Agonist-induced platelet reactivity correlates with bleeding in haemato-oncological patients.

BACKGROUND AND OBJECTIVE: Prophylactic platelet transfusions are administered to prevent bleeding in haemato-oncological patients. However, bleeding still occurs, despite these transfusions. This practice is costly and not without risk. Better predictors of bleeding are needed, and flow cytometric evaluation of platelet function might aid the clinician in identifying patients at risk of bleeding. This evaluation can be performed within the hour and is not hampered by low platelet count. Our objective was to assess a possible correlation between bleeding and platelet function in thrombocytopenic haemato-oncological patients. MATERIALS AND METHODS: Inclusion was possible for admitted haemato-oncology patients aged 18 years and above. Furthermore, an expected need for platelet transfusions was necessary. Bleeding was graded according to the WHO bleeding scale. Platelet reactivity to stimulation by either adenosine diphosphate (ADP), cross-linked collagen-related peptide (CRP-xL), PAR1- or PAR4-activating peptide (AP) was measured using flow cytometry. RESULTS: A total of 114 evaluations were available from 21 consecutive patients. Platelet reactivity in response to stimulation by all four studied agonists was inversely correlated with significant bleeding. Odds ratios (OR) for bleeding were 0·28 for every unit increase in median fluorescence intensity (MFI) [95% confidence interval (CI) 0·11-0·73] for ADP; 0·59 [0·40-0·87] for CRP-xL; 0·59 [0·37-0·94] for PAR1-AP; and 0·43 [0·23-0·79] for PAR4-AP. The platelet count was not correlated with bleeding (OR 0·99 [0·96-1·02]). CONCLUSION: Agonist-induced platelet reactivity was significantly correlated to bleeding. Platelet function testing could provide a basis for a personalized transfusion regimen, in which platelet transfusions are limited to those at risk of bleeding.

The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study.

BACKGROUND AND AIM: Current treatment for irritable bowel syndrome (IBS) is suboptimal. Fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) may trigger gastrointestinal symptoms in IBS patients. Our aim was to determine whether a low FODMAP diet improves symptoms in IBS patients. METHODS: Irritable bowel syndrome patients, who had performed hydrogen/methane breath testing for fructose and lactose malabsorption and had received dietary advice regarding the low FODMAP diet, were included. The effect of low FODMAP diet was prospectively evaluated using a symptom questionnaire. Furthermore, questions about adherence and satisfaction with symptom improvement, dietary advice and diet were assessed. RESULTS: Ninety patients with a mean follow up of 15.7 months were studied. Most symptoms including abdominal pain, bloating, flatulence and diarrhoea significantly improved (p < 0.001 for all). 75.6%, 37.8% and 13.3% of patients had fructose, lactose malabsorption or small intestinal bacterial overgrowth respectively. Fructose malabsorption was significantly associated with symptom improvement (abdominal pain odds ratio (OR) 7.09 [95% confidence interval (CI) 2.01-25.0], bloating OR 8.71 (95% CI 2.76-27.5), flatulence OR 7.64 (95% CI 2.53-23.0) and diarrhoea OR 3.39 (95% CI 1.17-9.78), p < 0.029 for all). Most patients (75.6%) were adherent to the diet, which was associated with symptom improvement (abdominal pain, bloating, flatulence and diarrhoea all significantly associated with adherence, r > 0.27, p < 0.011). Most patients (72.1%) were satisfied with their symptoms. CONCLUSIONS: The low FODMAP diet shows efficacy for IBS patients. The current strategy of breath testing and dietary advice provides a good basis to understand and adhere to the diet.

Sympathetic nerve activity during prolonged rhythmic forearm exercise.

Exercise is a potent stimulus to activate the sympathetic nervous system. Previous work suggests that metabolite-sensitive muscle afferents are activated near the point of fatigue, and, when activated, they determine the muscle sympathetic nerve activity (MSNA) response to isometric forearm exercise. Yet, studies using a more prolonged rhythmic exercise paradigm suggest that the sympathetic nervous system can be activated in a more graded fashion. The purpose of this study was to determine whether metaboreceptor stimulation would also be responsible for MSNA responses to prolonged rhythmic isotonic forearm exercise. Subjects (n = 16) performed rhythmic isotonic forearm exercise at 25% maximal voluntary contraction for 30 min as we measured MSNA (microneurography). We observed progressive increases in MSNA with a peak increase of 161 units from a baseline value of 180 units. We also performed posthandgrip circulatory arrest (PHG-CA) in nine of these subjects. This maneuver isolates the metaboreceptor contribution to MSNA. During PHG-CA, delta MSNA values were not different from those observed during a freely perfused recovery period (n = 7). We also compared MSNA responses during the rhythmic paradigm with those seen during a static protocol at 40% of maximal voluntary contraction in five subjects. The two types of exercise caused similar increases in MSNA, but only the static paradigm was associated with a sustained MSNA response during PHG-CA. Finally, 31P-nuclear magnetic resonance was used to evaluate muscle metabolic responses during rhythmic and static forearm exercise (n = 6). Static exercise caused muscle acidosis and an increase in H2PO4-, whereas rhythmic exercise had no effect on muscle metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)