Donation Frequency Research Articles

Don't forget the group! The importance of social norms and empathy for shaping donation behaviour.

Feelings of empathy and the influence of social descriptive norms are related to intentions to donate. People are more likely to help and donate to others when they empathise with them, and when they perceive descriptive norms to encourage such behaviour. However, previous work has not considered the potential interplay between empathy and descriptive norms. Across two surveys in two different national settings (Ns=1300 and 144), we assessed the interplay between empathy and social descriptive norms on frequency of donation (Study 1) and on willingness to donate (Study 2). Consistent with our main hypotheses, in Studies 1 and 2, norms and empathy were positive predictors of frequency of donation and willingness to donate. Importantly, a consistent interaction between norms and empathy was found in both studies. Empathy was a stronger predictor of donation behaviour and disposition when norms were low. Theoretical and applied implications of these findings are discussed.

Analysis of Causes and Condition of Blood Donation Reaction Under Collective Emergency Blood Donation

To explore the causes and specific conditions of blood donation reaction under the collective emergency unpaid blood donation, and to provide theoretical basis and decision-making reference for drafting the collective emergency unpaid blood donation and blood donation safety. Through a combination of prospective and retrospective models, and statistical methods were used to analyze the causes and conditions of the blood donation response of 10401 people participating in collective emergency unpaid blood donation during 2016.1-2018.8. A total of 10401 person-times donated blood in a sitting manner, and a total of 293 blood donation reactions occurred. By improving the blood donation services year by year, the moderate blood donation reaction during the year 2017 and 2018 was significantly lower than that in 2016 (P＜0.05). In the actual blood donation group of≤100, 200, 300 and 400 ml, the incidence of blood donation reaction was statistically significant (P＜0.05); the incidence of blood donation reaction in the blood donors for 1,2,3 and ＞3 drnations was also statistically significant (P＜0.05); the blood donation reactions rate of B antigen containers was significantly different from the donors without B antigen (P＜0.05); the incidence of blood donation reaction with related to the weight of the donor. The blood donation reaction of collective emergency unpaid blood donation closely relates with mental factors, blood donation service, blood donation frequency and body weight of the blood donor. The first blood donation is more likely to produce blood donation reaction. The blood donation volum≤ 100 ml from blood donors is resulted mostly from blood donation reactions.

Hemochromatoza pierwotna — wykorzystanie krwi pochodzącej z leczniczych krwioupustów do celów klinicznych

Many countries currently witness a decline in the number of blood donors and, consequently, a decrease in supply of blood and blood components dedicated for clinical use. To improve the situation one of the measures taken is to qualify for blood donation people with diagnosed hereditary hemochromatosis (HH) — a genetic disorder that leads to iron overload, most effectively treated by frequent bloodletting to eliminate the excess of iron. Blood from therapeutic phlebotomy is often discarded. Reservations and doubts related to the clinical use of this blood are primarily related to additional factors that affect its safety. However, there is currently no convincing evidence that blood from HH donors exposes recipients to higher risk. Reservations are also raised regarding organizational challenge and costs as well as ethical concerns regarding the voluntary nature of donations. In Poland — according to current regulations — HH individuals are deferred from donating blood during the onset of disease symptoms or in the course of treatment other than phlebotomy. The decision regarding blood donation as well as frequency of subsequent donations is made by the physician in the unit of the public health service in cooperation with the doctor responsible for therapy of hemochromatosis. Guidelines regarding this group of potential blood donors markedly differ from country to country therefore numerous publications emphasize the need to develop a set of uniform, optimal regulations based on the outcome of available research.

Seroprevalencia del virus de la hepatitis C en un banco de sangre de Medellín-Colombia, 2005-2018

