This review highlights literature pertinent to chimerism analysis in the context of hematopoietic cell transplantation (HCT). We also conducted a survey of testing practices of program members of ...CIBMTR worldwide. Questions included testing methods, time points, specimen type, cell lineage tested and testing indications. Recent literature suggests that detection of low level mixed chimerism has a clinical utility in predicting relapse. There is also increasing recognition of HLA loss relapse to potentially guide rescue decisions in cases of relapse. These developments coincide with wider access to high sensitivity next generation sequencing (NGS) in clinical laboratories. Our survey revealed a heterogeneity in practices as well as in findings and conclusions of published studies. Although the most commonly used method is STR, studies support more sensitive methods such as NGS, especially for predicting relapse. There is no conclusive evidence to support testing chimerism in BM over PB, particularly when using a high sensitivity testing method. Periodic monitoring of chimerism especially in diagnoses with a high risk of relapse is advantageous. Lineage specific chimerism is more sensitive than whole blood in predicting impending relapse. Further studies that critically assess how to utilize chimerism testing results will inform evidence based clinical management decisions.
We examined current outcomes of unrelated donor allogeneic hematopoietic cell transplantation (HCT) to determine the clinical implications of donor-recipient HLA matching. Adult and pediatric ...patients who had first undergone myeloablative-unrelated bone marrow or peripheral blood HCT for acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, and myelodysplastic syndrome between 1999 and 2011 were included. All had high-resolution typing for HLA-A, -B, -C, and -DRB1. Of the total (n = 8003), cases were 8/8 (n = 5449), 7/8 (n = 2071), or 6/8 (n = 483) matched. HLA mismatch (6-7/8) conferred significantly increased risk for grades II to IV and III to IV acute graft vs host disease (GVHD), chronic GVHD, transplant-related mortality (TRM), and overall mortality compared with HLA-matched cases (8/8). Type (allele/antigen) and locus (HLA-A, -B, -C, and -DRB1) of mismatch were not associated with overall mortality. Among 8/8 matched cases, HLA-DPB1 and -DQB1 mismatch resulted in increased acute GVHD, and HLA-DPB1 mismatch had decreased relapse. Nonpermissive HLA-DPB1 allele mismatch was associated with higher TRM compared with permissive HLA-DPB1 mismatch or HLA-DPB1 match and increased overall mortality compared with permissive HLA-DPB1 mismatch in 8/8 (and 10/10) matched cases. Full matching at HLA-A, -B, -C, and -DRB1 is required for optimal unrelated donor HCT survival, and avoidance of nonpermissive HLA-DPB1 mismatches in otherwise HLA-matched pairs is indicated.
•High-resolution matching for HLA-A, -B, -C, and -DRB1 is required for optimal survival in myeloablative-unrelated donor transplantation.•HLA-DPB1 nonpermissive mismatches should be avoided in otherwise matched transplants to minimize overall mortality.
•Convalescent plasma as an adjunct treatment in moderate and severe COVID-19 disease.•Clinical improvement in COVID-19 disease following convalescent plasma treatment.•Mortality is significantly ...reduced in COVID-19 cases after convalescent plasma treatment.
To study the effectiveness of COVID-19 convalescent plasma (CCP) therapy for patients with moderate and severe COVID-19 disease.
This non-randomized prospective cohort study was conducted from May 21 to June 30, 2020, at four major tertiary hospitals in Kuwait. CCP was administered to 135 patients. The control group comprised 233 patients who received standard treatment. All patients (N = 368, median age 54 range 15–82) had laboratory-confirmed SARS-CoV-2 infection and either moderate or severe COVID-19 disease.
CCP treatment was associated with a higher rate of clinical improvement in patients with moderate or severe disease. Among those with moderate COVID-19 disease, time to clinical improvement was 7 days in the CCP group, versus 8 days in the control group (p = 0·006). For severe COVID-19 disease, time to clinical improvement was 7 days in the CCP group, versus 15.5 days in the control group (p = 0·003). In the adjusted analysis, patients with moderate disease treated with CCP had a significantly lower 30-day mortality rate. Compared to the control group, oxygen saturation improved within 3 days of CCP transfusion, and lymphocyte counts improved from day 7 in patients with moderate COVID-19 disease and day 11 in patients with severe disease. C-reactive protein levels declined throughout the first 14 days after CCP transfusion. None of the CCP patients developed a serious transfusion reaction.
