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Authors
Abstract(s)
Introdução: Este relatório surge no âmbito do estágio curricular pertencente ao plano
de estudos do mestrado em Bioquímica pela Universidade da Beira Interior. Este estágio
foi realizado durante o período de 26 de setembro de 2022 a 31 de maio de 2023, nas
secções de hematologia, microbiologia e imunoquímica, no Serviço de Patologia Clínica
(SPC) do Centro Hospitalar Universitário Cova da Beira (CHUCB), Este relatório está
dividido em dois capítulos, um em que é descrito todo o trabalho de rotina dos
laboratórios das secções mencionadas acima, correspondente ao capítulo A, e o capítulo
B possui um trabalho científico de investigação desenvolvido durante o período de
estágio, com o título A importância do teste de mistura na deteção do anticoagulante
lúpico no diagnóstico da Síndrome Anti-fosfolípido. A síndrome anti-fosfolípido (SAF) é
uma doença autoimune sistémica, caracterizada por trombose arterial, venosa ou de
pequenos vasos e/ou morbidade gestacional, acompanhada pela presença de anticorpos
anti-fosfolípidos (AAF) persistentes como anticoagulante lúpico (AL), anticorpo
anticardiolipina (aCL) IgG e IgM e anticorpo anti-ß2-glicoproteína I (ß2-GPI) IgG e IgM.
De acordo com os critérios do Comité Científico e de Padronização (SSC), Subcomité de
Anticoagulante Lúpico/Anticorpos Dependentes de fosfolipídios da Sociedade
Internacional de Trombose e Hemostasia (ISTH), a pesquisa do AL é realizada em três
etapas, rastreio (screening), mistura e confirmatório.
Objetivos: A investigação teve como objetivo avaliar o desempenho do teste de mistura
na deteção ou exclusão do AL, em amostras de doentes com teste screening positivo e
estabelecer uma possível orientação para a implementação deste teste na deteção do AL
na rotina do laboratório.
Material e métodos: O estudo envolveu 40 doentes dos vários Serviços do CHUCB.
Foi colhido sangue venoso para um tubo de citrato de sódio 0,109 mol/L 9:1, que foi
centrifugado duas vezes a 3000 rpm por 10 minutos à temperatura ambiente, para
obtenção de plasma pobre em plaquetas. Todos os reagentes utilizados foram da
Instrumentation Laboratory (IL) da Werfen incluindo os controlos e os testes dRVVT
screen e confirm e SCT screen e confirm, para ensaios de coagulometria no equipamento
ACLTOP750.
Resultados: Através do teste SCT screening, foi detetado o AL em 45% dos
participantes e 50% continuaram positivos após a realização do teste de mistura. O que
revelou uma moderada concordância, kappa=0,524, (P=0,000), mostrando que K é
estatisticamente significativo. Com o teste dRVVT screening foi possível detetar o AL em
80% participantes, pelos quais somente 40,6% permaneceram positivos após o teste de
mistura e os outros 59,4% corrigiram para valores normais. Isto, revelou uma baixa concordância entre estes dois testes, com um valor de Kappa=0,215 (P=0,028),
mostrando uma significância estatística.
Conclusão: Os níveis de concordância dos testes de screening após os testes de mistura,
em muitos casos excluíram a presença do anticoagulante e podem indicar uma
interpretação diferente do que poderia conduzir ao diagnóstico do AL Logo, de acordo
com as recomendações SSC-ISTH, é possível propor um novo algoritmo a ser aplicado
no Serviço de Patologia Clínica, incluindo os testes de mistura, na deteção do AL.
