A concise, practical guide to diagnostic assessment for mast cell activation disease

As recognition of mast cell (MC) involvement in a range of chronic inflammatory disorders has increased, diagnosticians’ suspicions of MC activation disease (MCAD) in their chronically mysteriously inflamed patients have similarly increased. It is now understood that the various forms of systemic mastocytosis - diseases of inappropriate activation and proliferation of MCs seemingly driven by a small set of rare, usually constitutively activating mutations in assorted MC regulatory elements - comprise merely the tip of the MCAD iceberg, whereas the far larger and far more clinically heterogeneous (and thus more difficult to recognize) bulk of the iceberg consists of assorted forms of MC activation syndrome (MCAS) which manifest little to no abnormal MC proliferation and may originate from a far more heterogeneous set of MC mutations. It is reasonable to suspect MCAD when symptoms and signs of MC activation are present and no other diagnosis better accounting for the full range of findings is present. Initial laboratory assessment should include not only routine blood counts and serum chemistries but also a serum total tryptase level, which helps direct further evaluation for mastocytosis vs MCAS. Appropriate tissue examinations are needed to diagnose mastocytosis, while elevated levels of relatively specific mast cell mediators are sought to support diagnosis of MCAS. Whether assessing for mastocytosis or MCAS, testing is fraught with potential pitfalls which can easily yield false negatives leading to erroneous rejection of diagnostic consideration of MCAD in spite of a clinical history highly consistent with MCAD. Efforts at accurate diagnosis of MCAD are worthwhile, as many patients then respond well to appropriately directed therapeutic efforts.

Another look at the life of a neutrophil

Neutrophils are considered as the privates of the innate immune system. They are born in the bone marrow, migrate to the tissues where they kill putative intruders. After their job they are quickly removed from the battlefield by macrophages. This view of a predetermined pathway fitted nicely in their short lifespan of 5 h. However, recent studies indicated that their lifespan was in the order of several days. Recently, it became clear that neutrophils have functions beyond killing of pathogens. The reported half-life of 5 h is hardly compatible with those functions. Moreover, the organism actively invests in rescuing primed neutrophils from clearance by the body. It appears that their half-life is highly dependent on the method used to measure their life span. Here, we discuss the literature and show that neutrophils compartmentalize which could explain partially the differences reported for their lifespan. Moreover, the methodology to label neutrophils ex-vivo could have similar deteriorating effects on their lifespan as found for transfused red blood cells.

Aspirin responsive platelet thrombophilia in essential thrombocythemia and polycythemia vera

Essential thrombocythemia (ET) and polycythemia vera (PV) frequently present with erythromelalgia and acrocyanotic complications, migraine-like microvascular cerebral and ocular transient ischemic attacks (MIAs) and/or acute coronary disease. The spectrum of MIAs in ET range from poorly localized symptoms of transient unsteadiness, dysarthria and scintillating scotoma to focal symptoms of transient monocular blindness, transient mono- or hemiparesis or both. The attacks all have a sudden onset, occur sequentially rather than simultaneously, last for a few seconds to several minutes and are usually associated with a dull, pulsatile or migraine-like headache. Increased hematocrit and blood viscosity in PV patients aggravate the microvascular ischemic syndrome of thrombocythemia to major arterial and venous thrombotic complications. Phlebotomy to correct hematocrit to normal in PV significantly reduces major arterial and venous thrombotic complications, but fails to prevent the platelet-mediated erythromelalgia and MIAs. Complete long-term relief of the erythromelalgic microvascular disturbances, MIAs and major thrombosis in ET and PV patients can be obtained with low dose aspirin and platelet reduction to normal, but not with anticoagulation. Skin punch biopsies from the erythromelalgic area show fibromuscular intimal proliferation of arterioles complicated by occlusive platelet-rich thrombi leading to acrocyanotic ischemia. Symptomatic ET patients with erythromelalgic microvascular disturbances have shortened platelet survival, increased platelet activation markers β-thromboglobulin (β-TG), platelet factor 4 (PF4) and thrombomoduline (TM), increased urinary thromboxane B2 (TXB2) excretion, and no activation of the coagulation markers thrombin fragments F1+2 and fibrin degradation products. Inhibition of platelet cyclooxygenase (COX1) by aspirin is followed by the disappearance and no recurrence of microvascular disturbances, increase in platelet number, correction of the shortened platelet survival times to normal, and reduction of increased plasma levels of β-TG, PF4, TM and urinary TXB2 excretion to normal. These results indicate that platelet-mediated fibromuscular intimal proliferation and platelet-rich thrombi in the peripheral, cerebral and coronary end-arterial microvasculature are responsible for the erythromelalgic ischemic complications, MIAs and splanchnic vein thrombosis. Baseline platelet P-selectin levels and arachidonic acid induced COX1 mediated platelet activation showed a highly significant increase of platelet P-selectin expression (not seen in ADP and collagen stimulated platelets), which was significantly higher in JAK2^V617F mutated compared to JAK2 wild type ET.

