Background: Diagnosis of Spontaneous Bacterial Peritonitis (SBP) depends
mainly on ascetic fluid culture which may be negative in spite of the clinical suggestion of
SBP and high ascetic fluid neutrophilic count.
Aims: This study aimed to evaluate the biological importance of amyloid A biomarker in
both serum and ascetic fluid to diagnose SBP as early as possible and to compare it to other
markers (C-reactive protein (CRP), and the neutrophil-to-lymphocyte ratio (NLR)).
Methods: This study included 37 patients with hepatic ascites; twenty-two of them had
SBP, and 15 patients did not have SBP. Serum and ascetic fluid amyloid A, ascetic fluid
neutrophil, C-reactive protein, and neutrophil-to-lymphocyte ratio were measured in all
subjects before the start of antimicrobial chemotherapy to the infected ones.
Results: Both the serum and ascetic fluid amyloid and also, CRP were significantly higher
in patients infected with ascetic fluid than others. The cut-off point of serum amyloid A for
early detection of SBP was 9.25ug/ml with the high sensitivity and specificity. For ascetic
amyloid A, the sensitivity and specificity were 90.09% and 60% at cut-off point 2.85ug/ml,
Conclusion: Amyloid A in serum and ascitic fluid can be considered as a good biomarker
for early diagnosis of SBP.