In vivo and in vitro effects of cord blood hematopoietic stem and progenitor cell (HSPC) expansion using valproic acid and/or nicotinamide.

BACKGROUND: High self-renewal capacity and most permissive nature of umbilical cord blood (CB) results with successful transplant outcomes but low hematopoietic stem and progenitor cell (HSPC) counts limits wider use. In order to overcome this problem ex vivo expansion with small molecules such as Valproic acid (VPA) or Nicotinamide (NAM) have been shown to be effective. To the best of our knowledge, the combinatory effects of VPA and NAM on HSPC expansion has not been studied earlier. The aim of this study was to analyze ex vivo and in vivo efficacy of VPA and NAM either alone or in combination in terms of expansion and engraftment. METHODS: A total of 44 CB units were included in this study. To determine the ex vivo and in vivo efficacy, human CB CD34+ cells were expanded with VPA and/or NAM and colony forming unit (CFU) assay was performed on expanded HSPC. Xenotransplantation was performed simultaneously by intravenous injection of expanded HSPC to NOD-SCID gamma (NSG) mice (n = 22). Significance of the difference between the expansion groups or xenotransplantation models was analyzed using t-test, Mann-Whitney, ANOVA or Kruskal-Wallis tests as appropriate considering the normality of distributions and the number of groups analyzed. RESULTS: In vitro CD34+ HSPC expansion fold relative to cytokines-only was significantly higher with VPA compared to NAM [2.23 (1.07-5.59) vs 1.48 (1.00-4.40); p < 0.05]. Synergistic effect of VPA+NAM has achieved a maximum relative expansion fold at 21 days (D21) of incubation [2.95 (1.00-11.94)]. There was no significant difference between VPA and VPA+NAM D21 (p = 0.44). Fold number of colony-forming unit granulocyte-macrophage (CFU-GM) colonies relative to the cytokine-only group was in favor of NAM compared to VPA [1.87 (1.00-3.59) vs 1.00 (1.00-1.81); p < 0.01]. VPA+NAM D21 [1.62 (1.00-2.77)] was also superior against VPA (p < 0.05). There was no significant difference between NAM and VPA+NAM D21. Following human CB34+ CB transplantation (CBT) in the mouse model, fastest in vivo leukocyte recovery was observed with VPA+NAM expanded cells (6 ± 2 days) and the highest levels of human CD45 chimerism was detectable with VPA-expanded CBT (VPA: 5.42 % at day 28; NAM: 2.45 % at day 31; VPA+NAM 1.8 % at day 31). CONCLUSION: Our study results suggest using VPA alone, rather than in combination with NAM or NAM alone, to achieve better and faster expansion and engraftment of CB HSPC.

Determination of the Relationship Between the Development and Recurrence of Subacute Thyroiditis and Human Leukocyte Antigen Subtypes.

Background: There are several studies investigating the role of human leukocyte antigens (HLA) in the development and recurrence of subacute thyroiditis (SAT). The HLA subtypes associated with SAT were usually determined in a population-based manner and HLA-B*35, HLA-B*18:01, HLA-C*04:01, and HLA-DRB1*01 were detected to play a role in the disease susceptibility and prognosis. The aim of this study was to determine HLA alleles associated with the tendency of recurrence and prevention of SAT within the Turkish population. Methods: This prospective study was conducted with 51 SAT patients and 720 healthy bone marrow donor volunteers. HLA-A, -B, -C, -DRB1, and -DQB1 were genotyped using next-generation sequencing. Results: The frequency of HLA-A*02:09, HLA-B*35:01/35:02/35:03, HLA-C*04:01, HLA-DRB1*12:01, and DRB1*13:03 were associated with an increased risk of SAT development (Odds Ratio: 22.4, 9.5, 10.3, 4.2, and 3.5, respectively). While HLA-A*02:09, HLA-B*35:01, HLA-B*44:02 HLA-C*07:18, and HLA-C*16:04 were associated with nonrelapsing SAT, HLA-DR*12:01was associated with relapsing SAT. HLA-B*35:02, HLA-B*35:03, and HLA-C*04:01 were more frequent both in relapsing and nonrelapsing groups according to control group. The frequency of HLA-B*18:01, reported as a risk factor previously, was similar in the SAT and control groups (p = 0.959). HLA-DRB1*11:01 was associated with a lower risk of SAT development. Conclusions: Along with -B*358 and -C*04, HLA-A*02:09 was detected as an important risk factor for SAT development in our population. HLA-DRB1*11:01 appears to be the protective HLA subtype against SAT. HLA-A*02:09, HLA-B*35:01, HLA-B*44:02, HLA-C*07:18, HLA-C*16:04, HLA-DQ*06:03, and HLA-DR*12:01 subtypes can establish a tendency to relapsing or nonrelapsing SAT.

