Platelet lifespan and mechanisms for clearance

PURPOSE OF REVIEW

Activated or aged platelets are removed from circulation under (patho)physiologic conditions, the exact mechanism of platelet clearance under such conditions remains unclear and are currently being investigated. This review focuses on recent findings and controversies regarding platelet clearance and the disruption of platelet life cycle.

RECENT FINDINGS

The platelet life span is determined by glycosylation of platelet surface receptors with sialic acid. Recently, it was shown that platelet activation and granule release leads to desialylation of glycans and accelerated clearance of platelets under pathological conditions. This phenomenon was demonstrated to be a main reason for thrombocytopenia being a complication in several infections and immune disorders.

SUMMARY

Although we have recently gained some insight into how aged platelets are cleared from circulation, we are still not seeing the full picture. Further investigations of the platelet clearance pathways under pathophysiologic conditions are needed as well as studies to unravel the connection between platelet clearance and platelet production.

Right heart thrombus-in-transit in a patient with Evans syndrome: A case report

INTRODUCTION

Right heart free-floating thrombus in the absence of structural heart disease or atrial fibrillation is rare. When it travels to the heart into the lung, called thrombus-in-transit, may cause cardiopulmonary collapse and sudden death. The clinical presentation varies from mild respiratory symptoms to sudden death; however, there are few clinical case reports of giant, free-floating thrombus in the right heart in an asymptomatic patient, and the optimal management options have not been established.

PATIENT CONCERNS

A 36-year-old Asian woman presented to the emergency department with complaints of worsening swelling of the left lower extremity over 12 hours.

DIAGNOSIS

Left leg deep vein thrombosis accompanied by an asymptomatic giant right atrial thrombus and pulmonary embolism with a rare autoimmune disease of Evans syndrome.

INTERVENTIONS

Emergent surgical thrombectomy under cardiopulmonary bypass for right atrial thrombus.

OUTCOMES

The postoperative course was uneventful, and she was discharged on the eighth postoperative day with normal heart function and mild tricuspid regurgitation.

CONCLUSION

An additional diagnostic workup in cases of deep vein thrombosis is necessary for the rapid diagnosis of right heart thrombus and pulmonary embolism without delay. This case report illustrates that early recognition of venous thromboembolism and emergent thrombectomy of right heart thrombus-in-transit is crucial to prevent mortality.

Vaccine-induced thrombotic thrombocytopenia: the elusive link between thrombosis and adenovirus-based SARS-CoV-2 vaccines

The amazing effort of vaccination against COVID-19, with more than 2 billion vaccine doses administered all around the world as of 16 June 2021, has changed the history of this pandemic, drastically reducing the number of severe cases or deaths in countries were mass vaccination campaign have been carried out. However, the people's rising enthusiasm has been blunted in late February 2021 by the report of several cases of unusual thrombotic events in combination with thrombocytopenia after vaccination with ChAdOx1 nCov-19 (Vaxzevria), and a few months later also after Ad26.COV2. S vaccines. Of note, both products used an Adenovirus-based (AdV) platform to deliver the mRNA molecule - coding for the spike protein of SARS-CoV-2. A clinical entity characterized by cerebral and/or splanchnic vein thrombosis, often associated with multiple thromboses, with thrombocytopenia and bleeding, and sometimes disseminated intravascular coagulation (DIC), was soon recognized as a new syndrome, named vaccine-induced immune thrombotic thrombocytopenia (VITT) or thrombosis with thrombocytopenia syndrome (TTS). VITT was mainly observed in females under 55 years of age, between 4 and 16 days after receiving only Adenovirus-based vaccine and displayed a seriously high fatality rate. This prompted the Medicine Regulatory Agencies of various countries to enforce the pharmacovigilance programs, and to provide some advices to restrict the use of AdV-based vaccines to some age groups. This point-of view is aimed at providing a comprehensive review of epidemiological issues, pathogenetic hypothesis and treatment strategies of this rare but compelling syndrome, thus helping physicians to offer an up-to dated and evidence-based counseling to their often alarmed patients.

Heparin induced thrombocytopenia: position paper from the Italian Society on Thrombosis and Haemostasis (SISET)

Heparin induced thrombocytopenia (HIT) is a rare immune mediated adverse drug reaction occurring after exposure to heparin. It is a serious and potentially fatal condition, which may be associated with the development of arterial or venous thrombotic events. Although known for many years, HIT is still often misdiagnosed. Pre- test clinical probability, screening for anti-PF4/heparin antibodies and documentation of their platelet activating capacity are the cornerstones of diagnosis. However, both clinical algorithms and test modalities have limited predictive values and limited diffusion so that the diagnosis and management is challenging in the clinical practice. For this reason, there is an unmet need for novel rational non-anticoagulant therapies based on the pathogenesis of HIT.The present paper reports the position of the Italian Society on Haemostasis and Thrombosis (SISET) in order to increase awareness of HIT among clinicians and other health care professionals and to provide information on the most appropriate management.

Pathogenesis of heparin-induced thrombocytopenia

There are currently no effective substitutes for high intensity therapy with unfractionated heparin (UFH) for cardiovascular procedures based on its rapid onset of action, ease of monitoring and reversibility. The continued use of UFH in these and other settings requires vigilance for its most serious nonhemorrhagic complication, heparin induced thrombocytopenia (HIT). HIT is an immune prothrombotic disorder caused by antibodies that recognize complexes between platelet factor 4 (PF4) and polyanions such as heparin (H).The pathogenicity of anti-PF4/H antibodies is likely due to the formation of immune complexes that initiate intense procoagulant responses by vascular and hematopoietic cells that lead to the generation of platelet microparticles, monocyte and endothelial cell procoagulant activity, and neutrophil extracellular traps, among other outcomes. The development of anti-PF4/H antibodies after exposure to UFH greatly exceeds the incidence of clinical disease, but the biochemical features that distinguish pathogenic from nonpathogenic antibodies have not been identified. Diagnosis relies on pretest clinical probability, screening for anti-PF4/H antibodies and documentation of their platelet activating capacity. However, both clinical algorithms and test modalities have limited predictive values making diagnosis and management challenging. Given the unacceptable rates of recurrent thromboembolism and bleeding associated with current therapies, there is an unmet need for novel rational nonanticoagulant therapeutics based on the pathogenesis of HIT. We will review recent developments in our understanding of the pathogenesis of HIT and its implications for future approaches to diagnosis and management.

Pre-eclampsia-like syndrome induced by severe COVID-19: a prospective observational study

OBJECTIVES

To investigate the incidence of clinical, ultrasonographic and biochemical findings related to pre-eclampsia (PE) in pregnancies with COVID-19, and to assess their accuracy to differentiate between PE and the PE-like features associated with COVID-19.

DESIGN

A prospective, observational study.

SETTING

Tertiary referral hospital.

PARTICIPANTS

Singleton pregnancies with COVID-19 at >20+0  weeks.

METHODS

Forty-two consecutive pregnancies were recruited and classified into two groups: severe and non-severe COVID-19, according to the occurrence of severe pneumonia. Uterine artery pulsatility index (UtAPI) and angiogenic factors (soluble fms-like tyrosine kinase-1/placental growth factor [sFlt-1/PlGF]) were assessed in women with suspected PE.

MAIN OUTCOME MEASURES

Incidence of signs and symptoms related to PE, such as hypertension, proteinuria, thrombocytopenia, elevated liver enzymes, abnormal UtAPI and increased sFlt-1/PlGF.

