ATI RN
Pediatric Immune Disorder Test Questions Questions
Question 1 of 5
Which of the following C1 subunit has the catalytic activity that cleaves C4 and C2 complement proteins?
Correct Answer: C
Rationale: C1s, activated by C1r, cleaves C4 and C2 to form C3 convertase.
Question 2 of 5
The virus in the above question spreads from the respiratory tract and causes viremia. Which antibody class would be most important in fighting the virus as it spreads through the body?
Correct Answer: D
Rationale: IgG dominates systemic immunity, neutralizing viruses during viremia.
Question 3 of 5
If a person had a genetic defect affecting perforin production, which cells and immune function would be affected?
Correct Answer: A
Rationale: Perforin is critical for cytotoxic T cells and NK cells to kill target cells.
Question 4 of 5
A 40-day-old, previously healthy, fullterm female infant manifests fever, lethargy, and poor feeding for 12 hours. Physical examination reveals a lethargic child with vital signs of RR 70, HR 185, BP mean 25, T 39.50°C. The peripheral perfusion is poor, the chest reveals retractions, the abdomen is soft and reveals persistence of the umbilical cord, and the extremities are cool. Laboratory studies reveal a white blood cell count of 65,000 and a platelet count of 105,000. Family history reveals that a male sibling died suddenly at the age of 2 months, 10 years prior to the birth of this child. The most likely diagnosis is
Correct Answer: D
Rationale: Leukocyte adhesion deficiency (LAD) presents with delayed umbilical cord separation, recurrent infections, and leukocytosis (WBC 65,000) due to impaired neutrophil migration. The family history suggests an autosomal recessive condition like LAD.
Question 5 of 5
The MOST appropriate method to correct the immune deficiency in complete DiGeorge syndrome is
Correct Answer: D
Rationale: Complete DiGeorge syndrome lacks T-cell function due to absent thymus; thymic transplantation restores T-cell immunity, addressing the root cause.