T Cell and Cytokine Dynamics in the Blood of Patients after Hematopoietic Stem Cell Transplantation and Multipotent Mesenchymal Stromal Cell Administration.

Multipotent mesenchymal stromal cells (MSCs) are currently under intensive investigation for the treatment and prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), owing to their substantial immunomodulatory properties. The responses of recipients to MSC infusion following allo-HSCT are not yet well understood. T cells are central to the adaptive immune system, protecting the organism from infection and malignant cells. Memory T cells with different phenotypes, gene expression profiles, and functional properties are critical for immune processes regulation. The aim of this study was to study the dynamics of memory T cell subpopulations and cytokines in the blood of allo-HSCT recipients after MSC administration. In clinical trial NCT01941394, patients after allo-HSCT were randomized into 2 groups, one receiving standard GVHD prophylaxis and the other also receiving MSC infusion on the day of leukocyte recovery to 1000 cells/µL (engraftment, day E0). Blood samples of patients from both groups were analyzed on days E0, E+3, and E+30. T cell subpopulations were studied by flow cytometry, and cytokine concentrations were evaluated by the Bio-Plex Pro Human Cytokine Panel. Administration of MSCs to patients on day E0 did not affect the overall dynamics of restoration of absolute numbers and proportions of T and B lymphocytes after 3 and 30 days. At 3 days after MSC injection, only the numbers of CD8+ effector cells (CD8+TE, CD8+TM, and CD8+EM) were found to increase significantly. A significant increase in the number of CD4+ cells after 30 days compared to day E0 was observed only in patients who received MSCs, indicating faster recovery of the CD4+ cell population following MSC injection. An increase in CD8+ cell number by day E+30 was significant regardless of MSC administration. To characterize the immune status of patients following allo-HSCT in more detail, changes in the cytokine concentration in the peripheral blood of patients on days E0, E+3, and E+30 after MSC administration were investigated. On day E+30, significant increases in the numbers of CD4+CM and activated CD4+CD25+ cells were observed. The concentrations of proinflammatory and anti-inflammatory cytokines IL-6, IL-8, IL-17, TNF-α, and IFN-γ were increased significantly in patients injected with MSCs. Analysis of growth factor levels showed that in the group of patients who received MSCs, the concentrations of G-CSF, GM-CSF, PDGFbb, FGFb, and IL-5 increased by day E+30. Among the cytokines involved in regulation of the immune response, concentrations of IL-9, eotaxin, IP-10, MCP-1, and MIP-1a were increased after 30 days irrespective of MSC administration. The administration of MSCs exerts a positive effect on the restoration of T cell subpopulations and immune system recovery in patients after allo-HSCT.

Bowel wall thickness is a strong predictor of steroid-refractory acute graft-versus-host disease with gut involvement after allo-HSCT.

OBJECTIVE: Acute graft-versus-host-disease (aGVHD) develops in 10-80% of allo-HSCT patients. More than half of all aGVHD cases are refractory to first-line therapy with steroids. We hypothesized that bowel wall thickness at the time of aGVHD diagnosis could be an early sign of steroid-refractory aGVHD with gut involvement. METHOD: Our prospective study included 85 patients with hematological malignancies who had undergone allo-HSCT. We used an inexpensive, widespread and simple method of transabdominal ultrasonography to examine bowel wall thickness in patients suspected to have gut aGVHD. RESULTS: Descending colon wall thickness was significantly greater in patients with gut aGVHD later found to be steroid-refractory than in patients with steroid-sensitive gut aGVHD, with AUC-0.73 (95% CI 0.58-0.87, p = 0.013). We showed that bowel wall thickness could predict the steroid-refractoriness of aGVHD. CONCLUSION: Transabdominal ultrasonography could be used as a marker of steroid-refractory aGVHD with gut involvement after allo-HSCT.

Humoral Effect of a B-Cell Tumor on the Bone Marrow Multipotent Mesenchymal Stromal Cells.

