PubMed Health⌕ Search

Biomedical subjects

H Vrielink

Publications and source records attributed to H Vrielink.

At least 19 recordsLinked to original sources
PubMed2002

Prevalence of and risk factors for HIV infection in blood donors and various population subgroups in Ethiopia.

The aim was to determine the prevalence of HIV infection and risk factors for HIV infection in various population subgroups in Ethiopia. Serum panels from blood donors (n = 2610), from various population subgroups in Ethiopia were tested for anti-HIV-1/2 by ELISA. All ELISA repeatedly reactive samples were subjected for confirmation by immunoblot (IB) and anti-HIV-1 and anti-HIV-2 specific ELISAs. 155/2610 (5.9%) blood donors were HIV-1 infected. Of pregnant women, 84/797 (10.5%) were HIV-1 infected, and 1/797 (0.1%) was HIV-2 infected. 1/240 (0.4%) individuals from the rural population were HIV-1 infected. 198/480 (41.3%) female attendees, and 106/419 (25.3%) male attendees at sexual transmitted disease (STD) clinics were HIV-1 infected. One (0.2%) male, and 2 (0.4%) female STD patients were infected with both HIV-1 and HIV-2. It was concluded that the prevalence of HIV-1 infection varied from 0.4% among urban residents to 25.3-41.3% among STD attendees. There is a low prevalence of HIV-2 present in Ethiopian subjects. Risky sexual behaviour is significantly associated with HIV-infection in Ethiopia.

Adolescent↗
PubMed2001

Early detection of hepatitis B surface antigen and detection of HBsAg mutants: a comparison of five assays.

BACKGROUND AND OBJECTIVES: Assays for the detection of hepatitis B surface antigen (HBsAg) face two challenges: the emergence of sensitive techniques for detection of hepatitis B virus DNA and the existence of HBsAg mutant hepatitis B viruses. We studied the sensitivity of five modern assays for detection of HBsAg. MATERIALS AND METHODS: The sensitivity of two mini robot-based assays--IMx HBsAg V2 and Vidas HBsAg--and three enzyme-linked immunosorbent assays (ELISAs) with microtitre plate format--Hepanostika Uni-Form II v1.2, Monolisa Ag HBs Plus and HBsAg Test System 3--was compared testing 11 HBsAg seroconversion series, serial dilutions prepared from three HBsAg standards and nine HBsAg mutant samples. RESULTS AND CONCLUSION: Overall, the IMx HBsAg V2 assay showed the highest sensitivity. It outperformed the Vidas HBsAg in analytical sensitivity and in detection of HBsAg mutants. Among the microtitre plate ELISAs, the Monolisa Ag HBs Plus outperformed the HBsAg Test System 3 in detection of HBsAg mutants and it surpassed the Hepanostika Uni-Form II v1.2 in analytical sensitivity.

Diagnostic Equipment↗
PubMed2000

Variable leukocyte composition of red blood cell concentrates prepared in top-bottom systems: possible implications for pre-transplant blood transfusion.

BACKGROUND AND OBJECTIVES: The beneficial effect of blood transfusion on kidney graft survival requires the presence of leukocytes in the transfusate, but a minimal dose has not been defined, nor has the role of individual leukocyte subsets been investigated. In the Netherlands, a standard pre-transplant blood transfusion consists of a buffy coat (BC)-depleted red blood cell concentrate (RBCC) containing a maximum of 1.2x10(9) residual leukocytes per unit. However, leukocyte subset composition is not standardized. MATERIALS AND METHODS: Using FACS analysis, this study compared the residual leukocyte composition of RBCCs produced by Compomat((R)) and Optipress((R)), two currently used top-bottom systems. RESULTS: While the total leukocyte content of the RBCCs was equivalent in both press types (0.5x10(9)), the percentage of mononuclear cells (lymphocytes and monocytes) was significantly higher in the Compomat as compared with the Optipress system (p < 0. 0001), resulting in significantly higher numbers of transfused T cells, B cells, HLA-DR-positive cells, NK cells and stem cells. CONCLUSIONS: The leukocyte composition of a pre-transplant blood transfusion depends on the BC depletion method used; this might differentially affect the tolerizing or immunizing potential of a pre-transplant blood transfusion.

