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: Factor XIII (FXIII) levels may decrease because of surgical consumption. Acquired FXIII deficiency could be a cause of postoperative hemorrhage usually underdiagnosed in clinical practice. To determine the diagnosis confirmation rate of acquired FXIII deficiency in postsurgical patients with clinical suspicion and to compare the characteristics and evolution of patients with or without FXIII deficiency. We performed a retrospective cohort study, which included 49 inpatients who were attended at our university hospital from 2014 to 2018 with suspicion of acquired FXIII deficiency because of disproportionate postoperative hemorrhage. FXIIIA levels less than 50% was considered a deficiency. Persistence of bleeding for more than 48 h, drop in hematocrit points, red blood cells transfused units, hemoglobin levels 12-36 h after bleeding, and time elapsed from the procedure to the bleeding were assessed as outcome variables. Logistic regression was employed for both univariate and multivariate analyses. Of the 49 patients included, 27(55%) had FXIII deficiency, with a median level of 34% [interquartile range (IQR) 19-42]. Abdominal surgery was the most common [n = 21 (43%)]. All patients had routine coagulation tests within the hemostatic range. FXIII deficiency was associated with a drop of more than 4 points in hematocrit [OR 59.69 (95% CI 4.71-755.30)], red blood transfused units >2 [OR 45.38 (95% CI 3.48-590.65)], and delayed bleeding >36 h after surgery [OR 100.90 (95% CI 3.78-2695.40)]. Plasma-derived FXIII concentrate was administered to eight patients with life-threatening bleeding with resolution within 24 h. Only one deficient patient died from bleeding. FXIII levels were measured 15 days after diagnosis or more in 20 out of 27 deficient patients, with normal results. Acquired FXIII deficiency may be a frequent underdiagnosed entity that should be considered when high-volume and delayed postoperative hemorrhage is present in patients with hemostatic routine coagulation test results.

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BACKGROUND: Rivaroxaban oral anticoagulant does not need laboratory monitoring, but in some situations plasma level measurement is useful. The objective of this paper was to verify analytical performance and compare two rivaroxaban calibrated anti Xa assays/coagulometer systems with specific or other branch calibrators. METHODS: In 59 samples drawn at trough or peak from patients taking rivaroxaban, plasma levels were measured by HemosIL Liquid anti Xa in ACLTOP 300/500, and STA liquid Anti Xa in TCoag Destiny Plus. HemosIL and STA rivaroxaban calibrators and controls were used. CLSI guideline procedures EP15A3 for precision and trueness, EP6 for linearity, and EP9 for methods comparison were used. RESULTS: Coefficient of variation within run and total precision (CVR and CVWL respectively) of plasmatic rivaroxaban were < 4.2 and < 4.85% and BIAS < 7.4 and < 6.5%, for HemosIL-ACL TOP and STA-Destiny systems, respectively. Linearity verification 8 - 525 ng/mL a Deming regression for methods comparison presented R 0.963, 0.968 and 0.982, with a mean CV 13.3% when using different systems and calibrations. CONCLUSIONS: The analytical performance of plasma rivaroxaban was acceptable in both systems, and results from reagent/coagulometer systems are comparable even when calibrating with different branch material.

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Dabigatran etexilate (direct thrombin inhibitor) is effective in preventing embolic stroke in patients with atrial fibrillation. It does not require laboratory control, but given the high renal elimination, its measurement in plasma is important in renal failure. The objectives of the study were to verify the analytical quality of the diluted thrombin time assay for measurement of dabigatran plasma concentration (cc), correlate cc with classic coagulation assays, prothrombin time (PT) and activated partial thromboplastin time (APTT), and evaluate them according to the creatinine clearance (CLCr). Forty plasma samples of patients (34 consecutive and 6 suspected of drug accumulation) receiving dabigatran at 150 (n = 19) or 110 (n = 21) mg/12 hours were collected. Blood samples were drawn at 10-14 hours of the last intake. Dabigatran concentration was determined by diluted thrombin time (HemosIl DTI, Instrumentation Laboratory (IL). PT and APTT (IL) were performed on two fotooptical coagulometers, ACL TOP 300 and 500 (IL). DTI presented intra-assay coefficient of variation < 5.4% and inter-assay < 6%, linearity range 0-493 ng/ml. Patients' cc: median 83 (4-945) ng/ml. Individuals with CLCr in the lowest tertile (22.6-46.1 ml/min) showed significantly higher median cc: 308 (49-945), compared to the average 72 (12-190) and highest tertile, 60 (4-118) ng/ml. Correlation between cc and APTT or PT were moderate, r2 = 0.59 and -0.66, p < 0.0001, respectively. DTI test allowed us to quantify plasma dabigatran levels, both in patients with normal or altered renal function, representing a useful tool in clinical situations such as renal failure, pre surgery or emergencies.

