Cross-sectional epidemiological study to evaluate the cardiovascular profile of a cohort of blood donors

Background

Cardiovascular diseases are among the most frequent causes of mortality and morbidity in industrialised countries. The identification of subjects at high risk of cardiovascular diseases is one of the main aims of individual primary prevention programmes and is the essential background for instituting interventions aimed at reducing modifiable risk factors, from lifestyle changes to pharmacological interventions.

Donors and method

In order to evaluate the absolute global risk of cardiovascular disease in the population of blood donors of the Transfusion and Immunohaematology Centre of the Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena of Milan, we used the absolute global cardiovascular risk (CVR) score of the Progetto Cuore.Between September 2004 and June 2006, 11,093 blood donors were evaluated for their suitability for donating blood. The criteria for inclusion in the calculation of the individual values of the absolute global CVR score were: age between 35 and 65 years old, fasted for at least 12 hours, and no previous reported or diagnosed cardiovascular episodes. Each donor was also asked to provide written informed consent to participation in the study.The population of blood donors was divided into four groups according to their CVR score: CVR < 3%, CVR between 3% and 10%, CVR between 10% and 20%; CVR above 20%. The characteristics of the population were analysed subdividing the subjects according to age and gender.

Results

Although most of the blood donors belonged to the group with low CVR, it was nevertheless possible to identify a group of donors with high CVR.

Conclusions

It is to be hoped that CVR is calculated ever more widely in the population of blood donors in order to identify individuals at high CVR and also with the aim of reducing the levels of risk factors in the population with low or moderate CVR.     

Comparison of liquid phase radiobinding assay and solid phase ELISA for the measurement of insulin antibodies and insulin autoantibodies in serum

Sera containing insulin antibodies from 20 insulin-treated diabetic patients, sera containing insulin autoantibodies from 20 insulin-naive non-diabetic patients, and from 10 normal controls, were tested at 1:20 dilution in three different radioimmunoassays (RIA) and an enzyme linked immunosorbent assay (ELISA), using a highly purified human insulin ligand. The RIA using insulin radiolabelled at multiple sites detected insulin antibodies in 17/20 and insulin autoantibodies in 13/20 sera. The same RIA using A-14-monoiodinated insulin was sensitive to antibodies and autoantibodies in all the sera. The same RIA using sera after insulin extraction detected only 13/20 diabetic sera and 9/20 autoimmune sera as positive, owing to a substantial rise in non-specific binding of the control sera. ELISA was sensitive to insulin antibodies and autoantibodies in every case. When binding curves for ELISA and the most sensitive RIA were compared using serial dilutions of four insulin antibody containing sera and four insulin autoantibody containing sera, antibody titres varied from 1.1 to 3.8 times higher in ELISA, and autoantibody titres from 10.6 to 28.6 times higher in ELISA. These studies indicate that ELISA is more sensitive than RIA to insulin antibodies, and in particular to insulin autoantibodies.     

自然灾害后参与献血人数与平时献血人数的比较分析

目的:通过发生自然灾害后与平时献血人数的比较,探讨在发生自然灾害后献血人数显著增多的情况下,如何更好的将他们发展为固定献血者。方法:将2次自然灾害后1周内我中心流动采血车的无偿献血者与后1年同期进行对比。结果:灾害发生后献血人数显著增多,尤其以初次献血者增加更为明显,灾害发生后初次献血者分别占献血人数的72.12%与70.19%,而对照组为51.08%与54.97%。结论:在灾害发生后,献血人数成倍增加;建立一个持续性的激励政策,与献血做好沟通工作,有可能将他们发展成为固定献血者。     

Prevalence of antithrombin deficiency in healthy blood donors: A cross-sectional study

The prevalence of antithrombin (AT) deficiency In the general population has been variously estimated to be between 0.05 and 5 per 1,000 in the population; 2,491 blood donors were screened In an attempt to clarify this Issue using plasma samples taken from the blood donor units. From this initial population, 122 individuals were identified as having plasma AT levels lower than 2 standard deviations below the normal mean. Twenty-two samples had evidence that thrombin had been generated during blood collection and the remaining cohort of 100 blood donors were asked to return but only 59 complied. The data obtained from these 59 were compared with that from 51 age- and sex-matched control blood donors. Both groups of subjects were assessed for previous evidence, or family history, of thrombotic events, as well as exposure to risk factors associated with the development of deep vein thrombosis (DVT). All had venous blood samples taken from which the supernatant plasma was Immediately removed and quick frozen for later assaying. Only 6 of the 59 subjects with initial low AT levels had repeat AT-Xa levels below 0.80 units/ml (normal range 0.94 ± 0.14). Upon repeating the AT-Xa determinations on new samples from these six Individuals, only three were found again to be low. One was found to have a type 3 AT deficiency (an Arg47Cys substitution). The other two with a low AT level had mean functional AT-Xa levels of 0.61 and 0.71 units/ml, respectlvely, with correspondingly low AT:Ag levels consistent with a type 1 AT deficiency. Two of these three subjects has been in high risk situations without evidence of having developed DVT and none had evidence of venous reflux on Doppler venography. In addition, none had personal or family histories of previous thrombotic events. These present data Indicate that the prevalence of AT deficiency In our blood donor population is 2 per 1,000 (95% confidence intervals: 0.7-6/1,000). © 1994 Wiley-Liss, Inc.     

SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 outbreak in Milan

BackgroundThe Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The aim of this study was to examine the seroprevalence trends of SARS-CoV-2 in healthy asymptomatic adults, and the risk factors and laboratory correlates of positive tests.Materials and methodsWe conducted a cross-sectional study in a random sample of blood donors, who were asymptomatic at the time of evaluation, at the beginning of the first phase (February 24^th to April 8^th 2020; n=789). Presence of IgM/IgG antibodies against the SARS-CoV-2-Nucleocapsid protein was assessed by a lateral flow immunoassay.ResultsThe test had a 100/98.3 sensitivity/specificity (n=32/120 positive/negative controls, respectively), and the IgG test was validated in a subset by an independent ELISA against the Spike protein (n=34, p<0.001). At the start of the outbreak, the overall adjusted seroprevalence of SARS-CoV-2 was 2.7% (95% CI: 0.3–6%; p<0.0001 vs 120 historical controls). During the study period, characterised by a gradual implementation of social distancing measures, there was a progressive increase in the adjusted seroprevalence to 5.2% (95% CI: 2.4–9.0; 4.5%, 95% CI: 0.9–9.2% according to a Bayesian estimate) due to a rise in IgG reactivity to 5% (95% CI: 2.8–8.2; p=0.004 for trend), but there was no increase in IgM⁺ (p=not significant). At multivariate logistic regression analysis, IgG reactivity was more frequent in younger individuals (p=0.043), while IgM reactivity was more frequent in individuals aged >45 years (p=0.002).DiscussionSARS-CoV-2 infection was already circulating in Milan at the start of the outbreak. The pattern of IgM/IgG reactivity was influenced by age: IgM was more frequently detected in participants aged >45 years. By the end of April, 2.4–9.0% of healthy adults had evidence of seroconversion.     

Comparison of a novel micro-assay for insulin autoantibodies with the conventional radiobinding assay

Summary Measurement of insulin autoantibodies (IAA) with a novel micro radiobinding assay which requires only 20 μl of serum was compared with that in a conventional radiobinding assay which uses 600 μl of serum. IAA were measured with both assays in samples from 94 new onset insulin-dependent diabetes mellitus (IDDM) patients, 97 control subjects, and 48 first degree relatives of IDDM patients selected for having IAA in the conventional radiobinding assay. Overall, 227 (95 %) of 239 samples tested were concordant, and IAA levels correlated well (r ² = 0.7) between the two assays. Discordant results were obtained in 7 new onset patients, 4 control subjects, and 1 first degree relative, and these had low IAA levels in the respective assays. Sensitivity and specificity in the new onset IDDM patients and control subjects were 69 % and 98 % for the micro radiobinding assay and 72 % and 98 % for the conventional radiobinding assay. The use of the micro radiobinding assay should greatly facilitate islet related antibody screening, particularly in children. [Diabetologia (1998) 41: 681–683] Received: 8 October 1997 and in final revised form: 26 January 1998     

Hepatitis C virus genotypes in a cohort of Australian blood donors and haemophiliac and liver transplant patients

The aim of the present study was to characterize hepatitis C virus (HCV) genotypes using the INNO-LiPA HCV line probe assay and direct sequencing from three different HCV-RNA-positive (serum) groups: (i) blood donors (n= 59); (ii) haemophiliacs (n= 43); and (iii) patients undergoing liver transplantation (n= 26). Of 128 HCV-RNA-positive samples, 74 (58%) were genotype 1. Of these, 41 were genotype 1a, 32 were genotype 1b and one was genotype 1 indeterminate. Of the remaining 54 samples, seven (5%) were genotype 2a, two (2%) were genotype 2b, 26 (20%) were genotype 3a, three (2%) were genotype 4a, while 16 (12.5%) were of a mixed genotype. There was no significant difference between the three groups with regard to the prevalence of any specific genotype. However, in blood donors and haemophiliac patients there was a statistically significant difference in the occurrence of genotype 3a in patients with elevated alanine aminotransferase (ALT) levels (30.3%) compared with those patients with persistently normal ALT levels (5.6%; P= 0.004; x²) Genotype 3a was also uncommon in liver transplant patients (one of 14) with ‘sporadic’ HCV infection. Genotype 4a was detected only in liver transplant patients. These patients had originated from Egypt (n= 1), Italy (n= 1) and Romania (n= 1).     

