This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammation & Repair, Subject name: Pathology
Which of the following occurs in chronic granulomatous disease? 
Select and explain. 
A. Myeloperoxidase deficiency, B. Defective H2O2 production, C. Defective polymerization, D. Defective phagocytosis
B: Defective H2O2 production
Answer: B: Defective H2O2 production 
Explanation: Ans: b (Defective H2O2 production) Ref: Ananthanarayan, 7th ed, p. 157; Harrison, 16th ed, p. 354Chronic granulomatous disease is a disorder of microbial killing characterized by decreased ability of neutrophils to produce H2O2 Patients become succeptible to catalase producing organisms which destroy the small amount of H2O2 in these cells leading to bacterial killing.Granulomas are produced as a 2nd line of defence against organisms, that normally would be removed by acute inflammatory response.Enzyme defect - N ADPH oxidaseScreening test - NBT test (nitroblue tetrazolium dye not reduced by neutrophils in vitro)