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M De Bruyere

Publications and source records attributed to M De Bruyere.

At least 19 recordsLinked to original sources
PubMed2001

Expression of HLA-DR, CAM and co-stimulatory molecules on cord blood monocytes.

Umbilical cord blood (CB) transplantations are associated with a lower risk of severe graft-versus-host disease (GVHD) compared to BMT. GVHD is an immune reaction that involves interaction between cell surface molecules resulting in cell activation and release of many cytokines. Monocytes are known to be an important source of cell adhesion (CAM) and co-stimulatory molecules which play a crucial role in the efficient activation of T and B cells. We analyzed the phenotype of CB monocytes in the presence or absence of an inflammatory signal (rIFN-gamma) and compared them to adult blood (AB); the expression of HLA-DR and 17 different markers (CD11a, CD11b, CD11c, CD18, CD29, CD40, CD44, CD49a, CD49d, CD49e, CD49f, CD54, CD58, CD62L, CD80, CD86 and CD102) was measured by flow cytometry. Statistical analysis showed that, compared to AB, CB monocytes did not express CD11b, CD11c, CD49d and after stimulation with rIFNgamma, they lost the expression of CD58 and CD102, whereas CD80 and CD86 expression was induced. The analysis of fluorescence intensity (MFI) revealed that CB monocytes expressed some CAM (CD29, CD54, CD102) with a lower intensity than AB monocytes except CD44. In conclusion, absence and reduced expression of some markers argue for a different phenotypic profile of CB monocytes compared to AB monocytes, which might partly contribute to their impaired immune response and to the low incidence of GVHD observed after CB transplantations. However, CB monocytes expressed CD80 and CD86 co-stimulatory molecules, but this expression did not prove a normal co-stimulatory function.

Adult↗
PubMed1997

A seroepidemiological study on toxoplasmosis.

Using the microparticle capture enzyme-immunoassay (MEIA) based on IMx technology (Abbott), we determined the current prevalence of toxoplasmosis in 784 pregnant women followed up during 1990, and in 1,839 randomly selected blood donors. They all came from the Brabant Wallon area and the South-East of Brussels. Specimens yielding low IgG immunity (6-15 units) [corrected], were further tested with a sensitive direct agglutination assay (Toxo-Screen DA, bioMerieux). Overall, the prevalence was 67% among blood donors and 50% in pregnant women. In blood donors, the prevalence in women was not statistically different from the prevalence in men: X2 = 2.95 NS. In the two populations, a progressive age-related increasing prevalence of up to 60% for pregnant women and 77% for blood donors was observed. In females, the prevalence was higher among female blood donors than among pregnant women: 63% versus 50%, X2 = 16, P < 0.001. However, when the prevalences were compared within three age subgroups of women (< or = 33 yrs, 34 to 41 yrs, > or = 42 yrs), there were no statistically significant differences between pregnant women and blood donors. Thus, the overall observed difference was due to an age effect. Therefore, the distribution of IgG titers was established in each of the six age and sex subgroups. The 25th, 50th and 75th percentiles of those distributions ranged between 14 IU and 20 IU, 24 IU and 35 IU, and 40 IU and 64 IU, respectively. The annual seroconversion rate was 0.8% in pregnant women, against 0.2% amongst non-immune blood donors over 3 months. In conclusion, our findings confirm the general prevalence of 50% of toxoplasmosis and an annual seroconversion rate of 0.8% in these two populations.

Adult↗
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

Bedside transfusion errors. A prospective survey by the Belgium SAnGUIS Group.

The true incidence of bedside transfusion errors, i.e. those happening when blood products have left the blood bank, is underestimated because published figures rely on reporting of clinically relevant events or on indirect methods. The SAnGUIS project assessing blood practice in a prospective and randomized fashion for 6 elective surgical procedures gave the opportunity to trace all transfused units and to identify steps at risk during blood delivery in surgery. We considered transfusion of a wrong unit as a major error and poor execution or documentation as a recording error. Over 15 months, 808 patients out of 1,448 were transfused with 3,485 units. A total of 165 errors were found after blood products had left the blood banks. Seven were misidentifications (0.74% of patients, 0.2% of units). Eight other major errors occurred in 4 (0.5%) patients. Major errors occurred during nonemergency situations, in wards or intensive care units. The remaining ('recording') 150 errors consisted of misrecordings (61), mislabellings (6), or failures to document transfusions in the medical records (83). All errors were uneventful except one misidentification which induced a transient, yet unreported, reaction. The 'descending' inquiry method used for this study showed that most errors pass unnoticed and are therefore not reported. Measurement of error rates may constitute an important quality indicator. Retrospective information of this survey to the concerned staff people provided an impetus to take adequate measures to reduce these bedside errors.

Belgium↗
PubMed1993

Role of the YadA protein in prevention of opsonization of Yersinia enterocolitica by C3b molecules.

