Hai-xia Fu

Prolonged Thrombocytopenia Following Allogeneic Hematopoietic Stem Cell Transplantation and Its Association with a Reduction in Ploidy and an Immaturation of Megakaryocytes

Prolonged thrombocytopenia is a frequent complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT); however, its pathogenesis has remained obscure. In the present study, we used flow cytometry to determine the frequency of bone marrow megakaryocytes (MKs) and MK ploidy distributions in allo-HSCT recipients with or without prolonged thrombocytopenia (n = 32 and 27, respectively) and healthy volunteers (n = 13). In addition, the expression of c-Mpl in MKs was measured. The results indicate that the proportions of MKs in marrow mononuclear cells or the percentages of CD110(+) MKs in total MKs did not significantly differ between the 3 groups; however, in a comparison of nonthrombocytopenic allo-HSCT recipients to healthy volunteers, the allo-HSCT patients who had prolonged thrombocytopenia exhibited significant shifts toward low ploidy cells (left shift), which were accompanied by a marked increase in ≤ 8N cells (P = .036 and P < .001, respectively) and significant decreases in 16N cells (P < .001 and P < .001, respectively) and ≥ 32N cells (P = .01 and P <.001, respectively). These results indicate that there were more immature MKs in allo-HSCT recipients who had prolonged thrombocytopenia, in comparison to nonthrombocytopenic allo-HSCT recipients and healthy volunteers. We conclude that prolonged thrombocytopenia and slow platelet engraftment after allo-HSCT may be related to a reduction in ploidy and an immaturation of MKs.

Cytomegalovirus is a potential risk factor for late‐onset hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation

Late‐onset hemorrhagic cystitis (LOHC) is a common complication following allogeneic hematopoietic stem cell transplantation (allo‐HSCT) and is primarily associated with viral infection. We prospectively quantified cytomegalovirus (CMV), BK virus (BKV), and adenovirus in urine and plasma using Q‐RT‐PCR in 50 consecutive patients to define the relationship between virus and LOHC. Of the 50 patients, 21 developed LOHC at a median of 29 days (range 4–64 days), with a cumulative incidence of 42% (±7.1%). The cumulative incidence of LOHC on day 100 in patients with and without CMV viremia (prior to or at the onset of LOHC) were 56.3% (±8.9%) and 16.7% (±9.1%) (P = 0.018), respectively, and it was 59.3% (±9.8%) and 21.7% (±8.8%) in patients with and without CMV viruria (prior to or at the onset of LOHC) (P = 0.021), respectively. The cumulative incidence of LOHC was also higher in patients with a plasma BKV load increased ≥3 log10 or with a urine BKV load increased ≥4 log10 than those without the increase (P < 0.001). Only one patient with LOHC was tested positive for ADV. Both the univariate and multivariate analyses showed that CMV viremia (HR = 3.461, 95% CI: 1.005–11.922, P = 0.049) and a plasma BKV load that was increased ≥3 log10 (HR = 10.705, 95%CI: 2.469–46.420, P = 0.002) were independent risk factors for the development of LOHC. We conclude that both CMV viremia and an increase of plasma BKV are independent risk factors for LOHC. And the role of CMV viremia was firstly demonstrated. Am. J. Hematol. 89:55–61, 2014.

Epileptic seizures in patients following allogeneic hematopoietic stem cell transplantation: a retrospective analysis of incidence, risk factors, and survival rates.

