Hemostasis during low molecular weight heparin anticoagulation for continuous venovenous hemofiltration: a randomized cross-over trial comparing two hemofiltration rates

INTRODUCTION: Renal insufficiency increases the half-life of low molecular weight heparins (LMWHs). Whether continuous venovenous hemofiltration (CVVH) removes LMWHs is unsettled. We studied hemostasis during nadroparin anticoagulation for CVVH, and explored the implication of the endogenous thrombin potential (ETP). METHODS: This cross-over study, performed in a 20-bed teaching hospital ICU, randomized non-surgical patients with acute kidney injury requiring nadroparin for CVVH to compare hemostasis between two doses of CVVH: filtrate flow was initiated at 4 L/h and converted to 2 L/h after 60 min in group 1, and vice versa in group 2. Patients received nadroparin 2850 IU i.v., followed by 380 IU/h continuously in the extracorporeal circuit. After baseline sampling, ultrafiltrate, arterial (art) and postfilter (PF) blood was taken for hemostatic markers after 1 h, and 15 min, 6 h, 12 h and 24 h after converting filtrate flow. We compared randomized groups, and 'early circuit clotting' to 'normal circuit life' groups. RESULTS: Fourteen patients were randomized, seven to each group. Despite randomization, group 1 had higher SOFA scores (median 14 (IQR 11-15) versus 9 (IQR 5-9), p = 0.004). Anti-Xa art activity peaked upon nadroparin bolus and declined thereafter (p = 0.05). Anti-Xa PF did not change in time. Anti-Xa activity was not detected in ultrafiltrate. Medians of all anti-Xa samples were lower in group 1 (anti-Xa art 0.19 (0.12-0.37) vs. 0.31 (0.23-0.52), p = 0.02; anti-Xa PF 0.34 (0.25-0.44) vs. 0.51 (0.41-0.76), p = 0.005). After a steep decline, arterial ETPAUC tended to increase (p = 0.06), opposite to anti-Xa, while postfilter ETPAUC increased (p = 0.001). Median circuit life was 24.5 h (IQR 12-37 h). Patients with 'short circuit life' had longer baseline prothrombin time (PTT), activated thromboplastin time (aPTT), lower ETP, higher thrombin-antithrombin complexes (TAT) and higher SOFA scores; during CVVH, anti-Xa, and platelets were lower; PTT, aPTT, TAT and D-dimers were longer/higher and ETP was slower and depressed. CONCLUSIONS: We found no accumulation and no removal of LMWH activity during CVVH. However, we found that early circuit clotting was associated with more severe organ failure, prior systemic thrombin generation with consumptive coagulopathy, heparin resistance and elevated extracorporeal thrombin generation. ETP integrates these complex effects on the capacity to form thrombin. TRIAL REGISTRATION : Clinicaltrials.gov ID NCT00965328

Characterization of Adherence of Nontypeable Haemophilus influenzae to Human Epithelial Cells

The adherence of 58 nontypeable Haemophilus influenzae isolates obtained from patients with otitis media or chronic obstructive pulmonary disease (COPD) and obtained from the throats of healthy individuals to Chang and NCI-H292 epithelial cells was compared. Otitis media isolates, but not COPD isolates, adhered significantly more to both cell lines than did throat isolates. Since high-molecular-weight (HMW) proteins are major adhesins of nontypeable H. influenzae, the isolates were screened for HMW protein expression by Western blotting with two polyclonal sera and PCR with hmw-specific primers. Twenty-three of the 32 adhering isolates (72%) and only 1 of the 26 nonadherent strains were HMW protein or hmw gene positive. Among the 32 isolates adhering to either cell line, 5 different adherence patterns were distinguished based on the inhibiting effect of dextran sulfate. Using H. influenzae strain 12 expressing two well-defined HMW proteins (HMW1 and HMW2) and its isogenic mutants as a reference, we observed HMW1-like adherence to both cell lines for 16 of the 32 adherent isolates. Four others showed HMW2-like adherence to NCI-H292. Of the three other patterns of adherence, one probably also involved HMW protein. Screening of the isolates with six HMW-specific monoclonal antibodies in a whole-cell enzyme-linked immunosorbent assay showed that the HMW proteins of COPD isolates and carrier isolates were more distinct from the HMW proteins from H. influenzae strain 12 than those from otitis media isolates. Characterization of the HMW protein of a COPD isolate by adherence and DNA sequence analysis showed that despite large sequence diversity in the hmwA gene, probably resulting in the antigenic differences, the HMW protein mediated the HMW2-like adherence of this strain

WILMS tumor and veno-occlusive disease .

Assessment of PLT-derived microparticles in patients with Wilms Tumo

Microparticles, plasminogen activator inhibitor (PAI-1), and antithrombin.

Retrospective assessment of endothelial damage during bone marrow transplantation in a group of pediatric patient

Elevated numbers and altered subsets of procoagulant microparticles in breast cancer patients using endocrine therapy

Microparticles (MP) can be elevated in cancer and thromboembolic disease. We hypothesized a role for MP in the hypercoagulable state in breast cancer patients using endocrine therapy, in whom both cancer and the use of endocrine therapy are independent risk factors for the development of thrombosis. Plasma samples were collected from 40 breast cancer patients using endocrine therapy (20 patients without metastases receiving adjuvant therapy and 20 patients with metastatic disease treated in a palliative setting) and from 20 female healthy controls. The endocrine therapy used was either an anti-estrogen or an aromatase inhibitor. Numbers and cellular origin of MP subsets were analyzed by flowcytometry. MP-associated procoagulant activity was measured using a thrombin generation assay using conditions that allow analysis of MP induced thrombin generation. Breast cancer patients using endocrine therapy had higher levels of MP positive for Annexin V (median 10000 vs 6500×10E6/l), P-selectin (330 vs 200×10E6/l), tissue factor (33 vs 15×10E6/l), and of MP derived from platelets (CD41) and leukocytes (CD45). Thrombin generation in plasma was dependent on the presence of MP and thrombin generation performed after addition of isolated MP to normal plasma showed a higher endogenous thrombin potential (1105 vs 1029 nM.min) in breast cancer patients. No differences were observed in MP levels and thrombin generation parameters between the metastatic and adjuvant group. Breast cancer patients using endocrine therapy have an increased MP number and a higher MP-dependent thrombin generation, irrespective of the presence of metastatic disease. Altered MP subset characteristics in these patients, especially the higher number of (activated) platelet derived MP and leukocyte derived MP, may in part explain a heightened procoagulant state in breast cancer patients using endocrine therap

Elevated procoagulant microparticles expressing endothelial and platelet markers in essential thrombocythemia

Essential thrombocythemia is a myeloproliferative neoplasm characterized by an increased risk of both arterial and venous thrombosis. The findings of this study show that patients with this disorder have elevated levels of platelet-and endothelium-derived microparticles, which may support thrombin generation and play a role in the pathophysiology of thromboembolic complications

New insights into sinusoidal obstruction syndrome

Entry criteria included patients who developed sinusoidal obstruction syndrome (SOS) at a single centre from January 2000 to December 2011. Patients who underwent haemopoietic stem cell transplantation or actinomicyn-based chemotherapy for nephroblastoma were selected. The study group comprised five patients with SOS who were compared with a control group of seven patients without SOS