Seroepidemiological studies have shown previously that
cancer patients are less likely to have
antibodies against the tumour suppressive adeno-associated virus (AAV) than control groups. To examine the influence of AAV
infection on the development of adult T-cell leukaemia
lymphoma (
ATLL), an endemic disease in Southern Japan that is caused by
infection with the human T-cell leukaemia virus type 1 (HTLV-I), the prevalence of serum
antibodies to AAV type 2 (AAV-2) was tested in healthy HTLV-I carriers (n = 39) and patients with
ATLL (n = 31). The results showed a significant difference in AAV-2 seropositivity between the two groups: Only 29% of the
ATLL patients had
IgG antibodies against AAV-2, whereas 84.6% of the healthy HTLV-I carriers were seropositive. Analysis of total serum
IgG and
antibodies against the Epstein-Barr virus (EBV) EBNA1
antigen showed that the lack of AAV
antibodies in patients was not due to an
ATLL-associated immune deficiency. The lower level of AAV-2 seropositivity in
ATLL-patients may indicate that AAV-2 antibody-positive HTLV-I carriers might be less likely to develop
ATLL or that loss of AAV-2
antibodies may parallel the development of disease.