16th February 2024

A 42-year-old female presented with a six-week history of fever, arthralgia, and anorexia

A 42-year-old female presented with a six-week history of fever, arthralgia, and anorexia. Her investigation revealed:

Haemoglobin 115g/L (Normal 115-165 g/L)

White blood cell 11.0 x10⁹/L (Normal 3.6-11.0 x 10⁹/L) – Predominant neutrophils

Platelets 600 x10⁹/L (Normal 140-400 x10⁹/L)

CRP 120mg/L (Normal <5 mg/L)

Urea 16mmol/L (Normal 2.5-7.8mmol/L)

Creatinine 250μmol/L (Normal 45-84μmol/L)

A diagnosis of infective endocarditis is suspected.

What is the most likely finding when testing complement activity?

Select the SINGLE most appropriate option from the list below. Select ONE option only.