Current approach to relapsed acute lymphoblastic leukemia in children

Recurrent acute lymphoblastic leukaemia (ALL) is a common disease for pediatric oncologists and accounts for more deaths from cancer in children than any other malignancy. Although most patients achieve a second remission, about 50% of relapsed ALL patients do not respond to salvage therapy or suffer a second relapse and most children with relapse die. Treatment must be tailored after relapse of ALL, since outcome will be influenced by well-established prognostic features, including the timing and site of disease recurrence, the disease immunophenotype, and early response to retrieval therapy in terms of minimal residual disease (MRD). After reinduction chemotherapy, high risk (HR) patients are clear candidates for allogeneic stem cell transplantation (SCT) while standard risk patients do better with conventional chemotherapy and local therapy. Early MRD response assessment is currently applied to identify those patients within the more heterogeneous intermediate risk group who should undergo SCT as consolidation therapy. Recent evidence suggests distinct biological mechanisms for early vs late relapse and the recognition of the involvement of certain treatment resistance related genes as well cell cycle regulation and B-cell development genes at relapse, provides the opportunity to search for novel target therapies.

Oxidative alterations in sickle cell disease: Possible involvement in disease pathogenesis

Sickle cell disease (SCD) is the first molecular disease in the literature. Although the structural alteration and dysfunction of the sickle hemoglobin (HbS) are well understood, the many factors modifying the clinical signs and symptoms of the disease are under investigation. Besides having an abnormal electrophoretic mobility and solubility, HbS is unstable. The autooxidation rate of the abnormal HbS has been reported to be almost two times of the normal. There are two more components of the oxidative damage in SCD: Free radical induced oxidative damage during vaso-occlusion induced ischemia-reperfusion injury and decreased antioxidant capacity in the erythrocyte and in the circulation. We will discuss the effects of oxidative alterations in the erythrocyte and in the plasma of SCD patients in this review.

P2X7 receptor activation causes phosphatidylserine exposure in canine erythrocytes

AIM

To determine if activation of the ATP-gated P2X7 receptor channel induces phosphatidylserine (PS) exposure in erythrocytes from multiple dog breeds.

METHODS

Peripheral blood was collected from 25 dogs representing 13 pedigrees and seven crossbreeds. ATP-induced PS exposure on canine erythrocytes in vitro was assessed using a flow cytometric Annexin V binding assay.

RESULTS

ATP induced PS exposure in erythrocytes from all dogs studied. ATP caused PS exposure in a concentration-dependent manner with an EC₅₀ value of 395 μmol/L. The non-P2X7 agonists, ADP or AMP, did not cause PS exposure. The P2X7 antagonist, AZ10606120, but not the P2X1 antagonist, NF449, blocked ATP-induced PS exposure.

CONCLUSION

The results indicate that ATP induces PS exposure in erythrocytes from various dog breeds and that this process is mediated by P2X7 activation.

PVSG and WHO vs European Clinical, Molecular and Pathological Criteria for prefibrotic myeloproliferative neoplasms