The incidence of epileptic seizures among allogeneic hematopoietic stem cell transplant (allo‐HSCT) patients has been poorly described. No report has systematically studied epilepsys possible causes, risk factors, and effect on prognosis among allo‐HSCT patients. We retrospectively examined data from 1461 patients who underwent allo‐HSCT within the past 6.5 yr at the Institute of Hematology and Peoples Hospital, Peking University. The cumulative incidence of all epileptic seizure complications was 7.1%. Of the 79 transplant patients who had epileptic seizures, 3 (3.8%) experienced a seizure during the conditioning stage, 52 (65.8%) between day 0 and day 100, 20 (25.3%) from day 100 to the first year, and 4 (5.1%) after the first year. Multivariate regression analysis identified the age of the recipient as (≤18 yr) (p < 0.001), donor type (p = 0.004), graft versus host disease (aGVHD) (p = 0.018), and hyponatremia (p = 0.003) as independent risk factors for epileptic seizures among allo‐HSCT patients. The median survival time of patients with epileptic seizures was 246 d after transplantation (ranging between 18 and 2170 d). Survival after one yr and 6.5 yr was significantly reduced in patients who developed epileptic seizure complications compared with those who did not (57.2% vs. 75.7% at one yr, p = 0.015, and 31.1% vs. 71.4% at five yr, p < 0.001). Of the 79 patients who experienced epileptic seizure complications, 53.2% died (n = 42). The survival rate of these patients was relatively low, and cerebrovascular disorders or central nervous system infection‐related epileptic seizures usually resulted in a high mortality and poor prognosis. A patient transplantation age which is younger than 18 yr, related mismatched transplants, aGVHD, and hyponatremia are risk factors for epileptic seizures in allo‐HSCT recipients. Epileptic seizures among allo‐HSCT patients are associated with a poor prognosis.

Platelet-Derived Growth Factor-BB Protects Mesenchymal Stem Cells (MSCs) Derived From Immune Thrombocytopenia Patients Against Apoptosis and Senescence and Maintains MSC-Mediated Immunosuppression

Immune thrombocytopenia (ITP) is characterized by platelet destruction and megakaryocyte dysfunction. Mesenchymal stem cells (MSCs) from ITP patients (MSC‐ITP) do not exhibit conventional proliferative abilities and thus exhibit defects in immunoregulation, suggesting that MSC impairment might be a mechanism involved in ITP. Platelet‐derived growth factor (PDGF) improves growth and survival in various cell types. Moreover, PDGF promotes MSC proliferation. The aim of the present study was to analyze the effects of PDGF‐BB on MSC‐ITP. We showed that MSC‐ITP expanded more slowly and appeared flattened and larger. MSC‐ITP exhibited increased apoptosis and senescence compared with controls. Both the intrinsic and extrinsic pathways account for the enhanced apoptosis. P53 and p21 expression were upregulated in MSC‐ITP, but inhibition of p53 with pifithrin‐α markedly inhibited apoptosis and senescence. Furthermore, MSCs from ITP patients showed a lower capacity for inhibiting the proliferation of activated T cells inducing regulatory T cells (Tregs) and suppressing the synthesis of anti‐glycoprotein (GP)IIb‐IIIa antibodies. PDGF‐BB treatment significantly decreased the expression of p53 and p21 and increased survivin expression in MSC‐ITP. In addition, the apoptotic rate and number of senescent cells in ITP MSCs were reduced. Their impaired ability for inhibiting activated T cells, inducing Tregs, and suppressing the synthesis of anti‐GPIIb‐IIIa antibodies was restored after PDGF‐BB treatment. In conclusion, we have demonstrated that PDGF‐BB protects MSCs derived from ITP patients against apoptosis, senescence, and immunomodulatory defects. This protective effect of PDGF‐BB is likely mediated via the p53/p21 pathway, thus potentially providing a new therapeutic approach for ITP.

Thrombotic microangiopathy with concomitant GI aGVHD after allogeneic hematopoietic stem cell transplantation: Risk factors and outcome

To explore the possible risk factors for the occurrence and mortality of thrombotic microangiopathy (TMA) with concomitant acute graft‐vs‐host disease (aGVHD) and to investigate outcomes and treatments of this disorder after allo‐HSCT.

