Downloaded from http://gut.bmj.com/ on July 5, 2015 - Published by group.bmj.com
Gut Online First, published on July 3, 2015 as 10.1136/gutjnl-2015-310160
LETTER
Ascitic fluid TREM-1 for the diagnosis of spontaneous bacterial peritonitis We read with interest the study by Knoop et al1 who reported deleterious effects of antibiotics on the intestinal microflora. This observation should motivate the development of powerful tools for the diagnosis of infections to limit inappropriate antibiotic prescription. Spontaneous bacterial peritonitis (SBP) in patients with cirrhosis2 is a frequent life-threatening complication3 whose diagnosis is based on manual ascitic polymorphonuclear (PMN) count higher than 250 cells/μL.4 However, manual measurement of PMN count is operator dependent, makes quality control difficult and can delay the diagnosis.5 Recently, we have evaluated the validity and utility of ascitic fluid triggering
Table 1
PostScript
Description of the studied population
Characteristics
Test cohort
Validation cohort
Ascites samples (n) SBP, n (%) Male sex, n (%) Age (years), mean[range] Cause of cirrhosis, n (%) Alcohol Alcohol+viral hepatitis (B or C) Viral hepatitis Haemochromatosis Others Child–Pugh score, n (%) A B C Prothrombin time (%), median[range] Serum bilirubin (μmol/L), median[range] Albumin (g/L), median[range] Platelet count (109/L), median[range] Serum creatinine (μmol/L), median[range]
132 26 (20) 95 (72) 58 (11)
205 28 (14) 153 (75) 59 (11)
79 (60) 14 (11) 27 (21) 2 (1) 24 (18)
167 (81) 38 (18) 55 (27) – 21 (10)
5 (4) 39 (30) 88 (66) 51 [37–67] 57 [30–139] 26 [22–29] 107 [67–147] 97 [67–151]
6 (3) 83 (41) 116 (56) 59 [48–74] 40 [20–78] 29 [25–32] 116 [77–174] 78 [58–108]
Clinical and biological characteristics of the patients with cirrhosis were recorded on the day of paracentesis. SBP, spontaneous bacterial peritonitis.
Figure 1 (A and C) Ascitic fluid triggering receptors expressed on myeloid cells-1 (TREM-1) levels in two groups of patients, without or with spontaneous bacterial peritonitis (SBP), respectively. The line (----) represents the best threshold to distinguish SBP samples from those without SBP. (B and D) Receiver operating characteristic (ROC) curves for TREM-1 concentrations in ascitic fluid samples. (A and B) From the test study; (C and D) from the validation study. Gut Month 2015 Vol 0 No 0
1
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd (& BSG) under licence.
Downloaded from http://gut.bmj.com/ on July 5, 2015 - Published by group.bmj.com
PostScript receptors expressed on myeloid cells-1 (TREM-1) levels for the diagnosis of SBP. TREM-1 for triggering receptors expressed on myeloid cells-16 is a receptor expressed and released by innate inflammatory cells after exposure to bacteria membrane components.7 From February to October 2014, we prospectively included in a test cohort all consecutive patients older than 18 years with cirrhosis admitted to two departments of hepatology and one intensive care unit. Patients were admitted for new onset of ascites or for any complications of cirrhosis or underwent paracentesis in a day care setting. SBP was defined by a count of PMN >250/μL (with or without positive bacterial culture at 48 h).4 Exclusion criteria were limited to ascites not related to portal hypertension. Then, we used a validation cohort from three French hepatology departments. This validation cohort is a part of a larger biobank initially designed to evaluate cytokines in SBP (ClinicalTrials.gov: NCT01193426). Inclusion criteria were the same as in the test cohort. In both cohorts, measurements of ascitic TREM-1 concentrations were determined in duplicate using a polyclonal ELISA specific for human TREM-1 (R&D Systems)8 by a laboratory blinded to patients’ characteristics. A total of 132 ascites samples from 112 patients from the test cohort were analysed (table 1). Two patients were receiving curative antibiotic therapy before their paracentesis and 18 had prophylactic antibiotics. SBP was diagnosed in 26 samples (20%) and the bacterial ascitic fluid culture was positive in eight of them (31%). The median PMN count was 2256 [800–4968] cells/μL in the SBP samples and 3[0–11] cells/μL in the non-SBP samples ( p
