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H W Reesink

Publications and source records attributed to H W Reesink.

At least 109 records · Page 6Linked to original sources
PubMed1994

In vitro evaluation of platelet concentrates, prepared from pooled buffy coats, stored for 8 days after filtration.

BACKGROUND: Posttransfusion complications can be prevented by pretransfusion removal of donor white cells from platelet concentrate. The filtration used for this removal seems to have little effect on platelet function and activation, but more information is needed on its effect on function during subsequent long-term storage of concentrate. STUDY DESIGN AND METHODS: The effect of prestorage filtration of buffy coat-prepared platelet concentrates (PCs) on platelet function, metabolism, and activation was investigated. A pool of three PCs, each made of four buffy coats, was split into three equal volumes; two were filtered over two different filters and the third served as a control. Variables monitored immediately after filtration and during the subsequent 8-day storage period at 22 degrees C included aggregation upon stimulation with collagen and/or ADP, platelet adhesion capacity to collagen and fibrinogen in flowing blood, nucleotide content of and nucleobase release by the platelets, expression of activation-dependent antigens, and beta-thromboglobulin release by the platelets. RESULTS: No differences were observed between the PCs filtered over two different filters and the nonfiltered control PCs immediately after filtration and during storage, except for a selective removal (20%) of beta-thromboglobulin by one filter. CONCLUSION: PCs prepared from a pool of four buffy coats can be filtered and subsequently stored for 8 days (starting +/- 24 hours after whole blood collection) without detriment to platelet function, metabolism, or activation.

Antibodies, Monoclonal↗
PubMed1994

Detection of HIV-1 DNA in leukocytes using a commercially available assay.

Recently, an assay for detection of proviral HIV-1 DNA in leukocytes became commercially available. This assay (Amplicor HIV-1 test, Roche Diagnostic Systems) multiplies HIV-1DNA up to a detectable level, using the polymerase chain reaction. We studied performance of this assay on 74 samples from HIV-1-infected patients and on 41 samples from healthy blood donors. Twice a negative control sample appeared to be erroneously reactive. However, sensitivity and specificity on the patient and donor samples both were 100%. To avoid false-positive results, we advise to repeat initially reactive samples if no other data confirm HIV-infection.

Blood Donors↗
PubMed1994

Effect of filtration on subsequently stored platelet concentrates.

The effect of filtration on the quality of platelet concentrates (PC) during storage was investigated. Two leukocyte depletion filters (Pall PL50HF and Sepacell PL-10A) were applied to filter PC made from a pool of 4 buffy coats. For each experiment 3 PC were pooled and divided into 3 identical PC to eliminate differences between the PC. Two PC were filtered, and the third PC served as an unfiltered control. A total of 12 experiments was performed. Before filtration, volumes of the PC were 263 +/- 11.7 ml (mean +/- SD). Platelet and leukocyte counts per PC were 241 +/- 25.9 x 10(9) and 7.2 +/- 1.8 x 10(6), respectively. After filtration leukocyte counts did not exceed 5 x 10(4) in any of the PC. In the PC filtered with the Pall PL50HF the mean platelet loss was approximately 14% and with the Sepacell PL-10A, 17%. During a 9-day storage period the pH, PO2, PCO2, bicarbonate, lactate and glucose concentration and LDH release as well as the morphology, examined by the swirling effect and microscopically, were not significantly different in filtered and unfiltered units. Filtration through the 2 investigated leukocyte depletion filters for PC did not adversely affect in vitro viability of the platelets during storage.

Bicarbonates↗
PubMed1993

Sexual transmission of hepatitis C virus.

We tested 50 heterosexual partners of hepatitis C viraemic (HCV) individuals, using second generation HCV antibody assays and a validated polymerase chain reaction assay. In none of them were HCV antibodies or HCV-RNA detected. The median duration of the sexual relationship was 13 years. This study, with the most sensitive techniques for detection of HCV, indicates that the risk of sexual transmission of HCV is absent or very low.

Adolescent↗
PubMed1993

Reliability of polymerase chain reaction for detection of hepatitis C virus.

The polymerase chain reaction (PCR) is used to detect hepatitis C virus (HCV) RNA, and the results of this assay may have a bearing on management of patients. We tested 31 laboratories for performance of HCV PCR with a coded panel that comprised 4 HCV-positive plasma samples, 6 HCV-negative samples, and two dilution series of HCV-positive plasma. 15 (48%) laboratories had faultless results with both dilution series, and 16 (52%) laboratories reported erroneous results with one or both series. 10 (32%) laboratories had faultless results when testing undiluted plasma samples, 11 (35%) produced a false-negative result with a weak-positive sample, and 10 (32%) produced false negative and/or false positive results. Only 5 (16%) laboratories performed faultlessly with the entire panel of samples. Reports of presence of HCV should be interpreted with care until reliable HCV-RNA detection becomes widely available.

