Safety and efficacy of romiplostim in children and adolescents with Immune thrombocytopenia: A systematic review

Abstract Objective To evaluate the efficacy and safety of romiplostim (thrombopoietin-receptor agonist) in the treatment of pediatric immune thrombocytopenia (ITP). Methods Searches were conducted in MEDLINE, EMBASE, LILACS, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov (from January 2011 to August 2021). Randomized controlled trials (RCTs), double-blind, comparing romiplostim with a placebo in pediatric persistent or chronic ITP were included. The primary outcome was the overall response rate (platelets ≥ 50 × 109/L) in the absence of rescue therapy for at least two consecutive weeks. The secondary endpoints were the minimization of clinically significant bleeding and the necessity for rescue treatments and the maximization of safety (incidence of overall adverse events) and durable response (maintaining platelet counts for at least twelve weeks). Results Two double-blind randomized placebo-controlled trials (84 participants) were included in this systematic review. Our data showed that, compared to the placebo group, the proportion of patients achieving durable platelet response was significantly higher in the romiplostim group (p= 0.003, RR = 6.34, 95%CI = 1.89 - 21.23), as was the overall response in the romiplostim group (p= 0.002, RR = 3.62, 95%CI = 1.63 - 8.03). Significant bleeding incidents (p= 0.49), overall adverse events (p= 0.71) and the need for rescue treatment (p= 0.13) were not statistically different between the romiplostim and placebo groups. Conclusions Romiplostim might improve both durable and overall platelet response in children and adolescents with ITP, compared to a placebo. More clinical trials are needed to evaluate the efficacy and safety of romiplostim and to compare it with other second-line treatments that are being used in pediatric ITP.

Polimorfismos genéticos implicados en el desarrollo de la purpura trombocitopénica inmune / Genetic polymorphisms involved in the development of Immune Thrombocytopenic Purpura

Introducción: los cambios en el ácido desoxirribonucleico se conocen como mutaciones, estas dan lugar a los polimorfismos, los cuales generan variación alélica entre individuos y diversidad de la misma especie. Se ha sugerido que los polimorfismos genéticos en los mediadores inmunitarios desempeñan un papel fundamental en la patogénesis de muchos trastornos autoinmunes, como en la púrpura trombocitopénica inmune, siendo esta el tipo más común de púrpura trombocitopénica y, a menudo, se diagnostica como un tipo de trastorno autoinmune, debido a la destrucción de las plaquetas mediadas por el sistema inmunitario. Objetivo: realizar una revisión bibliográfica sobre el papel de los polimorfismos genéticos y su influencia en el desarrollo de la púrpura trombocitopénica inmune. Métodos: se realizó revisión literaria en inglés y español en PubMed y Elsevier, desde marzo hasta mayo del 2021, con el uso de combinación de palabras clave y términos MeSH, como púrpura trombocitopénica y polimorfismos genéticos. Se realizó análisis y resumen de la literatura encontrada. Conclusión: la púrpura trombocitopénica inmune es considerada como una patología multifactorial, causada por factores ambientales y genéticos, dentro de los cuales se encuentran los polimorfismos para los mediadores inmunitarios que pueden llevar a una exacerbación de la enfermedad o no intervenir en la misma.

Introduction: Changes in deoxyribonucleic acid are known as mutations, these give place to polymorphisms, which generate allelic variation between individuals and provide diversity among same species. Genetic polymorphisms in immune mediators have been suggested to play a key role in the pathogenesis of many autoimmune disorders, such as immune thrombocytopenic purpura, this being the most common type of thrombocytopenic purpura and is often diagnosed as a type of autoimmune disorder, due to the destruction of platelets mediated by the immune system. Objective: To execute a bibliographic review on the role of genetic polymorphisms and their influence on the development of immune thrombocytopenic purpura. Methods: A literary review in English and Spanish was performed in PubMed and Elsevier from March to May 2021, with the use of a combination of keywords and MeSH terms such as Thrombocytopenic Purpura and genetic polymorphisms. Analysis and summary of the literature found was executed. Conclusion: Immune thrombocytopenic purpura is considered a multifactorial pathology, caused by environmental and genetic factors, among which are polymorphisms for immune mediators that can lead to an exacerbation of the disease or not intervene in the same.

