A 22-year-old man initially chalked up his fever and weakness to the flu—until, too weak to get out of bed, he called an ambulance. It was not until he was hospitalized with failing kidneys and "off-the-charts" blood test results before doctors discovered the real cause of his symptoms, Lisa Sanders reports for the New York Times Magazine.
Feeling like the flu
The patient first noticed something was wrong when, one day after his graduate school classes, he felt exhausted. He took a nap, but felt even worse when he woke up, with muscle soreness, extreme weakness, and a fever—symptoms which led him to think he had the flu, Sanders reports.
But later that evening, when the patient went to the bathroom, he discovered something strange—his urine was dark, "the color of Coca-Cola," Sanders reports. He went back to sleep, but the following morning, when he woke up feeling weaker than ever, he finally called 911.
Landing in the hospital
The patient was transported to the ED of CHA Cambridge Hospital in Massachusetts, where a flu test came back negative. However, the man's blood tests suggested his kidneys were failing, his liver might be damaged, and that—based on his higher-than-normal white blood cell count—he might have been fighting off "severe infection," Sanders reports.
However, when the patient told his doctor, Frances Ue, that he had been working out a few days before he got sick, Ue sent samples of the man's blood to look for creatine kinase (CK), an enzyme that increases when muscle tissue is injured.
According to Sanders, extreme exercise can lead to this type of injury, and if CK or other muscle components leak into the bloodstream, they can cause a condition called rhabdomyolysis. A typical level of CK is between 100 and 200. The man's test showed his CK level was beyond what the test had the capability to measure—over 40,000. Subsequent testing found that his initial CK level was 189,000, and it later peaked at 364,000.
However, the patient told the doctor his exercising hadn't been especially extreme—just three times a week to help manage stress—and he didn't use any drugs or supplements either to help build muscle or recreationally.
Ue and her colleagues still thought exercise-induced rhabdomyolysis was the cause, but they sent off several tests to look for other possible causes, such as hepatitis A and Epstein-Barr virus. Whatever the cause, however, Ue told the patient that they needed to flush out his kidneys with fluid—immediately.
An answer is discovered
While looking through medical literature, Ue discovered a paper describing two young patients who had developed severe rhabdomyolysis following a moderate workout. These patients had been born with an abnormality in the way they processed food that led their bodies to run out of fuel when stressed or working hard.
Thinking the patient may have one of these rare conditions, Ue referred him to a neurologist. Eventually, the patient met with Courtney McIlduff, a neurologist at Beth Israel Deaconess Medical Center, who discovered via genetic testing that the patient had been born without the ability to make the enzyme carnitine palmitoyltransferase type 2 (CPT2).
According to Sanders, when the body runs out of carbohydrates for energy, it generally uses fat for fuel. However, people with CPT2 deficiency cannot do that well. As a result, muscle cells are injured when the body runs out of fuel, leading to pain and discolored urine.
As of now, there is no cure for CPT2 deficiency, Sanders reports. Instead, patients manage their diet and lifestyle and take a supplement providing fats that their bodies can break down. In the year and half since his diagnosis, the man has joined an online community to help manage his condition, saying he is "determined to learn how to take care of the only body he'll ever have," Sanders writes. (Sanders, New York Times Magazine, 7/14)