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B Van Camp

Publications and source records attributed to B Van Camp.

At least 19 recordsLinked to original sources
PubMed1992

Evidence that multiple myeloma Ig heavy chain VDJ genes contain somatic mutations but show no intraclonal variation.

To investigate whether somatic hypermutation occurs in multiple myeloma (MM) Ig VH region genes, we have cloned and sequenced the expressed VH genes from five cases of MM. The sequences were obtained after polymerase chain reaction (PCR) on total RNA isolated from the bone marrow, using 5' VH family-specific leader and 3' C gamma- or C alpha-specific primers. MM-specific CDR3 oligonucleotides were produced to isolate VH genes expressed by the malignant plasma cells. In all five cases, the productive Ig gene used the VH3 family. Extensive sequence analysis of multiple independent M13 clones showed no intraclonal variation with no evidence for ongoing somatic hypermutation in MM VH region genes. We were able to identify possible germline counterparts of the expressed VH genes in two cases. Comparison of these genes shows that the MM VH region genes have somatic mutations characteristic for an antigen-driven process. In the other three cases, no close homology could be found with published VH3 sequences. These findings implicate that, in MM, clonal proliferation takes place in a cell type that has already passed through the phase of somatic hypermutation.

Adult↗
PubMed1992

Large granular lymphocyte proliferative disease: 21 Belgian cases and review of the literature.

We report the findings in 21 Belgian patients (12 males and 9 females, median age 61 years) with LGLPD. Symptoms at presentation included infection (n = 9), weight loss (n = 5), asthenia (n = 9), pruritus (n = 2) and arthralgia (n = 7). Four patients were asymptomatic. The main clinical findings were hepatomegaly (n = 5), splenomegaly (n = 8), lymph node enlargement (n = 3) and arthritis (n = 5). All patients had an increased LGL count associated with anemia (n = 12), neutropenia (n = 17), often less than 0.5.10(9)/L (n = 10) and thrombocytopenia (n = 6). Three patterns of lymphocyte surface markers were observed: CD3+CD4-8+ (14 patients), CD3+CD4-8+ (5 patients) and CD3+CD4+8- (1 patient). An abnormal karyotype was found in 2 patients. T-cell receptor gene was rearranged in all cases tested (9/9).

Adult↗
PubMed1992

Chemotherapy-induced acral erythema and acute graft-versus-host disease after allogeneic bone marrow transplantation.

Chemotherapy-induced acral erythema is a rare disorder characterized by a painful and intense erythema of the palms and the soles. In allogeneic bone marrow transplant patients, the differential diagnosis of acute graft-versus-host disease (AGVHD) may be difficult. We describe a case of concurrent acral erythema and AGVHD. The clinical features of both conditions as well as the histological findings on serial skin biopsy specimens are discussed.

Acute Disease↗
PubMed1991

Leukemia and lymphoma immunophenotyping in cell smears with immunogold-silver staining.

The potential of the immunogold-silver staining (IGSS) technique for immunophenotyping leukemia and lymphoma cells in cell smears was examined. Peripheral blood, bone marrow aspirates, lymph node biopsy specimens, fine-needle aspirates, and biologic fluids of 83 patients with acute or chronic leukemias, non-Hodgkin's lymphomas, or Hodgkin's disease were labeled. Cell smears, cytocentrifuge preparations, or imprints were fixed, incubated with the reagents, and counterstained with May-Grünwald-Giemsa. Stable immunostaining and good morphologic characteristics allowed accurate cell identification and rapid enumeration of the positive cells. The immunophenotypes obtained with the use of 35 monoclonal antibodies with different specificities were similar to those determined by flow cytometry or immunohistochemical studies on the same samples. This IGSS method was especially useful for the examination of poor samples or complex cell suspensions with rare malignant cells. It could be an alternative to the immunoenzyme methods that generally are used for this purpose.

Antibodies, Monoclonal↗
PubMed1991

Expression of cytoadhesion molecules (CD56, CD54, CD18 and CD29) by myeloma plasma cells.

