Serum Samples Of Blood Donors Research Articles

IL-18 discriminates highly frequent hepatitis E virus positive from negative blood donors in Mexico

Introduction and ObjectivesHepatitis E virus (HEV) is not routinely screened in blood banks in low- and middle-income countries, and no specific biomarkers of exposure to this virus have yet been identified. We aimed to identify HEV seropositivity and detect virus RNA among blood donors from Mexico to further correlate risk factors related to infection and levels of interleukin-18 (IL-18) and interferon-gamma (IFN-γ) as potential biomarkers. Materials and MethodsThis cross-sectional, single-center study included 691 serum samples of blood donors obtained in 2019. Anti-HEV IgG and IgM antibodies were detected in sera and the viral genome was screened in pooled samples. A statistical comparison of risk factors for infection, demographic and clinical features was performed; IL-18 and IFN- γ values were tested in sera. ResultsOf all the individuals, 9.4% were positive for anti-HEV antibodies and viral RNA detection was confirmed in one of the pools positive for anti-HEV. From the analysis of risk factors, age and having pets were statistically significant for anti-HEV antibody detection. Seropositive samples showed significantly higher IL-18 concentrations relative to samples from seronegative donors. Interestingly, IL-18 values were similar when HEV seropositive samples were compared to samples from clinically acute previously confirmed HEV patients. ConclusionsOur findings highlight the need to follow up on HEV in blood banks in Mexico and underscore that IL-18 could represent a biomarker of HEV exposure.

The changing profile of SARS-CoV-2 serology in Irish blood donors

BackgroundThe present study aimed to investigate the progression of the SARS-CoV-2 pandemic in Ireland over the first three waves of infection. MethodA selection of blood donor serum samples collected between February 2020 and December 2021 were analysed by various commercially available serological assays for antibodies to SARS-CoV-2 (n = 15,066). ResultsAn increase in seropositivity was observed between wave 1 (February to September 2020) and wave 2 (November and December 2020) of 2.20% to 3.55%. A large increase in estimated seroprevalence to 11.89% was observed in samples collected in February and March 2021 (wave 3 of infection).The rate of seropositivity varied by age group, with the highest rate observed in the youngest donors (18–29 years) peaking at 18.79% in wave 3. The results of spike antibody (anti-S) testing indicated that 44/1009 (4.36%) of seroreactive donors in wave 3 had a serological profile consistent with vaccination. By November 2021, we detected an overall seropositivity of 97.04%. ConclusionsThe present study provides a comprehensive estimation of the level of circulating SARS-CoV-2 antibodies in Irish blood donors, enabling differentiation between vaccination and natural infection, as well as real-time monitoring of the progression of the COVID-19 pandemic in Ireland. Seroepidemiology has a role in determining reliable estimates of transmission, infection fatality rates and vaccine uptake. The continued screening of blood donors for this purpose has the potential to generate important data to assist with the management of future waves of SARS-CoV-2.

SERUM ANTIBODIES AGAINST GroEL AS AN ADDITIONAL RISK BIOMARKER OF BIOCHEMICAL RECURRENCE AFTER RADICAL PROSTATECTOMY.

