An 18-year-old college student is hospitalized due to a high fever and confusion. According to the patient's roommate, the symptoms started about 6 hours ago. The patient was feeling well this morning except for some nausea. She has had several episodes of pneumonia in the past and had bacterial meningitis a year ago, which was treated with ceftriaxone. Temperature is 39.1 C (102.4 F), blood pressure is 104/70 mm Hg, and pulse is 110/min. The patient is lethargic but is able to follow simple commands and give single-word answers with prompting. Physical examination reveals a petechial rash on the trunk and extremities, including the palms and soles. Neck stiffness and photophobia are also noted. Which of the following primary immune system impairments is most likely responsible for this patient's recurrent infections?

Question

An 18-year-old college student is hospitalized due to a high fever and confusion.  According to the patient's roommate, the symptoms started about 6 hours ago.  The patient was feeling well this morning except for some nausea.  She has had several episodes of pneumonia in the past and had bacterial meningitis a year ago, which was treated with ceftriaxone.  Temperature is 39.1 C (102.4 F), blood pressure is 104/70 mm Hg, and pulse is 110/min.  The patient is lethargic but is able to follow simple commands and give single-word answers with prompting.  Physical examination reveals a petechial rash on the trunk and extremities, including the palms and soles.  Neck stiffness and photophobia are also noted.  Which of the following primary immune system impairments is most likely responsible for this patient's recurrent infections?

Quizplus · Accepted Answer

Eductional Objective: Deficiency of the complement factors that form the membrane attack complex (C5-C9) results in recurrent infections of the lung and meninges by encapsulated bacteria (eg, Streptococcus pneumoniae, Neisseria meningitidis).

An 18-Year-Old College Student Is Hospitalized Due to a High