El objetivo de este estudio fue estimar la seroprevalencia del virus de la hepatitis C (VHC) en donantes de un banco de sangre de Medellín- Colombia en el periodo 2005-2018 e identificar sus factores asociados. Se realizó un estudio ecológico mixto con 166603 sujetos. La descripción se realizó con frecuencias, series de tiempo con las seroprevalencias y sus intervalos de confianza del 95 %. Se estimaron razones de odds crudas y ajustadas mediante regresión logística binaria en SPSS 25.0®. La seroprevalencia fue 0,567 (IC 95 % = 0,53-0,60) con una endemia baja y estable desde el 2010. Los únicos factores que presentaron diferencias estadísticas en la seroprevalencia fueron el grupo etario y la frecuencia de donación, con una infección 23 % mayor en los donantes con edad mayor de 40 años (frente a las personas con edad entre 18-40), y 94 % mayor en los donantes de primera vez, en comparación con quienes donan a repetición . Se concluye que en Medellín los niveles endémicos del VHC han sido estables y bajos en la última década, evidenciando la importancia de la vigilancia epidemiológica que realizan los bancos de sangre. La menor prevalencia en la última década hace suponer una exposición diferencial al virus en función de la generación a la que se pertenece, de manera que el efecto de cohorte de nacimiento debe ser investigada en estudios posteriores.

Lots of little ones: Analysis of charitable donations to a hospice and palliative care unit in Taiwan.

Charitable donations play a major role in the provision of hospice and palliative care (HPC) services, most of which are not reimbursed by health insurance programs. A good understanding of the constitution and use of donations is thus conducive to maintaining a high-quality HPC unit. The data sources were the publicly available balance sheet, work report, and donor lists of a foundation exclusively supporting one of the best HPC units in Taiwan in the fiscal year of 2017. The analysis included the donation amounts and frequencies by donor type (individual, corporate, and group) and the categories of expenses. The foundation received 3033 donations worth a total of 7.8 million New Taiwan dollars (NTD) (approximately 258 thousand US dollars) in 2017. Two-thirds of the donations were allocated to the provision of direct care services. Of the 3033 donations, only 11 (0.4%) were worth 100 000 NTD or more, while 108 (3.6%) were valued between 10 000 and 99 999 NTD, 1268 (41.8%) were valued between 1000 and 9999 NTD, and 1646 (54.2%) were worth less than 1000 NTD. Of 1051 donors, 974 (92.7%) were individuals, 378 (36.0%) donated more than once, and 106 (10.1%) donated 12 or more times in one year. HPC services in Taiwan are sponsored by lots of individuals and small donations. For sustainability of standards-based and quality HPC services, the benevolence of the public should be thus cherished and adequately responded to.

Seroprevalence of human T-lymphotropic virus HTLV and its associated factors in donors of a blood bank of Medellín-Colombia, 2014-2018.

BackgroundResearch on HTLV in Colombia is limited; despite being an endemic country there are few studies on the magnitude of this infection. The aim of this study was to determine the seroprevalence of HTLV I/II and its associated factors in donors to a blood bank of Medellín Colombia, 2014–2018.MethodsThis is a cross-sectional study of 52,159 donors with a secondary information source. Seroprevalence of HTLV I/II was determined with its confidence interval and the population characteristics were described by frequency and summary measures. To explore the associated factors, Pearson’s Chi square test, Mann-Whitney U test, crude odds ratios were used and they were adjusted by logistic regression in SPSS 25.0.Results88% of the population lived in the metropolitan area, 68.5% belonged to the University. 76.2% were altruistic donors (unpaid donors who did not donate to a specific patient). 24.5% were repetitive (paid) donors. 75% of the donors were under 41 years old. The seroprevalence of HTLV I/II was 0.176% (95% CI = 0.139% -0.213%), being statistically lower in repetitive donors and men.ConclusionThe seroprevalence of HTLV I/II infection in the studied blood bank is lower than that reported in other blood banks at the departmental and national levels. In Medellín, it was associated with the frequency of donation and gender, which is useful information for the hemovigilance programs of the city.

Longer-term efficiency and safety of increasing the frequency of whole blood donation (INTERVAL): extension study of a randomised trial of 20 757 blood donors

