SEPSIS BIOMARKERS. Dr.Saad Baher ElBadawi

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1 SEPSIS BIOMARKERS Dr.Saad Baher ElBadawi

2 Sepsis The Clinical term sepsis is characterized by a marked attack upon the host by pro inflammatory Cytokines that has been precipitated by infection. (Often manifested by two or more of the following: fever or hypothermia, tachypnea, tachycardia, leukocytosis or leukopenia) Temperature : above 38 C or below 36 C Heart : above 90 beat/min Respiratory Rate : above 20 breath /min or PaCO2 above 32 mmhg above WBC : above /cmm or below 4000/cmm or more than 10 % Bands

3 Systemic Inflammatory Response Syndrome Systemic inflammatory response Syndrome (SIRS) is the term given to patients who have two or more of the clinical symptoms noted in sepsis, although infection is not deemed to be present. Conditions include: Trauma, extensive surgery, heat stroke, pancreatitis, RDS, and burns. These conditions are frequently characterized by hyper secretion of proinflammatory cytokines.

4 Definitions Sepsis is defined as infection plus systemic manifestations of infection. Severe Sepsis: Is defined as sepsis plus sepsis induced organ dysfunction or tissue dysfunction tissue hypoperfusion Septic Shock: is defined as sepsis induced hypotension, persisting despite adequate fluid i ti it d t id resuscitation. Multiple Organ Dysfunction Syndrome: presence y p of altered organ function in an acutely ill patient such that homeostasis can not maintained without intervention. intervention.

5 Sepsis is a dynamic and complex syndrome. Sepsis is a dynamic and complex syndrome. Many markers have been implicated as playing a central and potentially harmful mediator role e.g. Endotoxin, Cytokines,, Chemokines, Prostaglandins, Oxygen free radicals, soluble Receptors.

6 Lactate Is lactate an early warning sign in sepsis patients? YES: The prognostic value of raised blood lactate levels is well established in septic shock patients(1) Blood lactate levels have greater prognostic value than oxygen derived variables in predicting the outcome in human septic shock(2) SSC Guidelines 2008: Begin resuscitation immediately in patients with hypotension or elevated serum lactate 4mmol/L SSC Sepsis Bundles 2004 Serum lactate must be available in your institution with rapid turnaround time (within minutes) to effectively treat severely septic patients. Probability bilit of survival ldeclines with ithincreasing i blood lactate level(1) 1 Weil MH, Afifi AA, Experimental and clinical studies on lactate and pyruvate as indicators of the severity of acute circulatory failure (shock), Circulation 1970; 41: Bakker J, et al., Blood lactate levels are superior to oxygen derived variables in predicting outcome in human septic shock, Chest 1991; 99:

7 Mortality Sepsis occurs in 5 different severities (clinical entities) mortality increases ith it with severity(1) 1 Levy MM et al., 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference, Intensive Care Med 2003; 29:

8 Death Rates Severe sepsis kills more persons than the most frequent cancers. Disease Number of deaths Sever sepsis 215,000 Acute myocardial infarction 193,000 Lung cancer 156,000 Colon cancer 57,000 Breast cancer 42,000 Source :Eli Lilly company website y DATAMONITOR

9 Incidence Sepsis incidence is increasing USA 3.8 Mio SIRS cases new cases of severe sepsis in 2000 (mortality rate 20-50%) cases of septic shock in 1997 (mortality rate 40-60%)

10 Sepsis Pathophysiology sepsis at a glance

11 Inflammatory Triggers(s) (burns, endotoxin, infection, injury, etc.) Activation of host Leukocytes, Lymphocytes, Endothelial cells, and various Parenchymal cells (via CD14, toll-like receptors, AP-1, NF-kB, etc.) Coagulation & complement cascade activation Cytokines and related factors Humoral Response Repertoire Acute Phase Proteins Stress hormones Hormokins Intracellular factors Immuno regulatory Pro inflammatory IFN MIF Adhesion molecules IL 4 IL 2 IL 1ß Chemokines IL 6 IL 4 IL 6 Elastase IL 10 IL 5 IL 8 Endothelin IL 11 IL 11 IL 12 Growth factors IL 13 IL 15 IL 1 decoy receptors IL ra IL 18 LTs Leptin NO Proteases NO PAF RANTES TNFr PGs ROI TGF ß TNF TBs Anti inflammatory 1 -acid glycoprotein Angiotensinogen CRP Ferritin Fibronectin Haptoglobin Lipopolysaccharide Phospholipase 2 PTX 3 Serum amyloid A ACTH AVP Catecholamines Cortisol Endorphins GH Histamine Prolactin ADM CGRP CTpr IL-6 Leptin MIF PCT Heat shock proteins HMG-1 NO Local Inflammation (calor, dolor, rubor, tumor, functio laesa) Systemic Inflammation ( heart rate, resp rate, body temp, white blood cell count) Recovery Decompensaion (e.g. sever sepsis, sepic shock) MOF Death

