Incidence of monoclonal gammopathies in blood donors]

A routine screening of monoclonal gammopathies (M.G.) was performed in the serum from 36, 015 blood donors by cellulose acetate electrophoresis. The incidence of M.G. was estimated to 0.14 per cent. About 86 per cent of cases can be classified as asymptomatic M.G. and 14 per cent as malignant M.G. (myeloma or Waldenstr?m macroglobulinemia). In asymptomatic forms, heavy chain classes are only IgG or IgM with a large predominance of IgG (86,4%). It is suggested that donors in whom M.G. have been detected should not be allowed to give blood. A yearly clinical, hematological and an immunoglobulin check-up is recommended to these patients in order to defect the first sign of a malignant process.     

Persistence of antibodies of the IgG class against cytomegaloviruses in blood donors

High titre plasmas gained from blood donors are the initial material used for producing human immunoglobulin containing cytomegalovirus antibodies (CMV-HIG). For this purpose the sera gained from 467 permanent donors at the District Institute for Blood and Transfusion Service in Berlin were investigated on their CMV antibody content of IgG class by means of an indirect immunofluorescence test (IFT). The infection rate of blood donors amounted to 62% (291/467). CMV-IgG titre greater than or equal to 1:40 was determined in 88 sera (18.8%) and greater than or equal to 1:160 in 14 sera (3%). Two CMV-HIG laboratory samples (charges 3113 and 3117) were produced from these plasmas. Particularly immunoglobulin fraction of charge 3117 (No. 3117 N II) revealed excellent antibody titres (IFT 1:640 [CMV-IgG] or 1:40 [CMV-IgM] respectively, neutralisation test 1:32). Checks made with the donors' CMV-IgG titres after repeated application of plasmapheresis resulted in maximal titres changes of two dilution stages in a period of 15 months. Thus, in producing CMV-HIG a sure, tested pool of donors can be resorted to.     

Blood coagulation and fibrinolysis in blood donors after plasmapheresis]

Authors were interested in blood coagulation proteins and fibrinolysis in blood donors following several plasmaphereses. This interest was related to the occurrence of thrombo-embolic and hemorrhagic complications in these subjects. Blood morphology, serum protein, blood coagulation and fibrinolysis have been examined in 40 healthy blood donors, aged between 19 and 46 years, who gave blood plasma by plasmapheresis technique for 1-59 times. Results did not show any significant changes in blood morphology and serum protein levels prior to and after consecutive plasmaphereses. No significant decrease in blood coagulation proteins and fibrinolysis has been noted. However, a significant increase in factors VIII and IX activities was noted in several blood donors, who underwent the largest number of plasmaphereses. It may predispose these donors to thrombo-embolic complications.     

Detection of IgA defects in blood donors using an enzyme immunoassay

An enzyme immunoassay is presented for screening blood donors for IgA-defects using horseradish peroxidase conjugated IgA. Fife of about 4,700 screened donors was found to be IgA-deficient. With another EIA using horseradish peroxidase conjugated monoclonal anti-IgA and IgA coated microplates the IgA-concentration in serum of these selected donors was determined.     

Iron stores in female blood donors evaluated by serum ferritin

Iron stores were evaluated by serum ferritin determinations in 948 menstruating and 141 non-menstruating female blood donors. Blood donation was associated with a decrease in ferritin. First-time donors (n = 163) had a geometric mean ferritin of 24 micrograms/l and multiple-time donors a value of 19 micrograms/l (p less than 0.01). In the donating population 31.5% had ferritin values less than 15 micrograms/l (i.e. depleted iron stores). Menstruating donors had lower mean serum ferritin than non-menstruating donors (p less than 0.001), and a higher frequency of ferritin values less than 15 micrograms/l (p less than 0.05). There was no relationship between ferritin levels and the number of pregnancies. The frequency of donations was more predictive of ferritin levels than the number of donations. Mean ferritin displayed a moderate fall up to the 2nd donation, and was hereafter relatively constant, whereas an increase in donation frequency was accompanied by a significant decrease in ferritin. Female donors, especially when phlebotomised greater than or equal to 3 times per year, should have their iron status checked at appropriate intervals by measurement of serum ferritin and should be advised regular iron supplementation.     