RESULTS

Thirty-four cases were classified as non-severe and 8 as severe COVID-19. Five (11.9%) women presented signs and symptoms of PE, all five being among the severe COVID-19 cases (62.5%). However, abnormal sFlt-1/PlGF and UtAPI could only be demonstrated in one case. One case remained pregnant after recovery from severe pneumonia and had a spontaneous resolution of the PE-like syndrome.

CONCLUSIONS

Pregnant women with severe COVID-19 can develop a PE-like syndrome that might be distinguished from actual PE by sFlt-1/PlGF, LDH and UtAPI assessment. Healthcare providers should be aware of its existence and monitor pregnancies with suspected pre-eclampsia with caution.

TWEETABLE ABSTRACT

This study shows that a pre-eclampsia-like syndrome could be present in some pregnancies with severe COVID-19.

Coronavirus disease 2019 (COVID-19) related cytopenia: A protocol for systematic review and meta-analysis

BACKGROUND

In December 2019, the novel coronavirus pneumonia was detected in Wuhan and named COVID-19. It is an international outbreak of the respiratory illness caused by severe acute respiratory syndrome coronavirus 2. Recent papers pointed out the cytopenia in COVID-19 patients including lymphopenia, neutrophilia, thrombocytopenia and lower level of hemoglobin had prognostic significance. This systemic review and meta-analysis summaries the latest evidence from available data and determine the hematological abnormality caused by severe acute respiratory syndrome coronavirus 2 and potential efficacy on the outcomes in patients with COVID-19.

METHODS

This protocol for a systematic reviews and meta-analysis will be performed according to the preferred reporting items for systematic reviews and meta-analysis protocols 2015 guidelines. The database of Cochrane Library, PUBMED, EMBASE, Medline, Web of Science, Google Scholar, CNKI, WanFang, as well as gray literatures from the inception to present will be comprehensively and systematically searched without limitations of regions or language. The main study outcomes will be the mortality of COVID-19 patients. The meta-analysis was performed by RevMan V.5.3 program and Stata V.12.0 software after 2 reviewers independently selected literature, data extraction, bias risk evaluation and study quality assessment. Any disagreement will be resolved by consensus to the third researcher.

RESULTS

This systematic review and meta-analysis may help provide clarify on the effect of cytopenia in patients with COVID-19. The result will be published at a peer-reviewed journal.

CONCLUSIONS

This proposed study will evaluate the existing evidence on the effectiveness of cytopenia in COVID-19 patients.

ETHIC AND DISSEMINATION

The content of this article does not involve moral approval or ethical review because no individual data will be collected.

PROSPERO REGISTRATION

CRD42020187524.

Laparoscopic splenic artery ligation in a patient with immune thrombocytopenia with intracranial haemorrhage (two clips that stopped a timebomb)

Intracranial haemorrhage (ICH) in a patient with relapse of idiopathic thrombocytopaenic purpura (ITP) can be lethal. The site of haemorrhage, compounded by low platelets in this disease, makes its management extremely challenging, especially when a neurosurgical procedure is warranted. We report a case report of an unconventional way of increasing platelet counts in ITP rapidly in an emergency setting.

Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures

By 27 February 2020, the outbreak of coronavirus disease 2019 (COVID-19) caused 82 623 confirmed cases and 2858 deaths globally, more than severe acute respiratory syndrome (SARS) (8273 cases, 775 deaths) and Middle East respiratory syndrome (MERS) (1139 cases, 431 deaths) caused in 2003 and 2013, respectively. COVID-19 has spread to 46 countries internationally. Total fatality rate of COVID-19 is estimated at 3.46% by far based on published data from the Chinese Center for Disease Control and Prevention (China CDC). Average incubation period of COVID-19 is around 6.4 days, ranges from 0 to 24 days. The basic reproductive number (R₀ ) of COVID-19 ranges from 2 to 3.5 at the early phase regardless of different prediction models, which is higher than SARS and MERS. A study from China CDC showed majority of patients (80.9%) were considered asymptomatic or mild pneumonia but released large amounts of viruses at the early phase of infection, which posed enormous challenges for containing the spread of COVID-19. Nosocomial transmission was another severe problem. A total of 3019 health workers were infected by 12 February 2020, which accounted for 3.83% of total number of infections, and extremely burdened the health system, especially in Wuhan. Limited epidemiological and clinical data suggest that the disease spectrum of COVID-19 may differ from SARS or MERS. We summarize latest literatures on genetic, epidemiological, and clinical features of COVID-19 in comparison to SARS and MERS and emphasize special measures on diagnosis and potential interventions. This review will improve our understanding of the unique features of COVID-19 and enhance our control measures in the future.

Association of Bleeding Scores and Platelet Transfusions With Platelet Counts and Closure Times in Response to Adenosine Diphosphate (CT-ADPs) Among Preterm Neonates With Thrombocytopenia

This cohort study analyzes the association of closure time in response to adenosine diphosphate (CT-ADP) with bleeding score and the associations of platelet transfusions with change in platelet count, CT-ADP, and bleeding scores in preterm neonates with thrombocytopenia.

Analysis of the laboratory indexes and risk factors in 189 cases of severe fever with thrombocytopenia syndrome

The current study aimed to analyze the clinical characteristics of severe fever with thrombocytopenia syndrome (SFTS) and to explore the risk factors of critical patients. From 2016 to 2018, we collected the hospitalized diagnosed cases with SFTS in Jinan infectious disease hospital of Shandong University and analyzed by the descriptive epidemiological method. According to the prognosis, they were divided into general group and severe group. The epidemiological characteristics, clinical features, and laboratory indexes of these 2 groups of patients were compared and analyzed at the first visit. The risk factors related to the severity of the disease were analyzed by univariate Logistic regression. In total, 189 cases of SFTS were treated during the period and 33 deaths occurred in the severe group, with the fatality rate of 17.46%. The patients' age (χ = 8.864, P < .01), ALT (Z = -2.304, P = .03), AST (Z = -3.361, P < .01), GLU (t = -4.115, P < .01), CK (Z = -3.964, P < .01), CK-MB (Z = -2.225, P = .03), LDH (Z = -3.655, P < .01), α-HBDH (Z = -2.040, P = .04), APTT (t = -3.355, P < .01), BUN (Z = -2.040, P = .04), Cr (Z = -3.071, P = .01), and D-dimer (Z = -2.026, P = .04) in the severe group were higher than that in the normal group, but the blood platelet (PLT) counts were significantly lower (Z = -2.778, P < .01) than that in the normal group. With the neuropsychiatric symptoms (OR = 24.083, 95% CI = 6.064-95.642), skin bleeding point (OR = 30.000, 95% CI = 6.936-129.764), multiple organ dysfunction (OR = 34.048, 95% CI = 7.740-149.782), past medical history (OR = 3.792, 95% CI = 1.284-11.200), and fasting glucose elevation (OR = 1.359, 95% CI = 1.106-1.668) could predict the severity of the SFTS. In summary, the abnormality of the laboratory index, the special clinical manifestations, and the past medical history of SFTS patients were the important basis for judging the patient's serious condition.