Gut Online First, published on July 3, 2015 as 10.1136/gutjnl-2015-310160
LETTER
Ascitic fluid TREM-1 for the diagnosis of spontaneous bacterial peritonitis We read with interest the study by Knoop et al1 who reported deleterious effects of antibiotics on the intestinal microflora. This observation should motivate the development of powerful tools for the diagnosis of infections to limit inappropriate antibiotic prescription. Spontaneous bacterial peritonitis (SBP) in patients with cirrhosis2 is a frequent life-threatening complication3 whose diagnosis is based on manual ascitic polymorphonuclear (PMN) count higher than 250 cells/μL.4 However, manual measurement of PMN count is operator dependent, makes quality control difficult and can delay the diagnosis.5 Recently, we have evaluated the validity and utility of ascitic fluid triggering
Table 1
PostScript
Description of the studied population
Characteristics
Test cohort
Validation cohort
Ascites samples (n) SBP, n (%) Male sex, n (%) Age (years), mean[range] Cause of cirrhosis, n (%) Alcohol Alcohol+viral hepatitis (B or C) Viral hepatitis Haemochromatosis Others Child–Pugh score, n (%) A B C Prothrombin time (%), median[range] Serum bilirubin (μmol/L), median[range] Albumin (g/L), median[range] Platelet count (109/L), median[range] Serum creatinine (μmol/L), median[range]
132 26 (20) 95 (72) 58 (11)
205 28 (14) 153 (75) 59 (11)
79 (60) 14 (11) 27 (21) 2 (1) 24 (18)
167 (81) 38 (18) 55 (27) – 21 (10)
5 (4) 39 (30) 88 (66) 51 [37–67] 57 [30–139] 26 [22–29] 107 [67–147] 97 [67–151]
6 (3) 83 (41) 116 (56) 59 [48–74] 40 [20–78] 29 [25–32] 116 [77–174] 78 [58–108]
Clinical and biological characteristics of the patients with cirrhosis were recorded on the day of paracentesis. SBP, spontaneous bacterial peritonitis.
Figure 1 (A and C) Ascitic fluid triggering receptors expressed on myeloid cells-1 (TREM-1) levels in two groups of patients, without or with spontaneous bacterial peritonitis (SBP), respectively. The line (----) represents the best threshold to distinguish SBP samples from those without SBP. (B and D) Receiver operating characteristic (ROC) curves for TREM-1 concentrations in ascitic fluid samples. (A and B) From the test study; (C and D) from the validation study. Gut Month 2015 Vol 0 No 0
1
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd (& BSG) under licence.
Downloaded from http://gut.bmj.com/ on July 5, 2015 - Published by group.bmj.com
PostScript receptors expressed on myeloid cells-1 (TREM-1) levels for the diagnosis of SBP. TREM-1 for triggering receptors expressed on myeloid cells-16 is a receptor expressed and released by innate inflammatory cells after exposure to bacteria membrane components.7 From February to October 2014, we prospectively included in a test cohort all consecutive patients older than 18 years with cirrhosis admitted to two departments of hepatology and one intensive care unit. Patients were admitted for new onset of ascites or for any complications of cirrhosis or underwent paracentesis in a day care setting. SBP was defined by a count of PMN >250/μL (with or without positive bacterial culture at 48 h).4 Exclusion criteria were limited to ascites not related to portal hypertension. Then, we used a validation cohort from three French hepatology departments. This validation cohort is a part of a larger biobank initially designed to evaluate cytokines in SBP (ClinicalTrials.gov: NCT01193426). Inclusion criteria were the same as in the test cohort. In both cohorts, measurements of ascitic TREM-1 concentrations were determined in duplicate using a polyclonal ELISA specific for human TREM-1 (R&D Systems)8 by a laboratory blinded to patients’ characteristics. A total of 132 ascites samples from 112 patients from the test cohort were analysed (table 1). Two patients were receiving curative antibiotic therapy before their paracentesis and 18 had prophylactic antibiotics. SBP was diagnosed in 26 samples (20%) and the bacterial ascitic fluid culture was positive in eight of them (31%). The median PMN count was 2256 [800–4968] cells/μL in the SBP samples and 3[0–11] cells/μL in the non-SBP samples ( p