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El dabigatrán etexilato (inhibidor directo de trombina) es eficaz en la prevención tromboembólica en pacientes con fibrilación auricular. No requiere control rutinario de laboratorio, pero dada su eliminación renal, sería importante medirlo ante el deterioro de la función renal. Los objetivos del trabajo fueron verificar la calidad analítica del ensayo tiempo de trombina diluido para medición de la concentración plasmática (cc) de dabigatrán, correlacionar las cc con las pruebas básicas de coagulación tiempo de protrombina (TP) y tiempo de tromboplastina parcial activada (APTT) y evaluarlas de acuerdo al clearance de creatinina (CLCr). Se utilizaron muestras de plasma de 40 pacientes que recibían dabigatrán 150 (n = 19) o 110 (n = 21) mg/12 horas, colectadas 10-14 horas después de la última toma. Los ensayos de trombina diluida HemosIL DTI para la medición de dabigatrán, TP y APTT (IL), fueron realizados en coagulómetros fotoópticos ACL TOP 300 y 500 (IL). El DTI presentó coeficiente de variación intraensayo < 5.4% e interensayo < 6.0%, rango de linealidad 0-493 ng/ml; cc medidas en pacientes: mediana 83 (4-945) ng/ml. Individuos con CLCr en tercil inferior (< 46.1 ml/min) presentaron cc significativamente más elevadas, 308 (49-945), que los de tercilos medio, 72 (12-190), y superior, 60 (4-118) ng/ml. Las correlaciones cc vs. APTT o TP fueron moderadas, r2 = 0.59, -0.66, p < 0.0001, respectivamente. La prueba ensayada permitió cuantificar el nivel de dabigatrán plasmático tanto en pacientes con función renal normal como deteriorada, representando una herramienta útil en situaciones clínicas como deterioro de la función renal, pre cirugía o emergencias.

Dabigatran etexilate (direct thrombin inhibitor) is effective in preventing embolic stroke in patients with atrial fibrillation. It does not require laboratory control, but given the high renal elimination, its measurement in plasma is important in renal failure. The objectives of the study were to verify the analytical quality of the diluted thrombin time assay for measurement of dabigatran plasma concentration (cc), correlate cc with classic coagulation assays, prothrombin time (PT) and activated partial thromboplastin time (APTT), and evaluate them according to the creatinine clearance (CLCr). Forty plasma samples of patients (34 consecutive and 6 suspected of drug accumulation) receiving dabigatran at 150 (n = 19) or 110 (n = 21) mg/12 hours were collected. Blood samples were drawn at 10-14 hours of the last intake. Dabigatran concentration was determined by diluted thrombin time (HemosIl DTI, Instrumentation Laboratory (IL). PT and APTT (IL) were performed on two fotooptical coagulometers, ACL TOP 300 and 500 (IL). DTI presented intra-assay coefficient of variation < 5.4% and inter-assay < 6%, linearity range 0-493 ng/ml. Patients´ cc: median 83 (4-945) ng/ml. Individuals with CLCr in the lowest tertile (22.6-46.1 ml/min) showed significantly higher median cc: 308 (49-945), compared to the average 72 (12-190) and highest tertile, 60 (4-118) ng/ml. Correlation between cc and APTT or PT were moderate, r2 = 0.59 and -0.66, p < 0.0001, respectively. DTI test allowed us to quantify plasma dabigatran levels, both in patients with normal or altered renal function, representing a useful tool in clinical situations such as renal failure, pre surgery or emergencies.

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BACKGROUND: Laboratory determination of fibrinogen/fibrin degradation product (FDP) levels is important as a hyperfibrinolytic state marker. The aim of the study was to verify the analytical performance of an automated immunoturbidimetric assay (AIMT) for FDP and its comparison to a latex agglutination semiquantitative (SLAT) test. METHODS: Total precision and accuracy was calculated following the EP 15-A2 protocol at two levels of controls. The protocol EP6 was performed for linearity. For semi-quantitative methods comparison, 71 consecutive samples were used. Concordance between methods results in term of positive and negative, and in categories, from <10 to > 160 µg/mL, was calculated through Cohen kappa coefficient (). RESULTS: Total CV%: low control (10.8 µg/mL) 8.0 and 3.7 vs. 4.8 and high control (31.3 µg/mL) 2.7 and 3.8 vs. 3.6, for coagulometer ACL TOP 500 and 300 vs. manufacturer claimed, respectively. Linearity between 0 and 125 µg/mL showed polynomial fit analysis applicable. When correlating AIMT to SLAT, a good concordance was observed:  of results expressed as positive-negative = 79.5% with 90.1% of agreement (p < 0.001), of results expressed as categories = 72.2% (p < 0.001) with 80.3% concordance. CONCLUSIONS: AIMT presented good analytical performance, and the concordance with SLAT by comparison of patients' samples results was also good. The implementation of IMMT in the clinical laboratory is suitable and reliable.

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