Cosmopolitan HTLV-Ia subtype among Spanish native patients.

HTLV-I isolates exhibit peculiar geographic distributions, but are believed not to be associated with different pathogenic outcomes of these retroviral infections. We have analyzed two HTLV-I-infected Spanish native patients: one patient with a T-cell lymphoma had not travelled to HTLV endemic areas, and the other patient had a paraparesis and had travelled to many HTLV endemic areas such as South America, and Central and South Africa. LTR proviral sequences of these isolates were amplified and sequenced to generate phylogenetic trees with different reported HTLV-I strains in order to subtype them. Spanish isolates clustered into the cosmopolitan HTLV-Ia subtype. It is important to know which HTLV-I subtypes are circulating in Spain. It is possible that a subtype other than the cosmopolitan one is present in Spain, especially African subtypes due to the proximity of this continent and the rise of immigration from Central and South African countries.