A novel germline HAVCR2 (TIM-3) compound heterozygous mutation is related to hemophagocytic lymphohistiocytic syndrome in EBV-positive peripheral T-cell lymphoma (NOS) with down-regulated TIM-3 signaling.

Recently, it have been reported that Hepatitis A Virus-Cellular Receptor 2(HAVCR2,encoding T-cell immunoglobulin and Mucin-Containing Protein 3[TIM3]) mutations are associated with severe hemophagocytic syndrome(HLH) in subcutaneous panniculitis-like T-cell lymphoma(SPTCL),and there are also frequent mutations in sporadic SPTCL, suggesting the individuals harboring HAVCR2(TIM-3) germline mutations are highly susceptible to familial or sporadic SPTCL. Here, we identify a novel germline compound heterozygous mutation of TIM-3 gene,c.245A>G (p.Tyr82Cys) and c.265C>T(p.Arg89Cys) variations in a single familial case with EBV-positive peripheral T-cell lymphoma(NOS),accompanied HLH;we also detected Tyr82Cys germline mutation in TIM-3 gene in one sporadic patient with cutaneous T cell lymphoma. We screened the distributive frequencies for TIM-3 mutations in healthy controls(n=87), B-(n=79) or T-cell lymphoma(n=25) not SPTCL, and the results showed that the mutation was found in two out of 25 patients with T-cell lymphoma but was not detected in 79 patients with B-cell lymphoma nor in a group of 87 controls. The mRNA expression of TIM-3 on primary cells and transfected HEK293 cells reduced significantly, indicating Tyr82Cys and Arg89Cys mutations is a loss-of function mutations on TIM-3,resulting in a weakened TIM-3 signaling. Our results suggest Tyr82Cys TIM-3 germline mutations are not only limited in SPTCL, and also occurred in other types of T-cell lymphoma, especially complicated HLH. TIM-3 mutations may be an predisposing factor for T-cell lymphoma and molecular marker for auxiliary diagnosis in T cell lymphoma,especially complicated with HLH.

CHST15 gene germline mutation is associated with the development of familial myeloproliferative neoplasms and higher transformation risk.

Herein, we describe the clinical and hematological features of three genetically related families predisposed to myeloproliferative neoplasms (MPNs). Using whole-exome sequencing, we identified a c.1367delG mutation(p.Arg456fs) in CHST15 (NM_001270764), a gene encoding a type II transmembraneglycoproteinthat acts as a sulfotransferase and participates in the biosynthesis of chondroitin sulfate E, in germline and somatic cells in familial MPN. CHST15defects caused an increased JAK2V617F allele burden and upregulated p-Stat3 activity,leading to an increase in the proliferative and prodifferentiation potential of transgenic HEL cells. We demonstrated that mutant CHST15 is able to coimmmunoprecipitate the JAK2 protein,suggesting the presence of a CHST15-JAK2-Stat3 signaling axis in familial MPN. Gene expression profiling showed that the FREM1, IFI27 and C4B_2 genes are overexpressed in familial MPN, suggesting the activation of an "inflammatory response-extracellular matrix-immune regulation" signaling network in the CHST15 mutation background.We thus concluded that CHST15 is a novel gene that predisposes to familial MPN and increases the probability of disease development or transformation.

LncRNA-NEAT1 promotes proliferation of T-ALL cells via miR-146b-5p/NOTCH1 signaling pathway.