SummaryBackgroundThe INTERVAL trial showed that, over a 2-year period, inter-donation intervals for whole blood donation can be safely reduced to meet blood shortages. We extended the INTERVAL trial for a further 2 years to evaluate the longer-term risks and benefits of varying inter-donation intervals, and to compare routine versus more intensive reminders to help donors keep appointments.MethodsThe INTERVAL trial was a parallel group, pragmatic, randomised trial that recruited blood donors aged 18 years or older from 25 static donor centres of NHS Blood and Transplant across England, UK. Here we report on the prespecified analyses after 4 years of follow-up. Participants were whole blood donors who agreed to continue trial participation on their originally allocated inter-donation intervals (men: 12, 10, and 8 weeks; women: 16, 14, and 12 weeks). They were further block-randomised (1:1) to routine versus more intensive reminders using computer-generated random sequences. The prespecified primary outcome was units of blood collected per year analysed in the intention-to-treat population. Secondary outcomes related to safety were quality of life, self-reported symptoms potentially related to donation, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin and other factors. This trial is registered with ISRCTN, number ISRCTN24760606, and has completed.FindingsBetween Oct 19, 2014, and May 3, 2016, 20 757 of the 38 035 invited blood donors (10 843 [58%] men, 9914 [51%] women) participated in the extension study. 10 378 (50%) were randomly assigned to routine reminders and 10 379 (50%) were randomly assigned to more intensive reminders. Median follow-up was 1·1 years (IQR 0·7–1·3). Compared with routine reminders, more intensive reminders increased blood collection by a mean of 0·11 units per year (95% CI 0·04–0·17; p=0·0003) in men and 0·06 units per year (0·01–0·11; p=0·0094) in women. During the extension study, each week shorter inter-donation interval increased blood collection by a mean of 0·23 units per year (0·21–0·25) in men and 0·14 units per year (0·12–0·15) in women (both p<0·0001). More frequent donation resulted in more deferrals for low haemoglobin (odds ratio per week shorter inter-donation interval 1·19 [95% CI 1·15–1·22] in men and 1·10 [1·06–1·14] in women), and lower mean haemoglobin (difference per week shorter inter-donation interval −0·84 g/L [95% CI −0·99 to −0·70] in men and −0·45 g/L [–0·59 to −0·31] in women) and ferritin concentrations (percentage difference per week shorter inter-donation interval −6·5% [95% CI −7·6 to −5·5] in men and −5·3% [–6·5 to −4·2] in women; all p<0·0001). No differences were observed in quality of life, serious adverse events, or self-reported symptoms (p>0.0001 for tests of linear trend by inter-donation intervals) other than a higher reported frequency of doctor-diagnosed low iron concentrations and prescription of iron supplements in men (p<0·0001).InterpretationDuring a period of up to 4 years, shorter inter-donation intervals and more intensive reminders resulted in more blood being collected without a detectable effect on donors' mental and physical wellbeing. However, donors had decreased haemoglobin concentrations and more self-reported symptoms compared with the initial 2 years of the trial. Our findings suggest that blood collection services could safely use shorter donation intervals and more intensive reminders to meet shortages, for donors who maintain adequate haemoglobin concentrations and iron stores.FundingNHS Blood and Transplant, UK National Institute for Health Research, UK Medical Research Council, and British Heart Foundation.

STEM CELL LIKE ERYTHROID/MEGAKARYOCYTE-PRIMED PROGENITORS EXPAND IN HUMANS IN RESPONSE TO FREQUENT PLATELET DONATION

Blood formation is maintained by a heterogeneous pool of haematopoietic stem cells and multipotent progenitors (HSC/MPPs), consisting of subsets with distinct functional behaviours and molecular make-ups. However, the contribution of different HSC subsets to adult human blood production and to the altered haematopoietic phenotypes associated with stress or disease remains unexplored. Here, we study the composition of the adult human HSC pool from the peripheral blood (PB) of healthy frequent platelet donors. We find that human phenotypic PB HSC/MPPs display heterogeneous differentiation potential in single-cell culture assays and a rare subset has long-term repopulation capacity in xenograft models. Unexpectedly a large fraction of single HSC/MPPs exclusively commits to the erythroid/megakaryocytic (Ery/Mk) lineage in vitro. These cells, which we termed “stem cell like Ery/Mk-primed progenitors” (SL-EMPPs), can be prospectively purified from phenotypic HSC/MPPs as CD71+ CD34lo and do not engraft NSG mice. Similar to multipotent HSCs, SL-EMPPs are largely quiescent, but display gene signatures indicative of increased metabolic activity. Yet, SL-EMPPs also substantially differ from classical Ery/Mk progenitors as for cell cycle status, signalling pathway activity and serial replating capacity. Strikingly, SL-EMPPs are extremely rare in haematopoietic tissues from non-platelet donors including steady-state PB, indicating an expansion of this subset in response to frequent platelet donation. Interestingly, SL-EMPPs were also detected in PB of patients with essential thrombocythemia, a disease characterised by overproduction of platelets, suggesting a potential contribution of SL-EMPPs to blood disorders. In conclusion, our results identify the cellular route by which, in humans, stress-induced chronic platelet overproduction is mediated directly from the HSC compartment.