Cirrhosis in Wilson Disease is characterized by Impaired Hepatic Synthesis, Leukopenia and Thrombocytopenia

Background: Patients with Wilson disease (WD) progress to cirrhosis at an early age but have good prognoses. This study aimed to delineate hepatic features in WD patients with or without cirrhosis. Methods: Medical data were retrospectively collected from 27 July 2015 to 27 June 2018. WD patients were divided into two groups based on whether or not they progressed to cirrhosis. Liver function, portal hypertension features and hematocytopenia rates were compared between groups. Results: The study enrolled 119 WD patients with cirrhosis and 53 WD patients without cirrhosis. There were no differences between groups for liver enzyme levels or incidence rates of Kayser-Fleischer ring (all P > 0.05). Ascites and hepatic encephalopathy were nearly absent in both groups, and almost all patients were Child-Pugh group A. However, WD-associated cirrhotic patients had a higher prothrombin time (beta = 0.908, P = 0.004) and international normalized ratio (beta = 0.089, P = 0.040), wider portal vein diameter (beta = 1.330, P < 0.001), and an increased risk of splenomegaly/splenectomy (odds ratio [OR] = 4.36, 95% confidence interval [CI]: 2.15-8.84, P < 0.001). Moreover, WD-associated cirrhotic patients have significantly increased risks of leukopenia (OR = 2.30, 95% CI: 1.00-5.25, P = 0.049) and thrombocytopenia (OR = 6.89, 95% CI: 2.01-23.59, P = 0.002). Conclusions: Despite presenting good outcomes, mild hepatocyte injury, and good hepatic metabolic function, WD-associated cirrhotic patients show more serious impairment of hepatic synthetic function, wider portal vein diameter, and higher risk of splenomegaly due to portal hypertension.

Epidemiology and prognostic factors of nosocomial candidemia in Northeast Brazil: A six-year retrospective study

Candidemia has been considered a persistent public health problem with great impact on hospital costs and high mortality. We aimed to evaluate the epidemiology and prognostic factors of candidemia in a tertiary hospital in Northeast Brazil from January 2011 to December 2016. Demographic and clinical data of patients were retrospectively obtained from medical records and antifungal susceptibility profiling was performed using the broth microdilution method. A total of 68 episodes of candidemia were evaluated. We found an average incidence of 2.23 episodes /1000 admissions and a 30-day mortality rate of 55.9%. The most prevalent species were Candida albicans (35.3%), Candida tropicalis (27.4%), Candida parapsilosis (21.6%) and Candida glabrata (11.8%). Higher mortality rates were observed in cases of candidemia due to C. albicans (61.1%) and C. glabrata (100%), especially when compared to C. parapsilosis (27.3%). Univariate analysis revealed some variables which significantly increased the probability of death: older age (P = 0.022; odds ratio [OR] = 1.041), severe sepsis (P < 0.001; OR = 8.571), septic shock (P = 0.035; OR = 3.792), hypotension (P = 0.003; OR = 9.120), neutrophilia (P = 0.046; OR = 3.080), thrombocytopenia (P = 0.002; OR = 6.800), mechanical ventilation (P = 0.009; OR = 8.167) and greater number of surgeries (P = 0.037; OR = 1.920). Multivariate analysis showed that older age (P = 0.040; OR = 1.055), severe sepsis (P = 0.009; OR = 9.872) and hypotension (P = 0.031; OR = 21.042) were independently associated with worse prognosis. There was no resistance to amphotericin B, micafungin or itraconazole and a low rate of resistance to fluconazole (5.1%). However, 20.5% of the Candida isolates were susceptible dose-dependent (SDD) to fluconazole and 7.7% to itraconazole. In conclusion, our results could assist in the adoption of strategies to stratify patients at higher risk for developing candidemia and worse prognosis, in addition to improve antifungal management.

Response of an oscillatory differential delay equation to a periodic stimulus

Periodic hematological diseases such as cyclical neutropenia or cyclical thrombocytopenia, with their characteristic oscillations of circulating neutrophils or platelets, may pose grave problems for patients. Likewise, periodically administered chemotherapy has the unintended side effect of establishing periodic fluctuations in circulating white cells, red cell precursors and/or platelets. These fluctuations, either spontaneous or induced, often have serious consequences for the patient (e.g. neutropenia, anemia, or thrombocytopenia respectively) which exogenously administered cytokines can partially correct. The question of when and how to administer these drugs is a difficult one for clinicians and not easily answered. In this paper we use a simple model consisting of a delay differential equation with a piecewise linear nonlinearity, that has a periodic solution, to model the effect of a periodic disease or periodic chemotherapy. We then examine the response of this toy model to both single and periodic perturbations, meant to mimic the drug administration, as a function of the drug dose and the duration and frequency of its administration to best determine how to avoid side effects.

Platelet activation and prothrombotic properties in a mouse model of peritoneal sepsis

Sepsis is associated with thrombocytopenia and microvascular thrombosis. Studies have described platelets implication in this pathology but their kinetics of activation and behavior remain poorly known. We show in a mouse model of peritonitis, the appearance of platelet-rich thrombi in organ microvessels and organ damage. Complementary methods are necessary to characterize platelet activation during sepsis as circulating soluble markers and platelet-monocyte aggregates revealed early platelet activation, while surface activation markers were detected at later stage. A microfluidic based ex-vivo thrombosis assay demonstrated that platelets from septic mice have a prothrombotic behavior at shear rate encountered in microvessels. Interestingly, we found that even though phosphoinositide-3-kinase β-deficient platelet mice formed less thrombi in liver microcirculation, peritoneal sepsis activates a platelet alternative pathway to compensate the otherwise mandatory role of this lipid-kinase to form stable thrombi at high shear rate. Platelets are rapidly activated during sepsis. Thrombocytopenia can be attributed in part to platelet-rich thrombi formation in capillaries and platelet-leukocytes interactions. Platelets from septic mice have a prothrombotic phenotype at a shear rate encountered in arterioles. Further studies are necessary to unravel molecular mechanisms leading to this prothrombotic state of platelets in order to guide the development of future treatments of polymicrobial sepsis.

Thrombocytopenia in leukemia: Pathogenesis and prognosis

Leukemias, a heterogeneous group of hematological disorders, are characterized by ineffective hematopoiesis and morphologic abnormalities of hematopoietic cells. Thrombocytopenia is a common problem among leukemia types that can lead to hemorrhagic complications in patients. The purpose of this review article is to identify the conditions associated with the incidence of thrombocytopenia in leukemias. It can be stated that although translocations have been considered responsible for this complication in many studies, other factors such as bone marrow failure, genes polymorphism, a mutation in some transcription factors, and the adverse effects of treatment could be associated with pathogenesis and poor prognosis of thrombocytopenia in leukemias. Considering the importance of thrombocytopenia in leukemias, it is hoped that the recognition of risk factors increasing the incidence of this complication in leukemic patients would be useful for prevention and treatment of this disorder.

Fragmentation of Red Blood Cells Caused Pseudothrombocytosis in a Patient

BACKGROUND

Pseudothrombocytopenia, caused by platelet (PLT) clumping, is often found in clinical studies [1]. However, pseudothrombocytosis resulting from the fragmentation of red blood cells (RBCs) is a very rare phenomenon.

METHODS

EDTA-K2 anticoagulation was used on a sample of venous blood extracted from the patient. A Symex XN9000 automatic blood analyzer was used to conduct CBC + DIFF mode and CBC + DIFF + RET mode tests, stained smear microscopy.

RESULTS

The Symex XN9000 automatic blood analyzer was used to conduct CBC + DIFF mode test; PLTs were measured at 570 x 109/L. Stained smear microscopy revealed the number of PLTs did not conform to the instrument measured 570 x 109/L. "RET" alarm instrument, switch to CBC + DIFF + RET mode for testing. The second test result showed PLTs at 128 x 109/L, which accords with artificial microscopy.

CONCLUSIONS

This was a case of a very rare phenomenon: the fragmentation of RBCs caused pseudothrombocytosis.

Thrombocytopenia after liver transplantation: Should we care?