BACKGROUND: T-cell acute lymphoblastic leukemia (T-ALL) is a malignant tumor of the hematopoietic system, which can develop at any age, with the symptoms of weakness, fatigue, enlarged lymph nodes, or weight loss. Nuclear paraspeckle assembly transcript 1 (NEAT1) is involved in the process of T-ALL, but the regulatory mechanism is still not known clearly. METHODS: The expression levels of NEAT1 and miR-146b-5p in T-ALL cells were performed by qRT-PCR and NOTCH1 protein level- wwWwas determined by western blot assay. Dual-luciferase reporter assay was used to detect the interaction between NEAT1 and miR-146b-5p, as well as miR-146b-5p and NOTCH1. The cell proliferation was measured by using MTT assay and colony formation assay. RESULTS: The expression levels of NEAT1 were markedly increased, but miR-146b-5p levels were reduced in T-ALL cells. Knockdown of NEAT1 or overexpression of miR-146b-5p decreased NOTCH1 expression, inhibited the proliferation of T-ALL cells. MiR-146b-5p bound both NEAT1 and NOTCH1 3'-UTR directly. Finally, inhibition of miR-146b-5p could abrogate the effects of NEAT1 knockdown on the proliferation of T-ALL cells. CONCLUSION: NEAT1 promotes the proliferation of T-ALL cells by sponging miR-146b-5p to upregulate the expression of NOTCH1. The results of this study provide new insight into the action mechanism of NEAT1 modulating T-ALL progression.

A small molecular compound CC1007 induces cross-lineage differentiation by inhibiting HDAC7 expression and HDAC7/MEF2C interaction in BCR-ABL1- pre-B-ALL.

Histone deacetylase 7 (HDAC7), a member of class IIa HDACs, has been described to be an important regulator for B cell development and has a potential role in B cell acute lymphoblastic leukemia (B-ALL). CC1007, a BML-210 analog, is designed to indirectly inhibit class IIa HDACs by binding to myocyte enhancer factor-2 (MEF2) and blocking the recruitment of class IIa HDACs to MEF2-targeted genes to enhance the expression of these targets. In this study, we investigated the anticancer effects of CC1007 in breakpoint cluster region-Abelson 1 fusion gene-negative (BCR-ABL1-) pre-B-ALL cell lines and primary patient-derived BCR-ABL1- pre-B-ALL cells. CC1007 had obvious antileukemic activity toward pre-B-ALL cells in vitro and in vivo; it also significantly prolonged median survival time of pre-B-ALL-bearing mice. Interestingly, low dose of CC1007 could inhibit proliferation of BCR-ABL1- pre-B-ALL cells in a time-dependent manner not accompanied by significant cell apoptosis, but along with cross-lineage differentiation toward monocytic lineage. From a mechanistic angle, we showed that HDAC7 was overexpressed in BCR-ABL1- pre-B-ALL cells compared to normal bone marrow samples, and CC1007 could reduce the binding of HDAC7 at the promoters of monocyte-macrophage-specific genes via inhibition of HDAC7 expression and HDAC7:MEF2C interaction. These data indicated that CC1007 may be a promising agent for the treatment of BCR-ABL1- pre-B-ALL.

A novel NAP1L4/NUTM1 fusion arising from translocation t(11;15)(p15;q12) in a myeloid neoplasm with eosinophilia and rearrangement of PDGFRA highlights an unusual clinical feature and therapeutic reaction.

NUT midline carcinoma (NMC) is an aggressive neoplasm and mainly involved in the head and neck area. The defining genetic hallmark on these tumors is that testis-specific nuclear gene (NUTM1) fuses to bromodomain protein family member 4 gene (BRD4), resulting in the formation of BRD4-NUTM1 transcript. Here, we report a case with myeloid neoplasm complicating with eosinophilia (MLN-Eo) and rearrangement of PDGFRA, which co-exists with a new nucleosome assemble protein 1-like 4 gene (NAP1L4) NAP1L4-NUTM1 fusion. The patient have unusually clinical features and therapeutic reaction to imatinib mesylate. The cloned NAP1L4-NUTM1 gene structure is also determined.

Analyses of virus/viroid communities in nectarine trees by next-generation sequencing and insight into viral synergisms implication in host disease symptoms.

