Virtual-freezing fluorescence imaging flow cytometry with 5-aminolevulinic acid stimulation and antibody labeling for detecting all forms of circulating tumor cells

Circulating tumor cells (CTCs) are precursors to cancer metastasis. In blood circulation, they take various forms such as single CTCs, CTC clusters, and CTC-leukocyte clusters, all of which have unique characteristics in terms of physiological function and have been a subject of extensive research in the last several years. Unfortunately, conventional methods are limited in accurately analysing the highly heterogeneous nature of CTCs. Here we present an effective strategy for simultaneously analysing all forms of CTCs in blood by virtual-freezing fluorescence imaging (VIFFI) flow cytometry with 5-aminolevulinic acid (5-ALA) stimulation and antibody labeling. VIFFI is an optomechanical imaging method that virtually freezes the motion of fast-flowing cells on an image sensor to enable high-throughput yet sensitive imaging of every single event. 5-ALA stimulates cancer cells to induce the accumulation of protoporphyrin (PpIX), a red fluorescent substance, making it possible to detect all cancer cells even if they show no expression of the epithelial cell adhesion molecule, a typical CTC biomarker. Although PpIX signals are generally weak, VIFFI flow cytometry can detect them by virtue of its high sensitivity. As a proof-of-principle demonstration of the strategy, we applied cancer cells spiked in blood to the strategy to demonstrate image-based detection and accurate classification of single cancer cells, clusters of cancer cells, and clusters of a cancer cell(s) and a leukocyte(s). To show the clinical utility of our method, we used it to evaluate blood samples of four breast cancer patients and four healthy donors and identified EpCAM-positive PpIX-positive cells in one of the patient samples. Our work paves the way toward the determination of cancer prognosis, the guidance and monitoring of treatment, and the design of antitumor strategies for cancer patients.

COVID-19 and Thrombosis: Clinical Aspects

In coronavirus disease 2019 (COVID-19), thrombus formation is related to the pathogenesis of acute respiratory distress syndrome (ARDS) and the progression of clinical symptoms. Severe damage to vascular endothelial cells and the associated cytokine storm after SARS-CoV-2 infection cause thrombogenesis and contribute to the development of more severe and unique thromboses compared to other infectious diseases. Thromboses occur more often in critically ill patients. In addition to pulmonary thromboembolism (PE) and deep vein thrombosis, acute myocardial infarction, peripheral arterial thrombosis, and aortic thrombosis have also been reported. In PE, thrombi develop in both pulmonary arteries and alveolar capillaries. These, together with intraalveolar fibrin deposition, interfere with effective gaseous exchange in the lungs and exacerbate the clinical symptoms of ARDS in patients with COVID-19. Pharmacological thromboprophylaxis is recommended for all hospitalized patients to prevent both thrombosis and aggravation of ARDS, and other organ failures. Although the pediatric population is mostly asymptomatic or develops mild disease after SARS-CoV-2 infection, a new inflammatory disorder affecting the cardiovascular system, multisystem inflammatory syndrome in children (MIS-C), has been reported. Similar to Kawasaki disease, acute myocarditis, coronary vasculitis, and aneurysms are typically seen in MISC, although these two are now considered distinct entities. A similar acute myocarditis is also observed in young male adults, in which a hyperinflammatory state after SARS-CoV-2 infection seems to be involved. Several side effects following vaccination against COVID-19 have been reported, including vaccine-induced immune thrombotic thrombocytopenia and acute myocarditis. Although these could be serious and life-threatening, the cases are very rare, thus, the benefits of immunization still outweigh the risks.

Time of Day of Vaccination Does Not Associate With SARS-CoV-2 Antibody Titer Following First Dose of mRNA COVID-19 Vaccine

The immune system exhibits circadian rhythms, and its response to viral infection is influenced by the circadian clock system. Previous studies have reported associations between the time of day of vaccination against COVID-19 and production of anti-SARS-CoV-2 antibody titer. We examined the effect of vaccination time of day on anti-SARS-CoV-2 antibody titer after the first dose of vaccination with the mRNA-1273 (Moderna) COVID-19 vaccine in an adult population. A total of 332 Japanese adults participated in the present study. All participants were not infected with SARS-CoV-2 and had already received the first dose of mRNA-1273 2 to 4 weeks prior to participating in the study. The participants were asked to provide basic demographic characteristics (age, sex, medical history, allergy, medication, and mean sleep duration), the number of days after the first dose of vaccination, and the time of day of vaccination. Blood was collected from the participants, and SARS-CoV-2 antibody titers were measured. Ordinary least square regression was used for assessing the relationship between basic demographic characteristics, number of days after vaccination, time of day of vaccination, and the log₁₀-transformed normalized antibody titer. The least square mean of antibody titers was not associated with the vaccination time and sleep durations. The least square means of antibody titers was associated with age; the antibody titers decreased in people aged 50 to 59 years and 60 to 64 years. The present findings demonstrate that the vaccination time with mRNA-1273 was not associated with the SARS-CoV-2 antibody titer in an adult population, suggesting that these results do not support restricting vaccination to a particular time of day. The present findings may be useful in optimizing SARS-CoV-2 vaccination strategies.