12 SEPSIS BIOMARKERS

13 SEPSIS BIOMARKERS 1. Cytokine/Chemokine biomarkers 2. Cell marker biomarkers 3. Receptor biomarkers 4. Coagulation biomarkers 5. Biomarkers related to vascular endothelial damage 6. Biomarkers related to vasodilation 7. Biomarkers of organ dysfunction of organ 8. Acute phase protein biomarkers 9. Other biomarkers

14 1. Cytokine/chemokine biomarkers

15 IL 6 Biochemistry Summary 184 amino acids glyco protein and has a molecular weight of about 26 kd Released by many cells. Multiple biological actions on different types of target cells via receptors and gp130 Substantial impact on the immune system, hematopoesis, and inflammation. Longest half life of the pro inflammatory mediators in the systemic circulation Activation time: very short Half life time: about 1 hour IL 6 triggers the production and release of CRP in the liver IL 6 6 triggers to a certain extent Procalcitonin to extent Early and sensitive alarm marker for (systemic) inflammation and sepsis and neonatal sepsis.

16 Membrane expressed receptor ( mil6r) are only present on few cell types Glycoprotein 130 (gp130) is the signal transducing subunit and ubiquitary expressed. Soluble IL6 receptor (sil6r) helps that IL6 can interact with cells without own mil6 by forming complex with gp130

17 IL 6 and Severity of Disease IL 6 values increase steadily with severity of the steadily severity the disease.

18 IL 6 and Severity of Disease IL 6 6 (pg/ml) 7 pg/ml * Median Mean Min Max N SIRS Sepsis Severe Sepsis Septic Shock

19 Interleukin 10 (IL 10) is known to have anti inflammatory activity. Interleukin 10 (IL 10) is a Type II cytokine and the 10) i II t th founding member of a family of cytokines that include IL IL 19 19, IL IL 20 20, IL IL 22 22, IL IL 24 24, IL IL 26 26, IL IL 28 28, and IL 29 (1). All of these cytokines activate Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways.

20 The binding of IL IL to the receptor complex the complex activates the Janus tyrosine kinases, JAK1 and Tyk2, associated with IL 10R1 and IL 10R2, respectively, to phosphorylate the cytoplasmic tails of the receptors. This results in the recruitment of STAT3 to the IL 10R1. t t th The homodimerization of STAT3 results in its release from the receptor and translocation of receptor and translocation of the STAT homodimer into the nucleus, where it binds to STAT STAT binding binding elements in the promoters the of various genes.

21 The IL 10 receptor and a simplified version of signaling from this receptor The functional receptor complex is composed of two subunits each of IL 10 R1 and IL 10R2. The Janus tyrosine kinases JAK1 and Tyk2 associate with the cytoplasmic tails of the receptor and phosphorylate tyrosine residues in IL 10R1, to which STAT3 is recruited. STAT3 homodimers translocate into the nucleus and bind to STAT elements in several immune several immune response genes, including IL 10 itself and the SOCS genes.

22 2. Cell marker biomarkers

23 Objective: The goal was to determine the utility of neutrophil CD 64 as a diagnostic marker for sepsis in neonates. Conclusions: Neutrophil CD 64 is a highly sensitive marker for neonatal sepsis. t i Prospective studies incorporating CD 64 into a sepsis scoring system are warranted.

24 Neutrophil CD11b and CD64 appear to be promising markers for diagnosis of early and late onset infections. CD11b is normally expressed at a very low concentration on the surface of non activated neutrophils. There is a 2 4 fold increase in neutrophil CD11b expression in infants with blood culture positive sepsis, sepsis similartothatseen similar to that seen in adults inadults with blood culture positive sepsis. The sensitivity and specificity of CD11b for diagnosing early onset neonatal sepsis are % and 100% respectively.