Identification of HCV genotypes in HCV infected blood donors

HCV infection is a leading cause of chronic liver disease, including cirrhosis of the liver. There are at least six major genotypes and more than 50 subtypes of HCV. The prevalence and distribution of HCV genotypes depend on geographical location. The aim of this study was to identify and compare the HCV genotypes in HCV infected blood donors and patients. In this cross-sectional study, 167 serum samples from 103 blood donors and 64 patients with hepatitis C were investigated for HCV genotypes. HCV genotyping was carried out using type-specific primers from the core region of the viral genome. The highest frequency was for genotype 1a, with 53 and 34 (51.5% versus 53.1%) of subjects in blood donors and patients respectively. Genotype 3a and 1b were the other frequent genotypes with 4 and 16 (3.9% versus 25%) and 39 and 10 (37.9% versus 15.6%) subjects, respectively. There was not any statistical significant association between the place of infection of the patients and genotype. The results of this study indicate that the distribution of genotypes in the two populations was similar. The dominant HCV genotypes between blood donors and patients were 1a, 3a and 1b respectively.     

The course of serum ferritin in blood donors

In the course of 18 months there occurred a decrease in the serum ferritin concentration from 58 +/- 2 micrograms/l to 32 +/- 1 micrograms/l in male donors after 5-6 donations of 400 ml of blood each. Female permanent donors showed a constantly lowered content of an average of 15 +/- 1 micrograms/l. Female first donors attained the serum ferritin level of permanent female donors with the fourth donation, whereas it was not until the fifth donation that male first donors declined to the level of permanent donors. This decrease of serum ferritin content in blood donors points to a depletion of iron stores. This process should be counteracted by exerting an increased influence on nutritional habits supported by oral iron substitution and diminishing the frequency of donation, particularly for female blood donors.     

The seroprevalence of SARS-CoV-2 IgG antibodies among asymptomatic blood donors in Saudi Arabia

BackgroundIn late 2019, cases of severe pneumonia with unidentified etiology began to emerge in Wuhan, China, before progressively spreading first nationally and then globally.The current study sought to investigate the seroprevalence of immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among blood donors in Al-Madinah, Saudi Arabia. To our knowledge, this is the first study in Saudi Arabia to screen blood donors who were not known to be previously infected with SARS-CoV-2.MethodsThis study was a cross-sectional study to assess individuals who donated blood to the central blood bank in Al-Madinah between mid-May and mid-July 2020. An enzyme-linked immunosorbent assay (ELISA) was designed and established to detect antibodies directed against the SARS-CoV-2 spike protein in serum samples. A total of 1,212 healthy blood donors participated in this study. The donors were males and met the requirements for blood donation during the COVID-19 pandemic period in Saudi Arabia.ResultsThe SARS-CoV-2 seroprevalence among blood donors in Al-Madinah was 19.31% (n = 234/1212; 95% confidence interval: 17.12%–21.64%). No statistically significant difference was identified in seropositivity according to age. However, significant differences (p < 0.001) were identified according to ABO blood groups, with those with type A blood presenting the highest rate of seropositivity (29.18%) compared with the other blood groups (12.65% for type B, 16.36% for type AB, and 15.11% for type O).ConclusionA high prevalence of SARS-CoV-2 antibodies was detected among blood donors in Al-Madinah, which indicated a high level of exposure to the virus within the population. This further suggested that as high as one-fifth of the population may have acquired innate immunity against the virus.     

Screening of carriers of antitetanus antibodies in blood donors

A screening of antitetanic antibody (AcAT) carriers has been carried out in 4770 blood donors. The percentage of "positive" subjects (with a rate of AcAT greater than or equal to 5 U.I./ml according to Laurell's method) is relatively high: 6,62%. The aim of a statistical study is to find out the distribution of AcAT carriers according to different factors: the chi 2 test allows us to conclude that the relation between the frequency of "positive" AcAT carriers and the blood groups is not significant but there is a significant connection between the frequency of "positive" AcAT carriers, sex and age. Our conclusions agree with those of authors having performed the study after vaccination. Our study has a double advantage: it allows us to know the vaccination state of the blood donors before any vaccination and allows the collecting of "positive" serum samples without having to wait for the vaccination.     