Blood Cell Count↗
PubMed1999

Comparison of four HTLV-I and HTLV-I + II ELISAs.

BACKGROUND: Various countries require blood donor screening using assays applying specific HTLV-I and HTLV-II antigens. We evaluated the sensitivity and specificity of 4 anti-HTLV-I + II ELISAs (Abbott, Murex, Organon Teknika and Ortho). METHODS: Panel A consisted of HTLV-I-positive individuals (n = 41), panel B of Mixed Titer Performance Panel 204 (Boston Biomedica Inc. panels C and D of dilution series from HTLV-I-positive (n= 30) and HTLV-II-positive (n =20) individuals and panel E of sera from first-time blood donors (n = 1,055). RESULTS: In HTLV-I- and -II-positive samples, a sensitivity of 100% could be observed in all 4 ELISAs. In diluted HTLV-I- and -II-positive samples, probit analysis revealed that the Murex assay had the highest analytical sensitivity, followed by the ELISAs from Ortho, Abbott and Organon Teknika. In specimens from first-time donors, a specificity of 100% was observed in ELISAs from Murex, Organon Teknika and Ortho, and of 99.7% in the assay from Abbott. CONCLUSION: The 4 anti-HTLV-I + II ELISAs studied were appropriate as screening tests.

Blood Donors↗
PubMed1999

Collection of heparinized plasma by plasmapheresis.

BACKGROUND AND OBJECTIVES: Heparinized plasma can be used for exchange transfusions in neonates and is usually collected by drawing whole blood using heparin as anticoagulant. The heparinized red blood cells and buffy coat cannot be used and are therefore discarded. To collect heparinized plasma more efficiently, a method was developed using an apheresis machine. MATERIALS AND METHODS: With an MCS3p apheresis machine (Haemonetics), plasma was collected from volunteer donors as anticoagulant, heparin in saline (30,000 IU/l) was added in a 1:9 ratio. The activated partial thromboplastin time (APTT) of the donors was measured before and immediately after the procedure, and various parameters were determined in the collected plasma. RESULTS: In 2 collection cycles, an average of 456+/-52 ml (mean +/- SD; n = 20) of heparinized plasma was collected, and 504+/-57 ml (n = 2; donors with a high hemoglobin level) when 3 cycles were performed. The leukocyte and platelet contamination in the plasma (n = 22) was 1.11+/-0.92x10(6) and 0. 05+/-0.22x10(9) per unit, respectively, which conformed to national specifications. Sodium levels were normal, but due to dilution of the plasma with heparin solution, potassium and calcium levels were about 20% lower than the serum levels in the donors. The donor APTT values were slightly longer after the procedure than before, but remained all within normal values. CONCLUSION: For the collection of heparinized plasma, apheresis has the advantage that (1) high-quality heparinized plasma can be harvested; (2) no blood components need to be discarded; (3) more plasma can be harvested with each donation, and (4) these procedures can be performed more often than whole blood donations.

Adult↗
PubMed1998

Transfusion-transmissible infections.

Infectious agents, including viruses, bacteria, and parasites, can be transmitted by human blood products. Of major importance are viruses such as human immunodeficiency virus types 1 and 2 (HIV-1/2), hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-cell lymphotropic virus types I and II (HTLV-I/II). Also, other viruses such as cytomegalovirus, Epstein-Barr virus, human parvovirus B19, and hepatitis A and G viruses can be transmitted by blood products. Various methods are used to prevent transmission of blood-borne agents to recipients, such as donor selection, testing donated blood for various infectious agents, and viral inactivation of plasma derivatives. With all these precautionary measures, the estimated risk for infection by screened blood components in Europe and the United States is approximately 1 in 50,000 to 1.6 million (for HBV, HCV, and HIV-1/2) transfused blood components. In the future, the safety of blood components may be increased by testing donated blood by nucleic acid amplification techniques and by photochemical decontamination of cellular blood components.