Thelevel of heat shock protein 60 (Hsp60) is elevated in tumor cells compared with normal prostate epithelium. Hsp60is involved in tumor growth, invasion, and metastasis and is considered as a biomarker for cancer diagnosis and prognosis. To study thelevel of antibodies against prokaryotic homolog of human Hsp60 (GroEL) in prostate cancer (PCa) patients as an additional risk marker for theprediction of biochemical recurrence after radical prostatectomy (RP). A total of 55patients with localized and locally advanced PCa, who had undergone RP between July 2013and May 2014were enrolled. Level of antibodies to GroEL and human Hsp60was determined by enzyme-linked immunosorbent assay before surgery. Serum samples of blood donors with low reactivity to GroEL and human Hsp60were used as controls. Therelationship between IgG antibodies against bacterial Hsp60and human Hsp60and clinicopathological features were analyzed. Thebiochemical recurrence (BCR) free survival rate was estimated by theKaplan - Meier method. Theunivariate and multivariate Cox regression models were used to evaluate therisk factors of BCR-free survival rate. There were significant differences in anti-GroEL IgG levels between control and PCa patients while no significant differences in anti-human Hsp60IgG levels between control and PCa patients were detected. During thefollow-up period, 40/55 (72.7%) patients developed BCR. Thetime from surgery to BCR was from 18to 72months. Elevated IgG antibodies against bacterial Hsp60in patients who had undergone RP were associated with early occurrence of biochemical relapse and lower 5-year BCR-free survival rate respectively (p < 0.001). Themultivariate analysis indicated that IgG to GroEL (hazard ratio = 2.465; 95% confidence interval: 1.311-4.634, p < 0.05) could be independent prognostic factor in thepatients who had developed BCR. Elevated levels of IgG antibodies against GroEL before surgery can predict early occurrence of BCR after RP and can serve as an additional independent risk biomarker of a BCR after RP.

Comparing RT-qPCR and Hepatitis C Virus Antigen Detection Assay for Detecting Active Infection in Blood Donors in Fars Province, Iran

Background: Immunoassay is still used to detect hepatitis C virus (HCV) antibodies in donated blood in many developing countries. However, an immunoblotting confirmation test is needed to confirm positive results. Objectives: We compared the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of nucleic acid testing and HCV core antigen (HCVcAg) detection in the serum samples of blood donors with HCV antibodies to determine active infection. Methods: Overall, 90 serum samples from blood donors referred to Fars Blood Transfusion Organization, Iran during March 2017-March 2019 and initially tested for HCV antibodies were included in the study. Enzyme immunoassays were used to detect the HCV antigen and anti-HCV antibody. A commercial reverse transcription-polymerase chain reaction (RT-PCR) kit was used to quantify HCV RNA. The HCV genotypes were also determined by DNA sequencing. In order to compare the HCVcAg detection method with the RT-qPCR reference method, sensitivity, specificity, performance, PPV, and NPV were calculated. Results: Out of 90 serum samples, 73 were positive for anti-HCV antibody, and 17 sera were negative. The HCV RNA was detected in 60 (82%) of anti-HCV antibody-positive samples, whereas the HCVcAg test detected HCV antigen in 54 (74%) of the samples, indicating a significant correlation between the two assays (r = 0.86). The overall sensitivity and specificity for HCVcAg detection method were 93.85% [95% confidence interval (CI): 84.99 - 98.3%] and 100% (95% CI: 94.64 - 100%), respectively. Based on the statistical analysis, the accuracy of the antigen detection test was 94.83% (95% CI: 87.26 - 98.58%). Moreover, the agreement between HCV RNA detection using RT-qPCR and HCVcAg detection was 97.78% (kappa value: 0.94). Conclusions: The sensitivity and specificity of HCVcAg detection in blood donors were ideal compared to the RT-qPCR reference method. However, the method should be tested on more HCV antibody-positive and -negative samples. Furthermore, our study revealed a significant association between the number of RT-qPCR-positive cases and the cases diagnosed by the HCVcAg detection method for screening and detecting active HCV infection in blood donors.

Updated Seroprevalence of Hepatitis B Surface Antigen and Anti-Hepatitis Core Antibody Among Blood Donors in Yemen.