Screening for Chagas disease by immunoenzymology: comparison of ELISA with immunofluorescence and indirect hemagglutination in 976 blood donors

The efficiency of an immunoenzymatic technique (ELISA) for the systematic research of Chagas' disease in blood donors was compared with one of 2 well-known methods, indirect haemagglutination (IHA) and indirect fluoro immuno assay (IFA). For the ELISA technique two different antigenic extracts from epimastigote culture forms of T. cruzi, were used for sensitizing the polystyrene plates: a crude extract (Ag R) and a delipidized one (Ag B). Firstly the authors tested these 3 techniques in 5 control groups: sera from Chagas' disease, negative control sera, sera from visceral leishmaniasis, african trypanosomiasis and finally monoclonal gammapathies, the high levels of blood proteins being a possible cause of false positives. Secondly the screening of Chagas' disease was performed in the same way in 976 blood donors from Recife, Brazil. In the case of the Ag-R extract used in the ELISA technique a high cross-reactivity was found with visceral leishmaniasis sera, along a risk of false positives with gammapathic ones. The sensitivity of this technique was found to be high (3,3 +/- 1 p. cent of positive blood donors) and a very good correlation was found with the reference techniques, IFA and IHA, the sensitivity of which is lower (2,3 +/- 1 and 1,7 +/- p. cent). The use of a delipidized antigenic extract (Ag B) for the ELISA technique is not suitable, in spite of an apparent higher specificity: indeed, the positives rate is high (11,5 +/- 0,2 p. cent), but the correlation is very weak or non existent in the case of IHA or IFA. In conclusion, the ELISA technique using a crude extract of T. cruzi appears to be a very convenient method for screening blood donors with Chagas' disease, the lack of specificity due to leishmaniasis or monoclonal blood proteins not posing any real problem to blood banking.     

Serum ferritin estimation in blood donors subject to apheresis on IBM 2997 cell separator

The serum ferritin concentration was tested in blood donors selected for apheresis on IBM Cell Separator. Of 41 donors, 28 were males and 13 females. All donors exhibited normal hemoglobin and RBC. The mean value of serum ferritin was 90.93 ng/ml in males and 48.38 ng/ml in females. In males--often with repeated blood donations--a low value of serum ferritin suggesting reduced Fe stores in organism was found in one individual only. In contrast, reduced serum ferritin levels were observed in 4 females who, before apheresis, regularly donated blood or had several pregnancies in their anamnesis. The obtained results point to prelatent or latent sideropenia. Serum ferritin concentration was measured in 18 donors selected for apheresis. The examination of ferritin was performed prior to, immediately after, and one week post separation. No significant changes in serum ferritin concentrations due to the separation procedure were observed. Preventive tests of serum ferritin in multiple blood donations and in women with previous pregnancies are recommended.     

Human cytotoxic T cells stimulated by antigen on dendritic cells recognize the N, SH, F, M, 22K, and 1b proteins of respiratory syncytial virus.

We examined the human cytotoxic T-cell repertoire of nine adults to 9 of the 10 proteins of respiratory syncytial (RS) virus. Peripheral blood mononuclear cells from normal adults were stimulated with RS virus in vitro. The resulting polyclonal cultures were tested for lysis of B-lymphoblastoid cell lines infected with recombinant vaccinia viruses expressing each of nine individual RS virus proteins. The use of peripheral blood dendritic cells to present antigen gave more easily reproducible results over a shorter culture period than conventional methods. The six RS virus proteins most strongly recognized were the nucleoprotein N (nine of nine donors with greater than 10% above background lysis; P = 0.0004), the surface proteins SH (six of nine donors; P = 0.002) and F (five of nine donors; P = 0.008), the matrix proteins M (five of nine donors; P = 0.004) and 22K (three of nine donors; P = 0.01) and the nonstructural protein 1b (six of nine donors; P = 0.004). There was no significant recognition of the major surface glycoprotein G (two of nine donors), the internal phosphoprotein P (one of nine donors), or the nonstructural protein 1c (one of nine donors). Recognition was major histocompatibility complex class I restricted, but no association between major histocompatibility complex phenotype and protein specificity of T cells was seen. Recognition of F and 22K appeared to be associated with recent infection indicated by increased levels of anti-RS virus immunoglobulin G antibody in serum measured by enzyme-linked immunosorbent assay. Since cytotoxic T-cell recognition of RS virus proteins has been demonstrated to be important in the clearance of virus from infected hosts, the N, M, SH, 1b, F, and 22K proteins should be considered potential vaccine components.     

