Review and Self-Assessment

Review and Self-Assessment

Deficits in the complement membrane attack complex (C5-8) are associated with infections of what variety?

A. Catalase-positive bacteria

B. Neisseria meningitidis

C. Pseudomonas aeruginosa

D. Salmonella spp.

E. Streptococcus pneumoniae

The answer is B.

(Chap. 1) Deficiencies in the complement system predispose patients to a variety of infections. Most of these deficits are congenital. Patients with sickle cell disease have acquired functional defects in the alternative complement pathway. They are at risk of infection from Streptococcus pneumoniae and Salmonella spp. Patients with liver disease, nephrotic syndrome, and systemic lupus erythematosus may have defects in C3. They are at particular risk for infections with Staphylococcus aureus, S. pneumoniae, Pseudomonas spp, and Proteus spp. Patients with congenital or acquired (usually systemic lupus erythematosus) deficiencies in the terminal complement cascade (C5-8) are at particular risk of infection from Neisseria spp such as Neisseria meningitidis or N. gonorrhoeae.

A 63-year-old man has chronic obstructive pulmonary disease and presents to your office for routine follow-up. He has no complaints currently and feels well. His most recent forced expiratory volume in 1 second (FEV₁) was 55% predicted, and he is not on oxygen. He has received one dose of pneumococcal vaccine 7 years previously. He is asking if he should receive another dose of pneumococcal vaccine. According to the guidelines of the Centers for Disease Control and Prevention, what is your recommendation?

A. He does not require further vaccination unless his FEV1 drops below 50% predicted

B. He does not require further vaccination until he reaches age 65

C. He should be revaccinated today

D. He should be revaccinated 10 years after his initial vaccine

E. No further vaccination is recommended as a single dose is all that is required

The answer is B.

(Chap. 5) Pneumococcal vaccination has been recommended for all individuals at any age with a variety of chronic medical conditions, including chronic respiratory disease, chronic heart disease, chronic liver failure, diabetes mellitus, asplenia, and chronic kidney disease. Determining when to revaccinate individuals has been somewhat controversial. The current recommendations are to revaccinate individuals’ ages 19–64 five year after the initial vaccine if they have chronic renal failure or nephrotic syndrome, asplenia, or other immunocompromising conditions. All other individuals should receive a one-time revaccination at age 65 and older if they were vaccinated 5 or more years previously and were age <65 at the time of original vaccination.