Human T cell lymphotropic virus type 1 infection among U.S. thalassemia patients

Thalassemia is an inherited genetic disorder requiring multiple transfusions to treat anemia caused by low hemoglobin levels. Thus, thalassemia patients are at risk for infection with blood-borne pathogens, including human T cell lymphotropic viruses (HTLV) that are transmitted by transfusion of cellular blood products. Here, we examined the prevalence of HTLV among 234 U.S. thalassemia patients using sera collected in 2008. Sera were tested for antibodies to HTLV-1/2 using enzyme immunoassay (EIA) and a confirmatory western blot (WB) that differentiates between HTLV-1 and HTLV-2. Demographic information and clinical information were collected at study enrollment, including HIV and hepatitis C virus (HCV) status. Three patients (1.3%) were WB positive; two were HTLV-1 and one could not be serotyped as HTLV-1/2. All three HTLV-positive persons were HIV-1 negative and one was HCV seropositive. The HTLV seroprevalence was higher than that of HIV-1 (0.85%) and lower than HCV (18.8%) in this population. All three patients (ages 26-46 years) were diagnosed with β-thalassemia shortly after birth and have since been receiving multiple transfusions annually. Two of the HTLV-positive patients confirmed receiving transfusions before HTLV blood screening was implemented in 1988. We identified a substantial HTLV-1 seroprevalence in U.S. thalassemia patients that is much greater than that seen in blood donors. Our findings highlight the importance of HTLV testing of patients with thalassemia and other diseases requiring multiple transfusions, especially in recipients of unscreened transfusions. In addition, appropriate counseling and follow-up of HTLV-infected patients are warranted.

Assessing emerging infectious threats to blood safety for the blood disorders community

Technologic advances in diagnostic testing, vaccinations, pathogen inactivation, and vigilant donor screening have greatly reduced the risk of transmitting pathogens through blood transfusion. Nevertheless, transfusion-related infections and fatalities continue to be reported, and emerging pathogens continue to become an increasing threat to the blood supply. This threat is even greater to patients with blood disorders, who are heavily transfused and rely on safe blood products. This article describes some of the emerging and re-emerging transfusion-transmitted pathogens that have increased in incidence in the U.S. in recent years. Peer-reviewed articles and agency websites were the sources of information. The article focuses on the treatment of hereditary blood disorders including hemophilia and thalassemia, and hereditary bone marrow failure. A coordinated approach to addressing blood safety and continued development of sensitive diagnostic testing are necessary to reduce risk in an increasingly globalized society.