The properties of bone marrow (BM)-derived multipotent mesenchymal stromal cells (MSCs) are altered in the patients with the diffuse large B cell lymphoma (DLBCL) without BM involvement. It was suggested that plasma from the patients contains soluble factors that affect MSCs. Plasma and BM-derived MSCs from the DLBCL patients at the onset of the disease and one month after the end of treatment were studied. Concentration of the plasma cytokines and gene expression in the MSCs were evaluated by the Bio-Plex Pro Human Cytokine Panel kit to measure 27 analytes and real-time PCR. Plasma and MSCs from the healthy donors were used as controls. Analysis of cytokines in the plasma from healthy donors and patients before and one month after the end of treatment revealed significant differences in the concentration of 14 out of 27 cytokines. Correlations between the levels of secreted cytokines were altered in the plasma from patients indicating that the immune response regulation was disturbed. Cultivation of the MSCs from the healthy donors in the medium supplemented with the plasma from patients led to the changes in the MSC properties, similar to those observed in the MSCs from patients. The BM-derived MSCs were shown to participate in the humoral changes occurring in the DLBCL patients. For the first time, it was shown that the precursors of the stromal microenvironment - multipotent mesenchymal stromal cells - are altered in the patients with DLBCL without bone marrow involvement due to the humoral effect of the tumor and the response of organism to it. Comprehensive analysis of the results shows that, when remission is achieved in the patients with DLBCL, composition of the plasma cytokines normalizes, but does not reach the level observed in the healthy donors. The discovery of a new aspect of the effect of the tumor B-cells on the organism could help to reveal general regularities of the humoral effect of various tumors on the bone marrow stromal cells.

HLA-A*24:521 and HLA-B*13:152 identified by next-generation sequencing in Russian bone marrow donors.

Two novel alleles, HLA-A*24:521 and HLA-B*13:152, are characterized.

Two novel HLA alleles identified in Russian bone marrow donors: HLA-A*02:957 and -C*12:03:67.

Characterization of two novel HLA class I alleles, A*02:957 and C*12:03:67.

Diagnostic significance of flow cytometry scales in diagnostics of myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) can present a challenge for clinicians. Multicolor flow cytometry (MFC) can aid in establishing a diagnosis. The aim of this study was to determine the optimal MFC approach for MDS. METHODS: The study included 102 MDS (39 low-grade MDS), 83 cytopenic patients without myeloid neoplastic disorders (control group), and 35 healthy donors. Bone marrow was analyzed using a six-color MFC. Analysis was conducted according to the "Ogata score," "Wells score," and the integrated flow cytometry (iFC) score. RESULTS: The respective sensitivity and specificity values were 77.5% and 90.4% for the Ogata score, 79.4% and 81.9% for the Wells score, and 87.3% and 87.6% for the iFC score. Specificity was not 100% due to deviations of MFC parameters in the control group. Patients with paroxysmal nocturnal hemoglobinuria (PNH) had higher levels of CD34+ CD7+ myeloid cells than donors. Aplastic anemia and PNH were characterized by a high proportion of CD56+ cells among CD34+ precursors and neutrophils. The proportion of MDS-related features increased with the progression of MDS. The highest number of CD34+ blasts was found in MDS with excess blasts. MDS with isolated del(5q) was characterized by a high proportion of CD34+ CD7+ cells and low granularity of neutrophils. In 39 low-grade MDS, the sensitivities were 53.8%, 61.5%, and 71.8% for Ogata score, Wells score, and iFC, respectively. CONCLUSION: The results support iFC as a useful diagnostic tool in MDS.

Immunophenotypic characteristics of multipotent mesenchymal stromal cells that affect the efficacy of their use in the prevention of acute graft vs host disease.

