Quantitative and Qualitative-analysis of Antitetanus Toxoid Antibody-response In the Elderly - Humoral Immune-response Enhancement By Thymostimulin

In order to explore the humoral primary and secondary response to tetanus toxoid (TT), and to define the possible immunopotentiating effect of the thymic hormone thymostimulin, we studied 13 elderly people, selected according to the Senieur Eurage protocol, vaccinated against TT, an antigen never encountered before. Six of them were treated with thymostimulin before and during the immunization protocol. Specific anti-TT antibody level measurement and spectrotypic analysis were performed on the sera collected from the subjects at different times over the immunization protocol. In addition, spontaneous in vitro production of anti-TT antibodies as well as cutaneous delayed hypersensitivity reactions were also studied. Only one patient showed a detectable humoral immune response after the first immunization. After the booster, four of six thymostimulin-treated individuals, compared with only two of seven controls, showed in vivo anti-TT humoral response; at the same time, spontaneous anti- TT production was detected in peripheral blood mononuclear cells from five of six thymostimulin-treated individuals but only three of seven untreated controls. These differences were highly significant (p < 0.0001). In addition, only in thymostimulin-treated subjects were the levels of serum anti- TT antibodies 14, 21 and 28 days after the booster significantly (p < 0.05) higher than the baseline values. The spectrotypic analysis of anti-TT antibodies performed by isoelectric focusing and reverse blotting showed total agreement with the' results from enzyme-linked immunosorbent assay. Cutaneous testing to recall antigens showed that among the thymostimulin-treated subjects four of six converted from negative to positive cutaneous reactions (only one to TT antigen). These four were also responders for anti-TT antibodies. In the control group, only one patient converted from cutaneous negativity to positivity for one antigen other than TT (p < 0.0001). This observation suggests that the immunopotentiating effect of thymostimulin is via the T-helper network. In conclusion, this study demonstrates the adjuvant effect of thymostimulin in the specific T-cell dependent antibody response and emphasizes the necessity to consider a cycle of treatment with immunostimulants in elderly people undergoing specific vaccinations, and the importance of the search for biological adjuvants in the construction of new vaccines

THYMUS REGENERATION INDUCED BY GONADECTOMY IN OLD MICE - CHARACTERIZATION OF T-CELL PHENOTYPE AND MITOTIC RESPONSIVENESS

Gonadectomy performed on male (C57 Bl/10 x DBA/2) F1 and Balb/c mice at the age of 26 weeks induced thymus regeneration. The total number of nucleated cells recovered from the thymus increased in castrated mice up to 8-fold at 2 weeks after surgery and declined almost to the same level as in sham-controls 5 weeks later. Cytofluorimetric analysis of thymocytes from aging mice (1-180 days after birth) or castrated mice (1-49 days after surgery) revealed that all cells recovered from the thymus are Thy 1.2+, distributed in four subpopulations: CD4- CD8- (double negative), CD4+ CD8+ (double positive), CD4+ CD8- and CD4- CD8+ (single positive). Absolute numbers of total cells and cell subsets exhibited similar variations in aging and castrated mice. The percent of each cell subset, except CD4+CD8+, in aging mice was found to oscillate before day 60 but did not significantly change thereafter, while in castrated mice raised to a maximum at day 3, fell to a minimum below the level in sham-controls at day 10 and then increased again to reach the initial values 7 weeks after surgery. The similarity of variations in cell profile suggests that thymus regeneration in old mice involves the same processes as in postnatal development. No significant changes in the proliferative response of thymocytes to Con A were observed at 3, 10, 14, and 35 days after castration, indicating that reconstitution of the thymic mass is not paralleled by recovery of this functional activity

Fibrinolytic balance and lupus anticoagulant in patients with repeated fetal loss

Fetal loss and relation between lupus antibobyes in early pregnanc

The Cenozoic igneous activity of Sardinia

Special Issue 1: a showcase of the Italian research in petrology: magmatism in Italy