Bone marrow and peripheral blood natural killer cell activity in lymphomas. Its response to IL-2

Natural killer (NK) cytotoxic activity was simultaneously investigated in bone marrow mononuclear cells (BMMC) and peripheral blood lymphocytes (PBL) from nine Hodgkin's disease (HD) and 15 non-Hodgkin lymphoma (NHL) untreated patients. Twenty-five PBL samples and seven bone marrow specimens from healthy individuals were also included as control group (C). NK cell activity was evaluated in basal condition and post-stimulation with human recombinant IL-2 (rIL-2). Data were expressed in K values (number of BMMC or PBL needed to lyse 50% of the target cells). In basal condition, both HD and NHL patients showed a NK cell activity comparable to the C group, both in BMMC (HD, K = 2.48 +/- 1.3; NHL, K = 3.8 +/- 2.0; C, K = 3.2 +/- 0.7) and PBL (HD, K = 2.0 +/- 1.0; NHL, K = 2.3 +/- 1.0; C, K = 2.2 +/- 0.2). Stimulation with rIL-2 induced a significant and comparable enhancement of the NK activity in PBL from HD, NHL and C while the response to rIL-2 of the BMMC in most of the HD and NHL patients was significantly greater than the C group. Responder cells were characterized by negative selection with specific MoAb plus complement as a CD3-, CD16+, CD56+ cytotoxic cell and further confirmed by flow cytometry. We postulate that IL-2 activation of bone marrow NK cell precursors, in addition to enhancing the activity of circulating NK, may be of value for the therapeutic rationale of IL-2 in patients with lymphoma.

[Hepatitis C in Venezuela. Preliminary report]

Five hundred serum samples from volunteers blood donors were investigated in order to determine the presence of anti-HCV antibodies by an enzyme-linked immunoassay recently developed worldwide. Prevalence of true-positive samples was 1.2% (6/500), 2 fold higher than the reported prevalence in most of the industrialized countries. From these 6 sera, one (16.6%) showed simultaneous reactivity for HBV anticore antibody. Three sera (25%) from 12 patients with diagnosis of Non-A Non-B hepatitis were reactive for anti-HCV antibodies while in a group of 32 sera with negative HAV and HBV screening, 4 (12.5%) showed anti-HCV antibodies. Two samples out of 16 sera persistently positive for anticore demonstrated the presence of anti-HCV antibodies. The anti-HCV antibodies were undetectable in two cases of autoimmune chronic hepatitis. Our results indicate that in Venezuela, HCV represents a significant problem of public health coexisting in certain cases with HBV infection.

Co-occurrence of albumin complexes with IgE and IgG in the serum of an IgE myeloma patient

The serum of a patient with a clinically and immunologically identified multiple myeloma of the IgE class was found to contain both IgE-albumin and IgG-albumin complexes. These complexes were partially purified and some of their properties studied by biochemical and immunochemical methods. The IgG-albumin interaction was dissociated by 5.0 M guanidine hydrochloride, while the IgE-albumin interaction was dissociated upon reduction by mercaptoethanol, suggesting that the proteins were linked by intermolecular disulfide bonds. Complex formation between pathological or normal immunoglobulins with albumin have been reported for IgG, IgM and IgA but not for IgD or IgE. The present observation seems to be the first in which an IgE myeloma protein was involved.