[Thrombosis with Thrombocytopenia Syndrome after ChAdOx1 nCoV-19 vaccination]

A 48-year-old Japanese man who had no previous medical history received his first dose of the ChAdOx1 nCoV-19 vaccine. Ten days after the vaccine administration, he developed a headache. Laboratory results indicated throm-bocytopenia and DIC. A head CT revealed microbleeding in the left parietal lobe. Contrast-enhanced CT showed thrombus in the left transverse sinus and left sigmoid sinus. A brain MRI demonstrated venous hemorrhagic infarction and subarachnoid hemorrhages in the left parietal lobe, and whole-body enhanced CT also revealed portal vein embolism and renal infarction. He was diagnosed with thrombosis with thrombocytopenia syndrome, and was treated according to the guideline. He has been recovering with the treatments. This is the first reported case of TTS associated with the ChAdOx1 nCoV-19 vaccine in Japan.

Aleukemic Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia with E1A3 BCR-ABL1 Fusion Transcript

Right neck swelling and pain occurred in a 49-year-old man. A Blood count showed a slight increase in platelet count without leukemoid reaction. After a biopsy of the cervical mass and bone marrow aspiration, a diagnosis of extramedullary blast crisis (EBC) of chronic myeloid leukemia (CML) was made. Fluorescence in situ hybridization (FISH) analysis showed a BCR-ABL1 fusion signal, but results of real-time polymerase chain reaction (RT-PCR) for major and minor BCR-ABL1 transcripts were negative. We identified a rare e1a3 BCR-ABL1 fusion transcript. Administration of dasatinib resulted in disappearance of the extramedullary tumor. This is the first reported case of CML-EBC with e1a3 transcript. An aleukemic extramedullary tumor can be the initial presentation of CML.

[Novel disease entities due to antiplatelet factor 4 antibodies: HIT, aHIT, and VITT]

Antiplatelet factor 4 (PF4) antibodies, also known as anti-PF4/heparin complex antibodies, are measured to diagnose heparin-induced thrombocytopenia (HIT). In HIT, anti-PF4 antibodies induced by heparin exposure cause thrombocytopenia and thrombosis. However, in recent years, autoimmune HIT (aHIT) that develops without heparin exposure has been getting attention. In 2021, anti-PF4 antibodies were reported to cause the fatal vaccine-induced immune thrombotic thrombocytopenia (VITT) that developed after adenoviral vector vaccination for COVID-19. HIT, aHIT, and VITT are considered to be caused by anti-PF4 antibodies, and their pathological conditions are similar. However, they have different levels of severity, and the detection sensitivity of their antibodies varies depending on the assay. Herein, we review three pathologies, namely, HIT, aHIT, and VITT, associated with anti-PF4 antibodies.

Intelligent Platelet Morphometry

Technological advances in image-based platelet analysis or platelet morphometry are critical for a better understanding of the structure and function of platelets in biological research as well as for the development of better clinical strategies in medical practice. Recently, the advent of high-throughput optical imaging and deep learning has boosted platelet morphometry to the next level by providing a new set of capabilities beyond what is achievable with traditional platelet morphometry, shedding light on the unexplored domain of platelet analysis. This Opinion article introduces emerging opportunities in 'intelligent' platelet morphometry, which are expected to pave the way for a new class of diagnostics, pharmacometrics, and therapeutics.

[Innovative activated platelet detection technology by artificial intelligence]

Although antiplatelet drugs are widely used for the prevention and treatment of atherothrombosis, clinical tests capable of evaluating their efficacy have not been established. Focusing on platelet aggregates in blood, we announced the world's first basic technology, an intelligent Image-Activated Cell Sorter (iIACS), that can exhaustively and rapidly identify cells one-by-one using image analysis with high-speed imaging and deep learning to sort specific cells according to the analysis results. This technology has even enabled the detection of single platelets with a size of 2 µm in blood samples and the quantification of the proportion of platelet aggregates by size. Furthermore, by applying this technique, we discovered different morphological features of platelet aggregates formed by different types of agonists that activate platelets. Here, we discuss this application in the early diagnosis of thrombotic microangiopathy (TMA). In the early stage of TMA, consumptive thrombocytopenia is caused by excessive platelet activation. Therefore, the detection of excessive platelet aggregates can lead to early TMA diagnosis.

Analysis of vasovagal syncope in the blood collection room in patients undergoing phlebotomy

Vasovagal syncope (VVS) is well-known to occur in patients undergoing phlebotomy, however, there have been no large-scale studies of the incidence of VVS in the blood collection room. The aim of our present retrospective study was to investigate the conditions of phlebotomy and determine the incidence/factors predisposing to the development of VVS. We investigated 677,956 phlebotomies performed in outpatients in the blood collection room, to explore factors predisposing to the development of VVS. Our analysis revealed an overall incidence of VVS of 0.004% and suggested that use of more than 5 blood collection tubes and a waiting time of more than 15 min were associated with a higher risk of VVS. The odds ratios of these factors were 8.10 (95% CI 3.76-17.50) and 3.69 (95% CI 0.87-15.60), respectively. This is the large-scale study to analyze factors of the development of VVS in the blood collection room, and according to our results, use of a large number of blood collection tubes and a prolonged waiting time for phlebotomy may be risk factors for the development of VVS.