PurposeHepatitis B virus (HBV) is one of the most common infectious pathogens worldwide. Various studies found a prevalence of HBV infection among blood donors ranging from 2% to 18%. Hence, this study aimed to provide an updated prevalence of HBsAg and anti-HBcAb among blood donors.Patients and MethodsThis was a cross-sectional study to investigate the donation records of blood donors in Sana’a, Yemen, over one year (January to December 2019). Eligible blood donors were included in the study. The serum samples of blood donors were tested for HBsAg and anti-HBcAb (IgG & IgM) using the electrochemiluminescence (ECL) and enzyme immunoassay (EIA) techniques.ResultsA total of 16,367 blood donors were recruited in this study, of whom 14,300 (87.4%) donated only once during this study (single, non-duplicated blood donors), while 2067 (12.6%) were repeated or duplicated. The overall prevalence of HBsAg and anti-HBcAb was 2.4% and 10.8%, respectively. Among single non-duplicated blood donors, HBsAg and Anti-HBcAb were 2.3% and 10.6% and 3.0% and 12.5% for repeated blood donors, respectively. There were statistically significant differences between HBsAg and Anti-HBcAb in terms of donor type and testing techniques.ConclusionThe seroprevalence of HBsAg and anti-HBcAb among the blood donors was 2.0% and 10.3%, respectively. The ECL technique is more sensitive, has a lower error rate, and shows an advantage over the manual EIA technique. Duplicated blood donors influence the accuracy of the seroprevalence of HBsAg and anti-HBcAb.

Estimation of the hepatitis E assay-dependent seroprevalence among Croatian blood donors.

Seroprevalence of hepatitis E virus (HEV) in blood donors presenting to the Croatian Institute of Transfusion Medicine was assessed with 4 available tests (3 ELISA tests and 1 immunoblot (IB) test). In October and November 2014, a total of 1,036 serum samples of blood donors were collected for the study. Samples were primarily tested for total HEV antibodies by Dia.Pro HEV Ab test (a). All reactive samples were tested by ELISA tests: Dia.Pro HEV IgG (b) and IgM (c), Mikrogen recomWell HEV IgG_old (d) and IgM_old (e), recomWell HEV IgG_new (f) and IgM_new (g), and IB Mikrogen recomLine HEV IgG (h) and IgM (i). HEV IgM reactive samples also positive by the IB were further tested for HEV RNA. There were 21.5% of samples reactive for total HEV antibodies (a). Seroprevalence of HEV IgG according to the b, d, f and h tests was 20.2%, 9.6%, 18.1% and 17.8%, respectively. Seroprevalence of HEV IgM according to the c, e, g and i tests was 4.4%, 1.5%, 2.0% and 1.7%, respectively. Out of 46 HEV IgM (Dia.Pro HEV IgM) positive samples, 18 (39.1%) were also positive by IB. HEV RNA was not detected in any of those samples. There was a significant association between age and HEV seroprevalence (P<0.001). Different HEV antibody detection assays showed a high HEV IgG seroprevalence in Croatian blood donors. Among HEV IgG and HEV IgM positive samples HEV RNA was not detected.

Baseline titres of O, H and AH agglutinins to Salmonella Typhi and Paratyphi A in blood donors in Sri Lanka.

Background: Sri Lanka is considered as an endemic country for enteric fever. Due to difficulties in performing blood cultures, the Widal test is still commonly carried out for the diagnosis of enteric fever. However, there are no published data on current baseline Widal titres in the country. This study was carried out to determine the baseline titres of O, H and AH agglutinins among the Sri Lankan population. Method: Five hundred and one (501) serum samples of blood donors from 31 blood banks in Sri Lanka were collected during 2012 and 2013 and were screened for Salmonella O, H and AH agglutinins using the Widal tube test. A titre of 20 and above was considered positive. Age and gender of the study participants were recorded. Results: Of the 501 sera tested, 58% were positive for at least one of the O, H and AH agglutinins. Salmonella O, H and AH agglutinins were positive in 46.1%, 26.5% and 8.4% of the study population respectively. Of the study population, 97.5% had O, H and AH agglutinin titres less than or equal to 80, 160 and 80 respectively. A significantly higher percentage of females (H-36.7%, p=0.019; AH-15.3%, p=0.15) were positive for H and AH agglutinins than males (H-24.9%; AH-7.4%). The baseline titre of AH agglutinins was higher in females (160) than males or the total population (80). Highest test positivity (40%) was seen among the 31-40 year age group. A significant number of donors below 20 were negative for Salmonella O agglutinins (p=0.024). Conclusion: We recommend baseline titres of 80, 160 and 80 for Salmonella O, H and AH agglutinins respectively to be used in Sri Lankan settings. As there is a variation in baseline titre with age and gender it is necessary to consider both when interpreting Widal test results.