We analyzed virus and viroid communities in five individual trees of two nectarine cultivars with different disease phenotypes using next-generation sequencing technology. Different viral communities were found in different cultivars and individual trees. A total of eight viruses and one viroid in five families were identified in a single tree. To our knowledge, this is the first report showing that the most-frequently identified viral and viroid species co-infect a single individual peach tree, and is also the first report of peach virus D infecting Prunus in China. Combining analyses of genetic variation and sRNA data for co-infecting viruses/viroid in individual trees revealed for the first time that viral synergisms involving a few virus genera in the Betaflexiviridae, Closteroviridae, and Luteoviridae families play a role in determining disease symptoms. Evolutionary analysis of one of the most dominant peach pathogens, peach latent mosaic viroid (PLMVd), shows that the PLMVd sequences recovered from symptomatic and asymptomatic nectarine leaves did not all cluster together, and intra-isolate divergent sequence variants co-infected individual trees. Our study provides insight into the role that mixed viral/viroid communities infecting nectarine play in host symptom development, and will be important in further studies of epidemiological features of host-pathogen interactions.

[Prognostic Value of Corrected Levels of Serum Calcium and Serum Lactate Dehydrogenase for Newly Diagnosed Multiple Myeloma Patients].

OBJECTIVE: To investigate the prognostic value of the serum calcium level corrected by serum albumin (cCA) and corrected serum lactate dehydrogenase (LDH) level for the risk stratification for newly diagnosed multiple myeloma (MM) patients. METHODS: The clinical data and survival of 186 newly diagnosed MM patients admitted to our hospital from June 1, 2015 to November 1, 2017 were collected. The patients's survival time was obtained by telephone and follow-up visits to patients and their families. The value of the prognostic system consisting of cCA levels and LDH levels in the survival time of MM patients was retrospectively analyzed. Moreover, the post-corrected hypercalcemia and high LDH as 2 factors were used for risk stratification, then according to these 2 factors, the MM patients were divided into 3 groups: group 1 (no risk factor), group 2 (1 risk factor) and group 3 (2 risk factors), and the effect of risk factors on the prognosis of MM patients was analyzed. RESULTS: The median follow-up time was 16 months. The cumulative OS rate of the post-corrected hypercalcemia group was lower than that of the non-hypercalcemia group. The 1-year cumulative OS rate in the 2 groups was 79.0%±6.7% and 88.6%±3.0%, the 3-year cumulative OS rate was 53.0%±10.5% and 74.6%±6.6% (P=0.016), respectively. The cumulative OS rate of the high LDH group [LDH ＞upper limit of normal (ULN), ULN=250 U/L] was lower than that in the normal LDH group. The 1-year cumulative OS rate in the 2 groups was 71.6%±8.6% and 90.0%±2.8%, the 2-year cumulative OS rate was 44.9%±12.1% and 83.1%±4.0%, respectively, and the median OS time was 19 months (95%CI: 15.32-23.34) and not reached (P=0.001). The risk stratification analysis showed that the median OS time of the 3 group was not reached (n=103, 57%), not reached (n=70, 39%) and 17 months (n=7, 4%, 95%CI: 5.19-28.41, P＜0.001). Patients with two risk factors had a prognosis worse than patients with 0-1 risk factor. CONCLUSION: The prognostic combination of corrected serum calcium and LDH levels may provide a basis for risk stratification and prognosis in MM patients in clinical practice.

RNF8 is responsible for ATRA resistance in variant acute promyelocytic leukemia with GTF2I/RARA fusion, and inhibition of the ubiquitin-proteasome pathway contributes to the reversion of ATRA resistance.

