3-in-1 Virus Killer May Help Transplant Patients Fight Often Fatal Infections

[Guest guest]

[This MAY be a real improvement for transplant patients. Let's hope so!]

Three-in-one virus killer prevents common, often fatal infections

A novel combination therapy drastically reduces the infection rate of

three viruses – and risk of death – in transplant patients with

compromised immune systems. The findings, to be reported in the Nov. 1

print edition of Nature Medicine, originate from a study conducted at

Baylor College of Medicine, The Methodist Hospital, and Texas

Children's Hospital.

The phase 1 trial, funded by the National Heart, Lung, and Blood

Institute, one of the National Institutes of Health, tested the first

multivirus killer of its kind, called Trivirus-specific cytotoxic T

lymphocytes (CTLs), which control infections caused by three

commonplace viruses – cytomegalovirus (CMV), Epstein-Barr virus (EBV),

and adenovirus. Although benign in people with normal immune systems,

the viruses can cause life-threatening illnesses in transplant

patients and others with compromised immune systems.

The CTLs proved effective and safe in all 11 bone marrow transplant

patients, who recovered completely within two to four weeks of being

treated without any side effects or toxicity. Preexisting therapies

for adenovirus have had little success – there is an 80 percent chance

of death following the development of adenovirus.

" Not only were patients prevented from getting these infections after

transplant, but those patients who had infections responded to the

T-cell therapy and did not require any other treatment, " said senior

author Dr. Bollard, assistant professor of pediatrics,

immunology, and medicine at BCM and a researcher at the Center for

Cell and Gene Therapy at BCM, Methodist and Texas Children's. " To make

dramatic recoveries like these was really quite something. "

The research team drew cells from bone marrow donors and " trained "

T-cells to target the three viruses before injecting them into

transplant recipients.

" Drugs only control the virus. They don't cure the underlying

problem, " said Bollard. " Whereas by introducing these specialized

T-cells, we are fixing the underlying problem. Using your own immune

system is preferable to chemical agents, which can have toxic side

effects. "

Although the CTLs must undergo further testing, the early results

suggest the combination therapy to be more, cost-effective, and safe

than traditional therapies and more practical than cell-based

therapies that target EBV and CMV separately, both of which are

carried in roughly 80 percent of all people. Adenoviruses are common

viruses carried in all populations.

" There is no safe and effective therapy for patients with adenovirus

infections at the moment, so if you get an infection after a

transplant it becomes very problematic, " said first author Dr. Ann

Leen, BCM instructor of pediatrics at the Center for Cell and Gene

Therapy. " So we trained certain T-cells to target this virus. "

Bollard envisions one day extending the application of CTLs to other

people with compromised immune systems, such as cancer patients

undergoing chemotherapy. The therapy could also potentially be used in

babies, who are more susceptible to adenovirus infections than other

age groups.

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