Identification of the novel HLA-DPA1*02:110:02 allele by next-generation sequencing

The novel HLA-DPA1*02:110:02 allele differs from HLA-DPA1*02:01:01:06 by one nucleotide substitution in exon 4.

Characterization of the novel HLA-DRB3*02:192 allele by sequencing-based typing

HLA-DRB3*02:192 differs from DRB3*02:02:01:02 by one nucleotide substitution in codon 204 in exon 4.

Characterization of the novel HLA-DQA1*05:05:14 allele by sequencing-based typing

HLA-DQA1*05:05:14 differs from HLA-DQA1*05:05:01:04 by one nucleotide substitution in codon -8 in exon 1.

A new HLA-B allele, HLA-B*07:422

The novel allele HLA-B*07:422 differs from HLA-B*07:02:01:01 by one nucleotide substitution in exon 4.

Characterization of the novel HLA-DQA1*01:02:11 allele by sequencing-based typing

HLA-DQA1*01:02:11 differs from HLA-DQA1*01:02:01:10 by one nucleotide substitution in codon 201 in exon 4.

A new HLA-B allele, HLA-B*35:481

The novel allele HLA-B*35:481 differs from HLA-B*35:05:01 by two nucleotide substitution in exon 3.

Characterization of the novel HLA-DQA1*01:58 allele by sequencing-based typing

HLA-DQA1*01:58 differs from HLA-DQA1*01:02:01:06 by one nucleotide substitution in codon 46 in exon 2.

A new HLA-DQA1 allele, HLA-DQA1*01:26

The novel allele HLA-DQA1*01:26 differs from HLA-DQA1*01:01:01:01 by one nucleotide substitution in exon 2.

Characterization of the novel HLA-DRB3*02:96 allele by sequencing-based typing

HLA-DRB3*02:96 differs from HLA-DRB3*02:02:01:01 by one nucleotide substitution in codon 189 in exon 4.

Characterization of the novel HLA-C*07:708 allele by sequencing-based typing

HLA-C*07:708 differs from HLA-C*07:01:01:01 by one nucleotide substitution at codon 258 in exon 4.

The novel HLA-DRB3*02:02:11 allele identified in an Italian individual

HLA-DRB3*02:02:11 differs from HLA-DRB3*02:02:01:01 by a single synonymous substitution in exon 3'.

Split chimerism between nucleated and red blood cells after bone marrow transplantation for haemoglobinopathies

Previous studies have shown that a stable presence of both donor and recipient haematopoietic derived cells after allogeneic haematopoietic stem cell transplantation (HSCT) occurs in approximately ten percent of the patients affected by β-Thalassemia. Once achieved this condition, defined as persistent mixed chimerism (PMC), the patients do not require additional red blood cells (RBCs) support and, regardless of the presence in some cases of an extremely low percentage of donor-derived nucleated cells, they are clinically cured by an incomplete, but functional graft. Most of the published papers have, however, investigated the impact of donor engraftment in the nucleated cells rather than in the mature erythrocytes. We have recently published a paper showing that in four long-term transplanted patients affected by hemoglobinopathies, characterized by the presence of few donor engrafted nucleated cells-both in the peripheral blood and in the bone marrow-the majority of the erythrocytes were of donor origin. Moreover we showed that the proportion of donor-derived erythroid precursors, determined by analyzing singularly picked-up burst-forming unit erythroid colonies, was equivalent to that observed in the mature nucleated cells rather than in the red blood cells. These results suggest that in patients characterized by the presence of PMC after HSCT a selective advantage of the donor erythroid precursors maturation might successfully contrast the problems bound to the recipient ineffective erythropoiesis. When genetically modified HSCT will be a possible option for treating Thalassemia Major, the co-existence of the repaired cells with those still expressing the genetic defect will be an expected scenario, not in an allogeneic, but in an autologous environment.

Identification of the novel allele, HLA-A*02:653, in an Italian patient

HLA-A*02:653 differs from A*02:01:01:01 by a C to T substitution in exon 2.

Identification of the new C*07:555 allele in an unrelated donor for HSCT

HLA-C*07:555 differs from C*07:01:01:01 by a C to G substitution in exon 2.

Characterization of the novel HLA-C*02:106 allele in a hematopoietic stem cell volunteer donor

HLA-C*02:106 allele differs from C*02:02:02:01 by a C to T substitution in exon 4.

Sequence-based typing characterization of the novel HLA-DRB3*01:16 allele, identified in an Italian family

The novel DRB1*01:16 allele differs for G to T substitution at position 595 from DRB3*01:01P.

The novel HLA-A*03:143 allele, identified by sequence-based typing in an Italian family

HLA-A*03:143 has one nucleotide change from A*03:01: 01:01 at nt 406 from G to C, resulting in an amino acid change at codon 112 of exon 3 from Gly to Arg.

Characterization of the novel HLA-C*07:195 allele in an Italian hematopoietic stem cell volunteer donor, detected by sequence-based typing

The new allele shows one nucleotide change from C*07:02:01:01 at 351 nt from C to A, resulting in an amino acid change at codon 93 of exon 3 from H to Q.

Identification of the new HLA-A*31:48 allele in an Italian patient

Human leukocyte antigen (HLA) class I sequence-based typing (SBT) for hematopoietic unrelated donor searching in an Italian Caucasian patient showed the presence of a novel HLA-A allele defined as A*31:48. HLA-A*31:48 has one nucleotide change from A*31:01:02 at nt 727 from C to T, resulting in an amino acid change at codon 219 of exon 4 from Arg to Trp.

Quantitatively different red cell/nucleated cell chimerism in patients with long-term, persistent hematopoietic mixed chimerism after bone marrow transplantation for thalassemia major or sickle cell disease

BACKGROUND

Persistent mixed chimerism represents a state in which recipient and donor cells stably co-exist after hematopoietic stem cell transplantation. However, since in most of the studies reported in literature the engraftment state was observed in the nucleated cells, in this study we determined the donor origin of the mature erythrocytes of patients with persistent mixed chimerism after transplantation for hemoglobinopathies. Results were compared with the engraftment state observed in singly picked out burst-forming unit - erythroid colonies and in the nucleated cells collected from the peripheral blood and from the bone marrow.

DESIGN AND METHODS

The donor origin of the erythrocytes was determined analyzing differences on the surface antigens of the erythrocyte suspension after incubation with anti-ABO and/or anti-C, -c, -D, -E and -e monoclonal antibodies by a flow cytometer. Analysis of short tandem repeats was used to determine the donor origin of nucleated cells and burst-forming unit - erythroid colonies singly picked out after 14 days of incubation.

RESULTS

The proportions of donor-derived nucleated cells in four transplanted patients affected by hemoglobinopathies were 71%, 46%, 15% and 25% at day 1364, 1385, 1314 and 932, respectively. Similar results were obtained for the erythroid precursors, analyzing the donor/recipient origin of the burst-forming unit - erythroid colonies. In contrast, on the same days of observation, the proportions of donor-derived erythrocytes in the four patients with persistent mixed chimerism were 100%, 100%, 73% and 90%. Conclusions Our results showed that most of the erythrocytes present in four long-term transplanted patients affected by hemoglobinopathies and characterized by the presence of few donor engrafted nucleated cells were of donor origin. The indication that small proportions of donor engrafted cells might be sufficient for clinical control of the disease in patients affected by hemoglobinopathies is relevant, although the biological mechanisms underlying these observations need further investigation.

Identification of a novel HLA-B*07 allele in an Iranian family: B*0769

New allele B*0769 showed one nucleotide difference with B*0732 at codon 272 (TTC-->TGC).