Coagulation abnormalities in serial double‐filtration plasmapheresis

Intensive plasma exchange can transiently alter the hemostatic system. However, the effect of serial double filtration plasmapheresis (DFP) on the hemostatic system has not been adequately described. In this study, we sought to characterize the hemostatic effects of DFP in 32 myasthenia gravis patients who received one course of DFP treatment for five consecutive sessions within 10 days. Platelet count, prothrombin time (PT), partial thromboplastin time (PTT), and serum levels of albumin, globulin, cholesterol, and fibrinogen were measured before and after the course of DFP. Patients were divided into mild hypofibrinogenemia (MH) and severe hypofibrinogenemia (SH) groups based on post‐plasmapheresis residual levels of fibrinogen above or below 70 mg/dl. The baseline fibrinogen level was significantly lower in the SH group (P < 0.01). After five sessions of DFP, the fibrinogen level was reduced to below 70 mg/dl in 14 patients (44%). The percentage of excessive prolongation of PT or PTT was significantly higher in the SH group. The SH group also had higher reduction rates of globulin and cholesterol (P < 0.05). Oozing in the punctured site of the central venous catheter occurred in 6 out of 26 patients, with four cases in the MH group and two in the SH group. There was no difference in the overall incidence of bleeding complications between the two groups. Only one episode of clinically overt bleeding occurred during the study after a large‐bore femoral catheter was removed soon after the patient had received five consecutive daily treatments. The bleeding stopped after transfusion of 6 units of fresh frozen plasma. In conclusion, despite the obvious reduction of fibrinogen level and the modest decrease in platelet count after an intensive course of DFP treatment, the low incidence of clinically overt bleeding confirmed the safety of DFP. J. Clin. Apheresis 16:139–142, 2001. © 2001 Wiley‐Liss, Inc.     

Polyamine‐promoted autoactivation of plasma hyaluronan‐binding protein

See also Kanse SM, Etscheid M. Factor VII activating protease (FSAP): caught in the cross‐fire between polycations and polyanions. This issue, pp 556–8. Summary. Background: Plasma hyaluronan‐binding protein (PHBP), a protease implicated in extracellular proteolysis, consists of multiple domains: an N‐terminal region (NTR), three epidermal growth factor (EGF)‐like domains, a kringle domain, and a protease domain. PHBP circulates as a single‐chain proenzyme (pro‐PHBP), which is converted to an active, two‐chain form through autoproteolysis. Objective: To understand the mechanism of autoactivation. Here, we report that polyamine induces the formation of pro‐PHBP autoactivation complex, in which an intermolecular interaction between NTR and the third EGF‐like domain (E3) plays a role. Methods: Using a series of pro‐PHBP mutants that partially lack functional domains, polyamine‐induced pro‐PHBP autoactivation was investigated in terms of enzyme activity, protein interaction, and inhibition by carminic acid, an anthraquinone compound identified in this study. Results: Polyamine enhanced intermolecular binding of pro‐PHBP, but not of mutant pro‐PHBP that partially lacked NTR (ΔN). Carminic acid inhibited intermolecular pro‐PHBP binding and specifically abolished polyamine‐induced autoactivation. NTR bound to pro‐PHBP and ΔN, but its binding was minimal to a mutant that lacked E3. The NTR‐ΔN binding was inhibited by a combination of polyamine and carminic acid, but each compound alone was ineffective. Conclusions: We infer from the data that (i) polyamine modulates intramolecular NTR‐E3 interaction to allow intermolecular binding between NTR and E3 in another pro‐PHBP molecule to form an autoactivation complex, and (ii) carminic acid inhibits polyamine‐modulated intermolecular NTR‐E3 binding. Polyamine concentrations are higher in cells and tissues with inflammation and malignancy. Polyamine leakage from legions through cell death or tissue injury may account for physiologically relevant pro‐PHBP activation.     

Motorcycle‐related major trauma: On‐road versus off‐road incidence and profile of cases

Objective: To describe and compare the incidence and profile of on‐ and off‐road motorcycle‐related major trauma (including death) cases across a statewide population. Methods: A review of prospectively collected data on adult, motorcycle‐related major trauma cases from 2001 to 2008 was conducted. Major trauma survivors were identified from the population‐based Victorian State Trauma Registry, and deaths were extracted from the National Coroners Information System. Poisson regression was used to test for increasing incidence using two measures of exposure: population of Victoria aged ≥16 years, and registered motorcycles. Results: There were 1157 major trauma survivors and 344 deaths with motorcycle‐related injuries over the study period. There was no change in the incidence of motorcycle‐related major trauma (both survivors plus deaths) (Incident Rate ratio [IRR]= 1.14, 95% confidence interval [CI] 0.94–1.37) over the study period. Similarly, there was no change over time in the incidence of on‐road motorcycle‐related injury (survivors plus deaths) per 100 000 population (IRR = 1.03, 95% CI 0.84–1.27). However, the incidence of off‐road motorcycle‐related injury (survivors plus deaths) increased over the study period (IRR = 1.69, 95% CI 1.10–2.60). Among survivors and deaths, 882 (76%) and 301 (87.5%) cases, respectively, occurred on road. Conclusions: Off‐road motorcycle‐related major trauma has increased and this has not been targeted in injury prevention campaigns in Australia. The incidence of on‐road motorcycle‐related death in adults has decreased. Preventive strategies to address on‐road injuries have been enforced and these are expected to lead to further reduction of on‐road motorcycle crashes in the future.     