Clinical diagnosis and treatment of hereditary thrombocytopenia and purpura: a report of five cases and literature review / 中华血液学杂志

Objective: To report the clinical manifestations and laboratory features of five patients with congenital thrombotic thrombocytopenic purpura (cTTP) and explore its standardized clinical diagnosis and treatment along with a review of literature. Methods: Clinical data of patients, such as age of onset, disease manifestation, personal history, family history, and misdiagnosed disease, were collected. Treatment outcomes, therapeutic effects of plasma infusion, and organ function evaluation were observed. The relationship among the clinical manifestations, treatment outcomes, and ADAMTS13 gene mutation of patients with cTTP was analyzed. Additionally, detection of ADAMTS13 activity and analysis of ADAMTS13 gene mutation were explored. Results: The age of onset of cTTP was either in childhood or adulthood except in one case, which was at the age of 1. The primary manifestations were obvious thrombocytopenia, anemia, and different degrees of nervous system involvement. Most of the patients were initially suspected of having immune thrombocytopenia. Acute cTTP was induced by pregnancy and infection in two and one case, respectively. ADAMTS13 gene mutation was detected in all cases, and there was an inherent relationship between the mutation site, clinical manifestations, and degree of organ injury. Therapeutic or prophylactic plasma transfusion was effective for treating cTTP. Conclusions: The clinical manifestations of cTTP vary among individuals, resulting in frequent misdiagnosis that delays treatment. ADAMTS13 activity detection in plasma and ADAMTS13 gene mutation analysis are important bases to diagnose cTTP. Prophylactic plasma transfusion is vital to prevent the onset of the disease.

Effects of peripartum treatment on delivery outcomes in women with primary immune thrombocytopenia: a prospective cohort study / 中华围产医学杂志

Objective:To investigate the effects of peripartum administration of low-dose corticosteroids or intravenous immunoglobulin (IVIG) on delivery outcomes in pregnant patients with primary immune thrombocytopenia (ITP).Methods:This prospective cohort study involved pregnant women (≥34 gestational weeks) who were diagnosed with ITP in Peking University People's Hospital from January 2017 to December 2021. Their platelet counts were between 20×10 9/L to 50×10 9/L without bleeding and none of them had been treated with any medications. All patients were divided into medication group (prednisone or IVIG) and platelet transfusion group based on their preference. Differences in vaginal delivery rate, postpartum hemorrhage rate and platelet transfusion volume between the two groups were compared using t-test, Wilcoxon rank sum test and Chi-square test. Binary logistic regression was used to investigate the factors influencing the rates of vaginal delivery and postpartum hemorrhage. Multiple linear regression was used to analyze the factors influencing the platelet transfusion volume. Results:A total of 96 patients with ITP were recruited with 70 in the medication group and 26 in the platelet transfusion group. The vaginal delivery rate in the medication group was higher than that in the platelet transfusion group [60.0% (42/70) vs 30.8% (8/26), χ 2=6.49, P=0.013]. After adjusted by the proportion of multiparae and the gestational age at delivery, binary logistic regression showed that the increased vaginal delivery rate in patients undergoing the peripartum treatment ( OR=4.937, 95% CI: 1.511-16.136, P=0.008). The incidence of postpartum hemorrhage in the two groups was 22.9% (16/70) and 26.9% (7/26), respectively, but no significant difference was shown ( χ 2=0.17, P=0.789). The median platelet transfusion volume was lower in the medication group than in the platelet transfusion group [1 U(0-4 U) vs 1 U(1-3 U), Z=－2.18, P=0.029]. After adjustment of related factors including the platelet count at enrollment, obstetrical complications and anemia, multiple linear regression showed that the platelet transfusion volume was also lower in the medication group (95% CI:0.053-0.911, P=0.028). Ninety-six newborns were delivered without intracranial hemorrhage. The overall incidence of neonatal thrombocytopenia was 26.0% (25/96). There was no significant difference in birth weight, and incidence of neonatal asphyxia or thrombocytopenia between the two groups. Conclusion:Peripartum therapy in ITP patients may increase vaginal delivery rate and reduce platelet transfusion volume without causing more postpartum hemorrhage.

