Near-fatal cocaine intoxication in an infant with thrombotic microangiopathy associated with multiple organ failure / Intoxicação grave por cocaína em criança com microangiopatia trombótica associada à falência múltipla de órgãos

ABSTRACT Objective: To report a pediatric case of drug-induced thrombotic microangiopathy caused by cocaine Case description: We report a nine-month-old patient who developed thrombotic microangiopathies after extreme cocaine intoxication, multiple organ dysfunction syndrome with hemodynamic dysfunction, anuric renal failure, liver failure, encephalopathy, and myocardial injury, corresponding phenotypically to thrombocytopenia-associated multiple organ failure. The patient received continuous venous hemofiltration and therapeutic plasma exchange, recovering satisfactorily. She was discharged after 30 days of hospitalization under the guidance of the childcare service, and was healthy after one year of follow-up. Toxicological samples confirmed high levels of cocaine and derivatives in blood, urine and hair. Comments: To our knowledge, this is the first reported pediatric case. There are particularities of cocaine intoxication pathophysiology that can trigger thrombotic microangiopathies because of vasoconstriction, direct endothelial injury, platelet activation, and increasing von Willebrand factor and fibrinogen levels. All of which results in a prothrombotic state, inflammatory dysregulation, and microvascular thrombi. The increasing use of cocaine, especially among young adults, puts children at high risk of toxicity, either by passive unintentional exposure, or abuse due to the increased availability in homes.

RESUMO Objetivo: Relatar um caso pediátrico de microangiopatia trombótica induzida por drogas causada por cocaína Descrição do caso: Relatamos uma paciente de nove meses de idade que desenvolveu microangiopatia trombótica após intoxicação extrema por cocaína, síndrome de disfunção de múltiplos órgãos com disfunção hemodinâmica, insuficiência renal anúrica, insuficiência hepática, encefalopatia e lesão miocárdica, correspondendo fenotipicamente à falência múltipla de órgãos associada à trombocitopenia. A paciente recebeu hemofiltração venosa contínua e plasmaférese terapêutica, recuperando-se satisfatoriamente. Recebeu alta após 30 dias de internação sob orientação do serviço de puericultura e estava saudável após um ano de seguimento. Amostras toxicológicas confirmaram altos níveis de cocaína e derivados no sangue, urina e cabelos. Comentários: Até onde sabemos, este é o primeiro caso pediátrico relatado. Existem particularidades da fisiopatologia da intoxicação por cocaína que podem desencadear a microangiopatia trombótica devido à vasoconstrição, lesão endotelial direta, ativação plaquetária e aumento do fator de von Willebrand e dos níveis de fibrinogênio. Tudo isso resulta em um estado pró-trombótico, desregulação inflamatória e trombos microvasculares. O uso crescente de cocaína, principalmente entre adultos jovens, coloca as crianças em alto risco de toxicidade, seja por exposição passiva não intencional ou abuso devido à maior disponibilidade nas residências.

Púrpura trombótica trombocitopénica en pediatría. Reporte de un caso / Thrombotic thrombocytopenic purpura in pediatrics. A case report

La púrpura trombótica trombocitopénica es una entidad poco frecuente en pediatría, pero de alta mortalidad sin tratamiento adecuado y oportuno. Se caracteriza por presentar anemia hemolítica microangiopática asociada a signos y síntomas neurológicos, cardíacos, abdominales y menos frecuentemente renales; puede estar acompañada de fiebre. En niños, el diagnóstico se basa en los hallazgos clínicos y de laboratorio. La actividad de ADAMTS13 <10 % apoya, pero no confirma el diagnóstico y, dada la gravedad de la patología, el resultado no debe retrasar el inicio del tratamiento. Se presenta una paciente de 15 años, previamente sana, con signos neurológicos asociados a anemia hemolítica y trombocitopenia. Durante su internación, se arribó al diagnóstico de púrpura trombótica trombocitopénica adquirida.

Thrombotic thrombocytopenic purpura is a rare disease in pediatrics, but it has a high mortality if not managed in an adequate and timely manner. It is characterized by microangiopathic hemolytic anemia associated with neurological, cardiac, abdominal, and less frequently, renal signs and symptoms; it may be accompanied by fever. In children, diagnosis is based on clinical and laboratory findings. ADAMTS13 activity < 10% supports the diagnosis but does not confirm it and, given its severity, the result should not delay treatment initiation. Here we describe the case of a previously healthy 15-year-old female patient with neurological signs associated with hemolytic anemia and thrombocytopenia. During hospitalization, she was diagnosed with acquired thrombotic thrombocytopenic purpura.

