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Pearls and Pitfalls

American Society of Hematology Opposes Sickle Cell Trait Screening

A Voice from Left Field

Eichner, E. Randy MD, FACSM

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Current Sports Medicine Reports: May/June 2012 - Volume 11 - Issue 3 - p 106-108
doi: 10.1249/JSR.0b013e318256786e
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Introduction

In January 2012, the American Society of Hematology (ASH) weighed in on sports medicine. They issued a policy statement on screening for sickle cell trait (SCT) and athletic participation. The ASH policy opposes the April 2010 National Collegiate Athletic Association (NCAA) policy requiring all Division 1 institutions to screen all incoming athletes for SCT (18).

The ASH statement calls for more research, of course, and marshals its opposition into three bullet points: 1) ASH does not support testing or disclosure of SCT status as a prerequisite for participation in athletics, 2) ASH recommends universal interventions to reduce exertion-related injuries and deaths because this approach can be effective for all athletes irrespective of SCT status, and 3) ASH believes the NCAA policy has the potential to harm the athlete and the larger community with SCT (18).

I believe ASH is wrong on all three of these forays into sports medicine. After studying the makeup of the ASH workshop that led to this pronouncement, I also wonder about the expertise of ASH in sports medicine. Let me explain.

ASH Does Not Support SCT Screening of Athletes

Among the ASH reasons for opposing the NCAA mandate are 1) the Army stopped screening recruits, 2) there is “lack of scientific evidence to substantiate a significant correlation between SCT in athletes and training-related sudden death,” 3) the “extremely small number of deaths in a highly prevalent carrier state implies that other genetic or environmental factors play a role,” and 4) “rhabdomyolysis and exertional collapse also occur in individuals without SCT” (2,18).

It is true that the Army quit screening. More on that later. The other three ASH points miss the mark. Solid epidemiologic evidence ties SCT to deaths in football. From 2000 to 2010 in NCAA Division 1 football, an alarming 16 conditioning deaths occurred, and 10 (63%) were tied to SCT, an excess of up to 21-fold over the estimated 3% to 4% of all such players with SCT (6). ASH also is misguided to characterize the number of deaths as “extremely small.” I estimate that, from 2000 to 2010 in Division 1, exertional sickling killed 1 in 485 SCT football players per year. Others report that SCT is tied to a 37 times higher risk of death in NCAA football (12). In light of this risk, a recent editorial, following the ASH pronouncement, endorsed screening football players (11). A Canadian view also rebuts ASH, concluding, “Whether it is 9 deaths in 10 years or 1 death in 50 years, this screening has potential to protect the health of these athletes and ensure that they have successful sports careers.” This view is from the Sickle Cell Association of Ontario (17).

ASH says rhabdomyolysis and exertional collapse also occur without SCT. This is true but misses the point, which is that rhabdomyolysis per se — from novel overexertion in non-SCT athletes — is almost never fatal.

The first case series of exertional rhabdomyolysis was described in 1960 in Marine recruits doing squat jumps; of 19 hospitalized, all did fine (13). In 1967, another 23 cases were reported in Marines; all did fine (10). Forty Marines in one platoon were hospitalized for rhabdomyolysis in 1971; all did fine (3). Ditto for 11 more Marines in a 1974 report and for 63 Air Force trainees in a 2010 report (1,4). This totals 156 military cases of exertional rhabdomyolysis; all did fine, most returned soon to duty, and few had recurrences.

The story is the same for athletes. In three team outbreaks of rhabdomyolysis in football training, 28 were hospitalized; all did fine (7). In a recent swim team outbreak, seven were hospitalized; all did fine, as did eight female lacrosse players (5). In a new outbreak in a college women’s lacrosse team, six were hospitalized; all did fine (15). Ditto for high-school students after harsh physical tests; in two outbreaks in Taiwan, 187 got rhabdomyolysis, at least 20 were hospitalized, and all did fine (5,16). This totals 236 athletes and other young people with exertional rhabdomyolysis; all did fine.

The only exception is exertional heat stroke (EHS), with or without stimulant use, but here, the deaths seem to be from brain and other vital-organ heat injuries, not from the modest rhabdomyolysis. The pearl is, absent EHS, the only exertional rhabdomyolysis that can kill a healthy athlete is exertional sickling. Note too that, of 32 firefighters hospitalized for rhabdomyolysis after a demanding fitness test, the only one who died had SCT (9).

