Gender differences in presentation rates, deferrals and return behaviour among Norwegian blood donors.

BACKGROUND AND OBJECTIVES: Women are under-represented among long-term blood donors. Reasons for this were sought in the donor pool of the Blood Bank of Oslo, Norway, which comprises only voluntary, non-remunerated donors and has a high degree of stability. METHODS: Three sources of data were analyzed: (1) the subsequent six-year donation patterns of 17 812 donors who donated at least once in 1999; (2) reasons for pre-donation deferral of 484 prospect donors in 2004; (3) reasons for deferrals and absence during a 6.5-year period, retrieved from a follow-up study of 1029 donors who took part in a questionnaire study on motivation for blood donation in 2000. RESULTS: Women were over-represented among first-time donors and under-represented among regular donors. Women below the age of 45 years in 1999 were less likely than men to donate regularly throughout the 6-year study period, whereas the donation behaviour of women and men above 45 years of age was similar. Young (18-29 years) female prospect donors were more frequently deferred at first-time donation than males. In the 6.5-year follow-up study, pregnancy was the most frequently reported cause of absence from or termination of donation, and was reported by 32% of the female respondents that were 45 years or younger. Among the donors that reported having been pregnant, 42% stated to have resumed donation and < 4% stated that they no longer were blood donors. Reported termination of donation by female donors was associated with reported practical obstacles and discomfort related to donation, but not with loss of motivation. CONCLUSION: Most of the gender differences in donation patterns could be ascribed to absence because of pregnancy and lactation. Practical problems and discomfort during donation were important reasons why women reported to have stopped donation. Current deferral criteria pose problems for the recruitment and retention especially of young women.

Recruiting and retaining young people as voluntary blood donors.

OBJECTIVES: Reasons for predonation deferral of young potential donors and prospects of recruiting and retaining young people (age 18-29) as voluntary blood donors were studied. STUDY DESIGN AND METHODS: Three different sources of data were analysed: (i) the subsequent donation history of 2057 donors who started their donation career at the Blood Bank of Oslo (BBO) in 1999, age and gender of all new donors accepted for donation at BBO in 2004 was retrieved from electronic data files; (ii) data on reasons for predonation deferral, age and gender of all deferred prospect donors at BBO in 2004 was obtained from original screening questionnaires; and (iii) results from a national telephone survey of the general population's attitudes regarding blood donation, conducted in 2005. RESULTS: Twenty-five per cent of the first-time donors recruited in 1999 remained active in 2005, but the percentage was higher among older than younger donors. Change of residency was the most frequent reason for termination of donation among young donors. Young prospect donors were more frequently than older ones deferred for lifestyle-related reasons. Prospect donors older than 30 years were more frequently deferred for health-related reasons. A large proportion (57.7%) of young adults reported a favourable attitude towards becoming blood donors. Lack of a personal request (not being asked) was the most frequently reported reason for not giving blood among young people with no donation record. Only a minor proportion of young non-donors considered themselves disqualified from donating blood due to health status. CONCLUSIONS: Lifestyle-related eligibility criteria and changes of residency pose problems for recruitment and retention of young donors. However, a large proportion of young adults state that they are able and willing to donate blood; therefore, the prospects of recruiting young people as voluntary blood donors seem generally positive.

Motivation, recruitment and retention of voluntary non-remunerated blood donors: a survey-based questionnaire study.

BACKGROUND AND OBJECTIVES: The aim of this study was to establish which motivational and socio-demographic factors are important for the development of a long-term commitment as a voluntary, non-remunerated blood donor. STUDY DESIGN AND METHODS: A cross-sectional sample survey of active blood donors in Oslo, Norway, was conducted. Donors filled in a self-administered questionnaire during donation. Data on motivation were analysed using factor analysis. RESULTS: The blood donors' socio-demographic characteristics were found to be similar to those of the population as a whole. The single, most important, recruitment channel was the influence of active blood donors. Five dimensions of blood-donor motivation were identified with factor analysis. These were: altruism and empathy; social reasons (such as the influence of friends and family); strengthening of one's self-esteem; positive experiences associated with donation; and a moral obligation to donate. Support for statements on altruistic motives for donation was strong and similar in long-time and short-time donors. In contrast, short-time donors were more likely to be motivated by factors related to self-esteem than were long-term donors. CONCLUSION: The 'good habit' of continued blood donation seems not to be exclusively linked to a high degree of reported other-regarding ('altruistic') reasons, but also to a combination of motives, including some modestly self-regarding motives.