Transient thrombocytopenia is a common phenomenon after liver transplantation. After liver transplantation (LT), platelet count decreases and reaches a nadir on postoperative days 3-5, with an average reduction in platelet counts of 60%; platelet count recovers to preoperative levels approximately two weeks after LT. The putative mechanisms include haemodilution, decreased platelet production, increased sequestration, medications, infections, thrombosis, or combination of these processes. However, the precise mechanisms remain unclear. The role of platelets in liver transplantation has been highlighted in recent years, and particular attention has been given to their effects beyond hemostasis and thrombosis. Previous studies have demonstrated that perioperative thrombocytopenia causes poor graft regeneration, increases the incidence of postoperative morbidity, and deteriorates the graft and decreases patient survival in both the short and long term after liver transplantation. Platelet therapies to increase perioperative platelet counts, such as thrombopoietin, thrombopoietin receptor agonist, platelet transfusion, splenectomy, and intravenous immunoglobulin treatment might have a potential for improving graft survival, however clinical trials are lacking. Further studies are warranted to detect direct evidence on whether thrombocytopenia is the cause or result of poor-graft function and postoperative complications, and to determine who needs platelet therapies in order to prevent postoperative complications and thus improve post-transplant outcomes.

A novel heterozygous ITGB3 p.T720del inducing spontaneous activation of integrin αIIbβ3 in autosomal dominant macrothrombocytopenia with aggregation dysfunction

We identified a novel heterozygous ITGB3 p.T720del mutation in a pedigree with macrothrombocytopenia exhibiting aggregation dysfunction. Platelet aggregation induced by ADP and collagen was significantly reduced, while ristocetin aggregation was normal. Integrin αIIbβ3 was partially activated in a resting status, but platelet expression of αIIbβ3 was downregulated. Functional analysis using a cell line showed spontaneous phosphorylation of FAK in αIIb/β3 (p.T720del)-transfected 293T cells in suspension conditions. Abnormal cytoplasmic protrusions, membrane ruffling, and cytoplasmic localization of αIIbβ3 were observed in αIIb/β3 (p.T720del)-transfected CHO cells. Such morphological changes were reversed by treatment with an FAK inhibitor. These findings imply spontaneous, but partial, activation of αIIbβ3 followed by phosphorylation of FAK as the initial mechanism of abnormal thrombopoiesis. Internalization and decreased surface expression of αIIbβ3 would contribute to aggregation dysfunction. We reviewed the literature of congenital macrothrombocytopenia associated with heterozygous ITGA2B or ITGB3 mutations. Reported mutations were highly clustered at the membrane proximal region of αIIbβ3, which affected the critical interaction between αIIb R995 and β3 D723, resulting in a constitutionally active form of the αIIbβ3 complex. Macrothrombocytopenia caused by a heterozygous activating mutation of ITGA2B or ITGB3 at the membrane proximal region forms a distinct entity of rare congenital thrombocytopenia.

Thrombopénie sévère chez un nouveau né de mère splénectomisé pour purpura thrombopénique idiopathique

Neonatal thrombopenia is the most common hemostatic abnormality in newborns. It is defined as a platelet count below 150.000/mm3. 40% of newborns to mothers with a history of autoimmune thrombopenia are at risk of developing neonatal thrombopenia while 10-15% of them are at risk of developing severe thrombopenia. We here report the case of a 20 days old newborn to mother splenectomized for idiopathic thrombopenic purpura in order to highlight the relationship between the severity of maternal disease and the severity of the neonatal thrombopenia and thereby to avoid the risk of intracranial hemorrhage resulting in death or neurological sequelae.

Lung as a Niche for Hematopoietic Progenitors

Platelets are released from megakaryocytes. The bone marrow has been proposed to be the major site where this process occurs. Lefrançais et al. (2017) using state-of-the-art techniques including two-photon microscopy, in vivo lineage-tracing technologies, and sophisticated lung transplants reveal that the lung is also a primary site for platelet biogenesis. Strikingly, lung megakaryocytes can completely reconstitute platelet counts in the blood in mice with thrombocytopenia. This study also shows that hematopoietic progenitors, with capacity to repopulate the bone marrow after irradiation, are present in the lungs. This work brings a novel unexpected role for the lung as a niche for hematopoiesis. The emerging knowledge from this research may be important for the treatment of several disorders.

Successful eltrombopag treatment of severe refractory thrombocytopenia in chronic myelomonocytic leukemia: Two cases reports: A CARE-compliant article

RATIONALE

Thrombocytopenia in chronic myelomonocytic leukemia (CMML) is usually attributed to impaired marrow production resulting from cytotoxic drug use or CMML itself ("CMML-induced thrombocytopenia"). In very rare cases, immune thrombocytopenia (ITP) can be a complication of CMML ("CMML-associated ITP"). However, treatment of severe thrombocytopenia in patients with CMML is still a challenge.

PATIENT CONCERNS

Case 1 was a 61-year-old female patient admitted to our hospital because of skin petechiae and purpura for 6 days. She had increased monocyte cell count (1.82 × 10/L), markedly decreased platelet count (2 × 10/L), hypercellularity of the megakaryocyte lineage with many immature megakaryocytes, and ZRSR2(zinc finger CCCH-type, RNA binding motif and serine/arginine rich 2) mutation. She failed to the treatment of corticosteroids, intravenous immunoglobulin (IVIg), TPO (thrombopoietin), and cyclosporin A (CsA). Case 2 was a 72-year-old female patient with thrombocytosis and monocytosis for 4 years, and thrombocytopenia for 6 months. After 10 courses of decitabine therapy, she had a persistent severe thrombocytopenia and decreased number of megakaryocytes, TET2 (tet methylcytosine dioxygenase 2) and SRSF2 (serine and arginine rich splicing factor 2) mutations were detected. She was dependent on platelet transfusion.

DIAGNOSES

Case 1 was diagnosed as CMML-associated ITP, and case 2 as CMML with decitabine therapy-induced thrombocytopenia.

INTERVENTIONS

Both patients were treated with eltrombopag.

OUTCOMES

In both patients, the platelet counts returned to the normal within 1 week after eltrombopag therapy. The platelet count in case 1 patient remained stable at 141-200 × 10/L for 20 months with stopping therapy for 3 months. In case 2 patient, eltrombopag was stopped 1 month later. Her platelet count decreased to 41 × 10/L, but was stable at ∼30 × 10/L for 3 months with platelet transfusion independency for 12 months. Both patients had no adverse effects with eltrombopag.

LESSONS

CMML-associated ITP is very rare and easily misdiagnosed. To the best of our knowledge, case 1 is the first reported case of the successful treatment of CMML-associated ITP with eltrombopag. Both CMML-associated ITP and decitabine therapy-induced thrombocytopenia in these 2 patients were highly sensitive and safe to eltrombopag therapy.

New Alert Message Settings for the XN-series Automated Hematology Analyzer Are Useful for Avoiding Falsely High WBC Counts and to Detect Specimens with Giant Platelets

We encountered blood specimens from a patient with MYH9 related diseases, which gave falsely high white blood cell (WBC) counts during laboratory analysis using Sysmex XN-series automated hematology analyzers. This overcount was revealed to be caused by the overlapping of platelet (PLT) distribution with the WBC area in the WNR channel, which was used for routine WBC count with the XN-series. On the other hand, the WBC count obtained through the WDF channel of the XN-series seemed more accurate in such a case. We then created and introduced alert message settings for such rare but critical specimens, which gives a warning when the discrepancy in WBC counts between the WNR and WDF channels is higher than 1.0×10⁹/L. By using the alert message setting, we were able to detect some specimens which gave falsely high WBC counts with the routine WNR channel from three other cases of giant PLTs. In conclusion, our alert message setting seems useful in avoiding false reporting of WBC count due to abnormal cells, including giant PLTs.

