Defective leukotaxis in patients with lepromatous leprosy.

Sera from patients with lepromatous leprosy contain a leukotactic (chemotactic) inhibitor that irreversibly inhibits a variety of chemotactic factors. The presence of this inhibitor correlates with lack of skin reactivity to a variety of antigens. The inhibitor appears to be similar to a serum factor recently termed the chemotactic factor inactivator. The presence in leprosy sera of this inhibitor may be responsible for some of the defects of cellular inflammatory responses found in patients with lepromatous leprosy.