The aim of this study was to check the effect of Triton X-100 on various, commonly used haematolo... more The aim of this study was to check the effect of Triton X-100 on various, commonly used haematology test parameters. Anonymised blood samples were treated with 10 µL of 10% Triton X-100 per 1 mL of blood. Treated and untreated samples were tested in parallel for blood film morphology, complete blood counts (CBCs), flow cytometry, blood grouping and antibody screens. Samples were also taken in 3.2% citrate tubes for coagulation test analyses. Statistical differences were noted in all CBC parameters apart from the mean cell volume, eosinophil and basophil counts. Platelet counts were significantly different with an apparent rise after the addition of Triton X-100. Samples were noted to have a high red cell fragmentation index. Immunological platelet counting methods using flow cytometry and fluorescent methods showed no significant differences and gave reliable results. Neither flow cytometry for T-cell subsets nor blood grouping/antibody screens were affected by Triton X-100. However, coagulation samples were severely haemolysed prohibiting analysis. We have demonstrated that the addition of Triton X-100 to haematology blood samples impacts mainly on platelet counts and coagulation studies due to haemolysis. The platelet count is spuriously raised probably due to the presence of red cell fragments. The latter can be circumvented by the use of immunological platelet counting technology.
Low Molecular Weight Heparin (LMWH) has been recently introduced in the Catheterisation Suite at ... more Low Molecular Weight Heparin (LMWH) has been recently introduced in the Catheterisation Suite at Mater Dei Hospital (MDH) for Urgent Percutaneous Coronary Interventions (PCI). Due to its infancy locally, this audit was set up, so as to assess how LMWH was administered, comparing results to the European Society of Cardiology (ESC) recommendations and Summary of Product Characteristics (SPC).
Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting ... more Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting factor concentrate type is scant. It was the aim of this study to report inhibitor development in non-severe haemophilia patients enrolled in the European Haemophilia Safety Surveillance (EUHASS) study. Inhibitors are reported quarterly and total treated patients annually. Incidence rates and 95% confidence intervals (95% CI) were calculated according to diagnosis and concentrate used. Between 1-10-2008 and 31-12-2012, 68 centres reported on 7,969 patients with non-severe haemophilia A and 1,863 patients with non-severe haemophilia B. For haemophilia A, 37 inhibitors occurred in 8,622 treatment years, resulting in an inhibitor rate of 0.43/100 treatment years (95% CI 0.30-0.59). Inhibitors occurred at a median age of 35 years, after a median of 38 exposure days (EDs; P25-P75: 20-80); with 72% occurring within the first 50 EDs. In haemophilia B, one inhibitor was detected in 2,149 treatme...
Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis
Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relati... more Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relative contraindication for the use of prothrombin complex concentrates (PCCs). We discuss a patient who developed an anaphylactic reaction to PCC on a background of selective IgA deficiency with anti-IgA antibodies and with a history of anaphylactic reaction to other blood products. Further analysis of PCCs revealed the presence of variable quantities of immunoglobulins of all classes, including IgA. Although the summary of product characteristics for PCCs from various manufacturers does not list IgA deficiency with anti-IgA antibodies as an absolute or relative contraindication, our findings suggest that PCCs are not devoid of IgA and great caution must be exercised with their use in patients with IgA deficiency with anti-IgA antibodies and with previously documented reactions.
Inhibitor development represents the most serious side effect of haemophilia treatment. Any diffe... more Inhibitor development represents the most serious side effect of haemophilia treatment. Any difference in risk of inhibitor formation depending on the product used might be of clinical relevance. It was this study's objective to assess inhibitor development according to clotting factor concentrate in severe haemophilia A and B. The European Haemophilia Safety Surveillance (EUHASS) was set up as a study monitoring adverse events overall and according to concentrate. Since October 2008, inhibitors were reported at least quarterly. Number of treated patients was reported annually, specifying the number of patients completing 50 exposure days (Previously Untreated Patients, PUPs) without inhibitor development. Cumulative incidence, incidence rates and 95 % confidence intervals (CI) were calculated. Data from October 1, 2008 to December 31, 2012 were analysed for 68 centres that validated their data. Inhibitors developed in 108/417 (26 %; CI 22-30 %) PUPs with severe haemophilia A an...