A Novel Hypothesis: Certain KIR/Cognate Ligand Containing Genotypes Differ in Frequency Among Patients With Myeloma and Have an Effect on Age of Disease Onset.

BACKGROUND: Natural killer (NK) cells are known to have cytotoxic effects mediated through killer immunoglobulin-like receptors (KIRs) and their cognate ligands. Role of KIRs in myeloma is yet unresolved. PATIENTS AND METHODS: KIR genotypes and ligands of 204 newly diagnosed MM patients are compared with 424 healthy subjects. Statistical analysis included t-test, chi-square and binary logistic regression. RESULTS: KIR ligands were significantly more (C2C2: 27.5% vs 15.1%; OR 2.128; 95% CI, 1.417-3.196; P < .001) or less (C1C2: 40.2% vs 51.9%; OR 0.623; 95% CI, 0.444-0.874; P = .006) frequent among MM. Co-occurrence of genotype AA with C2C2 was also higher in frequency among MM (OR 2.509; 95% CI, 1.171-5.378; P = .015) likewise cAB1 with C1C2 was less frequent (OR 0.553; 95% CI, 0.333-0.919; P = .021). Genotypes AA with C1C1, cAB1 with C1C2 or C1C2 alone were associated with a delay (median age: 61 [48-73]; P = .044; 62 [31-81]; P = .030 or 59 [31-85]; P = .028), but AA with C2C2 with an earlier age of onset (48 [29-77]; P = .042). In multivariate analysis including R-ISS, light chain, KIR genotype/ligands; ligand C1C2 (P = .02) and genotype AA-C1C1 (P = .037) were independently associated with age of onset ≥60. CONCLUSION: C1C2 and C2C2 alone or in combination with KIR genotype (cAB1 and AA, respectively), is observed in less or higher frequency among MM cases and associated with delayed/earlier age of onset, respectively. Genotype AA-C1C1 although in similar frequency between patients and healthy subjects, is also associated with delay. To our knowledge, this is the first study demonstrating an association between KIR and MM onset age, independent from R-ISS or light chain type.

Role of large unstained cells in predicting successful stem cell collection in autologous stem cell transplantation.

INTRODUCTION: Sufficient stem cell collection is mandatory for Autologous stem cell transplantation (ASCT). Peripheral CD34+ stem CD34 + stem cell counting by flow cytometry is the gold standard method in both the predicting and timing of successful stem cell collection. Large unstained cells (LUC) are large peroxidase-negative cells that are displayed on certain automatic cell counters and present large lymphocytes, virocytes, blasts, abnormal cells and hematopoietic stem cells. In this study, we evaluated the role of LUC parameters in the timing and prediction of successful stem cell collection. METHODS: Patients with a diagnosis of multiple myeloma, lymphoma and testis tumor who proceed to ASCT were included in this study. Preapheresis LUC parameters were analyzed with Siemens ADVIA® 2120i system., Kruskal Wallis, Mann-Whitney U, Spearman Rho and receiver-operator curve (ROC) tests were used for analyses. RESULTS: Ninety patients were evaluated. Peripheral CD34 + cell count was positively correlated with both LUC count (p = 0014) and LUC percentage (p = 0,01). LUC percentage in peripheral blood was positively correlated with mobilized stem cell count in the yield (p = 0.003). We found a LUC count of > 0.485 × 109/L as a cut-off value for detecting > 20 × 106/L CD34 +cells in the peripheral blood with a sensitivity of 64.6% and specificity of 75%. We defined > 2.15% as a cut-off value for LUC percentage to collect > 5 × 106/kg of stem cells with a sensitivity of 64% and specificity of 63%. Additionally, total nucleated cell (TNC) count was negatively correlated with LUC percentage (p = 0.014) and positively correlated with LUC count (p = 0.001). CONCLUSION: LUC parameters are readily available, simple and cheap tools that can be useful in both timing of CD34 count by flow cytometry in peripheral blood and in the prediction of successful mobilization. LUCs can also be an indicator of graft composition.