Fatal Flea-Borne Typhus in Texas: A Retrospective Case Series, 1985-2015

AbstractFlea-borne (murine) typhus is a global rickettsiosis caused by Rickettsia typhi. Although flea-borne typhus is no longer nationally notifiable, cases are reported for surveillance purposes in a few U.S. states. The infection is typically self-limiting, but may be severe or life-threatening in some patients. We performed a retrospective review of confirmed or probable cases of fatal flea-borne typhus reported to the Texas Department of State Health Services during 1985-2015. When available, medical charts were also examined. Eleven cases of fatal flea-borne typhus were identified. The median patient age was 62 years (range, 36-84 years) and 8 (73%) were male. Patients presented most commonly with fever (100%), nausea and vomiting (55%), and rash (55%). Respiratory (55%) and neurologic (45%) manifestations were also identified frequently. Laboratory abnormalities included thrombocytopenia (82%) and elevated hepatic transaminases (63%). Flea or animal contact before illness onset was frequently reported (55%). The median time from hospitalization to administration of a tetracycline-class drug was 4 days (range, 0-5 days). The median time from symptom onset to death was 14 days (range, 1-34 days). Flea-borne typhus can be a life-threatening disease if not treated in a timely manner with appropriate tetracycline-class antibiotics. Flea-borne typhus should be considered in febrile patients with animal or flea exposure and respiratory or neurologic symptoms of unknown etiology.

Eltrombopag, a thrombopoietin mimetic, crosses the blood-brain barrier and impairs iron-dependent hippocampal neuron dendrite development

Essentials Potential neurodevelopmental side effects of thrombopoietin mimetics need to be considered. The effects of eltrombopag (ELT) on neuronal iron status and dendrite development were assessed. ELT crosses the blood-brain barrier and causes iron deficiency in developing neurons. ELT blunts dendrite maturation, indicating a need for more safety studies before neonatal use.

SUMMARY

Background Thrombocytopenia is common in sick neonates. Thrombopoietin mimetics (e.g. eltrombopag [ELT]) might provide an alternative therapy for selected neonates with severe and prolonged thrombocytopenia, and for infants and young children with different varieties of thrombocytopenia. However, ELT chelates intracellular iron, which may adversely affect developing organs with high metabolic requirements. Iron deficiency (ID) is particularly deleterious during brain development, impairing neuronal myelination, dopamine signaling and dendritic maturation and ultimately impairing long-term neurological function (e.g. hippocampal-dependent learning and memory). Objective To determine whether ELT crosses the blood-brain barrier (BBB), causes neuronal ID and impairs hippocampal neuron dendrite maturation. Methods ELT transport across the BBB was assessed using primary bovine brain microvascular endothelial cells. Embryonic mouse primary hippocampal neuron cultures were treated with ELT or deferoxamine (DFO, an iron chelator) from 7 days in vitro (DIV) through 14 DIV and assessed for gene expression and neuronal dendrite complexity. Results ELT crossed the BBB in a time-dependent manner. 2 and 6 μm ELT increased Tfr1 and Slc11a2 (iron-responsive genes involved in neuronal iron uptake) mRNA levels, indicating neuronal ID. 6 μm ELT, but not 2 μm ELT, decreased BdnfVI, Camk2a and Vamp1 mRNA levels, suggesting impaired neuronal development and synaptic function. Dendrite branch number and length were reduced in 6 μm ELT-treated neurons, resulting in blunted dendritic arbor complexity that was similar to DFO-treated neurons. Conclusions Eltrombopag treatment during development may impair neuronal structure as a result of neuronal ID. Preclinical in vivo studies are warranted to assess ELT safety during periods of rapid brain development.

Hematologic manifestations of babesiosis

BACKGROUND

Babesiosis, a zoonotic parasitic infection transmitted by the Ixodes tick, has become an emerging health problem in humans that is attracting attention worldwide. Most cases of human babesiosis are reported in the United States and Europe. The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia. The infection is usually asymptomatic or self-limited in the immunocompetent host, or follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients. Hematologic manifestations of the disease are common. They can range from mild anemia, to severe pancytopenia, splenic rupture, disseminated intravascular coagulopathy (DIC), or even hemophagocytic lymphohistiocytosis (HLH).

CASE PRESENTATION

A 70 year old immunocompetent female patient living in New York City presented with a persistent fever, night sweats, and fatigue of 5 days duration. Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia. Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR. Bone marrow biopsy was remarkable for dyserythropoiesis, suggesting possible HLH, supported by other blood workup meeting HLH-2004 trial criteria.

CONCLUSION

Human babesiosis is an increasing healthcare problem in the United States that is being diagnosed more often nowadays. We presented a case of HLH triggered by Babesia microti that was treated successfully. Also, we presented the hematologic manifestations of this disease along with their pathophysiologies.

The Amelioration of Myelofibrosis with Thrombocytopenia by a JAK1/2 Inhibitor, Ruxolitinib, in a Post-polycythemia Vera Myelofibrosis Patient with a JAK2 Exon 12 Mutation

Less than 5% of patients with polycythemia vera (PV) show JAK2 exon 12 mutations. Although PV patients with JAK2 exon 12 mutations are known to develop post-PV myelofibrosis (MF) as well as PV with JAK2V617F, the role of JAK inhibitors in post-PV MF patients with JAK2 exon 12 mutations remains unknown. We describe how treatment with a JAK1/2 inhibitor, ruxolitinib, led to the rapid amelioration of marrow fibrosis, erythrocytosis and thrombocytopenia in a 77-year-old man with post-PV MF who carried a JAK2 exon 12 mutation (JAK2H538QK539L). This case suggests that ruxolitinib is a treatment option for post-PV MF in patients with thrombocytopenia or JAK2 exon 12 mutations.

Fatal antiphospholipid syndrome following endoscopic transnasal-transsphenoidal surgery for a pituitary tumor: A case report

INTRODUCTION

The fatal type of antiphospholipid syndrome is a rare but life-threating condition. It may be triggered by surgery or infection. Endoscopic transnasal-transsphenoidal surgery is a common procedure for pituitary tumor. We report a catastrophic case of a young woman died of fatal antiphospholipid syndrome following endoscopic transnasal-transsphenoidal surgery.

METHODS AND RESULT

A 31-year-old woman of a history of stroke received endoscopic transnasal-transsphenoidal surgery for a pituitary tumor. The whole procedure was smooth. However, the patient suffered from acute delirium on postoperative day 4. Then, her consciousness became comatose state rapidly with dilatation of pupils. Urgent magnetic resonance imaging of brain demonstrated multiple acute lacunar infarcts. The positive antiphosphoipid antibody and severe thrombocytopenia were also noted. Fatal antiphospholipid syndrome was diagnosed. Plasma exchange, corticosteroids, anticoagulant agent were prescribed. The hemodynamic condition was gradually stable. However, the consciousness was still in deep coma. The patient died of organ donation 2 months later.

CONCLUSION

If patients have a history of cerebral stroke in their early life, such as a young stroke, the APS and higher risk of developing fatal APS after major surgery should be considered. The optimal management of APS remains controversial. The best treatment strategies are only early diagnosis and aggressive therapies combing of anticoagulant, corticosteroid, and plasma exchange. The intravenous immunoglobulin is prescribed for patients with refractory APS.

Central venous catheter placement in children with thrombocytopenia

BACKGROUND

The use of central venous catheter (CVC) is essential in the management of chronically ill children. Thrombocytopenia is a common hematological finding in these patients, with an increased risk of bleeding during the insertion of CVC. No clear guidelines are reported regarding the CVC positioning in patients with disorders of hemostasis, and prophylactic platelet (PLT) transfusions are still controversial. Aim of this study was to report the bleeding risk in pediatric patients with thrombocytopenia who underwent positioning of CVC.

