A novel HLA-B allele, HLA-B*35:279, identified by sequencing-based typing in a Czech patient.

The identification of a novel HLA-B*35:279 allele in a Czech patient is described. This allele is identical to the B*35:03:01 variant except the G/A nucleotide exchange at position 652 of the HLA-B gene that corresponds to the amino acid substitution from valine to isoleucine in alpha 3 domain of the HLA-B antigen.

Somatic mutation in acute myelogenous leukemia cells imitate novel germline HLA-A allele: a case report.

A somatic mutation of the human leukocyte antigen (HLA)-A gene revealed in tumour cells of acute myelogenous leukemia (AML) is described. A patient with AML and her siblings were routinely typed for HLA in order to find a suitable donor for haematopoietic stem cell transplantation. Sequencing-based typing of the initial patient's sample characterized by high proportion of blasts revealed unknown G/A exchange at position 781 of the HLA-A gene (exon 4) associated with HLA-A*02:01 allele. Importantly, this G781A variant was completely absent in the patient's remission sample obtained after the clearance of blasts. Our results are a reminder that HLA mutations in tumour cells may interfere with routine HLA typing and should always be considered, namely, in patients with haematological malignancies.

A novel HLA-DRB1 allele, HLA-DRB1*13:116, identified by sequencing-based typing in a member of the Czech National Marrow Donor Registry.

We describe the identification of a novel HLA-DRB1 allele, DRB1*13:116, in a member of the Czech National Marrow Donor Registry. The novel allele differs from the known DRB1*13:17 variant by a nucleotide exchange at position 227 (T/A) of the coding HLA-DRB1 sequence, which causes an amino acid substitution (Phe47Tyr) in the HLA-DR beta 1 chain.

Association of IL-6 gene polymorphism with the outcome of allogeneic haematopoietic stem cell transplantation in Czech patients.

Interleukin-6 (IL-6) is an important pro-inflammatory mediator implicated in immune-mediated complications of allogeneic haematopoietic stem cell transplantation (aHSCT). In accord with previous reports, this preliminary study on 56 donor-recipient pairs revealed IL-6-174 single nucleotide polymorphisms as a risk factor for the development of acute graft-versus-host disease and decreased survival after aHSCT.

Class I typing by PCR-SSP in Olomouc.

In this article, methodical experience and population data are given for application of PCR-SSP/ARMS method (Phototyping) to HLA class I typing in Olomouc. Phototyping is reliable method suitable for typing of small to medium number of samples. Method is fast enough for use in on-call service, resolution is better than the level of good serology, and price of method is comparable with serology. Our experience and tips are described below. Population data of healthy unrelated individuals for HLA-A, -B, -Cw are given in the tables.

Association of IL6 and CCL2 gene polymorphisms with the outcome of allogeneic haematopoietic stem cell transplantation.

Various polymorphisms of non-HLA genes have recently been investigated as candidate risk factors in allogeneic haematopoietic SCT (aHSCT). Our study aimed at exploring possible associations of IL6 and CCL2 single nucleotide polymorphisms (SNP) with aHSCT outcome. A total of 166 HLA-identical aHSCT pairs recruited in were genotyped for IL6 -174 G/C, IL6 -597 G/A, CCL2 -2518 A/G and CCL2 -2076 A/T SNPs by PCR with sequence-specific primers (PCR-SSP). The association between IL6 -174 GG genotype and increased risk of acute GVHD was found in whole study group (P=0.03) and in the subgroup of related aHSCT (P=0.01), association between IL6 -597 GG genotype and the occurrence of acute GVHD was detected only in the related aHSCT pairs (P=0.02). Furthermore, reduction in OS was revealed among recipients possessing IL6 -174(*)G allele in the group of related aHSCT pairs (P=0.04). Presence of CCL2 -2076 TT genotype was associated with decrease of OS (P=0.04) and increase of TRM (P=0.02) in patients transplanted by related donor. These results, in the context of previous findings, suggest that IL6 gene polymorphisms may be associated with aHSCT outcome, particularly in patients transplanted from a related donor.

Distribution of 22 cytokine gene polymorphisms in the healthy Czech population.