BACKGROUND: Multipotent mesenchymal stromal cells (MSCs) are widely used in the clinic due to their unique properties, namely, their ability to differentiate in all mesenchymal directions and their immunomodulatory activity. Healthy donor MSCs were used to prevent the development of acute graft vs host disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT). The administration of MSCs to patients was not always effective. The MSCs obtained from different donors have individual characteristics. The differences between MSC samples may affect their clinical efficacy. AIM: To study the differences between effective and ineffective MSCs. METHODS: MSCs derived from the bone marrow of a hematopoietic stem cells donor were injected intravenously into allo-BMT recipients for GVHD prophylaxis at the moment of blood cell reconstitution. Aliquots of 52 MSC samples that were administered to patients were examined, and the same cells were cultured in the presence of peripheral blood mononuclear cells (PBMCs) from a third-party donor or treated with the pro-inflammatory cytokines IL-1ß, IFN and TNF. Flow cytometry revealed the immunophenotype of the nontreated MSCs, the MSCs cocultured with PBMCs for 4 d and the MSCs exposed to cytokines. The proportions of CD25-, CD146-, CD69-, HLA-DR- and PD-1-positive CD4+ and CD8+ cells and the distribution of various effector and memory cell subpopulations in the PBMCs cocultured with the MSCs were also determined. RESULTS: Differences in the immunophenotypes of effective and ineffective MSCs were observed. In the effective samples, the mean fluorescence intensity (MFI) of HLA-ABC, HLA-DR, CD105, and CD146 was significantly higher. After MSCs were treated with IFN or cocultured with PBMCs, the HLA-ABC, HLA-DR, CD90 and CD54 MFI showed a stronger increase in the effective MSCs, which indicated an increase in the immunomodulatory activity of these cells. When PBMCs were cocultured with effective MSCs, the proportions of CD4+ and CD8+central memory cells significantly decreased, and the proportion of CD8+CD146+ lymphocytes increased more than in the subpopulations of lymphocytes cocultured with MSC samples that were ineffective in the prevention of GVHD; in addition, the proportion of CD8+effector memory lymphocytes decreased in the PBMCs cocultured with the effective MSC samples but increased in the PBMCs cocultured with the ineffective MSC samples. The proportion of CD4+CD146+ lymphocytes increased only when cocultured with the inefficient samples. CONCLUSION: For the first time, differences were observed between MSC samples that were effective for GVHD prophylaxis and those that were ineffective. Thus, it was shown that the immunomodulatory activity of MSCs depends on the individual characteristics of the MSC population.

The novel HLA-A*26:01:64 allele, identified by next-generation sequencing in a bone marrow donor of Bashkir origin.

HLA-A*26:01:64 has one nucleotide difference from HLA-A*26:01: 01:01 at gDNA position 989 (G→A).

Can Less Intensive Chemotherapy and an Autotransplant Cure Adult T-Cell Acute Lymphoblastic Leukemia?

T-cell acute lymphoblastic leukemia (T-ALL) is a rare disease usually treated with intensive, high-dose consolidation chemotherapy followed by an allotransplant in a substantial number of patients. The data of the RALL-2009 study on 125 adult T-ALL patients suggest that similar total chemotherapy doses given less intensively over a longer interval without interruptions and with an auto- rather than an allotransplant produce outcomes like current more intensive protocols and an allotransplant: 9-year cumulative incidence of relapse (CIR), leukemia-free survival (LFS), and survival were 24% (95% CI 16-33%), 70% (95% CI 59-79%) and 62% (95% CI 51-72%). In a landmark analysis, subjects achieving a complete remission and receiving an autotransplant had a lower 9-year CIR (9% [95% CI 2-22%] vs. 29% [95% CI 16-43%]; p = 0.0076) and better LFS (91% [95% CI 79-98%] vs. 58% [95% CI 41-74%]; p = 0.0009) and survival (92% [95% CI 77-99%] vs. 60% [95% CI 44-77%]; p = 0.001) compared with subjects not receiving an autotransplant. In a multivariate analysis, white blood cells ≥100 × 109/L at study entry were significantly associated with worse LFS (HR = 2.842 [95% CI 1.131-7.143]; p = 0.0263) and survival (HR = 6.085 [95% CI 1.918-19.3]; p = 0.0022) because of more early deaths (HR = 2.42 [95% CI 1.04-5.67]; p = 0.041). Receiving an autotransplant correlated with a lower CIR (HR = 0.23 [95% CI 0.07-0.73]; p = 0.0136) and better LFS (HR = 0.27 [95% CI 0.08-0.85]; p = 0.0256) and survival (HR = 0.158 [95% CI 0.045-0.550]; p = 0.0037).