Effect of CD34⁺ Total/Myeloid CD34⁺ Cell Progenitors and B-Lymphoid Progenitors Within the Bone Marrow Grafts on the Hematopoietic Recovery After Hematopoietic Stem Cell Transplantation.

OBJECTIVES: The influence of CD34⁺ cells on transplant outcomes following hematopoietic stem cell transplantation remains controversial. A minimum of 2.0 to 2.5 million CD34⁺ cells/kg of patient weight is requested for a rapid and durable engraftment. The aim of this study was to detect the ratio of CD34+ B-lymphoid progenitors (hematogones) in bone marrow grafts and investigate their effects on hematopoietic recovery after transplant. MATERIALS AND METHODS: Our study included 41 patients who received a bone marrow graft from their HLA-matched donor from 2016 through 2019. The CD34⁺ cell numbers within the graft were detected using Stem-Kit (Beckman Coulter). The ratio of CD34⁺ hematogones was determined either by their light scatter characteristics or by the detection of CD34, CD19, or CD10 coexpressing cells in a separate tube. RESULTS: The median number of CD34⁺ cells was 5.9 × 106/kg (0.8-14.3 × 106/kg). The CD34⁺ cells consisted of 71% (range, 35.7%-100%) and 29% (range, 5.7%-64.3%) myeloid and B-lymphoid progenitors, respectively. Percentage of CD34⁺ (P < .001) and total (P < .001) hematogones in correlation with donor age. Time of neutrophil engraftment was significantly longer (P = .039) when total infused CD34⁺ cell content was <3 × 106/kg. CONCLUSIONS: A remarkable population of hematogones within the CD34⁺ cell pool was detected in bone marrow grafts. Detection of the ratio of hematogones and most primitive stem cells (CD34⁺CD90⁺CD38⁻) may overall provide more information to build a better correlation between CD34⁺ cell content and the recovery of bone marrow.

Significance of inhibitory maternal killer-cell immunoglobulin-like receptor (KIR) and fetal KIR ligand genotype combinations in placenta related obstetric complications.

Some maternal killer-cell immunoglobulin-like receptor (KIR) and fetal KIR ligand genotypes are associated with obstetric complications, such as recurrent miscarriage, fetal growth restriction, preeclampsia, and preterm birth. However, how KIR/KIR ligand genotypes affect these placenta-related obstetric complications has not been fully understood. We aimed to demonstrate the association of maternal KIR-fetal KIR ligand genotype combinations with immunological/metabolic risk factor associated placenta-related obstetric complications. This study consisted of three groups of pregnant women: 1) Miscarriage group (n = 30), 2) Complicated Pregnancy (CP) group (n = 30), and 3) Control group (n = 30). The observed maternal genotype frequencies of all inhibitory and activating KIRs were similar in all groups (p > 0.05). However, inhibitory 2DL3 was quite frequent in the miscarriage group (p = 0.052). There was no difference between groups in terms of centromeric and telomeric maternal haplotypes (p > 0.05). The fetal group 1 HLA-C genotype was frequently detected in the miscarriage and CP groups with rates of 83.3 % and 93.3 % respectively, while the observed frequency was 70 % in the control group. The fetal group 2 HLA-C genotype was the same in all groups. The results demonstrated significantly less fetal group 2 HLA-C homozygosity in the CP groups when compared to the control group (p = 0.020). The fetal HLA-Bw4 genotype was detected more frequently in the miscarriage and CP groups (p = 0.028 and p = 0.001, respectively). The inhibitory KIR/KIR ligand genotype combinations of 2DL3-C1 and 3DL1-Bw4 were more frequent in the miscarriage and CP groups (p = 0.045 and p = 0.002, respectively). Enhanced NK cell inhibition may be one of the mechanisms underlying placenta-related obstetric complications.

