CPT® Code 86384

The Nitroblue tetrazolium dye test (NTD), identified by CPT® Code 86384, is a diagnostic procedure utilized primarily for the screening of chronic granulomatous disease (CGD). CGD is a complex and heterogeneous genetic disorder characterized by the inability of phagocytes, a type of immune cell, to effectively kill certain ingested microorganisms. This deficiency results in the individual experiencing severe and recurrent pyogenic infections, which are infections caused by pus-forming bacteria. The NTD test functions by assessing the capability of specific immune system cells, particularly neutrophils, to convert a colorless chemical, nitroblue tetrazolium, into a deep blue pigment. In healthy individuals, the white blood cells will successfully undergo this color change upon exposure to the dye, indicating normal phagocytic function. Conversely, in individuals with CGD, the white blood cells will not exhibit this color change, thereby failing to turn blue, which serves as a critical indicator of the disease. This test is essential for early diagnosis and management of CGD, allowing for timely intervention and treatment to prevent serious infections.