The high prevalence of Torque teno virus DNA in blood donors and haemodialysis patients in southern Brazil

This study investigates the frequency of Torque teno virus (TTV) infection in 150 blood donors and 77 patients requiring haemodialysis in southern Brazil. Plasma samples were screened for TTV DNA using polymerase chain reaction (PCR). The prevalences of TTV among blood donors and patients requiring haemodialysis were 73.3% and 68.8%, respectively. The presence of TTV was correlated with age in the blood donors (p = 0.024). In haemodialysis patients, no association was found between TTV infection and the demographic parameters (age, sex and education), the duration of haemodialysis or a history of blood transfusion. This study is the first to evaluate the prevalence of TTV infection in Brazilian patients requiring haemodialysis.     

Detection of lipid abnormalities in blood donors]

The high incidence of cardio- or cerebro-vascular diseases is positively correlated with hyperlipoproteinemia. A large-scale screening of blood donor's populations could be used for the prevention of the atherogenic disease. Therefore lipoproteins electrophoresis on cellogel was compared with serum levels of triglycerides, cholesterol and lipids in 1184 blood donors (792 men, 392 women). The electrophoretic pattern was found abnormal in 32 cases (25 men, 7 women). It was a type IIb hyperlipoproteinemia, according to the classification of the World Health Organization. In these 32 subjects, serum triglycerides, cholesterol and lipids concentrations were significantly higher (p less than 0,001) than in 41 other donors with a normal electrophoretic pattern. A good positive correlation was found between high blood pressure or obesity or blood group O and abnormal electrophoretic pattern. Lipoproteins electrophoresis on cellogel appears to be a suitable test (easy, fast and economical) in large-scale screening for dyslipidemia in subjects over 40, or at least in cases of mild hypertension or obesity.     

Serum proteins and paraproteins in women with silicone implants and connective tissue disease: a case-control study

Prior studies have suggested abnormalities of serum proteins, including paraproteins, in women with silicone implants but did not control for the presence of connective-tissue disease (CTD). This retrospective case-control study, performed in tertiary-care academic centers, assessed possible alterations of serum proteins, including paraproteins, in such a population. Seventy-four women with silicone implants who subsequently developed CTD, and 74 age-matched and CTD-matched women without silicone implants, were assessed in the primary study; other groups were used for additional comparisons. Routine serum protein determinations and high-sensitivity protein electrophoresis and immunofixation electrophoresis were performed for detection of paraproteins. Women with silicone implants, either with or without CTD, had significantly lower serum total protein and alpha1-globulin, alpha2-globulin, beta-globulin, gamma-globulin, and IgG levels compared with those without silicone implants. There was no significant difference, however, in the frequency of paraproteinemia between women with silicone implants and CTD (9.5%) and age-matched and CTD-matched women without silicone implants (5.4%) (odds ratio, 1.82; 95% confidence interval, 0.51-6.45). Paraprotein isotypes were similar in the two groups, and the clinical characteristics of the 13 women with paraproteinemia were comparable with an independent population of 10 women with silicone breast implants, CTD, and previously diagnosed monoclonal gammopathies. In summary, this first comprehensive study of serum proteins in women with silicone implants and CTD found no substantially increased risk of monoclonal gammopathy. Women with silicone implants, however, had unexpectedly low serum globulin and immunoglobulin levels, with or without the subsequent development of CTD. The causes and clinical implications of these findings require further investigation.     

Isoamylases in blood donors

Summary Sera of 1,000 blood donors were tested for various combinations of salivary and pancreatic amylase isoenzymes and the frequency of their occurrence was determined in the series mentioned. Five combinations of isoamylases were found. A combination of 1 salivary and 1 pancreatic amylase was found most frequently (89.5%), the frequency of the other four combinations was relatively low (0.2–5.1%).Hereditary character of amylase isoenzymes was confirmed in a series of 36 families.     

