Perspectives and Practices of Athletic Trainers and Team Physicians Implementing the 2010 NCAA Sickle Cell Trait Screening Policy

Sickle Cell Screening in Adults: A Current Review of Point-of-Care Testing

In adults, the sickle cell solubility test (SCST) is the most common screening test to determine the presence of hemoglobin S (HbS) within a blood sample. The assay is inexpensive, rapid, highly sensitive and specific. However, the SCST cannot accurately quantify the level of HbS in a test sample and requires confirmatory testing to distinguish between sickle trait and sickle cell disease. Despite these limitations, it remains the standard screening tool for HbS in a variety of settings such as screening in the US military or by the National Collegiate Athletic Association. With an increased awareness of the importance of screening for sickle cell in adults, we herein describe the current sensitivity, specificity, positive predictive value, and negative predictive value of this test. We also review overall clinical utility of this laboratory measure and briefly discuss new point-of-care techniques designed to overcome the SCST's shortcomings.

Challenging the dogma of the healthy heterozygote: Implications for newborn screening policies and practices

Heterozygous (carrier) status for an autosomal recessive condition is traditionally considered to lack significance for an individual's health, but this assumption has been challenged by a growing body of evidence. Carriers of several autosomal recessive disorders and some X-linked diseases are potentially at risk for the pathology manifest in homozygotes. This minireview provides an overview of the literature regarding health risks to carriers of two common autosomal recessive conditions on the Recommended Uniform Screening Panel: sickle cell disease [sickle cell trait (SCT)] and cystic fibrosis (CF). We also consider and comment on bioethical and policy implications for newborn blood screening (NBS). Health risks for heterozygotes, while relatively low for individuals, are often influenced by intrinsic (e.g., other genomic variants or co-morbidities) and extrinsic (environmental) factors, which present opportunities for personalized genomic medicine and risk counseling. They create a special challenge, however, for developing screening/follow-up policies and for genetic counseling, particularly after identification and reporting of heterozygote status through NBS. Although more research is needed, this minireview of the SCT and CF literature to date leads us to propose that blanket terms such as "healthy heterozygotes" or "unaffected carriers" should be superseded in communications about NBS results, in favor of a more nuanced paradigm of setting expectations for health outcomes with "genotype-to-risk." In the molecular era of NBS, it remains clear that public health needs to become better prepared for the full range of applied genetics.

Case Report: Exertional rhabdomyolysis in a spin class participant with sickle cell trait

Exertional rhabdomyolysis is more common in sickle trait due to a predisposition to dehydration and inability to concentrate the urine. Spinning, an indoor cycling workout, has been associated with exertional rhabdomyolysis in recent reports. A consequence of rhabdomyolysis is acute kidney injury, which may be expected to be more common in patients with sickle trait. We report a case of spinning induced rhabdomyolysis in a woman with sickle trait that did not result in renal injury. "Spin rhabdo" is thought to be more severe than other causes of exertional rhabdomyolysis and is associated with higher creatine kinase levels than other causes of exertional rhabdomyolysis. Therefore, individuals with known sickle trait should consider visiting their physician prior to participation in spin classes for the first time. We might also consider voluntary screening for sickle trait in at risk populations prior to enrolling in spin classes given that many patients are unaware of their sickle trait status.

Balancing exercise risk and benefits: lessons learned from sickle cell trait and sickle cell anemia

Development of exercise guidelines for individuals with sickle cell trait (SCT) and sickle cell anemia (SCA) is hampered by the need to weigh the benefits against risks of exercise in these populations. In SCT, concern for exercise collapse associated with sickle cell trait has resulted in controversial screening of student athletes for SCT. In SCA, there exists unsubstantiated concerns that high-intensity exercise may result in pain and other complications. In both, finding the "right dose" of exercise remains a challenge for patients and their providers. Despite assumptions that factors predisposing to adverse events from high-intensity exercise overlap in SCT and SCA, the issues that frame our understanding of exercise-related harms in both are distinct. This review will compare issues that affect the risk-benefit balance of exercise in SCT and SCA through these key questions: (1) What is the evidence that high-intensity exercise is associated with harm? (2) What are the pathophysiologic mechanisms that could predispose to harm? (3) What are the preventive strategies that may reduce risk? and (4) Why do we need to consider the benefits of exercise in this debate? Addressing these knowledge gaps is essential for developing an evidence-based exercise prescription for these patient populations.

Implementation of the NCAA Sickle Cell Trait Screening Policy: A Survey of Athletic Staff and Student-athletes

OBJECTIVE

To describe the perspectives and experiences of athletic trainers, coaches, and student-athletes approximately three years post-implementation of the NCAA sickle cell trait (SCT) screening policy.

PARTICIPANTS

Two-hundred and eight student-athletes, 32 athletic trainers, and 43 coaches from 10 NCAA Division I (DI) institutions in North Carolina from January to June 2014.

METHODS

Two online surveys were used to assess knowledge, perspectives, and experiences.

RESULTS

Athletic staff were more supportive than student-athletes of the need for the policy. Noted challenges included variation in implementation and follow-up for SCT-positive athletes, financial costs to institutions and athletes, and timing of the screening.

CONCLUSIONS

More education about SCT is needed for student-athletes and athletic staff in order to help make the implementation more successful. All parties need to be in agreement regarding the importance of knowing which student-athletes have SCT and how that information will be utilized.