NHA Phlebotomy Certification Practice Exam

What lab test is often associated with monitoring for cystic fibrosis?

1. Complete blood count

2. Urine culture

3. Sweat electrolyte test

4. Metabolic panel

The correct answer is: Sweat electrolyte test

The sweat electrolyte test is specifically designed to measure levels of sodium and chloride in sweat. This test is crucial for diagnosing cystic fibrosis because individuals with this genetic disorder typically have elevated sweat chloride concentrations due to a malfunction in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The elevated levels of these electrolytes in sweat provide a reliable indication of the presence of cystic fibrosis, making the test a key diagnostic tool for this condition. While other tests like a complete blood count, urine culture, or metabolic panel can provide important health information, they are not directly related to cystic fibrosis diagnosis or monitoring. The complete blood count provides insights into overall health and can indicate infections or other issues, but does not specifically target cystic fibrosis. A urine culture is used to detect infections in the urinary tract, which is not relevant to cystic fibrosis monitoring. The metabolic panel assesses various chemical substances in the blood but does not include indicators specific to cystic fibrosis. Therefore, the sweat electrolyte test stands out as the most appropriate test for monitoring cystic fibrosis.