Which laboratory finding commonly occurs in patients with chronic granulomatous disease?

Chronic granulomatous disease (CGD) is a genetic disorder that affects the immune system, specifically the ability of phagocytes (including neutrophils) to produce reactive oxygen species due to a defect in the NADPH oxidase complex. This defect hampers the body's ability to kill certain types of bacteria and fungi, leading to recurrent infections and the formation of granulomas.

In patients with CGD, one of the key laboratory findings is the absence of color change in the dihydrorhodamine (DHR) test. The DHR test assesses the ability of phagocytes to produce reactive oxygen species. In a healthy immune response, when phagocytes encounter pathogens, they undergo respiratory burst, which leads to the production of reactive oxygen species that reduce dihydrorhodamine. This reduction results in a color change from colorless to green as the dihydrorhodamine becomes rhodamine. However, in individuals with CGD, the lack of functional NADPH oxidase means that there is no respiratory burst, hence no color change occurs during the DHR test, indicating impaired oxidative burst capability.

This finding is pivotal for diagnosing CGD, as it directly reflects the underlying inability of leukocytes to produce the substances required to