The Polycythemia Vera Study Group (PVSG), World Health Organization (WHO) and European Clinical, Molecular and Pathological (ECMP) classifications agree upon the diagnostic criteria for polycythemia vera (PV) and advanced primary myelofibrosis (MF). Essential thrombocythemia (ET) according to PVSG and 2007/2008 WHO criteria comprises three variants of JAK2^V617F mutated ET when the ECMP criteria are applied. These include normocellular ET, hypercellular ET with features of early PV (prodromal PV), and hypercellular ET due to megakaryocytic, granulocytic myeloproliferation (ET.MGM). Evolution of prodromal PV into overt PV is common. Development of MF is rare in normocellular ET (WHO-ET) but rather common in hypercellular ET.MGM. The JAK2^V617F mutation burden in heterozygous mutated normocellular ET and in heterozygous/homozygous or homozygous mutated PV and ET.MGM is of major prognostic significance. JAK2/MPL wild type ET associated with prefibrotic primary megakaryocytic and granulocytic myeloproliferation (PMGM) is characterized by densely clustered immature dysmorphic megakaryocytes with bulky (bulbous) hyperchromatic nuclei, which are never seen in JAK2^V617F mutated ET, and PV and also not in MPL⁵¹⁵ mutated normocellular ET (WHO-ET). JAK2^V617 mutation burden, spleen size, LDH, circulating CD34⁺ cells, and pre-treatment bone marrow histopathology are mandatory to stage the myeloproliferative neoplasms ET, PV, PMGM for proper prognosis assessment and therapeutic implications. MF itself is not a disease because reticulin fibrosis and reticulin/collagen fibrosis are secondary responses of activated polyclonal fibroblasts to cytokines released from the clonal myeloproliferative granulocytic and megakaryocytic progenitor cells in ET.MGM, PV and PMGM.

Pseudohemophilia of Erik von Willebrand caused by homozygous one nucleotide deletion in exon 18 of the VW-factor gene

The original description of a novel severe bleeding disorder as “Hereditary Pseudohemophilia” by Erik von Willebrand can currently be labelled as von Willebrand disease (VWD) type 3. VWD type 3 is autosomal recessive caused by homozygous or double heterozygous null mutations in the von Willebrand factor (VWF) gene and typically characterized by prolonged bleeding time and APTT, FVIII: C levels below 2%, undetectable VWF: Ag, VWF: RCo and VWF: CB and absence of ristocetin induced platelet aggregation (RIPA). Autosomal recessive von Willebrand disease type 3 VWD with virtual complete VWF deficiency are homozygous or compound heterozygous for two null alleles (gene deletions, stop codons, frame shift mutations, splice site mutations, and absence of mRNA). Reports on severe recessive VWD compound heterozygous for a null allele and a missense mutation and homozygous or double heterozygous for missense mutations are associated with very low but measurable FVIII and VWF: Ag and should be reclassified as severe recessive type 1 VWD. Homozygous missense or compound missense/null mutations related to recessive severe type 1 VWD have been indentified in the VWF prosequence D1 and D2 domains, the D4, B1-3, C1-2 domains, and only a very few in the dimmerization site (D3 domain). The detection of even tiny amounts of VWF: Ag after desmopressin acetate (DDAVP) or in hidden sites like platelets allows the differentiation between patients with VWD type 3 and homozygous or double heterozygous recessive severe type 1. Carriers of a null allele related to VWD type 3 or a missense mutation related with severe recessive type 1 VWD may present with mild VWD with low penetrance of bleeding in particular when associated with blood group O. Heterozygous obligatory carriers (OC) of a null mutation or a missense mutation related to recessive VWD type 3 or severe type 1 both present with asymptomatic or mild VWD type 1 in particular when associated with blood group O. The response to DDAVP of OC of either a nonsense or a missense mutation appears to be abnormal and diagnostic with a 3-times higher response of FVIII: C as compared to VWF: Ag. In contrast, the responses to DDAVP of FVIII: C and VWF: Ag are equally good in individuals with low VWF levels related to blood group O and a normal VWF gene and protein (pseudo-VWD). These observations are completely in line with and extend the original observations of von Willebrand in a large family with VWD type 3 and asymptomatic or mild true type 1 VWD in OC.

European vs 2015-World Health Organization clinical molecular and pathological classification of myeloproliferative neoplasms