Levels of ochratoxin A in blood from Norwegian and Swedish blood donors and their possible correlation with food consumption.

Blood levels of ochratoxin A were determined in 406 Scandinavian blood donors (206 from Oslo, Norway, and 200 from Visby on the island of Gotland, Sweden), using an HPLC method. In connection with the blood collection, the subjects were asked to fill in a food questionnaire to obtain individual dietary information relevant to ochratoxin A exposure. The mean plasma level of ochratoxin A was 0.18 ng/ml in Oslo and slightly higher, 0.21 ng/ml (P=0.046) in Visby. There was no correlation between plasma levels of ochratoxin A and the estimated total dietary intake of ochratoxin A based on consumption data and levels in food (retrieved from the literature), neither was the plasma level of ochratoxin A correlated with the total amount of food consumed. However, consumption of several foods, including cereal products, wine, beer and pork, were to some minor degree related to high plasma levels of ochratoxin A. The strongest correlations (correlation coefficient r>0.4; P<0.001) were observed for women in relation to the consumption of beer or medium brown bread. Correlation analysis of combinations of two or more food categories did not result in any statistically significant correlation.

Risk behaviour among blood donors who give blood in order to be tested for the human immunodeficiency virus.

BACKGROUND AND OBJECTIVES: There has been concern that some individuals may donate blood primarily motivated by the easy access to human immunodeficiency virus (HIV) testing, and that such donors may represent a risk to the transfusion service. In this article we focus on the risk behaviour of donors who reported that they gave blood in order to be HIV tested. MATERIALS AND METHODS: Anonymous questionnaires were given to 5859 blood donors. The response rate was 70%. RESULTS: Of the responders, 2.8% reported to have donated blood in order to be HIV tested. However, 87% of the donation-for-test group did not have any identified risk behaviour. CONCLUSIONS: The proportion who donated blood in order to be HIV tested was higher than expected, but the majority of the group did not have any identifiable HIV risk.

mtDna and the islands of the North Atlantic: estimating the proportions of Norse and Gaelic ancestry.

A total of 1,664 new mtDNA control-region sequences were analyzed in order to estimate Gaelic and Scandinavian matrilineal ancestry in the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye and to investigate other aspects of their genetic history. A relative excess of private lineages in the Icelanders is indicative of isolation, whereas the scarcity of private lineages in Scottish island populations may be explained by recent gene flow and population decline. Differences in the frequencies of lineage clusters are observed between the Scandinavian and the Gaelic source mtDNA pools, and, on a continent-wide basis, such differences between populations seem to be associated with geography. A multidimensional scaling analysis of genetic distances, based on mtDNA lineage-cluster frequencies, groups the North Atlantic islanders with the Gaelic and the Scandinavian populations, whereas populations from the central, southern, and Baltic regions of Europe are arranged in clusters in broad agreement with their geographic locations. This pattern is highly significant, according to a Mantel correlation between genetic and geographic distances (r=.716). Admixture analyses indicate that the ancestral contributions of mtDNA lineages from Scandinavia to the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye are 37.5%, 35.5%, 11.5%, and 12.5%, respectively.

Risk behavior in Norwegian blood donors.

BACKGROUND: Blood banks ensure the safety of blood components by testing them for a set of known infectious agents and by careful selection of donors based on a self-administered questionnaire and an interview. The purpose of this study is to describe the risk behavior for sexually transmitted diseases in Norwegian blood donors. STUDY DESIGN AND METHODS: A survey of the sexual habits of 5,859 blood donors in the capital of Norway was performed by using anonymous questionnaires. The results were compared with a previous survey of 10,000 randomly selected Norwegian subjects aged 18 to 60 years. The response rates were 70.3 percent and 48.4 percent, respectively. RESULTS: Blood donors had considerably more education than the general population. Their general sexual behavior was similar to that of the rest of the population, although the blood donors had later sexual debut, fewer new partners per year, and a lower frequency of intercourse. In addition, homosexual experience among males was much lower in the donor group. Blood donors were less likely to engage in risk behavior for sexually transmitted diseases than were the general population. Nevertheless, 1.5 percent of the donors reported behavior that would have led to deferral had the behavior been disclosed at the predonation interview. Deferrable donors were more likely to be male and young and to have had many partners. CONCLUSION: Anonymous questionnaires reveal information that is not given at the time of blood donation.