A model integrating Killer Immunoglobulin-like Receptor (KIR) haplotypes for risk prediction of COVID-19 clinical disease severity.

Associations between inherited Killer Immunoglobulin-like Receptor (KIR) genotypes and the severity of multiple RNA virus infections have been reported. This prospective study was initiated to investigate if such an association exists for COVID-19. In this cohort study performed at Ankara University, 132 COVID-19 patients (56 asymptomatic, 51 mild-intermediate, and 25 patients with severe disease) were genotyped for KIR and ligands. Ankara University Donor Registry (n:449) KIR data was used for comparison. Clinical parameters (age, gender, comorbidities, blood group antigens, inflammation biomarkers) and KIR genotypes across cohorts of asymptomatic, mild-intermediate, or severe disease were compared to construct a risk prediction model based on multivariate binary logistic regression analysis with backward elimination method. Age, blood group, number of comorbidities, CRP, D-dimer, and telomeric and centromeric KIR genotypes (tAA, tAB1, and cAB1) along with their cognate ligands were found to differ between cohorts. Two prediction models were constructed; both included age, number of comorbidities, and blood group. Inclusion of the KIR genotypes in the second prediction model exp (-3.52 + 1.56 age group - 2.74 blood group (type A vs others) + 1.26 number of comorbidities - 2.46 tAB1 with ligand + 3.17 tAA with ligand) increased the predictive performance with a 92.9% correct classification for asymptomatic and 76% for severe cases (AUC: 0.93; P < 0.0001, 95% CI 0.88, 0.99). This novel risk model, consisting of KIR genotypes with their cognate ligands, and clinical parameters but excluding earlier published inflammation-related biomarkers allow for the prediction of the severity of COVID-19 infection prior to the onset of infection. This study is listed in the National COVID-19 clinical research studies database.

Long-Term Outcomes of Tamoxifen Citrate Therapy and Histo- and Immunopathological Properties in Riedel Thyroiditis.

BACKGROUND: Riedel thyroiditis (RT) is a rare form of thyroiditis; thus, data about the disease course and treatment options are limited. Therefore, we aimed to assess the clinical, serological, radiological, and histopathological features, as well as short- and long-term follow-up of RT patients under glucocorticoid (GC) and tamoxifen citrate (TMX). Parameters related to IgG4-related diseases (IgG4-RD) were also investigated. METHODS: Eight patients with RT diagnosed between 2000 and 2019 were enrolled. Data were collected in a retrospective and prospective manner. The diagnosis was confirmed with histopathological features in all patients. Results of the treatment with GCs on short- to mid-term, followed by TMX in the long term, were evaluated. RESULTS: The mean age at diagnosis was 40.5 ± 6.8 years; female predominance was observed (F/M:7/1). Parameters related to IgG4-RD, like increase in IgG4 serum levels, total plasmablast counts, and IgG4+ plasmablasts, were negative in most of our patients in both active and inactive states of the disease. Likewise, an increased ratio of IgG4/IgG-positive plasma cells >40% could only be observed in 2 cases. GCs followed by TMX were given to the patients with an over-all median follow-up time of 67 (8-216) months. All the patients considerably improved clinically and had a reduction in the size of the mass lesion on GCs, followed by TMX therapy. None of the patients had a recurrence under TMX therapy for a median period of 18.5 (7-96) months. CONCLUSION: Even though RT is suggested to be a member of IgG4-RD, serologic or histological evidence of IgG4 elevation or positivity is only useful for diagnosis and follow-up of RT. The diagnosis should be based on clinical and radiological evidence and confirmed by histopathology. GCs are effective for initial treatment, and TMX is a successful and safe therapeutic option for long-term maintenance therapy.