A Case of Off-Pump Coronary Artery Bypass Grafting Following High-Dose Dexamethasone Therapy in a Patient with Idiopathic Thrombocytopenic Purpura / 日本心臓血管外科学会雑誌

Man in his 70s, who had suffered from idiopathic thrombocytopenic purpura (ITP), was admitted to our hospital with chest pain at rest. Coronary angiography revealed obstruction of the right coronary artery and triple vessel disease. Because a bleeding tendency was expected during coronary artery bypass grafting, we performed percutaneous coronary intervention to the culprit lesion first, and then intravenous immunoglobulin and high dose dexamethasone were tried. His platelet count rose from 49,000 to 103,000/mm3, so we performed coronary artery bypass grafting. The patient had no postoperative hemorrhagic complications. We believe that high dose dexamethasone therapy is useful for patients with ITP who need surgery immediately.

A combined regimen based on bortezomib and glucocorticoids for 6 patients with recurrent/refractory immune thrombotic thrombocytopenic purpura / 中华血液学杂志

Objective: To observe the efficacy and adverse reactions of a combination therapy regimen based on bortezomib and glucocorticoids in recurrent/refractory immune thrombocytopenic purpura (iTTP) . Methods: Six patients with recurrent/refractory TTP were included and treated with a glucocorticoid and two courses of bortezomib-based regimen. The clinical remission status of patients, changes in ADAMTS13 activity/ADAMTS13 inhibitor, and the occurrence of treatment-related adverse reactions were observed. Results: Of the 6 patients, 2 were males and 4 were females, with a median age of 21.5 (18-68) years. Refractory TTP was found in 1 case and recurrent TTP in 5 cases. Glucocorticoids were administered with reference to prednisone at 1 mg·kg(-1)·d(-1), and gradually reduced in dosage after achieving clinical remission. Bortezomib is subcutaneously administered at 1.3 mg/m(2) on days 1, 4, 8, and 11 with a 28-day treatment course consisting of 2 courses. Six patients achieved clinical remission after receiving bortezomib as the main treatment. ADMATS13 activity returned to normal in all patients with TTP after treatment, and the ADAMTS13 inhibitor turned negative. Thrombocytopenia is the most common adverse reaction after treatment, with other adverse reactions, including peripheral neuritis and abdominal pain, but ultimately all patients returned to normal. In a median follow-up of 26 (9-41) months, 5 patients maintained sustained remission, and 1 patient relapsed after 16 months of bortezomib treatment. Conclusion: Combination therapy of bortezomib and glucocorticoids has a satisfactory therapeutic effect and controllable adverse reactions for recurrent/refractory iTTP.

Progress on diagnosis and treatment of kidney transplantation-associated thrombotic microangiopathy / 器官移植

Thrombotic microangiopathy (TMA) is a severe complication after kidney transplantation, mainly characterized by thrombocytopenia, microvascular hemolytic anemia and acute kidney injury, which may lead to kidney allograft failure or even death of the recipients. With the increasing quantity of solid organ transplantation in China and deeper understanding of TMA, relevant in-depth studies have been gradually carried out. Kidney transplantation-associated TMA is characterized with different causes and clinical manifestations. Non-invasive specific detection approach is still lacking. The diagnosis of TMA mainly depends on renal biopsy. However, most TMA patients are complicated with significant thrombocytopenia. Hence, renal puncture is a risky procedure. It is difficult to make a definite diagnosis. For kidney transplantation-associated TMA, plasma exchange, intravenous immunoglobulin and withdrawal of potential risk drugs are commonly employed. Nevertheless, the overall prognosis is poor. In this article, the classification of TMA after kidney transplantation, diagnosis and treatment of kidney transplantation-associated TMA were reviewed, aiming to provide reference for clinical diagnosis and treatment of kidney transplantation-associated TMA.

