Depressed immunity and impaired proliferation of hematopoietic progenitor cells in patients with complete spinal cord injury

The bone marrow is supplied with both sensory and autonomic neurons, but th eir roles in regulating hematopoietic and immunocompetent cells are unknown . Leukocyte growth and activity in patients with stable and complete spinal cord injuries were studied. The innervation of the bone marrow below the i njury level lacked normal supraspinal activity, that is, a decentralized bo ne marrow. Lymphocyte functions were markedly decreased in injured patients . Long-term colony formation of all hematopoietic cell lineages, including dendritic cells, by decentralized bone marrow cells was substantially reduc ed. It was concluded that nonspecific and adaptive lymphocyte-mediated immu nity and growth of early hematopoietic progenitor cells are impaired in pat ients with spinal cord injuries. Possibly, this reflects cellular defects c aused by the malfunctioning neuronal regulation of immune and bone marrow f unction. (Blood. 2000;96:2081-2083) (C) 2000 by The American Society of Hem atology.