Identification of four novel HLA alleles: HLA-B*27:265, -B*35:569, -DRB1*08:117 and -DPB1*1435:01.

Identification of four new HLA alleles (B*27:265, B*35:569, DRB1*08:117, and DPB1*1435:01) in Brazilian bone marrow donors.

Interlocus gene conversion: Identification of HLA-A*23:128 in a Brazilian bone marrow donor.

Identification of novel HLA-A*23:128 allele generated by interlocus gene conversion in Brazilian bone marrow donor.

Impact of COVID-19 pandemic on cord blood banking and transplantation.

Umbilical cord blood is a rich source of hematopoietic stem cells that has been used for transplantation for over 30 years, especially when there is no compatible hematopoietic stem cell donor available. Its use has decreased more recently, since the development of methods to improve haploidentical transplants has allowed the use of mobilized peripheral blood as a source of hematopoietic stem cells. Public cord blood banks collect, process and store cord blood samples from voluntary donations. In addition, many public banks are involved in research to enhance hematopoietic stem cell therapies and develop new treatments for haematological and genetic diseases. The COVID-19 pandemic, which emerged in 2019, has had a profound and wide-ranging impact on human health and treatment. The area of hematopoietic stem cell transplantation was deeply affected by reductions in bone marrow, peripheral blood and cord blood donations; logistical challenges; exposure of healthcare workers and other challenges. The present study reviews the impact of the COVID-19 pandemic on cord blood banking and transportation around the world with a special focus on Brazil.

Creating an HLA-homozygous iPS cell bank for the Brazilian population: Challenges and opportunities.

Identifying human leukocyte antigen (HLA) haplotype-homozygous donors for the generation of induced pluripotent stem (iPS) cell lines permits the construction of biobanks immunologically compatible with significant numbers of individuals for use in therapy. However, two questions must be addressed to create such a bank: how many cell lines are necessary to match most of the recipient population and how many people should be tested to find these donors? In Japan and the UK, 50 and 100 distinct HLA-A, -B, and -DRB1 triple-homozygous haplotypes would cover 90% of those populations, respectively. Using data from the Brazilian National Registry of Bone Marrow Donors (REDOME), encompassing 4,017,239 individuals, we identified 1,906 distinct triple-homozygous HLA haplotypes. In Brazil, 559 triple-homozygous cell lines cover 95% of the population, and 3.8 million people would have to be screened. Finally, we show the contribution of the 30 most frequent triple-homozygous HLA haplotypes in Brazil to populations of different countries.

HLA-A, HLA-B and HLA-DRB1 haplotype frequencies in Piauí's volunteer bone marrow donors enrolled at the Brazilian registry.

This study aimed to report the antigen and haplotype frequencies (HFs) of volunteer bone marrow donors (VBMDs) from the state of Piauí who were enrolled in the National Volunteer Bone Marrow Donor Registry (REDOME). The research subjects were 21,943 volunteer bone marrow donors, predominantly young adult women (53.3%). The most frequent allelic group was HLA-A2, followed by -DRB1*13, -DRB1*04, -DRB1*07, -B*15, -B∗35, -B*44, -A*24 and -A*03. Of the 2,704 haplotypes observed, the three most frequent haplotypes were A*29 B*44 DRB1*07 (1.45%), A*01 B*08 DRB1*03 (1.4%) and A*03 B*07 DRB1*15 (0.92%). These three haplotypes were in linkage disequilibrium. PCA showed that 98% of the VBMDs have HLA allele frequencies that are very similar to those from Teresina, the capital city of Piauí. According to the PCA results, these municipalities are distributed with a close proximity to Teresina, which in turn has a close genetic proximity to the Hispanic ethnicity, intermediate proximity to Caucasians and Africans and a distant kinship to Amerindians. The hierarchical proximity of the population of Piauí to the Portuguese and Hispanic populations to shows the strong influence of the latter on the former.

Análise da Capacidade do REDOME/RENACORD em suprir as necessidades dos pacientes registrados no REREME

