients. In Cox regression analysis, no risk factors associated with OS, TRM, or relapses were identified. CONCLUSION: HLA-DPB1 mismatching in the haplo-R-HSCT setting did not influence transplant outcomes and was clinically tolerable. A high degree of homozygosity was found.
Subject(s)
HLA-DP beta-Chains , Hematologic Diseases/surgery , Hematopoietic Stem Cell Transplantation/methods , Transplantation, Haploidentical , Adolescent , Adult , Child , Child, Preschool , Donor Selection , Female , Hematologic Diseases/mortality , Humans , Infant , Male , Middle Aged , Patient Selection , Retrospective Studies , Survival Rate , Treatment Outcome , Young AdultABSTRACT
ABSTRACT Background: The impact of HLA-DPB1 compatibility and its role as a transplantation antigen in haploidentical-related hematopoietic stem cell transplant (haplo-R-HSCT) have not been established, and a negative effect on survival has been suggested. Objective: The objective of the determine was to study the frequency and clinical effects of incompatibility at the HLA-DPB1 locus in the haplo-R-HSCT setting. Methods: Clinical records and electronic files of 91 patients with a hematological disease who underwent haplo-HSCT from January 2009 to October 2017 in a university medical center were scrutinized. Overall survival (OS) was estimated by the Kaplan-Meier method; the cumulative incidence of transplant-related mortality (TRM) and relapse rates was determined. Acute graft-versus-host disease was assessed by binary logistic regression. Cox regression model with a 95% confidence interval was used to examine the association between the different variables and their effect on OS. Results: Of the 91 donor-recipient pairs, 24 (26.37%) shared complete DPB1 identity, 60 (65.93%) had a mismatch at one allele, and 7 (7.70%) were mismatched at two alleles. Twenty-four different HLA-DPB1 alleles were found; the most frequent were DPB1*04:01 (34.1%) and DPB1*04:02 (27.5%). Two-year OS, the cumulative incidence of TRM and relapse was 51.3 ± 6.8%, 28 ± 6% and 60 ± 7.8% for all haplo-related transplants, respectively, with no statistical difference between HLA-DPB1 matched and partially matched patients. In Cox regression analysis, no risk factors associated with OS, TRM, or relapses were identified. Conclusion: HLA-DPB1 mismatching in the haplo-R-HSCT setting did not influence transplant outcomes and was clinically tolerable. A high degree of homozygosity was found.
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Young Adult , Hematopoietic Stem Cell Transplantation/methods , HLA-DP beta-Chains , Transplantation, Haploidentical , Hematologic Diseases/surgery , Survival Rate , Retrospective Studies , Treatment Outcome , Patient Selection , Donor Selection , Hematologic Diseases/mortalityABSTRACT
Genetic polymorphism of human leukocyte antigen (HLA)-DPA1 and -DPB1 loci was studied in 154 unrelated individuals from Guadeloupe, an archipelago of five islands located in the Carribean Sea. Thirty different DPB1 and eight different DPA1 alleles were observed with a heterozygosity index of 0.87 and 0.78, respectively. This high degree of heterozygosity corresponds with those found in African populations. The DPB1* 01:01:01 allele was most frequent (0.260), followed by 02:01:02 (0.143) and 04:01:01 (0.127). The DPA1 alleles 01:03 (0.380), 02:01 (0.302), 02:02 (0.175) and 03:01 (0.123) were identified in >35 individuals each, whereas 01:04, 01:05 and 04:01 were present only once. Haplotype estimations revealed the presence of 39 different haplotypes, with DPB1*01:01:01-DPA1*02:02 and DPB1*02:01:02-DPA1*01:03 as the most frequent (0.143 and 0.140, respectively). A striking difference was observed in DPB1/DPA1 associations between DPB1*04:02 and *105:01, that have identical exon 2 sequences. DPB1*04:02 was exclusively associated with DPA1*01:03, whereas DPB1*105:01 was present with DPA1*03:01, *03:02 or *04:01. This implies that the DP molecules are actually different, and this difference is relevant to consider in studies on the function of HLA-DP molecules in transplantation. Overall, HLA-DPA1 and DPB1 allele frequencies and haplotypes of the population of Guadeloupe were most similar to African populations, with characteristic alleles and haplotypes that bespeaks the admixture with other ethnicities.
Subject(s)
Alleles , Gene Frequency/genetics , Genetics, Population , HLA-DP alpha-Chains/genetics , HLA-DP beta-Chains/genetics , Haplotypes/genetics , Adult , Amino Acid Motifs , Child, Preschool , Epitopes/chemistry , Epitopes/immunology , Female , Guadeloupe , Humans , MaleABSTRACT
The new HLA-DPB1*142:01 allele differs from DPB1*26:01:02 and DPB1*56:01 at codons 65 (I65>L65) and 35 (F35>Y35), respectively.