Deep beneath Commonwealth Avenue rests a freezer farm stocked with more than 2 million frozen vials of human blood. The samples, sitting under a convenience store and butting up against tunnels beneath the T’s Green Line, are chilled to 155 degrees below zero Fahrenheit as they reside in giant metal vats pumped full of liquid nitrogen.
The blood came from some 150,000 volunteers who participated in research studies conducted by Brigham and Women’s Hospital during the past two decades and serves as a trove for scientists endeavoring to answer some of the most vexing questions in medicine.
Researchers, for example, can dip into the blood samples repeatedly to analyze the DNA of study participants who developed cancer or heart disease years after the initial study ended. Their goal is to find new ways to prevent chronic illness and to determine which patients get the biggest benefits from a particular drug, potentially paving the way to tailor medical treatments to individual patients.
One of the more pressing items on their agenda: to provide proof that reducing artery-damaging inflammation prevents heart attacks and strokes. To help answer that question, thousands of new blood samples will soon join those already in the freezer farm.
The samples are being mailed there for storage and will help determine whether two anti-inflammatory drugs — a cheap generic arthritis medication in a government-funded study and a more expensive brand name drug in a study paid for by the manufacturer — can save lives in those who previously had heart attacks.
Both studies stem from a landmark 2008 clinical trial that found that cholesterol-lowering statin drugs prevent heart attacks, strokes, and deaths in people who have normal cholesterol levels but elevated blood levels of a marker for inflammation.
Because statins are thought to both reduce inflammation and improve cholesterol, the study could not tease out the exact reasons for why the drugs prevented heart disease deaths, said Dr. Paul Ridker, a Brigham cardiologist who led the 2008 trial and is heading the new trials.
Ridker and the Brigham share a patent on the test used to measure the inflammation marker.
“We wanted two swings at the bat,” said Ridker, hoping that if one of the drugs failed, the other would still work to prove a theory he has been trumpeting for nearly 20 years: that inflammation is the driving force behind heart attacks and strokes.
Blood samples collected at the start and during the studies will be used to see whether either of the drugs lowers levels of inflammatory markers and whether those markers can predict who will stay healthy for years, even beyond the study duration, and who will be more likely to have a heart attack.
In its current location since 1993, the 10,500-square-foot freezer farm contains 45 giant vats that each hold 70,000 2-inch-long plastic vials. Smaller, older freezers can hold an additional half-million vials. Some of the storage space is shared with other institutions, such as Massachusetts General Hospital.
The $650,000 annual cost to maintain the lab is largely covered by the National Institutes of Health, but the expense of collecting and shipping the blood and pulling old samples must be covered by separate research grants.
“Our division’s biobank has been an invaluable resource, a true treasure trove, for our research studies,” said Dr. JoAnn Manson, chief of the division of preventive medicine at the Brigham.
In a previous study to determine whether folic acid supplements could prevent heart attacks in women, she and her colleagues used blood collected at the beginning and end of the study to monitor changes in levels of homocysteine, an amino acid associated with increased risk for heart disease.
While the folic acid was found to reduce levels of homocysteine, it did not lead to a reduction in heart events.
“This finding really cast doubt on the role that homocysteine played in heart disease,” Manson said.
Her latest study to determine whether high daily doses of vitamin D and fish oil supplements work better than placebos to prevent heart disease, strokes, and cancer will store blood from 16,000 study volunteers under Commonwealth Avenue to get a sense of nutrient deficiencies at the beginning of the study and whether improving those deficiencies can keep us healthy through the years.
“We’ll also be able to look at differences between nutrient blood levels in whites, compared with blacks,” said Manson, as well as genetic factors that might predict which people gain the biggest health benefits from supplements.
After perfecting a system of shipping kits and processing and storing blood over two decades, eight staff members who work at the freezer farm have the system down to a science. Each day, they expect about 100 new blood samples to arrive on ice from doctors’ offices all across the country and from study participants themselves.
Within hours of arriving, the blood is spun in a centrifuge into separate components for storage: red blood cells, plasma (which contains inflammatory markers), and white blood cells (which contain DNA) and quickly transferred into vials labeled with bar codes to make them easily identifiable if they need to be pulled for future research.
“We’ve never had a problem with our freezers, but if we did lose power, the temperature in the [sealed] vats wouldn’t change for days,” said Eleanor Danielson, who recently retired as the senior research manager at the facility.
Alarm systems, security cameras, and paging systems are in place just in case a malfunction or security breach ever occurred.
“It’s never happened,” said Danielson, “but we’re certainly prepared.”