Low molecular weight heparin (LMWH) given to inhibit coagulation and reduce the risk of thrombosi... more Low molecular weight heparin (LMWH) given to inhibit coagulation and reduce the risk of thrombosis, is typically monitored by anti-Xa assay. However, anti-Xa levels may not necessarily provide an accurate measure of coagulation inhibition. Moreover, pregnancy is associated with hypercoagulability, which may compromise the efficacy of LMWH. We looked at the association between anti-Xa levels and parameters of thrombin generation assay [TGA; area under the curve (AUC), peak height (PH) and time to peak (ttP)] using samples from 41 pregnant women receiving LMWH and 40 normal pregnant women controls. TGA results confirmed the physiological hypercoagulability of normal pregnancy (mean normalised values: AUC 119%; PH 157%; ttP 72%). Although anti-Xa measures correlated with all three TGA parameters, this group correlation masked significant inter-individual variability, demonstrated by the R(2) value or coefficient of determination. Anti-Xa levels contributed to 74% of variation in AUC va...
Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relati... more Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relative contraindication for the use of prothrombin complex concentrates (PCCs). We discuss a patient who developed an anaphylactic reaction to PCC on a background of selective IgA deficiency with anti-IgA antibodies and with a history of anaphylactic reaction to other blood products. Further analysis of PCCs revealed the presence of variable quantities of immunoglobulins of all classes, including IgA. Although the summary of product characteristics for PCCs from various manufacturers does not list IgA deficiency with anti-IgA antibodies as an absolute or relative contraindication, our findings suggest that PCCs are not devoid of IgA and great caution must be exercised with their use in patients with IgA deficiency with anti-IgA antibodies and with previously documented reactions.
Adoption of international normalized ratio (INR) to harmonize prothrombin time has greatly improv... more Adoption of international normalized ratio (INR) to harmonize prothrombin time has greatly improved the safety and effectiveness of vitamin K antagonists (VKA) oral anticoagulant therapy. INR is also a major laboratory variable in calculating the widely used Model for End-Stage Liver Disease (MELD) score for liver transplant organ prioritization. However, since the conventional INR (INRVKA) is calibrated specifically for VKA patients, its interlaboratory variation has a significant impact on the accuracy of MELD score. Though still requiring further clinical validation in large numbers of waitlisted patients, the alternative liver INR calibrated by using plasma from liver disease patients instead of VKA patients may harmonize the differences and thus more suitable for MELD score calculation. The objective of this article is to review the history of INR, MELD score, and liver INR, and discuss the challenges and solutions of liver INR implementation.
Accurate platelet counts (PC) are necessary in order to follow recommendations for prophylactic p... more Accurate platelet counts (PC) are necessary in order to follow recommendations for prophylactic platelet transfusion. We carried out a study comparing the standard way of counting platelets using a routine analyser and compared it with PC determined by flow cytometry (FC) and haemostatic data obtained with thromboelastography (TEG). The study was carried out on 24 patients with haematological malignancies, all given one adult dose of platelets. The PC was determined before and after transfusion using an automated blood cell counter and FC. Citrated, "native" whole blood TEG was carried out before and after platelet transfusion to assess global haemostasis. No bleeding was observed in any of the subjects. Thirty-one assessments were performed in the 24 patients. The mean pre-transfusion PC were 9.8 and 13×10(9)/L with the automated counter and FC, respectively with a difference of 3.7 (p=0.0011). Excellent correlation was observed between the two counts (r=0.89; p<0.0001...
ABSTRACT Patients with liver disease whether acute or chronic suffer from a coagulopathy and this... more ABSTRACT Patients with liver disease whether acute or chronic suffer from a coagulopathy and this, in the past, has been associated with a bleeding phenotype. Laboratory investigations typically reveal a high Prothrombin Time (PT)/International Normalised Ratio (INR) and Activated Partial Thromboplastin Time (APTT) and sometimes a low fibrinogen level. The high PT was noted since the inception of the test by Armand Quick(1). It was later realised that this test was exquisitely sensitive to low factor VII levels. The PT/INR became established tests to monitor coumarin anticoagulant therapy and since high PT/INR values correlate with an increased risk of bleeding in patients on similar drugs, the raised PT in patients with liver disease was considered to indicate a state of &#39;autoanticoagulation&#39;. This notion has been challenged over the past decade. This article is protected by copyright. All rights reserved.