BACKGROUND: GTF2I-RARA is a newly identified RARA fusion gene in variant acute promyelocytic leukemia (APL) patients with t(7;17)(q11;q21). Clinical manifestation in the patient showed that it is a sort of ATRA-insensitive oncogene and is different from the classic PML-RARA in terms of therapeutic reaction. METHODS: To reveal the functional characteristics and regulating mechanism of the GTF2I-RARA fusion gene, we established a GTF2I-RARA-transfected HL60 cell model and examined its sensitivity to ATRA by western blot, MTT assay, flow cytometry, and Wright-Giemsa staining. Coimmunoprecipitation and confocal microscopy were used to examine the binding of GTF2I-RARA and transcriptional corepressors. We also performed ChIP-seq to search for potential target genes. Immunoprecipitation, ubiquitination assay, western blot, luciferase assay, and real-time PCR were used to analyze the effects of RNF8 on RARA. Flow cytometry and Wright-Giemsa staining were used to study the effect of MG132 and ATRA on the GTF2I-RARA-transfected HL60 cell model. RESULT: We confirmed resistance of GTF2I-RARA to ATRA. Compared with PML-RARA, GTF2I-RARA has a higher affinity to HDAC3 under ATRA treatment. Using the ChIP-sequencing approach, we identified 221 GTF2I-RARA binding sites in model cells and found that the RING finger protein 8 (RNF8) is a target gene of GTF2I-RARA. RNF8 participates in disease progression and therapy resistance in APL with the GTF2I-RARA transcript. Elevated RNF8 expression promotes the interaction between RARA and RNF8 and induces RARA Lys-48 linkage ubiquitylation and degradation, resulting in attenuated transcriptional activation of RARA. CONCLUSION: Our results suggest that RNF8 is a key GTF2I-RARA downstream event. Using the combination of MG132 and ATRA to treat GTF2I-RARA-HL60 cells, a synergistic effect leading to GTF2I-RARA-HL60 cell differentiation was confirmed. Taken together, the targeting of RNF8 may be an alternative choice for treatment in variant APL with GTF2I-RARA fusion.

(-)-Epigallocatechin-3-gallate induces cell apoptosis in chronic myeloid leukaemia by regulating Bcr/Abl-mediated p38-MAPK/JNK and JAK2/STAT3/AKT signalling pathways.

Epigallocatechin-3-gallate (EGCG), a major polyphenolic constituent of green tea, possesses remarkable chemopreventive and therapeutic potential against various types of cancer, including leukaemia. However, the molecular mechanism involved in chronic myeloid leukaemia (CML), especially imatinib-resistant CML cells, is not completely understood. In the present study, we investigated the effect of EGCG on the growth of Bcr/Abl+ CML cell lines, including imatinib-resistant cell lines and primary CML cells. The results revealed that EGCG could inhibit cell growth and induce apoptosis in CML cells. The mechanisms involved inhibition of the Bcr/Abl oncoprotein and regulation of its downstream p38-MAPK/JNK and JAK2/STAT3/AKT pathways. In conclusion, we documented the anti-CML effects of EGCG in imatinib-sensitive and imatinib-resistant Bcr/Abl+ cells, especially T315I-mutated cells.

Complete Genome Sequence of a Divergent Isolate of Cherry Virus A from Prunus avium in China.

Here, we report the complete genome sequence of a divergent cherry virus A (CVA) isolate (ChYT56) from Prunus avium in China. The genome nucleotide sequence has low identity (80.7%) with a CVA from P. avium (GenBank accession number FN691959) and high identity (97%) with a CVA from P. armeniaca (GenBank accession number LC125634).

Reassessing the Potential of Myb-targeted Anti-cancer Therapy.

Transcription factor MYB is essential for the tumorigenesis of multiple cancers, especially leukemia, breast cancer, colon cancer, adenoid cystic carcinoma and brain cancer. Thus, MYB has been regarded as an attractive target for tumor therapy. However, pioneer studies of antisense oligodeoxynucleotides against MYB, which were launched three decades ago in leukemia therapy, were discontinued because of their unsatisfactory clinical outcomes. In recent years, the roles of MYB in tumor transformation have become increasingly clear. Moreover, the regulatory mechanisms of MYB, such as the vital effects of MYB co-regulators on MYB activity and of transcriptional elongation on MYB expression, have been unveiled. These observations have underpinned novel approaches in inhibiting MYB. This review discusses the structure, function and regulation of MYB, focusing on recent insights into MYB-associated oncogenesis and how MYB-targeted therapeutics can be explored. Additionally, the main MYB-targeted therapies, including novel genetic therapy, RNA interference, microRNAs and low-molecular-weight compounds, which are especially promising inhibitors that target MYB co-regulators and transcriptional elongation, are described, and their prospects are assessed.

C/EBPß contributes to transcriptional activation of long non-coding RNA NEAT1 during APL cell differentiation.

