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Advisor(s)
Abstract(s)
A quantificação celular do Líquido Cefalorraquidiano (LCR) é uma metodologia com grande relevância nos serviços de Patologia Clínica, em especial na área de hematologia, nomeadamente em caso de doenças neuro-inflamatórias, hemorragias subaracnoideias e doenças hemato-oncológicas. Apesar dos inúmeros avanços tecnológicos dos contadores celulares automáticos, no Serviço de Patologia Clínica (SPC) do Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG) a contagem de células no LCR é atualmente realizada com hemocitómetro (câmara de Nageotte) e posteriormente, caso o número de células ultrapasse o valor de referência, procede-se à contagem diferencial de células utilizando técnicas de cito-centrifugação e coloração por May-Grünwald-Giemsa. Trata-se de um procedimento moroso e dependente da presença constante de profissionais altamente qualificados. Neste trabalho foi avaliada a possibilidade de automatizar a contagem de células no LCR, através de um estudo descritivo-comparativo, com o objetivo de validar e implementar o método. Assim comparou-se o método manual de contagem de células do LCR (método de referência) com o método automático do Alinity hq. Os dados obtidos foram tratados estatisticamente de modo a determinar a concordância entre os métodos e ainda a capacidade de o Alinity hq discriminar as amostras patológicas (≥ 5 leucócitos/µL) das normais (<5 leucócitos/µL). Utilizando o método de Bland-Altman, obteve-se para os leucócitos uma diferença média entre o método manual e o Alinity hq de – 2,0 leucócitos/µL e uma concordância (com intervalo de confiança de 95%) de [-30,18 a 26,18 leucócitos/µL]. Para os eritrócitos, a diferença média obtida foi de -106,36 eritrócitos/µL e a concordância (com intervalo de confiança de 95%) de [-934,64 a 721,96 eritrócitos/µL]. Apesar dos resultados obtidos abrangerem o conjunto de valores com interesse clínico, seria desejável obter-se mais resultados patológicos e assim aprofundar o estudo do desempenho do Alinity hq. A baixa concentração celular do LCR e os valores de aceitação clínica definidos para o método, não apoiam a implementação do Alinity hq na prática clínica.
ABSTRACT - Cell quantification in the Cerebrospinal fluid (CSF) is a method with great relevance in clinical pathology laboratories, especially in haematology, namely when neuroinflammatory, subarachnoid bleeding, and neoplastic pathologies are suspected. Despite the numerous technical improvements of the automatic haematology analysers, in the Clinical Pathology Department at the Portuguese Institute of Oncology in Lisbon, the CSF cell count is currently performed with a hemocytometer (Nageotte chamber). Subsequently, if the cell count is higher than the reference value, the differential count is accomplished through May-Grünwald-Giemsa staining. This is a time-consuming process that depends on the availability of skilled professionals. To assess the possibility of automating the CSF cell count, a comparative-descriptive study was conducted, to validate and implement the method. So, therefore, a comparison between the manual CSF cell count method (reference method) and the Alinity hq automatic analyser was performed. The collected data was statistically processed to assess the limits of agreement between both methods and the ability of Alinity hq to discriminate pathological samples (≥ 5 leucocytes/µL) from normal samples (< 5 leucocytes/µL). Using the Bland-Altman method, we obtained for leucocytes a mean difference between manual count and automatic count of – 2,0 leucocytes/µL and an agreement (with a confidence interval of 95%) of [-30,18 to 26,18 leucocytes/µL]. For the erythrocytes, we obtained a mean difference of -106,36 erythrocytes/µL and an agreement (with a confidence interval of 95%) of [-934,64 to 721,96 erythrocytes/µL]. Although the obtained results cover the range of values with clinical interest, we hoped to get more pathologic results and therefore improve the study of Alinity hq’s performance. The CSF's low cellular content and the clinically accepted reference values imposed for the method are a hinder to implementing the Alinity hq in clinical practice.
ABSTRACT - Cell quantification in the Cerebrospinal fluid (CSF) is a method with great relevance in clinical pathology laboratories, especially in haematology, namely when neuroinflammatory, subarachnoid bleeding, and neoplastic pathologies are suspected. Despite the numerous technical improvements of the automatic haematology analysers, in the Clinical Pathology Department at the Portuguese Institute of Oncology in Lisbon, the CSF cell count is currently performed with a hemocytometer (Nageotte chamber). Subsequently, if the cell count is higher than the reference value, the differential count is accomplished through May-Grünwald-Giemsa staining. This is a time-consuming process that depends on the availability of skilled professionals. To assess the possibility of automating the CSF cell count, a comparative-descriptive study was conducted, to validate and implement the method. So, therefore, a comparison between the manual CSF cell count method (reference method) and the Alinity hq automatic analyser was performed. The collected data was statistically processed to assess the limits of agreement between both methods and the ability of Alinity hq to discriminate pathological samples (≥ 5 leucocytes/µL) from normal samples (< 5 leucocytes/µL). Using the Bland-Altman method, we obtained for leucocytes a mean difference between manual count and automatic count of – 2,0 leucocytes/µL and an agreement (with a confidence interval of 95%) of [-30,18 to 26,18 leucocytes/µL]. For the erythrocytes, we obtained a mean difference of -106,36 erythrocytes/µL and an agreement (with a confidence interval of 95%) of [-934,64 to 721,96 erythrocytes/µL]. Although the obtained results cover the range of values with clinical interest, we hoped to get more pathologic results and therefore improve the study of Alinity hq’s performance. The CSF's low cellular content and the clinically accepted reference values imposed for the method are a hinder to implementing the Alinity hq in clinical practice.
Description
Mestrado em Tecnologias Clínico-Laboratoriais
Keywords
Líquido cefalorraquidiano Hemocitómetro Automatização Alinity hq Contagem diferencial de células Cerebrospinal fluid Haemocytometer Automation Cell differential count
Citation
Bragança FM. Quantificação celular no líquido cefalorraquidiano: estudo comparativo entre método manual e Alinity HQ [dissertation]. Lisboa: Escola Superior de Tecnologia da Saúde de Lisboa/Instituto Politécnico de Lisboa; 2023.
Publisher
Instituto Politécnico de Lisboa, Escola Superior de Tecnologia da Saúde de Lisboa