The aim of this study was to check the effect of Triton X-100 on various, commonly used haematolo... more The aim of this study was to check the effect of Triton X-100 on various, commonly used haematology test parameters. Anonymised blood samples were treated with 10 µL of 10% Triton X-100 per 1 mL of blood. Treated and untreated samples were tested in parallel for blood film morphology, complete blood counts (CBCs), flow cytometry, blood grouping and antibody screens. Samples were also taken in 3.2% citrate tubes for coagulation test analyses. Statistical differences were noted in all CBC parameters apart from the mean cell volume, eosinophil and basophil counts. Platelet counts were significantly different with an apparent rise after the addition of Triton X-100. Samples were noted to have a high red cell fragmentation index. Immunological platelet counting methods using flow cytometry and fluorescent methods showed no significant differences and gave reliable results. Neither flow cytometry for T-cell subsets nor blood grouping/antibody screens were affected by Triton X-100. However, coagulation samples were severely haemolysed prohibiting analysis. We have demonstrated that the addition of Triton X-100 to haematology blood samples impacts mainly on platelet counts and coagulation studies due to haemolysis. The platelet count is spuriously raised probably due to the presence of red cell fragments. The latter can be circumvented by the use of immunological platelet counting technology.
Low Molecular Weight Heparin (LMWH) has been recently introduced in the Catheterisation Suite at ... more Low Molecular Weight Heparin (LMWH) has been recently introduced in the Catheterisation Suite at Mater Dei Hospital (MDH) for Urgent Percutaneous Coronary Interventions (PCI). Due to its infancy locally, this audit was set up, so as to assess how LMWH was administered, comparing results to the European Society of Cardiology (ESC) recommendations and Summary of Product Characteristics (SPC).
Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting ... more Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting factor concentrate type is scant. It was the aim of this study to report inhibitor development in non-severe haemophilia patients enrolled in the European Haemophilia Safety Surveillance (EUHASS) study. Inhibitors are reported quarterly and total treated patients annually. Incidence rates and 95% confidence intervals (95% CI) were calculated according to diagnosis and concentrate used. Between 1-10-2008 and 31-12-2012, 68 centres reported on 7,969 patients with non-severe haemophilia A and 1,863 patients with non-severe haemophilia B. For haemophilia A, 37 inhibitors occurred in 8,622 treatment years, resulting in an inhibitor rate of 0.43/100 treatment years (95% CI 0.30-0.59). Inhibitors occurred at a median age of 35 years, after a median of 38 exposure days (EDs; P25-P75: 20-80); with 72% occurring within the first 50 EDs. In haemophilia B, one inhibitor was detected in 2,149 treatme...
Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis
Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relati... more Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relative contraindication for the use of prothrombin complex concentrates (PCCs). We discuss a patient who developed an anaphylactic reaction to PCC on a background of selective IgA deficiency with anti-IgA antibodies and with a history of anaphylactic reaction to other blood products. Further analysis of PCCs revealed the presence of variable quantities of immunoglobulins of all classes, including IgA. Although the summary of product characteristics for PCCs from various manufacturers does not list IgA deficiency with anti-IgA antibodies as an absolute or relative contraindication, our findings suggest that PCCs are not devoid of IgA and great caution must be exercised with their use in patients with IgA deficiency with anti-IgA antibodies and with previously documented reactions.
Inhibitor development represents the most serious side effect of haemophilia treatment. Any diffe... more Inhibitor development represents the most serious side effect of haemophilia treatment. Any difference in risk of inhibitor formation depending on the product used might be of clinical relevance. It was this study's objective to assess inhibitor development according to clotting factor concentrate in severe haemophilia A and B. The European Haemophilia Safety Surveillance (EUHASS) was set up as a study monitoring adverse events overall and according to concentrate. Since October 2008, inhibitors were reported at least quarterly. Number of treated patients was reported annually, specifying the number of patients completing 50 exposure days (Previously Untreated Patients, PUPs) without inhibitor development. Cumulative incidence, incidence rates and 95 % confidence intervals (CI) were calculated. Data from October 1, 2008 to December 31, 2012 were analysed for 68 centres that validated their data. Inhibitors developed in 108/417 (26 %; CI 22-30 %) PUPs with severe haemophilia A an...