Introduction: This report is a result of the curricular internship belonging to the study plan of the master's degree in Biochemistry at the University of Beira Interior. This internship was carried out during the period from September 26, 2022 to May 31, 2023, in the hematology, microbiology and immunochemistry sections, at the Serviço de Patologia Clínica (SPC) of the Centro Hospitalar Universitário Cova da Beira (CHUCB). This report is divided into two chapters, one in which all the routine work of the laboratories in the sections mentioned above is described, corresponding to chapter A, and chapter B has scientific research work developed during the internship period, with the title The importance of the mixture test in the detection of lupus anticoagulant in the diagnosis of Anti-phospholipid Syndrome. Anti-phospholipid syndrome (APS) is a systemic autoimmune disease, characterized by arterial, venous or small vessel thrombosis and/or gestational morbidity, accompanied by the presence of persistent anti-phospholipid antibodies (APA) as a lupus anticoagulant (LA), anticardiolipin (aCL) IgG and IgM antibody and anti-ß2-glycoprotein I (ß2-GPI) IgG and IgM antibody. According to the criteria of the Scientific and Standardization Committee (SSC), Lupus Anticoagulant/Phospholipid-Dependent Antibodies Subcommittee of the International Society on Thrombosis and Haemostasis (ISTH), LA research is performed in three stages, screening, mixing and confirmatory. Objectives: The investigation aimed to evaluate the performance of the mixture test in the detection or exclusion of AL, in samples from patients with a positive screening test and to establish a possible orientation for the implementation of this test in the detection of AL in the laboratory routine. Material and methods: The study involved 40 patients from the various CHUCB services. Venous blood was collected into a 0.109 mol/L 9:1 sodium citrate tube, which was centrifuged twice at 000 rpm for 10 minutes at room temperature, to obtain plateletpoor plasma. All reagents used were from Werfen's Instrumentation Laboratory (IL), including the dRVVT screen and confirm and SCT screen and confirm controls and tests, for coagulometry tests on the ACLTOP750 equipment. Results: Through the SCT screening test, LA was detected in 45% of the participants and 50% remained positive after performing the mixture test. Which revealed a moderate agreement, kappa=0.524, (P=0.000), showing that K is statistically significant. With the dRVVT screening test, it was possible to detect AL in 80% of the participants, whereby only 40.6% remained positive after the mixture test and the other 59.4% corrected for normal values. This revealed a low concordance between these two tests, with a Kappa value=0.215 (P=0.028), showing a statistical significance. Conclusion: The concordance levels of the screening tests after the mixing tests, in many cases excluded the presence of anticoagulant and may indicate a different interpretation of what could lead to the diagnosis of AL. Therefore, according to the SSCISTH recommendations, it is possible to propose a new algorithm to be applied in the Clinical Pathology Service, including mixing tests, in the detection of LA.
Introduction: This report is a result of the curricular internship belonging to the study plan of the master's degree in Biochemistry at the University of Beira Interior. This internship was carried out during the period from September 26, 2022 to May 31, 2023, in the hematology, microbiology and immunochemistry sections, at the Serviço de Patologia Clínica (SPC) of the Centro Hospitalar Universitário Cova da Beira (CHUCB). This report is divided into two chapters, one in which all the routine work of the laboratories in the sections mentioned above is described, corresponding to chapter A, and chapter B has scientific research work developed during the internship period, with the title The importance of the mixture test in the detection of lupus anticoagulant in the diagnosis of Anti-phospholipid Syndrome. Anti-phospholipid syndrome (APS) is a systemic autoimmune disease, characterized by arterial, venous or small vessel thrombosis and/or gestational morbidity, accompanied by the presence of persistent anti-phospholipid antibodies (APA) as a lupus anticoagulant (LA), anticardiolipin (aCL) IgG and IgM antibody and anti-ß2-glycoprotein I (ß2-GPI) IgG and IgM antibody. According to the criteria of the Scientific and Standardization Committee (SSC), Lupus Anticoagulant/Phospholipid-Dependent Antibodies Subcommittee of the International Society on Thrombosis and Haemostasis (ISTH), LA research is performed in three stages, screening, mixing and confirmatory. Objectives: The investigation aimed to evaluate the performance of the mixture test in the detection or exclusion of AL, in samples from patients with a positive screening test and to establish a possible orientation for the implementation of this test in the detection of AL in the laboratory routine. Material and methods: The study involved 40 patients from the various CHUCB services. Venous blood was collected into a 0.109 mol/L 9:1 sodium citrate tube, which was centrifuged twice at 000 rpm for 10 minutes at room temperature, to obtain plateletpoor plasma. All reagents used were from Werfen's Instrumentation Laboratory (IL), including the dRVVT screen and confirm and SCT screen and confirm controls and tests, for coagulometry tests on the ACLTOP750 equipment. Results: Through the SCT screening test, LA was detected in 45% of the participants and 50% remained positive after performing the mixture test. Which revealed a moderate agreement, kappa=0.524, (P=0.000), showing that K is statistically significant. With the dRVVT screening test, it was possible to detect AL in 80% of the participants, whereby only 40.6% remained positive after the mixture test and the other 59.4% corrected for normal values. This revealed a low concordance between these two tests, with a Kappa value=0.215 (P=0.028), showing a statistical significance. Conclusion: The concordance levels of the screening tests after the mixing tests, in many cases excluded the presence of anticoagulant and may indicate a different interpretation of what could lead to the diagnosis of AL. Therefore, according to the SSCISTH recommendations, it is possible to propose a new algorithm to be applied in the Clinical Pathology Service, including mixing tests, in the detection of LA.
Description
Keywords
Anticoagulante Lúpico Síndrome Anti-Fosfolípido Teste de
Mistura