HTLV-I PROVIRAL DNA AMOUNT CORRELATES WITH INFILTRATING CD4-CORD FROMPATIENTS WITH HTLV-I-ASSOCIATED MYELOPATHY( LYMPHOCYTES IN THE SPINAL)

A quantitative method utilizing polymerase chain reaction was employed to evaluate the amount of human T-cell leukemia virus type I (HTLV-I) proviral DNA in the affected spinal cords from patients with HTLV-I-a ssociated myelopathy/tropical spastic paraparesis (HAM/TSP). Central n ervous system (CNS) tissues were obtained at post-mortem from five pat ients with HAM/TSP, who vary in the duration of illness from 2.5-10 ye ars, and one patient with adult T-cell leukemia (ATL), who had leukemi c cell infiltration in the CNS. The presence of HTLV-I pX and pol sequ ences in the CNS tissues were demonstrated in ail patients examined. I n HAM/TSP, the proviral DNA quantified in the thoracic cord was 0.002- 2 copies per 100 tissue cells, and that in the peripheral blood mononu clear cells (PBMC) was 2-8 copies per 100 PBMC. The proviral DNA amoun t in the thoracic cord of the patient with ATL was 0.4 copies per 100 tissue cells. An apparent propensity for the amount of integrated HTLV -I in the thoracic cord to decrease with the disease duration in patie nts with HAM/TSP was observed. The decline in HTLV-I proviral DNA amou nt in the thoracic cord lesions was paralleled with the alteration of proportion of CD4(+) T lymphocytes in patients with HAM/TSP. These fin dings suggest that preferential virus reservoir may be infiltrating CD 4(+) T lymphocytes in the spinal cord lesions of patients with HAM/TSP , and HTLV-I infection in the CNS of patients is declining with the di sease duration in spite of the chronic course of neurological manifest ations at least in some patients with HAM/TSP.