Iron status and risk factors for iron depletion in a racially/ethnically diverse blood donor population.

The optimal approach for reducing iron depletion (ID) in blood donors may vary depending on biologic or behavioral differences across donors. More than 12,600 successful whole blood donors were enrolled from four US blood centers for ferritin testing. The study population was enriched for racial/ethnic minorities (1605 African American, 1616 Asian, 1023 Hispanic). Subjects completed questionnaires on ID risk factors. Logistic regression identified predictors of absent iron stores (AIS; ferritin <12 ng/mL) and low ferritin (LF; ferritin <26 ng/mL). Across all subjects, 19% had AIS and 42% had LF, with a sharp increase in risk observed with increasing donation intensity and among women a large decrease in risk in those more than 50 years old. When other factors were controlled for, African American and Asian donors showed 20% to 25% decreased risk for AIS compared to non-Hispanic Caucasian donors, while Hispanic donors had 25% higher risk. Daily iron supplementation reduced risk for LF and AIS by 30% to 40%, respectively, while the benefit from less frequent use was lower (7%-19% protection). Regular antacid use was associated with at least 20% increment to risk. Use of oral contraceptives or estrogen in females reduced risk by 16% to 22%, while males who reported supplemental testosterone use had a 50% to 125% greater risk for LF and AIS. This study confirms high prevalence of LF and AIS in US donors and the principal risk factors of age, sex, and donation frequency. Additional demographic and behavioral risk factors of secondary importance might allow for refinement of ID mitigation strategies.

Donor protection: Iron supplementation for frequent blood donors in Korea

ObjectiveThis study aimed to evaluate the effect of oral iron supplementation in frequent donors in Korea, based solely on donation history. Study designThe hemoglobin (Hb) level, ferritin level, soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), and transferrin saturation of frequent donors at high risk for iron deficiency were compared to those of first donors. The frequent donors took iron supplements for 4 weeks and the same tests were repeated after 2 and 4 weeks to evaluate their effects. ResultA total of 53 male and 57 female frequent donors were recruited. After 4-week iron supplementation, among the men, the prevalence of a: low Hb level (<13.0 g/dL) decreased from 25% to 2%; low ferritin level (<15.0 ng/mL) decreased from 58% to 4%; iron deficient erythropoiesis (IDE) (log(sTfR/ferritin) ≥ 2.07) decreased from 77% to 33%. Among the women, the percentage of a: low Hb level (<12.0 g/dL) decreased from 44% to 9%; low ferritin level decreased from 79% to 11%; IDE decreased from 95% to 47%. In total, 15 male (28.3%) and 29 female (56.9%) blood donors reported undesirable side effects related to iron supplementation. No serious adverse events were reported. ConclusionFerritin level, a reliable indicator of iron status, increased and IDE decreased significantly after four-week iron supplementation in the female, but not in the male, donor group, compared to those of control donors. Four-week oral iron supplement was not enough to restore iron storage level in the male donor group.

Severe CD4+ T-cell lymphopenia is not observed in frequent plateletpheresis donors collected on the Fenwal Amicus.

In a recent study, we determined that 30% of frequent plateletpheresis donors collected using the Trima Accel Automated Blood Collection System (Terumo BCT) had a CD4+ T-cell count below 200 cells/μL. Whether CD4+ T-cell lymphopenia is associated with donation using other plateletpheresis instruments is unknown. We obtained blood samples from 30 current frequent Fenwal Amicus plateletpheresis donors. All participants had made 20 to 24 plateletpheresis donations in the most recent 365-day period, and all had previously donated over 50 times on the Fenwal Amicus instrument. Blood samples were analyzed to determine blood counts, including CD4+ and CD8+ counts. Of 30 study participants, none had a CD4+ count below 200 cells/μL. There was one participant with a CD4+ count between 200 and 300 cells/μL. This individual was over the age of 55 and had a history of more than 300 lifetime plateletpheresis sessions. One participant had a CD8+ count below the lower limit of normal (125 cells/μL) and a normal CD4+ count. We did not detect severe CD4+ lymphopenia in frequent platelet donors undergoing plateletpheresis with the Fenwal Amicus. Since the Fenwal Amicus does not incorporate a leukoreduction system chamber, this finding supports the hypothesis that such chambers-found in the Trima Accel instrument-contribute to CD4+ lymphopenia in frequent platelet donors.