The BCR/ABL fusion gene or the Ph¹-chromosome in the t(9;22)(q34;q11) exerts a high tyrokinase acticity, which is the cause of chronic myeloid leukemia (CML). The 1990 Hannover Bone Marrow Classification separated CML from the myeloproliferative disorders essential thrombocythemia (ET), polycythemia vera (PV) and chronic megakaryocytic granulocytic myeloproliferation (CMGM). The 2006-2008 European Clinical Molecular and Pathological (ECMP) criteria discovered 3 variants of thrombocythemia: ET with features of PV (prodromal PV), “true” ET and ET associated with CMGM. The 2008 World Health Organization (WHO)-ECMP and 2014 WHO-CMP classifications defined three phenotypes of JAK2^V617F mutated ET: normocellular ET (WHO-ET), hypercelluar ET due to increased erythropoiesis (prodromal PV) and ET with hypercellular megakaryocytic-granulocytic myeloproliferation. The JAK2^V617F mutation load in heterozygous WHO-ET is low and associated with normal life expectance. The hetero/homozygous JAK2^V617F mutation load in PV and myelofibrosis is related to myeloproliferative neoplasm (MPN) disease burden in terms of symptomatic splenomegaly, constitutional symptoms, bone marrow hypercellularity and myelofibrosis. JAK2 exon 12 mutated MPN presents as idiopathic eryhrocythemia and early stage PV. According to 2014 WHO-CMP criteria JAK2 wild type MPL⁵¹⁵ mutated ET is the second distinct thrombocythemia featured by clustered giant megakaryocytes with hyperlobulated stag-horn-like nuclei, in a normocellular bone marrow consistent with the diagnosis of “true” ET. JAK2/MPL wild type, calreticulin mutated hypercellular ET appears to be the third distinct thrombocythemia characterized by clustered larged immature dysmorphic megakaryocytes and bulky (bulbous) hyperchromatic nuclei consistent with CMGM or primary megakaryocytic granulocytic myeloproliferation.

First contributors in the history of leukemia

While the modern era of leukemia chemotherapy began recently, the recognition of leukemias has been mainly recorded in the second part of the nineteenth century. This brief historic review reports the first descriptions of the disease and the major advances in its history from its roots to the beginning of the twentieth century. Although most treatments for leukemia were ineffective until the middle of the twentieth century, it seemed of interest to review some pertinent exemples of the evolution in the knowledge of this disease (relied upon chronology as an organizing framework, while stressing the importance of themes), since our current knowledge about leukemia is still mainly based on the first accounts of scientific and medical discovery. Early in the nineteenth century, a small number of cases of patients with uncommon or peculiar alterations of the blood were published. Of the cases, four might suggest symptoms of chronic leukemia. The first published case was the detailed report prepared by John Hughes Bennett in the “Edinburgh Medical and Surgical Journal” October 1845. Leukemia gradually became accepted as a distinct disease and published case reports grew in number. Concomitantly, clinical and pathological description of the disease became more detailed.

Aspirin cures erythromelalgia and cerebrovascular disturbances in JAK2-thrombocythemia through platelet-cycloxygenase inhibition

Hypersensitive (sticky) platelets in JAK2-mutated essential thrombocythemia (ET) and polycythemia vera (PV) with thrombocythemia spontaneously activate at high shear in arterioles, secrete their inflammatory prostaglandin endoperoxides and induce platelet-mediated arteriolar fibromuscular intimal proliferation. Constitutively activated JAK2 mutated hypersensitive (sticky) platelets spontaneously aggregate at high shear in the endarteriolar circulation as the cause of aspirin responsive erythromelalgia and platelet arterial thrombophilia in JAK2-mutated thrombocythemia patients. Increased production of prostglandin endoperoxides E2 and thromboxane A2 released by activated sticky platelets in arterioles account for redness warmth and swelling of erythromelalgia and platelet derived growth factor can readily explain the arteriolar fibromuscular intimal proliferation. Von Willebrand factor (VWF) platelet rich occlusive thrombi in arterioles are the underlying pathobiology of erythromelalgic acrocyanosis, migraine-like transient cerebral attacks (MIAs), acute coronary syndromes and abdominal microvscular ischemic events. Irreversible platelet cyco-oxygenase inhibition by aspirin cures the erythromelalgia, MIAs and microvascular events, corrects shortened platelet survival to normal, and returns increased plasma levels of beta-TG, platelet factor 4, thrombomoduline and urinary thromboxane B2 excretion to normal in symptomatic JAK2-thrombocythemia patients. In vivo activation of sticky platelets and VWF-platelet aggregates account for endothelial cell activation to secrete thrombomoduline and sVCAM followed by occlusion of arterioles by VWF-rich platelet thrombi in patients with erythromelalgic thrombotic thrombocythemia (ETT) in ET and PV patients. ETT is complicated by spontaneous hemorrhagic thrombocythemia (HT) or paradoxical ETT/HT due to acquired von Willebrand disease type 2A at platelet counts above 1000 × 10⁹/L and disappears by cytoreduction of platelets to normal (< 400 × 10⁹/L).

