The present study has provided information on the
biometal contents of killed and dried Mycobacterium leprae as well as dermal
granulomas induced by the invading mycobacteria in various histological types of
leprosy patients. For comparison, the
biometal contents of the contralateral
leprosy-unaffected skin of the same patients also were measured. The study also reports changes of serum levels of the
biometals in these patients which were compared with those in healthy control subjects and patients with
skin tuberculosis. These data show that M. leprae is rich in
zinc. During the course of the evolution of the disease there is gross alteration of the dynamics of the inflammatory cell population that infiltrates into
leprosy granulomas, resulting in the alterations of
trace element contents of the disease-affected skin lesions. Interestingly, the changes of the
biometal contents in the
granulomas of the patients with
skin tuberculosis are similar to those in
leprosy patients. It is postulated that the significant decrease of the contents of
copper,
zinc,
iron,
calcium and
magnesium in the disease-affected skin in comparison to that of the contralateral healthy skin is a local effect, perhaps due to erosion or influx of
biometal-deficient inflammatory cells into the affected skin with eventual loss of connective tissue of skin and mobilization of tissue-bound microelements into the vascular compartment. On the contrary, the changes in
biometal levels in the sera of
leprosy patients appear to be a general effect perhaps due to the release of
interleukin-1, a product of inflammatory cells, causing hypercupremic, hypozincemic and hypoferremic responses in the hosts. Moreover, growth and multiplication of M. leprae, especially in polar
lepromatous leprosy patients with a high bacillary load, demand essential
biometals which may be mobilized into the bacterial bodies from the hosts. This perhaps results in the change in the homeostasis of the essential
biometals in the hosts.