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.

Application Value of Plasma vWF and ADAMTS-13 in Evaluating Postoprative Vascular Endothelial Injury and Prognosis in Children with VSD / 中国实验血液学杂志

OBJECTIVE@#To dynamically observe the levels and activities of von Willebrand factor (vWF) and ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) in plasma of children with congenital ventricular septal defect (VSD) during perioperative period, and explore the value of plasma vWF antigen (vWF:Ag) and ADAMTS-13 activity (ADAMTS-13: AC) in evaluating vascular endothelial injury and prognosis in children with VSD.@*METHODS@#In this cross-sectional study, a total of 74 children with VSD who underwent surgical treatment in TEDA International Cardiovascular Hospital from September 2018 to March 2019 were enrolled in the observation group. Among them, there were 28 cases of pure VSD, 32 cases of VSD combined with pulmonary hypertension, and 14 cases of VSD combined with valvular heart disease. 31 healthy children who underwent physical examination in Tianjin Children's Hospital during the same period were collected as the control group. The biochemical indexes of the children at admission were recorded. Peripheral plasma was collected at admission, postsurgery day 0 and day 1, respectively, and the levels of vWF activity (vWF:AC), vWF:Ag, ADAMTS-13 antigen (ADAMTS-13:Ag) and ADAMTS-13:AC were detected.@*RESULTS@#The level of plasma vWF:Ag and vWF:AC in the observation group before surgery were significantly lower than those in the control group (P<0.001), and increased continuously, on postsurgery day 0 and day 1 (P<0.001). The level of ADAMTS-13:Ag in the observation group before surgery was significantly higher than that in the control group (P<0.001), which decreased significantly on postsurgery day 0 (P<0.001), and increased significantly on postsurgery day 1 compared with postsurgery day 0 (P=0.033). The level of ADAMTS-13:AC in the observation group before surgery was significantly lower than that in the control group (P=0.015), which decreased significantly on postsurgery day 0 (P=0.037), and increased on postsurgery day 1, but the difference was not statistically significant (P=0.051). The changes of vWF and ADAMTS-13 in the three subgroups were basically similar to the observation group. vWF: Ag/ADAMTS-13: AC ratio on postsurgery day 0 and day 1 had high diagnostic value in vascular endothelial injury (AUC=0.80, P<0.001; AUC=0.93, P<0.001). Preoperative vWF and ADAMTS-13 levels, and related baseline indicators were not correlated with postoperative infection, bleeding, thrombosis,etc.@*CONCLUSION@#Preoperative vWF: Ag, vWF: AC and ADAMTS-13: AC levels in children with VSD are low, while the level of ADAMTS-13: Ag is high. After surgery, the levels of vWF: Ag and vWF: AC are increased and the level of ADAMTS-13: Ag is decreased. The postoperative vWF: Ag/ADAMTS-13: AC ratio shows high diagnostic value in evaluating vascular endothelial injury. There is no correlation between preoperative vWF and ADAMTS-13 levels with perioperative clinical events.

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.

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.

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.

Hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli in a renal transplant recipient case report / Síndrome hemolítico-urêmica causada por Escherichia coli produtora de toxina Shiga em um relato de caso de receptor de transplante renal

Abstract Thrombotic microangiopathies are disorders characterized by nonimmune microangiopathic hemolytic anemia, thrombocytopenia, and multi-systemic failure. They are classified as thrombotic thrombocytopenic purpura, atypical hemolytic-uremic syndrome, and typical hemolytic uremic syndrome. The latter is associated with intestinal infections by Shiga toxin-producing bacteria. Typical hemolytic uremic syndrome in adults is an extremely rare condition, characterized by high morbidity and mortality. It has been seldom described in solid organ transplant recipients. Here is presented the case of a kidney transplant recipient who had typical hemolytic uremic syndrome with multisystem commitment, refractory to management and with a fatal outcome.