Helicobacter pylori infection influences the severity of thrombocytopenia and its treatment response in chronic hepatitis B patients with compensatory cirrhosis: A multicenter, observational study

Abstract The role of Helicobacter pylori (H. pylori) infection on thrombocytopenia in chronic hepatitis B (CHB) related compensatory cirrhotic patients is unknown. We conducted an observational study to determine whether H. pylori plays a role in these patients. A total of 255 patients from three centers in China were enrolled in the study. All patients received nucleoside analogs (NA) therapy and were screened for H. pylori infection. Patients were divided into three groups based on their H. pylori infection status and the therapy administered: patients without H. pylori infection who received NA therapy alone (N = 146); patients with H. pylori infection who received NA therapy alone (n = 48); and patients with H. pylori infection who received H. pylori eradication combined with NA therapy (N = 61). We observed that in CHB compensatory cirrhotic patients with H. pylori infection, the platelets count was significantly lower relative to uninfected patients (31 versus 60 × 109/L, p < 0.01). During a 2-year follow-up, the elevation in platelet count was significantly higher in HBV/H. pylori co-infected patients who received the NA and H. pylori eradication treatment compared to the other two groups (p < 0.01). It suggested that H. pylori infection and eradication treatment combined with NA were independent risk factors associated with platelets response during treatment of thrombocytopenia in CHB compensatory cirrhosis (p < 0.01). In conclusion, H. pylori infection may associate with thrombocytopenia in CHB compensatory cirrhosis. H. pylori eradication combined with NA treatment may prove to be beneficial to CHB compensatory cirrhotic patients with thrombocytopenia who are infected with H. pylori.

Characterization of thrombopoietin kinetics within 60 days after allogeneic hematopoietic stem cell transplantation and its correlation with megakaryocyte ploidy distribution

Thrombopoietin (TPO) has been identified as a key cytokine for both megakaryogenesis and thrombopoiesis. We attempt to characterize the kinetics of TPO and its correlation with megakaryocytes (MKs) ploidy distribution pattern within 60 d after allogeneic hematopoietic stem cell transplantation (allo‐HSCT). Forty‐six consecutive patients undergoing allo‐HSCT from October 2008 to December 2008 were included. TPO levels and ploidy distribution patterns of MKs were measured using ELISA and flow cytometric analysis, respectively. The results indicated that TPO levels and the platelet count followed opposite trends after allo‐HSCT. The preconditioning TPO levels and the number of transplanted CD34+ cells were significant predisposing factors for rapid platelet engraftment (p = 0.010 and 0.007, respectively) by multivariate analysis. There was a reduction of ploidy and an increase in immature MKs in patients with higher endogenous TPO levels (>250 pg/mL) on day 60 after allo‐HSCT. Moreover, lower TPO levels (≤250 pg/mL) on day 60 after allo‐HSCT were associated with significantly improved five‐yr overall survival (p = 0.021) and reduced transplant‐related mortality (p = 0.033). In conclusion, endogenous TPO levels may be associated with platelet recovery and have prognostic significance during allo‐HSCT.

Adipose-Derived Mesenchymal Stem Cells (ADSCs) with the Potential to Ameliorate Platelet Recovery, Enhance Megakaryopoiesis, and Inhibit Apoptosis of Bone Marrow Cells in a Mouse Model of Radiation-Induced Thrombocytopenia:

Substantial damage to the bone marrow can be caused by exposure to radiation, which can then develop into severe thrombocytopenia. In this study, we investigated the in vivo impact of adipose-derived mesenchymal stem cells (ADSCs) on megakaryopoiesis and platelet recovery in irradiated mice. Radiation markedly reduced peripheral blood counts. Recovery of both platelets and WBCs was better in the ADSC-treated group compared with the saline group and the fibroblast group 21 days after irradiation. A significant increase in the total CFU and MK-CFU after irradiation was observed in the ADSC group compared with the saline group and the fibroblast group. Further, the proportion of CD41+ cells in the ADSC group was significantly higher than that in the saline group and the fibroblast group. ADSC treatment significantly improved the cellularity and decreased the apoptotic cells in the bone marrow while normal fibroblasts did not. Administration of ADSCs upregulated protein expression of phosphorylated Akt and Bcl-xL, whereas the expression of Bax, a protein related to apoptosis, was significantly lower in the ADSC group. In conclusion, this study suggests that ADSCs were capable of promoting platelet recovery, improving megakaryopoiesis, and inhibiting apoptosis of bone marrow cells in irradiated mice. The antiapoptotic effect of ADSCs is likely to be mediated via the PI3K/Akt pathway. These findings may provide a scientific basis for using ADSCs as a new therapy after irradiation.