Clinical Laboratory Techniques↗
PubMed1993

Variability of IgM response in hepatitis C virus infection.

The IgM and IgG antibody response to various hepatitis C virus (HCV) antigens was studied in 8 patients who acquired posttransfusion HCV infection. IgM anti-HCV was detectable in only 4 of these patients, coincident with (1 patient) or later than (3 patients) the IgG anti-HCV response. Seven patients had initially decreasing IgG anti-HCV titres, indicating passive transfer of antibodies from donor to recipient. All 8 patients showed active IgG seroconversion, as demonstrated by increasing IgG anti-HCV titres, on average, 75 days after infection. Five years after infection, all patients were still reactive for IgG anti-HCV antibodies and 7 were positive for HCV RNA by the polymerase chain reaction (PCR). Two of these PCR positive patients were also reactive for IgM anti-HCV. It is concluded that the serology of HCV infection does not follow the classical pattern of IgM response preceding detection of IgG. The IgM response may be absent, late, or persistent after HCV infection. The serological diagnosis of recent HCV infection should be based on the polymerase chain reaction or rising IgG titres in at least 2 sequential patient blood samples.

Antigens, Viral↗
PubMed1993

Recombinant immunoblot assay reaction patterns and hepatitis C virus RNA in blood donors and non-A, non-B hepatitis patients.

To establish the value of the second-generation recombinant immunoblot assay (RIBA-2) and cDNA polymerase chain reaction (cDNA PCR) for confirmation of hepatitis C virus (HCV) infection, anti-HCV reaction patterns and the presence of HCV RNA were examined in 610 blood donors and 255 non-A, non-B hepatitis patients who were positive or indeterminate in RIBA-2. Of RIBA-2-positive donors (n = 191) and patients (n = 224), 75.4 and 89.7 percent, respectively, were HCV RNA positive. The most frequently observed anti-HCV recognition patterns in HCV RNA-positive donors and patients were c22, c33c, and c100 and/or 5-1-1 (67.3%, 57.7%) and c22, c33c (24.8%, 29.3%). Among subjects with a RIBA-2-indeterminate result, HCV RNA was detected more often in patients (n = 31) than in donors (n = 419): 67.7 and 2.1 percent, respectively. In viremic persons with single-band reactivity in RIBA-2, this reactivity was always directed against either c22 or c33c. HCV RNA was detected by cDNA PCR in none of 162 persons with only anti-c100 and/or anti-5-1-1 reactivity. Therefore, RIBA-2 reactivity against c100 in combination with 5-1-1 should not be considered positive but indeterminate. In RIBA-2-indeterminate persons, HCV RNA detection is necessary for reliable confirmation of HCV infection.

Blood Donors↗
PubMed1993

Long term treatment of chronic hepatitis C with interferon alfa-2b: disappearance of HCV-RNA in a pilot study of eight haemophilia patients.

This pilot study was designed to establish the effect of long term alpha interferon treatment in haemophilia patients with chronic hepatitis C. Overall, three of eight (37.5%) patients showed a complete response, three of eight (37.5%) a transient response, and two of eight (25.0%) no response. HCV-RNA detection by polymerase chain reaction was more sensitive in detecting relapse than alanine amino-transferase (ALT) activity measurement, suggesting that current interferon schedules based on the ALT response should be re-evaluated critically.

Chronic Disease↗
PubMed1993

Testing for HCV markers.

Until 1988 the putative agent of non-A/non-B (NANB) hepatitis had not been found. Research workers of the Chiron Corporation (California, USA) then identified, by "blind expression cloning", polypeptides which specifically bound antibodies present in sera of NANB-patients. A fusion polypeptide (C-100) was expressed in yeast. With the C-100 antigen prototype RIA and ELISA antibody tests were developed. Subsequently more polypeptides (C-200, C33c, C22) of the HCV-genome were added to the test system, resulting in second generation anti-HCV tests with increased sensitivity. For confirmation of HCV ELISA reactive samples, recombinant immunoblot (RIBA-2, Ortho; Innolia, Innogenetics) and dot immunoblot assays (Matrix, Abbott) were developed. Detection of HCV antigens has been hampered by the low virus titres in serum and the absence of free circulating viral antigen(s). However, with cDNA-PCR, applying primers of the highly (> 93% nucleotide homology) conserved 5' untranslated (5'UTR) region of the HCV genome, HCV-RNA in serum as well as in liver tissue can be detected. cDNA-PCR, although not yet commercially available, is useful to confirm HCV-viremia in patients. When chronic hepatitic C patients are treated with anti-viral drugs, the disappearance of HCV-RNA, as detected by PCR, is a measure of therapy response.

