Viral specific IgG and IgM antibodies in the CSF of patients with tropical spastic paraparesis.

The cerebrospinal fluid (CSF) from seven West Indian migrants to the United Kingdom with tropical spastic paraparesis were studied by antigen immunoblotting for specific anti-HTLV1 oligoclonal IgG and IgM. Eight CSFs from five patients were positive for specific IgG and negative for IgM; three CSFs from two patients were positive for IgM and negative for IgG. No patient had both IgG- and IgM-positive CSF. Those patients with IgM only had disease of the shortest duration. When looking for evidence that neurological damage is caused by HTLV1, both IgM and IgG should be examined.