ABSTRACT
Rivaroxaban is an oral direct factor Xa inhibitor, therapeutically indicated in the treatment of thromboembolic diseases. As other new oral anticoagulants, routine monitoring of rivaroxaban is not necessary, but important in some clinical circumstances. In our study a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was validated to measure rivaroxaban plasmatic concentration. Our method used a simple sample preparation, protein precipitation, and a fast chromatographic run. It was developed a precise and accurate method, with a linear range from 2 to 500 ng/mL, and a lower limit of quantification of 4 pg on column. The new method was compared to a reference method (anti-factor Xa activity) and both presented a good correlation (r = 0.98, p < 0.001). In addition, we validated hemolytic, icteric or lipemic plasma samples for rivaroxaban measurement by HPLC-MS/MS without interferences. The chromogenic and HPLC-MS/MS methods were highly correlated and should be used as clinical tools for drug monitoring. The method was applied successfully in a group of 49 real-life patients, which allowed an accurate determination of rivaroxaban in peak and trough levels.
Subject(s)
Blood Coagulation Tests , Chromatography, High Pressure Liquid , Factor Xa Inhibitors/pharmacokinetics , Rivaroxaban/pharmacokinetics , Tandem Mass Spectrometry , Drug Monitoring , Factor Xa Inhibitors/therapeutic use , Humans , Reproducibility of Results , Rivaroxaban/therapeutic use , Sensitivity and SpecificityABSTRACT
OBJECTIVE:: To discuss the implementation of technical advances in laboratory diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria for validation of high-sensitivity flow cytometry protocols. METHODS:: A retrospective study based on analysis of laboratory data from 745 patient samples submitted to flow cytometry for diagnosis and/or monitoring of paroxysmal nocturnal hemoglobinuria. RESULTS:: Implementation of technical advances reduced test costs and improved flow cytometry resolution for paroxysmal nocturnal hemoglobinuria clone detection. CONCLUSION:: High-sensitivity flow cytometry allowed more sensitive determination of paroxysmal nocturnal hemoglobinuria clone type and size, particularly in samples with small clones. OBJETIVO:: Discutir as melhorias técnicas no diagnóstico e no acompanhamento laboratorial de hemoglobinúria paroxística noturna para a validação da técnica de citometria de fluxo de alta sensibilidade. MÉTODOS:: Estudo retrospectivo, que envolveu a análise de dados laboratoriais de 745 pacientes com hipótese diagnóstica e/ou acompanhamento de hemoglobinúria paroxística noturna por citometria de fluxo. RESULTADOS:: Os avanços técnicos não só reduziram o custo do ensaio, mas também melhoraram a identificação e a resolução da citometria de fluxo para a detecção de clone hemoglobinúria paroxística noturna. CONCLUSÃO:: A citometria de fluxo de alta sensibilidade possibilitou a identificação do tipo e do tamanho de clone de hemoglobinúria paroxística noturna, especialmente em amostras com pequeno clone.
Subject(s)
Flow Cytometry/methods , Hemoglobinuria, Paroxysmal/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/blood , Antigens, CD/blood , Child , Child, Preschool , Female , Flow Cytometry/economics , Flow Cytometry/instrumentation , Flow Cytometry/standards , Hemoglobinuria, Paroxysmal/blood , Humans , Infant , Middle Aged , Quality Improvement/economics , Retrospective Studies , Sensitivity and Specificity , Young AdultABSTRACT
ABSTRACT Objective: To discuss the implementation of technical advances in laboratory diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria for validation of high-sensitivity flow cytometry protocols. Methods: A retrospective study based on analysis of laboratory data from 745 patient samples submitted to flow cytometry for diagnosis and/or monitoring of paroxysmal nocturnal hemoglobinuria. Results: Implementation of technical advances reduced test costs and improved flow cytometry resolution for paroxysmal nocturnal hemoglobinuria clone detection. Conclusion: High-sensitivity flow cytometry allowed more sensitive determination of paroxysmal nocturnal hemoglobinuria clone type and size, particularly in samples with small clones.
RESUMO Objetivo: Discutir as melhorias técnicas no diagnóstico e no acompanhamento laboratorial de hemoglobinúria paroxística noturna para a validação da técnica de citometria de fluxo de alta sensibilidade. Métodos: Estudo retrospectivo, que envolveu a análise de dados laboratoriais de 745 pacientes com hipótese diagnóstica e/ou acompanhamento de hemoglobinúria paroxística noturna por citometria de fluxo. Resultados: Os avanços técnicos não só reduziram o custo do ensaio, mas também melhoraram a identificação e a resolução da citometria de fluxo para a detecção de clone hemoglobinúria paroxística noturna. Conclusão: A citometria de fluxo de alta sensibilidade possibilitou a identificação do tipo e do tamanho de clone de hemoglobinúria paroxística noturna, especialmente em amostras com pequeno clone.