Treponema pallidum hemagglutination assay seroreactivity among healthy Indian donors and its association with other transfusion transmitted diseases.

Background:The aim of the present study was to determine the prevalence of syphilis infection by Treponema pallidum hemagglutination assay (TPHA) among blood donors in Delhi and to study their correlation with other markers of transfusion transmitted infections such as hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B surface antigen (HBsAg) so as to establish the utility of TPHA over and above venereal diseases research laboratory test (VDRL), not only as a marker for testing T. pallidum infection, but also as a marker of high risk behavior.Materials and Methods:This prospective study was carried out in the Regional Blood Transfusion Centre, Lady Hardinge Medical College and associated Sucheta Kriplani Hospital, New Delhi for a period of 2 years. Donated blood was screened for TPHA seroreactivity along with screening for anti HIV I and II, anti-HCV, HBsAg by third generation enzyme-linked immunosorbent assay test. A total of 8082 serum samples of blood donors were collected from healthy blood donors in our blood bank. They were classified into two groups- test group and control group based on TPHA positivity. The co-occurrence of HBsAg, HIV and HCV infection were determined in TPHA positive blood donors (test group) in comparison with TPHA negative blood donors (control group).Results:We found the TPHA seroreactivity to be 4.4% in Delhi's blood donors. Nearly 8.2% (663/8082) of the donated blood had serological evidence of infection by at least one pathogen (syphilis/HIV/hepatitis B virus/HCV) and 6.63% (44/663) donors with positive serology had multiple infections (two or more). Quadruple infection was seen in one donor, triple infection was seen in three donors and double infection was seen in 40 donors. Prevalence of HIV seroreactivity was found to be statistically significant and HCV seroreactivity statistically insignificant in TPHA positive group in comparison to TPHA negative group.Discussion:In our study, the TPHA seropositivity correlated with higher HIV and HCV seropositivity and the same correlation has been observed by several other studies also. In view of these observations, we propose that testing for syphilis by more sensitive and specific treponemal markers like TPHA rather than VDRL, rapid plasma reagin tests; as TPHA also has the added advantage of picking up all the high risk donors, whereas, VDRL picks up only currently infected donors. Moreover, TPHA should be continued as a marker of high risk behavior especially in high prevalence areas like India where we don’t have universal access to markers like nucleic acid amplification technique.

Cross-reactivity between cockroach and ladybug using the radioallergosorbent test

Home infestations from Harmonia axyridis (ladybug) occur throughout the United States. IgE-mediated sensitization with allergic disease has been reported. The prevalence of ladybug sensitization has been studied by questionnaire and allergy testing in patients diagnosed as having allergic disease. Cross-reactivity with cockroach exists. To determine the prevalence of ladybug specific IgE in the general population by specific IgE immunoassay and to examine cross-reactivity to cockroach. An experimental solid phase for use in immunoassay was prepared using a ladybug extract, and performance characteristics were determined. Serum samples from 100 adult blood bank donors were tested using the ladybug specific IgE immunoassay. Known ladybug IgE-positive serum samples obtained from symptomatic patients were used to study crossreactivity with German cockroach by specific IgE immunoassay inhibition. The mean background response of the assay solid phase was 51 fluorescent units with an analytical cutoff of 59 fluorescent units. It was estimated that a response of 88 fluorescent units corresponds to a specific IgE concentration of 0.1 kUa/L. The extinction dilution curve was linear to 0.1 kUa/L. The assay cutoff was set at 0.1 kUa/L. Of the 100 blood donor serum samples, 10 were positive for ladybug specific IgE. Inhibition assays revealed partial cross-reactivity with German cockroach. Although an immunoassay solid phase prepared with ladybug whole body extract will identify persons in a general population sensitized to epitopes found in the extract, clinicians performing allergy testing using whole body ladybug extract should be aware that a positive result may or may not indicate that exposure to actual ladybug allergens is causing sensitization.