Recently we reported the expression of the human natural killer cell associated antigen CD56 (Leu 19/NKH1) in plasma cells of a majority of multiple myeloma (MM) patients. CD56 is known to be an isoform of the human neural adhesion molecule N-CAM which is involved in homotypic adhesive interactions. By immunophenotyping using four CD56 specific monoclonal antibodies and immunoprecipitation analysis we here confirm that the Leu 19 antigen expressed by myeloma plasma cells is identical to N-CAM and corresponds to the 145 kDa isoform. Because of the possible biological role of adhesion molecules on myeloma cells, we compared the expression of N-CAM with the intercellular adhesion molecule 1 (ICAM-1) and the beta 1 and beta 2 integrins. By immunogold-silver staining of cytospin preparations of mononuclear cell suspensions, bone marrow plasma cells of 17 MM patients were analysed. Plasma cells expressed N-CAM (CD56) in 14 patients. ICAM-1 (CD54) in 16 patients, and beta 2 integrins (CD18) in eight patients. beta 1 integrins (CD29) were expressed in all patients. The expression of beta 2 integrins was always very weak while N-CAM, ICAM-1 and the beta 1 integrins showed a moderate to strong positivity. The plasma cells of five haematological normal individuals lacked significant N-CAM expression but were positive for ICAM-1 and both integrin subgroups. One plasma cell leukaemia patient and two out of four end-stage MM patients showed no expression of N-CAM or beta 2 integrins on their circulating plasma cells. Among 11 previously established myeloma cell lines, surface expression of ICAM-1 and the integrins was detected in most cases, while N-CAM was present in only four lines. Most cell lines showed coexpression of the fibronectin receptors (VLA-4 and VLA-5) and the laminin receptor (VLA-6). The collagen receptor (VLA-2) was not expressed. The N-CAM negative cell lines included four cell lines that were derived from plasma cell leukaemia patients. These results indicate that the expression of adhesion molecules is an intrinsic part of the biology of multiple myeloma.

Antigens, CD↗
PubMed1990

Plasma cells in multiple myeloma express a natural killer cell-associated antigen: CD56 (NKH-1; Leu-19).

Bone marrow samples from 55 patients with multiple myeloma (MM) and 23 patients with monoclonal gammopathy of undertermined significance (MGUS) were evaluated with a broad panel of monoclonal antibodies. Plasma cells from 78% (43/55) of patients with MM strongly expressed the natural killer cell antigen CD56 (NKH-1, Leu-19). Of the 23 patients with MGUS, none showed strong CD56 reactivity, although three had weak reactivity in less than 20% of plasma cells. Myeloma cells expressing CD56 did not coexpress the CD57 or CD16 antigens. Patients with CD56-positive plasma cells had both indolent and aggressive disease. However, the 12 CD56-negative patients had predominantly aggressive disease with an unexpected preponderance of kappa Bence Jones only myeloma (5/10[50%] evaluable patients). Polyclonal plasma cells from non-neoplastic tissue sites (normal bone marrows, lymph nodes, tonsillar biopsies, and gut-mucosa biopsies) showed a near absence of CD56. We conclude that isolated, strong CD56 expression is common in MM, but not in MGUS or reactive plasma cells. The potential biologic importance of CD56 positivity in myeloma is reviewed.

ADP-ribosyl Cyclase↗
PubMed1990

Immunomagnetic purging of bone marrow grafts for autologous transplantation in neuroblastoma.

Bone marrow grafts of 5 patients with stage IV neuroblastoma and one patient with stage IV retinoblastoma were harvested during complete remission and in vitro processed for autologous transplantation. Because of the risk to reinfuse metastatic cells, the grafts were immunomagnetically purged. After preparation of the buffy coat fraction, mononuclear cells (mnc) and progenitor cells (CFU-GM) were enriched by density centrifugation and incubated successively with a cocktail of five tumour reacting monoclonal antibodies and magnetic microparticles. Target cells were removed by a set of samarium cobalt magnets. The purged grafts were stored in liquid nitrogen. After the complete procedure, an average of 16% nucleated cells of the initial harvest could be recovered. This corresponds with a mean number of 0.5 X 10(8) mnc and 2.4 X 10(4) CFU-GM per kg body weight being available for grafting. So far, 5 patients received their purged marrow graft and showed a sustained take.

