Q. An 8-month-old male infant is brought to the emergency department because of a convulsion. The patient was delivered at term to a 24-year-old woman without any major medical history. The infant's medical history is significant for 5 otitis media and pneumonia infections in the last 3 months. Vital signs show blood pressure: 95/60 mmHg, heart rate:110 bpm, temperature: 38.5 degrees Celsius. The patient is admitted for further evaluation. Cerebrospinal fluid analysis is positive for coxsackievirus. Immune deficiency is suspected. Which of the following is expected in the immune assay in this patient?