Microangiopatía trombótica como complicación de una pancreatitis aguda / Thrombotic microangiopathy as a complication of acute pancreatitis / Microangiopatia trombótica como complicação da pancreatite aguda

La púrpura trombótica trombocitopénica (PTT) es una microangiopatía trombótica poco frecuente, que se caracteriza por anemia hemolítica y plaquetopenia, con una elevada morbimortalidad. Su forma más frecuente es la PTT inmune, también denominada adquirida, provocada por la deficiencia de la enzima disintegrin-like and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13) secundaria a la presencia en plasma de autoanticuerpos. Presentamos el caso de un paciente con diagnóstico de pancreatitis aguda (PA) complicada con PTT, asociación de presentación excepcional en la práctica clínica.

Summary: Thrombotic thrombocytopenic purpura is rather an unusual thrombotic microangiopathy characterized by hemolytic anemia and plateletopenia which results in high morbimortality rates. The most frequent form of this disease is immune thrombotic thrombocytopenic purpura, also known as acquired thrombotic thrombocytopenic purpura, which is caused by enzime deficiency disintegrin-like and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13) that is secondary to antibodies in plasma. The study presents the case of a patient with a diagnosis of acute pancreatitis with a rare complication of thrombotic thrombocytopenic purpura which is exceptional in the clinical practice.

A púrpura trombocitopênica trombótica (PTT) é uma microangiopatia trombótica rara, caracterizada por anemia hemolítica e trombocitopenia, com alta morbimortalidade. Sua forma mais comum é a TTP imune, também conhecida como adquirida, que é causada pela deficiência da enzima ADAMTS13 (em inglês A disintegrin-like and metalloprotease with thrombospondin type 1 motif no. 13) secundária à presença de autoanticorpos no plasma. Apresentamos o caso de um paciente com diagnóstico de pancreatite aguda (PA) complicada por PTT, associação com apresentação excepcional na prática clínica.

Thrombotic thrombocytopenic purpura as an acute complication of COVID-19

Introduction: While disseminated intravascular coagulation (DIC) is a serious complication of COVID-19, a close differential in critically ill patients with thrombocytopenia is Thrombotic thrombocytopenic purpura (TTP). Case Report: We describe the case of a middle-aged lady admitted with COVID-19 pneumonia who developed progressive thrombocytopenia, altered sensorium and renal failure. The absence of coagulation abnormalities alerted to the possibility of TTP, strengthened by presence of schistocytes in peripheral smear. Conclusions: This case highlights the need for high index of suspicion and to pay attention to normal tests as well that might give clues to the diagnosis. New onset thrombocytopenia in COVID-19 need not always indicate DIC. A careful examination of peripheral smear may help diagnosing TTP especially if coagulation profile is normal.

MULTIPLE MYELOMA COMPLICATED BY FATAL THROMBOTIC THROMBOCYTOPENIC PURPURA (TTP) – A CASE REPORT OF AUTOPSY FINDINGS IN A TERTIARY CARE CENTRE.

Thrombotic thrombocytopenic purpura (TTP) is a syndrome characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurological abnormalities, fever and renal dysfunction. Early clinical suspicion and presumptive diagnosis of TTP helps in timely initiation of treatment modalities speci?c for TTP which may prove to be lifesaving and thus augment in reducing the mortality rate of TTP which is estimated to be 80 – 90 % if left untreated. We report a case of a known case of multiple myeloma who developed TTP which proved fatal despite plasmapheresis. Signi?cant autopsy ?ndings of presence of microthrombi in the microvasculature of multiple organs is also highlighted.

Management of Perioperative Anticoagulation in a Patient with Antiphospholipid Antibody Syndrome Undergoing Cardiac Surgery: A Case Report

Patients with Antiphospholipid syndrome (APLS) are at high risk for both bleeding and thrombotic complications during cardiac surgery involving cardiopulmonary bypass (CPB). In this case we present a patient with APLS and Immune Thrombocytopenic Purpura who successfully underwent aortic valve replacement (AVR) with CPB despite recent craniotomy for subdural hematoma evacuation. Anticoagulation for CPB was monitored by targeting an Activated Clotting Time (ACT) that was 2× the upper limit of normal. A multidisciplinary approach was essential in ensuring a safe and successful operation.

