Soluble Triggering Receptor Expressed on Myeloid Cells in Severe Acute Pancreatitis
Condition: Acute; Pancreatitis
MeSH terms: Pancreatitis
Study type: Observational

Summary: 
      Early diagnosis of secondary infection of necrotic tissue in severe acute pancreatitis is
      extremely important. The investigators evaluated whether the level of soluble TREM-1
      (sTREM-1) in fine needle aspiration (FNA) fluid from patients who suspected infection is a
      good marker of secondary infection of necrotic tissue and an indicator of the proper
      treatment between drainage and necrosectomy.
    

Detailed description: 
      The major cause of death, next to early organ failure, is secondary infection of pancreatic
      or peripancreatic necrotic tissue, leading to sepsis and multiple organ failure. The
      diagnosis and treatment of infected necrosis in SAP remain a major challenge for clinicians.
      The necrotic infection is defined when microorganisms are isolated from the samples of
      ultrasound or computed tomography (CT) guided fine needle aspiration (FNA). Unfortunately, a
      negative biopsy result can not completely rule out infection and the repeated aspirations may
      lead to bleeding or iatrogenic infection. Moreover, whatever the microbiologic diagnostic
      procedure chosen, further laboratory processing and delays of 24 to 48 hours are required for
      definitive quantitative microbial culture results. Meanwhile, clinicians often feel
      uncomfortable about the diagnosis and may administer unneeded antibiotics while awaiting
      laboratory results.

      Secondary infection of necrotic tissue in SAP patients is virtually always an indication for
      intervention. The traditional approach is open necrosectomy to completely remove the infected
      necrotic tissue. This invasive approach is associated with high rates of complications (34 to
      95%) and death (11 to 39%).As an alternative to open necrosectomy, less invasive techniques,
      including percutaneous drainage and endoscopic (transgastric) drainage, are increasingly
      being used.These steps may postpone or even obviate surgical necrosectomy with reducing
      complications and death.It remains uncertain which intervention is optimal in terms of
      clinical conditions of these patients and the severity of local infection.

      Therefore, many biologic markers have been studied in an effort to improve the diagnostic
      rate and determine the the severity of necrosis infection but with disappointing results. The
      triggering receptor expressed on myeloid cells (TREM-1) is a member of the immunoglobulin
      superfamily whose expression on phagocytes is up-regulated by exposure to bacteria and fungi.
      TREM-1 mediates the acute inflammatory response to microbial products.[27] TREM-1 is also
      shed by the membrane of activated phagocytes and can be found in a soluble form in body
      fluids. We evaluated whether the lever of soluble TREM-1 (sTREM-1) in FNA fluid from patients
      who suspected infection is a good marker of secondary infection of necrotic tissue and an
      indicator of the proper treatment between drainage and necrosectomy.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        All patients 18 years of age or older who were hospitalized in our medical pancreatic
        intensive care unit (PICU) for least two weeks were enrolled in the study if there was a
        clinical suspicion of secondary infection of necrotic tissue.
      
Biospecimen description: 
      The FNA fluid specimens were performed under ultrasound or CT guidance, using a 18G needle
      attached to a 15 ml eppendorf tube. One percent xylocaine was used for local anaesthesia.
      Under real-time visualization, the needle was directed into the tissue part of the necrosis
      or pseudocyst.
    
Keywords: acute pancreatitis; Drainage; Pancreatic surgery; Biological Markers/analysis; Infection diagnosis; ROC Curve; Sensitivity and Specificity; Endoscopic ultrasonography