Iron supplementation by blood donors: demographics, patterns of use, and motivation.

Iron supplements reduce the risk of iron depletion in blood donors. Recent initiatives have sought to increase use of donor iron supplementation (IS), but a baseline description of blood donor supplement practices is needed. Presenting blood donors received a questionnaire inquiring about IS beginning in December 2015. Responses were linked to operational donor information and analyzed by multivariable statistics. During the first 6 months, 53,989 evaluable responses were obtained from 80% of presenting donors. Overall, donors of 21.4% of units reported taking iron as a multivitamin (14.6%), in a separate iron supplement (4.1%), or both (2.6%). IS use was associated with female sex (27% vs. 16% in males), increasing age (30% of donors 60+ vs. 8% in 17- to 25-year-olds), and more frequent previous donations (33% in those with 6+ units donated vs. 7% in first-time donors). Multivariable logistic regression models stratified by sex indicated that donation frequency was most strongly associated with IS in females, and age most strongly associated with IS in males. Motivation for IS varied by type, with more than 75% of donors taking multivitamins with iron naming "General health and wellness," while donors taking a separate iron supplement predominantly listed motivations related to blood donation. A strong majority of blood donors report not using supplemental iron. Most donors with IS used multivitamins with iron and listed support of general health rather than blood donation as their motivation for taking iron. Effective communication of the importance of iron for blood donation is needed.

Frequency and outcomes of kidney donation from intensive care patients with acute renal failure requiring renal replacement therapy.

Kidney transplantation is the preferred treatment for end-stage renal failure. Unfortunately, donor organ shortages prevent many individuals receiving a renal transplant and there is a need to increase the pool of appropriate donors. The presence of acute kidney injury (AKI) in deceased donors has traditionally been a relative contraindication to renal transplantation, even though renal recovery may be favorable in the absence of chronic renal disease. We undertook an 8 years retrospective observational study of potential deceased organ donors with AKI requiring renal replacement therapy (RRT). We evaluated the rate of successful transplantation as well as short term and outcomes at a median of 19.5 (13.0-52.7) months after donation. Amongst 1058 consented potential organ donors, 39 patients had AKI requiring RRT, of which 19 became donors (13 not medically suitable, 7 did not proceed to donation). The median (interquartile range (IQR)) donor age was 41 (34-50) years and norepinephrine, epinephrine and vasopressin were given to 18, 14 and 9 donors, respectively. From the 38 donated kidneys 34 were transplanted. The median (IQR) age of recipients was 53 (42.8-58.5) years and they were dialysis free in a median (IQR) of 5.5 (2.3-10.8) days. Only minor abnormalities were found at 3 and 6 months renal biopsies, and two patients experienced graft failure in the first 12 months. Amongst deceased donors with AKI receiving RRT and vasoactive medications outcomes of renal transplantation seems acceptable in the absence of pre-existing renal failure and other donor co-morbidity. Such patients may be an important additional source of kidney donation.

Attitudes of blood donors to their sample and data donation for biobanking

Modern biomedical and genetic studies require large study cohorts; blood donors have been suggested to represent an appropriate group for recruiting healthy cohorts. The Blood Service Biobank (BSB) in Finland was recently established to recruit blood donors willing to give broad biobank consent. The aim of the present study is to understand how the blood bank context influences views on donating samples and health data. We organised 61 interviews and 10 group discussions with current and potential blood donors. Using qualitative content analysis, we identified three discussion frameworks that summarise the results. We found that frequent blood donors associated the voluntary act of donation with caring for patients. The blood donation experience was considered to accommodate biobank participation, but also allowed critical observations on the integration of research data collection into blood donation. Research participants identified an important difference between the blood bank and biobank contexts. In the biobank context, the focus shifts from donating blood to patients into donating personal and genetic data for research use. Blood donors’ anxiety over data use was balanced with their experience of the trustworthiness of the Blood Service. These experiences indicated that the new biobanking activity could be trusted to a familiar organisation. To build donors’ trust, biobanks should invest in their institutional reputation, donor experience and dialogue with donors. These findings can be applied to other institutions that are considering setting up biobanks with broad consent for personal data use.