METHODS

A retrospective single-center study of all CVCs surgically inserted over a 2-year period (April 2011 - April 2013) at our institution was performed. Age, gender, diagnosis, type of CVC, hematological values (hemoglobin and PLT count, prothrombin international normalized ratio, active partial thromboplastin time) and post-operative bleeding complications were compared between patients with PLT count below (group A) and above 50×109/L (group B).

RESULTS

Seventy-two CVC procedures were performed in 67 patients, with a median age of 45 months. Of these, 25 (35%) catheters were positioned in 25 patients included in group A and the remaining 47 (65%) in 42 patients in group B. All twenty-five cases in group A received a prophylactic PLT transfusion prior to the procedure. Bleeding complications were reported in only two cases in group A (8%).

CONCLUSIONS

CVC placement in pediatric patients with thrombocytopenia can be safely performed. We believe a randomized multicenter study could be necessary to determine the benefit of PLT transfusions in children with a PLT count below the recommended level of 50×109/L.

Heparin-Induced Thrombocytopenia and Graft Thrombosis following Endovascular Aneurysm Repair

Purpose:

To report a case of heparin-induced thrombocytopenia (HIT) complicated by stent-graft thrombosis.

Case Report:

An 82-year-old woman underwent endovascular aortic aneurysm repair using a Zenith stent-graft. She returned 2 weeks later with an occluded graft limb, large quantities of thrombus lining the remainder of the stent-graft, thrombocytopenia, and antiplatelet antibodies. There were no signs of kinking or compression of the graft, nor was there any thrombosis of the native arteries downstream from the occluded graft limb. Thrombolysis restored graft patency. Anticoagulation was induced using hirudin and warfarin. The graft remains patent at 6-month follow-up.

Conclusion:

HIT is a rare cause of postoperative endograft thrombosis. In this case, the presumed source of the inciting heparin dosage was the stent-graft itself, which had been soaked in a concentrated heparin solution prior to insertion.

[Quantities and function of NK cells in patients with positive BMMNC-Coombs test and cytopenia]

OBJECTIVE

To test NK cell quantities and function in patients with positive BMMNC-Coombs test (CBCPC) and cytopenia and to explore how NK cell participate in the progress of this disease.

METHODS

The percentage of CD3(-)CD56(+) NK cell in peripheral blood lymphocytes, the expression of activating receptor (NKG2D, NKp46, NKp44), inhibitory receptor (CD158a, CD158b), perforin and granzyme-β were detected by flow cytometry. All samples were taken from 42 patients (22 newly diagnosed and 20 in remission) and 12 healthy volunteers. The correlation between the above parameters and patients' clinical profile were evaluated.

RESULTS

①The percentage of CD3(-)CD56(+) NK cell in new diagnosed and remission CBCPC patients were significantly lower than that in healthy control [(10.04 ± 5.33)% vs (19.94 ± 7.38)%; (11.62 ± 6.80)% vs (19.94 ± 7.38)%, all P<0.01]. ② The expression of activating receptor NKG2D in new diagnosed CBCPC patients was significantly higher than that in remission group and healthy control [(74.03±18.24)% vs (45.97±29.45)%; (74.03±18.24)% vs (41.89± 15.34)% , P <0.01]. ③The expression of inhibitory receptor CD158a in new diagnosed CBCPC patients was significantly lower than that in remission group and healthy control (median: 3.72% vs 16.10%, P= 0.015; 3.72% vs 11.04%, P=0.025). ④The expression of perforin in new diagnosed and remitted CBCPC patients were significantly higher than that in healthy controls [(75.71±10.14) % vs (57.20±18.85)%, P= 0.018; (77.88±22.82)% vs (57.20±18.85)%, P=0.008]. ⑤The product of NK cell percentage and perforin expression in new diagnosed and remission CBCPC patient were significantly lower than that in healthy control [(7.68±4.54)% vs (12.13±5.19)%, P=0.011; (8.24±5.80)% vs (12.13±5.19)%, P=0.023]. The product of NK cell percentage and granzyme-β expression in the new diagnosed and remission CBCPC patient were significantly lower than that in healthy control [(7.83±5.26)% vs (14.79±8.37)%, P=0.008; (8.37 ± 6.83)% vs (14.79±8.37)%, P=0.012].

CONCLUSION

Deceased quantities and impaired total NK function might play a role in pathogenesis of CBCPC.

Clinical efficacy of neoadjuvant chemotherapy with irinotecan (CPT-11) and nedaplatin followed by radical hysterectomy for locally advanced cervical cancer

OBJECTIVE

To investigate the clinical efficacy of neoadjuvant chemotherapy (NAC) with irinotecan (CPT-11) and nedaplatin (NED) followed by radical hysterectomy.

METHODS

Patients with locally advanced cervical cancer (stage Ib2-IIb) were treated with NAC followed by surgery, primary surgery or primary radiotherapy. NAC was usually performed using transuterine arterial chemotherapy (TUAC) or intravenous CPT-11/NED. Survival rates were analysed in the three treatment groups; response rates and adverse events associated with NAC, TUAC and CPT-11/NED were compared, along with previously reported adverse events of chemoradiotherapy.

RESULTS

A total of 165 patients with cervical cancer were recruited. Of these, 70 were treated with NAC followed by surgery (48 with CPT-11/NED, 18 with TUAC and four with other types of chemotherapy), 73 were treated with primary surgery and 22 with primary radiotherapy (including chemoradiotherapy). There were no significant differences in progression-free survival or overall survival rates between the three treatment groups. The response rates for the NAC regimen of CPT-11/NED and TUAC were high (75% and 78%, respectively). The frequency of severe thrombocytopenia was lower in patients receiving CPT-11/NED compared with TUAC, and the incidence of severe anaemia, vomiting and cystitis was lower in patients receiving CPT-11/NED compared with chemoradiotherapy.

CONCLUSIONS

The use of CPT-11/NED as a NAC regimen shows favourable activity, with lower toxicity compared with NAC using TUAC or chemoradiotherapy, for the treatment of locally advanced cervical cancer.

Clinical Features of Systemic Lupus Erythematosus Patients Complicated With Evans Syndrome: A Case-Control, Single Center Study

The aim of the study was to investigate the clinical features of systemic lupus erythematous (SLE) complicated with Evans syndrome (ES). We conducted a retrospective case-control study to compare the clinical and laboratory features of age- and gender-matched lupus patients with and without ES in 1:3 ratios. In 5724 hospitalized SLE patients, we identified 27 (0.47%, 22 women and 5 men, average age 34.2 years) SLE patients complicated with ES. Fifteen patients (55.6%) presented with hematologic abnormalities initially, including 6 (22.2%) cases of isolated ITP, 4 (14.8%) cases of isolated AIHA, and 5 (18.5%) cases of classical ES. The median intervals between hematological presentations the diagnosis of SLE was 36 months (range 0-252). ES developed after the SLE diagnosis in 4 patients (14.8%), and concomitantly with SLE diagnosis in 8 patients (29.6%). Systemic involvements are frequently observed in SLE patients with ES, including fever (55.6%), serositis (51.9%), hair loss (40.7%), lupus nephritis (37%), Raynaud phenomenon (33.3%), neuropsychiatric (33.3%) and pulmonary involvement (25.9%), and photosensitivity (25.9%). The incidence of photosensitivity, hypocomplementemia, elevated serum IgG level, and lupus nephritis in patients with ES or without ES was 25.9% vs 6.2% (P = 0.007), 88.9% vs 67.1% (P = 0.029), 48.1% vs 24.4% (P = 0.021), and 37% vs 64.2% (P = 0.013), respectively. Twenty-five (92.6%) patients achieved improvement following treatment of glucocorticoids and immunosuppressants as well as splenectomy, whereas 6 patients experienced the relapse and 1 patient died from renal failure during the follow-up. ES is a relatively rare complication of SLE. Photosensitivity, hypocomplementemia, and elevated serum IgG level were frequently observed in ES patients, but lupus nephritis was less observed. More than half of patients presented with hematological manifestation at onset, and progress to typical lupus over months to years. Therefore, monitoring with antoantibodies profile as well as nonhematological presentations are necessary for patients with ITP and (or) AIHA.