Emerging evidences have shown that long non-coding RNAs (lncRNAs) play critical roles in cancer development and cancer therapy. LncRNA Nuclear Enriched Abundant Transcript 1 (NEAT1) is indispensable during acute promyelocytic leukemia (APL) cell differentiation induced by all-trans retinoic acid (ATRA). However, the precise mechanism of NEAT1 upregulation has not been fully understood. In this study, we performed chromatin immunoprecipitation and luciferase reporter assays to demonstrate that C/EBP family transcription factor C/EBPß bind to and transactivate the promoter of lncRNA NEAT1 through the C/EBPß binding sites both around -54 bp and -1453 bp upstream of the transcription start site. Moreover, the expression of C/EBPß was increased after ATRA treatment, and the binding of C/EBPß in the NEAT1 promoter was also dramatically increased. Finally, knockdown of C/EBPß significantly reduced the ATRA-induced upregulation of NEAT1. In conclusion, C/EBPß directly activates the expression of NEAT1 through binding to the promoter of NEAT1. Knockdown of C/EBPß impairs ATRA-induced transcriptional activation of NEAT1. Our data indicate that C/EBPß contributes to ATRA-induced activation of NEAT1 during APL cell differentiation. Our results enrich our knowledge on the regulation of lncRNAs and the regulatory role of C/EBPß in APL cell differentiation.

Preservation of neuronal functions by exosomes derived from different human neural cell types under ischemic conditions.

Stem cell-based therapies have been reported in protecting cerebral infarction-induced neuronal dysfunction and death. However, most studies used rat/mouse neuron as model cell when treated with stem cell or exosomes. Whether these findings can be translated from rodent to humans has been in doubt. Here, we used human embryonic stem cell-derived neurons to detect the protective potential of exosomes against ischemia. Neurons were treated with in vitro oxygen-glucose deprivation (OGD) for 1 h. For treatment group, different exosomes were derived from neuron, embryonic stem cell, neural progenitor cell and astrocyte differentiated from H9 human embryonic stem cell and added to culture medium 30 min after OGD (100 µg/mL). Western blotting was performed 12 h after OGD, while cell counting and electrophysiological recording were performed 48 h after OGD. We found that these exosomes attenuated OGD-induced neuronal death, Mammalian target of rapamycin (mTOR), pro-inflammatory and apoptotic signaling pathway changes, as well as basal spontaneous synaptic transmission inhibition in varying degrees. The results implicate the protective effect of exosomes on OGD-induced neuronal death and dysfunction in human embryonic stem cell-derived neurons, potentially through their modulation on mTOR, pro-inflammatory and apoptotic signaling pathways.

Further insight into genetic variation and haplotype diversity of Cherry virus A from China.

Cherry virus A (CVA) infection appears to be prevalent in cherry plantations worldwide. In this study, the diversity of CVA isolates from 31 cherry samples collected from different orchards around Bohai Bay in northeastern China was analyzed. The complete genome of one of these isolates, ChYT52, was found to be 7,434 nt in length excluding the poly (A) tail. It shares between 79.9-98.7% identity with CVA genome sequences in GenBank, while its RdRp core is more divergent (79.1-90.7% nt identity), likely as a consequence of a recombination event. Phylogenetic analysis of ChYT52 genome with CVA genomes in Genbank resulted in at least 7 major clusters plus additional 5 isolates alone at the end of long branches suggesting the existence of further phylogroups diversity in CVA. The genetic diversity of Chinese CVA isolates from 31 samples and GenBank sequences were analyzed in three genomic regions that correspond to the coat protein, the RNA-dependent RNA polymerase core region, and the movement protein genes. With few exceptions likely representing further recombination impact, the trees various trees are largely congruent, indicating that each region provides valuable phylogenetic information. In all cases, the majority of the Chinese CVA isolates clustering in phylogroup I, together with the X82547 reference sequence from Germany. Statistically significant negative values were obtained for Tajima's D in the three genes for phylogroup I, suggesting that it may be undergoing a period of expansion. There was considerable haplotype diversity in the individual samples and more than half samples contained genetically diverse haplotypes belonging to different phylogroups. In addition, a number of statistically significant recombination events were detected in CVA genomes or in the partial genomic sequences indicating an important contribution of recombination to CVA evolution. This work provides a foundation for elucidation of the epidemiological characteristics and evolutionary history of CVA populations.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Ameliorates Hippocampal Synaptic Impairment after Transient Global Ischemia.