Resumo Microangiopatias trombóticas são distúrbios caracterizados por anemia hemolítica microangiopática não imune, trombocitopenia e insuficiência multissistêmica. Elas são classificadas como púrpura trombocitopênica trombótica, síndrome hemolítico-urêmica atípica e síndrome urêmica hemolítica típica. Essa última está associada a infecções intestinais por bactérias produtoras da toxina Shiga. A síndrome hemolítica urêmica típica em adultos é uma condição extremamente rara, caracterizada por alta morbimortalidade. Esta é raramente descrita em receptores de transplantes de órgãos sólidos. Apresentamos aqui o caso de um receptor de transplante renal que apresentava síndrome hemolítico-urêmica típica com comprometimento multissistêmico, refratário ao tratamento, e com desfecho fatal.

Manejo oportuno de púrpura trombocitopénica trombótica en paciente con lupus eritematoso sistémico: reporte de caso / Timely management of thrombotic thrombocytopenic purpura in a patient with systemic lupus erythematosus: case report

Introducción: La púrpura trombocitopénica trombótica puede presentarse en menos del 2 por ciento de los pacientes con lupus eritematoso sistémico. Esta asociación implica un aumento de la mortalidad y un periodo de remisión más prolongado. Objetivo: Se presenta el caso de paciente peruana que desarrolló esta asociación y presentó complicaciones relacionadas con shock séptico. Caso clínico: Paciente femenina, con antecedente de púrpura trombocitopénica inmunológica y lupus eritematoso sistémico, acudió a emergencia por presentar palidez cutánea generalizada, petequias en miembros inferiores y hematuria. Posteriormente, su estado de salud se complicó con un shock séptico y deterioro del nivel de conciencia. Por todo esto, es referida a un hospital de mayor complejidad y hace su ingreso a la unidad de cuidados intensivos. La clínica y los exámenes de laboratorio revelaron hallazgos compatibles con púrpura trombocitopénica trombótica (anemia grave, plaquetopenia, esquistositosis) y lupus eritematoso sistémico activo grave. Antes de ser referida, recibió pulsos de metilprednisona y prednisona. Ya en unidad de cuidados intensivos, se cambió a soporte ventilatorio y tratamiento antibiótico. Con el diagnóstico presuntivo de púrpura trombocitopénica trombótica, asociada a lupus eritematoso sistémico activo grave, se inició tratamiento oportuno con plasmaféresis, corticoterapia y ciclofosfamida. La paciente recuperó los niveles plaquetarios y el nivel óptimo de conciencia. Actualmente acude a controles. Conclusiones: La púrpura trombocitopénica trombótica es una emergencia hematológica con alta mortalidad en ausencia de tratamiento. Su reconocimiento oportuno, sin dosificación de la proteína ADAMTS13, en esta asociación poco frecuente con lupus eritematoso sistémico es importante en el buen pronóstico del paciente(AU)

Introduction: Thrombotic thrombocytopenic purpura may occur in less than 2 percent of patients with systemic lupus erythematosus. This association implies an increase in mortality and a longer remission period. Objective: We present the case of a Peruvian woman who developed this association, and complicating herself with septic shock. Clinical case: A female patient, with a history of immunological thrombocytopenic purpura and systemic lupus erythematosus, comes to the emergency room due to generalized skin pallor, lower limb petechiae and hematuria. Subsequently, her state of health gets complicated with a septic shock and deterioration of the level of consciousness. For all of this, she was referred to a hospital of greater complexity and makes admission to an intensive care unit. Clinical and laboratory tests revealed findings compatible with thrombotic thrombocytopenic purpura (severe anemia, platelet disease, schistositosis) and severe active systemic lupus erythematosus. Before being referred, she received pulses of methylprednisone and prednisone. When already in the intensive care unit, it was changed to ventilatory support andantibiotic treatment. With the presumptive diagnosis of thrombotic thrombocytopenic purpura, associated with severe active systemic lupus erythematosus, a timely treatment was initiated with plasmapheresis, corticosteroids and cyclophosphamide. The patient recovered platelet levels and optimal level of consciousness. She is currently going to controls. Conclusions: Thrombotic thrombocytopenic purpura is a hematological emergency with high mortality in the absence of treatment. Its timely recognition, without dosing of ADAMTS13 protein, in this rare association with systemic lupus erythematosus is important in the good prognosis of the patient(AU)

