Familial deficiency of immunoglobulin IgA2.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E J Bast.
Explore the source record for details and available documents.
A reverse T cell plaque assay was employed to study the ability of purified T cells isolated from the blood of seven patients with B cell chronic lymphocytic leukaemia (B-CLL) to secrete antigen-specific helper or suppressor factors (ThF and TsF respectively) after activation in vitro. It was found that in spite of the phenotypical presence of CD8+ cells, the frequency of TsF-secreting cells was strongly decreased as compared to normal values. T cells secreting ThF could be generated in all B-CLL patients tested in about normal frequencies. These results may indicate a tumour induced change in the distribution of cellular subsets within the CD8+ cell compartment.
Two cases of transient biclonal gammopathy are described, one having an IgG kappa and an IgA kappa monoclonal component and another with IgG1 kappa and IgG4 kappa monoclonal components. In both of these cases the second monoclonal component gradually disappeared. Anti-idiotypic antibodies were made against the major monoclonal serum component; in the first case the idiotype of the IgG kappa clone was not found in the IgA kappa plasma cells (real biclonal gammopathy) whereas in the second case the idiotypes of the two clones were identical (apparent biclonal gammopathy). The evolution to monoclonal gammopathy is discussed with regard to the existence of common malignant precursor cells in biclonal gammopathy.
This study provides evidence that leukaemic B cells are able to proliferate and differentiate into plasmablasts. The Ig produced was monoclonal in nature and this was shown by gel electrophoresis.
In a group of 176 apparently healthy aged people living at home (age range 62-86 years) the prevalences of monoclonal immunoglobulin and of autoantibodies did not differ from those found in other studies, but remarkably 38% of the people studied had cold lymphocytotoxic antibodies. The occurrence of serological abnormalities showed no age dependency. The participants were grouped according to serological abnormalities. The various groups showed no differences in peripheral blood mononuclear cell composition (concentration of B lymphocytes and T lymphocytes or of T lymphocyte subsets with OKT 4 and OKT 8 phenotype) or function (lymphocyte stimulation with phytohaemagglutinin, concanavalin A, pokeweed mitogen and antigen cocktail). Compared with a control group of young blood donors, the lymphocyte stimulation responses tended to be lower in the old age groups. It is concluded that, as measured in this study, humoral abnormalities during ageing are not associated with changes in B and T lymphocyte subsets or function.
A case of familial selective IgA2 deficiency is described. The mother had no detectable IgA2, but a low level of IgA1. She had anti-alpha 2 antibodies of the IgG class. One of her daughters also lacked IgA2 with a normal level of IgA1. The analysis of the immunoglobulin haplotypes of the family suggested the deletion of the alpha 2-gene. In addition, the analysis of B lymphocytes of mother and daughter showed the absence of IgA2-bearing cells. Upon stimulation with pokeweed mitogen, the B cells differentiated into IgA1-containing plasma cells, but IgA2-containing cells were not found. The results suggest a defect in the generation of intraclonal B cell isotype diversity. The molecular basis of this phenomenon is unknown.
Explore the source record for details and available documents.
Peripheral blood lymphocytes (PBL) from 14 patients with chronic lymphocytic leukaemia (CLL) were stimulated with pokeweed mitogen (PWM), formalinized Staphylococcus aureus (Sta) and a combination of both mitogens. The leukaemic B cells were characterized by rosetting techniques (using mouse erythrocytes and complement coated erythrocytes) and immunofluorescence for membrane bound immunoglobulin (mIg). No clear correlation between phenotype and the reactivity with PWM could be found. Results of stimulation with Sta however, indicate that lymphocytes carrying membrane bound IgM (mIgM) and IgD (mIgD) and the receptor of the third complement component (C3R) can be induced to differentiate into immunoglobulin (Ig) containing cells. Addition of PWM to these cultures often enhanced this response. Some leukaemic B cells are able to differentiate after challenge with the appropriate stimulus.
Malignant monoclonal gammopathy (MMG) cannot easily be distinguished from the benign (BMG) form in a number of cases. Using two different anti-J chain reagents it could be shown in the present study that in MMG, J chain is present in most of the IgG-containing plasma cells in the bone marrow. In BMG, the frequency of J chain-containing IgG plasma cells is low and not different from that obtained in healthy individuals. Essentially similar findings regarding idiotype were obtained, using anti-idiotype conjugates, specific for the patients' monoclonal immunoglobulins. In one patient malignancy was indicated by the presence of a high percentage of J chain-containing IgG plasma cells in the bone marrow, prior to clinical expression of multiple myeloma.
Rabbits were hyperimmunized with Micrococcus Pysodeicticus, leading to homogeneous antibody responses. Peripheral blood lymphocytes were taken from the rabbits before and monthly (during 3 months) after the start of the immunization. The cells were stored frozen. Lymphocytes were tested with anti-idiotypic conjugates for the presence of surface idiotypic structures. The nature of the idiotype-positive cells was determined with respect to the presence of IgM or T-cell antigenic determinants on their surface. A sharp rise and fall in the percentage of idiotypic lymphocytes was found, ranging between 1/40,000 and 1/1,000. Initially almost all idiotypic lymphocytes were IgM-positive. In the blood taken 2 months after the start of the immunization 20% of the idiotypic cells belonged to the T-cell population and 10% were negative for both IgM and T-cell antigenic determinants.