Single-Center Study of 72 Patients with Severe Combined Immunodeficiency: Clinical and Laboratory Features and Outcomes.

Severe combined immunodeficiency is an inborn error of immunity characterized by impairments in the numbers and functions of T and B lymphocytes due to various genetic causes, and if it remains untreated, patients succumb to infections during the first 2 years of life. PURPOSE AND METHODS: This study reported retrospective data from 72 infants diagnosed with SCID including their major clinical features, HSCT characteristics, and outcomes over a 20-year period (1997-2017). RESULTS: Sixty-one of 72 SCID patients in the study underwent HSCT from 1997 to 2017. Median ages at the time of diagnosis and transplantation were 3.5 months and 5 months, respectively. Consanguinity was present in 68% of the patients, and T - B - NK + phenotype was predominantly identified. The overall survival was 80.3% over a 20-year period. However, the patients transplanted during an active infection had a lower survival rate of 73.9% compared to 100% for patients transplanted infection-free or with a previous infection that had resolved. The survival rate was significantly higher among recipients of HLA-identical transplants (92.9%), compared to recipients of mismatched related transplants (70%). The overall survival increased from 50 (1997-2006) to 85% (2007-2017) during the last 10 years. CONCLUSIONS: This is one of the largest single-center studies in Turkey with extensive experience about SCID patients. Early diagnosis of SCID patients before the onset of an infection and early transplantation are shown to be extremely important factors affecting the outcome and increasing the survival regardless of the donor type based on the results of this study.

Prospective Follow-up of Panel Reactive Antibodies From Diagnosis Until Completion of Therapy Including Allogeneic Stem Cell Transplantation Among Patients With Acute Leukemia.

OBJECTIVES: Existence of panel reactive antibodies is the limiting step in both solid-organ and hematopoietic stem cell transplantation. There are hypotheses related to panel reactive antibody formation, but there is no knowledge about its formation in acute leukemia at diagnosis and during the chemotherapy period, in which there is a strong myelosuppression and immunosuppression. We aimed to determine the panel reactive antibodies positivity in acute leukemia patients at diagnosis and during the entire therapy period, including stem cell transplantation. MATERIALS AND METHODS: In this single-center prospective study, we enrolled 35 patients with acute leukemia (8 with acute lymphoblastic leukemia, 27 with acute myeloid leukemia). Serum samples were obtained before induction therapy and every 3 months thereafter until the last follow-up or death, for a median of 369 days (minimum-maximum, 9-725 days). Panel reactive antibodies were defined with single-antigen bead assays on a Luminex platform. RESULTS: A total of 10 patients (29%) were found to have panel reactive antibodies at any time point. At diagnosis, 5 patients (14.3%) had antibodies of either class I (n = 2) or II (n = 1) or both (n = 2), and in 4 patients these persisted during median follow-up of 168 days (minimum-maximum, 9-322 days). Among the remaining 30 patients, an additional 5 (17%) developed de novo antibodies. Incidence rate of development of de novo antibodies was 5.5 per 10 000 person-days. There was no effect of transfusion load on the development of panel reactive antibodies. Differences in percentages in males versus females, blood type mismatch, and graftversus-host disease were higher in patients who had de novo antibodies after transplantation. Positivity at any time had no statistically significant effect on overall survival (P = .71). CONCLUSIONS: Panel reactive antibodies do not occur frequently in the acute leukemia setting despite intensive transfusions.

Leukemic stem cells shall be searched in the bone marrow before "tyrosine kinase inhibitor-discontinuation" in chronic myeloid leukemia.

