Defective cytotoxicity of T lymphocytes in myelodysplastic syndrome.

Objective: The capacity of mononuclear blood cells to form autoreactive cytotoxic T lymphocytes was investigated in order to elucidate the mechanism of successful immunosuppressive therapy in some myelodysplastic syndrome (MDS) patients (autoreactivity studies). The failure in autoreactivity studies raised the question of alloreactive cytotoxic T lymphocyte formation in MDS (alloreactivity studies).

Materials And Methods: Sixteen MDS patients and relevant controls were examined.

[Auto- and alloreactivity of T lymphocytes in myelodysplastic syndrome].

Background: Successful therapy with ATG and cyclosporine A in some myelodysplastic syndrome (MDS) patients led us to study the existence of T cells attacking autologous hemopoietic cells. In our study, we attempted to give the direct prove of autoreactive T cells in MDS (autoreactivity analysis). Simultaneously, we analysed the capacity of MDS patients to respond to allogeneic cells from unrelated individuals (alloreactivity analysis).

Cytotoxic T lymphocyte precursor frequency analysis in the selection of HLA matched unrelated donors for hematopoietic stem cell transplantation: the correlation of CTLp frequency with HLA class I genotyping and aGVHD development.

The selection of human leukocyte antigen (HLA) compatible unrelated donors for hematopoietic stem cell transplantation (HSCT) is based on the direct genotyping of HLA class I and class II alleles (HLA-A, -B, -C, -DRB1, -DQB1 loci). The cellular test estimating the frequency of cytotoxic T lymphocyte precursors (CTLp) has been included into the selection procedure of unrelated donors to detect the class I alloreactivity and to predict acute graft versus host disease (aGVHD) occurrence and severity. The relationship between HLA-A, -B, -C high/medium resolution genotyping and CTLp activation was analysed in the cohort of 78 unrelated donor/patient pairs indicated for HSCT.

The relationship between HA-1 compatibility and the activation of helper T lymphocyte precursors.

The relationship between the compatibility in minor histocompatibility HA-1 antigen and the activation of helper (IL-2 producing) T lymphocyte precursors in vitro was studied in the group of 17 HLA-A2 positive HLA identical siblings. Although the number of pairs studied is still small, no correlation has been found between HA-1 compatibility and helper T lymphocyte precursors activation. The results presented here could suggest the possibility that the HTLp assay does not have to be a relevant parameter for the detection of HA-1 mismatches in HLA identical siblings.

Frequencies of HLA-DRB1, -DQB1 and -DPB1 alleles in Czech population.

The frequencies of phenotypes, alleles and allelic subtypes of DRB1 and DQB1 HLA loci in 420 unrelated individuals from the Czech population were determined. The frequencies of DPB1 alleles of the HLA locus were determined in 92 individuals. The assays were performed using the polymerase chain reaction (PCR) method or the restriction fragment length polymorphism (RFLP) analysis.