Are thrombocytopenia and platelet transfusions associated with major bleeding in preterm neonates? A systematic review.

Over 75% of severely thrombocytopenic preterm neonates receive platelet transfusions to prevent bleeding, but transfusion guidelines are based mainly on expert opinion. The aim of this review was to investigate whether platelet counts, platelet transfusions or platelet indices are associated with major bleeding in preterm neonates. We performed a systematic search of the EMBASE and MEDLINE databases until December 2017. We included randomized trials, cohort and case control studies. (Prospero: CRD42015013399). We screened 8734 abstracts and 1225 fulltexts, identifying 36 eligible studies. In 30, timing of the platelet counts or transfusions in relation to the bleeding was unclear. Of the remaining six studies, two showed that thrombocytopenia was associated with increased risk of bleeding, two showed no such assocation, and three showed lack of an association between platelet transfusions and bleeding risk. No studies assessing platelet indices were found. The study results suggest that prophylactic platelet transfusions may not reduce bleeding risk in preterm neonates.

Ribavirin rather than PEG-interferon pharmacodynamics predict nonresponse to antiviral therapy in naive chronic hepatitis C patients.

Twenty to fifty per cent of patients with chronic hepatitis C (CHC) experience nonresponse to current antiviral therapy, which may relate in part to ribavirin or PEG-interferon pharmacodynamics. We evaluated potential relevance of various factors for nonresponse. Two hundred forty-two naive CHC patients who received in a previous trial at least 24 weeks of antiviral therapy, including PEG-interferon alfa-2b and ribavirin, were analysed. Of them, 53% were infected with hepatitis C virus (HCV) genotype 1-4, 71% exhibited high viral load and 32% had severe fibrosis/cirrhosis. After 24 weeks of treatment, 39 patients (16%) were nonresponders. In multivariate analysis, lower serum ribavirin concentrations, HCV genotype 1-4 and higher baseline γ-GT predicted nonresponse. Week-24 ribavirin concentrations (2.2 vs 2.8 mg/L, P < 0.001), average ribavirin doses (14.5 vs 15.2 mg/kg per day, P = 0.03) and week-24 haemoglobin decreases (1.7 vs 2.0 mm, P = 0.02) were lower in nonresponders. Nonresponse rates increased progressively at decreasing ribavirin concentrations: 4%, 11%, 13% and 36% in case of serum ribavirin concentrations ≥4, 3-4, 2-3 and ≤2 mg/L, respectively (P = 0.001). Ribavirin concentrations correlated with both week-24 haemoglobin decreases (r = 0.42, P < 0.001) and ribavirin doses (r = 0.17, P = 0.01). Subgroup analysis in HCV genotype 1-4 patients revealed essentially the same results. Nonresponse was exceptional in HCV genotype 2-3 patients and associated with ribavirin concentrations <2 mg/L. Presumed interferon-related factors (average PEG-interferon doses and decreases in leucocytes, granulocytes, platelets and body weight) did not differ between nonresponders and responders. In conclusion, ribavirin- rather than PEG-interferon-related factors are independent and potentially modifiable predictors of nonresponse in treatment-naive CHC patients.

Effect of fat digestion on superior mesenteric artery blood flow in humans.

BACKGROUND AND AIM: Intraluminal nutrients stimulate superior mesenteric artery (SMA) blood flow. Of the macronutrients, especially fat affects the magnitude of the SMA blood flow response to a meal. Little is known however on the influence of fat hydrolysis on SMA flow. METHODS: We compared in eight healthy volunteers the SMA flow response (Doppler ultrasonography) to continuous intraduodenal fat perfusion (LCT, 240 kCal h(-1)) during conditions with normal hydrolysis (placebo, control), increased hydrolysis (pancreatic enzyme supplementation; 50 kU lipase) and impaired hydrolysis (orlistat 240 mg). RESULTS: Intraduodenal LCT significantly (P<0.01) increased SMA flow in all experiments over basal. The SMA flow response to fat during pancreatic enzyme supplementation (1.49 +/- 0.1 l min(-1)) was significantly (P<0.05) higher compared with placebo (1.11 +/- 0.16 l min(-1)). Lipase inhibition with orlistat did not significantly affect fat stimulated SMA flow compared with placebo: 0.89 +/- 0.08 l min(-1) versus 1.11 +/- 0.16 l min(-1). CONCLUSIONS: Administration of pancreatic enzymes significantly increases fat stimulated SMA flow. Fat digest products in the intestinal lumen contribute to the regulation of SMA blood flow.