Expression of ADAMTS13 and PCNA in the placentas of gestational diabetic mothers / Expresión de ADAMTS13 y PCNA en las placentas de madres diabéticas gestacionales

SUMMARY: GDM is linked with overexpression of inflammatory cytokines and increased oxidative stress, leading to endothelial dysfunction and vascular disorder. Weaimed to examine the expression of ADAMTS13 and PCNA in the placentas of gestational diabetes mellitus (GDM) patients to investigate the effects of hypoxia, induced by GDM, on proliferation and extracellular matrix formation in the maternal and fetal placenta cells. A total of 60 placentas were collected from pregnant women admitted to the obstetrics clinic. Thirty of them were diagnosed with GDM, and 30 of them were diagnosed with non-GDM patients. Samples were fixed in 10 % formaldehyde, after routine follow-up, embedded in paraffin wax. Sections of 5 µm were cut stained with Mayer Hematoxylin-Eosin, examined under a light microscope. Sections for immunohistochemical analysis were cut and processed for antigen retrievalin citrate solution. Sections were incubated with ADAMTS13 and PCNA primary antibodies, counterstained with hematoxylin, and evaluate under a light microscope. In histopathological examination, the non-diabetic placentas showed that decidua cells in the maternal region were polygonal with oval nuclei and organized in groups. In the GDM group, there were pyknosis and apoptotic changes in decidua cell nuclei. Vacuolar areas were observed in large cavities in maternal connective tissue. Inflammation and dilatation with congestion were observed in the blood vessels of the villus. In the GDM group, positive ADAMTS13 expression was observed in the decidua cells vascular endothelial cells, and surrounding connective tissue fibroblast cells. In the GDM group, a significant increase in PCNA expression was observed in decidua cells, connective tissue cells and endothelial cells. Functional changes in ADAMTS13 proteases and PCNA were thought to induce maternal and fetal complications by stimulating extracellular matrix development.

RESUMEN: La diabetes gestacional está relacionada con la sobreexpresión de citocinas inflamatorias y aumento del estrés oxidativo, lo que lleva a una disfunción endotelial y un trastorno vascular. Nuestro objetivo fue examinar la expresión de ADAMTS13 y PCNA en las placentas con diabetes mellitus gestacional (DMG) para investigar los efectos de la hipoxia inducida por DMG sobre la proliferación y formación de matriz extracelular en células placentarias maternas y fetales. Se recolectaron un total de 60 placentas de mujeres embarazadas ingresadas a la consulta de obstetricia. Treinta de ellas fueron diagnosticadas con DMG y 30 diagnosticadas sin DMG. Las muestras se fijaron en formaldehído al 10 %, y luego de un seguimiento de rutina, fueron embebidas en parafina. Se cortaron secciones de 5 µm teñidas con hematoxilina-eosina de Mayer, las que fueron examinadas bajo un microscopio óptico. Se cortaron y procesaron las secciones para el análisis inmunohistoquímico para la recuperación de antígeno en solución de citrato. Las secciones se incubaron con anticuerpos primarios ADAMTS13 y PCNA, se contratiñeron con hematoxilina y se evalua- ron con un microscopio óptico. En el examen histopatológico, las placentas no diabéticas mostraron que las células de la decidua en la región materna eran poligonales con núcleos ovalados y organizadas en grupos. En el grupo de DMG, se observó picnosis y cambios apoptóticos en los núcleos de las células de la decidua. Se observaron áreas vacuolares en el tejido conectivo materno. En los vasos sanguíneos de las vellosidades se observó inflamación y dilatación con congestión. En el grupo de DMG, se observó expresión positiva de ADAMTS13 en las células de la decidua, en las células endoteliales vasculares y en los fibroblastos del tejido conectivo circundante. En el grupo de DMG se observó un aumento significativo de la expresión de PCNA en células de la decidua, células de tejido conectivo y en las células endoteliales. Se considera que los cambios funcionales en las proteasas ADAMTS13 y PCNA inducen a complicaciones maternas y fetales al estimular el desarrollo de la matriz extracelular.

