Prostaglandin-dependent regulation of the in vitro proliferative response to mycobacterial antigens of peripheral blood lymphocytes from normal donors and from patients with tuberculosis or leprosy.

The response to soluble mycobacterial antigens of peripheral blood mononuclear cells, from most normal donors, tuberculosis patients or cases of tuberculoid leprosy (TT/BT) was enhanced by the addition of indomethacin. In contrast, indomethacin caused no enhancement of the response of cells from lepromatous leprosy (BL/LL) cases. Moreover the addition of 10-5 M prostaglandin E2 (PGE2) failed to inhibit the proliferative responses of cells from the BL/LL patients, although it markedly inhibited the responses of peripheral blood mononuclear cells from the other groups. The addition of PGE2 or indomethacin to cells which had been precultured for 48 hr had no significant effect on the proliferative responses of cells from any of the groups of donors. These results suggest that a normal, prostaglandin-dependent, indomethacin-sensitive regulatory mechanism is absent from the peripheral blood mononuclear cells of BL/LL patients.