Cytokine gene polymorphisms (CGP) have been implicated in the pathogenesis of immune-mediated diseases including transplant complications via their effect on cytokine production and regulation. This study aimed to determine population frequencies of selected cytokine single nucleotide polymorphisms in the healthy Czech population and compare them with the data from other selected European populations. CGP were genotyped by polymerase chain reaction with sequence-specific primers (PCR-SSP) using the Heidelberg kit in 120 unrelated Czech healthy individuals. Chi-squared analysis was used to test for a deviation from Hardy-Weinberg equilibrium. Allelic and genotype frequencies and carriage rates were determined for 22 CGP located within 13 cytokine genes in total. The frequencies observed in this study were similar to those available from the other two geographically close Central European centres, but they differed for several CGP from the data reported in south European populations. The data on the distribution of 22 CGP in the healthy Czech population reported here may be utilized to investigate possible associations of CGP with diseases or transplantation outcome.

A single amino acid exchange shifts the serological reactivity of the novel HLA-B*4442 allele product from HLA-B44 to HLA-B21.

A novel HLA-B (human leukocyte antigen-B) allele, HLA-B*4442, was identified both in a Czech patient with leukaemia and in his mother. The presence of a novel allele was initially suspected because conflicting results were obtained by serological and DNA typing techniques. The HLA typing using the polymerase chain reaction-sequence-specific primers (PCR-SSP) at the two-digit level indicated an allele belonging to the HLA-B*44 group, whereas serological typing indicated HLA-B21. Typing with PCR-sequence-specific oligonucleotides (PCR-SSO) resulted in a unique reaction pattern that could not be assigned to a known allele, PCR-SSP typing at the four-digit level did not match any known B*44 allele, either. The sequencing-based typing of the HLA-B locus then revealed the novel B*4442 allele that is identical with B*4405 except a single C-->G nucleotide exchange at position 572. This exchange results in an amino acid substitution from serine to tryptophan at position 167 of the expressed HLA-B protein. The B21 serological reactivity of the novel B*4442 allele product was confirmed by employing an additional serological panel of typing sera. Our findings support previous reports claiming that serine at the position 167 in the alpha-2 domain of the HLA-B protein is a major determinant of the HLA-B44(12) serological epitope.

A novel HLA-B*420502 allele identified by PCR-SSO/SSP routine typing and confirmed by Sequencing-based typing.

A novel human leukocyte antigen-B (HLA-B) allele, B*420502, was identified in a patient with leukemia (Caucasoid, Czech ancestry) and his mother during intrafamily search for the hematopoietic stem cell donor. The novel allele was initially detected by HLA typing at low resolution using both sequence specific primers and sequence specific oligonucleotides techniques that resulted in unique reaction patterns. The alleles of the HLA-B locus were separated by the haplotype-specific extraction technique. Sequencing of those alleles revealed a novel allele, B*420502, that is identical with B*420501 except a T-->G exchange (synonymous mutation) at position 618.

Non-expression of HLA-B*5111N is caused by an insertion into the cytosine island at exon 4 creating a frameshift stop codon.

The identification of the "blank" allele HLA-B*5111N, which was detected in German and Czech individuals, is described. In the pedigree analysis this new allele segregates with the serological haplotype HLA-A2; B-; DR4 which is frequent in Czech population. The non-expression of B*5111N is caused by the insertion of an additional cytosine molecule at the cytosine island between the nucleotides 621-626 (codons 183-185, first three codons of exon 4) leading to a frame shift that creates a stop codon at codon 196. This insertion may be explained either by conversion with the pseudogene HLA-J or by slipped-strand mispairing. In order not to overlook the presence of alleles with altered expression in case of hematopoietic stem cell transplantation, both serological and DNA-based typing should be performed (Note).

Characterization of a novel HLA-A*24 allele containing an HLA-A*03 sequence motif.

HLA-A*2418 is described for the first time. It segregates in a Mendelian fashion. Serological analyses indicate that the new allele encodes epitopes from both HLA-A9 and -A3 specificities. Results from nucleotide sequencing analyses of polymerase chain reaction (PCR) amplification products derived from genomic and cDNA are compatible with those findings.