When mixed with normal human serum, wild-type pathogenic Yersinia enterocolitica, previously incubated at 37 degrees C, fixed less C3b than its variant cured of the virulence plasmid pYV. Mutants unable to secrete the Yop proteins were still protected against C3b deposition. By contrast, mutants deficient in the production of outer membrane protein YadA fixed more C3b than their YadA+ parent. Gene yadA, cloned as a minimal polymerase chain reaction fragment and introduced in trans, complemented the mutations. Production of YadA by recombinant Escherichia coli LK111 also resulted in a reduction of the amount of C3b deposited on the bacterial surface. The reduction of C3b at the surface of Y. enterocolitica YadA+ compared with YadA- cells correlated with an increase of the amount of factor H fixed at the bacterial surface. The YadA monomer separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to a nitrocellulose membrane was able to bind factor H. We conclude that factor H bound to YadA reduces the C3b deposition on the bacterial surface, probably by a rapid inactivation of C3b.

Adhesins, Bacterial↗
PubMed1987

Addison's disease: immunological aspects.

The frequency of HLA DR3 in patients with Addison's disease is increased and the relative risk factor rises to 10 when adrenocortical failure is part of a polyendocrinopathy.

Addison Disease↗
PubMed1985

AIDS in two African children--one with fibrosarcoma of the liver.

We report here on two black African girls who developed an acquired immune deficiency syndrome (AIDS). The first patient was a premature girl born to healthy parents. She suffered from interstitial pneumonitis during the first week of life and died of it at the age of 6 months. Her mother, although asymptomatic, had polyclonal hypergammaglobulinaemia, a reversed T-helper/T-suppressor ratio and a decreased lymphocyte response to mitogens. The second patient had the first symptoms at the age of 6 years, developed a primitive malignant fibrosarcoma of the liver at 8 years old and died 1 year later. AIDS can affect black African children who have not been transfused and whose family members are not considered as at a high risk for this disease. In children, AIDS and cancer can be associated. In the second patient, cytotoxic suppressor lymphocytes (OKT8 positive cells) were shown to behave in vitro as precursors of T-killer cells.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Live varicella vaccine in severely immunodepressed children.

One dose containing 3,100 PFU of a live attenuated Oka-strain varicella vaccine (Varilrix, Smith Kline-RIT, Belgium) was administered subcutaneously to 45 children, 26 of whom were suffering from acute leukaemia and 19 from solid malignant tumours. Their immunological status had been severely compromised by chemotherapy as evidenced by markedly low values for all immunological parameters. Of the 31 children seronegative for varicella at the time of vaccination, 70%, 85%, 75%, and 40% had varicella serum antibodies at 1, 2, 3, and 12 months after vaccination, respectively. Evaluation of the immunological parameters indicated that they were of no predictive value regarding the antibody response of the patients to the vaccine. Eight children (18%) developed varicella after vaccination. In one case, the disease was caused by the vaccine virus while in another, the vaccine virus was probably also responsible. The remaining six cases were caused by wild virus. The antibody response and accompanying protection against disease induced by the vaccine in severely immunodepressed patients is acceptable, but clearly lower and of shorter duration than in normal subjects. Thus, in immunocompromised patients, booster doses of the vaccine may be required at relatively short intervals.

Chickenpox↗
PubMed1984

Acquired immunodeficiency syndrome in African patients.

Between May 1979 and April 1983, 18 previously healthy African patients were hospitalized in Belgium with opportunistic infections (cryptococcosis, Pneumocystis carinii pneumonia, central-nervous-system toxoplasmosis, progressive cutaneous herpes simplex virus infection, disseminated cytomegalovirus infection, candidiasis, or cryptosporidiosis) or Kaposi's sarcoma, or with both. Ten of them died. During the same period five other patients were hospitalized with an illness consistent with a prodrome of the acquired immunodeficiency syndrome (chronic lymphadenopathy, fever, weight loss, and diarrhea). All patients tested had a marked decrease in helper T cells; an inversion of the normal ratio of helper to suppressor T cells, and a decreased or absent blastogenic response of lymphocytes to mitogens. Twenty patients had anergy. There was no evidence of an underlying immunosuppressive disease and no history of blood-product transfusion, homosexuality, or intravenous-drug abuse. This syndrome in patients originating in Central Africa is similar to the acquired immunodeficiency syndrome reported in American patients.

Acquired Immunodeficiency Syndrome↗
PubMed1979

[Segregation of HLA haplotypes in a family with infants having spina bifida].

The search for HLA association in spina bifida is particularly interesting since this condition can be associated with the effect of the T locus in mice. Gene and haplotype frequencies in 32 unrelated patients suffering from spina bifida were studied. Patients and families were examined clinically and radiologically. A high frequency of spina bifida occulta and other vertebral abnormalities was found suggesting genetic determinism but no evidence of linkage with HLA genes or haplotypes was found.

Adolescent↗
PubMed1977

HLA gene and haplotype frequencies in spina bifida. Population and family studies.

The search for HLA association in spina bifida is particularly interesting since this condition can be associated with the effects of the T locus in mice. Gene and haplotype frequencies in 32 unrelated patients suffering from spina bifida were studied. Gene frequency of HLA-B5 and haplotype frequency of A2, B5 were increased without reaching signification levels. Fourteen families were examined clinically and radiologically. A high frequency of spina bifida occulta and other vertebral abnormalities was found without evidence of linkage with HLA haplotypes.

Adolescent↗