NA was responsible for the laboratory assays and drafted parts of the manuscript AG helped to treat the patients, to review the charts of the patients and to review the manuscript. was significantly decreased in antibody-positive individuals (5.0 [2.5 to 7.5] versus 12.0 [7.5 to 24.0] hours; em P /em = 0.007) while was CVVH effectiveness (urea reduction percentage 17% [10% to 37%] versus 44% [30% to 52%]; em P /em = 0.04) on Lopinavir (ABT-378) heparin infusion. Anti-PF4/heparin antibody concentration was inversely correlated with CVVH duration. The receiver operating characteristic curve showed that a 6-hour cutoff was the best CVVH session duration to forecast a positive antibody test (level of sensitivity 71%, specificity 85%, and area under the curve 0.83). CVVH duration (32 [22 to 37] hours; em P /em 0.05) and urea reduction (55% [36% to 68%]; em P /em 0.03) were restored by danaparoid sodium infusion. Summary Repeated Lopinavir (ABT-378) hemofiltration-filter clotting in less than 6 hours was often associated with the presence of anti-PF4/heparin antibodies, regardless of the platelet count. In antibody-positive individuals, substitute of heparin by danaparoid sodium allowed the repair of CVVH period and effectiveness. Intro Heparin-induced thrombocytopenia (HIT) is an antibody-mediated adverse effect of heparin. The initial description concerned arterial thrombosis during unfractionated heparin (UFH) therapy [1]. HIT consequently has been connected with an increased risk of venous or arterial thrombosis [2-4]. The pathophysiology of HIT consists of the generation of anti-PF4/heparin antibodies, resulting in platelet and endothelial cell activation, leading to a procoagulant state [5]. Continuous veno-venous hemofiltration (CVVH) is definitely widely used for renal alternative. Because UFH often is used as anticoagulation therapy, individuals undergoing CVVH might be at risk for anti-PF4/heparin antibody generation or HIT. One medical feature of HIT in this context could be repeated hemofiltration-filter clotting [6,7]. In our medical intensive care unit (ICU), we recently observed two instances of HIT responsible for repeated hemofiltration-filter clotting in the absence of standard thrombocytopenia [8] and we then systematically measured the plasma anti-PF4/heparin antibody concentration in all individuals with repeated hemofiltration-filter clotting during CVVH, with no obvious cause. The purpose of this study was to statement a series of individuals in whom an anti-PF4/heparin antibody test was performed and to determine factors associated with a Rabbit Polyclonal to PPM1K positive test Lopinavir (ABT-378) in this particular setting in order to determine when one should perform the test. Materials and methods Individuals Between 1 November 2004 and 1 May 2006, 87 individuals underwent CVVH. Twenty-eight of these individuals experienced repeated ( 2) hemofiltration-filter clotting before the scheduled end of the CVVH session (24 to 48 hours) with no obvious cause and anti-PF4/heparin antibodies were assayed. We examined the charts of these 28 patients. In accordance with French law, because of the retrospective nature of the study, no written consent was requested. The study was authorized by our institutional review table. For each patient, general characteristics, platelet counts at various time points (admission, nadir [least expensive reported concentration], day time of anti-PF4/heparin antibody assay, and maximal count), and CVVH session duration and effectiveness (assessed from the urea reduction percentage before/after each session) were recorded. The duration of CVVH classes was from the Lopinavir (ABT-378) CVVH monitoring sheet, on which nurses regularly recorded data on an hourly basis. For each patient, an objective medical probability scoring system was used to calculate the likelihood of HIT according to the Four T-score [9]. For this purpose, we.