Individuals suffering from conditions such as acute lymphoblastic leukemia and non-Hodgkin’s lymphoma often require a procedure known as hematopoietic stem cell transplant. Unfortunately, this procedure many times leads to infections caused by opportunistic viruses. In a clinical trial, infusions of broad spectrum T-cells were associated with a 94 percent response rate when used to treat patients with up to four viral infections. These results further support the effectiveness of this treatment option.
Hematopoietic stem cell transplantation involves the intravenous infusion of specific stem cells in order to help patients with damaged or defective bone marrow or immune systems. Hematopoietic stem cells, which are different from embryonic stem cells, divide to become more blood-forming stem stems or mature into white or red blood cells, according to the National Cancer Institute. This life-saving procedure leaves people very vulnerable to viral infections. Many viruses have no specific type of treatment and past T-cell approaches, although have worked, have also proven to be a long, complicated, and costly process, Med Page Today reported. "These viruses are a huge problem, and there’s a huge need for these products," lead author Ann Leen told NVO News.
In a recent study, now published in Science Translational Medicine, broad spectrum T-cells, known as virus-specific T-cells (VSTs) showed near perfect results in treating patients suffering from viral infections. There were also no observed or reported side effects from the T-cell infusion. "These benefits were obtained without toxicities," such as severe graft-versus-host disease," lead author Ann Leen and her colleagues reported to Med Page Today. Due to the small size of the study, which consisted of only 11 patients, researchers are not yet convinced that the transplanted T-cells can yet be called a medical breakthrough.
In a laboratory, scientists engineered T-cells that were specifically designed to recognize and attack viruses. To test the virus-specific T-cells, researchers infused between five and 20 million cells into 11 patients. The older the donor, the more T-cells a patients was given. Med Page Today speculates this may have to do with pathogen exposure increasing with age. There showed to be no link between the number of cells given to patients and safety or antiviral activity. Between 38 and 43 days after transplant, all the patients remained free of the viral infections for more than three months. The response rate for the 18 infections was 94 percent; 15 complete and two partial responses.
Source: Papadopoulou A, Gerdemann U, Katari UL, et al. Activity of Broad-Spectrum T Cells as Treatment for AdV, EBV, CMV, BKV, and HHV6 Infections after HSCT. Science Translational Medicine. 2014.