A medical problem stirs a societal debate
Experts disagree on the danger of sickle cell trait - and the specter of racism makes answers hard to find.
By LISA GREENE
Published October 8, 2006
Aaron O'Neal collapsed and died during college football practice, not in the hands of prison guards.
Yet his death was eerily similar to that of Martin Anderson, the teenage Florida boot camp inmate who drew worldwide headlines this year. Just as with Anderson, doctors immediately disagreed about what killed O'Neal, a 19-year-old University of Missouri freshman. In each case, at least one pathologist laid blame on a condition that isn't supposed to be deadly: sickle cell trait.
The questions surrounding Anderson's death after being roughed up at a Panama City boot camp are only the most public in the debate about the dangers to people with sickle cell trait, an inherited blood mutation that normally has no symptoms. A medical examiner who blamed sickle cell trait for Anderson's death was greeted with howls of protest, not only from those who believed the camp guards responsible, but also from skeptical medical specialists who treat sickle cell anemia. A second autopsy said Anderson suffocated.
And yet, dozens of deaths have been attributed by doctors to sickle cell trait. The U.S. Air Force once banned pilot recruits with the trait because it believed them to be at extra risk of sudden death. Trainers for sports teams, where the risk of problems is highest, plan to hold a summit on the issue next year.
There's a lot at stake: More than 3-million Americans, including 1 in 12 African-Americans, have sickle cell trait. What precautions should they take to prevent a risk that most experts say is extremely rare - and a few even say doesn't exist?
The debate raises questions of racial politics. Although people of different races have sickle cell, some fear black athletes might face discrimination. Police might use sickle cell trait to cover brutality. Medical questions can become clouded.
"That's why you get the controversy," said Dr. Michael Bell, chief medical examiner for Palm Beach County. "It's easy to say this group can't do this, or this group must take these precautions. You can't do that with a group that is largely asymptomatic, where there's a small number that will develop a complication that's life-threatening."
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People with two copies of the sickle gene have sickle cell anemia, a serious, painful disease that can kill. But people with the trait, who carry only one copy of the abnormal gene, simply never die from the condition, some experts said.
"Sickle cell trait is not causing deaths," said Dr. Willarda V. Edwards, president and chief operating officer of the Sickle Cell Disease Association of America. "To make that diagnosis based on an autopsy report is incorrect."
What's more, Edwards said, overstating the danger risks hurting the millions who have the trait.
"It really does a big disservice to the ... people in the U.S. that we know have sickle cell trait, that will cause a lot of discrimination in their ability to do things," she said.
Other doctors side with Edwards. In the Anderson case, doctors called the first autopsy done by Bay County Medical Examiner Charles Siebert Jr. "totally preposterous" and "ridiculous."
The family called in a prominent New York pathologist, Dr. Michael Baden, who said flatly that "sickle trait does not harm you."
But other doctors say the lack of awareness poses a different kind of risk to people with sickle cell trait - one that could be deadly.
"Michael Baden saying it does not harm you - considering the literature, he may as well have walked out and said the world is flat," said Dr. Jon Thogmartin, Pinellas-Pasco medical examiner.
These doctors - including many pathologists, sports medicine specialists and academic researchers - agree that most people with sickle cell trait will never have a problem. Thogmartin says the chances are less than getting hit by lightning.
But they do point to a long list of case reports and studies that say that in rare circumstances, complications from the trait can kill.
Even Baden said recently that in "extremely rare" cases, the trait can cause problems, although he said he firmly believes the trait played no role in Anderson's death.
"Sickle cell trait evolved as a protection, as an advantage against malaria," he said. "The trait evolved as a help, not a hazard."
Dr. Mark Gladwin likes to compare normal red blood cells to wet water balloons. They're soft, squishy and slippery, able to slide easily through blood vessels.
"A sickle cell is the equivalent of partially freezing that balloon," said Gladwin, chief of the vascular medicine branch of the National Heart, Lung and Blood Institute.
Inside a sickle cell, abnormal hemoglobin, the protein that carries oxygen, can form long fibers. That makes the cell flatten, forming a crescent or sickle shape that can't move easily through blood vessels - just as you couldn't push a frozen balloon through a pipe, Gladwin said.
As blood flow is blocked, parts of the body can't get enough oxygen. The result can be excruciating pain, organ and muscle damage, strokes and other complications.
