High prevalence of human T-lymphotropic virus type I carriers among patients with myelodysplastic syndrome refractory anemia with excess of blasts (RAEB), RAEB in transformation and acute promyelocytic leukemia.

We examined human T-lymphotropic virus type I (HTLV-I) infection among patients with myelodysplastic syndrome (MDS), refractory anemia with excess of blasts (RAEB)/RAEB in transformation (RAEBt) and acute myelogenous leukemia (AML). The study population consisted of 151 patients: 46 with MDS RAEB/RAEBt and 105 with AML (M1, n=15; M2, n=39; M3, n=18; M4, n=19; M5, n=9; M6, n=3; M7, n=2). As a reference, we examined 92 patients with refractory anemia (RA) and 405 patients with cardiovascular diseases (CVD). Thirteen patients with RAEB/RAEBt (28.3%), 11 with AML (11.6%), 27 with RA (29.3%), and 45 with CVD (11.0%) were positive for HTLV-I. Seven AML patients with HTLV-I infection had M3 acute promyelocytic leukemia (APL). The prevalences of HTLV-I infection among patients with RAEB/RAEBt (P < 0.001), APL (P=0.001), and RA (P < 0.001) were significantly higher than that in patients with CVD. The prevalences of HTLV-I infection were still significantly higher in patients with RAEB/RAEBt (P=0.007), APL (P=0.017) and RA (P < 0.001) than in those with CVD matched by sex and age. Platelet counts and survival times of RAEB/RAEBt patients with infection were significantly lower than those of patients without infection.