Q. A 5-year-old male was admitted last night with a complaint of high fever and rash on his trunk and extremities. He had been sick for 7 days, and his parents reported that he had also developed red eyes, red and cracked lips, and swollen hands and feet. The patient has no significant past medical history, and he is up-to-date with his immunizations. On physical examination, the patient was febrile, and his heart rate was elevated at 130/min. He had a rash on his trunk and extremities, and his hands and feet were swollen and erythematous. Conjunctivitis and erythema of his lips was also present. The patient's cervical lymph nodes were mildly enlarged, and he had a reddish, swollen tongue with a strawberry appearance. Laboratory tests revealed elevated white blood cell count, elevated erythrocyte sedimentation rate, and elevated levels of C-reactive protein. An echocardiogram was performed, and it showed dilatation of the coronary arteries. Based on his clinical presentation and laboratory results, you diagnose the patient with Kawasaki's disease. You subsequently order him to be treated with intravenous immunoglobulin and aspirin. You also monitor him closely for the development of any coronary artery aneurysms. The patient responds well to treatment, and his fever has resolved this morning. Based on what you know about the treatment you ordered, which of the following is NOT a standard use for intravenous immunoglobulin?