Thrombocytopenia and platelet transfusion in the neonate

Neonatal thrombocytopenia is widespread in preterm and term neonates admitted to neonatal intensive care units, with up to one-third of infants demonstrating platelet counts <150 × 10(9)/L. Thrombocytopenia may arise from maternal, placental or fetal/neonatal origins featuring decreased platelet production, increased consumption, or both mechanisms. Over the past years, innovations in managing neonatal thrombocytopenia were achieved from prospectively obtained clinical data on thrombocytopenia and bleeding events, animal studies on platelet life span and production rate and clinical use of fully automated measurement of reticulated platelets (immature platelet fraction). This review summarizes the pathophysiology of neonatal thrombocytopenia, current management including platelet transfusion thresholds and recent developments in megakaryopoietic agents. Furthermore, we propose a novel index score for bleeding risk in thrombocytopenic neonates to facilitate clinician's decision-making when to transfuse platelets.

Quantification of the Blood Platelet Reactivity in the ADP-Induced Model of Non-Lethal Pulmonary Thromboembolism in Mice with the Use of Laser Doppler Flowmetry

Introduction

The paper describes an alternative method for quantification of in vivo ADP-induced thromboembolism. The aim of the studies was to develop a method of quantification which would not require either extravasation or labelling of platelets. Our proposed approach is based on the monitoring of changes of blood flow with the use of laser Doppler flowmetry.

Materials and Methods

Mice of C57Bl strain were used in the study. ADP was injected to the vena cava and blood flow was monitored with the use of a laser Doppler flowmeter in the mesentery. Measurements in platelet-depleted mice, mice pretreated with cangrelor, an ADP receptor antagonist, and eptifibatide, a blocker of fibrinogen binding to GPIIbIIIa, were conducted as the proof-of-concept in the performed experiments. Intravital microscopy and ex vivo imaging of organs was performed to identify the sites of aggregate formation resulting from ADP injection.

Results

The injection of ADP resulted in a dose-dependent reduction of the blood flow in the mesentery. These responses were fully attributable to blood platelet aggregation, as shown by the lack of the effect in platelet-depleted mice, and significantly reduced responses in mice pretreated with cangrelor and eptifibatide. No platelet aggregate formation in mesenteric vessels was revealed by intravital microscopy, while ex vivo imaging showed accumulation of fluorescent labelled platelets in the lung.

Conclusions

Injection of ADP to the venous system results in the formation of platelet aggregates predominantly in the lung. This results in reversible blood flow cessation in peripheral blood vessels. The measurement of this blood flow cessation in the mesentery allows indirect measurement of ADP-induced pulmonary thromboembolism. We suggest that this approach can be useful for in vivo screening for antiplatelet drug candidates.

Bacterial Pneumonia-induced Persistent Remission of Severe Immune Thrombocytopenia after Allogeneic Hematopoietic Stem Cell Transplantation

A 53-year-old woman with chronic myeloid leukemia received allogeneic hematopoietic stem cell transplantation. After neutrophil engraftment, her platelet count exceeded 100,000/μL at day 64. While she was receiving corticosteroid treatment for chronic graft versus host disease (GVHD), her platelets suddenly dropped to 6,000/μL at day 210 and she was diagnosed with immune thrombocytopenia (ITP). Corticosteroids, intravenous high-dose gamma globulin (IVIg) and a splenectomy failed to increase her platelet count. She developed bacterial pneumonia at day 599 and antibiotic therapy was initiated. Soon after, her platelet count continuously increased. Her GVHD and ITP are now in remission without any ongoing treatment.

EPIDEMIOLOGY, CLINICAL AND LABORATORY FEATURES OF CRIMEAN-CONGO HEMORRHAGIC FEVER IN GEORGIA

Crimean-Congo hemorrhagic fever virus transmitted to humans by Hyalomma ticks or by direct contact with the blood of infected humans or domestic animals. The most common clinical signs of CCHF are fever, nausea, headache, diarrhea, myalgia, petechial rash, and bleeding. CCHF is a severe disease in humans with a fatality rate up to 15-85%. This study was undertaken to determine the predictors of fatality among patients with CCHF based on epidemiological, clinical, and laboratory findings. 34 patients were enrolled in the study, aged 4 to 77; 17 - male and 17 female. 3 of them were fatal cases. All of them were from Shua Kartli: Khashuri, Gori and Kaspi districts, involved in farming/handling livestock and the history of tick bite was present in most of patients. Evaluation of the epidemiological characteristics of this cases showed that the female to male ratio was nearly similar. The disease is common in the rural areas of the region, mostly in the actively working age group and almost all patients were farmers. The results of our study show that the most cardinal clinical and laboratory features of Crimean-Congo hemorrhagic fever are - acute beginning of disease, high fever, intoxication and hemorrhagic symptoms, thrombocytopenia, high level of aminotransferases and creatine. Predictors of fatality are: an altered mental status, in early stage of disease dramatic decreased thrombocytes count and significantly high level of aspartate aminotransferase, also longer the mean prothrombin time and INR.

HEMOSTATIC STUDIES IN DENGUE PATIENTS

The pathogenesis of hematologic changes in dengue patients is not clearly understood. Consistent hematological findings include vasculopathy, thrombocytopenia, and coagulopathy. There are evidences suggesting that dengue virus causes pathophysiological changes that involve all of the consistent hematologic findings resulting in vasculopathy, reduction in platelet number as well as platelet dysfunction, and reduction of several coagulation factors. Laboratory evidences of disseminated intravascular coagulation (DIC) are also demonstrated in all degrees of severity in dengue patients. Only in severe dengue cases is profound DIC aggravated, leading to uncontrolled bleeding and death. A study to determine the extent of the activation of endothelial cells and the hemostatic system in correlation with clinical severity and also to detect the best prognostic factor for severe dengue showed plasma von Willebrand factor antigen (VWF:Ag) to be the best indicator of progression to severe dengue.

Wilson disease with thrombocytopenia (case report)

We present an adolescent patient with WD accompanied with secondary amenorrhea, and thrombocytopenia. NK, a 14 year-old girl, had amenorrhea for 5 months despite having had regular menses for 2 years. An abdominal ultrasound scan revealed ascitis and some ovarian cysts. On physical examination: slight jaundice, edema of lower extremities, skin purpuric rash, enlarged abdomen, dry skin. She had no hepatomegaly and no splenomegaly. Breast and pubic hair development was concomitant with Tanner stage 4. There was performed laboratory and instrumental investigations. The patient was diagnosed as WD owing to the low level of ceruloplasmin, with increased level of copper in 24-hour urine excretion and in dry liver tissue. The needle biopsy of liver showed severe hepatocellular necrosis, inflammatory changes and fibrosis. The platelet count was found to be low with lack of increased number of megakaryocytes in the bone marrow aspiration suggesting the thrombocytopenia was not exclusively owing to hypersplenism. The absence of antithrombocyte and other autoimmune and viral antibodies excluded respectively the diagnosis of autoimmune thrombocytopenia, other autoimmune diseases and viral infections. Thus, we support the recommendation that adolescents with amenorrhea or children with thrombocytopenia without any obvious cause should be evaluated for WD, because the early detection and treatment of WD is capable of reversing described changes and restoring a normal liver function.

