Determining Thrombogenicity: Using a Modified Thrombin Generation Assay to Detect the Level of Thrombotic Event Risk in Lupus Anticoagulant-Positive Patients.

The aim of this study was to determine the thrombogenicity of lupus anticoagulant (LA) antibodies using a modified thrombin generation assay (TGA) with the addition of activated protein C (APC) in a group of 85 patients with LA-positive samples. Of these, 58 patients had clinical manifestations of antiphospholipid syndrome (APS) according to the Sydney criteria classification, i.e., each patient had thrombosis or foetal loss, and 27 patients did not show any clinical manifestations of APS. A comparison of the two groups' TGA results revealed statistically significant differences (Fisher's test p = 0.0016). The group of patients exhibiting clinical manifestations of APS showed higher thrombogenicity in 56.9% of patients, while the group of patients not yet exhibiting clinical manifestations of APS showed higher thrombogenicity in 25.9% of patients. There were no significant differences in the specificity of the TGA test between the groups of patients exhibiting similar clinical manifestations. Receiver operating characteristic curve analysis showed a more significant relationship (p = 0.0060) for TGA than for LA titre (p = 0.3387). These data suggest that the determination of LA thrombogenicity with the TGA assay leads to an increased prediction of the manifestation of a thromboembolic event. Our findings appear to be particularly relevant for the prediction of thrombotic events in patients with laboratory-expressed APS and no clinical manifestations.

Monitoring the Antiplatelet Therapy Efficacy in Patients with Acute Ischemic Stroke.

BACKGROUND: Stroke is one of the leading causes of morbidity and mortality in populations of developed countries. Ischemic strokes account for 85 - 90% of all strokes, with the majority of strokes of non-cardioembolic pathogenesis. Platelet aggregation plays a key role in arterial thrombus formation. Therefore, effective antiplatelet therapy plays a key role in secondary prevention. Acetylsalicylic acid (ASA) is the main drug of choice, and clopidogrel therapy is another recommended treatment option. Monitoring of the efficacy of antiplatelet therapy has been intensively studied in patients with coronary artery disease in the context of coronary stent implantation. It is not yet part of the routine procedure in patients with stroke [1-3]. METHODS: This study investigated the efficacy of antiplatelet therapy with ASA and clopidogrel using optical and impedance aggregometry in 42 consecutive patients with acute ischemic stroke. Patients were treated with throm-bolysis at baseline and platelet function was examined 24 hours after administration, focusing on the occurrence of platelet hyperaggregability and assessing the efficacy of any chronically administered antiplatelet therapy. Subsequently, patients were administered a loading dose of ASA or clopidogrel followed by a check of its efficacy 24 hours after administration. In the following days, the maintenance dose of the drug was continued and regular laboratory monitoring of treatment efficacy was performed every 24 hours. RESULTS: In patients with atherothrombotic stroke indicated for antiplatelet therapy, monitoring of residual platelet activity allowed for detection of potentially atrisk patients. These were 35% (9% borderline ineffective) of patients taking ASA and 55% (18% borderline ineffective) of patients treated with clopidogrel. The dose was adjusted, increased the administered treatment and no recurrence of stroke was observed in this study group at 1-year follow-up. CONCLUSIONS: Personalized antiplatelet therapy based on platelet function tests appears to be a useful method to reduce the risk of recurrent vascular events.

The safety and efficacy of a new anticoagulation strategy using selective in-circuit blood cooling during haemofiltration--an experimental study.

BACKGROUND: Selective in-circuit blood cooling was recently shown to be an effective anticoagulation strategy during short-term haemofiltration. The aim of this study was to examine the safety of this novel method and circuit life. METHODS: Fourteen pigs were randomly assigned to receive continuous haemofiltration with anticoagulation achieved either by selective cooling of an extracorporeal circuit (ECC) (COOL; n = 8) or through systemic heparinization (HEPARIN; n = 6). Before (T0) as well as 1 (TP1) and 6 h (TP6) after starting the procedure the following parameters were assessed: animal status, variables reflecting haemostasis, oxidative stress, inflammation and function of blood elements. RESULTS: All animals remained haemodynamically stable with unchanged body core temperature and routine biochemistry. Regional ECC blood cooling did not alter clinically relevant markers of haemostasis, namely activated partial thromboplastin and prothrombin times, thrombin-antithrombin complexes, von Willebrand factor and plasminogen activator inhibitor-1. Platelet aggregability, serum levels of free haemoglobin, leukocyte count, oxidative burst and blastic transformation of T-lymphocytes were all found to be stable over the treatment period in both groups. ECC blood cooling affected neither plasma malondialdehyde concentrations (a surrogate marker of oxidative stress) nor plasma levels of cytokines (tumour necrosis factor-α, interleukin-6 and -10). While the patency of all circuits treated with systemic heparin was well maintained within the pre-selected period of 24 h, the median filter lifespan in the COOL group was 17 h. CONCLUSION: Utilizing clinically relevant markers, selective in-circuit blood cooling was demonstrated to be a safe and feasible means of achieving regional anticoagulation in healthy pigs. The long-term safety issues warrant further evaluation.

Sensitization to inorganic mercury could be a risk factor for infertility.

INTRODUCTION: Heavy metals can negatively influence the reproduction due to the fact that they are able to impair the immune reactions including autoantibody production in susceptible individuals. In such a way the infertility could be also caused by altered pathologic immune reaction. AIM OF THE STUDY: To investigate the in vitro lymphocyte reaction after stimulation with metals and production of gamma interferon and antisperm antibodies in supernatants after lymphocyte stimulation in patients with infertility and with proven antisperm antibodies in their serum. The cause of antisperm antibodies presence was not determined. METHODS: The diagnosis of metal allergy was performed by the lymphocyte proliferation method modified for metals (MELISA) in supernatants of tissue cultures of lymphocytes without the antigen stimulation and after stimulation with mercury chloride, the in vitro production of gamma interferon and antisperm antibodies was studied by ELISA. RESULTS: More than 50% of patients were reacting to mercury, iron, aluminium and silver as mean by lymphocyte reactivity. When compared the lymphocyte reaction in patients with and without mercury allergy we found that the lymphocytes of patients with mercury intolerance produced less gamma interferon and more antisperm antibodies in supernatants after mercury stimulation of their lymphocytes. CONCLUSION: In patients with metal intolerance diagnosed by the MELISA test the release of metal ions from dental materials can be one of the stimulating factors which may adversely affect fertility.