Studies of cultured human T lymphocytes. II. Initiation of paired T- and B-cell lines from healthy donors

We report the sustained cultivation of both B- and T-lymphoblastoid cell lines from randomly selected healthy donors, and the results of studies defining the frequency with which these cell lines can be established. B-cell lines were initiated using the Epstein-Barr virus. Of 52 attempts, 40 B-cell lines (77% success) were obtained from 24 different donors. T-cell lines were started and propagated in long-term (greater than 100 days) cultures using the T-cell growth factor interleukin-2 (IL-2). Of 55 attempts, 54 (98%) were successful in initiating IL-2-dependent T-cell lines, and these were derived from 28 healthy adults. Likewise, of 45 attempts, 32 (71%) were successful in producing paired lines in which both the B-cell line and T-cell line were cultivated from a single blood collection (N = 22 donors). Phenotypic profiles of these lines were defined using multiple marker assays, including rosette formation, surface immunoglobulins, cytochemistry, karyotype, as well as xenoantisera and monoclonal antibodies defining different membrane antigens. This work demonstrates the feasibility of propagating paired human B and T lymphoblastoid lines suitable for many comparative immunobiological studies.     

The pharyngeal beta-hemolytic streptococcal carrier state among blood donors

459 blood donors aged 18-50 years were examined in 1987-1988 in Moscow. Among them, carrier state with respect to beta-hemolytic streptococci was detected in 107 donors (23.3%). The number of carriers gradually decreased with the increase of age of the examined donors. Group C streptococci occurred least of all (6.9%). Group A beta-hemolytic streptococci were isolated in 16.7% of the carriers. The isolation rate of streptococci from blood achieved its maximum in autumn and winter months and did not depend on preceding diseases, unhealthy working conditions, the rhesus factor and, with the exception of group A streptococci, the blood group. Among tonsillectomized donors carrier state with respect to beta-hemolytic streptococci occurred 2.2 times less frequently than among donors who had not undergone tonsillectomy. Carrier state with respect to beta-hemolytic streptococci was accompanied by higher levels of salivary sIgA antibodies to polysaccharide A, serum antibodies to polysaccharide A and circulating polysaccharide A. All beta-hemolytic streptococci were sensitive to erythromycin. All groups of streptococci showed the highest percentage of cultures resistant to gentamicin and tetracycline. In 100% of cases group A streptococci were sensitive to benzylpenicillin, methicillin, ampicillin, erythromycin and lincomycin.     

Molecular analysis of homeostatic iron regulator,transmembrane protease serine-6, and BTB domain-containing protein-9 variants and iron parameters in blood donors

Genetic variants associated with iron homeostasis have been identified, but their association with iron-related indices and variables among different ethnic populations remains controversial. We aimed to explore the genotype frequency and allelic distribution of three iron-metabolism related variants in homeostatic iron regulator gene (HFE; rs1800562 G/A), transmembrane protease, Serine-6 gene (TMPRSS6; rs855791 A/G), and BTB domain-containing protein-9 gene (BTBD9; rs9357271 C/T) among a sample of the Middle Eastern blood donors and to detect the association of these variants on blood indices, and serum hepcidin/ferritin levels. Real-Time TaqMan genotyping assay for the specified variants was applied for 197 unrelated blood donors. Complete blood picture and serum hepcidin/ferritin levels were assessed. All participants were carriers of rs1800562*G/G genotype for HFE. The frequency of A/A and A/G genotypes of TMPRSS6 rs855791 variant was 55% and 45%, and for C/C, C/T, and T/T of BTBD9 rs9357271, were 15%, 43%, and 42%, respectively. Minor allele frequencies of rs855791*G and rs9357271*C were 0.23 and 0.37. The GGC genotype combination (for HFE/TMPRSS6/BTBD9, respectively) was more frequent in male participants. Higher serum hepcidin and hepcidin/ferritin ratio were observed in TMPRSS6 (A/G) carriers. While subjects with BTBD9 C/T and TT genotypes had lower serum ferritin values and higher levels of hepcidin and hepcidin/ferritin ratio compared with C/C genotype. No significant associations were found with any other blood parameters.In conclusion, TMPRSS6 rs855791 (A/G) and BTBD9 rs9357271 (C/T) variants were prevalent in the present blood donor population and may influence the serum hepcidin and/or ferritin levels.