Cost of allogeneic blood transfusion

Blood is a scarce and costly resource to society. Therefore, it is important to understand the costs associated with blood, blood components, and blood transfusions. Previous studies have attempted to account for the cost of blood but, because of different objectives, perspectives, and methodologies, they may have underestimated the true (direct and indirect) costs associated with transfusions. Recognizing these limitations, a panel of experts in blood banking and transfusion medicine gathered at the Cost of Blood Consensus Conference to identify a set of key elements associated with whole blood collection, transfusion processes, follow-up, and to establish a standard methodology in estimating costs. Activity-based costing (ABC), the proposed all-inclusive reference methodology, is expected to produce standard and generalizable estimates of the cost of blood transfusion, and it should prove useful to payers, buyers, and society (all of whom bear the cost of blood). In this article, we argue that the ABC approach should be adopted in future cost-of-transfusion studies. In particular, we address the supply and demand dilemma associated with blood and blood components; evaluate the economic impact of transfusion-related adverse outcomes on overall blood utilization; discuss hemovigilance as it contributes not to the expense, but also the safety of transfusion; review previous cost-of-transfusion studies; and summarize the ABC approach and its utility as a methodology for estimating transfusion costs.

Current approach to disseminated intravascular coagulation related to sepsis - organ failure type

Disseminated intravascular coagulation (DIC) is a syndrome characterized by the systemic activation of blood clotting, which generates large amount of intravascular thrombin and fibrin. Various diseases may cause acceleration of the clotting cascade, inactivate the endogenous anticoagulants and modify fibrinolysis, having thus the formation of micro thrombi in the systemic circulation. The abnormalities in the hemostatic system in patients with DIC result from the sum of pathways that generate both hypercoagulability and augmented fibrinolysis. When the hypercoagulability state prevails, the main manifestation is organic failure. This subtype of DIC is often referred as “organ impairment” type, frequently seen in patients suffering from severe sepsis. To identify the underlying infection, early initiation of culture-based antimicrobial treatment, and to resolve any infection source promptly are keystone actions of DIC related to sepsis prevention and treatment. These should be combined with specific treatment related to each DIC subtype. In the context of septic shock, DIC is associated to increased severity, greater number and seriousness of organ failures, more frequent side-effects from treatment itself, and worse outcomes. Therefore, we ought to review the information available in the literature about approach and management of DIC in severe sepsis.

Current viewpoints on platelet contribution to inflammation

Inflammation is an underlying feature of a variety of human diseases. Because inflammatory diseases are a major cause of morbidity and mortality in developed countries, understanding the interaction of the most important factors involved is an important challenge. Although platelets are widely recognized as having a critical role in primary hemostasis and thrombosis, basic and clinical evidence increasingly identifies these enucleated cells as relevant modulators, as both effector and target cells, of the inflammatory response. The cross-talk between platelets, endothelial cells and leukocytes in the inflammatory milieu mat be seen as a double-edged sword which functions not only as an effective first-line defense mechanism but may also lead to organ failure and death in the absence of counter-regulation systems. The molecular mechanisms involved in the reciprocal activation of platelets, endothelial cells and leukocytes are beginning to be elucidated. In the light of the existing data from experimental and clinical studies it is conceivable that platelet adhesion molecules and platelet mediators provide promising targets for novel therapeutic strategies in inflammatory diseases. The potentially adverse effects of these approaches need to be carefully addressed and monitored, including alterations in hemostasis and coagulation and particularly the impairment of host defense mechanisms, given the recently identified pivotal role of platelets in pathogen recognition and bacterial trapping. In this review we discuss the most important recent advances in research into the cross-talk between platelets and vascular cells during inflammation and the clinical consequences of these interactions.

Treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis: Study protocol of a prospective pilot study

In this manuscript, a number of debatable issues related to the diagnosis and treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis (EBV-HLH) will be addressed. Considering the heterogeneous nature of EBV-HLH, diagnostic efforts are required to clarify the precise nature of the disease at diagnosis, the number of EBV genome copies in peripheral blood, and localization of the EBV genome in lymphoid cells (B, T, or natural killer cells). Although the majority of cases of EBV-HLH develop without evidence of immunodeficiency, some cases have been found to be associated with chronic active EBV infection, genetic diseases such as X-linked lymphoproliferative disease (XLP, type 1, or type 2), or familial HLH (FHL, types 2-5). Due to such background heterogeneity, the therapeutic results of EBV-HLH have also been found to vary. Patients have been found to respond to corticosteroids alone or an etoposide-containing regimen, whereas other patients require hematopoietic stem cell transplantation. Thus, decision-making for optimal treatment of EBV-HLH and its eventual outcome requires evaluation in consideration of the precise nature of the disease. A protocol for a pilot study on the treatment of patients with EBV-HLH is presented here.