BACKGROUND: Leukemic stem cells (LSCs) of chronic myeloid leukemia (CML), persisting in the bone marrow (BM) niche, could be responsible for the relapses within the patients of whom the treatment-free remission (TFR) had been attempted. We assessed the presence of the CML LSCs in the peripheral blood (PB) and concurrently in the BM in the patients with chronic-phase CML (CP CML). PATIENTS AND METHODS: Thirty-eight patients with CP CML were included into the study. CD45+ /CD34+ /CD38- cells with positive CD26 expression were considered as CML LSCs (CD26+ LSC) by using multiparameter flow cytometry (FCM). RESULTS: Mean BCR-ABL, PB LSC, and BM LSC were 58.528 IS (37.405-83.414 IS), 237.5 LSC/µL (16-737.5 LSC/µL), and 805 LSC/106  WBCs (134.6-2470 LSC/106  WBCs), respectively, in newly diagnosed CML patients. In the patients with BCR-ABL positive hematopoiesis, mean BCR-ABL, PB LSCs, and BM LSCs were 30.09 IS (0.024-147.690 IS), 13.5 LSC/µL (0-248.7 LSC/µL) and 143.5 LSC/106  WBCs (9-455.2 LSC/106  WBCs), respectively. No CML LSCs were detected in PB of patients who achieved deep molecular response (DMR). BM LSCs of the patients who were in DMR were 281.1 LSC/106  WBCs (3.1-613.7 LSC/106  WBCs). The amount of PB LSCs was highest in patients with newly diagnosed CML (P < .001). CONCLUSION: LSCs persisted in the BM of the patients with DMR, whereas there was no LSCs in the peripheral blood. The investigation of the CML LSCs in bone marrow before deciding TKI discontinuation could be justified to achieve and maintain stable TFR.

Highlighting the Prognostic Importance of Measurable Residual Disease Among Acute Myeloid Leukemia Risk Factors

Objective: The optimal timing of measurable residual disease (MRD) evaluation in acute myeloid leukemia (AML) patients has not been well defined yet. We aimed to investigate the impact of MRD in pre- and post-allogeneic hematopoietic stem cell transplantation (AHSCT) periods on prognostic parameters. Materials and Methods: Seventy-seven AML patients who underwent AHSCT in complete morphological remission were included. MRD analyses were performed by 10-color MFC and 10-4 was defined as positive. Relapse risk and survival outcomes were assessed based on pre- and post-AHSCT MRD positivity. Results: The median age of the patients was 46 (range: 18-71) years, and 41 (53.2%) were male while 36 (46.8%) were female. The median follow-up after AHSCT was 12.2 months (range: 0.2-73.0). The 2-year overall survival (OS) in the entire cohort was 37.0%, with a significant difference between patients who were MRD-negative and MRD-positive before AHSCT, estimated as 63.0% versus 16.0%, respectively (p=0.005). MRD positivity at +28 days after AHSCT was also associated with significantly inferior 2-year OS when compared to MRD negativity (p=0.03). The risk of relapse at 1 year was 2.4 times higher (95% confidence interval: 1.1-5.6; p=0.04) in the pre-AHSCT MRD-positive group when compared to the MRD-negative group regardless of other transplant-related factors, including pre-AHSCT disease status (i.e., complete remission 1 and 2). Event-free survival (EFS) was significantly shorter in patients who were pre-AHSCT MRD-positive (p=0.016). Post-AHSCT MRD positivity was also related to an increased relapse risk. OS and EFS were significantly inferior among MRD-positive patients at +28 days after AHSCT (p=0.03 and p=0.019). Conclusion: Our results indicate the importance of MRD before and after AHSCT independently of other factors.

A CD34+ Cell Enrichment Protocol of Hematopoietic Stem Cells in a Well-Established Quality Management System.

