The impact of analytical variation of hemoglobin measurement on blood donors' hemoglobin and deferral rates.

BACKGROUND: Donors' hemoglobin (Hb) level must be tested before blood donation. Low Hb is the leading reason for donor deferral. Many donor-related and external factors associated with low Hb are known, but no studies have been conducted concerning the effects of analytical variation on donor Hb measurements and deferrals. STUDY DESIGN AND METHODS: The effects of donors' age, the seasonal and daily distribution of donations, and batch-to-batch variation in HemoCue Hb 201+ cuvettes on donors' capillary Hb (cHb) measurements and deferrals were analyzed for more than 1.7 million donor visits in 2010 to 2016 at a national blood establishment. Furthermore, approximately 3.1 million cHb measurements from the years 2000 to 2009 were included in analyses to correlate measured cHb value and Hb deferral rate. RESULTS: A significant correlation between the mean annual cHb and Hb deferral rate was observed in both women and men. The season of the donation was the strongest explanatory factor for the monthly variation of predonation cHb (explaining 25 and 31% of the variation in women and men, respectively). Batch-to-batch variation in HemoCue cuvettes explained 6.8% of monthly variation in women and 7.4% in men. Monthly changes in donors' age distribution explained 2.5% of monthly variation in women and 2.4% in men. CONCLUSION: Small and, in most clinical settings, negligible analytical variation in Hb measurement methods can have significant consequences when used for Hb screening of blood donors. This should be minimized by using methods in which analytical variation is under control and kept as low as possible.

Retrospective analysis of capillary hemoglobin recovery in nearly 1 200 000 blood donor returns.

Measuring the concentration of capillary hemoglobin (cHb) is a standard procedure before blood donation. To further assess the time period needed for cHb recovery after blood donation and to have a more in-depth understanding of features of recovery, we used data-mining tools in a large, retrospective data pool containing all 1 163 524 donor returns that took place in Finland in 2010 to 2015. The results show that the average recovery times for cHb to return back to the level preceding donation were substantially longer, over 200 days in all age groups, than were the minimum allowed donation intervals. cHb recovery was especially poor in women under the age of 30 who returned to donate soon after the minimum allowed donation interval. It was of interest that frequent donors recovered substantially faster, with the average recovery times of ∼100 days in men and ∼200 days in women, than did infrequent donors, suggesting that there is a subpopulation of donors who can donate frequently without fear of iron deficiency. Return interval in fact explained only 1% of the variation in cHb recovery, which points to unknown, individual features, such as genetic or lifestyle factors, warranting further studies and suggesting that simply extending the allowed donation intervals may not suffice to improve cHb recovery. The study demonstrates that data mining of blood bank records is a powerful tool for depicting features of blood donor population.

[Changes in consumption of blood products in Finland from 2007 to 2014]. / Verivalmisteiden kulutuksen muutokset Suomessa vuosina 2007-2014.

The Finnish Red Cross Blood Service (FRCBS) collects and distributes all cellular blood products in Finland. The use of red cells in Finland follows neither the aging of the Finnish population nor morbidity. The use of red blood cells has diminished 34% during the last 20 years and half of this decrease has taken place during the last three years. Use of platelet preparations per inhabitant in Finland clearly exceeds European median. An enhanced IT support for the blood supply chain is needed to maximize the effectiveness of use of blood products.

Season and time of day affect capillary blood hemoglobin level and low hemoglobin deferral in blood donors: analysis in a national blood bank.

BACKGROUND: Low hemoglobin (Hb) is the most common reason for temporary blood donor deferral. However, factors that affect Hb measurement may not portray donor health but reflect external circumstances. STUDY DESIGN AND METHODS: The effects of season, time of day, donor age, ABO, and D on capillary blood Hb level (cHb) and low Hb deferral were analyzed in 1,396,645 donor registrations from the years 2010 to 2014 in a national blood bank. RESULTS: cHb was lower in the summer (July mean 154.1 g/L in men, 139.6 g/L in women) and in the evening (7 pm mean 153.8 g/L in men, 138.9 g/L in women) than in the winter (January mean 156.9 g/L in men, 141.8 g/L in women) and in the morning (11 am mean 157.2 g/L in men, 142.8 g/L in women; all p < 0.0001). This affected donor deferral due to low Hb, with 7.8% donors deferred in July at 7 pm and 1.6% deferred in January at 11 am (p < 0.0001). With age, cHb increased in women and decreased in men. The lowest cHb was observed in blood group A (mean 154.9 g/L in men, 140.3 g/L in women) and the highest in blood group B (mean 156.6 g/L in men, 141.5 g/L in women). D had no practically significant effect on cHb. CONCLUSION: External factors, which do not reflect donor health, affect cHb and donor deferral due to low Hb. These factors should be considered when donor eligibility guidelines and procedures are developed.