Clinical analysis of 59 patients with thrombotic thrombocytopenic purpura / 中华急诊医学杂志

Objective To investigate the clinical features,diagnosis,treatment and prognosis of 59 patients with thrombotic thrombocytopenic purpura (TTP),therefore to improve the ability of diagnosis and treatment.Methods The clinical data of 59 patients with TTP admitted to Peking University People's Hospital from January 2004 to October 2018 were retrospectively analyzed.All the patients were clinically diagnosed,fulfilled the triad syndrome,or quinary syndrome.Laboratory data included complete blood count,blood biochemistry,immtmology,hemolysis;some patients tested the activity of ADAMTS13.The differences between groups were compared according to the prognosis.Results Among the 59 patients with TTP,21 were male and 38 were female,with an average age of 46.8 years.Fifty-five patients had the triad syndrome and 46 patients had the quinary syndrome.The platelet count and hemoglobin decreased,the percentage of erythrocyte fragmented increased,and the value or the activity of ADAMTS13 was decreased significantly.PLASMIC scores of 57 patients were between 6 and 7.All 59 patients were treated with glucocorticoid,41 patients received plasma exchange (PEX),and 28 patients survived;18 patients did not received PEX,and only 6 patients survived.There was a significant difference of the survival between the two groups (P＜0.05).Six patients were treated with rituximab and four patients survived.Conclusion The PLASMIC score can predict the activity of ADAMTS 13 well.PEX can significantly improve the survival rate of patients with TTP.

Grupos sanguíneos y su relación con los niveles plasmáticos del Factor de von Willebrand / Blood groups and their relationship with plasma levels of von Willebrand Factor

Resumen Introducción: El tipo de grupo sanguíneo entre otros factores, influye en los niveles plasmáticos del Factor de von Willebrand (FvW), su actividad biológica podría incidir en el desarrollo de eventos trombóticos y hemorrágicos. Objetivo: Describir las características y los mecanismos de reacciones postrasduccionales del grupo sanguíneo que permiten la variación en la concentración plasmática del FvW. Materiales y métodos: Revisión teórico descriptiva de tipo documental. Las bases de datos consultadas fueron Medline, Lilacs, ScienceDirect, Scopus, SciELO, Proquest, Ovid y Pubmed. Como criterio de selección se incluyeron artículos en idioma inglés y español a partir del año 2010 y algunos anteriores como referente histórico. Resultados: Se describieron los principales mecanismos e investigaciones que evidencian la influencia del tipo de grupo sanguíneo ABO en los niveles plasmáticos del FvW, así como la estructura y función de dicha proteína. Conclusiones: Las concentraciones plasmáticas del FvW pueden depender del tipo de grupo sanguíneo, la edad, sexo, embarazo, ciclo menstrual, variación de proteínas y factores bioquímicos e inmunológicos. Se podría tener en cuenta el tipo de grupo sanguíneo de los pacientes como un posible factor predictor a futuro de complicaciones clínicas tanto trombóticas como hemorrágicas.

Abstract Introduction: The type of blood group among other factors influences the plasma levels of von Willebrand Factor (FvW) and its biological activity could influence the development of thrombotic and hemorrhagic events. Objective: To describe the characteristics and mechanisms of post-translational reactions of the blood group that generate variation in the plasma concentration of FvW. Materials and methods: A descriptive theoretical review of documentary type. The databases consulted were Medline, Lilacs, ScienceDirect, Scopus, SciELO, Proquest, Ovid and Pubmed. As a selection criterion, articles in English and Spanish were included beginning in 2010 and some previous ones as historical reference. Results: The main mechanisms and investigations that show the influence of the ABO blood group type on the plasma levels of FvW, as well as the structure and function of this protein were described. Conclusions: FvW plasma concentrations may depend on the type of blood group, age, sex, pregnancy, menstrual cycle, protein variation and biochemical and immunological factors. The type of blood group of patients could be considered as a possible future predictor of both thrombotic and hemorrhagic clinical complications.

