Suppression of tuberculin skin reaction in healthy HTLV-I carriers from Japan.
Although it is thought that infection with human T-lymphotropic virus type I (HTLV-I) is immunosuppressive, this has not been clearly demonstrated among healthy carriers, and there are no data concerning delayed-type hypersensitivity (DTH). To evaluate this hypothesis, DTH to purified protein derivative (PPD) of tuberculin was measured in 126 healthy adults from an endemic area for HTLV-I infection in southern Japan. Among the 39 HTLV-I carriers, only 15% had detectable induration following PPD exposure, compared to 46% of the 87 non-carriers. In addition, the size of erythema among those carriers with a positive reaction was about 70% of that among non-carriers. Overall, there was a significantly inverse association between the degree of DTH response and prevalence of antibody. In relation to subjects with strong to moderate reaction, those with negative or indefinite reaction were 6 times more likely to be a carrier. This association was much stronger among subjects aged 60 years or older than among younger persons. These findings indicate that there is subclinical immunosuppression among HTLV-I carriers, which increases with age.
Tachibana
N
N
Second Department of Medicine, Miyazaki Medical School, Japan.
Okayama
A
A
Ishizaki
J
J
Yokota
T
T
Shishime
E
E
Murai
K
K
Shioiri
S
S
Tsuda
K
K
Essex
M
M
Mueller
N
N
D000328:Adult; D000367:Age Factors; D000368:Aged; D002353:Carrier State / Q000276:immunology*; D005260:Female; D015490:HTLV-I Infections / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed; D007108:Immune Tolerance; D008297:Male; D008875:Middle Aged; D014374:Tuberculin Test