Limitations of deuterium-labeled internal standards for quantitative electrospray ionization mass spectrometry analysis of fatty acid metabolites

RATIONALE

The electrospray ionization mass spectrometry (ESI-MS) methodology often shows poor ionization reproducibility in the analysis of biological samples. Therefore, normalization of the measured peak intensities is essential. It is believed that quantitative data with high reproducibility can be obtained by adding a constant amount of an internal standard (IS) material labeled with stable isotopes to each sample, thus allowing the correction of the quantitative value of the target compound by that of the IS. We investigated whether the presence or absence of a labeled IS improves the accuracy of these quantitative values.

METHODS

Triple quadrupole MS coupled with liquid chromatography was used to analyze fatty acid metabolites in biological samples as target compounds. Two independent systems were used to provide a measure of reproducibility in two different laboratories.

RESULTS

Data having poor reproducibility in the raw peak areas were efficiently normalized using the IS, but, crucially, the IS method using stable isotopes was not always necessary. In some cases, the reproducibility was relatively good even without using the IS. In a contaminant matrix, the MS response behavior of the target compound and its stable isotope-labeled material was complicated. Since ion suppression by matrix contaminants was dependent on the concentration of the target compound, the added amounts of the ISs were also important, Furthermore, an equivalent normalization effect was obtained by using a pooled quality control sample as an external standard, thus obviating the need for labeled IS samples, which are often expensive and sometimes not commercially available.

CONCLUSIONS

Our results raise the question as to whether the quantitative method using stable-isotope-labeled ISs is always necessary and beneficial. However, the results obtained in this study cannot be generalized because only fatty acid metabolites were examined using ESI-MS and only a highly substituted deuterium-labeled IS was used.

Intelligent classification of platelet aggregates by agonist type

Platelets are anucleate cells in blood whose principal function is to stop bleeding by forming aggregates for hemostatic reactions. In addition to their participation in physiological hemostasis, platelet aggregates are also involved in pathological thrombosis and play an important role in inflammation, atherosclerosis, and cancer metastasis. The aggregation of platelets is elicited by various agonists, but these platelet aggregates have long been considered indistinguishable and impossible to classify. Here we present an intelligent method for classifying them by agonist type. It is based on a convolutional neural network trained by high-throughput imaging flow cytometry of blood cells to identify and differentiate subtle yet appreciable morphological features of platelet aggregates activated by different types of agonists. The method is a powerful tool for studying the underlying mechanism of platelet aggregation and is expected to open a window on an entirely new class of clinical diagnostics, pharmacometrics, and therapeutics.

Platelets are small cells in the blood that primarily help stop bleeding after an injury by sticking together with other blood cells to form a clot that seals the broken blood vessel. Blood clots, however, can sometimes cause harm. For example, if a clot blocks the blood flow to the heart or the brain, it can result in a heart attack or stroke, respectively. Blood clots have also been linked to harmful inflammation and the spread of cancer, and there are now preliminary reports of remarkably high rates of clotting in COVID-19 patients in intensive care units.

A variety of chemicals can cause platelets to stick together. It has long been assumed that it would be impossible to tell apart the clots formed by different chemicals (which are also known as agonists). This is largely because these aggregates all look very similar under a microscope, making it incredibly time consuming for someone to look at enough microscopy images to reliably identify the subtle differences between them. However, finding a way to distinguish the different types of platelet aggregates could lead to better ways to diagnose or treat blood vessel-clogging diseases.

To make this possible, Zhou, Yasumoto et al. have developed a method called the “intelligent platelet aggregate classifier” or iPAC for short. First, numerous clot-causing chemicals were added to separate samples of platelets taken from healthy human blood. The method then involved using high-throughput techniques to take thousands of images of these samples. Then, a sophisticated computer algorithm called a deep learning model analyzed the resulting image dataset and “learned” to distinguish the chemical causes of the platelet aggregates based on subtle differences in their shapes. Finally, Zhou, Yasumoto et al. verified iPAC method’s accuracy using a new set of human platelet samples.

The iPAC method may help scientists studying the steps that lead to clot formation. It may also help clinicians distinguish which clot-causing chemical led to a patient’s heart attack or stroke. This could help them choose whether aspirin or another anti-platelet drug would be the best treatment. But first more studies are needed to confirm whether this method is a useful tool for drug selection or diagnosis.

Establishment of a megakaryoblastic cell line for conventional assessment of platelet calcium signaling

Platelet function tests utilizing agonists or patient serum are generally performed to assess platelet activation ex vivo. However, inter-individual differences in platelet reactivity and donor requirements make it difficult to standardize these tests. Here, we established a megakaryoblastic cell line for the conventional assessment of platelet activation. We first compared intracellular signaling pathways using CD32 crosslinking in several megakaryoblastic cell lines, including CMK, UT-7/TPO, and MEG-01 cells. We confirmed that CD32 was abundantly expressed on the cell surface, and that intracellular calcium mobilization and tyrosine phosphorylation occurred after CD32 crosslinking. We next employed GCaMP6s, a highly sensitive calcium indicator, to facilitate the detection of calcium mobilization by transducing CMK and MEG-01 cells with a plasmid harboring GCaMP6s under the control of the human elongation factor-1α promoter. Cells that stably expressed GCaMP6s emitted enhanced green fluorescent protein fluorescence in response to intracellular calcium mobilization following agonist stimulation in the absence of pretreatment. In summary, we have established megakaryoblastic cell lines that mimic platelets by mobilizing intracellular calcium in response to several agonists. These cell lines can potentially be utilized in high-throughput screening assays for the discovery of new antiplatelet drugs or diagnosis of disorders caused by platelet-activating substances.

