Complete Myeloperoxidase Deficiency: Beware the "False-Positive" Dihydrorhodamine Oxidation.

Myeloperoxidase deficiency is the most common inherited phagocyte disorder (1:2000) and causes an abnormal dihydrorhodamine oxidation test, which also is seen in chronic granulomatous disease. A patient with Candida meningitis and low dihydrorhodamine oxidation signal was diagnosed with chronic granulomatous disease but actually had compound heterozygous myeloperoxidase deficiency.