A pilot study of HTLV-1 infection in high-risk individuals & their family members from India

Background & Objectives: Human T lymphotropic virus-I (HTLV-I) has been ass ociated with adult T cell lymphoma/leukemia (ATLL). There are Indian studie s on HTLV-I infection among people with sexually transmitted infection, but no large study has been conducted on individuals with haemato logical mali gnancies. In this group of individuals, serology is known to under-diagnose HTLV-I infection. This study was carried out to identify serologically and where possible with molecular techniques, HTLV-I infection in individuals with haematological malignancies' To understand the modes of transmission, family members of individuals with proven HTLV-I infection were also studie d. Individuals with sexually transmitted infection (STI), blood donors and pregnant women were also studied. Methods: Particle agglutination test was used to detect antibody to HTLV-I. HTLV genome was amplified by polymerase chain reaction (PCR) and detected with probes by digoxiginin (Dig) ELISA. Results: There was no serological evidence of HTLV-I infection among the he althy blood donors and pregnant women studied. High prevalence of anti-HTLV -I antibody was identified in the patients with haematological malignancies (8 of 86 patients, MIX) and a lower prevalence in individuals with STI (8 of 670 individuals, 1.2%). In the STI group, all 8 individuals seroreactive to HTLV-I were coinfected with human immunodeficiency virus (HIV). In the group with haematological malignancies, three of 22 (13.6%) patients with l eukemia, 3 of 11(27.3%) with cutaneous T-cell lymphoma (CTCL) and 2 of 53 ( 3.8%) with lymphoma were reactive for anti-HTLV-I antibody. In this group, PCR identified all the seroreactive individuals tested. There were also ser onegative infected individuals who were only identified by PCR. There was a lso a large number of seronegative family members who were only positive by PCR. Interpretation & conclusion: The study revealed a strong disease associatio n of HTLV-I with haematological malignancies and evidence for both horizont al and vertical transmission of the infection in the Indian population. HTL V-I infection appears to be common among family members of individuals with HTLV-I associated haematological malignancies.