ASH Touts “The Army Way” for College Sports

ASH touts universal interventions. They say, “Universal interventions are used successfully by…the U.S. Army…athletics can be made safer with these measures, thereby rendering screening for and disclosure of SCT unnecessary” (2). They add, “The Army discontinued screening for SCT in 1996, and their intervention measures have been fully implemented, which have resulted in a marked decline in deaths due to exertional heat illness (EHI) in all recruits, including soldiers with SCT” (18).

ASH is misguided. Based on a hypothesis that severe EHI is the trigger for sickling in SCT, Army researchers conducted an EHI prevention study from 1982 to 1991. They cut intensity and increased rest breaks and hydration in the heat and responded quickly if recruits fell out. In the decade of this study, 15 SCT deaths were expected, but none occurred (15). In a sense, 15 SCT lives were “saved.” This never-published study led the Army to stop screening recruits (they still screen commandos) and continue the EHI prevention program to prevent SCT deaths.

ASH seems oblivious to what happened next. Soon after the study ended, Army SCT deaths rose back to or near baseline. The Army knows their SCT deaths continue apace; that is why in late 2011, they held a conference on SCT: “Mitigating Risk for Warfighters and Athletes.” Based on unpublished Army data on 25 exercise-related SCT deaths presented at that conference, along with other military SCT deaths I know of, I estimate that from 2002 to 2011, about 15 exertional sickling deaths occurred in the Army. In other words, the Army had as many SCT deaths in the past decade as lives they “saved” in the decade of their “universal interventions” study.

The reason the Army has failed is that, in the Army as in sports, most SCT deaths are triggered not by severe EHI but by unwise intensity, as when unscreened recruits with SCT are ordered to run a timed 2 miles. We reported two such Army deaths on the track; one recruit died sickling on her fifth try to run fast enough to suit the Army (8).

The pearl is “the Army way” does not work even in the Army. Who then, besides ASH, thinks it can work in the hands of football coaches?

ASH Says Screening May Harm the SCT Athlete

ASH concludes that the NCAA policy attributes risk imprecisely, obscures considering other risk factors, lacks adequate counseling, and by stigmatization and racial discrimination may harm athletes and the larger community with SCT. This final scattershot blast is fuzzy thinking aimed wrongly. It partly may reflect hangover attitudes from decades ago, when mass community screening led to confusion and errors. ASH could help, not hinder, by teaching that SCT is malarial, not racial.

In reply to this ASH pronouncement, team physicians argue that it can be as vital to know SCT status as to know that athletes have asthma or diabetes (11), and the Canadian sickle cell organization says that stigmatization is a fair price to pay for saving lives (17). Bear in mind that the NCAA first offered SCT screening to black athletes in 1975, that some colleges have screened off and on since then, that fairly widespread Division 1 screening has been in place for 5 to 10 years, and that no evidence exists of stigmatization of SCT athletes.

Also, to those who say no evidence exists that screening saves lives, I say no exertional sickling death has occurred yet where the athlete was known to have SCT and the institution used reasonable tailored precautions like those in the NCAA Sports Medicine Handbook.

Consider the Source

Finally, ponder the 22-member workshop that led to this ASH pronouncement. Study their credentials. You see experts in psychology, public health, minority health, genetics, bioethics, and sickle cell advocacy, along with researchers from the Army and the National Institutes of Health, and several hematologists with strong academic ties and expertise in sickle cell disease. Two members, from the Army, know exertion-related sickling and exercise physiology. The other 20? Not so much. They are esteemed in their fields but not “in the field.” I wonder what they know about how, where, when, or why athletes collapse in the field. None of the 22 is in sports medicine, and no one from sports medicine was invited — no team physician, no athletic trainer, and no one from NCAA or from any sports medicine organization. I ask you, should this ASH group pronounce on SCT and athletes? If so, maybe the American College of Sports Medicine should pronounce on bone marrow transplantation.

The author declares no conflict of interest and does not have any financial disclosures.

References

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© 2012 American College of Sports Medicine