| Abstract: | Summary Since the demonstration of the lymphocyte as a mediator of delayed hypersensitivity our understanding of this immune response has advanced tremendously. It is now recognised that the lymphocyte acts as the sensitized cell and the macrophage as the indicator cell. The following mechanism for delayed hypersensitivity has been suggested. Antigen→macrophage super antigen→lymphoblast→sensitized lymphocyte→migration inhibitory factor→macrophage. The anergy to tuberculin testing in active tuberculosis and other states is better understood. It is believed that in active tuberculosis there is an inhibitory factor in the serum. The recognition of thein vitro correlates of delayed hypersensitivity has provided yet another method of detecting this immune response. It is more sensitive than the dermal tests. It is hoped that this will prove useful in the diagnosis and management of tuberculosis, a disease where hypersensitivity plays a large part in the pathological process. From the Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-16. |