When people have sickle cell anemia, all their red cells can sickle. But people with sickle cell trait have some abnormal blood cells, too, even though many don't know it and the cells usually don't cause a problem.
And people with the trait have other differences. Their kidneys might not function quite as well, so they can become dehydrated more easily. If the level of oxygen in their blood gets very low, such as at high altitude or during heavy exercise, their abnormal cells can start to sickle.
At first, Thogmartin said, people in sickle crisis may complain of pain but not seem seriously ill. They're not overheated. Their pulse doesn't race.
"It fools people, while in their vascular system ... is just a cascade of events that gets worse and worse," he said.
Once sickling begins, blood cells can't carry life-giving oxygen elsewhere in the body. It's a vicious cycle: The oxygen drop prompts more sickling. Muscles and organs start to die.
One widely quoted study examined deaths during exercise among military recruits. The study, published in the New England Journal of Medicine in 1987, found that for recruits with sickle trait, the risk of dying during exercise was 28 times greater. Until the mid 1980s, the U.S. Air Force banned pilot recruits with sickle trait, but discontinued that practice after a lawsuit claiming discrimination.
Wendy Hunter didn't know her identical twin sons, Devaughn and Devard Darling, had sickle cell trait when she sent them off to play football at Florida State University.
The 18-year-old twins went to practice together one morning in February 2001. Devaughn had just finished a session of drills when he collapsed. He died an hour later.
The medical examiner found no definite cause of death but noted that Devaughn had sickle trait.
Now Hunter says she wishes more people knew about the risk.
"People need to be aware that it could cause something if they're not properly hydrated or rested," she said.
If her son had known the risks linked to sickle cell trait, preventing his death might have been as simple as an extra water bottle.
"It's a senseless death, that anybody has to die over something like that," said Hunter, of Texas.
Cases like Darling's and Aaron O'Neal's have gotten the attention of trainers and sports medicine doctors. The National Athletic Trainers' Association plans to hold a summit on sickle cell trait in February. On the agenda: whether college athletes should be screened.
At the University of Oklahoma, incoming athletes are screened during their physicals, said Scott Anderson, the school's head athletic trainer. He also co-chairs the national group's task force on sickle cell in athletics.
Trainers don't keep those who test positive from playing but try to take a few precautions, he said.
"What we seek to do is avoid placing them in a position where they have sustained running without periods of rest and recovery," Anderson said. "If they have complaints of leg pain, back pain, shortness of breath, we're going to pay heed to those symptoms."
But the question for Edwards and other sickle cell advocates is whether screening could lead to limits.
"When widespread screening started back in the 1970s, there were adverse reactions," said Dr. E. Randy Eichner, professor emeritus at the University of Oklahoma and team internist for the school's football team. "Some people with sickle cell trait were denied insurance, or lost jobs, which is a shame. We need education and prudence."
Other researchers said that, especially in today's legal climate, some coaches might not offer scholarships to athletes with the trait. A British sociologist asked whether the trait was being used to exonerate police actions in deaths in custody.
"There are no different statistics in their ability to be involved in football, or in the military, or any strenuous activity, than anyone who does not have sickle cell trait," Edwards said.
Anderson said nobody wants to put limits on those with the trait. He pointed to the case of 12-year-old Bobby Stephens, who died in Tampa this summer after football practice. Stephens had sickle cell trait and another rare blood mutation.
"We're not looking to decrease or limit participation, we're looking to increase and expand opportunities for participation," he said. "Take Bobby Stephens as an example. He no longer has an opportunity to participate in sport."
To Thogmartin, the lack of public knowledge about the risk is irresponsible.
"If you know you have it, you can decrease your chances (of a crisis) to zero," he said. "Are we going to allow people to die, or be hurt, or lose their kidneys, or accept that there's a very tiny, miniscule risk, and make people aware?"
Devard Darling says he isn't worried about athletes with sickle trait facing discrimination. Too many professional athletes have already proven that the trait isn't a roadblock, he said.
Darling is among them: He's now a receiver for the Baltimore Ravens. He is careful to stay hydrated, but the trait doesn't stop him.
"I still work out very hard. It's just a matter of being aware of your body," he said. "I think I work out harder than most athletes do."
But Darling said athletes need to know more about the potential risk. He said he favors sickle screening for high school and college athletes.
"If there's something about your body, I think you should know about it," he said. "It can affect your health, your play. In certain situations, it can affect your life."