Ischaemic stroke patients with heterozygous factor V Leiden present with multiple brain infarctions and widespread atherothrombotic disease.

Factor V Leiden (FVL) mutation is a risk factor for venous and, to a degree, arterial thrombosis. It is unknown whether and how FVL affects the manifestations of ischaemic stroke (IS). We assessed the clinical, laboratory, radiological, and prognostic characteristics in an observational study with adult IS patients having FVL. We tested 860 patients with first-ever IS for FVL and found 48 FVL positive patients. Detailed clinical, laboratory, and radiological evaluation were compared with that of 144 (1:3) gender and age matched IS patients without FVL. All patients underwent a prognostic evaluation at an average of five years follow-up. Despite the relatively young age (mean 48.5 years, range 44-54 years) of the FVL positive IS patients, peripheral arterial occlusive disease (PAOD), coronary artery disease (CAD), and previous transient cerebrovascular event occurred more frequently compared with controls. Family history of cardiovascular disease (CVD) and multiple silent brain infarctions were revealed in half of the FVL positive patients, whereas these were seldom encountered among controls. Stroke severity, long-term recovery, and recurrence rates seemed similar irrespective of FVL status. Our findings indicate that the clinical profile of IS patients with FVL associated with wider manifestation of atherothrombosis, positive family history of arterial thrombosis, and presence of multiple silent infarctions on brain images.

Activated protein C in the cardioplegic solution on a porcine model of coronary ischemia-reperfusion has deleterious hemodynamic effects.

PURPOSE: In reperfusion injury activation of coagulation and inflammation contribute to organ dysfunction. Activated protein C (APC) exhibits anticoagulant and anti-inflammatory properties in models of reperfusion injury. We hypothesized that APC could be cardioprotective after ischemia and cardiopulmonary bypass (CPB). METHODS: 20 pigs, undergoing 120 min of CPB and aortic cross-clamping, were randomized to receive 1 mg of human APC or placebo to the last cardioplegic solution given 15 min before declamping to the systemic circulation. After aortic declamping the heart was supported by continuing CPB for 30 min followed by 30 min surveillance. Thrombin-antithrombin complexes, neutrophil L-selectin expression in blood and myeloperoxidase activity (MPO) of myocardial biopsies were measured. RESULTS: There was no indication of APC-induced increased bleeding. Thrombin levels were significantly lower in the APC group than in the placebo group and so were the rates of thrombin formation during the first 3 min of reperfusion and between 10 and 30 min after declamping. There were no differences in MPO or in the proportion of L-selectin (+) to L-selectin (-) neutrophils between groups. Significant systolic hypotension in the APC group was observed at 30 and 45 min compared with the placebo group which associated with the increased mortality observed in the APC group (p = 0.019). CONCLUSIONS: Human APC in cardioplegic solution during CPB in pigs, decreased reperfusion induced thrombin formation with no associated bleeding. No anti-inflammatory effects of human APC were seen. However, in this setting, APC caused hemodynamic deterioration. The observed phenomenon could be explained by systolic hypotension potentially produced by the release of vasoactive substances generated by the APC activation of PARs in the endothelium.

Reorganization of oral anticoagulant (warfarin) treatment follow-up.

OBJECTIVE: To evaluate the impact of the reorganization of oral AC treatment management in a primary healthcare setting in terms of quality of care and cost of care. The evaluated reorganization involved the adoption of an AC nurse service model supported by the use of information and communication technology for storing and handling follow-up data. DESIGN: Statistical analysis of AC follow-up data, personnel task distribution and resource use analysis, and survey of personnel experiences. SETTING: The Paloheinä health station in Helsinki, Finland. SUBJECTS: All 122 Paloheinä patients on oral AC treatment and the related Paloheinä personnel. Also, follow-ups from two comparison health stations from Helsinki were used. MAIN OUTCOME MEASURES: Laboratory P-INR and follow-up density distributions before and after follow-up reorganization for Paloheinä and comparison station patients, task distribution, and personnel resource use in treatment guideline assignment before and after reorganization and gathered personnel experiences. RESULTS: No statistically significant changes (Pearson's chi-square test, p < 0.05) were observed in P-INR distributions, considering also the comparison stations. Adoption of the AC nurse model resulted in a 66%/34% task distribution between nurses and physicians in guideline assignment. Personnel resource use analysis showed a cost decrease of 1.61 euros per follow-up in guideline assignment. Users who responded to the survey were generally satisfied with the reorganization and its subjective impacts. CONCLUSION: Reorganization resulted in a potential reduction in cost of care per follow-up without a change in the observed quality of care in the Paloheinä setting. Personnel generally accepted the reorganization.

