Thalidomide is a drug that is being used in several diseases with an immunological component, but the effects on the different immune functions have only been studied partially. Therefore, we studied the effect of thalidomide on PPD- or Con-A-induced proliferation of human mononuclear cells. We found no direct effect of thalidomide at up to 50 μg/ml on the cultures. Cells taken from subjects 6 h after ingestion of 200 mg of thalidomide proliferated equally well to PPD and Con-A than cells taken prior to drug administration. Plasma taken from subjects that ingested 200 mg of thalidomide 6 h before did not affect the proliferative response of their own cells when added to the culutures. Plasma from rabbits that were injected with doses 5 or 15 times higher than the dose given to humans did not diminish the proliferative response of human mononuclear cells to PPD. We conclude that neither thalidomide nor its metabolites affect the proliferative response of human mononuclear cells.

Discovery of armadillos (Dasypus novemcinctus) as animals susceptible to infection with My cobacterium leprae, has allowed the experimental study of leprosy to extend beyond the limits of the mouse fo otpad. Armadillos, however, do not all become equally infected with a given dose of M. leprae. Therefore, it would be advantageous to establish a technique for the early identification of those animals bearing the disease. Infection in armadillos originates systemic involvement which includes liver damage and the consequent release of LDH into circulation before the appearance of the clinical signs of the disease. In this study, where an enzyme linked immunoassay for the detection of anti mycobacterial antibodies was developed, those very same animals that showed an increase in their serum LDH activity showed the presence of anti-M. leprae antibodies to significant titres and eventually the presence of disease. From the results with some animals, it appears that the presence of antimycobacterial antibodies occurs before the elevation in the serum LDH activity. Periodical measurement of both antimycobacterial antibodies and LDH activity in the sera of M. leprae-inoculated armadillos may help one to detect the early infection, decide whether or not an animal is indeed infected, and decide how to proceed with the animals under investigation. The results also reveal some of the immunological and biochemical consequences of the M. leprae-infection in the armadillo.