In search of stool donors: a multicenter study of prior knowledge, perceptions, motivators, and deterrents among potential donors for fecal microbiota transplantation

ABSTRACTFecal microbiota transplantation (FMT) is a highly effective therapy for recurrent Clostridioides difficile infection. Stool donors are essential, but difficult to recruit and retain. We aimed to identify factors influencing willingness to donate stool. This multi-center study with a 32-item questionnaire targeted young adults and health care workers via social media and university email lists in Edmonton and Kingston, Canada; London and Nottingham, England; and Indianapolis and Boston, USA. Items included baseline demographics and FMT knowledge and perception. Investigated motivators and deterrents included economic compensation, screening process, time commitment, and stool donation logistics. Logistic regression and linear regression models estimated associations of study variables with self-assessed willingness to donate stool. 802 respondents completed our questionnaire: 387 (48.3%) age 21-30 years, 573 (71.4%) female, 323 (40%) health care workers. Country of residence, age and occupation were not associated with willingness to donate stool. Factors increasing willingness to donate were: already a blood donor (OR 1.64), male, altruism, economic benefit, knowledge of how FMT can help patients (OR 1.32), and positive attitudes towards FMT (OR 1.39). Factors decreasing willingness to donate were: stool collection unpleasant (OR 0.92), screening process invasive (OR 0.92), higher stool donation frequency, negative social perception of stool, and logistics of collection/transporting feces. We conclude that 1) blood donors and males are more willing to consider stool donation; 2) altruism, economic compensation, and positive feedback are motivators; and 3) screening process, high donation frequency, logistics of collection/transporting feces, lack of public awareness, and negative social perception are deterrents. Considering these variables could maximize donor recruitment and retention.

Effect of Frequency of Platelet Apheresis on Coagulation Function in Donors: A Prospective Cohort Study

The maximum number of plateletpheresis donation was permitted up to 24 times every year for each donor in China. This study was investigated the effect of donation frequency on coagulation function of the plateletpheresis donors. A total of 96 plateletpheresis regular donors (splitted into A, B, C groups with 32 donors each group. A was 6–11 times donations, B with 12–17 times and C with 18–24 times) and 32 first time plateletpheresis donors (D group) were analyzed. The coagulation reaction time (R), blood clot formation time (K), α-Angle, normal maximum amplitude (MA) were tested using thromboelastography instrument. Platelet (PLT) count was measured using a hematology analyzer. The ratio of the male to female were 23:9, 24:8, 27:5 and 24:8, the mean age were 40.7 ± 7.6, 39.8 ± 8.3, 40.2 ± 7.9 and 37.0 ± 9.3, and the platelet collection amount were 1.55 ± 0.37 U, 1.58 ± 0.38 U, 1.61 ± 0.33 U and 1.46 ± 0.31 U in the A, B, C, D groups respectively. There were significant difference in the values of the R, K, α-Angle, MA and PLT count between before and after plateletpheresis donation in each group (p < 0.05). However, the values of R, K, α-Angle, MA and PLT count in the before donation were not difference among the A, B, C, D groups (p > 0.05). Similar results were found in the after plateletpheresis donation. The number of the PLT was significantly correlated with the values of the R, K, α-Angle and MA (p < 0.05). However, the frequency of plateletpheresis were not significantly correlated with R, k, α and MA parameters (p > 0.05) using Spearman correlation analysis. The regular donation of apheresis platelets and the frequency of annual blood donation had no adverse effect upon coagulation function of the donors in China.

Blood donation from 2006 to 2015 in Zhejiang Province, China: annual consecutive cross-sectional studies

ObjectivesTo describe the basic demographical characteristics of whole blood donors in Zhejiang Province, China, from 2006 to 2015 and to examine the trends in individual characteristics associated with blood donation...