Plasmic score applicability for the diagnosis of thrombotic microangiopathy associated with ADAMTS13-acquired deficiency in a developing country

ABSTRACT Background: Thrombotic thrombocytopenic purpura (TTP) is a potentially fatal disease that requires early diagnosis and treatment that can be made possible by applying the PLASMIC score. This study aims to evaluate this score applicability for patients with suspected TTP in a developing country. Methods: This was a retrospective study performed at a tertiary hospital in the northeastern region of Brazil. Patients were analyzed in two groups: ADAMTS13 activity <10% and activity >10%. Patients were stratified according to the PLASMIC score, and the level of agreement between the PLASMIC score and the ADAMTS13 activity was evaluated. Results: Eight patients with thrombotic microangiopathy were included. Four patients had ADAMTS13 activity <10%, all with a PLASMIC score =6. The other four had ADAMTS13 activity >10%, all with a score <6. Based on a score =6 for presumptive diagnosis of TTP, we attained a 100% diagnostic accuracy in our sample. The PLASMIC score was also able to accurately predict response to plasma exchange and the risk of long-term unfavorable outcomes. Conclusions: The reproducibility of the PLASMIC score was quite satisfactory in our sample. It accurately discriminates between patients who had ADAMTS13 deficiency and those with normal enzyme activity, precluding the need for specific laboratory evaluation, which is not always available. This score can be useful for an early diagnosis and indicates which patients will benefit from the treatment in developing countries.

Prognostic utility of ADAMTS13 activity for the atypical hemolytic uremic syndrome (aHUS) and comparison of complement serology between aHUS and thrombotic thrombocytopenic purpura

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) involves dysregulation of the complement system, but whether this also occurs in thrombotic thrombocytopenic purpura (TTP) remains unclear. Although these conditions are difficult to differentiate clinically, TTP can be distinguished by low (<10%) ADAMTS13 activity. The aim was to identify the differences in complement activation products between TTP and aHUS and investigate ADAMTS13 activity as a prognostic factor in aHUS. METHODS: We analyzed patients with thrombotic microangiopathy diagnosed as TTP (N=48) or aHUS (N=50), selected from a Korean registry (N=551). Complement activation products in the plasma samples collected from the patients prior to treatment and in 40 healthy controls were measured by ELISA. RESULTS: The levels of generalized (C3a), alternate (factor Bb), and terminal (C5a and C5b-9) markers were significantly higher (all P<0.01) in the patients than in the healthy controls. Only the factor Bb levels significantly differed (P=0.008) between the two disease groups. In aHUS patients, high normal ADAMTS13 activity (≥77%) was associated with improved treatment response (OR, 6.769; 95% CI, 1.605–28.542; P=0.005), remission (OR, 6.000; 95% CI, 1.693–21.262; P=0.004), exacerbation (OR, 0.242; 95% CI, 0.064–0.916; P=0.031), and disease-associated mortality rates (OR, 0.155; 95% CI, 0.029–0.813; P=0.017). CONCLUSION: These data suggest that complement biomarkers, except factor Bb, are similarly activated in TTP and aHUS patients, and ADAMTS13 activity can predict the treatment response and outcome in aHUS patients.

Clinical characteristics and outcomes of thrombotic microangiopathy in Malaysia

BACKGROUND: Thrombotic microangiopathy (TMA) with non-deficient ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif 13) outcome is unknown hence the survival analysis correlating with ADAMTS-13 activity is conducted in Malaysia. METHODS: This was a retrospective epidemiological study involving all cases of TMA from 2012–2016. RESULTS: We evaluated 243 patients with a median age of 34.2 years; 57.6% were female. Majority of the patients were Malay (62.5%), followed by Chinese (23.5%) and Indian (8.6%). The proportion of patients with thrombotic thrombocytopenic purpura (TTP) was 20.9%, 72.2% of which were acquired while 27.8% were congenital. Patients with ADAMTS-13 activity ≥5% had a four-fold higher odds of mortality compared to those with ADAMTS-13 activity <5% (odds ratio: 4.133, P=0.0425). The mortality rate was 22.6% (N=55). Most cases had secondary etiologies (42.5%), followed by acquired TTP (16.6%), atypical hemolytic uremic syndrome (HUS) or HUS (12.8%) and congenital TTP (6.4%). Patients with secondary TMA had inferior overall survival (P=0.0387). The secondary causes comprised systemic lupus erythematosus (30%), infection (29%), pregnancy (10%), transplant (8%), malignancy (6%), and drugs (3%). Transplant-associated TMA had the worst OS (P=0.0016) among the secondary causes. Plasma exchange, methylprednisolone and intravenous immunoglobulin were recorded as first-line treatments in 162 patients, while rituximab, bortezomib, vincristine, azathioprine, cyclophosphamide, cyclosporine, and tacrolimus were described in 78 patients as second-line treatment. CONCLUSION: This study showed that TMA without ADAMTS-13 deficiency yielded inferior outcomes compared to TMA with severeADAMTS-13 deficiency, although this difference was not statistically significant.