Cyclosporine‐impregnated allograft bone sterilized with low‐temperature plasma

Deep‐freezing, freeze‐drying and gamma (γ)‐irradiation have deleterious effects on bone healing and mechanical properties of allograft bones. We tried preparing bone allografts using cyclosporine plus low‐temperature‐plasma sterilization. To explore the feasibility of this method of preparation, segmental defects in the right radii of rabbits were repaired with cyclosporine‐impregnated allograft bones (CABs) sterilized with low‐temperature‐plasma (in the study group) and deep‐frozen/freeze‐dried irradiated allograft bones (D/FIABs) (in the control group). X‐ray and quantitative histological analysis, peripheral blood T lymphocyte subset analysis and CD₂₅ molecule immunohistochemistry stain, the four‐point bending test and safety evaluations were respectively conducted to compare bone‐healing, immunosuppression, mechanical properties and safety between the two groups. X‐ray scores were higher in the study group than those in the control (p = 0.032). There were significant differences in new bone areas at most repairs in both groups (p < 0.05). There were no significant differences in the percentages of CD₄⁺ T, CD₈⁺ T, ratios of CD₄⁺ T:CD₈⁺ T or serum concentrations of GPT/Cr in both groups (p > 0.05). At 16 weeks postoperatively, the density of CD₂₅ molecules in the control group was higher than that in the study group. The ultimate loading in the study group was significantly higher than that in the control (p = 0.048). Bone marrow stromal cells (BMSCs) grew thickly around and on the surface of a cyclosporine‐impregnated allograft. Livers and kidneys in the study and control groups remained histologically normal at 7 days postoperatively. These results indicate that the CAB might be a better material than the D/FIAB in terms of bone healing, preservation of mechanical properties and immunosuppression without severe side‐effects. Copyright © 2010 John Wiley & Sons, Ltd.     

Coagulation parameters in apheresis and leukodepleted whole-blood plasma during storage

BACKGROUND: Thawing fresh-frozen plasma (FFP) may cause delay in delivery, and one approach to circumvent this is to store plasma at +4 degrees C. Thawed plasma is commonly discarded after a few days of storage, owing to the assumption that coagulation factor activity decreases to clinically unacceptable levels. STUDY DESIGN AND METHODS: Eighteen apheresis plasma (AP) units were collected from blood donors. The collected plasma was divided into two equal parts: one part frozen at -74 degrees C as FFP and one part stored at +4 degrees C as fresh liquid plasma (FLP). Thirty-nine units of whole blood (WB) were collected from blood donors and leukodepleted by inline filtration, followed by plasma separation. Twenty plasma units were frozen at -74 degrees C as FFP and 19 plasma units were stored at +4 degrees C as FLP for 28 days. Plasma aliquots were collected before freezing and immediately after thawing FFP and before and during storage of FLP at Days 14 and 28. Factor (F)V, FVIII, D-dimers, and C1-esterase inhibitor levels were assessed. RESULTS: No significant differences in coagulation factor levels were assessed between FLP prepared from AP and FLP prepared from WB. FV and FVIII levels decreased on average 25 and 50 percent, respectively, at Day 14 of storage. C1-esterase inhibitor and D-dimers levels were not affected. CONCLUSION: Leukodepleted apheresis and WB plasma stored for 14 days retain sufficient levels of FV and FVIII activity for maintenance of normal hemostasis and could therefore be considered useful in selected clinical situations.     

Coagulation parameters of thawed fresh-frozen plasma during storage at different temperatures

Once thawed, fresh-frozen plasma (FFP) should be used, according to guidelines, within 24 h. In hospital practice, this may be associated with wastage. This study has been performed to investigate the coagulation levels of thawed quarantine FFP as used in the Netherlands. Five units of quarantine FFP, obtained by plasmapheresis, were thawed and by sterile docking divided into satellite bags (SB). SB 2-4 were stored at room temperature (RT) for, respectively, 1, 3 and 6 h and SB 5-9 at 4 degrees C for 6, 12 and 24 h and 1 and 2 weeks. At each time point, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, factor V (FV), factor VIII (FVIII) and ADAMTS13 activity were measured. During storage at RT for up to 6 h, no major differences were found in the levels of FV, PT, fibrinogen and ADAMTS13 activity. FVIII activity showed a decrease of 16% and the APTT was prolonged by 6%. During storage at 4 degrees C for 2 weeks, FV and FVIII were reduced by 35 and 45%, respectively. The APTT and PT were prolonged by 17 and 15%, respectively. Fibrinogen was decreased by 8%. No change in ADAMTS13 activity was found. FFP stored at RT for 6 h or at 4 degrees C for 2 weeks can provide sufficient support for adequate haemostasis except for patients with a known deficiency for FVIII and can be used for plasmapheresis in patients with thrombotic thrombocytopenic purpura (TTP).     