Bacterial Infections↗
PubMed1998

Donor selection: the exclusion of high risk donors?

Selection of donors is an important means to improve the overall safety of the blood supply. Since the AIDS epidemic emerged and after the introduction of sensitive screening tests for HIV, it became clear that blood donations given in the infectious 'window' period, formed the most important risk for recipients of blood products. Therefore, selection criteria became more and more stringent to exclude these high risk donors. Means to exclude high risk donors are non-remuneration, including a clear policy to provide no incentives which can be readily converted to cash, the avoidance of replacement donations, the discouragement of 'HIV test seeking' donors, education and information of donors about HIV and other blood-borne infectious diseases and the in depth questioning about risk behaviour, orally as well as by questionnaires. Although this policy of donor selection is recognized by most blood centers in the world, the efficacy of this selection has not been well documented. Therefore in future, studies should be performed to base these selection criteria on evidence.

AIDS Serodiagnosis↗
PubMed1997

Look-back of anti-HCV ELISA-positive, HCV-RNA PCR-negative donors and recipients of their blood products.

BACKGROUND AND OBJECTIVES: To establish the infectivity of anti-HCV ELISA-positive, but cDNA-PCR-negative blood components transfused before the introduction of routine anti-HCV blood donor screening, we enrolled recipients of such blood products in a look-back programme. MATERIALS AND METHODS: The blood components were donated by (A) RIBA-2-indeterminate and cDNA-PCR-negative donors, and (B) RIBA-2 and cDNA-PCR-negative donors. The look-back comprised 214 blood products from group A donors and 278 from group B. RESULTS: Of 211 recipients of group A components, 66 (31.3%) were available for testing. All other recipients could not be traced, had died, or refused collaboration. Of these 66, 3 patients had independent risk factors for HCV infection and were excluded. All remaining 63 recipients were anti-HCV ELISA-negative. Of 274 recipients of group B components, 84 (30.7%) were available for testing. All others could not be traced, had died, or refused collaboration. Of these 84, six patients had an independent risk factor for HCV infection and were excluded. All remaining 78 recipients were anti-HCV ELISA-negative. None of the recipients of blood products from previous donations of anti-HCV ELISA-positive, cDNA-PCR-negative, and RIBA-2-indeterminate or negative donors were HCV-infected. CONCLUSIONS: Donors and patients with such reactivities in anti-HCV ELISA, RIBA-2, and cDNA-PCR can be assured that they are not infected with HCV. The donors involved can re-enter the donor pool, provided that future donations are anti-HCV ELISA-negative.

Antigens, Viral↗
PubMed1997

Evaluation of a new HTLV-I/II polymerase chain reaction.

AIM: Evaluation of a qualitative HTLV-I/II DNA polymerase chain reaction (PCR) test for the detection of HTLV-I/II DNA (Roche Diagnostic Systems, Branchburg, N.J., USA) in various panels. METHODS: The panels consisted of fresh EDTA blood samples from blood donors who were anti-HTLV-I/II ELISA repeatably reactive: 53 were Western blot (WB) positive, 228 were WB indeterminate and 15 were WB negative. Elevent ELISA-negative blood donors were used as negative controls. Furthermore, specimens from 1 HTLV-II-infected intravenous drug user and from 1 HTLV-II-infected blood donor were included in the panel. Peripheral blood lymphocytes were prepared by red blood cell lysis with the Roche washing solution and stored at < -23 degrees C until processing. Amplification products were analyzed with the HTLV-I/II detection kit. RESULTS: All 53 anti-HTLV-I/II ELISA- and WB-positive samples and both HTLV-II-positive samples tested positively by PCR. All 228 anti-HTLV-I/II ELISA-positive and WB-indeterminate, all 15 ELISA-positive and WB-negative and all II ELISA-negative control samples tested negative by PCR. CONCLUSION: The Roche Amplicor HTLV-I/II test is a simple test, suitable for the confirmation of HTLV-I and-II infection in individuals with indeterminate or positive WB patterns.

