ABSTRACT
The HLA-DPB1 locus has been demonstrated to have a significant role on patients' outcome after allogeneic HSCT, and the so-called T-cell epitope (TCE) algorithm has been incorporated in international guidelines for the selection of unrelated donors. The purpose of the present study is to measure, through a national survey conducted on behalf of the Associazione Italiana di Immunogenetica e Biologia dei Trapianti (AIBT), the extent of awareness and use of HLA-DPB1 TCE-based algorithms during the donor search. 89% of the HLA laboratories answered to a short questionnaire and the results showed a progressive increase of the laboratories typing DPB1 in patients and their potential donors during the search (from 44% to 79% during the 2010-2019 period) as well as the application of a TCE-based algorithm for the donor choice whenever possible (from 24% to 65% during the same period). The DP-permissiveness status is detailed in the official HLA typing report by 12%, 32% and 50% of laboratories in 2010, 2015 and 2019, respectively. The present data indicate an encouraging raise in the awareness of the HLA-DPB1 role in unrelated donor selection; noteworthy, mentioning the TCE-based permissiveness status in the HLA typing report of each potential unrelated donor represents a notable mean to raise awareness among transplant physicians and to support them in their task of choosing the best donor. Nonetheless, despite the compelling evidence of the predictive ability of TCE-based algorithms, further efforts are still needed to extend its application to all transplant centers in Italy.
Subject(s)
Epitopes, T-Lymphocyte , HLA-DP beta-Chains , Hematopoietic Stem Cell Transplantation , Algorithms , Alleles , Histocompatibility Testing , Humans , Italy , Surveys and Questionnaires , Unrelated DonorsABSTRACT
We describe here the sequences of 3 new HLA-DRB1 variants officially named DRB1*03:05:03, DRB1*11:10:02, and DRB1*14:86. These novel alleles have been detected in 3 Caucasoid individuals by sequence-based typing. The first and second alleles are the result of a silent mutation, which does not imply any amino acid change. The sequence of DRB1*14:86 exhibits a single nucleotide difference with the allele DRB1*14:01:01 at position 239.
Subject(s)
Genotyping Techniques/methods , HLA-DRB1 Chains/genetics , Sequence Analysis, DNA/methods , Alleles , Base Sequence , Humans , Molecular Sequence Data , Mutation , Polymerase Chain Reaction , Polymorphism, Genetic , Sequence Homology, Nucleic Acid , White People/geneticsABSTRACT
We report the identification of two novel human leucocyte antigen (HLA) in two Caucasian individuals. HLA-A*0343 differs from A*03010101 by four changes at nucleotides 411-414 (CCGG-->TGAA) and by a point mutation at position 418 (G-->C). These differences lead to two amino acid substitutions at codon 114, where arginine has changed into negatively charged glutamic acid, and at codon 116, where aspartic acid has changed into positively charged histidine. Molecular modeling showed that these changes have a profound influence on the overall charge of the F pocket of the groove, resulting in potentially important changes in the peptide repertoire. HLA-A*0345 was found in a hematological female patient candidate to bone marrow transplantation. This new variant differs from HLA-A*03010101 at position 845 (C-->A) encoding an amino acid change of threonine to asparagine at codon 258 located in the alpha3 domain. Molecular modeling does not suggest a substantial role of this substitutions on the interaction with beta2-microglobulin or CD8.
Subject(s)
Alleles , Computer Simulation , HLA-A Antigens/genetics , Mutation/genetics , Protein Interaction Domains and Motifs/genetics , Base Sequence , Bone Marrow Transplantation , Female , HLA-A Antigens/isolation & purification , HLA-A3 Antigen , Histocompatibility Testing , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology, Nucleic AcidABSTRACT
Although hepatitis C virus (HCV) is a recognized cause of circulating cryoglobulins, the role of human immunodeficiency virus (HIV) in the pathogenesis of cryoglobulinemia has not been investigated extensively. To evaluate the prevalence of circulating cryoglobulins and to assess the relationship with clinical and virological parameters, 162 HIV-positive subjects (84 anti-HCV(+)) were tested for cryoglobulins, C3, C4, RF, autoantibodies, HIV-viral titer, and CD4(+) count. Anti-HCV-positive subjects were tested for HCV-RNA, HCV-viral titer, and HCV genotype. All patients were examined for the presence of signs or symptoms of vasculitis and tested for cryoglobulins using a standard biochemical assay. Cryoglobulins were found in 30 (18.5%) cases. Of the 30 positive cases, 29 (96.7%) were anti-HCV-positive and 28 (93.3%) HCV-RNA-positive. The presence of cryoglobulins was significantly associated (P < 0.01) with HCV-RNA positivity (OR = 27), liver cirrhosis (OR = 16), decreased levels of C3 (OR = 8.6), C4 (OR = 13.6), increased levels of IgG and IgM (OR = 6.1 and 7.9, respectively), and RF positivity (OR = 6.3), but was unrelated to CD4(+) cell count, HIV viral load, diagnosis of AIDS, HCV viral load and the presence of autoantibodies. Interestingly, the presence of cryoglobulins was not significantly associated with signs and symptoms commonly associated with cryoglobulinemia. In conclusion, HIV infection does not seem to play a significant role in the production of circulating cryoglobulins, which strongly correlates with HCV co-infection and liver cirrhosis. Typical signs and symptoms of cryoglobulinemia do not correlate with the detection of circulating cryoglobulins in HIV and HCV patients.