Identifying changes in punitive transcriptional factor binding sites from regulatory single nucleotide polymorphisms that are significantly associated with disease or sickness

AIM

To identify punitive transcriptional factor binding sites (TFBS) from regulatory single nucleotide polymorphisms (rSNPs) that are significantly associated with disease.

METHODS

The genome-wide association studies have provided us with nearly 6500 disease or trait-predisposing SNPs where 93% are located within non-coding regions such as gene regulatory or intergenic areas of the genome. In the regulatory region of a gene, a SNP can change the DNA sequence of a transcriptional factor (TF) motif and in turn may affect the process of gene regulation. SNP changes that affect gene expression and impact gene regulatory sequences such as promoters, enhancers, and silencers are known as rSNPs. Computational tools can be used to identify unique punitive TFBS created by rSNPs that are associated with disease or sickness. Computational analysis was used to identify punitive TFBS generated by the alleles of these rSNPs.

RESULTS

rSNPs within nine genes that have been significantly associated with disease or sickness were used to illustrate the tremendous diversity of punitive unique TFBS that can be generated by their alleles. The genes studied are the adrenergic, beta, receptor kinase 1, the v-akt murine thymoma viral oncogene homolog 3, the activating transcription factor 3, the type 2 demodkinase gene, the endothetal Per-Arnt-Sim domain protein 1, the lysosomal acid lipase A, the signal Transducer and Activator of Transcription 4, the thromboxane A2 receptor and the vascular endothelial growth factor A. From this sampling of SNPs among the nine genes, there are 73 potential unique TFBS generated by the common alleles compared to 124 generated by the minor alleles indicating the tremendous diversity of potential TFs that are capable of regulating these genes.

CONCLUSION

From the diversity of unique punitive binding sites for TFs, it was found that some TFs play a role in the disease or sickness being studied.

Clinical approach to diarrheal disorders in allogeneic hematopoietic stem cell transplant recipients

Diarrhea is a common complication of allogeneic hematopoietic stem cell transplant (HSCT), with an average incidence of approximately 40%-50%. A wide variety of etiologies can contribute to diarrhea in HSCT patients, including medication-induced mucosal inflammation, infections, graft-vs-host disease and cord colitis syndrome in umbilical cord blood transplant. Clinical manifestations can vary from isolated diarrheal episodes, to other organ involvement including pneumonia or myocarditis, and rarely multiorgan failure. The approach for diagnosis of diarrheal disorders in HSCT patients depends on the most likely cause. Given the risk of life-threatening conditions, the development of clinically significant diarrhea requires prompt evaluation, supportive care and specific therapy, as indicated. Serious metabolic and nutritional disturbances can happen in HSCT patients, and may even lead to mortality. In this review, we aim to provide a practical approach to diagnosis and management of diarrhea in the post-transplant period.

Allogeneic stem cell transplantation in chronic myeloid leukemia patients: Single center experience

Chronic myeloid leukemia (CML) is a myeloproliferative disease which leads the unregulated growth of myeloid cells in the bone marrow. It is characterized by the presence of Philadelphia chromosome. Reciprocal translocation of the ABL gene from chromosome 9 to 22 t (9; 22) (q34; q11.2) generate a fusion gene (BCR-ABL). BCR-ABL protein had constitutive tyrosine kinase activity that is a primary cause of chronic phase of CML. Tyrosine kinase inhibitors (TKIs) are now considered standard therapy for patients with CML. Even though, successful treatment with the TKIs, allogeneic stem cell transplantation (ASCT) is still an important option for the treatment of CML, especially for patients who are resistant or intolerant to at least one second generation TKI or for patients with blastic phase. Today, we know that there is no evidence for increased transplant-related toxicity and negative impact of survival with pre-transplant TKIs. However, there are some controversies about timing of ASCT, the optimal conditioning regimens and donor source. Another important issue is that BCR-ABL signaling is not necessary for survival of CML stem cell and TKIs were not effective on these cells. So, ASCT may play a role to eliminate CML stem cells. In this article, we review the diagnosis, management and treatment of CML. Later, we present our center’s outcomes of ASCT for patients with CML and then, we discuss the place of ASCT in CML treatment in the TKIs era.