Allogeneic stem cell transplantation applications have improved tremendously over the past quarter of a century. The use of new immunosuppressive protocols and elimination of T cells by CD34+ cell enrichment or T cell depletion on apheresis products increases the chance of using partially matched or haploidentical grafts. This is without increasing the risk of graft-versus-host disease, which is observed as a major complication of hematopoietic stem cell transplantation. The aim of this protocol is to evaluate the results obtained from 6 different process cycles performed on 6 different days. We used the CliniMACS Plus system located in our Cell and Tissue Manufacturing Center Quality Control Unit which is already calibrated as a class D room and includes a class A microbiological safety cabinet inside. The average purity of the end products was 95.66%, excluding only one end product which was 70%; this was higher than the values in current studies in the field. Superior to the reported studies, the CD3 quantity in each end product was below the dedicated thresholds. BactecTM FX40 blood culture system test results were detected as negative for each end product. Endotoxin testing suggested the absence of endotoxin within the products. The consistent outcomes obtained from these 6 different process cycles confirmed that the CliniMACS® Plus process cycles performed in accordance with our well-defined quality management system procedure is sufficient for the routine application of high-quality and safe CD34+ enrichment processes within our clean room area.

Comparison of the methods evaluating post thawing viability of peripheral blood stem cell graft.

OBJECTIVE: Reliable and pratique methods are essential for rapid and accurate determination of post thawing viability of peripheral blood stem cell (PBSC) graft before hematopoietic stem cell transplantation. In this study, Trypan Blue (TP) Eosin Y (EO), and Acridine-orange-ethidium bromide (AO/EB), which are of the methods commonly used for the assessment of viability in clinic practice, were compared with the flow cytometry-7AAD (7AAD) method, which is a more sensitive method. The aim of this study is to examine which method evaluates postthawing viability in a more compatible manner with 7AAD. MATERIALS-METHODS: Postthawing viability rates were examined simultaneously by means of four different methods before hematopoietic stem cell transplantation in a total of 20 PBSC graft. The results obtained from the AO/EB, TP, EO methods were evaluated with the flow cytometry-7AAD in terms of concordance. RESULTS: The AO / EB was determined to be the method having the best concordance with the flow cytometry-7AAD method. Although, at a lower level compared to the AO/EB method, the EO method had a statistically significant concordance with the flow cytometry-7AAD method. No statistically significant concordance was detected between the TP method and 7AAD method in terms of viability results. CONCLUSION: The AO/EB method was identified to be the method having the best compatibility with the flow cytometry -7AAD method in showing the viability of the cryopreserved PBSC graft. In the viability assessment of PBCS graft using light microscopy, the EO may be preferred since is more sensitive compared to the TP method.

Donor-recipient killer immunoglobulin like receptor (KIR) genotype matching has a protective effect on chronic graft versus host disease and relapse incidence following HLA-identical sibling hematopoietic stem cell transplantation.

Impact of donor-recipient killer immunoglobulin-like receptor (KIR) gene-gene matching on transplant outcomes is still inconclusive. Recent data suggest that killer cell immunoglobulin-like receptor (KIR) regulated natural killer cell (NK cell) activity may contribute to graft versus leukemia (GvL) effects and graft versus host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This case-control study aims to evaluate the effects of both aKIR and iKIR donor-recipient genotype matching on the outcomes of T cell replete HLA-identical sibling allo-HSCTs in a homogenous young patient population with myeloid leukemias. Five transplant outcomes including relapse rate (RR), disease-free survival (DFS), overall survival (OS), cumulative incidences of acute GvHD (aGvHD), and chronic GvHD (cGvHD) are investigated. Out of 96 HLA-identical sibling donor-recipient pairs, 34 were matched for activating KIR (aKIR), 38 for inhibitory KIR (iKIR), and 20 for both aKIR and iKIR. Fourty-four pairs were mismatched for both iKIR and aKIR. In univariate analysis, aKIR-matching resulted with a decrease in relapse rate (RR) (hazard ratio [HR]: 0.4; p = 0.04) and an increase in disease-free survival (DFS) (HR: 0.5; p = 0.03). In addition, cGvHD ocurred less frequently in the aKIR-matched (odds ratio [OR]: 0.4; p = 0.04) or iKIR-matched (OR: 0.3; p = 0.009) cohorts. Matching for both aKIR and iKIR was also associated with a decrease in cGvHD incidence (OR: 0.3; p = 0.02). iKIR-matching had no effects on RR, OS, or DFS. Analysis of donor haplotype effects showed haplotype-BB to have a tendency towards reduced relapse rate (HR: 0.4; p = 0.08) and better OS (HR: 0.4; p = 0.04); haplotype-Bx to increase the incidence of cGvHD (OR: 4.1; p = 0.03). In multivariate analysis, DFS advantage remained significant for aKIR-matching (HR: 0.5; p = 0.04); cGvHD incidence was reduced in the presence of iKIR-match (OR: 0.3; p = 0.02) and increased in the presence of haplotype-AB and -BB donors (OR: 7.9; p = 0.02; OR: 5.1; p = 0.03, respectively). In an attempt to investigate the pathogenesis underlying KIR-matching, we searched for residual NK/T cells on day 0 peripheral blood samples of six additional recipients and noted the presence of CD3+ (7.0-91.4 × 106/L) and CD56+57+ (0.8-12.7 × 106/L) cells. In conclusion, conditioning regimen surviving recipient NK/T cells potentially influenced by KIR-matching may contribute to GvL/GvH reactions.