Bone Marrow Cells↗
PubMed1990

Malignant lymphoma of the bone.

Two cases of bone involvement by a malignant lymphoma are described. The first patient suffered from primary, polyostotic non-Hodgkin's lymphoma of lymphoblastic histology, a rare clinical picture according to literature data. The second patient had mediastinal Hodgkin's lymphoma of the nodular sclerosing type with a unique secondary localization in the femoral bone, that led to the final diagnosis. The diagnostic and therapeutical approach of bone lymphoma is discussed.

Adolescent↗
PubMed1990

Isotype switch and idiotype variation in hairy cell leukemia.

Hairy cell leukemia (HCL) cells are B lymphocytes expressing monoclonal surface bound immunoglobulins, B cell specific antigens, and activation markers. Based on immunophenotyping analysis, HCL cells have been reported to express simultaneously multiple Ig heavy chain isotypes. This is in contrast with the majority of other B cell malignancies. To analyse the tumor cell Ig in more detail, we have prepared somatic cell hybridomas from two patients with HCL. In both cases we found that the tumor cell derived hybridomas secreted IgM, IgG, or IgA indicating that a class-switch event does occur within the monoclonal tumor cell population. However these hybridomas expressed only single isotypes. The clonal relatedness of the tumor-derived Ig was shown by Ig gene analysis and by reactivity with a panel of idiotype specific antibodies. The tumor Ig of one patient analysed showed a striking variability in idiotope expression, indicative of somatic mutations of the expressed Ig genes. To our knowledge this is the first example of HCL and of a B cell malignancy other than follicular lymphoma for which somatic mutations have been demonstrated. This finding might be important for the therapeutic approach based on monoclonal anti-idiotype antibodies.

Antibodies, Anti-Idiotypic↗
PubMed1989

Detection of monoclonal B lymphocytes in bone marrow and peripheral blood of multiple myeloma patients by immunoglobulin gene rearrangement studies.

To investigate whether B lymphocytes are involved in the malignant cell clone of multiple myeloma (MM), we performed immunoglobulin gene rearrangement analysis of mononuclear cells and separated B lymphocytes, isolated from bone marrow and peripheral blood of MM patients. The B lymphocytes were separated by immunomagnetic beads, coated with an HLA class II specific antibody. Southern blot analysis with a JH probe revealed in the bone marrow of three out of seven patients identical immunoglobulin gene rearrangements in the B lymphocytes when compared to the plasma cells. Out of 10 patients, two patients with a high tumour burden were found to have monoclonal B lymphocytes in the peripheral blood. These results suggest that B lymphocytes in the bone marrow are part of the myeloma clone and that they can circulate in the peripheral blood. Although previous studies indicated that the ratio of K to lambda bearing lymphocytes in the peripheral blood can provide evidence for B cell monoclonality, we did not find a correlation between the results of K/lambda analysis and immunoglobulin gene rearrangement.

Antibodies, Monoclonal↗
PubMed1989

An immunogold-silver staining method for detection of cell surface antigens in cell smears.

