Activation of macrophages microglia with the calcium-binding proteins MRP14 and MRP8 is related to the lesional activities in the spinal cord of HTLV-I associated myelopathy

Macrophages and microglia may play an important role in the pathogenesis of chronic inflammatory process in HTLV-I associated myelopathy (HAM) and tro pical spastic paraparesis (TSP). However, the etiology and cellular mechani sm of chronic inflammation are poorly understood in HAM/TSP,To help to defi ne the roles of macrophages and microglia we analyzed the various patterns of macrophage and microglia activation in the central nervous system (CNS) of HAM/TSP using several monoclonal antibodies recognizing the different st ates of activation. The results indicate that a large number of macrophages and microglia express both MRCP14 and MRP8 inactive-chronic inflammatory l esions of the patients with a short duration of illness (2.5 years). In the patient whose duration of illness was 4.5 years, perivascular and parenchy mal macrophages rind microglia were reactive for MRP8 but not for NIRP14. I n contrast, MRP14 and MRP8 were negative on the perivascular and parenchyma l macrophages and microglia in inactive-chronic lesions and in controls. Th is study suggests that (a) activated macrophages and microglia as well as C D4(+) T lymphocytes and CD8(+) cytotoxic T lymphocytes are main components of the inflammatory process in the CNS in HAM/TSP, (b) activation of macrop hages and microglia is related to the amount of HTLV-I proviral DNA in situ .