Differential gene expression profiling of human adipose stem cells differentiating into smooth muscle-like cells by TGFß1/BMP4.

Regenerative repair of the vascular system is challenging from the perspectives of translational medicine and tissue engineering. There are fundamental hurdles in front of creating bioartificial arteries, which involve recaputilation of the three-layered structure under laboratory settings. Obtaining and maintaining smooth muscle characteristics is an important limitation, as the transdifferentiated cells fail to display mature phenotype. This study aims to shed light on the smooth muscle differentiation of human adipose stem cells (hASCs). To this end, we first acquired hASCs from lipoaspirate samples. Upon characterization, the cells were induced to differentiate into smooth muscle (SM)-like cells using a variety of inducer combinations. Among all, TGFß1/BMP4 combination had the highest differentiation efficiency, based on immunohistochemical analyses. hSM-like cell samples were compared to hASCs and to the positive control, human coronary artery-smooth muscle cells (hCA-SMCs) through gene transcription profiling. Microarray findings revealed the activation of gene groups that function in smooth muscle differentiation, signaling pathways, extracellular modeling and cell proliferation. Our results underline the effectiveness of the growth factors and suggest some potential variables for detecting the SM-like cell characteristics. Evidence in transcriptome level was used to evaluate the TGFß1/BMP4 combination as a previously unexplored effector for the smooth muscle differentiation of adipose stem cells.

The effect of age on peripheral stem cell mobilization in healthy donors, single center experience.

PURPOSE: Peripheral stem cell transplantation is used as a life-saving therapeutic option in hematological malignancies. As previously established, most hematological malignancies are seen in the elderly population. Therefore, possible HLA-identical sibling donors of elderly patients are generally of an advanced age. In this study, we aimed to evaluate the effect of old age on stem cell mobilization and quality in older adult healthy sibling donors. MATERIALS AND METHODS: Between 2006 and 2014, we evaluated 38 healthy donors aged ≥55 years. The granulocyte-colony stimulating factor (G-CSF) analogs were used at a dose of 5 µg/kg/day and administered subcutaneously twice a day for five days. CD34+ cells were estimated in the peripheral blood before collection of the apheresis product. The National Marrow Donor Program selects healthy unrelated donors if they are younger than 60 years. Therefore, we compared the product quality in donors over the age of 60 to that in donors aged 60 years or less. RESULTS: We collected sufficient products from all the donors with one to three apheresis procedures. No serious complication was detected in all donors. Reaching the target CD34+ cell count in one day were detected in 83% of younger and 79% of older donors (P = NS). Collected CD34+ cells x10e6/recipient body weight (kg) was same and 5.1 in the groups (P = NS). There were no correlation between the donor age and these parameters. CONCLUSION: Healthy donor apheresis in older adults can be performed effectively and possible donors should be evaluated regardless of their age. J. Clin. Apheresis 32:16-20, 2017. © 2016 Wiley Periodicals, Inc.