Púrpura trombocitopénica inmunológica tras vacunación contra COVID-19

RESUMEN Se presenta el caso de un paciente masculino con púrpura trombocitopénica inmunológica que ocurre 10 días después de la aplicación de la vacuna contra la COVID-19. Se descartaron con estudios complementarios todas las causas secundarias. Con pulsos de corticoides presentó mejoría clínica y laboratorial, evolucionando favorablemente. Asumiendo la relación temporal con dicha vacuna, se presume que esta plaquetopenia fue una reacción adversa a la misma. En el país no se han notificado casos de púrpura trombocitopénica inmunológica hasta el último boletín informativo de reacciones adversas relacionadas a esta vacuna.

ABSTRACT We present the case of a male patient with immunological thrombocytopenic purpura that occurs 10 days after the application of the COVID-19 vaccine. All secondary causes were ruled out with complementary studies. With corticosteroid pulses, he presented clinical and laboratory improvement, progressing favorably. Assuming the temporal relationship with the vaccine, it is presumed that this thrombocytopenia was an adverse reaction to it. No cases of immune thrombocytopenic purpura have been reported in the country until the last bulletin of adverse reactions related to this vaccine.

Concurrencia entre el síndrome de Guillain-Barré y púrpura trombocitopénica inmune posiblemente inducidos por COVID-19 prolongado / Concurrence between Guillain-Barré syndrome and immune thrombocytopenic purpura possibly induced by long COVID-19

RESUMEN Durante la infección aguda por el SARVS-CoV-2 se produce una desregulación del sistema inmune que puede durar hasta ocho meses después de controlado el cuadro agudo. Esto, sumado a otros factores, posiblemente este asociado con un aumento del riesgo de aparición y concurrencia de enfermedades autoinmunes. La aparición simultanea del síndrome de Guillain-Barré (SGB) y púrpura trombocitopénica (PTI) se ha reportado poco en la literatura, y el SGB raramente se asocia con otra enfermedad autoinmune. Presentamos el caso de un varón que luego de un mes de tener un cuadro agudo de COVID-19 moderado, presentó concurrentemente SGB y PTI con respuesta adecuada al tratamiento.

ABSTRACT During acute SARS-CoV-2 infection, there is persistent deregulation of the immune system that can last up to 8 months after the acute condition is controlled. This, added to other factors, is possibly associated with an increased risk of the appearance and concurrence of autoimmune diseases. The simultaneous occurrence of GBS and ITP has been rarely reported in the literature, and GBS is rarely associated with another autoimmune disease. We present the case of a man who, one month after his recovery from acute moderate COVID-19, presented concurrent GBS and ITP with an adequate response to treatment.

The paradox of thrombotic thrombocytopenic purpura and the TACO challenge!

Thrombotic thrombocytopenic purpura (TTP) is a rare medical emergency characterized by the pentad of microangiopathic hemolytic anemia, thrombocytopenia, fever, renal failure, and neurological dysfunction. TTP is an infrequent condition and is a thrombotic microangiopathy. TTP is essentially a clinical diagnosis. As untreated TTP has a high mortality, diagnosis is usually presumptive and prompt treatment with plasma exchange is highly beneficial and reduces mortality significantly. Therapeutic plasma exchange with fresh frozen plasma is the standard treatment of choice for TTP. Transfusion-associated reactions may occur in some patients further complicating the disease picture and prolonging hospital stay and recovery. Transfusion-associated circulatory overload and transfusion-associated acute lung injury are the leading cause of transfusion-related mortality. We present here the diagnostic and therapeutic challenges that we faced with a young male patient who presented with fever, jaundice, and seizures.

