Trumping nature with intellect and technology
Viruses are the ultimate opportunists, little bundles of genetic material that are pretty much useless on their own. But give them a place to live and they take over, reproducing themselves with abandon and trashing their host’s digs. To make matters worse, they are difficult to evict and have an annoying ability to change just enough to escape harm.
Understanding the workings of these culprits used to take days – even weeks – of growing them in cultures. Even then, doctors might not end up with a clear picture of how the virus worked – or how to combat it.
Then came PCR (polymerase chain reaction) technology, shaving days from the painstaking culture process. PCR gave doctors and researchers precise information about virus behavior at the molecular level – and quickly. It could churn millions of bits of DNA in just hours. Finally, science might be able to learn about a virus nearly as quickly as it could infect its host.
Seizing the moment
David Witte, MD, recognized PCR’s advantages early on – and was quick to adopt it at Cincinnati Children’s, some 15 years ago. It was one of the many decisions that have made Witte’s Division of Pathology a major player in helping physicians and researchers make giant strides in discovery, diagnosis and treatment.
Things have come a long way from those early days, says Pam Groen, who helped set up the process with Witte. Today, Groen manages the division’s busy anatomical pathology lab.
Solving a medical problem
“At the time, our physicians had a medical question with no answer. So every spare minute we had, we worked out the PCRs to solve it,” Groen recalls. “We would do the technical work, the clinicians would tell us how things were with the patients, and we would go back and forth. We worked through the ups and downs with the clinicians.”
The question fueling their work at that time was about post-transplant lymphoproliferative disease, a complication that follows solid organ transplants. It is now well recognized as infection with the Epstein-Barr virus, a virus many of us live with everyday. For a transplant patient with a weakened immune system, however, the virus can be deadly.
Building a reputation
The pathology team’s success using PCR to help clinicians diagnose and treat such problems soon led to requests from throughout the hospital.
“In the first year, we ran 44 tests,” Groen says. “Now we do more than 40,000 in a year.” The PCR lab employs five full-time staff and operates two shifts per day, six days a week.
The lab prides itself on providing results to doctors quickly, another advantage PCR has over growing viruses in culture, which can take days.
“Waiting for cultures isn’t always useful to a clinician who needs quick information,” says Witte.
The human factor
Improvements to PCR technology made over the years have automated and sped up many labor-intensive tasks, says Groen, but it is people who make the work of our Division of Pathology so exceptional.
“Technology is important. But it has to be matched by intellect. All of our technicians know that what they are handling is an irretrievable piece of information, and they treat it accordingly,” she says. “The information our technicians provide has exceptionally good integrity. Our staff don’t just push out a machine-generated piece of information. If something doesn’t look right, they pull everything together and say, ‘We have a result – does it make sense?’”
Developing the H1N1 Test
That combination of skill and technology came into play in a major way in 2009, as our region faced an epidemic outbreak of H1N1. There was no off-the-shelf assay specific to the H1N1 virus, so the PCR team developed one based on what was already known about the virus’ DNA sequences.
“By the time the wave hit, we were up and running,” Witte says. “The assay was widely used, and it gave doctors specific information about what the virus was doing in the community.”
It’s this ability to respond quickly and well that has kept the Division of Pathology’s laboratories in high demand by clinicians and researchers here and around the country.
“The field of viral PCR assays is constantly changing,” Witte says. “You have to have people who stay on top of what’s going on. Our professional staff are constantly assessing new methods and technology, investing and redeveloping the system. It’s one of the areas where they play a key role.”
Pathology In Basic Research
The Division of Pathology’s staff is crucial to the medical center in terms of the diagnostic expertise they provide to doctors in clinical practice. But they also provide core lab support for our basic scientists. The division’s technicians and pathologists work with Cincinnati Children’s researchers on a variety of studies exploring gene expression in tissues, proteins in certain cell types and how diseases develop.
Pathology serves as a core morphology lab for a number of NIH-funded projects both at Cincinnati Children's and the University of Cincinnati. In the past year, the morphology lab collaborated on more than 1,000 new research projects – generating some 22,000 histologic slides, 1,700 immuno-histochemical stains and 400 hours of electron microscopy support for these projects.
Electron microscopy (EM) allows a deep dive into understanding what is going on inside the cells – especially important when doctors are trying to understand the workings of rare diseases.
Cincinnati Children’s has the only remaining hospital-based electron microscope in the city. The hospital provides EM service for most of the major hospitals in the city and beyond, including Children’s Memorial Hospital in Chicago. Three full-time electron microscopy technicians oversee this operation, which added electronic scanning capabilities a few years ago.
Artists in the laboratory
The task of getting the snippet of tissue or bone to the stage where it can be closely analyzed and diagnosed by a pathologist is the work of the microtomist.
These skilled technicians – many of whom have decades of experience at their craft – prepare slides of biologic specimens so that pathologists can see the problem clearly and diagnose it with certainty.
Microtomists prepare slides, often from the tiniest fragment of an organ or bone. Tissue specimens are first hardened in paraffin then sliced with a microtome, a device that the microtomist uses to get specimens as thin as 5μm, a fraction of the thickness of a piece of paper. A special cryomicrotome allows the technician to prepare slides from frozen sections. She then stains the specimens in a series of reagent baths that color the cellular structures – and highlight anything that is amiss.
Microtomists blend science and art in a craft that technology cannot come close to. “Histology is an art form that no machine has been able to replicate,” says Pam Groen, who manages the anatomic pathology lab at Cincinnati Children’s.