Biomedical subjects

F Hulstaert

Publications and source records attributed to F Hulstaert.

28 records · Page 2Linked to original sources

PubMed1994

Age-related changes in human blood lymphocyte subpopulations. II. Varying kinetics of percentage and absolute count measurements.

A reference range for lymphocyte populations, with particular emphasis on T lymphocyte subsets, was obtained for normal individuals covering age cohorts from birth through adulthood. This report confirms and extends findings from a developmental reference range published earlier (1). Absolute numbers of WBC, lymphocytes, and T, B, and NK subsets decline significantly during childhood. However, differences in the rate of decline of certain lymphocyte subsets leads to discordance between absolute numbers and percentages. Those lymphocyte subsets which decline less rapidly with age than the total lymphocyte count will show an increase in percentage, whereas those which decline more rapidly will show further declines in percentage values. T cell percentages were seen to increase over time whereas B cell percentages decline. Markers of immaturity such as CD45RA on CD4 cells and CD38 on CD8 cells declined in both percentages and absolute numbers. Activation markers, such as HLA-DR on CD8 cells and IL2-R on CD3 cells, increased in percentages with time but changed inconsistently in cell number from infancy to adulthood. These findings extend the lymphocyte references range to markers thought to be informative in various disease states, including HIV infection.

Adolescent↗

PubMed1994

Optimal combination therapy with tropisetron in 445 patients with incomplete control of chemotherapy-induced nausea and vomiting.

PURPOSE: This study evaluated tropisetron (Navoban; Sandoz Pharma, Basle, Switzerland)-based combination therapy in patients who had incomplete control of chemotherapy-induced nausea or vomiting when using tropisetron as a single antiemetic agent. PATIENTS AND METHODS: One thousand seventy-two patients, who were scheduled to receive at least two identical cycles of emetogenic chemotherapy, were treated with 5 mg tropisetron once daily in their first chemotherapy course. A 2 x 2 x 2 factorial design was used to evaluate three additional treatments to the recommended 5 mg once daily (intravenously [i.v.] on day 1; orally on days 2 through 6) tropisetron regimen during course 2 in those patients who had shown incomplete control of nausea and/or vomiting on any day of course 1. Four hundred forty-five patients were centrally randomized to receive, in addition, open-label dexamethasone (day 1, 0.2 mg/kg i.v.; days 2 through 6, 8 mg orally) and/or open-label alizapride (day 1, 100 mg i.v. and 4 x 50 mg orally; days 2 through 6, 4 x 50 mg orally) and/or double-blind tropisetron (ie, doubling the dose to 10 mg once daily) or corresponding placebo. RESULTS: Complete response rates (no nausea and no vomiting) were 72% for day 1 and 48% for days 1 through 6 of course 1. During course 2, more complete responders were observed when dexamethasone was added, both for day 1 (76% v 66%, P = .020) and for days 1 through 6 (50% v 34%, P = .0004). A moderate increase in the complete response rate was seen with the addition of conventional-dose alizapride (day 1, 75% v 68%, P = .14; days 1 through 6: 47% v 37%, P = .041). Doubling the dose of tropisetron did not change the complete response rate. CONCLUSION: The addition of dexamethasone significantly increases the complete response rate of both acute and delayed emesis in patients who have incomplete disease control with tropisetron alone.

Administration, Oral↗

PubMed1992

Age-related changes in human blood lymphocyte subpopulations.

Flow cytometric analysis of major lymphocyte populations and their subsets reveals age-related changes in the cellular human immune system. Immunophenotypic markers were evaluated in 110 normal pediatric subjects, divided into groups of newborn infants, infants aged 2 days to 11 months, and children aged 1 to 6 years and 7 to 17 years; results were then compared with those obtained from 101 normal adults aged 18 to 70 years. Comparisons among age groups from newborn infants through adults reveal progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells within the total lymphocyte population increase with age, in both CD4+ and CD8+ subsets. Percentages of B and NK cells are higher in newborn infants than in adults. The expression of the activation markers interleukin-2R and HLA-DR on T cells increases with age, as does the NK-associated expression of CD57 on CD8 cells. The proportions of B lymphocytes that coexpress CD5 or CDw78 decrease with age, whereas expression of Leu-8 and CD23 increases. The proportion of CD4 cells bearing the CD45RA and Leu-8 markers is consistently lower in adults than in children. These data may serve as a reference range for studies of pediatric subjects.

Adolescent↗

PubMed1992

Expression of activation antigens, HLA-DR and CD38, on CD8 lymphocytes during HIV-1 infection.

