| 1. |
- Astermark, Jan, et al.
(författare)
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Blödarsjuka med HIV. Långsammare infektionsförlopp hos yngre och vid större förbrukning av faktorkoncentrat
- 1998
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Ingår i: Läkartidningen. - 0023-7205. ; 95:1, s. 48-50
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Tidskriftsartikel (refereegranskat)abstract
- HIV disease progression and the effect of replacement therapy with clotting factor concentrates (CFCs) were studied in 100 Swedish haemophiliacs, mean age at seroconversion 29 years (range, 4-72). On average 16 years after seroconversion, 67 per cent of the patients had CD4+ cell counts of < 200 x 10(6)/l, 50 per cent had developed AIDS, and 58 per cent had died. HIV disease progression was significantly slower in those aged less than 28 (median age) at seroconversion (P = 0.004). Moreover, mortality was inversely correlated to total annual CFC consumption after adjustment for age and HIV-related therapy, i.e., Pneumocystis carinii prophylaxis and antiretroviral drugs (P = 0.014), but unrelated to the purity of the CFCs used. After adjustment for age, annual CFC consumption and HIV-therapy, prophylactic replacement therapy was not associated with significantly better survival than on-demand treatment. It is concluded that in HIV-positive haemophiliacs replacement therapy may have a beneficial effect on the immune system, and that CFC purity and the regimen (prophylaxis vs on-demand) would seem to be factors of minor importance.
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| 2. |
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| 3. |
- Hillarp, Andreas, et al.
(författare)
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Effects of the oral, direct factor Xa inhibitor rivaroxaban on commonly used coagulation assays
- 2011
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Ingår i: JOURNAL OF THROMBOSIS AND HAEMOSTASIS. - : Blackwell Publishing. - 1538-7933 .- 1538-7836. ; 9:1, s. 133-139
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Rivaroxaban is an oral direct factor Xa inhibitor developed for prophylaxis and treatment of thromboembolic disorders. Laboratory monitoring is not necessary but the dose-dependent effects on common reagents and assay procedures are largely unknown. Objectives: To investigate the effect of rivaroxaban on commonly used coagulation assays. Materials and Methods: Rivaroxaban was added to plasma from healthy subjects in the concentration range 0-1000 mu g L-1 and analyzed using different reagents for activated partial thromboplastin time (APTT), prothrombin time (PT), antithrombin, fibrinogen and activated protein C (APC) resistance assays. Results: At an expected peak concentration of rivaroxaban in clinical use, the APTTs were almost invariably prolonged but at lower concentrations the effect was weak. The concentration needed to double the APTT varied between 389 +/- 106 and 617 +/- 149 mu g L-1 for different reagents. The PT assays showed a marked degree of difference. In general, the Quick PT type assays were more sensitive compared with the Owren type PT assays. The results from antithrombin assays were dependent on the type of reagent, with the Xa-based assay being sensitive for rivaroxaban with an estimated increase of 0.09 IU mL-1 per 100 mu g L-1 rivaroxaban. There were only minor effects on fibrinogen assays based on thrombin reagents. The APTT-based assay for APC resistance is affected in a dose-dependent manner whereas an assay based on the activation of coagulation at the prothrombinase level was unaffected. Conclusions: Different assays, and even different reagents within an assay group, display variable effects by therapeutic concentrations of rivaroxaban.
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| 4. |
- Hillarp, Andreas, et al.
(författare)
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Local INR calibration of the Owren type prothrombin assay greatly improves the intra- and interlaboratory variation
- 2004
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 91:2, s. 300-307
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Tidskriftsartikel (refereegranskat)abstract
- In 1999, a simplified procedure for calibration of the Owren prothrombin time (Owren PT) assay was introduced by a working group of the organisation for national quality assurance in laboratory medicine in Sweden. The new protocol allowed local calibration by means of only two lyophilised national plasma calibrators and expression of results as an international normalized ratio (INR). This is our report of a three-year follow-up involving the analysis of data from all laboratories, in hospitals (n=88 in 2002) and primary health care units (n=246 in 2002) that perform the Owren PT assay in Sweden. The interlaboratory variation was significantly improved after the introduction of the new calibration procedure. For the larger hospital-based laboratories, the mean coefficient of variation (CV) was reduced from 7.9% to 5.2% (p<0.0001) when analysing test materials with INR range 2-4. In the higher INR range (>4), the CV was reduced even further, from 10.4% to 6.8% (p<0.0001). The corresponding results from smaller laboratories in the primary health care units showed a similar decrease in CV from 8.2% to 5.7% in the INR range 2-4 (p<0.0001). At the INR range >4, the CV was reduced from 9.5% to 7.8%. The intralaboratory variation was also improved for both types of laboratory categories. This study shows an improved precision, with CV less than 6% at the therapeutic INR range, for both hospital-based laboratories and smaller laboratories in the primary health care system. The results indicate that the Owren PT assay is well suited for local INR calibration employing only two calibrant plasmas in a simplified procedure.