Recent studies have found that administration of stem cells or extracellular vehicles (EVs) derived from stem cells exert neuroprotective effects after transient global ischemia. However, the underlying mechanisms of this effect remain unclear, especially at the level of synaptic functions. In this study, we compared the suppressive effects on cyclooxygenase-2 (COX-2) upregulation by EVs derived from bone marrow mesenchymal stem cells (BMSC-EV), adipose tissue MSC (AdMSC-EV) and serum (serum-EV). Then we examined whether BMSC-EVs could restore functional integrity of synaptic transmission and plasticity. Mice were randomly assigned to four groups: sham, sham with EV treatment, ischemia and ischemia with EV treatment. EVs were administered by intracerebroventricular injection (ICVI). We examined the consequence of transient global ischemia on pre- and post-synaptic functions of the hippocampal CA3-CA1 synapses at basal level, and long-term potentiation (LTP), an activity-dependent form of synaptic plasticity. Then we tested the therapeutic effects of EVs on these synaptic deficits. Meanwhile, Morris water maze (MWM) test was performed to examine the efficacy of EVs in rescuing ischemia-induced impairments in spatial learning and memory. EV treatment significantly restored impaired basal synaptic transmission and synaptic plasticity, and improved spatial learning and memory compared with the control group. In addition, EVs significantly inhibited ischemia-induced pathogenic expression of COX-2 in the hippocampus. EVs exert ameliorating effects on synaptic functions against transient global cerebral ischemia, which may be partly attributed to suppression of COX-2 pathogenic expression.

A TET2 rs3733609 C/T genotype is associated with predisposition to the myeloproliferative neoplasms harboring JAK2(V617F) and confers a proliferative potential on erythroid lineages.

Common germline single-nucleotide polymorphisms (SNPs) at JAK2 locus have been associated with Myeloproliferative neoplasms (MPN). And, the germline sequence variant rs2736100 C in TERT is related to risk of MPN, suggesting a complex association between SNPs and the pathogenesis of MPN. Our previous study (unpublished data) showed that there was a high frequency distribution in rs3733609 C/T genotype at Ten-Eleven Translocation 2 (TET2) locus in one Chinese familial primary myelofibrosis. In the present study, we evaluate the role and clinical significance of rs3733609 C/T genotype in JAK2V617F-positive sporadic MPN (n = 181). TET2 rs3733609 C/T genotype had a higher incidence (13.81%; 25/181) in JAK2V617F-positive sporadic MPN patients than that in normal controls (n = 236) (6.35%; 15/236), which was predisposing to MPN (odds ratio(OR) = 2.361; P = 0.01). MPN patients with rs3733609 C/T genotype had increased leukocyte and platelets counts, elevated hemoglobin concentration in comparison with T/T genotype. Thrombotic events were more common in MPN patients with rs3733609 C/T than those with T/T genotype (P < 0.01). We confirmed that rs3733609 C/T genotype downregulated TET2 mRNA transcription, and the mechanism may be involved in a disruption of the interaction between CCAAT/enhancer binding protein alpha (C/EBPA) and TET2 rs3733609 C/T locus.TET2 rs3733609 C/T genotype stimulated the erythroid hematopoiesis in MPN patients. Altogether, we found a novel hereditary susceptible factor-TET2 rs3733609 C/T variant for the development of MPN, suggesting the variant may be partially responsible for the pathogenesis and accumulation of MPN.

Icaritin suppresses multiple myeloma, by inhibiting IL-6/JAK2/STAT3.

Icaritin is an active prenylflavonoid derived from Epimedium genus, a traditional Chinese medicine. Icaritin has a wide range of pharmacological and biological activities, including cardiovascular function improvement, hormone regulation and antitumor activity. Here, we investigated the effect of icaritin on multiple myeloma (MM) in vitro and in vivo. Icaritin inhibited cell growth of MM cell line and primary MM cells. In contrast, icaritin had low or no cytotoxic effect on normal hematopoiesis. We also demonstrated that in MM xenograft mouse models, icaritin suppressed tumor growth and decreased serum IL-6 and IgE levels, but did not show adverse reactions such as body weight loss. The anti-MM activity of icaritin was mainly mediated by inhibiting IL-6/JAK2/STAT3 signaling. We suggest that icaritin can be further tested in clinical trials in MM.