Antigens, Viral↗
PubMed1992

Prevention of Yersinia enterocolitica growth in red-blood-cell concentrates.

In response to concern about Yersinia enterocolitica contamination of blood products, we have studied the effects on Y enterocolitica growth of holding whole blood at 22 degrees C for 20 h and then removing leucocytes. Thirty pools of three bags of blood were inoculated with Y enterocolitica (2 x 10(1)-3 x 10(4) colony-forming units/ml). One bag in each pool was processed to red-blood-cell concentrate after 6 h at 4 degrees C (RBC); the other two were held at 22 degrees C for 20 h before processing to buffy-coat-depleted RBC (BCd-RBC). One of these bags was then depleted of leucocytes by filtration (Ld-RBC). All bags were stored at 4 degrees C for 5 weeks. RBC bags showed Y enterocolitica growth after the shortest storage times, followed by BCd-RBC then Ld-RBC (p less than 0.03-0.001). We recommend that whole blood should be held at 22 degrees C to make use of inherent bactericidal activity; leucocytes should then be removed.

Blood Bactericidal Activity↗
PubMed1992

Sensitivity of an anti-HCV core peptide ELISA.

A newly developed antibody assay based on a synthetic peptide of 15 amino acids derived from the core region of the hepatitis C virus (HCV) genome was evaluated in serum and plasma panels of (A) 225 haemophiliacs and (B) 44 patients with chronic non-A, non-B (NANB) hepatitis, and in (C) sequential serum samples of 9 patients with transfusion transmitted HCV infection. The new anti-core peptide ELISA was compared with the anti-C100 ELISA. For confirmation of HCV infection, samples were tested in a 4-antigen recombinant immunoblot assay (4-RIBA) and samples of panels B and C were also assayed in cDNA-polymerase chain reaction (PCR). In two panels with a high prevalence of HCV infection (88.4 and 70.5% in haemophilia and NANB hepatitis patients, respectively), the sensitivity of the anti-core peptide ELISA did not differ significantly from the sensitivity of the anti-C100 ELISA. The sensitivity of the new assay as compared with the anti-C100 assay was found to be 0.84 [95% confidence interval (CI): 0.78-0.89] versus 0.92 (95% CI: 0.87-0.95) in haemophilia patients and 0.71 (95% CI: 0.52-0.86) versus 0.84 (95% CI: 0.66-0.95) in NANB hepatitis patients. In sequential serum samples of patients with transfusion-transmitted HCV infection antibodies to the core peptide (in 6/9 patients) appeared later than antibodies to C100 (in 7/9 patients): 168 (range: 70-322) and 143 (range: 59-365) days after transfusion, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Patterns of serological markers in transfusion-transmitted hepatitis C virus infection using second-generation HCV assays.

A semiautomated dot blot assay and cDNA polymerase chain reaction (PCR) were used to study longitudinal anti-hepatitis C virus (HCV) recognition patterns in relation to presence of HCV-RNA in transfusion recipients and their infectious donors. In 9 recipients, 4 different patterns of HCV infection were observed: (A) persistent HCV carriage accompanied by chronic hepatitis in 6, (B) acute resolved hepatitis, but persistent HCV replication in one, and (C) continuous HCV replication without hepatitis in one and (D) acute resolved hepatitis with clearance of infection in one. This last self-limited infection was characterized by the disappearance of HCV-RNA as well as anti-HCV reactivity. In contrast, antibody reactivity persisted in 7 of 8 patients with chronic HCV infection who could be followed until 1990. Seven of the 9 recipients developed antibodies to all recombinant peptides in dot blot assay; one became positive for anti-C33 and anti-core and one developed anti-core only. The sequence of appearance of antibodies differed among individual patients. In 7 patients with full anti-HCV recognition patterns, the sequence of events was (mean and limits in days after transfusion): onset of hepatitis at day 50 (22-74), seroconversion of anti-C33 at day 91 (59-129), anti-core at day 133 (54-203), and anti-C100 at day 143 (59-365). The incorporation of C33 and core proteins, in addition to C100, in the second generation anti-HCV ELISA enhanced the detection rate in the HCV-infected transfusion recipients from 7/9 (78%) to 9/9 (100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers↗
PubMed1992

HCV and blood transfusion.

Posttransfusion hepatitis remains a threat to transfusion therapy. Testing for increased ALT levels has been used in an attempt to reduce this risk. Presence of the infectious agent, hepatitis C virus (HCV), appears to be a much more sensitive criterion. Stored serum samples from transfusion blood as well as recipients of transfusion were tested by ELISA, RIBA and PCR for the presence of HCV. The results show that RIBA and PCR are about equally sensitive and are able to detect HCV positivity in many sera that might have been otherwise transfused. Routine screening for the presence of virus will dramatically reduce the danger of hepatitis infection to transfusion patients.

Blotting, Western↗