Evaluation of serological tests for the diagnosis of rickettsiosis in Denmark

Two commercially available immunofluorescence assays (IFA) were compared using historical sera evaluated for rickettsial antibodies by the Weil-Felix test. An IFA test produced by Focus Diagnostics prepared with Rickettsia rickettsii and R. typhi antigens was compared with a custom made kit from Fuller Laboratories with R. rickettsii, R. typhi, R. conorii and R. helvetica as antigens. The serum panel used for the comparison included Weil-Felix-positive and -negative samples. Cross-reactions were analyzed using serum samples from patients with clinical symptoms similar to those of rickettsiosis. When analyzing the data using the manufacturers' cut-off values, 41% of samples from presumably healthy blood donors were found positive for spotted fever group Rickettsia antibodies. This does not correlate to the general picture of rickettsiosis in Denmark. Furthermore, sera with Coxiella burnetii antibodies were found to be cross-reacting in both tests. When applying cut-off values calculated on the 95% percentile on data from blood donor serum samples, there was no significant difference between the two kits. Moreover, when using the newly established cut-off, cross-reactions were eliminated.

Seroepidemiological aspects of human Strongyloides stercoralis infections in Chile

To determine the frequency of Strongyloides stercoralis antibodies by means of the enzyme linked immunosorbent assay (ELISA) in Chile, in 2001-2003, 675 blood samples of patients of two psychiatric hospitals and 172 of healthy individuals (doctors, nurses and paramedicals) of these institutions, and 1,200 serum samples of blood donors of Northern region (Arica and Antofagasta), Central region (Valparaiso and Santiago) and Southern region (La Union) were collected. ELISA showed positivity of 12.1% in psychiatric hospitalized patients, none (0%) in the health personnel and 0.25% in blood donors (p < 0.05). Only in blood donors of Arica (1%) and La Union (0.5%) the ELISA test was positive suggesting that strongyloidiasis is focalized in determinate zones of the country. In Chile, human infections by S. stercoralis are endemic with very low frequency in apparently healthy individuals and high prevalence in risk groups such as the mentally ill hospitalized patients.

Prevalence and phylogenetic characterisation of TT-virus in the blood donor population of Auckland, New Zealand.

TT-virus (TTV, patient initials: T.T.), a novel DNA virus, was first isolated in Japan in 1997 from serum of a patient with post-transfusion hepatitis of unknown aetiology. To date, the contribution of TTV to liver disease remains doubtful. The potential for transmission via blood and blood products makes it essential to establish the prevalence of TTV viraemia in the blood donor population. 413 blood donor serum samples were chosen randomly, the DNA was extracted and TTV-specific DNA amplified by nested polymerase chain reaction (PCR). TTV infection was present in 13 out of 413 (3.15%) blood donors in the Auckland region of New Zealand using a set of primers targeting open reading frame (ORF) 1. These 13 amplification products (264 bp) were sequenced and TTV genotypes determined. Alignment with published TTV sequences showed that seven (53.8%) of the thirteen positive serum samples belonged to genotype 1, five (38.5%) belonged to genotype 2 and one (7.7%) could not be classified as either genotype 1 or 2. One hundred twenty-seven blood donor serum samples were retested with a second set of primers targeting the 5' region of the TTV genome in a single round PCR. Forty-three samples were positive for TTV DNA with these primers resulting in a prevalence of 37%. The data demonstrate that TTV is present among New Zealand blood donors and support the need for further investigation into the natural history of TTV infection.

Hepatitis-Associated Antigen in Blood Donor Populations

Blood-donor serum samples from five medical centers, tested for hepatitis-associated antigen (HAA), showed widely varying incidence (0.06% to 1.47%). The incidence of HAA in the donor population correlated excellently with that of overt posttransfusion hepatitis. The sensitivity of the agar-gel immunodiffusion test was evaluated by study of the serum of 92 blood donors highly implicated in the transmission of hepatitis. Seventeen percent of these implicated donors were found to be HAA-positive, compared to 0.2% of 13,049 normal donors.