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| 5. |
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| 6. |
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| 7. |
- Hillarp, Andreas, et al.
(författare)
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Mer samstämmiga laboratorieresultat efter övergången till INR. Skillnaderna mellan sjukhus- och primärvårdslaboratorier utjämnade
- 2002
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Ingår i: Läkartidningen. - 0023-7205. ; 99:50, s. 70-5073
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Tidskriftsartikel (refereegranskat)abstract
- In 1999 a new and simplified procedure for calibration of the Owren prothrombin time (Owren PT) assay was introduced in Sweden by the national external quality assessment scheme (Equalis). The new protocol allowed local calibration by means of lyophilised national plasma calibrators and expression of results as an international normalised ratio (INR). A two-year follow-up involving analysis of data from all laboratories that have returned results to Equalis is reported. There was a significant reduction in both between-laboratory and within-laboratory variation after the introduction of the new calibration procedure. For the larger hospital laboratories analysing external controls with INR>2, the mean coefficient of variation (CV) was reduced from 9.1% to 5.6% (P<0.0001). The corresponding results from smaller laboratories in the primary health care units showed a similar decrease in CV from 8.8% to 6.3% (P<0.0001). This study shows that the Owren PT assay is well suited for INR calibration employing calibrant plasmas.
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| 8. |
- Lindahl, Tomas, et al.
(författare)
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Effects of the oral, direct thrombin inhibitor dabigatran on five common coagulation assays
- 2011
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Ingår i: Thrombosis and Haemostasis. - : F K Schattauer Verlagsgesellschaft MBH. - 0340-6245 .- 2567-689X. ; 105:2, s. 371-378
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Tidskriftsartikel (refereegranskat)abstract
- Dabigatran is an oral, reversible thrombin inhibitor that has shown promising results in large clinical trials. Laboratory monitoring is not needed but the effects on common coagulation assays are incompletely known. Dabigatran was added to plasma from healthy subjects in the concentration range 0-1,000 μg/l and analysed using several reagents for activated thromboplastin time (APTT), prothrombin time (PT), fibrinogen, antithrombin, and activated protein C resistance. Typical trough concentrations are about 50 μg/l, peak concentrations 100-300 μg/l. At 100 μg/l all APTT-results were prolonged. The concentration required to double APTT ranged between 227 and 286 μg/l, the responses for all five reagents were similar. PT-reagents were much less affected with almost no samples above INR 1.2 at 100 μg/l. The effect was sample dilution dependent with PT Quick type more sensitive than PT Owren type methods. If a patient on dabigatran has prolonged APTT, >90 seconds, and Quick PT INR>2 or Owren PT INR>1.5 over-dosing or accumulation of dabigatran should be considered. Two of four fibrinogen reagents underestimated the fibrinogen concentration considerably at expected peak concentration. Methods based on inhibition of thrombin over-estimated the antithrombin concentration, but not Xa-based. The APC-resistance methods over-estimated the APC-ratio, which may lead to miss-classification of factor V Leiden patients as being normal. Different coagulation assays, and even different reagents within an assay group, display variable effects at therapeutic concentrations of dabigatran. Some of these assay variations are of clinical importance, thus knowledge is needed for a correct interpretation of results.
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| 9. |
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| 10. |
- Själander, Anders, et al.
(författare)
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Menorrhagia and minor bleeding symptoms in women on oral anticoagulation.
- 2007
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 1573-742X .- 0929-5305. ; 24:1, s. 39-41
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Tidskriftsartikel (refereegranskat)abstract
- Background Oral anticoagulation (OA) is a common treatment with a known risk of fatal or major bleeding, but also minor bleeding symptoms and menorrhagia can cause substantial discomfort and necessitate medical or surgical interventions. The extent of these side effects is however not previously reported. The objective of this study is to assess the frequency of minor bleeding symptoms and menorrhagia attributed to OA treatment. Methods Ninety fertile women between 15 and 49 years-of-age on OA treatment completed an inquiry at the anticoagulation clinics of Malmö, Lund and Gothenburg, Sweden. Results The frequency of minor bleeding symptoms was significantly increased during OA treatment (P < 0.05) except for hematuria. The incidence of bleeding after tooth extraction (>3 h) increased from 3.0 to 45.2%, easy bruising 17.8–75.6%, epistaxis 11.1–23.6%, gingival bleeding 22.2–48.3% and hematuria 10.0–15.6% (Table 1). Hematemesis was reported in 5.6% prior to as compared to 14.4% during OA treatment, blood in the feces in 8.9 and 18.9%, respectively. Mean duration of menses increased from 5.6 to 6.1 days (P < 0.01) and reported menorrhagia from 44.2 to 70.8% (P < 0.001). Eighteen percent were treated for menorrhagia before and 29.9% during OA treatment (P < 0.01). Conclusions OA treatment is known to confer increased risk of fatal or major bleeding. This study shows that fertile women on OA also experience significantly increased minor bleeding symptoms including menorrhagia that may considerably impair quality of life.
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