Estimating Scandinavian and Gaelic ancestry in the male settlers of Iceland.

We present findings based on a study of Y-chromosome diallelic and microsatellite variation in 181 Icelanders, 233 Scandinavians, and 283 Gaels from Ireland and Scotland. All but one of the Icelandic Y chromosomes belong to haplogroup 1 (41.4%), haplogroup 2 (34.2%), or haplogroup 3 (23.8%). We present phylogenetic networks of Icelandic Y-chromosome variation, using haplotypes constructed from seven diallelic markers and eight microsatellite markers, and we propose two new clades. We also report, for the first time, the phylogenetic context of the microsatellite marker DYS385 in Europe. A comparison of haplotypes based on six diallelic loci and five microsatellite loci indicates that some Icelandic haplogroup-1 chromosomes are likely to have a Gaelic origin, whereas for most Icelandic haplogroup-2 and -3 chromosomes, a Scandinavian origin is probable. The data suggest that 20%-25% of Icelandic founding males had Gaelic ancestry, with the remainder having Norse ancestry. The closer relationship with the Scandinavian Y-chromosome pool is supported by the results of analyses of genetic distances and lineage sharing. These findings contrast with results based on mtDNA data, which indicate closer matrilineal links with populations of the British Isles. This supports the model, put forward by some historians, that the majority of females in the Icelandic founding population had Gaelic ancestry, whereas the majority of males had Scandinavian ancestry.

Prevalence of hemochromatosis among first-time and repeat blood donors in Norway.

BACKGROUND/AIMS: The observed prevalence of hemochromatosis has ranged considerably from 0.05 to 0.37% in studies requiring liver biopsy. We aimed to study the prevalence of genetic hemochromatosis among Norwegian blood donors. METHODS: We studied 10,552 healthy blood donors (5312 women and 5240 men) using serum ferritin as a screening parameter. If serum ferritin concentration was > or = 100 micrograms/l in women and > or = 200 micrograms/l in men, serum iron and transferrin (measured as total iron binding capacity = TIBC) were measured. Blood donors who repeatedly had a transferrin saturation above 40% and a ferritin concentration above these limits were referred to a hepatologist (H.B.). RESULTS: Serum ferritin was > or = 100 micrograms/l in 94/5312 (1.8%) women and > or = 200 microliters in 79/5240 (1.5%) men. Of these, 37 persons had a serum ferritin concentration above 100 micrograms/l (females) or above 200 micrograms/l (males) and a transferrin saturation above 40%. Nineteen of them (13 men and 6 women, median age 36 years, range 28-68) were identified as having hemochromatosis on the basis of increased hepatic iron index. Serum ferritin ranged from 111 to 1980 micrograms/l (median 357 micrograms/l and transferrin saturation from 50 to 100% (median 92%), hepatic iron from 48 to 471 mumol/g dry weight (median 118 mumol/g) and hepatic iron index from 1.5 to 12.1 (median 3.0). One person had cirrhosis and none had diabetes. The prevalence of hemochromatosis was significantly higher among first-time blood donors (12 out of 3500 [3.4/1000]) compared with repeat donors (7 out of 7052 [1/1000]), p < 0.005. CONCLUSIONS: The observed prevalence of hemochromatosis in Norwegian first-time blood donors of 0.34% is comparable to recently observed prevalences in other studies. However, the use of serum ferritin as a first-step screening tool may have failed to detect hemochromatosis in the early stage where iron overload has not yet occurred.

Alterations in lymphocyte subsets in blood may predict resectability in carcinoma of cardia or oesophagus.

Impaired immune responses in patients with carcinoma of cardia or oesophagus have previously been reported. However, we do not know whether resectability correlates with specific immunological variables. Immunological assessment was performed in 35 such cancer patients including measurement of total T cells (CD3+) and T cell subsets (CD4+ and CD8+), NK cells (CD16+) and B cells (CD19+) in blood. In vitro lymphocyte responses to phytohemagglutinin (PHA) separated from peripheral blood were quantitated. The numbers in peripheral blood of both total T cells (CD3+) and B lymphocytes (CD19+) were significantly lower in the inoperable patients compared to resected patients (P < 0.01). The number of NK cells (CD16+) was, however, not significantly lower in the inoperable patients compared to the patients operated for cure. Lymphocyte responses to PHA in vitro were similar in resectable and non-resectable patients, but significantly lower in inoperable patients compared to the controls (P < 0.01). In conclusion, resectability in carcinoma of cardia or oesophagus is associated with changes in both T (CD3+) and B (CD19+) cell subsets.