The data show that administration of CCP is a safe treatment option for patients with COVID-19 disease with a favorable outcome in the rate of, and time to, clinical improvement.
Abstract This report describes the design of the eplet version of HLAMatchmaker to determine class II compatibility at the structural level. This matching algorithm is based on the hypothesis, ...developed from molecular modeling of crystallized antigen-antibody complexes, that functional epitopes are represented by patches of surface-exposed nonself-amino acid residues surrounded by residues within a 3-Å radius. Patch determinations with a molecular viewer of crystalline structural models downloaded from the Entrez Molecular Modeling Database Web site led to the identification of 44 DRB, 33DQB, 29 DQA, 20 DPB, and 9 DPA unique combinations of polymorphic positions. The residue compositions of these patches were then determined from amino acid sequences. This analysis resulted in a repertoire of 146 DRB, 74 DQB, 58 DQA, 45 DPB, and 19 DPA eplets. In many eplets, the residues are in short linear sequences, but many other eplets have discontinuous sequences of residues that cluster on or near the molecular surface. This analysis has also shown that all serologically defined DR and DQ antigens detectable by monospecific antibodies have unique eplets. Other eplets are present in groups of class II antigens, many of which appear as cross-reacting. The eplet version of HLAMatchmaker should be considered as a hypothetical model for the structural assessment of donor-recipient compatibility and the determination of mismatch acceptability for sensitized patients. This computer algorith can be downloaded from the HLA Matchmaker Webside at http://tpis.upmc.edu.
In subjects mismatched in the HLA alleles C*03:03/C*03:04 no allogeneic cytotoxic T-lymphocyte responses are detected in vitro. Hematopoietic stem cell transplantation (HSCT) with unrelated donors ...(UDs) showed no association between the HLA-C allele mismatches (CAMMs) and adverse outcomes; antigen mismatches at this and mismatches other HLA loci are deleterious. The absence of effect of the CAMM may have resulted from the predominance of the mismatch C*03:03/C*03:04. Patients with hematologic malignancies receiving UD HSCT matched in 8/8 and 7/8 HLA alleles were examined. Transplants mismatched in HLA-C antigens or mismatched in HLA-A, -B, or -DRB1 presented significant differences (P < .0001) in mortality (hazard ratio HR = 1.37, 1.30), disease-free survival (HR = 1.33, 1.27), treatment-related mortality (HR = 1.54, 1.54), and grade 3-4 acute graft-versus-host disease (HR = 1.49, 1.77) compared with the 8/8 group; transplants mismatched in other CAMMs had similar outcomes with HR ranging from 1.34 to 172 for these endpoints. The C*03:03/C*03:04 mismatched and the 8/8 matched groups had identical outcomes (HR ranging from 0.96-1.05). The previous finding that CAMMs do not associate with adverse outcomes is explained by the predominance (69%) of the mismatch C*03:03/03:04 in this group that is better tolerated than other HLA mismatches.
•Mismatches in alleles C*03:03/C*03:04 were most frequent (68.7%) among the transplants with a single allele level mismatch in HLA-C.•The 7/8 C*03:03/C*03:04 mismatch group was not significantly different from the 8/8 HLA matched transplants in any transplant outcome.
The annual meeting of the Association of Medical Laboratory Immunologists (AMLI) was convened virtually over the month of August. Prior to the emergence of the COVID-19 pandemic, AMLI's scientific ...committee had chosen the following topics as the focus of its 2020 meeting: Histocompatibility Testing and Transplant Immunology; Secondary Immunodeficiency and Immunotherapy Monitoring; ANA Update; and Emerging Infectious Diseases and New Algorithms for Testing. Given the central role of the discipline in the evaluation of the host response to infection, it was apt to add a separate session on antibody testing for SARS-CoV-2 infections to the original program. The current report provides an overview of the subjects discussed in the course of this meeting.
The objective of the present report was to analyze the opinions, attitudes, and practices of Baskent University students with regard to the impact of religion on organ donation and transplantation.
...We sent a web-based, 5-point Likert scale questionnaire (1: strongly disagree; 5: strongly agree) to capture the opinions and attitudes toward organ donation and transplantation after participants attended or did not a panel discussion on these topics.