Hemodynamic assessment of indomethacin‐induced fetal heart failure in high‐output state

Hemodynamic study was performed on a 32‐year‐old woman presenting at 27 weeks' gestation. Ultrasound revealed a single normal fetus with mild cardiomegaly, polyhydramnios, and placental chorioangioma. Doppler study showed increased middle cerebral artery peak systolic velocity, normal Tei index, and forward flow of “a” wave with normal preload in the ductus venosus. Twelve hours after initiation of indomethacin for tocolysis, frank hydrops fetalis developed rapidly. The right ventricle showed poor contractility and performance. Markedly increased preload in ductus venosus with reversed “a” wave and pulsations in the umbilical vein were demonstrated. This study suggests that indomepacin treatment in fetal high‐cardiac output state should be used with extreme caution. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 41 :438–440, 2013     

Circulating adiponectin and plasma fatty acid profile

BACKGROUND: The amount and type of fat in the diet influence the development of obesity and related inflammatory activity. Knowledge of the possible influence of dietary habits on circulating adiponectin, a molecule with putative antiinflammatory properties, may be helpful in preventing atherosclerosis and type 2 diabetes. METHODS: The association between dietary fat, as inferred from plasma fatty acid composition (gas-liquid chromatography), and circulating adiponectin (RIA) was evaluated in 116 healthy individuals. RESULTS: The proportion of saturated fatty acids in plasma was significantly associated with circulating adiponectin concentration (r = -0.24; P = 0.01). Specifically, percentage of palmitic acid (C16:0) was significantly associated with lower adiponectin concentration (r = -0.28; P = 0.002), particularly among women (r = -0.37; P = 0.02) and nonsmokers (r = -0.30; P = 0.007). Percentage of myristic acid (C14:0) was also significantly associated with lower adiponectin among nonsmokers (r = -0.26; P = 0.02) and women (r = -0.39; P = 0.01). The other fatty acids were not significantly associated with adiponectin except for eicosanoic acid (C20:1 omega-9), which was significantly and positively associated with adiponectin in all individuals (r = 0.23; P = 0.01). This latter association was most significant in smokers (r = 0.43; P = 0.007). In a multivariate regression analysis to predict circulating adiponectin, after controlling for age, body mass index, waist-to-hip ratio, and the individual remaining fatty acids, the percentages of palmitic (P = 0.005) and eicosanoic acid (P = 0.03) contributed independently (6% and 3%, respectively) to adiponectin variance. Among nonsmokers, the percentages of palmitic acid (P = 0.01) and omega-3 fatty acids contributed 8% and 7%, respectively, to adiponectin variance. Among smokers, the percentage of eicosanoic acid (P = 0.03) contributed to 10% of adiponectin variance, independently of body mass index, age, waist-to hip ratio, and the remaining individual fatty acids. CONCLUSIONS: Saturated and omega-3 fatty acids of dietary origin (as inferred from plasma fatty acid concentration) are associated with circulating adiponectin concentrations in healthy humans. The proportion of eicosanoic acid also appears to be positively associated with circulating adiponectin. The knowledge of how these interactions occur may be helpful in the planning of dietary measures aimed at the modulation of inflammatory activity.     

Injectable freeze‐dried chitosan‐platelet‐rich‐plasma implants improve marrow‐stimulated cartilage repair in a chronic‐defect rabbit model

Bone‐marrow stimulation (BMS) improves knee‐joint function but elicits incomplete repair. Liquid chitosan (CS)–glycerol phosphate/blood clots have been shown to improve BMS‐based cartilage repair. Platelet‐rich‐plasma (PRP)—a rich source of growth factors and cytokines—improves recruitment and chondrogenic potential of subchondral mesenchymal stem cells. We hypothesised that repair response in a rabbit chronic‐defect model will improve when freeze‐dried CS/PRP is used to augment BMS. Bilateral trochlear defects created in New Zealand white rabbits were allowed to progress to a chronic stage over 4 weeks. Chronic defects were debrided and treated by BMS in second surgery, then augmented with PRP (BMS + PRP) or freeze‐dried CS/PRP implants (BMS + CS/PRP). The quality of 8‐week repair tissue was assessed by macroscopic, histological, and micro computed tomography (Micro‐CT) analysis. ICRS macroscopic scores indicated fibrocartilaginous or fibrous repair in control defects that were improved in the BMS + CS/PRP group. An overall improvement in repair in BMS + CS/PRP group was further confirmed by higher O'Driscoll scores, %Saf‐O and %Coll‐II values. Micro‐CT analysis of subchondral bone indicated ongoing remodelling with repair still underway. Quality and quantity of cartilage repair was improved when freeze‐dried CS/PRP implants were used to augment BMS in a chronic defect model.