Susceptibility to develop celiac disease is primarily associated with HLA-DQ alleles.

We have recently reported that the susceptibility to develop celiac disease (CD) seems to be primarily associated to a particular combination of an HLA-DQA1 (DQA1*0501) and an HLA-DQB1 (DQB1*0201) allele: i.e., a particular DQ alpha/beta heterodimer. To investigate whether certain DP alleles might also contribute to the genetic susceptibility, DPA1 and DPB1 genes of 94 CD patients and 132 healthy controls were examined by probing in vitro amplified DNA with sequence-specific oligonucleotide probes corresponding to all hitherto known DPA1 and DPB1 alleles. The frequencies of the DPA1*0201 and of the DPB1*0101 alleles were increased in CD patients compared to healthy controls (0.31 versus 0.14 and 0.25 versus 0.08, respectively). However, these DP alleles were in linkage disequilibrium with CD-associated DQ alleles in the normal population, and the difference in frequency of these DP alleles was no longer significant when CD patients and healthy controls carrying the CD-associated DQA1*0501 and DQB1*0201 alleles were compared. DQB1*0201 homozygous individuals were overrepresented among DQB1*0201-positive patients compared to controls. When DQB1*0201 heterozygous patients and controls were compared, nearly identical frequencies of the DPA1*0201 and the DPB1*0101 alleles were found. Thus, the observed increase of the DPA1*0201 and DPB1*0101 alleles among CD patients seems mainly to be caused by linkage disequilibrium to the CD-associated DQ alleles.

Specificity of two subsets of cytotoxic human gamma delta T-cell clones.

Peripheral blood mononuclear cells were enriched for gamma delta T cells by immunomagnetic separation, stimulated with cells from an allogeneic donor, and cloned. T-lymphocyte clones (TLC) of the two major gamma delta T-cell subsets, BB3+ (i.e. V delta 2+) and delta TCS1+ (i.e. V delta 1/(D)/J delta 1), were obtained. In addition, one gamma delta TLC was BB3- delta TCS1-. All of the BB3+ TLC showed strong cytotoxicity against various allogeneic tumor cell lines, such as Daudi and K562. The cytotoxicity against the tumour cell lines was modulated by MoAb against the gamma delta TcR. The BB3+ TLC were not cytotoxic against B-lymphoblastoid cell lines (B-LCL). In contrast, the delta TCS1+ TLC showed much lower cytotoxic activity against the tumour cell lines, but many were strongly cytotoxic against allogeneic B-LCL. Some of the delta TCS1+ TLC demonstrated HLA-specific cytotoxicity, while other delta TCS1+ TLC had a more broad cytolytic activity against B-LCL. Thus, the two major subtypes of gamma delta T cells from this donor, as defined by MoAb BB3 and delta TCS1, were distinct with respect to recognition specificity.

Recognition of a particular HLA-DQ heterodimer by a human gamma/delta T cell clone.

Peripheral blood mononuclear cells from a single donor were depleted of T cell receptor (TcR) alpha/beta T cells, stimulated with allogeneic cells, and gamma/delta T lymphocyte clones (TLC) were isolated by limiting dilution. Five TLC were cytotoxic against B-lymphoblastoid cell lines from the stimulating cell donor, and demonstrated a restricted allospecificity in panel cell studies. One of these, gamma/delta TLC RNG-135, was studied in more detail. Its phenotype was CD3+ TcR alpha/beta - TcR gamma/delta + BB3- delta TCS1+ CD4- CD8-. Inhibition experiments using monoclonal antibodies indicated that the cytotoxicity of TLC RNG-135 was mediated through the TcR gamma/delta, and directed against an HLA-DQ molecule. In extended panel cell experiments, this gamma/delta TLC only lysed cells carrying the DQA1*0501 and DQB1*0301 genes, either in cis position (on the DR5, DQw7 haplotype), or in trans position (the donor of the stimulating cells, DR3,4; DQw2, w7). Thus, it appears that gamma/delta T cells may recognize a particular HLA-DQ alpha/beta heterodimer, which may be encoded by DQA1 and B1 genes both in cis and trans position.