Low molecular weight heparin (LMWH) given to inhibit coagulation and reduce the risk of thrombosi... more Low molecular weight heparin (LMWH) given to inhibit coagulation and reduce the risk of thrombosis, is typically monitored by anti-Xa assay. However, anti-Xa levels may not necessarily provide an accurate measure of coagulation inhibition. Moreover, pregnancy is associated with hypercoagulability, which may compromise the efficacy of LMWH. We looked at the association between anti-Xa levels and parameters of thrombin generation assay [TGA; area under the curve (AUC), peak height (PH) and time to peak (ttP)] using samples from 41 pregnant women receiving LMWH and 40 normal pregnant women controls. TGA results confirmed the physiological hypercoagulability of normal pregnancy (mean normalised values: AUC 119%; PH 157%; ttP 72%). Although anti-Xa measures correlated with all three TGA parameters, this group correlation masked significant inter-individual variability, demonstrated by the R(2) value or coefficient of determination. Anti-Xa levels contributed to 74% of variation in AUC va...
Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relati... more Immunoglobulin A (IgA) deficiency with anti-IgA antibodies is not listed as an absolute or relative contraindication for the use of prothrombin complex concentrates (PCCs). We discuss a patient who developed an anaphylactic reaction to PCC on a background of selective IgA deficiency with anti-IgA antibodies and with a history of anaphylactic reaction to other blood products. Further analysis of PCCs revealed the presence of variable quantities of immunoglobulins of all classes, including IgA. Although the summary of product characteristics for PCCs from various manufacturers does not list IgA deficiency with anti-IgA antibodies as an absolute or relative contraindication, our findings suggest that PCCs are not devoid of IgA and great caution must be exercised with their use in patients with IgA deficiency with anti-IgA antibodies and with previously documented reactions.
Adoption of international normalized ratio (INR) to harmonize prothrombin time has greatly improv... more Adoption of international normalized ratio (INR) to harmonize prothrombin time has greatly improved the safety and effectiveness of vitamin K antagonists (VKA) oral anticoagulant therapy. INR is also a major laboratory variable in calculating the widely used Model for End-Stage Liver Disease (MELD) score for liver transplant organ prioritization. However, since the conventional INR (INRVKA) is calibrated specifically for VKA patients, its interlaboratory variation has a significant impact on the accuracy of MELD score. Though still requiring further clinical validation in large numbers of waitlisted patients, the alternative liver INR calibrated by using plasma from liver disease patients instead of VKA patients may harmonize the differences and thus more suitable for MELD score calculation. The objective of this article is to review the history of INR, MELD score, and liver INR, and discuss the challenges and solutions of liver INR implementation.
Accurate platelet counts (PC) are necessary in order to follow recommendations for prophylactic p... more Accurate platelet counts (PC) are necessary in order to follow recommendations for prophylactic platelet transfusion. We carried out a study comparing the standard way of counting platelets using a routine analyser and compared it with PC determined by flow cytometry (FC) and haemostatic data obtained with thromboelastography (TEG). The study was carried out on 24 patients with haematological malignancies, all given one adult dose of platelets. The PC was determined before and after transfusion using an automated blood cell counter and FC. Citrated, "native" whole blood TEG was carried out before and after platelet transfusion to assess global haemostasis. No bleeding was observed in any of the subjects. Thirty-one assessments were performed in the 24 patients. The mean pre-transfusion PC were 9.8 and 13×10(9)/L with the automated counter and FC, respectively with a difference of 3.7 (p=0.0011). Excellent correlation was observed between the two counts (r=0.89; p<0.0001...
ABSTRACT Patients with liver disease whether acute or chronic suffer from a coagulopathy and this... more ABSTRACT Patients with liver disease whether acute or chronic suffer from a coagulopathy and this, in the past, has been associated with a bleeding phenotype. Laboratory investigations typically reveal a high Prothrombin Time (PT)/International Normalised Ratio (INR) and Activated Partial Thromboplastin Time (APTT) and sometimes a low fibrinogen level. The high PT was noted since the inception of the test by Armand Quick(1). It was later realised that this test was exquisitely sensitive to low factor VII levels. The PT/INR became established tests to monitor coumarin anticoagulant therapy and since high PT/INR values correlate with an increased risk of bleeding in patients on similar drugs, the raised PT in patients with liver disease was considered to indicate a state of &#39;autoanticoagulation&#39;. This notion has been challenged over the past decade. This article is protected by copyright. All rights reserved.
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