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H L Zaaijer

Publications and source records attributed to H L Zaaijer.

At least 37 records · Page 2Linked to original sources
PubMed1998

High prevalence of parvovirus B19 IgG antibodies among Dutch hemophilia patients.

BACKGROUND AND OBJECTIVES: Human parvovirus B19 is a potential risk to hemophiliac patients receiving blood products. MATERIALS AND METHODS: To determine the prevalence of the corresponding antibody in patients with hemophilia A or B von Willebrand's disease, we tested 326 hemophilia patients for anti-B19 IgG. The results were compared with those of 203 age-matched controls (male blood donors and children). RESULTS: The overall prevalence of B19 IgG in the hemophilia patients was 302/326, and in the controls 123/203. Below the age of 10, hemophilia patients had a higher prevalence of B19 IgG (76%, 42/55) than the controls (23%, 11/48; p < 0.00001). In those below the age of 5 who had been treated exclusively with monoclonally purified concentrate, it made no difference whether the product was pasteurized or solvent-detergent treated. There was significantly lower incidence in patients who were rarely treated. CONCLUSION: Parvovirus B19 if frequently transmitted in blood products. Existing virus-inactivating methods do not prevent transmission.

Adolescent↗
PubMed1997

[Infection with T-lymphotropic virus in Dutch blood donors, 1993-1996].

Infection with human T-lymphotrophic virus (HTLV) type 1 causes a neurological disorder or leukaemia in a minority of infected persons. Since January 1993 the Dutch blood banks screen each donation for presence of HTLV-1 infection. Approximately 4,000,000 donations from 700,000 donors have been tested. The numbers of confirmed HTLV-1 positive donors were: 1993: 15; 1994: 6; 1995: 8; 1996: 3. In 1995 one case of HTLV-2 infection was detected as well. In 26/32 (81%) of the HTLV-1 positive cases either the donor or his/her partner originated from HTLV-1 endemic areas. The introduction of HTLV screening prevents the silent spread of HTLV via blood transfusion.

Blood Donors↗
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

New anti-human immunodeficiency virus immunoblot assays resolve nonspecific western blot results.

BACKGROUND: Two new anti-human immunodeficiency virus type 1 and 2 (HIV-1/2) immunoblot assays, which use recombinant and synthetic antigens for antibody detection have become available. These assays might be able to resolve indeterminate anti-HIV Western blot results. STUDY DESIGN AND METHODS: The new anti-HIV immunoblot assays were used to test 67 samples from 31 HIV infected and 24 noninfected persons showing various anti-HIV Western blot patterns. RESULTS: The immunoblots correctly identified eight HIV-2-positive samples and five late-stage HIV-1-positive samples. After 30 samples from 18 seroconverting persons were tested, the Western blot showed reactivity in 24 of 30 samples and the immunoblots showed reactivity in 21 of 30 samples (difference not significant). In 16 of 30 seroconversion samples, both immunoblot assays produced HIV-1-positive results. In accordance with various criteria for interpretation, the number of positive Western blot results was as follows: Centers for Disease Control and Prevention, 16 of 30 and World Health Organization, 13 of 30. When samples from non-HIV-infected persons were tested, both immunoblot assays resolved 20 (83%) of 24 samples showing indeterminate Western blot reactivity. CONCLUSION: Although the sensitivity of the immunoblot assays should be validation in larger studies, the mere specificity of these assays makes them valuable for the exclusion of HIV infection in Western blot-indeterminate, HIV p24 antigen-negative samples.

Blotting, Western↗
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↗
PubMed1997

Temporary seronegativity in a human immunodeficiency virus type 1-infected man.

Over a period of 3 months a human immunodeficiency virus 1 (HIV-1)-infected patient showed a sequence of positive-negative-positive anti-HIV screening test results. During this period the level of HIV p24 antigen declined and the HIV antibody pattern by Western blot gradually became complete, suggesting recent HIV infection. However the patient's weight loss, esophageal candidiasis, and Pneumocystis carinii pneumonia, together with the severely and persistently lowered CD4 cell counts and the absence of an IgM anti-HIV response, suggest late-stage HIV infection. Despite additional and follow-up testing, it was impossible to determine whether the patient suffered from acute, primary HIV infection with severe immunodepression or from advanced HIV infection (AIDS) with hampered HIV antibody production leading to false-negative test results by the anti-HIV enzyme immunoassay and Western blot. This case illustrates that HIV serology does not always follow the rules. The presence of HIV infection should be considered in a patient showing clinical signs of acute or late-stage HIV infection, even if the anti-HIV assay is negative.

Acquired Immunodeficiency Syndrome↗
PubMed1996

International collaborative study on the second EUROHEP HCV-RNA reference panel.