Allele and haplotype frequencies of HLA-A, -B, -C, -DRB1, -DQB1 in Northern Ossetians from Vladikavkaz, Russia.

This report shows the HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in a population of 127 healthy Ossetian donors of blood marrow from Vladikavkaz, Russia. First- and second-field (for HLA-C locus) HLA genotyping was performed by polymerase chain reaction sequence-specific priming and/or oligonucleotide probes. Statistical analysis were performed using gene counting and Arlequin software packages. There was no deviation from Hardy-Weinberg equilibrium for all tested loci. The HLA genotypic and haplotypic data of the Ossetians reported here are available in free access at the Allele Frequencies Net Database (http://www.allelefrequencies.net). This data can serve as a reference database for further HLA-based studies in population genetics.

Recovery of Donor Hematopoiesis after Graft Failure and Second Hematopoietic Stem Cell Transplantation with Intraosseous Administration of Mesenchymal Stromal Cells.

Multipotent mesenchymal stromal cells (MSCs) participate in the formation of bone marrow niches for hematopoietic stem cells. Donor MSCs can serve as a source of recovery for niches in patients with graft failure (GF) after allogeneic bone marrow (BM) transplantation. Since only few MSCs reach the BM after intravenous injection, MSCs were implanted into the iliac spine. For 8 patients with GF after allo-BMT, another hematopoietic stem cell transplantation with simultaneous implantation of MSCs from their respective donors into cancellous bone was performed. BM was aspirated from the iliac crest of these patients at 1-2, 4-5, and 9 months after the intraosseous injection of donor MSCs. Patients' MSCs were cultivated, and chimerism was determined. In 6 out of 8 patients, donor hematopoiesis was restored. Donor cells (9.4 ± 3.3%) were detected among MSCs. Thus, implanted MSCs remain localized at the site of administration and do not lose the ability to proliferate. These results suggest that MSCs could participate in the restoration of niches for donor hematopoietic cells or have an immunomodulatory effect, preventing repeated rejection of the graft. Perhaps, intraosseous implantation of MSCs contributes to the success of the second transplantation of hematopoietic stem cells and patient survival.

Human Herpesvirus Type 8-positive Multicentric Castleman Disease.

Castleman disease (CD) is rare lymphoproliferative disorder with local lesionsor with multiple lessions (multicentric CD [MCD]-usually with plasma cell or mix cell morphology). Patients with human herpesvirus (HHV) type 8-positive MCD were included in a separate group owing to its extremely aggressive course and the high risk of transformation into HHV8(+) plasmablastic lymphoma. At our hematologic center, from 1996 to the present, the clinical and morphologic features of 87 patients with CD were analyzed. Immunohistochemical examination revealed DNA HHV8(+) lymph node tissue in patients with plasma cell and mixed cell morphology. In 45 patients, plasma cell or mixed cell variant CD was diagnosed. In 21 patients (8%), the manifestation of CD was local and in 29 (9%), it was multicentric. HHV8 was identified in only 6 cases (23.1%) of MCD (5 men and 1 woman, with a median age of 48.2 years; range, 36-77 years). The median follow-up point was 39.2 months. In 4 patients, the mixed cell variant was diagnosed and in 2, the plasma cell variant was diagnosed. In all the patients, constitutional symptoms, generalized lymphadenopathy, and hepatosplenomegaly were detected. Various laboratory changes were observed, but the most significant were anemia, thrombocytopenia, hypergammaglobulinemia, M-component, increased erythrocyte sedimentation rate, and circulating immune complexes. In 2 cases of HHV8(+) CD, MCD was combined with autoimmune hemolytic anemia and in 2 cases with non-Hodgkin lymphoma. At the last follow-up point, 2 patients were still alive after CHOP (cyclophosphamide, prednisone, Adriamycin, vincristine) and R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate [Oncovin], prednisone) therapy with rituximab maintenance. HHV8(+) MCD results in aggressive multiorgan lesions and pronounced changes in laboratory test results. It is characterized by an unfavorable prognosis with a high risk of transformation to plasmablastic lymphoma and a lethal outcome. Timely chemotherapy for patients with HHV8(+) MCD can result in remission and prolong life.