Role of ascitic fluid C3 in spontaneous bacterial peritonitis

The C3 component of complement tends to be reduced in cirrhosis and patients with reduced ascitic fluid C3 concentration and reduced opsonic activities have been shown to be predisposed to SBP [1]. To compare the level of ascitic fluid C3 concentration in cirrhotic patients with and without spontaneous bacterial peritonitis to determine its possible protective role against acquiring infection. This is a prospective case-control study in which we recruited 45 cirrhotic patients presenting with ascites, of which 25 showed evidence of SBP. All patients had diagnostic paracentesis, received the appropriate treatment, discharged and followed-up monthly for 3 months, with ascitic fluid C3 measurement. Ascitic fluid C3 was compared between both groups at baseline and for three successive reading over 3 months. It was also compared in the same patients group over this interval and correlated with other AF parameters at baseline reading. Ascitic fluid C3 is reduced in cirrhotic patients with SBP and stays lower compared with those without the infection after the first episode. So we conclude that C3 plays an important role in the local defense of ascitic fluid and needs further long term follow-up studies to evaluate its role as a predictor of prognosis for cirrhotic ascitic patients.