[Vitamin D supplementation in institutionalized elderly. Effects of vitamin D3 (100,000 IU) orally administered every 3 months on serum levels of 25-hydroxyvitamin D]. / Supplémentation vitaminique D chez des sujets âgés placés en institution. Effets sur les concentrations sériques en 25-hydroxyvitamine D d'une administration orale trimestrielle de vitamine D3 (100,000 UI).

A clinical trial carried out during the autumn/winter season in 46 institutionalized elderly subjects (35 women, 11 men) (group mean age = 83 +/- 2 years) revealed a severe deficiency in vitamin D in these subjects (25-hydroxyvitamin D level less than or equal to 3 ng/ml). After oral administration of 100,000 IU of vitamin D3, an increase in 25-hydroxyvitamin D levels above the 10 ng/ml threshold was observed and maintained for three months. A second dose, administered after 3 months, made it possible to sustain this level. No sign of toxicity was detected, notably no trace of hypercalcemia. In contrast, no change in the deficit (25-hydroxyvitamin D level less than or equal to 3 ng/ml) was seen in the placebo population. Three-monthly administration of the moderate dosage of 100,000 IU of vitamin D3 all year round would offer a simple, effective and risk-free system to counteract vitamin D deficiency in the elderly and of preventing the risk of osteomalacia, thus reducing the incidence of fractures.

Hymenoptera venom immunotherapy. I. Induction of T cell-mediated immunity by honeybee venom immunotherapy: relationships with specific antibody responses.

The specific cell-mediated and humoral immune responses of 14 children allergic to honeybee venom were studied. An 8-day rush venom immunotherapy induced an increase in T proliferative (p less than 0.04) and T suppressive (p less than 0.003) cell-specific activities. Antibody variations, an increase in specific IgG4 (p not equal to 0.05), and a decrease in specific IgE (p less than 0.01) were observed 1 year later. Initial high T suppressive cell activity prevents T proliferative cell increase during rush venom immunotherapy. High initial levels of specific IgG1 and specific IgG4 have opposing effects on the increase in T suppressive cell activity, the former being positively correlated with intensive increase (r = 0.840; p less than 0.005), the latter negatively with T suppressive cell increase (r = -0.709; p less than 0.001). These data indicate that there are interrelationships between the cell-mediated immunity and the antibody responses in honeybee allergy.

Influenza vaccination in the elderly: improved antibody response with Imuthiol (Na diethyldithiocarbamate) adjuvant therapy.

To improve influenza vaccine efficacy in hospitalized elderly, we compared the evolution of antibody level after vaccination in three patient groups. A sample of apparently primo vaccinated elderly were randomized to receive either Imuthiol (Na diethyldithiocarbamate: group 1) or a placebo (group P). They were compared to patients who had been vaccinated annually for several years (group C). All patients were immunized in the same week. Antibody responses increase within 15 days to reach a plateau in group P and C, while they continue to increase in the Imuthiol treated group, reaching higher antibody levels 30 days after vaccination. This higher antibody rise in group I is essentially due to higher antibody responses in patients with initially low antibody levels and who exhibited at least a four-fold antibody rise. This effect of Imuthiol on influenza antibody responses was observed in spite of a lower nutritional status in this group, a condition that induces lower antibody responses. The higher antibody responses observed in the Imuthiol treated group allow longer protection against influenza.