A concise, practical guide to diagnostic assessment for mast cell activation disease

As recognition of mast cell (MC) involvement in a range of chronic inflammatory disorders has increased, diagnosticians’ suspicions of MC activation disease (MCAD) in their chronically mysteriously inflamed patients have similarly increased. It is now understood that the various forms of systemic mastocytosis - diseases of inappropriate activation and proliferation of MCs seemingly driven by a small set of rare, usually constitutively activating mutations in assorted MC regulatory elements - comprise merely the tip of the MCAD iceberg, whereas the far larger and far more clinically heterogeneous (and thus more difficult to recognize) bulk of the iceberg consists of assorted forms of MC activation syndrome (MCAS) which manifest little to no abnormal MC proliferation and may originate from a far more heterogeneous set of MC mutations. It is reasonable to suspect MCAD when symptoms and signs of MC activation are present and no other diagnosis better accounting for the full range of findings is present. Initial laboratory assessment should include not only routine blood counts and serum chemistries but also a serum total tryptase level, which helps direct further evaluation for mastocytosis vs MCAS. Appropriate tissue examinations are needed to diagnose mastocytosis, while elevated levels of relatively specific mast cell mediators are sought to support diagnosis of MCAS. Whether assessing for mastocytosis or MCAS, testing is fraught with potential pitfalls which can easily yield false negatives leading to erroneous rejection of diagnostic consideration of MCAD in spite of a clinical history highly consistent with MCAD. Efforts at accurate diagnosis of MCAD are worthwhile, as many patients then respond well to appropriately directed therapeutic efforts.

Circulating microparticles and microRNAs as players in atherosclerosis

Microparticles (MPs) are extracellular membrane vesicles released from normal, apoptotic and pathological cells following a process of detachment from cells of origin. MPs are typically defined by their size, exposure of phosphatidylserine, the expression of surface antigens, proteins and genetic material, originating from their donor cells, and as important vehicles of intercellular communication across numerous biological processes. MPs contain the major source of systemic RNA including microRNA (miRNA) of which aberrant expression appears to be associated with stage and progression of atherosclerosis. The involvement and influence of miRNA during the onset and progression of atherosclerotic disease have generated a lot of interest in assessing the feasibility of therapeutic regulation of miRNAs to manipulate them with a special focus on cardiovascular disease. We speculate on the future developments of MPs which contain miRNA as new therapeutic targets for proliferative vascular diseases such as atherosclerosis.

Changing insights in the diagnosis and classification of autosomal recessive and dominant von Willebrand diseases 1980-2015

The European Clinical Laboratory and Molecular (ECLM) criteria define 10 distinct Willebrand diseases (VWD): recessive type 3, severe 1, 2C and 2N; dominant VWD type 1 secretion/clearance defect, 2A, 2B, 2E, 2M and 2D; and mild type 1 VWD (usually carriers of recessive VWD). Recessive severe 1 and 2C VWD are characterized by secretion and multimerization defects caused by mutations in the D1-D2 domain. Recessive 2N VWD is a mild hemophilia due to D’-FVIII-von Willebrand factor (VWF) binding site mutations. Dominant 2E VWD caused by heterozygous missense mutations in the D3 domain is featured by a secretion-clearance-multimerization VWF defect. Dominant VWD type 2M due to loss of function mutations in the A1 domain is characterized by decreased ristocetin-induced platelet aggregation and VWF:RCo, normal VWF multimers and VWF:CB, a poor response of VWF:RCo and good response of VWF:CB to desmopressin (DDAVP). Dominant VWD type 2A induced by heterozygous mutations in the A2 domain results in hypersensitivity of VWF for proteolysis by ADAMTS13 into VWF degradation products, resulting in loss of large VWF multimers with triplet structure of each individual VWF band. Dominant VWD type 2B due to a gain of function mutation in the A1 domain is featured by spontaneous interaction between platelet glycoprotein Ib (GPIb) and mutated VWF A1 followed by increased proteolysis with loss of large VWF multimers and presence of each VWF band. A new category of dominant VWD type 1 secretion or clearance defect due to mutations in the D3 domain or D4-C1-C5 domains consists of two groups: Those with normal or smeary pattern of VWF multimers.

