Abstract
Type 1 immunity appears to be diminished in healthy Japanese carriers of human T‐lymphotropic virus type I (HTLV‐I), but type 2 status remains undetermined. To further examine the subclinical effect of HTLV‐I on host immunity, we measured serum antibodies to the Epstein–Barr virus (EBV) in 415 healthy Japanese adults to broadly characterize type 1 status. Levels of the type 2 biomarkers total immunoglobulin E (IgE), soluble CD23 (sCD23), and soluble CD30 (sCD30) were assessed in 167, 142, and 135 of these subjects, respectively. We analyzed the association of HTLV‐I with levels of each serum marker using linear and logistic regression. Altered EBV antibody profiles that are consistent with deficient type 1 immunity were more prevalent in HTLV‐I carriers than non‐carriers (odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.5–5.3). Carriers also had 45% lower total IgE levels (P = 0.04) than non‐carriers. In contrast, HTLV‐I infection was not significantly associated with elevated levels of sCD23 or sCD30. These observations are contrary to our expectation of elevated type 2 biomarkers among carriers. We conclude that in this population, healthy carriers of HTLV‐I may have subclinical deficiencies in both type 1 and type 2 immunity, and that type 1 and type 2 immunity are not necessarily reciprocal in persons with subclinical immune dysregulation. J. Med. Virol. 78:847–852, 2006. © 2006 Wiley‐Liss, Inc.