We developed an indirect immunogold-silver staining method for detection of leukocyte cell surface antigens in cell smears. Air-dried and fixed cytocentrifuge preparations or smears of peripheral blood leukocytes were incubated with monoclonal antibodies (MAb) and colloidal gold-labeled secondary antibodies. The preparations were post-fixed and silver enhancement was performed. The smears were counterstained with May-Grunwald-Giemsa and examined in brightfield light microscopy. The morphology of the cells was well preserved. Leukocytes reacting with the MAb showed black granules on their surface membranes. The intense immunostaining and the low background allowed a rapid enumeration of the positive cells. The labeling could be detected with high sensitivity by epipolarization microscopy. This immunogold-silver staining method was used to quantify T- and B-lymphocytes and natural killer cells in buffy coat smears of normal adult blood. These lymphocyte subsets correlated well with those obtained in smears with the alkaline phosphatase-anti-alkaline phosphatase (APAAP) method and with those found by labeling of mononuclear cells in suspension with immunogold-silver staining. This immunogold-silver staining method forms a good alternative to immunoenzyme methods for study of hematologic cells. In addition, it could be a general procedure for detection of cell surface antigens in all kinds of cell smears.

Antibodies, Monoclonal↗
PubMed1988

Hematologic values and lymphocyte subsets in fetal blood.

Hematologic values and lymphocyte subpopulations were determined in normal fetal blood during the second trimester of gestation. In these samples the platelet, erythrocyte, and leukocyte counts were significantly lower than in adults. Large red blood cells with a high hemoglobin content were present. Before the twentieth week of gestation, erythroblasts made up about half of the nucleated elements. Lymphocytes formed most of the leukocytes, and their absolute numbers were comparable to those in adults. Most of the fetal blood lymphocytes expressed T- or B-cell surface differentiation antigens. The percentage of T-cells was lower and that of B-cells was higher than in the adult. A high OKT4/OKT8 ratio was present. It was due to a low percentage of OKT8-positive cells. Lymphocytes with a natural killer cell phenotype were rare. Most lymphocytes were OKT10 positive, but almost none reacted with the antithymocyte antibody OKT6. These results give additional information about the development of blood cells in early human life. They can be used as reference values for the prenatal diagnosis of hereditary or acquired anomalies of the hematologic and immunologic systems.

Fetal Blood↗
PubMed1988

Sensitive detection of immunogold-silver staining with darkfield and epi-polarization microscopy.

We evaluated the contribution of darkfield and epi-polarization microscopy to the detection of leukocyte cell surface antigens with immunogold-silver staining (IGSS). Lymphocyte cell surface differentiation antigens were labeled with monoclonal antibodies and IGSS as described for brightfield microscopy. In darkfield and epi-polarization microscopy the labeling appeared as bright spots on a dark background. The sensitivity of detection was much higher than that of brightfield microscopy. Sixteenfold higher dilutions of the monoclonal antibody could be used to detect all cells expressing the antigen in the cell suspension. However, non-specific staining was also better visualized. The latter could be reduced to a level comparable to that of brightfield microscopy only by use of weaker labeling conditions. A 25% reduction of the silver enhancement time was necessary for this purpose. However, these weaker labeling conditions also reduced the intensity of the specific staining. Therefore, the efficiency of IGSS, as detected with darkfield and epi-polarization microscopy, was only fourfold greater than that found with brightfield microscopy or that of an immunofluorescence procedure. Especially in combination with transmitted light, to improve cell identification, epi-polarization microscopy is a reliable and sensitive method for detection of immunogold-silver-labeled cell surface antigens for diagnostic and research purposes.

Antibodies, Monoclonal↗
PubMed1986

Detection of cell surface antigens in cryostat sections with immunogold-silver staining.

Immunogold-silver staining was used for the detection of lymphocyte cell surface antigens in cryostat sections of lymphoid tissues. The sections were incubated with monoclonal mouse antibodies and then with colloidal gold-labeled goat anti-mouse antibodies. They were then immersed in a physical developer, counterstained, and mounted. In light microscopy, the tissue architecture was well preserved, and a dark labeling was seen on the positive cells. Optimal labeling conditions were determined. The distribution of the lymphocyte subsets, as defined by a panel of monoclonal antibodies in tonsil and reactive lymph nodes, was similar to that found with a biotin-avidin-horseradish peroxidase method. The monoclonality of the neoplastic cells in lymph nodes of B-cell non-Hodgkin's lymphomas clearly could be demonstrated. The sensitivity of the technic was comparable with that of the biotin-avidin-horseradish peroxidase labeling method. In addition, immunogold-silver labeling was combined with acid phosphatase cytochemistry.