Storage lesion: History and perspectives

Red blood cell concentrates (RBCCs) are the major labile blood component transfused worldwide to rescue severe anemia symptoms. RBCCs are frequently stored in additive solutions at 4 °C for up to 42 d, which induces cellular lesion and alters red blood cell metabolism, protein content, and rheological properties. There exists a hot debate surrounding the impact of storage lesion, with some uncertainty regarding how RBCC age may impact transfusion-related adverse clinical outcomes. Several studies show a tendency for poorer outcomes to occur in patients receiving older blood products; however, no clear significant association has yet been demonstrated. Some age-related RBCC alterations prove reversible, while other changes are irreversible following protein oxidation. It is likely that any irreversible damage affects the blood component quality and thus the transfusion efficiency. The present paper aims to promote a better understanding of the occurrence of red blood cell storage lesion, with particular focus on biochemical changes and microvesiculation, through a discussion of the historical advancement of blood transfusion processes.

Tbl3 encodes a WD40 nucleolar protein with regulatory roles in ribosome biogenesis

AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3 (Tbl3).

METHODS: The coding sequence of mouse Tbl3 was cloned from the cDNAs of a promyelocyte cell line by reverse transcription-polymerase chain reaction. Fusion constructs of Tbl3 and enhanced green fluorescent protein (EGFP) were transfected into fibroblasts and examined by fluorescence microscopy to reveal the subcellular localization of tbl3. To search for nucleolar targeting sequences, scanning deletions of Tbl3-EGFP were constructed and transfected into fibroblasts. To explore the possible function of Tbl3, small hairpin RNAs (shRNAs) were used to knock down endogenous Tbl3 in mouse promyelocytes and fibroblasts. The effects of Tbl3 knockdown on ribosomal RNA (rRNAs) synthesis or processing were studied by labeling cells with 5,6-³H-uridine followed by a chase with fresh medium for various periods. Total RNAs were purified from treated cells and subjected to gel electrophoresis and Northern analysis. Ribosome profiling by sucrose gradient centrifugation was used to compare the amounts of 40S and 60S ribosome subunits as well as the 80S monosome. The impact of Tbl3 knockdown on cell growth and proliferation was examined by growth curves and colony assays.

RESULTS: The largest open reading frame of mouse Tbl3 encodes a protein of 801 amino acids (AA) with an apparent molecular weight of 89-90 kilodalton. It contains thirteen WD40 repeats (an ancient protein-protein interaction motif) and a carboxyl terminus that is highly homologous to the corresponding region of the yeast nucleolar protein, utp13. Virtually nothing is known about the biological function of Tbl3. All cell lines surveyed expressed Tbl3 and the level of expression correlated roughly with cell proliferation and/or biosynthetic activity. Using Tbl3-EGFP fusion constructs we obtained the first direct evidence that Tbl3 is targeted to the nucleoli in mammalian cells. However, no previously described nucleolar targeting sequences were found in Tbl3, suggesting that the WD40 motif and/or other topological features are responsible for nucleolar targeting. Partial knockdown (by 50%-70%) of mouse Tbl3 by shRNA had no discernable effects on the processing of the 47S pre-ribosomal RNA (pre-rRNA) or the steady-state levels of the mature 28S, 18S and 5.8S rRNAs but consistently increased the expression level of the 47S pre-rRNA by two to four folds. The results of the current study corroborated the previous finding that there was no detectable rRNA processing defects in zebra fish embryos with homozygous deletions of zebra fish Tbl3. As ribosome production consumes the bulk of cellular energy and biosynthetic precursors, dysregulation of pre-rRNA synthesis can have negative effects on cell growth, proliferation and differentiation. Indeed, partial knockdown of Tbl3 in promyelocytes severely impaired their proliferation. The inhibitory effect of Tbl3 knockdown was also observed in fibroblasts, resulting in an 80% reduction in colony formation. Taken together, these results indicate that Tbl3 is a newly recognized nucleolar protein with regulatory roles at very early stages of ribosome biogenesis, perhaps at the level of rRNA gene transcription.

CONCLUSION: Tbl3 is a newly recognized nucleolar protein with important regulatory roles in ribosome biogenesis.