Combination of FVIII and low-dose rFVIIa improves haemostasis in acquired haemophilia A patients: a collaborative controlled study

INTRODUCTION Acquired haemophilia A (AHA) is an autoimmune disease that potentially leads to severe bleeding and has a high rate of mortality. This collaborative study aimed to assess the efficacy of the co-administration of FVIII and low-dose rFVIIa in patients with AHA. MATERIALS AND METHODS This study retrospectively compared the combined FVIII/low-dose rFVIIa therapy (initial dose range of 25-55μg/Kg) with the combined FVIII/PCC therapy and low-dose rFVIIa monotherapy. Adverse drug reactions and recurrent bleeding episodes were also monitored. Crude comparisons and the exact conditional logistic regression were performed to compare the outcomes between three treatment groups. RESULTS First bleeding episodes of 56 consecutive patients from 5 centres were analyzed, and 37 bleeding episodes (66.1%) were determined to be severe. Specifically, the rate of bleeding control was significantly higher with the FVIII/low-dose rFVIIa therapy compared to that of the low-dose rFVIIa alone therapy or the FVIII/PCC therapy (58.3% vs. 41.7% vs. 95.0%, respectively). Analyzing of total 236 bleeding episodes showed a clear positive association between the early initiation of haemostatic treatment and efficacy. No therapy-related adverse events in which thrombosis predominated were reported. CONCLUSIONS The combination of FVIII and low-dose rFVIIa offers an ideal haemostatic cover and may be promoted as a feasible and safe therapy protocol for patients with AHA.

Mesenchymal stem cell deficiency influences megakaryocytopoiesis through the TNFAIP3/NF-κB/SMAD pathway in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disease. Mesenchymal stem cells (MSCs) play important roles in the physiology and homeostasis of the haematopoietic system, including supporting megakaryocytic differentiation from CD34+ haematopoietic progenitor cells. Tumour necrosis factor alpha‐induced protein 3 (TNFAIP3, also termed A20) plays a key role in terminating NF‐κB signalling. Human genetic studies showed that the polymorphisms of the TNFAIP3 gene may contribute to ITP susceptibility. In this study, we showed a significant decrease in TNFAIP3 and increase in NF‐κB/SMAD7 in ITP‐MSCs. In co‐cultures with CD34+ cells, NF‐κB was overexpressed in MSCs from healthy controls (HC‐MSCs) after transfection with NFKBIA (IκB)‐specific short hairpin (sh)RNAs, resulting in MSC deficiency and a reduction in megakaryocytic differentiation and thrombopoiesis. Knockdown of TNFAIP3 expression using TNFAIP3‐specific shRNAs in HC‐MSCs affected megakaryocytopoiesis. However, IKBKB knockdown corrected megakaryocytopoiesis inhibition in the ITP‐MSCs by decreasing NF‐κB expression. Amplified TNFAIP3 expression in ITP‐MSCs by TNFAIP3 cDNA can facilitate megakaryocyte differentiation. shRNA‐mediated knockdown of SMAD7 expression rescued the impaired MSC function in ITP patients. Therefore, we demonstrate that a pathological reduction in TNFAIP3 levels induced NF‐κB/SMAD7 pathway activation, causing a deficiency in MSCs in ITP patients. The ability of ITP‐MSCs to support megakaryocytic differentiation and thrombopoiesis of CD34+ cells was impaired.