Low titre autoantibodies against recoverin in sera of patients with small cell lung cancer but without a loss of vision.

To date, many authors have described the presence of autoantibodies against various neuronal proteins, paraneoplastic antigens (PNA), in a serum of patients with different kinds of malignant tumors located outside the nervous system. These autoantibodies may cross-react with the corresponding PNA or their epitopes present in neurons and thus initiate the development of a variety of neurological disorders, paraneoplastic syndromes (PNS), even though the primary tumor and its metastases have not invaded the nervous system. Cancer-associated retinopathy (CAR) is a rare ocular PNS induced by autoantibodies against several retinal antigens, one of which is a photoreceptor calcium-binding protein, recoverin. Only several CAR patients with a few kinds of cancer (endothelial carcinoma, breast cancer, epithelial ovarian carcinoma) have so far been found to contain autoantibodies against recoverin in their sera. As for lung cancer, the majority of CAR cases mediated by anti-recoverin autoantibodies have been revealed in patients with the most malignant lung cancer, small cell lung carcinoma (SCLC), and only one similar case has been described for a patient with non-small lung carcinoma. The common feature of all these anti-recoverin-positive patients, irrespective of the type of cancer, is the presence of both the CAR syndrome and high titres (as a rule, more than 1:1000) of the underlying autoantibodies in their serum. In this study, we have used recombinant myristoylated recoverin to screen serum samples of 50 patients with SCLC by Western blot and revealed 5 individuals with low titres of anti-recoverin antibodies, who have no manifestation of a loss of vision. To our knowledge, this is the first report on the presence of low titre autoantibodies against recoverin in a serum of patients with cancer, but without visual dysfunction.

[Use of monoclonal antibodies for immunodiagnosis of lung cancer]. / Ispl'zovanie monoklonal'nykh antitel dlia immunodiagnostiki raka legkikh.

Fifty-three patients with lung cancer of different histological types and 72 with other lung diseases were examined by employing the panel containing 5 monoclonal antibodies (MAb) in the indirect immunofluorescence test (IFT). with tissue biopsy specimens, lung cancer could be revealed in 100% of patients with glandular carcinomas and adenocarcinoma of the lung, in 89% of those with small-cell carcinoma, and in 61% with squamous-cell carcinoma. With this, MAb reacted with cancer cellular membranes, by causing their fluorescence and failed to react and to cause the luminescence of inflammation cell membranes, the altered and intact bronchoalveolar epithelium in patients cancer and nontumoral diseases of the lung. IFT with MAb to lung cancerous surface antigens with the cells of tissue biopsy specimens may be a supplementation to cytological studies.

[The effect of cells presenting the erythroblast antigen on the natural suppressor activity of nonadhesive bone marrow cells]. / Vliianie kletok, nesushchikh antigen eritroblastov, na estestvennuiu supressornuiu aktivnost' neadgezivnykh kletok kostnogo mozga.

Concanavalin A-induced proliferation of spleen cells of C57B1/6 mice was inhibited by syngeneic normal bone marrow cells. Elimination of Ag-Eb-positive cells by panning was shown to result in markedly reduced inhibitory activity of bone marrow cells. To evaluate the role of Ag-Eb in natural suppressor activity, bone marrow cells were preincubated with different dilutions of MAE-15 monoclonal antibody and then added to spleen cells. The inhibitory effect of bone marrow cells decreased with the increasing concentration of the monoclonal antibody in a dose-dependent manner and nearly disappeared at a concentration of MAE-15 of 150 m micrograms/ml and 300 m micrograms/ml. In control experiments, bone marrow cells were preincubated with antibodies non-reactive with Ag-Eb under the same conditions. It is concluded that the decrease of natural suppressor activity after incubation of bone marrow cells with MAE-15 monoclonal antibody is specific for anti-Ag-Eb antibodies.

[Monoclonal antibodies to human small-cell lung cancer]. / Monoklonal'nye antitela k melkokletochnomu raku legkogo cheloveka.

Murine monoclonal antibodies to human small cell lung cancer (SCLC) have been developed and partially characterized. Primary hybridoma clones were screened in the indirect immunofluorescence assay (IFA) on alive H417 cells. Then five clones (IgG1, IgG2a, IgG3 and IgM) non-reactive with normal human bone marrow cells and positively reactive with SCLC tumors were selected. The H417.3 antibody is directed against 47-50kD surface antigens of H417 cells. The antibodies are supposed to be applied for the immunodetection of SCLC metastases to bone marrow and immunotoxin preparations.