[Measurement of anti-HTLV-I antibody titer in cerebrospinal fluid].

Anti HTLV-I antibody was measured in 590 cerebrospinal fluids (CSFs) employing a gelatin particle agglutination (PA) method. Anti HTLV-I antibody was detected in the CSFs from 24 patients (4.1%). The serum from the 24 patients also showed positive results. Out of the 24 patients, 11 cases (45.8%) had HAMs. Of the remaining patients 3 had ATLs with meningeal infiltration. Only 11 cases out of 24 patients were positive for anti HTLV-I antibodies when an immunofluorescence (IF) method was employed. This discrepancy of the results obtained by two methods may be explained by the presence of the patients whose CSFs contain anti HTLV-I antibodies of low titer. It is concluded that PA method is both sensitive and specific for the detection of anti HTLV-I antibodies in CSFs. Further, PA method is more convenient than IF method. So, it will be a very useful tool in the diagnosis of HTLV-I related neurological disorders and asymptomatic carriers.