Relação entre a infecção por Helicobacter pylori e doenças hematológicas: uma revisão integrativa / The relationship between Helicobacter pylori infection and hematologic diseases: an integrative review

Helicobacter pylori, uma bactéria gram-negativa, desde 1984 vem sendo associada às doenças gástricas. A partir da década de 1990, surgiram crescentes relatos indicando a relação da infecção com manifestações extragástricas. Nesse sentido, o objetivo do estudo foi investigar, através de uma revisão integrativa, as evidências relacionadas à H. pylori e a presença de doenças hematológicas, focando na anemia por deficiência de ferro (ADF) e na púrpura trombocitopênica idiopática (PTI). Bases de dados foram consultadas com as palavras-chave e descritores Helicobacter pylori, Doenças extragástricas, Doenças hematológicas, Anemia ferropriva e Púrpura Trombocitopênica Idiopática, nos idiomas inglês, português e espanhol, combinados com o operador booleano "AND". Após a leitura de 1.964 títulos, 85 artigos atendiam aos critérios de inclusão. Com a exclusão dos artigos duplicados e pela análise dos resumos, 62 trabalhos foram selecionados e lidos na íntegra. Por fim, 27 estudos foram incluídos: 13 relacionados à ADF e 77% deles encontraram associação com H. pylori, e 14 relacionados à PTI, nos quais a relação com a bactéria foi encontrada em 93%. As evidências que associam essas doenças hematológicas com H. pylori são expressivas, portanto, mais estudos são necessários para elucidar os mecanismos relacionados e contribuir para prevenção, diagnóstico e tratamento mais eficazes.

Helicobacter pylori is a gram-negative bacterium that has been associated with gastric diseases since 1984. Since the 1990s, there have been increasing reports indicating that the infection may also be associated with extragastric manifestations. This integrative review aimed to investigate the evidence on the relationship between H. pylori and hematological diseases, specifically iron deficiency anemia (IDA) and idiopathic thrombocytopenic purpura (ITP). Databases were searched for the keywords "Helicobacter pylori," "extragastric diseases," "hematologic diseases," "iron deficiency anemia," and "idiopathic thrombocytopenic purpura" in English, Portuguese, and Spanish, combined with the boolean operator "AND." The search yielded 1,964 studies. After reading the titles, only 85 met the inclusion criteria. Sixty-two studies were selected for full-text reading after exclusion of duplicates and abstract analysis. Finally, 27 studies were included in this review. Thirteen studies addressed IDA, among which 77% found an association with H. pylori; whereas 14 studies addressed ITP, among which 93% found a relationship with H. pylori. There is strong evidence supporting the association between hematologic diseases and H. pylori. Further studies are needed to elucidate the mechanisms involved in this relationship, contributing to more effective prevention, diagnosis, and treatment.

A Case of Hemorrhagic Cystitis that Developed During Administration of Cyclophosphamide for Idiopathic Thrombocytopenic Purpura Successfully Treated with Kamikihito / 日本東洋医学雑誌

A 71-year-old woman was referred to our hospital with complaints of gross hematuria. She had been administered 50mg/day of cyclophosphamide for 13 years to treat idiopathic thrombocytopenic purpura (ITP). Cystoscopy revealed irregular surface of bladder mucosa. On suspicion of bladder cancer, we performed transurethral resection of bladder tumor (TURBT). The pathological examination showed polypoid cyst, and we diagnosed hemorrhagic cystitis. Two months after the operation, gross hematuria was observed again. Although we administered choreitogoshimotsuto and then saireito, both were ineffective. Then we administered kamikihito, considering the findings of deficiency of ki (qi) and ketsu (blood) in Kampo diagnosis and the underlying disease ITP. One month after administering kamikihito, gross hematuria disappeared, urinary sediment test showed RBC 1-4/HPF. After one year of follow-up, bladder tumor was suspected by cystoscopy, but the pathological result of the second TUR-BT was inflammatory change. Since then, kamikihito was continued during the 44-month observation period, and no gross hematuria was observed.

Research Advance in Treatment of Thrombotic Thrombocytopenic Purpura --Review / 中国实验血液学杂志

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy, in which a severe deficiency of von Willebrand factor lyase results in thrombocytopenic clots that block blood vessels and eventually lead to terminal organ failure. Therapeutic plasma exchange is the cornerstone of TTP treatment which can greatly improves the survival rate of the patients. With the further exploration to the pathophysiological mechanism of TTP, other alternative therapies, new immunosuppressive agents, targeted antagonists, gene therapy and other emerging means gradually emerge, which are expected to further reduce the mortality and recurrence rate of the patients. In this review, the new developments in TTP treatment were summarized briefly.