Antibodies, Monoclonal↗
PubMed1986

Immunogold-silver staining of lymphocyte surface antigens on cells in suspension and in lymph node cryostat sections.

An immunogold-silver staining (IGSS) technique for the light microscopical detection of leucocyte cell surface antigens in cell suspensions and cryostat sections is described. The specimens were first incubated with monoclonal mouse antibodies and then with colloidal gold-labelled goat anti-mouse antibodies. They were then immersed in a physical developer, counterstained and mounted. In light microscopy, the tissue architecture and the cellular morphology were well preserved. Positive cells showed dark granules on their surface membranes. Optimal labelling conditions were determined. This method proved to be a reliable tool for the enumeration of T-cells and their subsets in peripheral blood. The dense labelling permitted the use of panoptic counterstains like May-Grünwald-Giemsa or Wright's stain. This IGSS technique was used to determine the distribution of the T- and B-cell subsets in cryostat sections of reactive lymph nodes. The sensitivity of the method was comparable with that of immunofluorescence microscopy for cell suspensions and that of the biotin-avidin-peroxidase technique for tissue sections. Immunogold-silver staining was combined with enzyme cytochemistry. In dark-field or epipolarization microscopy the labelling appeared as bright granules on a dark background. With its dense granular membrane labelling and its good morphology IGSS is an ideal method for the study of particular cell types in mixed cell suspensions. In addition, it could be a general method for the detection of cell surface antigens in all kinds of cells and tissues.

Antigens, Surface↗
PubMed1986

An immunogold-silver staining method for detection of cell-surface antigens in light microscopy.

An immunogold-silver staining technique for detection of cell-surface antigens in cell suspensions was developed. Leukocyte cell suspensions were first incubated with monoclonal antibodies directed against cell-surface antigens and then with colloidal gold-labeled goat anti-mouse antibodies. Cytocentrifuge preparations of the cell suspensions were immersed in a physical developer containing silver lactate and hydroquinone as reducing substance. The preparations were then counterstained and mounted. In light microscopy, cells reacting with the monoclonal antibodies showed dark granules on their surface membrane. An optimal morphology, as revealed by a May-Grünwald-Giemsa counterstain, permitted accurate cell identification. The labeling was influenced by the gold particle diameter and the concentration of the gold reagents, by the duration of incubation in the physical developer, and by the composition and temperature of this medium. The T-cell subsets enumerated with this method in the peripheral blood of normal adults were identical to those found with other methods. The sensitivity of the technique was comparable with that of immunofluorescence microscopy. This immunogold-silver staining procedure proved to be a reliable tool for detection of cell-surface antigens in light microscopy.

Antibodies, Monoclonal↗
PubMed1986

Aleukemic leukemia cutis. An unusual presentation of acute myelomonocytic leukemia.

A patient with acute myelomonocytic leukemia is reported. He had presented erythroderma and atypical cellular infiltration of the skin 4 months prior to the detection of leukemia in the peripheral blood and bone marrow. Aleukemic leukemia cutis is a rare condition which is characterized by leukemic cells invading the skin prior to the observation of leukemic cells in the peripheral blood. The cases of aleukemic leukemia cutis reported in the literature show little or no conformity in their clinical appearance. Enzyme cytochemistry, immunocytological and electron-microscopic studies are of considerable help in differentiating the cutaneous infiltrates and in establishing early diagnosis. We report herein a patient with erythroderma which regressed spontaneously, whereas microscopic examination of a cutaneous biopsy showed atypical cells infiltrating the dermis. After a period of 3 months, during which the patient remained free of lesions, he showed recurrence of the erythroderma while developing acute myelomonocytic leukemia. We feel this unusual presentation of aleukemic leukemia cutis should be added to the evergrowing list of cutaneous manifestations of leukemia.

Dermatitis, Exfoliative↗