Marc De Bruyère

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.

Intracellular cytokine profile of cord and adult blood monocytes.

Cord blood (CB) transplantations are associated with low graft-versus-host disease (GVHD). The pathophysiology of GVHD involves interaction and activation of different cell types, as lymphocytes and monocytes, and results in a cascade of cytokine production. After antigen or mitogen stimulation, CB monocytes release lower levels of cytokines than adult blood (AB) monocytes. In this study, the detection of intracellular IL-1β and TNF-α produced by monocytes was evaluated in response to tuberculin PPD to investigate whether the reduced capacity of CB monocytes to secrete cytokines could be related to an impaired functional activity and to a particular phenotypic profile. Results showed that the percentage of CD64+monocytes producing intracellular IL-1β and TNF-α was significantly lower in CB and that the phenotypic profile of CB monocytes producing these cytokine (CD64+CD14+) was different to that of AB monocytes (CD64+CD14+, CD64+CD33+ and CD64+ CD45RO+). These results suggest that the lower capacity of CB monocyte populations to produce IL-1β and TNF-α might be due to a functional immaturity of CB monocytes at the cellular level as reflected by the different phenotypic profile of CB monocytes. Bone Marrow Transplantation (2001) 27, 1081–1086.

HLA haplotypes and long survival in childhood acute lymphoblastic leukaemia treated with transfer factor.

Association between HLA haplotypes and a long survival was investigated in 116 children with acute lymphoblastic leukaemia. It was found that patients with A2 B12 and/or A2 B40 haplotypes survived longer than patients without these two haplotypes. Since all children were treated with transfer factor obtained from their relatives, it is suggested that children possessing A2 B12 or A2 B40 haplotypes may respond better to this type of immunotherapy.

Early AIDS cases originating from Zaïre and Burundi (1962-1976).

Three retrospectively diagnosed fatal AIDS cases are reported and discussed together with 4 other HIV seropositive patients, who all apparently contracted the HIV infection prior to the beginning of the present outbreak, without any other risk factor than heterosexual exposure in Central Africa. These data and simultaneous information from other sources contribute to the assumption that AIDS is an old disease in Central Africa. AIDS, having presented itself as a sporadic and ill defined entity, remained unrecognized in Central Africa until the outset of the present outbreak.

Utility of xenografts: Lack of correlation between PRA and natural antibodies to swine

Abstract: Among the patients that might potentially benefit from the availability of xenografts are those in kidney failure who demonstrate high levels of antibody reactivity to panels of typing lymphocytes. Such individuals with high PRA (panel reactive antibody) are unlikely to receive a renal allograft because they are highly sensitized to the vast majority of potential donors. In addition, all humans have demonstrable levels of natural antibodies reactive to distantly related species such as the pig. If there were a correlation between PRA and levels of natural antibodies, then such patients would also be at greater risk for hyperacute rejection of xenografts. We have therefore examined, in a blinded fashion, the porcine lymphocyte reactivity of sera from PRA positive donors. Subsets of the 105 sera tested were grouped by PRA level and analyzed for levels of natural antibodies detectable by a complement‐dependent cytotoxicity assay on porcine lymphocytes. There was no significant difference in the range of titers of natural antibodies between subsets. Thus, there was no demonstrable correlation between levels of PRA and levels of natural antibodies to porcine lymphocytes.

Reliable and very sensitive flow-cytometric method for counting low leucocyte numbers in platelet concentrates.

Reduction of leucocytes in blood components, achieved by filtration, may reduce the risk of HLA alloimmunization, virus transmission, and febrile reactions. Nevertheless, white blood cell (WBC) concentrations obtained in this way can be too low to be accurately counted with automated and manual techniques. We describe here a rapid, reliable, and very sensitive method for counting low leucocyte numbers using flow cytometry. WBC nuclei are labelled by propidium iodide. A known amount of fluorescein‐ and phycoerythrin‐conjugated beads (Standard Brite, Coulter) is added as an indicator of the examined volume. The time required for analyzing one tube is approximately 5 min. This method was first validated by comparing WBC counts (120–2,570/μl) assessed on a haemocytometer (Bürker) and by flow cytometry. The second step was to determine the sensitivity of the method: we diluted normal platelet concentrates with phosphate‐buffered saline. The comparison of expected with observed values showed a very good correlation up to a concentration of 1 WBC/μl. This technique is an accurate method that can be applied in blood bank quality controls and in clinical studies.

Transplantation of umbilical cord blood in a refractory lymphoma.

A successful cord blood transplantation combined with hematopoietic growth factor was performed in a boy presenting with refractory mediastinal T-cell lymphoma. Cord blood cells were collected from an HLA-identical sibling at the time of delivery. A transient and corticosensitive acute grade II graft versus host disease was observed. One year after transplantation, the child is still in remission with complete engraftment. This is the first report of cord blood transplantation in a patient with refractory lymphoma.

Membrane marker studies with anti-T, anti-Ia (DR) and anti-myeloblast antisera in acute leukaemias

Abstract Hetero-antisera reacting specifically with all cells of the T lineage, with Ia-like (DR) antigens or with myeloblasts were used as diagnostic aids in the classification of 64 acute leukaemias. The anti-myeloblast proved particularly useful in discriminating early myeloblasts from atypical lymphoblasts and undifferentiated blasts.

Anti-hepatitis C virus positivity (HCV) in Belgian volunteer blood donors: source of contamination and HCV-testing among donors and related recipients.

We investigated a group of Belgian HCV-100 Elisa positive volunteer blood donors for potential sources of contamination and the presence of liver biochemical abnormalities. In addition, results of serological testing and liver biochemistry of their related blood products recipients were also analysed. In blood donors, anti-HCV-100 repeat reactive rate was 0.77% with a 34% rate of abnormal liver function tests. A potential source of parenteral exposure was found in all donors with RIBA-confirmed HCV-100 positivity. Among recipients, anti-HCV-100 RIBA-2 positive blood product donations were associated with RIBA-2 seroconversion, a history of transfusion in donors being of high predictive value of infectivity.