广州市无偿献血人群HIV感染情况分析

目的分析广州市无偿献血人群艾滋病病毒（HIV）的感染情况,探究血液的安全隐患,探寻新形势下保证血液安全的策略。方法对2003-2011年间广州市无偿献血人群中,HIV感染者的检出情况进行分析。结果 9年间,广州市无偿献血人群中共检测出HIV感染者384例,感染率为12.32/10万,感染者数量逐年递增,其中17例为既往感染者（占4.43%,17/384）;检出HIV抗体不确定者56例,追踪随访38例,其中21例（占55.26%）发生阳转。结论在新的艾滋病流行形势下,广州市血液安全存在隐患,面临一定的风险,应加大艾滋病知识的宣传力度,发展低危、固定的无偿献血队伍,并采用更为准确有效的筛查技术,控制艾滋病病毒经血传播。     

Recombinant human erythropoietin in autologous blood donors: a dose-finding study

A dose-finding study of recombinant human erythropoietin (rhEPO) was performed in 60 autologous donors who donated 2 units of blood prior to orthopaedic or vascular surgery. The correction of phlebotomy-induced anaemia was studied in four groups of 15 patients who received 500 U/kg, 250 U/kg, 125 U/kg or no (controls) rhEPO subcutaneously twice per week during a 3-week period. Haemoglobin concentration in the 500 U/kg, 250 U/kg and 125 U/kg group and in the controls reached respectively 99·2, 98·8, 91·9 and 87·1% of pre-phlebotomy value. Flow cytometric analysis of reticulocytes showed a steady increase of reticulocyte count as the dose increased. Maximal levels of high fluorescence reticulocytes which represent early changes of erythropoiesis were reached after 7 d and decreased thereafter in each group. Serum ferritin decreased significantly to approximately 50% of baseline values in all groups; no differences in the decrease of serum ferritin were observed between the patients who received rhEPO and the controls. No severe adverse events were observed.
This study demonstrates a dose-related effect of rhEPO on erythropoiesis in autologous donors during the first 2 weeks. No further increase of reticulocytes was observed despite continued rhEPO therapy, which may be due to the inability of the mononuclear phagocytic system to release additional iron. To restore pre-phlebotomy haemoglobin concentration, a dose of 250 U/kg rhEPO was sufficient.     

Factors associated with granulocyte colony-stimulating factor-induced peripheral blood stem cell yield in healthy donors

BACKGROUND AND OBJECTIVES: Poor collection results are a clinical problem in granulocyte-colony stimulating factor (G-CSF)-induced peripheral blood stem cell (PBSC) collection in healthy donors. It would be beneficial to be able to predict the PBSC yield from allogeneic donors before mobilization or harvesting. MATERIALS AND METHODS: We examined the relationship between certain donor characteristics and the effectiveness of G-CSF-induced PBSC collection in 59 healthy family donors aged 3-63 years old (median 16 years). G-CSF was administered subcutaneously at 10 microg/kg for mobilization, daily for 5 days, and PBSC harvest using a continuous blood cell separator was started on day 5 of G-CSF treatment. Total cell yields were calculated as the number per unit of processed blood (l) per unit weight of the donor (kg). RESULTS: In a univariate analysis, the donor's age, body mass index (BMI), white blood cell (WBC) count before mobilization, and platelet count before and during mobilization were significantly correlated with the yield of mononuclear cells (MNC), CD34(+) cells and granulocyte-macrophage colony-forming units (GM-CFU). Younger age (P < 0.001), a low BMI (P = 0.002), a high WBC count before mobilization (P = 0.004), a high platelet count before (P = 0.012) and during (P < 0.05) mobilization, and a low speed of withdrawal (P = 0.019) were associated with a higher CD34(+) cell yield. No significant correlation was found for gender, the type of G-CSF, the serum level of G-CSF, the type of cell separator, or the type of blood access. A multivariate forward and backward stepwise selection regression analysis showed that the factors associated with CD34(+) cell yield were age, platelet count before and during mobilization, and circulating CD34(+) cell concentration on day 2 of G-CSF treatment. CONCLUSION: In this small preliminary study, we found that donor age is the most important factor in predicting G-CSF-induced PBSC yields. Old age and low platelet counts before mobilization might be useful indicators for identifying poor mobilizers. Further validation of these findings in a larger number of donors are needed to establish whether these findings apply to other populations.     

Clinical significance of elevated alanine aminotransferase in blood donors: a follow-up study.