Intelligent frequency-shifted optofluidic time-stretch quantitative phase imaging

Optofluidic time-stretch quantitative phase imaging (OTS-QPI) is a powerful tool as it enables high-throughput (>10,000 cell/s) QPI of single live cells. OTS-QPI is based on decoding temporally stretched spectral interferograms that carry the spatial profiles of cells flowing on a microfluidic chip. However, the utility of OTS-QPI is troubled by difficulties in phase retrieval from the high-frequency region of the temporal interferograms, such as phase-unwrapping errors, high instrumentation cost, and large data volume. To overcome these difficulties, we propose and experimentally demonstrate frequency-shifted OTS-QPI by bringing the phase information to the baseband region. Furthermore, to show its boosted utility, we use it to demonstrate image-based classification of leukemia cells with high accuracy over 96% and evaluation of drug-treated leukemia cells via deep learning.

The role of anti-complement factor H antibodies in the development of atypical haemolytic uremic syndrome: a possible contribution to abnormality of platelet function

Atypical haemolytic uremic syndrome (aHUS) is associated with complement system abnormality, such as production of complement factor H (CFH) autoantibodies. The growing evidence indicates complement overactivation on platelets is intimately involved in aHUS pathogenesis, besides endothelial injury. We here showed plasma from patients with anti-CFH antibodies induced aggregation of washed platelets, while purified anti-CFH antibodies suppressed aggregation. This suggested anti-CFH antibody itself suppressed thrombosis, while other plasma factor including complement factors could overactivate the platelets, leading to aggregation, which augmented the notion the state of complement activation influenced by anti-CFH antibodies is important in the aggregation of platelets in aHUS.

Author Correction: A practical guide to intelligent image-activated cell sorting

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Profiles of Coagulation and Fibrinolysis Activation-Associated Molecular Markers of Atypical Hemolytic Uremic Syndrome in the Acute Phase

Aim: Atypical hemolytic uremic syndrome (aHUS), characterized by thrombotic microangiopathy (TMA), is a genetic, life-threatening disease which needs many differential diagnoses. This study aimed to reveal coagulation and fibrinolysis profiles in aHUS and secondary TMA patients. Furthermore, we investigated whether aHUS patients progress to, and meet, disseminated intravascular coagulation (DIC) criteria.

Methods: The acute phase samples were available in 15 aHUS and 20 secondary TMA patients. We measured PT-ratio, activated partial thromboplastin time (APTT), fibrinogen, fibrin degradation product (FDP), fibrin monomer complex (FMC), antithrombin (AT), plasmin-α2 plasmin inhibitor complex (PIC), and von Willebrand factor antigen (VWF:Ag). We examined and compared these tests among aHUS, secondary TMA patients, and healthy volunteer (HV), and evaluated whether patients with aHUS and secondary TMA met DIC criteria.

Results: PT-ratio, APTT, FDP, FMC and PIC in patients with aHUS and secondary TMA were higher than those in HV. Fibrinogen and AT showed no significant difference among three groups. VWF:Ag was higher in only aHUS patients. No tests showed significant difference between aHUS and secondary TMA patients. Three aHUS patients out of 15 met DIC criteria.

Conclusion: We revealed the profiles and distributions of coagulation and fibrinolysis tests of aHUS and secondary TMA patients. All tests were enhanced compared to HV; however, our results showed the no specificities in distinguishing aHUS from secondary TMA patients. We also clarified that some aHUS patients fulfilled DIC diagnostic criteria, indicating that DIC itself cannot be an exclusion criterion of aHUS.

Intelligent whole-blood imaging flow cytometry for simple, rapid, and cost-effective drug-susceptibility testing of leukemia

Drug susceptibility (also called chemosensitivity) is an important criterion for developing a therapeutic strategy for various cancer types such as breast cancer and leukemia. Recently, functional assays such as high-content screening together with genomic analysis have been shown to be effective for predicting drug susceptibility, but their clinical applicability is poor since they are time-consuming (several days long), labor-intensive, and costly. Here we present a highly simple, rapid, and cost-effective liquid biopsy for ex vivo drug-susceptibility testing of leukemia. The method is based on an extreme-throughput (>1 million cells per second), label-free, whole-blood imaging flow cytometer with a deep convolutional autoencoder, enabling image-based identification of the drug susceptibility of every single white blood cell in whole blood within 24 hours by simply flowing a drug-treated whole blood sample as little as 500 μL into the imaging flow cytometer without labeling. Our results show that the method accurately evaluates the drug susceptibility of white blood cells from untreated patients with acute lymphoblastic leukemia. Our method holds promise for affordable precision medicine.

