Chronic Granulomatous Disease: Acetaminophen Use can Trigger a False-Positive Diagnostic Test

According to a story from, the results of recent research have revealed that recent use of acetaminophen can trigger a false-positive result on the dihydrorhodamine (DHR) test. This test is commonly used to diagnose chronic granulomatous disease (CGD), a rare genetic disorder. Acetaminophen, also called paracetamol, is a widely used medicine for pain relief. It is available over-the-counter.

About Chronic Granulomatous Disease

Chronic granulomatous disease (CGD), which is also called Bridges-Good syndrome, describes a diverse group of hereditary genetic diseases. They are characterized by the appearance of granulomata (small clusters of macrophages, a type of immune system cell) in many organs throughout the body. This is the result of immune cells not being able to form the reactive compounds used to destroy pathogens. It is caused by mutations affecting the NOX2 or CYBB gene, which is found on the X chromosome. Therefore, most cases of chronic granulomatous disease are X-linked. Infections are the most common symptom and appear due to the compromised state of the immune system. Infections may include skin infections, pneumonia, bacterial or fungal blood infections, septic arthritis, and osteomyelitis. The agents that cause infection are almost never dangerous in healthy people. Treatments include antibiotics, interferon, and stem cell transplant. A stem cell transplant can cure the disease but comes with serious risks. To learn more about chronic granulomatous disease, click here.

About the Research

These findings could seriously complicate the accuracy of this test:

“We found that people could have abnormal results on this test, if they had taken acetaminophen shortly before the test, even if they didn’t have CGD.” – Dr. Christina Yee, Boston Children’s Hospital

The effect is temporary and the abnormal results only appear if the drug had been used recently before the test was conducted. The reason for this effect appears to be linked to one of the key indicators of chronic granulomatous disease: impaired oxidative function affecting neutrophils, a type of white blood cell. These cells experience this same effect when exposed to acetaminophen.

The researchers compared the test results of 15 adults, who took the DHR test both before and after being dosed with acetaminophen. All of these participants saw unusual results if they took the drug before getting the DHR test. The effect was most pronounced in people who received multiple doses or who had been dosed within the last 24 hours.

Learn more about these findings and their implications here.


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