Stimulated release of endothelin-converting enzyme is simultaneous with tissue-type plasminogen activator and decrease in coronary heart disease.

OBJECTIVE: During the process of atherosclerosis the endothelium changes both structurally and functionally. We examined whether shedding of endothelin-converting enzyme (ECE), a metalloprotease responsible for endothelin production, is concomitant with tissue-type plasminogen activator (t-PA), and how atherosclerosis affects ECE release. DESIGN: Fourteen healthy volunteers and 24 patients with angiographically verified coronary heart disease (CHD) were investigated. ECE and t-PA releases were measured by a provocation test (20-min venous occlusion). RESULTS: Serum ECE activities were comparable in both groups before the venous occlusion test (in CHD patients 205 +/- 24 vs in healthy controls 204 +/- 40 pmol/ml/h, p = NS). However, delta-ECE (= the difference between, after, and before the venous occlusion test) was significantly lower in CHD patients than in controls (203 +/- 36 vs 338 +/- 43 pmol/ml/h, p = 0.02, respectively). Delta-t-PA was similar in both groups (22.3 +/- 4.4 vs 14.5 +/- 4.6 ng/ml, p = NS, respectively). Furthermore, t-PA and ECE values correlated in the CHD group in all pre-, post-venous occlusion test, and delta-venous occlusion test values (r = 0.56, p = 0.009; r = 0.62, p = 0.003; r = 0.54, p = 0.01, respectively). CONCLUSION: Vascular ECE release can be stimulated, and it is concomitant with t-PA release. A common location in endothelium may explain this simultaneous shedding. However, ECE levels do not rise in patients with CHD as markedly as in healthy patients. Atherosclerosis may explain reduced shedding of ECE.

Inhibition of platelet-collagen interaction: an in vivo action of insulin abolished by insulin resistance in obesity.

Insulin resistance is associated with an increased risk of atherothrombotic vascular disease, but the mechanisms are poorly understood. We determined how insulin in vivo regulates platelet activation in nonobese and obese subjects by using methods mimicking thrombus formation. Twelve nonobese (aged 42+/-2 years, body mass index 24.0+/-0.4 kg/m(2)) and 14 obese (aged 43+/-1 years, body mass index 37.2+/-1.5 kg/m(2)) subjects were studied under euglycemic hyperinsulinemic (3-hour insulin infusion of 1 mU. kg(-1). min(-1)) conditions. Before and at the end of hyperinsulinemia, the following were determined: (1) platelet-related early hemostasis (shear rate of approximately 4000 s(-1)) by platelet function analysis; (2) platelet deposition to collagen during whole-blood perfusion (shear rate of 1600 s(-1)); (3) aggregation responses to collagen, thrombin receptor-activating peptide, ADP, and epinephrine; and (4) platelet cGMP concentrations. Insulin action on glucose metabolism was 69% lower in the obese subjects (1.6+/-0.2 mg. kg(-1). min(-1)) than in the nonobese subjects (5.4+/-0.4 mg. kg(-1). min(-1), P<0.0001). The in vivo insulin infusion inhibited platelet deposition to collagen from 4.3+/-0.6x10(6) to 3.5+/-0.4x10(6) per square centimeter in the nonobese subjects (P<0.05) but failed to do so in the obese subjects (5.2+/-0.8x10(6) versus 5.5+/-0.7x10(6) per square centimeter, P=NS; P<0.01 versus nonobese subjects). Epinephrine- and ADP-primed closure times by platelet function analysis were prolonged by insulin in the nonobese but not the obese subjects (P<0.05 for between-group difference). In the nonobese subjects, insulin decreased aggregation to all agonists and significantly increased platelet cGMP concentrations (2.5+/-0.3 versus 3.2+/-0.5 pmol/10(9) for before versus after insulin, respectively; P<0.01). In the obese subjects, insulin did not alter collagen-induced aggregation or cGMP concentrations (1.9+/-0.2 versus 1.8+/-0.1 pmol/10(9) for before versus the end of in vivo hyperinsulinemia, respectively; P=NS). These data demonstrate that normal in vivo insulin action inhibits platelet interaction with collagen under conditions mimicking thrombus formation and reduces aggregation to several agonists. These platelet-inhibitory actions of insulin are blunted or absent in obese subjects and could provide 1 mechanism linking insulin resistance to atherothrombotic disease.