A practical guide to intelligent image-activated cell sorting

Intelligent image-activated cell sorting (iIACS) is a machine-intelligence technology that performs real-time intelligent image-based sorting of single cells with high throughput. iIACS extends beyond the capabilities of fluorescence-activated cell sorting (FACS) from fluorescence intensity profiles of cells to multidimensional images, thereby enabling high-content sorting of cells or cell clusters with unique spatial chemical and morphological traits. Therefore, iIACS serves as an integral part of holistic single-cell analysis by enabling direct links between population-level analysis (flow cytometry), cell-level analysis (microscopy), and gene-level analysis (sequencing). Specifically, iIACS is based on a seamless integration of high-throughput cell microscopy (e.g., multicolor fluorescence imaging, bright-field imaging), cell focusing, cell sorting, and deep learning on a hybrid software-hardware data management infrastructure, enabling real-time automated operation for data acquisition, data processing, intelligent decision making, and actuation. Here, we provide a practical guide to iIACS that describes how to design, build, characterize, and use an iIACS machine. The guide includes the consideration of several important design parameters, such as throughput, sensitivity, dynamic range, image quality, sort purity, and sort yield; the development and integration of optical, microfluidic, electrical, computational, and mechanical components; and the characterization and practical usage of the integrated system. Assuming that all components are readily available, a team of several researchers experienced in optics, electronics, digital signal processing, microfluidics, mechatronics, and flow cytometry can complete this protocol in ~3 months.

Mean platelet volume and lymphocyte-to-monocyte ratio are associated with shorter progression-free survival in EGFR-mutant lung adenocarcinoma treated by EGFR tyrosine kinase inhibitor

Background

A growing body of evidence supports the role of platelets in cancer metastasis, escape from immune surveillance, and angiogenesis. Mean platelet volume (MPV), which reflects platelet turnover, is reported routinely as part of automated complete blood count. Accumulating evidence suggests that MPV is a useful biomarker in several diseases including cancer. However, its role in cancer patients receiving molecular targeted therapy has not been described in the literature.

Materials and methods

We retrospectively analysed the prognostic impact of MPV in advanced or recurrent EGFR mutant lung adenocarcinoma treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs). Lymphocyte-to-monocyte ratio (LMR) has been previously reported to be a poor prognostic factor in EGFR mutant non-small cell lung cancer and was also included as a covariate.

Results

Using the previously described Cutoff Finder algorithm, the cut-off points for MPV and LMR that best predicted progression free survival (PFS) of EGFR-TKI were determined as 10.3 and 2.8, respectively. The median PFS was 14.7 and 8.2 months in MPV low and high groups (p = 0.013, log-rank test). The median PFS was 13.5 and 6.2 months in LMR high and low groups (p < 0.001, log-rank test). MPV and LMR were independently distributed (chi square test) and the multivariate analysis using Cox’s proportional hazards regression model revealed that high MPV, low LMR, and pleural effusion were significant predictors for shorter PFS.

Conclusion

MPV and LMR, measured as part of routine complete blood count, can be utilized to predict the outcome of EGFR-TKI therapy with no additional costs. Our results suggest a mechanism of EGFR-TKI resistance which is associated with the functional status of the platelets.

Clinical effects of recombinant thrombomodulin and defibrotide on sinusoidal obstruction syndrome after allogeneic hematopoietic stem cell transplantation

Sinusoidal obstruction syndrome (SOS) is a lethal complication after hematopoietic stem cell transplantation (HSCT). Defibrotide (DF) is the only drug internationally recommended for SOS treatment in Western countries. Recombinant human soluble thrombomodulin (rhTM), which is promising for the treatment of patients with disseminated intravascular coagulation, is also reported to be potentially effective for SOS. To clarify the safety and efficacy of DF and rhTM, we conducted a retrospective survey of these agents in Japan. Data from 65 patients who underwent allogeneic HSCT and received DF (n  =  24) or rhTM (n  =  41) for SOS treatment were collected. The complete response rates for SOS on day 100 were 50% and 54% in the DF and rhTM groups, respectively. The 100-day overall survival rates were 50% in the DF group, and 48% in the rhTM group. Several severe hemorrhagic adverse events were observed in one patient in the DF group and five patients in the rhTM group. The main causes of death were SOS-related death, and no patient died of direct adverse events of DF or rhTM. Our results suggest that rhTM, as well as DF, can be effective as a novel treatment option for SOS.

The Development of Acute Systemic Multiple Thrombosis after Achieving Remission during Systemic Glucocorticoid Therapy for Acquired Hemophilia A

Acquired hemophilia A (AHA) is a hemorrhagic disorder. Whether or not severe thrombotic events can develop without the use of bypassing agents in AHA patients is unclear. An 80-year-old woman with AHA underwent immunosuppressive therapy with prednisolone at 1 mg/kg daily. After achieving remission, she suddenly developed multiple organ failure due to acute systemic thrombosis and died within a few hours of the diagnosis. Patients with AHA, especially those with risk factors for thrombosis, have a considerable risk of developing thrombosis during the recovery phase of factor VIII activity and should be carefully monitored by coagulation testing.

The impact of night-shift work on platelet function in healthy medical staff

Objectives:

Rotating shift work has been reported to increase the risk of cardiovascular diseases. Vascular endothelial dysfunction and platelet activation are among the leading causes of thrombus formation in patients with myocardial infarction or stroke. Endothelial function has been shown to be impaired immediately after night-shift work; however, it is not known whether platelets are also activated. The aim of this study was to investigate the acute impact of night-shift work on platelet function.

