Diagnosis of HTLV-I infected seronegative neurological patients by polymerase chain reaction amplification in Martinique.

HTLV-I is a type C human retrovirus, endemic in Japan, central Africa, South America and the Caribbean, which causes adult T cell leukemia/lymphoma and chronic progressive paraparesis. Some neurological patients with chronic progressive myelopathies, but seronegative for HTLV-I have been reported in Martinique. We performed polymerase chain reaction (PCR), to look for the presence of HTLV-I genomic sequences in those patients. Two primers were chosen for gag and tax genes. Liquid hybridization was performed on the amplified products using an internal 32p labelled oligonucleotide as a probe. The hybridized material was run on a 6% polyacrylamide gel. Forty-three of forty-four seropositive subjects analysed as "positive controls" were positive for gag, but only 16/29 for tax. Twenty HTLV-I seronegative neurological patients with a symptomatology suggesting HAM/TSP were tested: 18 were found positive for at least one of the 2 oligonucleotide pairs. Two "negative controls": Moya-Moya and vascular brain failure were found negative. 8/9 subjects with uninterpretable WB were also studied by PCR, and 8 were found positive for at least one oligo pair. Our conclusion is that PCR methodology is able to detect genetic information related to HTLV-I in a number of cases where classical serology is negative.