[Establish a Graded Method to Avoid HLA Class I Antibodies Corresponding Antigen and Combining HLAMatchmaker Application in Improving the CCI Value after Platelet Transfusion for Patients with IPTR].

OBJECTIVE: To establish a graded method to avoid mean fluorescence intensity (MFI) threshold of HLA Class I antibodies corresponding antigen, and the HLAMatchmaker program has been used to select the minimum mismatch value of donor-patient epitopes. Evaluate the application value of combining both methods in selecting HLA compatible platelets (PTL) for patients with immune platelet transfusion failure (IPTR) in improving platelet the corrected count increment (CCI). METHODS: A total 7 807 PLT cross-matching compatible were performed by the solid-phase red cell adherence (SPRCA) method for 51 IPTR patients. The Luminex single antigen flow cytometry was used to detect HLA Class I antibodies in patients, and detected the MFI value for different specificity antigens of HLA Class I antibodies, was graded into strong positive group (MFI>4 000, level 1), medium positive group (1 000< MFI≤4 000, 2), weak positive group (500< MFI≤1 000, 3), and one negative control group (MFI≤500). The results of 7 807 SPRCA their negative/positive reaction wells were enrolled and statistically analyzed in different grades and the four groups, the statistical differences between the four groups were compared. Multiple applications for the select HLA Class I compatible donor events were made for patients in two cases, and HLAMatchmaker program was used to calculate the number of HLA Class I epitopes mismatches between the donors and patients. The donor with the minimum number of epitopes mismatches was selected, while avoiding the corresponding antigens of HLA Class I antibodies in levels 1 and 2, the provision of HLA compatible platelets for IPTR. After the transfusions, the CCI value of the platelet transfusion efficacy evaluation index was calculated, and the clinical evaluation of the transfusion effect was obtained through statistical analysis. RESULTS: There were statistically significant differences in the positive results of SPRCA immunoassay among the strong positive group, medium positive group, and weak positive group of 51 IPTR patients with different specific of HLA -I class antibodies and corresponding antigens(all P <0.001). The positive results showed a range from high to low, with strong positive group>medium positive group>weak positive group. There were a statistical difference among between the strongly positive or moderately positive groups and the negative control group(P <0.001). There was no statistical difference between the weakly positive group and the negative control group(P >0.05). The strong positive group was set as the corresponding specific HLA Class I site corresponding antigen grade 1 avoidance threshold, the medium positive group as the grade 2 avoidance thresholds, and the weak positive group as the grade 3 avoidance threshold. In the case of donor platelet shortage, it is not necessary to avoid the weak positive group. Avoiding the strategy of donor antigens and HLAMatchmaker program scores ≤7 corresponding to HLA Class I antibodies of levels 1 and 2, with CCI values>4.5×109/L within 24 hours, can obtain effective clinical platelet transfusion conclusions. CONCLUSION: When selecting HLA Class I compatible donors for IPTR patients, the grading avoids HLA Class I antibodies corresponding to donor antigens, and the donor selection strategy with the minimum scores of HLAMatchmaker program is comprehensively selected. The negative result confirmed by platelet cross-matching experiments has certain practical application value for improving platelet count in IPTR patients.

[Expression and clonal proliferation of TCR Vbeta subfamilies of peripheral T-cells in acute myeloid leukemia patients].

This study was purposed to investigate the expression and clonal proliferation of receptor (TCR) Vbeta subfamilies of the T-cells in acute leukemic patients at different disease status (onset, complete remission or relapse) and to analyze the influence of the leukemic cell load on anti-leukemic effect of peripheral T-lymphocytes of the patients. Gene sequences of peripheral TCR Vbeta 24 families from 11 leukemic patients and 3 normal donors were expanded by RT-PCR. Genescan technique was applied to evaluate clonal expression of the TCRVbeta subfamilies, clonal characteristics of the CDR3 from peripheral blood of AML patients at different disease status. The application, clonal proliferation, cellular complexity of T-cells, and the variation of immunotypes of T-cells were compared. The results indicated that the lower and partial distribution of TCR Vbeta subfamily was found in all 11 patients when firstly diagnosed; the expression of TCR Vbeta subfamilies after induction in vitro increased; obvious elevation of TCR Vbeta subfamilies was observed in patients at complete remission although expression level was still lower than normal, whereas the significant descent of TCR Vbeta subfamilies was detected in 4 relapsed patients. Only 1 - 2 clonal proliferation of TCR Vbeta subfamilies existed in 9 out of 11 patients at initial diagnosis which increased at remission. The status of clonal proliferation of Vbeta subfamily T-cells continued regardless of any different disease status in most patients. There was an obvious decrease of CDR3 complexity at initial diagnosis or relapse, while CDR3 complexity would be partially improved at remission. It is concluded that the restrict distribution and expression of TCR Vbeta subfamilies were found in AML patients. Clonal proliferation of T-cells Vbeta subfamily continuously exists regardless of any different disease status in most patients. Some Vbeta subfamilies sustain clonal proliferation at different disease status. Some clonal proliferations of Vbeta subfamilies are associated with the effects of leukemic cells, CDR3 complexity obviously decreases under disease status which can be partially improved at remission.

[Large scale expansion of hematopoietic progenitor cells from umbilical cord blood by magnet stirred culture system].

The aim of this study was to expand hematopoietic progenitor cells at large scale by magnet stirred culture system. Mononuclear cell from umbilical cord blood were cultured in serum-free medium with stem cell factor, FIT-3 ligand and thrombopoietin. Firstly, the role of magnet on cell growth and colony-forming was studied by static culture on 0, 25 and 50 mT. Then the expansion multiple of cells, colony-forming and expression of surface markers were studied in magnet stirred culture by cell counting, colony-forming assay and flow cytometry. The results indicated that there was no difference in multiple of total cell expansion and numbers of hematopoietic colonies between 0, 25 and 50 mT groups and spinner groups (all p > 0.05). After 7 day cultures, the multiple of total cell expansion in magnet stirred culture was higher than that in static culture (p < 0.01). The numbers of CFU-GM (colony-forming unit-granulocyte/macrophage) and CFU-E (erythroid colony forming unit) in magnet stirred culture were higher than those in static culture, (p < 0.05). The primitive cells (CD34(+), CD34(+)/CD38(-) or CD133(+)) of the expanded cells in magnet stirred culture were less than those in static culture (p < 0.05). However, the CD184(+) or CD62L(+) expanded cells were more than that in static culture (p < 0.05). It is concluded that magnet stirred culture favors the expansion of hematopoietic progenitor cells. The results will be finally confirmed in further in vivo experiments and clinical applications.