Methods:

This observational study included 11 healthy medical staff members (seven women, median age 32 years). We examined each subject's platelet aggregation rates and the serum concentrations of eicosanoid mediators after night-shift work and on day-shift work without preceding night-shift work (baseline).

Results:

Platelet aggregation did not differ from baseline levels after night-shift work. However, serum cyclooxygenase (COX)-metabolized eicosanoid mediators, particularly thromboxane (Tx) B₂ (a stable metabolite of TxA₂ and the most important marker of platelet activation), were significantly higher after the night-shift than at baseline (median 65.3 vs 180.4 ng/ml).

Conclusions:

Although platelet aggregation did not increase, there was an increase in serum COX-metabolized eicosanoid mediators such as TxB₂ in healthy medical staff after night-shift work. This platelet hypersensitivity may be one of the mechanisms underlying the significant association between night-shift work and adverse cardiovascular outcomes.

Optofluidic time-stretch quantitative phase microscopy

Innovations in optical microscopy have opened new windows onto scientific research, industrial quality control, and medical practice over the last few decades. One of such innovations is optofluidic time-stretch quantitative phase microscopy - an emerging method for high-throughput quantitative phase imaging that builds on the interference between temporally stretched signal and reference pulses by using dispersive properties of light in both spatial and temporal domains in an interferometric configuration on a microfluidic platform. It achieves the continuous acquisition of both intensity and phase images with a high throughput of more than 10,000 particles or cells per second by overcoming speed limitations that exist in conventional quantitative phase imaging methods. Applications enabled by such capabilities are versatile and include characterization of cancer cells and microalgal cultures. In this paper, we review the principles and applications of optofluidic time-stretch quantitative phase microscopy and discuss its future perspective.

Multiplex quantitative analysis of eicosanoid mediators in human plasma and serum: Possible introduction into clinical testing

Eicosanoid mediators play important roles in maintaining the physiological and pathophysiological homeostasis in the body. Their measurements, however, are rarely performed in clinical practice. In the present study, we analyzed 30 varieties of eicosanoid mediators that were detectable in human plasma and serum collected from healthy donors, using liquid chromatography-tandem mass spectrometry from the viewpoint of the clinical application of the multiplex quantitation of eicosanoid mediators. Wider variety of eicosanoid mediators were detected in serum (27 out of 30) than in plasma (14 out of 30), since the serum was thought to contain lipid mediators released from activated platelets. Larger inter-individual variations were observed in the plasma and serum eicosanoid levels. On the other hand, the concentrations of eicosanoids were not affected by the platelet count but were affected by the concentration of arachidonic acid (AA) within the reference interval (17.4-40.5×10¹⁰/L). When serum samples from patients with hematological disorders were analyzed, the concentrations of AA were positively correlated with the platelet count. When the patients underwent ASA therapy, a marked decrease in the concentrations of thromboxane B₂ (TXB₂) and 12-hydroxyl-heptadecatrienoic acid (12-HHT) was observed. Considering the availability of serum samples in clinical settings, the serum analysis of eicosanoids may be clinically useful.

[Serum ALP elevation early after treatment is a predictor for response in myeloma patients treated with bortezomib]

Several studies have shown the predictive value of elevated serum alkaline phosphatase (ALP) level in multiple myeloma (MM) patients treated with bortezomib (BTZ). We assessed the relationship between changes in ALP levels during treatment and response. Thirty patients treated with BTZ in our hospital were analyzed retrospectively. Of the patients analyzed, 12 were male, median age was 62 years (42-86), and 11 had a history of prior chemotherapy. Eighteen patients were treated with BTZ alone or in combination with dexamethasone, while the others were treated with a combination regimen employing an alkylating agent. Seven patients had undergone autologous stem cell transplantation following BTZ therapy. Ten of 28 patients showed ALP elevation of 25% or more from the baseline at 3 weeks, and 14 of the 28 had this finding at 6 weeks. Four of 5 patients who had achieved VGPR or more showed ALP elevation of 25% or more at 3 weeks, and all five had this finding by 6 weeks. No patient without ALP elevation achieved VGPR or a better response. ALP elevation exceeding 25% from the baseline by day 42 is significantly associated with a treatment response better than VGPR (p=0.019). In conclusion, ALP elevation during BTZ treatment is a valuable prognostic marker.

Prognosis of patients with core binding factor acute myeloid leukemia after first relapse

Core binding factor acute myeloid leukemia is known to have a favorable prognosis, however, there have been no detailed analyses on prognostic factors after first relapse. Using a nationwide database, we retrospectively analyzed core binding factor acute myeloid leukemia patients who relapsed after being treated with chemotherapy alone during their first complete remission. Of a total of 397 patients who were diagnosed with core binding factor acute myeloid leukemia, 208 experienced a first relapse, and analyses were performed in 139 patients for whom additional data were available. In the entire cohort, the overall survival rate after relapse was 48% at 3 years. By multivariate analysis, younger age at diagnosis, a longer interval before relapse, and inv(16) were shown to be independently associated with better survival after relapse. Although there was no significant difference in survival after relapse between patients who underwent allogeneic hematopoietic cell transplantation and those who did not in the overall series of relapsed patients, we found that transplantation significantly improved survival among patients who had t(8;21) (54% versus 26% at 3 years, P=0.002). In addition, among patients with t(8;21), those who had different cytogenetics at relapse had a significantly improved survival after transplantation, while those who had same cytogenetics did not. We showed that the prognosis differs significantly and optimal treatment strategies may vary between groups of patients with core binding factor acute myeloid leukemia with different cytogenetic profiles at relapse. These findings may help to guide therapeutic decisions after first relapse.