Thrombocytopenia in pegylated interferon and ribavirin combination therapy for chronic hepatitis C

BACKGROUND

This study aimed to examine the therapeutic effect and prognostic indicators of pegylated interferon (PEG-IFN) and ribavirin (RBV) combination therapy in thrombocytopenic patients with chronic hepatitis C, hepatitis C virus (HCV)-related cirrhosis, and those who underwent splenectomy or partial splenic embolization (PSE).

METHODS

Of 326 patients with HCV-related chronic liver disease (252 with genotype 1b and 74 with genotype 2a/2b) treated with PEG-IFN/RBV, 90 were diagnosed with cirrhosis.

RESULTS

Regardless of the degree of thrombocytopenia, the administration rate was significantly higher in the splenectomy/PSE group compared to the cirrhosis group. However, in patients with genotype 1b, the sustained virological response (SVR) rate was significantly lower in the cirrhosis and the splenectomy/PSE groups compared to the chronic hepatitis group. No cirrhotic patients with platelets less than 80,000 achieved an SVR. Patients with genotype 2a/2b were more likely to achieve an SVR than genotype 1b. Prognostic factors for SVR in patients with genotype 1b included the absence of esophageal and gastric varices, high serum ALT, low AST/ALT ratio, and the major homo type of the IL28B gene. Splenectomy- or PSE-facilitated induction of IFN in patients with genotype 2a/2b was more likely to achieve an SVR by an IFN dose maintenance regimen. Patients with genotype 1b have a low SVR regardless of splenectomy/PSE. In particular, patients with a hetero/minor type of IL28B did not have an SVR.

CONCLUSIONS

Splenectomy/PSE for IFN therapy should be performed in patients expected to achieve a treatment response, considering their genotype and IL28B.

Platelet dynamics during natural and pharmacologically induced torpor and forced hypothermia

Hibernation is an energy-conserving behavior in winter characterized by two phases: torpor and arousal. During torpor, markedly reduced metabolic activity results in inactivity and decreased body temperature. Arousal periods intersperse the torpor bouts and feature increased metabolism and euthermic body temperature. Alterations in physiological parameters, such as suppression of hemostasis, are thought to allow hibernators to survive periods of torpor and arousal without organ injury. While the state of torpor is potentially procoagulant, due to low blood flow, increased viscosity, immobility, hypoxia, and low body temperature, organ injury due to thromboembolism is absent. To investigate platelet dynamics during hibernation, we measured platelet count and function during and after natural torpor, pharmacologically induced torpor and forced hypothermia. Splenectomies were performed to unravel potential storage sites of platelets during torpor. Here we show that decreasing body temperature drives thrombocytopenia during torpor in hamster with maintained functionality of circulating platelets. Interestingly, hamster platelets during torpor do not express P-selectin, but expression is induced by treatment with ADP. Platelet count rapidly restores during arousal and rewarming. Platelet dynamics in hibernation are not affected by splenectomy before or during torpor. Reversible thrombocytopenia was also induced by forced hypothermia in both hibernating (hamster) and non-hibernating (rat and mouse) species without changing platelet function. Pharmacological torpor induced by injection of 5'-AMP in mice did not induce thrombocytopenia, possibly because 5'-AMP inhibits platelet function. The rapidness of changes in the numbers of circulating platelets, as well as marginal changes in immature platelet fractions upon arousal, strongly suggest that storage-and-release underlies the reversible thrombocytopenia during natural torpor. Possibly, margination of platelets, dependent on intrinsic platelet functionality, governs clearance of circulating platelets during torpor.

Management of thrombocytopenia due to liver cirrhosis: A review

Thrombocytopenia is a common complication in liver disease and can adversely affect the treatment of liver cirrhosis, limiting the ability to administer therapy and delaying planned surgical/diagnostic procedures because of an increased risk of bleeding. Multiple factors, including splenic sequestration, reduced activity of the hematopoietic growth factor thrombopoietin, bone marrow suppression by chronic hepatitis C virus infection and anti-cancer agents, and antiviral treatment with interferon-based therapy, can contribute to the development of thrombocytopenia in cirrhotic patients. Of these factors, the major mechanisms for thrombocytopenia in liver cirrhosis are (1) platelet sequestration in the spleen; and (2) decreased production of thrombopoietin in the liver. Several treatment options, including platelet transfusion, interventional partial splenic embolization, and surgical splenectomy, are now available for severe thrombocytopenia in cirrhotic patients. Although thrombopoietin agonists and targeted agents are alternative tools for noninvasively treating thrombocytopenia due to liver cirrhosis, their ability to improve thrombocytopenia in cirrhotic patients is under investigation in clinical trials. In this review, we propose a treatment approach to thrombocytopenia according to our novel concept of splenic volume, and we describe the current management of thrombocytopenia due to liver cirrhosis.

[Pulmonary artery catheterization in patients with blood diseases]

PURPOSE OF THE STUDY

To analyze complications of the pulmonary artery catheterization in patients with blood diseases.

MATERIALS AND METHODS

93 cases of pulmonary artery catheterization in patients with blood diseases were included in the retrospective study.

RESULTS

Indications for pulmonary artery catheterization were septic shock (78.5%) and acute respiratory failure (21.5%). In 31 cases (33.3%) pulmonary artery catheterization was performed in conditions of agranulocytosis and in 81 cases (87%) in conditions of thrombocytopenia (platelets median 43 x 109 per liter minimal 7 x 109, maximal 150 x 109 per liter). Patients received transfusions of platelets in case of thrombocytopenia less than 30 x 109 per liter. Early complications of pulmonary artery catheterization occurred in 5 patients with thrombocytopenia (5.4%), the complications was connected with bleeding (hematoma, bleeding from place of puncture, lung bleeding) and mechanical (arterial puncture, pneumothorax, hemothorax). Number of attempts of the central vein catheterization was risk factor the complications. The frequency of catheter-associated sepsis was 5.89 cases each 1000 catheter-days and the frequency of infections of the soft tissues was 9.78 cases each 1000 catheter-days. Catheter-associated infection complications occurred in cases of catheter use over 5 days. Catheter-associated sepsis occurred in 2 of 3 patients with agranulocytosis. Other complications included intermittent arrhythmias during catheter moving in the heart chambers (58), catheter balloon rupture (4), and thrombosis of catheter lumen (3).

CONCLUSIONS

Pulmonary artery catheterization can be used in patients with blood diseases and first of all in cases of septic shock and acute respiratory failure. Alternative less invasive methods of monitoring should be used in patients with agranulocytosis.

Autoimmune polyglandular syndrome presenting with jaundice and thrombocytopenia

OBJECTIVE

To report an uncommon presentation of a rare case of autoimmune polyglandular syndrome type IIIb in an elderly woman.

CLINICAL PRESENTATION AND INTERVENTION

A 62-year-old woman presented with anaemic symptoms and jaundice. Blood tests showed macrocytic anaemia due to vitamin B12 deficiency with Coombs negative haemolysis. A thyroid function test was consistent with hypothyroidism. Autoimmune antibody assays were positive for anti-parietal cell, anti-intrinsic factor and anti-thyroid peroxidase antibodies. A final diagnosis of autoimmune thyroiditis with pernicious anaemia, which constituted autoimmune polyglandular syndrome type IIIb, was made and the patient was treated with L-thyroxine, vitamin B12 injection and a blood transfusion. She was discharged uneventfully after a week of hospitalization.

CONCLUSION

This case showed that the presence of one autoimmune endocrine disease should prompt clinicians to look for other coexisting autoimmune diseases which may be asymptomatic despite positive autoantibodies.