Alanine aminotransferase (ALT) elevation in blood donors can be related to many variables such as viral hepatitis, overweight and ethanol consumption. BACKGROUND/AIMS: This study aims to define factors associated with ALT elevation in candidates for blood donation, to evaluate ALT levels during follow-up, and to establish a histological diagnosis of hepatic disease. METHODS: Alcoholism, obesity, drug-induced liver disease, diabetes, hemochromatosis and alpha 1-anti-trypsin deficiency were investigated in 119 subjects (113 males, six females, aged 33.4+/-8.4 years) who were hepatitis B surface antigen/anti-hepatitis C virus negative and had been rejected as blood donors as a result of elevated ALT (>1.5 times the upper normal limit (UNL) in two determinations). During follow-up, ALT was determined every 8 weeks and liver biopsy recommended in cases with persistently elevated ALT levels. RESULTS: Obesity (30.2%) and alcoholism (28.6%) were most frequently associated with ALT elevation and in 9.2% of cases no association was found. ALT levels decreased significantly, regardless of the associated factor. Liver histology in 40 patients showed steatosis (35%), steatohepatitis (30%), non-specific reactive hepatitis (12.5% of cases), normal liver (15% of cases) and alcoholic cirrhosis, hemochromatosis and non-specific portal fibrosis in three cases. CONCLUSION: ALT levels usually dropped during follow-up and although severe hepatic lesions can be found in asymptomatic blood donors, mild hepatic damage is the rule.     

Leucocyte antibodies in blood donors and a look back on recipients of their blood components

BACKGROUND AND AIM: The role of leucocyte antibodies in donors is poorly understood in pathogenesis of transfusion-related acute lung injury (TRALI). We examined antibodies in donors and traced recipients transfused with their blood components. MATERIAL AND METHODS: Antibodies were examined in 1043 donors by five methods, look back performed in 26 recipients. RESULTS: Anti-human leucocyte antigen detected by enzyme-linked immunosorbent assay in 9.8% women but none in men. Specificities identified using FlowPRA, antibodies detected after several months. TRALI reported in one recipient from immunized donor. In 11 of 26 recipients without TRALI, cognate antigens were identified. CONCLUSION: Detection of antibodies in donors cannot predict TRALI, even in recipients with cognate antigen(s).     

台州地区无偿献血者不规则抗体筛选结果分析

目的:对本地区无偿献血者不规则抗体的筛选结果进行统计分析,为保证安全有效输注血液提供相应建议。方法:将39例不规则抗体阳性无偿献血者的性别、血型及发现途径分布进行汇总分析。结果:0.07%(27/38 687)属于IgM类抗体,0.03%(12/38 687)属于IgG类抗体;女性产生抗体的概率较男性高;不规则抗体的发生率在O型无偿献血者明显偏少,A型、B型和AB型间不规则抗体的发生率差异无统计学意义。结论:为增强临床输注的安全有效,有必要对献血者的血清或血浆进行不同类别的抗体筛查。     

柳州市无偿献血人群HIV感染者特征分析

目的了解柳州市无偿献血者HIV感染情况。方法对2008—2011年上半年无偿献血共187069份标本进行HIV传染性标志物检测,统计HIV感染率;对HIV感染者进行告知和首次随访,进行流行病学调查。结果柳州市无偿献血人群2008～2011年历年HIV感染率（1／10万）分别为52．43、75．13、57．01和52．27,累计总体感染率为60．41／10万,以男性为主,性比例为1．51：1。以20—39岁青壮年为主,占79．65％。76．99％的感染者对HIV防控知识模糊和不了解,50．44％的感染者可能的感染途径为性行为感染。结论柳州市无偿献血者HIV感染率的上升势头得到遏制,但形势仍然严峻。感染者以青壮年为主,同时也有向低龄、老龄人群发展的趋势,感染途径以性行为为主,流行模式呈多样性。     

南京市无偿献血者谷丙转氨酶检测结果分析

目的：调查献血者谷丙转氨酶（ALT）与NAT-HBV/HCV检测的相关性并探讨ALT的报废阈值。方法：使用全自动生化分析仪进行ALT检测;使用全自动酶免系统进行ELISA-HBsAg/抗-HCV检测;使用全自动病毒核酸检测系统进行NAT-HBV/HCV检测。结果：在15123名献血者中,共检出ALT不合格者657例,其中7例为ALT不合格伴有HBsAg或抗-HCV有反应性;650例为单项ALT不合格,经NAT检测其HBV-DNA和HCV-DNA均为阴性。若将ALT报废阈值提高到60U/L,献血者ALT的合格率将提高到98.36%。结论：ALT与NAT-HBV/HCV无相关性,ALT的报废阈值应适当提高。