ATI RN
Pediatric Immune Disorder Test Questions Questions
Question 1 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 2 of 5
Severe neutropenia is defined as absolute neutrophil count (ANC) less than
Correct Answer: A
Rationale: Severe neutropenia is defined as ANC <500/μL, increasing infection risk significantly.
Question 3 of 5
Leukemoid reactions (WBC count >50,000/μL) are caused by all the following EXCEPT
Correct Answer: D
Rationale: Chronic granulomatous disease causes defective neutrophil function, not leukemoid reactions, which are triggered by severe infections like shigellosis.
Question 4 of 5
All the following matching about genetic deficiencies of plasma complement components and associated clinical findings are true EXCEPT
Correct Answer: A
Rationale: C4 deficiency is more strongly linked to systemic lupus erythematosus than discoid lupus, making this pairing less accurate.
Question 5 of 5
How are B-cell and T-cell antigen receptors distributed?
Correct Answer: C
Rationale: B and T cell receptors are distributed clonally, meaning each lymphocyte expresses a unique receptor specific to an antigen, expanded upon activation.