Overexpression of factor VII ameliorates bleeding diathesis of factor VIII-deficient mice with inhibitors

INTRODUCTION

Factor VIII (FVIII) treatment for hemophilia A has difficulties in correcting bleeding diathesis in the presence of inhibitors.

MATERIALS AND METHODS

An adeno-associated virus type 8 (AAV8) vector containing the factor VII (FVII) gene or the activated factor VII (FVIIa) gene was used to investigate the therapeutic effect of FVII or FVIIa overexpression in FVIII-deficient mice with inhibitors.

RESULTS

Following repeated human FVIII injection, FVIII-deficient mice developed anti-human FVIII antibodies that cross-reacted with mouse FVIII. High transgene expression of murine FVII or murine FVIIa was achieved using the AAV8 vector and resulted in increased blood FVII activity greater than 800% of normal murine FVII levels in vector-injected FVIII-deficient mice. Thromboelastography analysis showed significant improvements in clotting time, clot formation time, α angle, and mean clot firmness in AAV8 vector-injected FVIII-deficient mice with inhibitors. Overexpression of FVIIa ameliorated the bleeding phenotype of FVIII-deficient mice with inhibitors and significantly increased the survival rate after tail clipping. In addition, overexpression of FVII increased the survival rate of FVIII-deficient mice with inhibitors after tail clipping though it was not as efficient as FVIIa overexpression.

CONCLUSIONS

These data suggest that FVII overexpression is an alternative strategy for the treatment of hemophilia A with inhibitors.

Porcine model of hemophilia A

Hemophilia A is a common X chromosome-linked genetic bleeding disorder caused by abnormalities in the coagulation factor VIII gene (F8). Hemophilia A patients suffer from a bleeding diathesis, such as life-threatening bleeding in the brain and harmful bleeding in joints and muscles. Because it could potentially be cured by gene therapy, subhuman animal models have been sought. Current mouse hemophilia A models generated by gene targeting of the F8 have difficulties to extrapolate human disease due to differences in the coagulation and immune systems between mice and humans. Here, we generated a porcine model of hemophilia A by nuclear transfer cloning from F8-targeted fibroblasts. The hemophilia A pigs showed a severe bleeding tendency upon birth, similar to human severe hemophiliacs, but in contrast to hemophilia A mice which rarely bleed under standard breed conditions. Infusion of human factor VIII was effective in stopping bleeding and reducing the bleeding frequency of a hemophilia A piglet but was blocked by the inhibitor against human factor VIII. These data suggest that the hemophilia A pig is a severe hemophilia A animal model for studying not only hemophilia A gene therapy but also the next generation recombinant coagulation factors, such as recombinant factor VIII variants with a slower clearance rate.

Three cases of acute or fulminant hepatitis E caused by ingestion of pork meat and entrails in Hokkaido, Japan: Zoonotic food-borne transmission of hepatitis E virus and public health concerns

AIM

  In developed countries including Japan, the transmission route of indigenous hepatitis E virus (HEV) infection is obscure. Accordingly, public health implications of indigenous HEV infection have not been well addressed. The aim of this study was to clarify the route of transmission of a small outbreak of acute hepatitis E and assess the public health implications of indigenous zoonotic HEV transmission.

METHODS

  Three patients with non-A, B and C acute hepatitis, two of whom presented in a critical condition, were assessed for HEV infection using polymerase chain reaction and their route of infection; the genome sequences of the infecting HEV were also analyzed. A phylogenetic tree based on the full, or near full, HEV RNA sequences were constructed by neighbor-joining method.

RESULTS

  All three patients ingested grilled pork meat and entrails at the same barbecue restaurant in Abashiri, Hokkaido, Japan. When comparing partial to entire, or nearly entire, nucleotide sequences of HEV detected in these patients, they were 99.9-100% identical to each other. These genotype 4 isolates had great resemblance to the genome sequences of the isolates from the mini-outbreak in 2004 in Kitami, a city adjacent to Abashiri. These Kitami/Abashiri strains were segregated into a single cluster on the phylogenetic tree of HEV genotype 4 indigenous to Japan.

CONCLUSION

  Indigenous HEV transmission via a zoonotic food-borne route has been demonstrated in Kitami and Abashiri via pork meat and entrails contaminated with virulent HEV strains. Because a similar outbreak can recur in the future, infection sources and distribution routes should be clarified rapidly for public health.

Intra-articular injection of mesenchymal stem cells expressing coagulation factor ameliorates hemophilic arthropathy in factor VIII-deficient mice

BACKGROUND

Transplantation of cells overexpressing a target protein represents a viable gene therapeutic approach for treating hemophilia. Here, we focused on the use of autologous mesenchymal stem cells (MSCs) expressing coagulation factor for the treatment of coagulation factor VIII (FVIII) deficiency in mice.

