Status of soluble ST2 levels in serum of HTLV-1 infected individuals.

ST2 is a member of IL-1 receptor family expressed on Th2 cells and regulates Th2 responces. The gene of ST2 encodes soluble ST2 (sST2) and the transmembrane ST2 (ST2L) isoforms through alternative mRNA splicing. The discovery of IL33/ ST2 signaling pathway, has drawn a great scientific attention to this system. sST2 has been shown to be an indacating factor in various infl ammatory conditions. This study aims to evaluate serum sST2 levels in HTLV-1 infected patients. This study included 49 HTLV-1 seropositive cases of which 14 were sympthomatic. Controls consisted of 30 healthy volunteers. sST2 level was measured using a quantitative ELISA assay and the results of the study groups were compared. Corroborating the previous reports, sST2 was lower in females (P = 0.003). The sST2 levels was slightly increased in HTLV-1 patients, though such increase was not statistically significant (P = 0.91), in addition sST2 level did not correlate significantly to the disease duration (P = 0.78). Despite some other chronic viral infection, HTLV-1 seems not to induce high serum sST2. However owing to relatively high normal variation of sST2 levels and rather small sample size, we stongly recommend further reseach with preferably larger sample size to evalute sST2 in HTLV-1 infected patients.