Triggering receptor expressed on myeloid cells-1 is a member of the immunoglobulin superfamily of receptors that is specifically expressed on the surfaces of monocytes and neutrophils.TREM-1 expression is increased in infectious diseases and is associated with the release of soluble TREM-1 (sTREM-1).There has been demonstrated that the value of plasma sTREM-1 levels as an indicator of sepsis was superior, although other studies reported that the value of sTREM-1 for diagnosing sepsis was inferior.An increasing number of studies indicate that there are increased levels of sTREM-1 in body fluid samples for the following diseases and conditions: sepsis, pneumonia, pleural effusion, septic arthritis, meningitis, peritonitis, and uterine cavity infection.

Inflammation is now believed to play a major role in the pathophysiology of AKI. It is hypothesized that the initial insult results in morphological and/or functional changes in vascular endothelial cells and/or in tubular epithelium in sepsis models. Then, leukocytes including neutrophils, macrophages, natural killer cells, and lymphocytes infiltrate into the injured kidneys and induce the generation of inflammatory mediators. Whether urine sTREM-1 could also be detected and its significance in sepsis and AKI has not been reported yet.

The present study focused on the value of serum & urine sTREM-1 for sepsis identification, severity and prognosis assessments, and potential sepsis-related AKI. We also made comparisons between sTREM-1 and WBC counts, serum CRP, serum PCT, urine output,CC SCr, and BUN among sepsis patients.

Inclusion Criteria:

1. Male and female aged 18 years old and over;
2. clinically suspected infection;
3. fulfilled at least two criteria of systemic inflammatory response syndrome (a) core temperature higher than 38 °C or lower than 36 °C (b)respiratory rate above 20/min, or PCO2 below 32 mmHg (c) pulse rate above 90/min, and (d) white blood cell count greater than 12,000/μl or lower than < 4,000/μl or less than 10% of bands.

Exclusion Criteria:

Those who fulfilled one below:

• neutropenia (≤ 500 neutrophils/mm3)
• HIV infection, and
• patients or their relatives refused

Between May 2010 and March 2011, inpatients were included who were in the intensive care units (ICU) of the Department of Respiratory Disease, the Emergency Department, and the Department of Surgery of the Chinese People's Liberation Army General Hospital.