Eighty-six laboratories participated in a collaborative study and tested the second EUROHEP HCV-RNA reference panel. The coded panel comprised 4 HCV-RNA positive plasma samples (one weak positive), 6 HCV-RNA negative plasma samples and two dilution series of HCV-RNA genotype 1 and 3 plasma standards. The 86 laboratories submitted 136 coded data forms for evaluation. Of these data sets 99 were tested using a PCR assay developed in-house, 28 using a commercially available HCV-PCR test (AMPLICOR, Roche Diagnostic Systems) and 9 using other amplification methods. Twenty-two data forms (16%) had faultless results, 39 (29%) missed the weak positive sample only and 75 data sets (55%) had false positive and/or false negative results. Participants using the commercial HCV-PCR test tended to reach a sufficient quality score more often than investigators using assays developed in-house (64% versus 45%, P = 0.11). The UNG system in the commercial HCV-PCR test did not prevent five laboratories generating false-positive results in the 6 HCV-RNA negative samples. Among the laboratories with satisfactory results, up to 10000-fold differences in sensitivity were observed in the dilution series. The 50% and 90% laboratories detection endpoints in the dilution series of the HCV genotype 1 plasma standard were approximately 600 genome equivalents per ml (geq/ml) and 7750 geq/ml according to a standard applied in a signal amplification assay (bDNA, Chiron). Our results suggest that the detection efficiency for genotype 3 by commercial HCV-RNA assays is lower than by the in-house assays. Internationally characterized HCV-RNA plasma standards should be made available for validation and standardization of HCV-RNA assays for HCV diagnosis and virological safety testing of blood products.

Hepacivirus↗
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

Hepatitis E virus antibodies among patients with hemophilia, blood donors, and hepatitis patients.

The presence of antibodies to hepatitis E virus (HEV) was studied among hemophiliacs, blood donors, and hepatitis patients. Four of 296 (1.4%) hemophiliacs and 5 of 1,275 (0.4%) donors were confirmed as positive for HEV antibodies (difference was not significant: P = 0.07). Parenteral transmission of HEV to hemophiliacs was thus rare or nonexistent. Seven of 187 hepatitis patients were found with HEV antibodies (IgG and IgM). Six persons fell ill shortly after arriving from HEV-endemic countries. The seventh patient, without a history of travel, represents a case of nontropical hepatitis E. Consequently, hepatitis E should be considered in patients suffering from acute non-ABC hepatitis, even in industrialized countries.

Adolescent↗
PubMed1995

Detection of HIV-1 RNA in plasma by isothermal amplification (NASBA) irrespective of the stage of HIV-1 infection.

Using an experimental assay for isothermal amplification of HIV RNA in plasma (NASBA, Organon Teknika, Boxtel, The Netherlands), 70 samples from 59 HIV-1-infected persons and 29 samples from 28 uninfected volunteer blood donors were tested for the presence of HIV-1 RNA. The HIV-1-positive plasma samples were drawn from patients at various stages of infection: two samples from persons with signs of acute HIV infection (CDC stage I); 29 samples from 25 symptom-free persons (CDC stage II) and 39 samples from 32 persons with AIDS-related symptoms (CDC stage IV). All samples from HIV-1-infected persons had HIV-1 RNA, irrespective of the stage of infection (100% sensitivity). Testing the donor samples in duplicate, initially 54/58 samples (93%) tested negative for HIV-1 RNA. Repeated testing of the 4 samples with inconsistent test results showed all samples to be negative (specificity 100%). Detection of HIV-1 RNA in plasma by isothermal amplification (NASBA) promises to be a valuable alternative to the detection of HIV-1 RNA or DNA by the polymerase chain reaction.

Acquired Immunodeficiency Syndrome↗
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↗
PubMed1995

Reliability of the third-generation recombinant immunoblot assay for hepatitis C virus.

BACKGROUND: In a confirmatory laboratory, the second-generation recombinant immunoblot assay (RIBA-2) was replaced by the third-generation RIBA (RIBA-3) in March 1993. The aim of this validation study was to compare the sensitivity and specificity of RIBA-2 and RIBA-3 in a routine setting, by using a validated hepatitis C virus (HCV) RNA polymerase chain reaction to establish plasma viremia. STUDY DESIGN AND METHODS: RIBA-2 testing was performed (March 1991-March 1993) in 593 HCV RNA-positive and 1498 HCV RNA-negative subjects. RIBA-3 testing was performed (March 1993-May 1994) in 220 HCV RNA-positive and 530 HCV RNA-negative subjects. All samples reacted for anti-HCV in enzyme-linked immunosorbent assay. RESULTS: In HCV RNA-positive individuals, the sensitivity of RIBA-3 was significantly higher than that of RIBA-2 (99.5% vs. 93.3%, p = 0.0005). This was not caused by inclusion of the NS5 antigen, but by a higher sensitivity of the antigens c33 and c100 (RIBA-2: 94.3% and 62.6%; RIBA-3: 99.5% and 88.6%). Replacement of the c22 and c100 recombinant proteins by synthetic peptides significantly reduced nonspecific reactivity against these antigens (p < 0.0001). Unfortunately, increased nonspecific reactivity against the modified c33 antigen and the new NS5 antigen canceled out this effect. Two-band reactivity occurred more often in nonviremic persons than in viremic persons (32.7% vs. 8.2%, p < 0.0001). Risk factors for HCV infection were less frequently observed in 11 blood donors with two-band reactivity than in 6 blood donors with other positive RIBA-3 patterns (18% vs. 83%, p = 0.03). CONCLUSION: The higher sensitivity of RIBA-3 significantly reduced the number of indeterminate test results in HCV RNA-positive persons. Confirmatory laboratories must be aware of the frequent occurrence of nonspecific, isolated reactivity and even nonspecific, two-band reactivity in anti-HCV enzyme-linked immunosorbent assay-reactive blood donors.

Hepacivirus↗