Classical Hodgkin lymphoma (cHL) is characterized by a small number of neoplastic, Hodgkin and Reed-Sternberg (H-RS) cells in a background of non-neoplastic, mainly B and T cells. This tumor microenvironment has been considered to be a manifestation of host immune reactions to malignant cells. Since children and adults have difference in the constitution and functionality of the immune system, and pathogenic events differ in pediatric and adult cHL, it is likely that the tumor microenvironment in cHL may be distinct in the pediatric setting. In this study, we analyzed a series of pediatric cHL (100 cases) regarding the clinical and histological characteristics, as well as composition of the tumor microenvironment by CD3, CD4, C-maf, T-bet, FoxP3, CD8, Tia-1, Granzyme B (GrB) and CD20 immunostain and its prognostic impact. Proliferation index of neoplastic and benign infiltrating cells was determined by Ki67 immunostain. We determined also the IL10 -1082A/G, -819C/T and -592C/A genotype of single nucleotide polymorphisms (SNPs) and haplotypes by Allele-specific (AS) PCR and CTLA4 -1722 A/G, +49 A/G and CT60 A/G SNPs by allele discrimination with fluorogenic hydrolysis probes (Taqman® Applied Biosystems). Epstein-Barr virus (EBV) was determined by in situ hybridization (EBERs-ISH) and LMP1 immunostain. Age at diagnosis ranged from 3 to 18 years (median 14) with 27% of cases <10 years. Age and histologic subtype did not A prática clínica do transplante de células tronco hematopoéticas (TCTH) somente foi possível com a melhoria dos conhecimentos na área de imunologia e histocompatibilidade (HLA). Entre os fatores facilitadores está a obtenção de um doador HLA compatível que idealmente é um irmão, mas na maioria das vezes (70%) é um doador não aparentado. As alternativas viáveis para populações como a brasileira, com grande miscigenação, foram a expansão do Registro Brasileiro de Doadores de Medula Óssea – REDOME e da Rede de Bancos de Sangue de Cordão Umbilical e Placentário (SCUP) - BRASILCORD. O presente estudo teve por objetivo avaliar as frequências dos alelos e haplótipos de HLA identificados no REDOME, no Registro de Receptores – REREME e nas unidades de SCUP armazenadas no BRASILCORD e registradas no Registro Nacional de Sangue de Cordão - RENACORD. Trata-se de uma amostragem significativa da população brasileira, com cadastros oriundos de todas as regiões do país. As frequências de grupos alélicos HLA foram obtidas dos três bancos de dados e através do teste estatístico do qui-quadrado foram realizadas comparações das freqüências observadas entre os registros. Para determinação das frequências dos haplótipos utilizou-se o programa Arlequim 3.01. A constituição genética da população brasileira de doadores de medula óssea, calculada em janeiro de 2009 (887.616 doadores) foi composta de 21 grupos alélicos HLA-A*, 36 grupos alélicos HLA-B* e 13 grupos alélicos HLA-DRB1*. Esta constituição foi a mesma encontrada nos registros do REREME e RENACORD. A identificação de haplótipos presentes no cadastro do REREME e ausentes ou pouco frequentes no REDOME e no RENACORD assim como a análise da origem destes haplótipos mostrou a presença de haplótipos nunca descritos em outras populações. A análise dos alelos que compõem estes haplótipos mostra uma miscigenação entre grupos antropológicos distintos como asiáticos, negróides, indígenas e caucasianos. Os dados obtidos neste estudo contribuem para o estabelecimento dos critérios necessários para o planejamento estratégico de expansão do BRASILCORD e do próprio REDOME. Além desta contribuição, em função do número de indivíduos incluídos nos cadastros dos registros, trata-se da maior e mais diversificada fonte de informação sobre a constituição genética da população brasileira

Stem cell transplantation clinical practice was only possible with knowledge improvement in Immunology and Histocompatibility (HLA). Whereas transplants between HLA identical siblings ideally produce the best outcomes, the majority (70%) does not have one family donor and will depend on an unrelated donor. Possible alternatives for mixed populations as the Brazilian, include the expansion of the Volunteer Marrow Donor Brazilian Registry - REDOME and the Cord Blood Bank Network – BRASILCORD. The aim of the present study was to evaluate the HLA alleles and haplotypes frequencies in REDOME, REREME – Brazilian Receptor Registry and Brazilian Cord Blood Registry - RENACORD. This database can be considered a representative sample of the Brazilian population originated from all regions of the country. HLA alleles groups frequencies were obtained from the three Registries and were compared using qui square test. To determine haplotype frequencies, Arlequim 3,01 software was used. In this study we included, from 2004 till January 2009, 887616 donors and 21 HLA-A*, 36 HLA-B* and 13 HLA-DRB1* alleles groups were identified. Haplotypes existing in REREME database but absent or less frequent in REDOME and in RENACORD, as well as the analysis of haplotypes origins, revealed haplotypes identification never described before in other populations. The allele analysis of the haplotypes showed miscegenation among different anthropological groups such as Asians, Blacks, Indians and Caucasians. Data obtained in this study contributed to establish the necessary criteria for a strategic plan to expand BRASILCORD and REDOME as well. Moreover, considering the huge number of individuals evaluated, this study is one of the biggest and the most diverse source of information about the genetic profile of the Brazilian population.