Blood Donors↗
PubMed1997

Performance of three generations of anti-hepatitis C virus enzyme-linked immunosorbent assays in donors and patients.

BACKGROUND: Prevention of posttransfusion non-A,non-B hepatitis in recipients of blood components improved considerably with the introduction of the second-generation of hepatitis C virus (HCV) antibody tests. In 1993, third-generation HCV antibody assays were introduced in Europe. STUDY DESIGN AND METHODS: The performance of three generations of anti-HCV enzyme-linked immunosorbent assay (ELISA) (ELISA-1, -2, -3) was compared in routine blood donor screening (99,394 donations were tested with ELISA-1, 167,999 donations with ELISA-2, and 262,090 donations with ELISA-3) and in serial samples from nine patients with documented acute posttransfusion HCV infection. RESULTS: Eight (0.01%) repeat donors, previously negative in ELISA-1, were found positive in ELISA-2 and were confirmed as positive in second-generation recombinant immunoblot assay and/or cDNA polymerase chain reaction. In the donor population, no difference in the sensitivity of ELISA-2 and -3 was observed. The specificity of the three generations of ELISAs was comparable (99.8, 99.7, and 99.7%). In seroconversion samples, ELISA-2 and -3 detected HCV antibodies at the same time in seven patients, but in two patients, ELISA-3 found HCV antibodies, respectively, 63 and 77 days earlier than ELISA-2 did. In the seroconversion samples, ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays. CONCLUSION: ELISA-3 did not detect more HCV-infected individuals in a donor population that previously tested negative in ELISA-2, but it did detect HCV antibodies earlier in some patients with acute HCV infection. ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays.

Blood Donors↗
PubMed1996

Sensitivity and specificity of four assays to detect human T-lymphotropic virus type I or type I/II antibodies.

BACKGROUND: Assays that detect human T-lymphotropic virus type I and type II antibody (HTLV-I/II) are widely used in the routine screening of blood donors. STUDY DESIGN AND METHODS: Four commercially available anti-HTLV-I (Fujirebio and Organon Teknika) or -HTLV-I/II assays (Murex and Ortho) were evaluated in various serum panels: A) HTLV-I-positive specimens (n = 41), confirmed by Western blot and polymerase chain reaction; B) a commercially available anti-HTLV-I/II panel; C) serial dilutions of sera from HTLV-I-positive individuals (n = 30), confirmed by immunofluorescence assay and Western blot: D) serial dilutions of HTLV-II-positive blood donors (n = 20), confirmed by Western blot and polymerase chain reaction, and E) sera from first-time blood donors (n = 1055). RESULTS: All four assays elicited reactions in all 82 HTLV-I-positive samples in Panels A, B, and C. Of 32 HTLV-II-positive specimens in Panels B and D, 31 (96.9%) reacted in the Organon Teknika assay and all 32 reacted in the remaining tests. Probit analysis of test results in Panels C and D indicated that the Fujirebio test was the most sensitive assay, followed by Organon Teknika, Ortho, and Murex. The specificities of Fujirebio, Murex, Organon Teknika, and Ortho tests in 1055 first-time blood donors were 99.9, 100, 99.6, and 99.9 percent, respectively. CONCLUSION: All four studied assays for detecting HTLV-I or HTLV-I/II antibodies are appropriate as screening tests.

Blood Donors↗
PubMed1996

New strip immunoblot for the confirmation of HTLV-I/II infection.