T-cell recognition of HLA class II molecules induced by gamma-interferon on a colonic adenocarcinoma cell line (HT29).

HLA class II molecules may be induced on non-lymphoid cells by gamma-interferon (IFN-gamma). We investigated if HLA class II molecules induced by IFN-gamma on the HT29 colonic carcinoma cell line are functional, i.e. if they may be recognized by allogeneic T cells. We found that IFN-gamma-treated HT29 (HT29IFN) cells could not induce primary proliferative responses of peripheral blood T lymphocytes, nor were they able to induce proliferation in T-lymphocyte clones (TLC) specific for HLA class II molecules found on HT29IFN. However, in the presence of exogenous interleukin 2 (IL-2), 1 of 5 DQw8-specific TLC proliferated when restimulated with HT29IFN, and 3 of these 5 TLC could very effectively inhibit the growth of HT29IFN, probably due to a cytotoxic effect. Both the proliferative response and the cytotoxicity were inhibited by anti-DQ MoAb. We conclude that T cells may recognize HLA-DQ molecules on non-lymphoid cells, which may be of relevance for autoimmune diseases, graft-versus-host disease, and possibly for the recognition of malignant cells.

Immunomagnetic separation of infiltrating T lymphocytes from brain tumors.

Tumor-infiltrating lymphocytes (TIL's) were isolated from human glioma biopsy specimens by immunomagnetic separation using T cell-specific monoclonal antibodies coupled to paramagnetic beads, and were expanded in culture with feeder cells and interleukin-2 (IL-2). The infiltrating cells from five of seven patients proliferated in culture. When tested after 2 to 3 weeks of culture, virtually all of the cells stained with antibodies against the CD2 and CD3 antigens. Most cells also expressed human leukocyte antigen class II molecules, while varying percentages of cells stained with antibodies against the IL-2 receptor and the CD4 and CD8 antigens. The cytotoxicity of the cultured TIL's against autologous and allogeneic glioma cells and the K562 and Daudi cell lines was measured and compared with that of lymphokine-activated killer (LAK) cells from the same patients. None of the TIL's showed significant cytotoxicity against these targets, whereas LAK cells lysed all of the targets.

T lymphocytes in human gut epithelium preferentially express the alpha/beta antigen receptor and are often CD45/UCHL1-positive.

A revived interest in intraepithelial lymphocytes (IEL) has been elicited by several recent reports suggesting that murine and avian intestinal epithelium contains mainly CD3+CD8+ cells expressing the gamma/delta T-cell receptor (TcR) for antigen; this contrasts with systemically distributed T cells which preferentially employ the TcR alpha/beta. An anatomical dichotomy in the distribution of these two T-cell lineages has hence been proposed. Here we report that this concept does not hold true in man. In situ studies with monoclonal TcR-framework antibodies showed that most (70-90%) human intestinal IEL (which are mainly CD3+CD8+) expressed TcR alpha/beta. Moreover, almost half of the intraepithelial CD3+ cells were positive for the smallest (180 kDa) CD45 molecule (UCHL1); this probably reflected that they are antigen-primed and thus represent traditional CD3+CD8+ alpha/beta+ memory T cells.

Human T lymphocyte clones: influence of culture conditions and optimization of proliferative assays.

Many CD4+ human T lymphocyte clones (TLC) are found not to proliferate against appropriate stimulating cells, and many lose this capacity during culture. This may be due, not to a defect in the recognition of the antigen, but to an inability to produce sufficient amounts of interleukin 2 (IL-2) for autocrine growth, since specific HLA-restricted proliferative responses could be induced in 'non-proliferative' clones by the addition of exogenous IL-2 or phorbol myristate acetate (PMA). Of various factors tested during expansion procedures of the clones, the proliferative capacity could only be restored by changing the stimulatory cells from B lymphoblastoid cell lines (B-LCL) to peripheral blood mononuclear cells (PBM). The cytotoxicity of the TLC was found to be independent of its proliferative capacity. After restoration of the proliferative capacity, a mouse B lymphoma cell line transfected with the appropriate HLA DQA and DQB genes was still not able to induce proliferation in the absence of exogenous IL-2. We conclude that (1) 'non-proliferative' TLC may recognize their targets, but fail to proliferate due to temporary lack of IL-2 production, and (2) even 'proliferative' T cells may fail to respond to certain target cells carrying the specific antigen, such as a murine transfectant, in the absence of exogenous IL-2.