Can you answer this question?
A 3 year-old male is brought to your office for the evaluation of recurrent infections and persistent hunger, and not gaining weight. His mother reports that his medical history is significant for recurrent skin abscesses with staphylococcus aureus. Recently he started to complain about abdominal pain that starts one to two hours after a meal. When he vomits, the ingested food is ejected forcefully falling several feet away. Physical examination findings include several abscesses over both upper extremities, tenderness over the epigastric area.
You ordered an ultrasound of his abdomen which confirmed what you suspected, pyloric stenosis. Then you thought, “but why is this boy getting recurrent skin abscesses?” Incrementally, you ordered some laboratory tests to investigate this boy’s condition. Results came as follows
CBC: anemia, leucocytosis, and elevated ESR
Skin abscess culture: Positive for Staphylococcus aureus, Burkholderia cepacia and Serratia marcescens
Dihydrorhodamine (DHR) test: Positive
Nitroblue tetrazolium test: Positive
Which of the following best describes the pathogenesis of the disease affecting this patient?
- Dysfunction of NADPH oxidase system
- Defective cellular transportation
- Low C1 esterase inhibitor
- Defective formation of actin cytoskeleton in T cells
- T cells lack functional CD40 ligands and cannot signal B cells to switch
Explanation. Correct answer is A. Patient’s age, gender, recurrent skin infections, abscesses, symptoms of pyloric stenosis (persistent hunger, not gaining weight, projectile vomits, abdominal pain), presence of Catalase positive organisms in the culture, positive Dihydrorhodamine (DHR) test, and Positive Nitroblue tetrazolium test will help you clinch the diagnosis: Chronic Granulomatous disease, which is characterized by a defective NADPH oxidase system
B is incorrect because defective cellular transportation is seen in Chédiak-Higashi syndrome.
C is incorrect because Low C1 esterase inhibitor is seen in hereditary angioedema
D is incorrect because defective formation of actin cytoskeleton in T cells Wiskott-Aldrich syndrome
E is incorrect because ‘T cells lack functional CD40 ligands and cannot signal B cells to switch’ seen in HyperIgM syndrome