In The Netherlands, anti-human T-cell lymphotropic virus type I (HTLV-I) blood donor screening became mandatory in January 1993. Donations reactive in the enzymelinked immunosorbent assay (ELISA) screening test are confirmed with Western blot analysis (WB). Only WB-positive or indeterminate blood donors are notified and retested by polymerase chain reaction (PCR) [1]. In accumulated data of the Dutch Blood Banks, only 2% of donors repeatedly positive in the anti-HTLV-I/II ELISA were WB-positive and all of these were also PCR-positive. However, 75% of the ELISA-positive blood donors have indeterminate WB results. In these cases the ELISA reactivities are nonspecific since all WB-indeterminate donors are negative in PCR [2]. Current WB confirmation thus leads to the notification and often to the deferral of many WB-indeterminate blood donors as well as to high costs for PCR testing, illustrating the need for a more specific serological confirmatory assay. The aim of our study was to evaluate a newly developed anti-HTLV-I/II Recombinant Immunoblot Assay (RIBA) to confirm samples reactive to screening tests with a special emphasis on the ability of this test to resolve WB-indeterminate results in blood donors, without compromising the sensitivity.

Blotting, Western↗
PubMed1995

Look-back study of infectivity of anti-HCV ELISA-positive blood components.

The infectivity of blood components from donors who were later found to be anti-HCV ELISA-positive was investigated in recipients who were enrolled in a look-back programme. Recipients received ELISA-positive blood components from donors who were PCR-positive and/or RIBA-2-positive (n = 22, group A) or PCR-negative and indeterminate or negative on RIBA-2 (n = 105, group B). 26 of 32 (81%) recipients of group A donors and none of 140 of group B were HCV-infected. All stored serum samples of previous donations (n = 172) of group A donors were anti-HCV-positive in RIBA-3, indicating a chronic carrier state of HCV in these donors.

Blood Donors↗
PubMed1995

Comparison of two anti-hepatitis C virus enzyme-linked immunosorbent assays.

BACKGROUND: Third-generation anti-hepatitis C virus (HCV) enzyme-linked immunosorbent assays (ELISA) are now implemented in most laboratories in Europe, but have not yet been fully implemented in the United States. STUDY DESIGN AND METHODS: Two ELISAs (Ortho 3.0 and Ortho 2.0, Ortho Diagnostics, Raritan, NJ) were compared by tests on various serum panels: A) blood donor samples (n = 530) that tested positive in first- or second-generation anti-HCV ELISA; B) samples from persons with chronic non-A, non-B hepatitis (n = 185); C) samples from multiply transfused patients (n = 79); D) samples from patients on hemodialysis (n = 473); and E) samples from Dutch random blood donors (n = 2153). RESULTS: In panels A, B, and C, 247 (100%) of 247 polymerase chain reaction (PCR)-positive and 278 (100%) of 278 second-generation recombinant immunoblot assay (RIBA-2)-positive specimens were detected by Ortho 2.0 and 3.0 (sensitivity, 100%). In the sera of panel D, used to represent a group of patients with a high risk for HCV, no additional positives were found by Ortho 3.0. In panel E, of 2153 blood donor samples, 2 (0.1%) were positive in Ortho 2.0 and 8 (0.4%) in Ortho 3.0. Two samples that were positive in both Ortho 2.0 and 3.0 were also positive in RIBA-2; one was positive on PCR. From the 6 remaining Ortho 3.0-positive (Ortho 2.0-negative) samples, 1 was positive in RIBA-2 (isolated anti-c100) and 3 were positive in third-generation RIBA (1/3 isolated anti-c100, 2/3 isolated NS5). All 6 samples were PCR negative. In first-time donors, no difference in specificity was found. CONCLUSION: The sensitivity and specificity of the Ortho 3.0 ELISA are comparable to those of the Ortho 2.0 ELISA.

Enzyme-Linked Immunosorbent Assay↗