The role of procalcitonin and IL-6 in discriminating between septic and non-septic causes of ALI/ARDS: a prospective observational study

Abstract

Early plasma - but not BALF - PCT concentrations can discriminate between septic and non-septic ARDS causes and are associated with the severity of multiple organ dysfunction syndrome in septic ARDS patients. However, neither plasma or BALF IL-6 levels nor BALF PCT levels carry any prognostic potential. A single plasma PCT value higher than 0.815 ng/mL makes a non-septic cause of ARDS highly unlikely.

Serial Inflammatory Biomarkers of the Severity, Course and Outcome of Late Onset Acute Respiratory Distress Syndrome in Critically Ill Patients With or At Risk for the Syndrome After New-Onset Fever

“…Furthermore, ANG2 predicted mortality independently of the SAPS II score and sepsis, in agreement with most, 12,19,20,22 but not with another, small study. 15 IL6 levels, which may reflect inflammation, were not predictive for 28-day mortality, in contrast to other studies. 14,15,[28][29][30][31] The value and limitations of IL6 to diagnose and monitor ARDS severity, resulting from community-acquired pneumonia, for instance, have been described before.…”

“…13 Because of clinical classification problems, amongst others, there is an active search for biomarkers that may accurately predict the development or presence of alveolocapillary inflammation of ARDS and would help in risk stratification and management in future studies. [14][15][16] We and others previously described that circulating angiopoietin-2, possibly derived from the pulmonary vessel wall, is associated with alveolocapillary permeability, development of clinical ARDS, positive fluid balance and mortality in the critically ill sepsis or trauma patients, even though sepsis and trauma may predispose to different ARDS phenotypes. 12,13,16,[17][18][19][20][21][22][23][24] The biomarker value for ARDS of alternative molecules such as pentraxin-3, a pro-inflammatory acute phase mediator, [25][26][27] interleukin-6, a cytokine with both pro-and anti-inflammatory properties, [14][15][16]19,25,[28][29][30][31][32][33] procalcitonin, a marker of inflammation, 15,16,34,35 and midregional pro-adrenomedullin, a stable fragment of adrenomedullin with immune modulating, metabolic and vasodilator actions and prognostic properties in pneumonia and sepsis, [36][37][38][39] remains unclear up till now.…”

“…The literature on foregoing biomarkers reported on less than 60 patients 13,17,20,26,28,32,35 or on only one single marker or clinical classification system for ARDS. 14,15,[17][18][19][20][21][22][23][24]26,28,[31][32][33][34][35] Moreover, many studies were cross-sectional. 11,12,14,15,[17][18][19]21,23,24,[30][31][32][33][34][35][36][37][38][39] Since these studies focused mostly on early ARDS development or its outcome, the value of biomarkers in reflecting severity and course of late onset ARDS regardless of risk factors is largely unknown.…”

“…The hypothesis was that biomarkers directly associated with inflammation, such as angiopoietin-2, interleukin-6 and procalcitonin would be more accurate than those indirectly associated with inflammation, such as pentraxin-3 and proadrenomedullin, independent of underlying ARDS risk factor. 13,15,16,18,29…”

Alveolar neopterin, procalcitonin, and IL-6 in relation to serum levels and severity of lung injury in ARDS

“…To the Editor, Tsantes et al evaluated plasma and bronchoalveolar lavage fluid (BALF) procalcitonin (PCT) and interleukin-6 (IL-6) in discriminating septic from non-septic causes of acute respiratory distress syndrome (ARDS) [1]. They concluded that early plasma, but not BALF-PCT concentrations, can help distinguish between septic and nonseptic ARDS causes and are associated with the severity of multiple organ dysfunction syndrome in septic ARDS patients.…”