We sent 361 E-mails and received 69 responses, of which 46 students attended the panel discussion. Most of the participants who attended were part of the faculty of medicine. Participants who did not attend were composed of students from other faculties at Baskent University. Religion played less of a role with regard to opinions on organ donation in those who did not attend. Of the attendees, 54.3% strongly agreed to become organ donors, 50% believed in the important role of religion in organ donation, and 54.3% believed that media sources play important roles in shaping public opinion on organ donation. The majority felt comfortable discussing organ donation with family and friends.
Although religion has an undeniable effect on the decision-making process, our survey showed that more than half of the participants were willing to become organ donors. Education, through the joint efforts of medical and religious scholars, as well as the media, should contribute to raising awareness on organ donation, thus contributing to increased access to transplantation worldwide.
Immune responses to lung-associated self-antigens (SAgs) have been implicated in chronic lung allograft rejection. The goals of this study were to determine the prevalence of pre-existing antibodies ...(Abs) to the SAgs in pulmonary diseases and the association between pre-existing Abs to SAgs and the development of primary graft dysfunction (PGD), donor-specific antibodies (DSA), and chronic rejection.
Pre- and post-transplant sera were analyzed from 317 lung transplant (LTx) recipients between 2000 and 2011 with diagnosis of chronic obstructive disease (n = 161), idiopathic pulmonary fibrosis (IPF; n = 50), cystic fibrosis (CF; n = 55), and others (n = 51). Samples were analyzed for Abs to SAgs by enzyme-linked immunosorbent assay, and DSA and cytokines by Luminex. The clinical diagnosis of PGD and bronchiolitis obliterans syndrome (BOS) was based on International Society for Heart and Lung Transplantation guidelines.
The overall prevalence of Abs to SAgs was 22.71%, including 18% in chronic obstructive pulmonary disease (p = 0.033), 34% in IPF (p = 0.0006), 29% in CF (p = 0.0023), and 19.6% in other diagnoses (p = 0.044). The incidence of PGD (88% vs 54%, p < 0.05), DSA (70% vs 45%, p < 0.01), and BOS (90% vs 38% (p < 0.001) after LTx was significantly higher in patients with pre-LTx Abs to SAgs than without. Pro-inflammatory cytokines (interleukin-1β, interleukin-17, and interferon-γ) were elevated in patients who had pre-LTx Abs to SAgs, along with a reduction in anti-inflammatory interleukin-10.
Patients with IPF and CF have the highest prevalence of Abs to SAgs. Patients with pre-existing Abs to SAgs are at increased risk for development of PGD, DSA, and BOS. Strategies to remove pre-existing Abs to SAgs should be considered to improve lung allograft outcome.
In this study, we investigated HLA class I and class II allele and haplotype frequencies in Emiratis and compared them to those of Asian, Mediterranean, and Sub-Saharan African populations.
...Two-hundred unrelated Emirati parents of patients selected for bone marrow transplantation were genotyped for HLA class I (
,
,
) and class II (
,
) genes using reverse sequence specific oligonucleotide bead-based multiplexing. HLA haplotypes were assigned with certainty by segregation (pedigree) analysis, and haplotype frequencies were obtained by direct counting. HLA class I and class II frequencies in Emiratis were compared to data from other populations using standard genetic distances (SGD), Neighbor-Joining (NJ) phylogenetic dendrograms, and correspondence analysis.
The studied HLA loci were in Hardy-Weinberg Equilibrium. We identified 17
, 28
, 14
, 13
, and 5
alleles, of which
(22.2%), -
(19.5%), -
(20.0%), -
(22.2%), and -
(32.8%) were the most frequent allele lineages.
~
(21.2%),
~
,
~
(11.7%),
~
(9.7%),
~
(7.5%), and
~
~
~
~
(4.2%) were the most frequent two- and five-locus HLA haplotypes. Correspondence analysis and dendrograms showed that Emiratis were clustered with the Arabian Peninsula populations (Saudis, Omanis and Kuwaitis), West Mediterranean populations (North Africans, Iberians) and Pakistanis, but were distant from East Mediterranean (Turks, Albanians, Greek), Levantine (Syrians, Palestinians, Lebanese), Iranian, Iraqi Kurdish, and Sub-Saharan populations.
Emiratis were closely related to Arabian Peninsula populations, West Mediterranean populations and Pakistanis. However, the contribution of East Mediterranean, Levantine Arab, Iranian, and Sub-Saharan populations to the Emiratis' gene pool appears to be minor.
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