METHODS AND RESULTS

Analysis of luciferase gene constructs driven by different promoters revealed that the plasminogen activator inhibitor-1 (PAI-1) gene promoter coupled with the cytomegalovirus promoter enhancer region was one of the most effective promoters for producing the target protein. MSCs transduced with the simian immunodeficiency virus (SIV) vector containing the FVIII gene driven by the PAI-1 promoter expressed FVIII for several months, and this expression was maintained after multiple mesenchymal lineage differentiation. Although intravenous injection of cell supernatant derived from MSCs transduced with an SIV vector containing the FVIII gene driven by the PAI-1 promoter significantly increased plasma FVIII levels, subcutaneous implantation of the MSCs resulted in a transient and weak increase in plasma FVIII levels in FVIII-deficient mice. Interestingly, intra-articular injection of the transduced MSCs significantly ameliorated the hemarthrosis and hemophilic arthropathy induced by knee joint needle puncture in FVIII-deficient mice. The therapeutic effects of a single intra-articular injection of transduced MSCs to inhibit joint bleeding persisted for at least 8 weeks after administration.

CONCLUSIONS

MSCs provide a promising autologous cell source for the production of coagulation factor. Intra-articular injection of MSCs expressing coagulation factor may offer an attractive treatment approach for hemophilic arthropathy.

Mutant macaque factor IX T262A: a tool for hemophilia B gene therapy studies in macaques

INTRODUCTION

Gene therapy is expected to be the next generation therapy for hemophilia, and a good animal model is required for hemophilia gene therapy preclinical studies.

METHODS

Taking advantage of the human factor IX (FIX) specificity of monoclonal antibody 3A6, the epitope of which resides in the amino acid polypeptide segment including Ala 262 of human FIX, mutant macaque FIX with an amino acid substitution of Thr 262 to Ala (macaque FIX T262A) was generated and its reactivity to monoclonal antibody 3A6, biological activity and expression in vivo were studied.

RESULTS

Enzyme-linked immunosorbent assays (ELISAs) and Western blot analyses showed that monoclonal antibody 3A6 bound to human FIX and macaque FIX T262A but not to wild-type macaque FIX. Recombinant macaque FIX T262A exhibited a comparable coagulation activity to wild-type macaque FIX and human FIX. High expression of macaque FIX T262A was achieved in mice by injection of AAV8 vectors carrying the macaque FIX T262A gene and reached levels of up to 31.5microg/mL (1050% of the normal human FIX concentration). Macaque FIX T262A expressed in the liver of mice was as biologically active as that expressed in vitro. In addition, the macaque FIX T262A concentrations determined by a 3A6-based ELISA were not influenced by the presence of normal macaque plasma.

CONCLUSIONS

The results of the present study suggest that macaque FIX T262A may be processed appropriately in vivo and that the macaque FIX T262A concentration in the macaque circulation can be quantified precisely by a monoclonal antibody 3A6-based ELISA.

Successful treatment of acute myelogenous leukemia with favorable cytogenetics by reduced-intensity stem cell transplantation

Acute myelogenous leukemia (AML) with favorable cytogenetics responds well to chemotherapy. If the leukemia relapses, allogenic hematopoietic stem transplantation (allo-HSCT) is considered as a treatment option. Since the efficacy of reduced-intensity stem cell transplantation (RIST) for AML with favorable cytogenetics has not been established, we retrospectively analyzed the outcomes of allo-HSCT in AML patients according to cytogenetic risks. The outcome of allo-HSCT for AML patients with favorable cytogenetics seemed to be superior to that for AML patients with intermediate cytogenetics. In AML patients with favorable cytogenetics, the 3-year overall survival (OS) and relapse-free survival (RFS) rates were 88 and 76%, respectively, in the RIST group. Both the 3-year OS and RFS rates were 81% in the conventional stem cell transplantation (CST) group. The outcome of RIST for AML patients with favorable cytogenetics was comparable to that for patients who received CST despite the more advanced age and greater organ dysfunction in RIST group than in CST group. None of the patients died within 90 days after RIST. Moreover, there was no relapse in patients with favorable cytogenetics who were in hematological remission prior to RIST. Thus, RIST for AML patients with favorable cytogenetics in remission is safe and effective.

Increased number of CD16(+)CD56(dim) NK cells in peripheral blood mononuclear cells after allogeneic cord blood transplantation

In the present study, we investigated subpopulations of natural killer (NK) cells and the expression of stimulatory and inhibitory NK receptors after adult blood and bone marrow transplantation (BBMT) and cord blood transplantation (CBT). There were significant increases in CD16(+)CD56(dim) cell proportion and in absolute number in peripheral blood mononuclear cells (PBMC) during a period of 4-9 months after CBT compared with these in normal PBMC, cord blood (CB), and in PBMC after BBMT. Also, increased numbers of CD16(+)CD56(dim) NK cells were sustained in some patients until 4 years after CBT. This CD16(+)CD56(dim) cell subset after CBT exhibited decreased expression of NKG2A compared with that in CB and increased expression of NKG2C. Purified CD16(+)CD56(dim) cells from patients 8-9 months after CBT exhibited significantly higher levels of cytolytic activity against K562 than did purified CD16(+)CD56(bright) cells and also whole PBMC. The CD16(+)CD56(dim) cell subset with a high level of cytolytic activity significantly increased after CBT, and these cells may be responsible for NK cell-mediated immunity after CBT.