A Case of Thrombotic Thrombocytopenic Purpura with Exacerbation after Incomplete Remission of Therapeutic Plasma Exchange / 대한수혈학회지

Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder with a mortality rate of over 90% without prompt treatment. It is caused by congenital, idiopathic, or secondary diseases; idiopathic TTP is mainly associated with deficiency of ADAMTS13, a von Willebrand factor cleaving protease or ADAMTS13 inhibitors. The long-term survival rate of TTP has improved since the introduction of therapeutic plasma exchange (TPE), and the therapeutic aims have also been established. However, deciding on the end-point and appropriate treatment method requires careful assessment of clinical conditions of patients. The present study reports a case of a 33-year-old male patient with reduced ADAMTS13 activity and ADAMTS13 inhibitor, who developed symptoms after an early termination of TPE with improved symptoms, which finally improved with retreatment and additionally corticosteroid. We report our case with relevant literature review on TPE in TTP with this case.

Effect of Vitamin D Status on Von Willebrand Factor and ADAMTS13 in Diabetic Patients on Chronic Hemodialysis

Von Willebrand factor (vWF) is a glycoprotein with a crucial role in the formation of platelet thrombi, and ADAMTS13 is the main enzyme responsible for vWF cleavage. Both are important in the relationship between diabetic nephropathy, hypercoagulability, and cardiovascular disease. This study evaluated a potential relationship between vitamin D (vitD) levels, vWF, ADAMTS13 activity, and inflammation in diabetic patients on chronic hemodialysis (HD). Blood samples from 52 diabetic patients on chronic HD were obtained to determine vitD levels, vWF, and ADAMTS13 activity, and inflammatory markers. HD patients were grouped according to 25-hydroxyvitamin D [25(OH) VitD]25 nmol/L (n=36). vWF antigen and vWF activity were elevated in both groups, with an average of 214.3±82.6% and 175.8±72.6%, respectively. Average ADAMTS13 activity was within the normal range in both groups. Blood samples from the vitD <25 nmol/L group showed a positive correlation between c-reactive protein (CRP) and vWF levels (P=0.023; r=0.564; 95% confidence interval=0.095-0.828), with a negative correlation between HbA1c and 25(OH) VitD (P=0.015; r=-0.337; 95% confidence interval=-0.337-0.19). Diabetic patients on chronic HD had elevated vWF levels and activity with no significant change in ADAMTS13 activity. The correlation between CRP and vWF levels in the 25(OH) VitD<25 nmol/L group suggests inflammatory-related endothelial dysfunction in these patients.

Twenty-one patients with thrombotic thrombocytopenic purpura:a clinical study / 中华急诊医学杂志

Objective To investigate clinical features, outcomes and laboratory findings of thrombotic thrombocytopenic purpura (TTP).Methods Patients with TTP admitted between April 2006 and January 2013 were identified by a retrospective review of records.Totally 21 patients were available,15 females and 6 males,with a median age of 46 years (ranged 18-66).The diagnostic criteria were defined by:(1)thrombocytopenia (<100 ×9 L-1)without other identifiable causes;(2)a negative Coombs'test and hemolytic anemia with schistocytes on the peripheral blood smear;and only those patients meeting the criteria for TTP,both on clinical presentation and their clinical course,were included in this study. Exclusion criteria were:(1)patients discharged or dead within 24 hours after admission;(2)patients treated with plasma exchange therapy in other hospitals;(3)medical data were incomplete;(4)cannot be followed up;and (5 )other causes of thrombotic microangiopathies.General condition of patients,etiology, clinical features,treatment and prognosis were analyzed by using the SPSS 20.0 software.P value of <0.05 was considered as significant.Results Hemolytic anemia and thrombocytopenia appeared in all of the patients. Twelve patients (57.2%) had the classical pentad manifestations of TTP (fever, thrombocytopenia,microangiopathic hemolytic anemia,symptoms of nervous system,renal injury),seven patients (33.3%)had tetrad of TTP clinical manifestations (thrombocytopenia,microangiopathic hemolytic anemia,symptoms of nervous system,fever or renal injury),and only two patients showed the triad manifestations of TTP (thrombocytopenia, microangiopathic hemolytic anemia, symptoms of nervous system).In our studies,seven patients accepted plasmapheresis,and five of them (71.4%)achieved remission.Conclusions TTP progresses quickly.Plasmapheresis is still the treatment of choice for TTP patients.Etiological treatment can help to control the conditions of patients with TTP.