OBJECTIVE: To study the expression of the activation markers human leukocyte antigen (HLA)-DR and CD38 antigen on CD8+ T-lymphocytes in HIV-infected subjects and HIV-negative controls. DESIGN: Two- and three-colour flow-cytometric analysis. METHODS: Fresh peripheral venous blood was obtained from 16 HIV-infected subjects, representing four different stages of HIV disease, and from six HIV-negative controls. Three-colour lymphocyte immunophenotyping was performed using peridinyl chlorophyll-A protein (PerCP)-conjugated anti-CD8 monoclonal antibody (MAb) in combination with anti-HLA-DR (phycoerythrin) and anti-CD38 (fluorescein isothiocyanate) MAb. RESULTS: The relative percentage of the lymphocyte populations thus defined differed between HIV-negative and HIV-positive subjects and between HIV-infected subjects at different clinical stages of disease. Simultaneous expression of HLA-DR and CD38 within the CD8 T-lymphocyte compartment increased from 8% in controls to 49% in asymptomatic HIV-infected subjects (P less than 0.005). Symptomatic patients differed from asymptomatic seropositives by a further increase in the HLA-DR+ CD38+ CD8 subset. In AIDS patients, the HLA-DR+ CD38- CD8 subset decreased (P less than 0.05) and the HLA-DR- CD38+ CD8 subset increased (P less than 0.05), compared with the other HIV disease stage patients. CONCLUSION: There is a stage-associated pattern of HLA-DR and CD38 expression on CD8 T-lymphocytes during HIV infection; specific phenotypic patterns may have functional correlates in the host response to the virus.

ADP-ribosyl Cyclase↗

PubMed1992

The significance of activation markers on CD8 lymphocytes in human immunodeficiency syndrome: staging and prognostic value.

The objective of this prospective cohort study was to evaluate the expression of activation markers on CD8 lymphocytes at various clinical stages of HIV infection and to determine the value of these markers in identifying patients likely to have rapidly progressive disease. One hundred and three HIV+ patients, divided into four disease stages, and 34 seronegative controls were evaluated at study entry using flow cytometric immunophenotyping. The HIV patients were followed clinically for disease progression during the following 2 years. CD8 cell numbers and percentage of lymphocytes are increased after HIV infection. Expression of the CD38, HLA-DR and CD57 markers on CD8 cells was significantly increased in asymptomatic HIV-infected patients when compared with controls, as was the CD8 cell population which did not coexpress Leu-8. These activation markers were observed to be further increased in patient groups with more clinically advanced infection. The percentage of CD38 on CD8 cells emerged not only as a discriminator of disease severity, but was a strong predictor of progression in asymptomatic, lymphadenopathy and ARC patients. Given the utility of activation markers on CD8 lymphocytes in staging disease and predicting clinical outcome, the measurement of these parameters should be considered in the monitoring and management of HIV patients.

AIDS-Related Complex↗

PubMed1991

Flow cytometric analysis of peripheral blood lymphocytes in ulcerative colitis and Crohn's disease.

Using two colour immunofluorescence with fluorescein isothiocyanate and phycoerythrin labelled monoclonal antibodies, multi-parameter flow cytometry was used to examine the antigenic characteristics of peripheral blood lymphocytes in whole blood of patients with ulcerative colitis and Crohn's disease who were not taking immunosuppressive drugs. The numbers of CD4+ and CD8+ lymphocytes in patients with ulcerative colitis and Crohn's disease remained unchanged so that the CD4/CD8 ratio was the same as that of normal control subjects. In Crohn's disease there were many activated T cells (CD3+, CD25+). Although natural killer cells in active Crohn's disease were lower than in normal control subjects, cytotoxic T lymphocytes, as defined by CD3+, CD16+, did not differ in patients with inflammatory bowel disease compared with normal control subjects. For B cell subsets, there were differences in Leu-1+ B cells, Leu-8+ B cells, Fc epsilon R+B cells (Leu-16+, Leu-20+), and activated B cells (Leu-12+, Leu-21+) between patients with inflammatory bowel disease and normal control subjects. These differences are compatible with local activation of B cells in the inflamed colon.

Adolescent↗

PubMed1987

Distribution and composition of HDL subclasses in students whose parents suffered prematurely from a myocardial infarction in comparison with controls.