Clinical significance of Treg cell frequency in acute myeloid leukemia.

This study was designed to investigate the clinical significance of peripheral blood CD4(+) CD25(+) CD127 low-regulatory T (T(reg)) cells in acute myeloid leukemia (AML) patients. T(reg) cells in the peripheral blood of 80 AML patients and 35 age-matched healthy controls were counted by flow cytometry. Correlations between the frequency of circulating T(reg) cells and disease status, treatment outcome, or prognosis were evaluated. The percentages of T(reg) cells in patients at diagnosis and during refractory/relapse were significantly higher than that in healthy controls. There was no significant difference in the percentages of T(reg) cells between patients in remission and healthy controls. After six cycles of chemotherapy, the percentage of T(reg) cells in patients who achieved complete remission was significantly lower than that in patients at diagnosis, but there was no difference in T(reg) frequency between refractory/relapse patients and patients at diagnosis. T(reg) cells in the peripheral blood of AML patients may play a suppressive role in host antitumor immune response. The frequency of T(reg) cells in peripheral blood may thus be used as a biomarker for predicting sensitivity to chemotherapy and prognosis of AML patients. Additionally, T(reg) number in peripheral blood could be used to monitor disease status and evaluate disease progression.

Analysis of clinical and laboratory characteristics in 42 patients with thrombotic thrombocytopenic purpura from a single center in China.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease characterized by microvascular platelet deposition and thrombus formation with resulting microangiopathic hemolytic anemia. Deficiency of the von Willebrand factor cleavage protease, also known as ADAMTS 13, has been implicated as an important etiological factor in TTP. Little studies were obtained on Chinese patients with TTP until now. Our aim was to analyze the clinical features, outcome and laboratory characteristics of Chinese TTP patients, and determine whether plasma ADAMTS 13 activity is decreased in TTP and its diagnostic value for TTP. Forty-two TTP patients (29 females; 13 males) admitted to our hospital from 1998 to 2010 were analyzed. There were 34 patients (81%) with the triad of TTP, including hemolytic anemia, thrombocytopenia and neurologic abnormalities; 7 (16.7%) had the classical pentad of TTP. Major etiologic factors were acquired autoimmunological abnormalities (31%); no familial TTP was identified in this series. The schistocytes of peripheral blood smears were present in all cases with a mean frequency of 4.6% (range from 0.3% to 13.4%). Plasma ADAMTS 13 activity was determined in 22 patients with the FRET-vWF86 assay. Only 4 idiopathic TTP patients (18.2%) had severe ADAMTS 13 deficiency (activity<10%); 9 (40.9%) had moderate decrease of ADAMTS 13 activity (activity: 10-40%); another 9 (40.91%) had normal ADAMTS 13 activity (>40%). T lymphocyte subpopulation was measured in 23 TTP patients with FACS Calibur; 14 of the 23 (60.9%) had significantly decreased CD4 cells count and CD4/CD8 ratio, suggesting cellular immune dysfunction may be involved in the pathogenesis of TTP. In the studies, plasmapheresis is the main therapeutic method. 26 of 31 patients (83.9%) accepting plasmapheresis achieved complete remission; those patients who only underwent plasma infusion had low remission rate (18.2%) and high mortality (9/11; 81.8%). Four patients with packed RBC infusion manifested transient exacerbation of neurologic or psychiatric symptoms. In conclusion, the diagnosis of TTP in China is still based on clinical features including evidence of microangiopathic hemolysis. Severe ADAMTS 13 activity deficiency might be a valuable indicator for idiopathic TTP diagnosis. Further studies are needed to determine the real value of ADAMTS 13 activity for TTP diagnosis and whether T lymphocytes subset dysregulation plays important role in TTP pathogenesis.