Sepsis in Newborns - C-Reactive Protein

Sepsis in Newborns - C-Reactive Protein

 

Systemic infections are responsible for a significant number of hospitalizations during the neonatal period.  Nonspecific symptoms make the differentiation between bacterial and viral illnesses difficult and make the use of markers such as C-reactive protein useful as an aid in differentiation.

Epidemiology

  • Incidence – WHO (2000) estimates that 42% of neonatal mortality is caused by infections

Pathophysiology

  • C-reactive protein (CRP) is an acute phase reactant that binds to:
    • Polysaccharides present in many bacteria, fungi and protozoal parasites
    • Phosphocholine
    • Phosphatidylcholines such as lecithins
    • Polyanions such as nucleic acids
  • Once complexed, CRP becomes an activator of the classical complement pathway by:
    • Recognizing potentially toxic autogenous substances released from damaged tissues
    • Binding these toxic substances
    • Detoxifying or clearing the toxic substances from the blood
  • CRP peaks and begins to decrease within 48 hours of acute insult if no other inflammatory event occur

Clinical Presentation

  • Nonspecific signs and symptoms
    • Fever
    • Lethargy
    • Irritability
    • Apnea
    • Abdominal distention
  • Rapid progression of sepsis with accompanying shock without early treatment

Diagnosis

  • Laboratory testing
    • Good evidence supports use of CRP to rule out sepsis in full-term infants
      • Additional, newer studies suggest similar efficacy in pre-term infants
      • Use in conjunction with white blood cell count and differential
      • Obtain serial quantitative levels 24 hours after onset of symptoms of possible infection and obtain second measurement 24 hours later
      • Levels ≤ 10 mg/L indicate low probability of infection
    • Future role for procalcitonin measurements in neonatal sepsis

See Also