The purpose of this study was to analyze the distribution and composition of the HDL subclasses in students whose parents suffered from a premature coronary heart disease (CHD), in comparison with a control group without any familial history of CHD. In the first part of this study, we observed significantly lower apo A-I concentrations in the cases than in the controls. Since there was a significant difference in smoking habits between cases and controls, and since we wanted to study the effect of a parental history of premature CHD on the composition of the HDL subclasses independently of smoking, the present study was conducted on the 17 pairs of non-smokers male cases and controls. In agreement with the results on total serum, we observed lower apo A-I concentrations in the HDL2b and HDL2a + 3a fractions in the cases compared to the controls. The apo A-II and cholesterol levels in these fractions were not significantly different between the 2 groups. The selective decrease of apo A-I in the HDL subclasses with the lowest density might be due to a decreased number of particles containing only apo A-I, with which a protective effect against atherosclerosis might be associated.

Adult↗

PubMed1986

Serum lipids and apoproteins in students whose parents suffered prematurely from a myocardial infarction.

Lipids and apoproteins as well as other coronary risk factors were measured in offspring of patients who suffered from a myocardial infarction before the age of 50 years; the results are compared with the results of a control group matched for age and sex. Significant differences were observed in the apoprotein A1 level, in the protein/fat ratios of high- and low-density lipoproteins, and in smoking habits. In a multivariate analysis, the offspring group was found to be different from the control group in nonhigh-density lipoprotein cholesterol/apoprotein B ratio, high-density lipoprotein cholesterol/apoprotein A1 ratio, smoking habits, apoprotein A1, and apoprotein A2. By means of these variables a total of 85% of all subjects could be correctly classified. We conclude that as early as age 21 years the offspring of patients with premature coronary heart disease differ from matched control subjects in lipoprotein measurements and in smoking habits.

Adult↗

PubMedDate not supplied

Two-color immunofluorescence and flow cytometric analysis of peripheral blood lymphocyte subsets in Caucasian and Japanese healthy subjects.

Two-color immunofluorescence using multiparameter flow cytometry was employed to examine the antigenic characteristics of peripheral blood lymphocytes in whole blood of healthy Caucasians and Japanese. The CD4/CD8 ratio in Japanese was significantly decreased compared with that in Caucasians, because of the increased number of CD8+ cells. Although the proportions of suppressor-inducer T cells (CD4+, Leu-8+) and helper-inducer T cells (naive T cells) (CD4+, CD45RA-) were low in Japanese subjects, there were no differences in the absolute numbers of suppressor-inducer T cells and helper-inducer T cells (naive T cells) in circulation. The level of activated T cells in Japanese was similar to that in Caucasians. NK cells, CD57+, CD8+ cells and CD57+, CD3+ cells were high in Japanese. Regarding B cell subsets, CD5+ B cells and activated B cells remained unchanged. However, there were slight differences in Leu-8+ B cells and Fc epsilon R+ B cells (CD20+, CD23+) between the two groups. Thus, a differing influence of racial and environmental background between healthy Caucasians and healthy Japanese on human lymphocyte subsets is present in the lymphocyte immunophenotype.

Adult↗

PubMedDate not supplied

Clinical optimization and multicenter validation of antigen-specific cut-off values on the INNO-LIA ANA update for the detection of autoantibodies in connective tissue disorders.

OBJECTIVES: The INNO-LIA ANA Update is a qualitative multiparameter line immunoassay for detection of autoantibodies to several different antigens associated with connective tissue disorders. We sought to optimize and validate the cut-off values for its antigen-specific components: SmB, SmD, RNP-70k, RNP-A, RNP-C, SSA/Ro52, SSA/Ro60, SSB/La, Cenp-B, Topo-I, Jo-1, ribosomal P, and histones. Our aim was to achieve 98% specificity for each of the markers, with respect to differential disease controls, while maintaining sensitivity. METHODS: For optimization, the cut-off value of the different antigen lines was fixed to achieve this specificity using an in-house set of 955 patient samples. Specificity was validated at multiple sites using a different set of 330 samples obtained from 158 apparently healthy blood donors, 100 patients with a variety of infections, 20 each with Wegener's granulomatosis, inflammatory bowel disease, and primary antiphospholipid syndrome, and 12 with psoriatic arthritis. Sensitivity was evaluated, using this optimized cut-off control, in 147 patients with scleroderma, 93 with Sjögren's disease, 40 with systemic lupus erythematosus, 40 with rheumatoid arthritis, 39 with mixed connective tissue disease, and 19 with polymyositis. Sensitivity and specificity of the INNO-LIA ANA Update were determined using the clinical diagnosis as reference. RESULTS: The optimized cut-off values resulted in a specificity 98% or more for all LIA markers except one (histones 97.8%) in the validation set of 330 samples. The sensitivity for each marker tested in 378 samples from the target patient groups was comparable to that reported in the literature. CONCLUSION: The INNO-LIA ANA Update shows uniformly high specificities combined with sensitivities very similar to those of reference assays, in a single test format.

Antigens↗