Aryan, a 14-year-old boy presented with chronic diarrhea and weight loss. History reveals that he has repeated attacks of respiratory tract infections with Pseudomonas aeruginosa. His younger brother died from a severe respiratory infection at the age of 7. Which of the following agents is most likely to improve this patient’s condition?

**Core Concept**
The patient's symptoms suggest a chronic immunodeficiency disorder, likely due to a defect in the phagocytic system. Chronic infections with Pseudomonas aeruginosa, particularly in the respiratory tract, are characteristic of chronic granulomatous disease (CGD).

**Why the Correct Answer is Right**
The patient's condition is consistent with chronic granulomatous disease (CGD), a genetic disorder caused by mutations in the genes encoding components of the NADPH oxidase complex. This complex is essential for the production of superoxide, a key antimicrobial agent produced by phagocytes. In CGD, the NADPH oxidase complex is defective, leading to impaired superoxide production and increased susceptibility to catalase-positive bacteria, such as Pseudomonas aeruginosa. The use of IFN-γ (Interferon-gamma) can improve the patient's condition by enhancing the antimicrobial activity of macrophages and neutrophils.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because antibiotics alone may not address the underlying immunodeficiency and may not be effective against catalase-positive bacteria.
* **Option B:** This option is incorrect because corticosteroids may actually worsen the condition by suppressing the immune response.
* **Option C:** This option is incorrect because antifungal agents are not indicated in this case, as there is no evidence of a fungal infection.

**Clinical Pearl / High-Yield Fact**
Chronic granulomatous disease (CGD) is a rare genetic disorder characterized by recurrent infections with catalase-positive bacteria, particularly Pseudomonas aeruginosa. The use of IFN-γ can improve the antimicrobial activity of phagocytes and is a key component of the management of CGD.

**Correct Answer:** C. IFN-γ (Interferon-gamma)

✓ Correct Answer: B. Pancreatic lipase