Plasmatic ADAMTS-13 metalloprotease and von Willebrand factor in children with cyanotic congenital heart disease

Changes in plasma von Willebrand factor concentration (VWF:Ag) and ADAMTS-13 activity (the metalloprotease that cleaves VWF physiologically) have been reported in several cardiovascular disorders with prognostic implications. We therefore determined the level of these proteins in the plasma of children with cyanotic congenital heart disease (CCHD) undergoing surgical treatment. Forty-eight children were enrolled (age 0.83 to 7.58 years). Measurements were performed at baseline and 48 h after surgery. ELISA, collagen-binding assays and Western blotting were used to estimate antigenic and biological activities, and proteolysis of VWF multimers. Preoperatively, VWF:Ag and ADAMTS-13 activity were decreased (65 and 71% of normal levels considered as 113 (105-129) U/dL and 91 ± 24% respectively, P < 0.003) and correlated (r = 0.39, P = 0.0064). High molecular weight VWF multimers were not related, suggesting an interaction of VWF with cell membranes, followed by proteolytic cleavage. A low preoperative ADAMTS-13 activity, a longer activated partial thromboplastin time and the need for cardiopulmonary bypass correlated with postoperative bleeding (P < 0.05). Postoperatively, ADAMTS-13 activity increased but less extensively than VWF:Ag (respectively, 2.23 and 2.83 times baseline, P < 0.0001), resulting in an increased VWF:Ag/ADAMTS-13 activity ratio (1.20 to 1.54, respectively, pre- and postoperative median values, P = 0.0029). ADAMTS-13 consumption was further confirmed by decreased ADAMTS-13 antigenic concentration (0.91 ± 0.30 to 0.70 ± 0.25 µg/mL, P < 0.0001) and persistent proteolysis of VWF multimers. We conclude that, in pediatric CCHD, changes in circulating ADAMTS-13 suggest enzyme consumption, associated with abnormal structure and function of VWF.

Decreased plasma ADAMTS-13 activity as a predictor of postoperative bleeding in cyanotic congenital heart disease

OBJECTIVE: To analyze the preoperative plasma antigenic concentration and activity of von Willebrand factor and its main cleaving protease ADAMTS-13 in pediatric patients with cyanotic congenital heart disease undergoing surgical treatment and investigate possible correlations with postoperative bleeding. METHODS: Plasma antigenic concentrations (von Willebrand factor:Ag and ADAMTS-13:Ag) were measured using enzyme-linked immunoassays. Collagen-binding assays were developed to measure biological activities (von Willebrand factor:collagen binding and ADAMTS-13 activity). The multimeric structure of von Willebrand factor was analyzed using Western immunoblotting. Demographic, diagnostic, and general and specific laboratory data and surgery-related variables were subjected to univariate, bivariate, and multivariate analysis for the prediction of postoperative bleeding. RESULTS: Forty-eight patients were enrolled, with ages ranging from 9 months to 7.6 years (median 2.5 years). The plasma concentrations of von Willebrand factor:Ag and ADAMTS-13:Ag were decreased by 65 and 82%, respectively, in the patients compared with the controls (p<0.001). An increased density of low-molecular-weight fractions of von Willebrand factor, which are suggestive of proteolytic degradation (p = 0.0081), was associated with decreased ADAMTS-13 activity, which was likely due to ADAMTS-13 consumption (71% of controls, p = 0.0029) and decreased von Willebrand factor:collagen binding (76% of controls, p = 0.0004). Significant postoperative bleeding occurred in 13 patients. The preoperative ADAMTS-13 activity of <64.6% (mean level for the group), preoperative activated partial thromboplastin time, and the need for cardiopulmonary bypass were characterized as independent risk factors for postoperative bleeding, with respective hazard ratios of 22.35 (95% CI 1.69 to 294.79), 1.096 (95% CI 1.016 to 1.183), and 37.43 (95% ...