The Progress in Research in Hereditary Thrombotic Thrombocytopenic Purpura in Children / 罕见病研究

Hereditary thrombotic thrombocytopenic purpura (hTTP) in children is a rare but severe and fatal thrombotic microangiopathy. The etiology of the disease is the persistent severe deficiency of the enzyme ADAMTS13 gene mutation, resulting in microangiopathic hemolytic anemia, thrombocytopenia, neuropsychiatric symptoms, fever, and renal involvement. Different from adults, children with hTTP present earlier onset of the disease and are more likely to develop long-term complications in brain and kidney, so that the need for preventive replacement therapy is more urgent. This article reviews the research progress of hTTP in children.

Evaluation of Sysmex XN-3000 for Detection of Schistocyte / 中国实验血液学杂志

OBJECTIVE@#Compared with the method of optical microscopy, to evaluate the accuracy of fragmented red cells(FRC) detection by Sysmex XN-3000.@*METHODS@#A total of 111 samples were collected from patients diagnosed as thrombotic thrombocytopenic purpura, autoimmune disease, hematological disease, malignant tumor and health examination in our hospital from June 2019 to February 2021, including 74 cases in the case group and 37 cases in the healthy control group. All samples were detected by optical microscope and Sysmex XN-3000, respectively. ROC was used to evaluate the detection ability of Sysmex XN-3000 for schistocyte. Bland-Altman method was used to evaluate the consistency of the results of the two methods for detection of schistocyte, and Pearson correlation analysis was conducted for the difference of the results.@*RESULTS@#The area under the ROC curve was 0.890(95% CI: 0.828-0.952, P<0.01). Sysmex XN-3000 count did not quantitatively agree with schistocyte counts by microscopy in the case group(mean of difference:-1.53, 95% limits of agreement: -8.78~5.72). There was a weak positive correlation between platelet count and the difference of analyzer and microscopic results (r=0.32,P<0.05).@*CONCLUSION@#Sysmex XN-3000 can be used as a reference for qualitative determination of schistocyte. However, the sensitivity of Sysmex XN-3000 should be improved. It is still necessary to combine with manual microscopy. The quantitative results are not reliable now and cannot be used as a reference for monitoring the results of schistocyte in clinical patients after treatment.

Reference range for ADAMTS13 antigen, activity and anti-ADAMTS13 antibody in the healthy adult Singapore population

INTRODUCTION@#ADAMTS13 (a disintegrin-like and metalloproteinase with a thrombospondin Type 1 motif, member 13) plays a fundamental role in the regulation of haemostasis and thrombosis. Its deficiency leads to an accumulation of ultra-large von Willebrand multimers, inducing spontaneous platelet aggregation, thrombosis in the microvasculature, and thrombotic thrombocytopenic purpura (TTP), a condition with 90% mortality when left untreated. Prompt quantification of ADAMTS13 antigen, activity and autoantibody plays a crucial role in the diagnosis and management of TTP and can help differentiate it from other thrombotic microangiopathies (TMAs). Reference ranges for ADAMTS13 are generally derived from Caucasian patients. Given that polymorphism in the ADAMTS13 gene can be associated with variable ADAMTS13 levels, we aimed to establish the first reference range in Singapore and provide a crucial laboratory test for institutions here and elsewhere.@*METHODS@#150 healthy voluntary donors (75 men, 75 women) aged 21-60 years, with an ethnic mix mirroring Singapore's population profile, were recruited. ADAMTS13 antigen, activity and autoantibody levels were measured using the fluorescence resonance energy transfer-vWF73 and enzyme-linked immunosorbent assay methodologies.@*RESULTS@#Levels (activity 0.65-1.79 IU/mL, antigen 0.36-1.17 IU/mL, autoantibody 1.4-12.5 U/mL) were not statistically different between the genders and various age groups.@*CONCLUSION@#TTP and TMAs are encountered in a wide range of specialties. The availability of new assays in Singapore will aid clinicians in the timely management of these conditions. Standardising reference ranges established for Singapore against World Health Organization standards allows harmonisation of measurements between laboratories and for future research collaborations.