A 2-week-old male newborn presents with fever (38.9°C), tachycardia (165 bpm), and omphalitis with erythematous umbilical skin that has separated incompletely. The mother denies antibiotic use during pregnancy. Laboratory studies reveal marked neutrophilia (WBC 28,000/μL with 89% neutrophils) and elevated CRP. Blood culture remains sterile after 48 hours. The patient has experienced recurrent skin and soft tissue infections despite appropriate antibiotic therapy. Which of the following best explains this patient's susceptibility to infection?
- A)Deficient terminal complement proteins leading to recurrent Neisseria infections
- B)Impaired neutrophil chemotaxis due to absent C5a
- C)Defective B cell maturation due to tyrosine kinase mutation
- D)Defective respiratory burst caused by absent superoxide generation
- E)Failure of neutrophils to adhere to endothelium because of CD18 deficiencyGABARITO
Explicação
Leukocyte adhesion deficiency is caused by deficiency of CD18, the beta 2 integrin subunit required for firm neutrophil adhesion to endothelium. Delayed umbilical cord separation, recurrent skin and mucosal infections, lack of pus, and persistent neutrophilia ... Ver explicação completa e trilha adaptativa →