Induction of HCV-specific cell response in vitro by dendritic cells generated with interferon-α

The induction of a strong multi-epitope T-cell response against hepatitis C virus (HCV) plays an important role in eliminating the virus, whereas adoptive response deficiency contributes to chronic and rapid progression of HCV-infection. Since dendritic cells (DCs) are capable of priming naive T lymphocytes and induce an effective immune response, the use of DC-based vaccines to enhance the HCV-specific T cell response is considered as a new approach to treatment of chronic hepatitis C (CHC). The ability of DCs generated from monocytes in the presence of interferon- and loaded with recombinant HCV proteins Core (1120) and NS3 (11921457) to induce an antigen-specific cellular response in healthy donors and patients with CHC was investigated. The immune response was assessed by proliferative activity and Th1 (IFN)/Th2 (IL-4, IL-6) production in mononuclear cells (MNC) cultures, and activation of cytotoxic T-lymphocytes in the degranulation test. We demonstrated that the primary antigen-specific response in MNC cultures of seronegative donors was detected better by stimulation of DCs, loaded with both antigens (DCCore /NS3) than when loaded with a single protein. DCCore/NS3 induced the proliferative response and degranulation of CD8+ T cells in MNC cultures of all tested donors, and in 50% (5/10) cases IFN production. Similarly to donor DCs, DCCore/NS3 of patients with CHC induced a proliferative response in most cases (86%) and IFN production in 57% cases. At the same time, the activation of cytotoxic T cells in patients was less frequent (patients vs donors 57 and 100%, respectively), which could be partly due to increased spontaneous degranulation of CD8+ T cells in some patients. The obtained data testify the possibility of using vaccines based on interferon--induced DCs for the prevention and treatment of chronic HCV infection.

CD4+ T-cell lymphopenia in frequent platelet donors who have ceased platelet donation for at least 1 year.

We recently discovered that 30% of current frequent apheresis platelet donors in a study at our donor center had CD4+ counts below 200 cells/μL. How long CD4+ lymphopenia persists after ceasing plateletpheresis is unknown. Whether there are infectious or other complications in former frequent donors that could relate to CD4+ lymphopenia is also unknown. We mailed a letter to former frequent apheresis platelet donors who had not donated platelets for at least 12 months. Frequent donation was defined as 20 to 24 plateletpheresis sessions in at least one 365-day period starting in 2011. Donors who expressed interest in the study were contacted to schedule a study visit. Participants in the study provided a blood sample and completed a health questionnaire that included questions about opportunistic infections and malignancies. Of 50 potential study candidates who were mailed a letter, 15 participated in the study. There were 2 participants with CD4+ counts below 200 cells/μL, one of whom had prior counts that documented a small improvement with cessation of plateletpheresis. Three participants had counts between 200 and 300 cells/μL. No study participant had a history of an opportunistic infection or a malignancy associated with immune dysregulation. We detected CD4+ lymphopenia in former frequent apheresis platelet donors who had ceased platelet donation for more than 1 year. There was no evidence that the CD4+ lymphopenia predisposes to opportunistic infections or to malignancies associated with immune dysregulation.

Plateletpheresis-associated lymphopenia in frequent platelet donors

AbstractMore than 1 million apheresis platelet collections are performed annually in the United States. After 2 healthy plateletpheresis donors were incidentally found to have low CD4+ T-lymphocyte counts, we investigated whether plateletpheresis causes lymphopenia. We conducted a cross-sectional single-center study of platelet donors undergoing plateletpheresis with the Trima Accel, which removes leukocytes continuously with its leukoreduction system chamber. We recruited 3 groups of platelet donors based on the total number of plateletpheresis sessions in the prior 365 days: 1 or 2, 3 to 19, or 20 to 24. CD4+ T-lymphocyte counts were <200 cells per microliter in 0/20, 2/20, and 6/20 donors, respectively (P = .019), and CD8+ T-lymphocyte counts were low in 0/20, 4/20, and 11/20 donors, respectively (P < .001). The leukoreduction system chamber's lymphocyte-extraction efficiency was ∼15% to 20% for all groups. Immunophenotyping showed decreases in naive CD4+ T-lymphocyte and T helper 17 (Th17) cell percentages, increases in CD4+ and CD8+ effector memory, Th1, and regulatory T cell percentages, and stable naive CD8+ and Th2 percentages across groups. T-cell receptor repertoire analyses showed similar clonal diversity in all groups. Donor screening questionnaires supported the good health of the donors, who tested negative at each donation for multiple pathogens, including HIV. Frequent plateletpheresis utilizing a leukoreduction system chamber is associated with CD4+ and CD8+ T-cell lymphopenia in healthy platelet donors. The mechanism may be repeated extraction of these cells during plateletpheresis. The cytopenias do not appear to be harmful.