25 3. Receptor biomarkers

26 MAMMALIAN TOLL LIKE RECEPTORS

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29 Triggering receptor expressed on myeloid cells like (TREM like) transcript 1 (TLT 1), a type 1 single Igdomain orphan receptor specific to platelet and megakaryocyte granules, relocates to the platelet surfaceupon platelet stimulation. We found here that patients diagnosed with sepsis, in contrast to healthy individuals,had substantial levels of soluble TLT 1 (stlt 1) in their plasma that correlated with the presence of disseminated the intravascular coagulation. stlt 1 bound to fibrinogen and augmented platelet aggregation in vitro.

30 4. Coagulation biomarkers

31 5. Biomarkers related to vascular endothelial damage

32 6. Biomarkers related to vasodilation

33 7. Biomarkers of organ dysfunction

34 Protein S100 S100 A1 und B is predominantly found in astrocytes and Schwann cells It can be detected in the systemic circulation when the BBB opens Urban & Fischer 2003 Roche Lexikon Medizin S100 S100

35 Protein S100 Clinical Indications Three distinct clinical indications clinical indications Exclusion of minor traumatic brain injury (MTBI) Monitoring primary/secondary brain injury in severe traumatic brain injury ti i i intracranial hemorrhage e.g. after severe stroke or subarachnoidal hemorrhage sepsis patients Monitoring melanoma patients stage III and IV

36 OBJECTIVE: To determine whether known serum markers of neurologic injury are increased in children with septic shock. MEASUREMENTS AND MAIN RESULTS: AND MAIN RESULTS: Children with septic shock demonstrated increased serum Protein S100beta and NSE compared with controls Serum. In cohort 2, urine of four patients demonstrated measurable Protein S100beta levels, CONCLUSIONS: Markers of neurologic injuries S100beta are increased in children with septic shock. This may indicate subclinical injuries that are either transient or permanent. Studies that correlate the long term neurologic outcome of children with these markers are needed to identify children at risk for neurologic injuries risk for neurologic injuries from septic shock

37 8. Acute phase protein biomarkers

38 BACKGROUND AND OBJECTIVE: C reactive reactive protein (CRP) has been considered a marker considered a for infection and an aid for diagnosing sepsis. We analyze the relation of CRP to infection and outcome in intensive care units (ICU) patients. CONCLUSIONS: CRP level on admission is an useful an marker for early infection but not for outcome in critically ill patients admitted to the ICU.

39 Late onset sepsis (LOS) (i.e., sepsis in a neonate after 72 hours of life) is associated with high mortality and significantly prolonged antibiotic exposure and hospital stay in neonates admitted to intensive care units (ICU). itt d t i t i it Primary efficacy endpoint was the duration of antimicrobial therapy. Secondary efficacy endpoints were the proportion of relapsing sepsis within 72 hours of antibiotic withdrawal sepsis hours antibiotic withdrawal and the overall mortality rate. Length of antimicrobial treatment of LOS was significantly treatment LOS significantly shorter during the second study period (16 days vs. 9 days, p<0.001). Secondary efficacy endpoints showed similar rates of relapsing sepsis and overall mortality in both time periods.

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41 9. Other biomarkers

42 PRINCIPLE: Serum lactate is a potentially useful biomarker to risk stratify patients with severe sepsis; however, it is plausible that elevated serum lactate is simply a manifestation of clinically apparent organ dysfunction and/or shock (i.e., refractory hypotension). OBJECTIVE: To test whether the association between initial serum lactate level and mortality in patients presenting to the emergency level and in presenting to the emergency department (ED) with severe sepsis is independent of organ dysfunction and shock. CONCLUSIONS: Initial serum lactate was associated with mortality independent of clinically apparent organ dysfunction and shock in patients admitted to the ED with severe sepsis. Both intermediate and high serum lactate levels were independently associated with mortality.

43 9. Other biomarkers (cont.)

44 Biomarkers that have been assessed for use in the diagnosis of sepsis

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46 Procalcitonin and its constituent peptides in normal serum, all of which are found at the indicated low concentrations in the blood of normal humans CT:CCP-I (0.17 fmol.ml -1 ) NProCT Immature CT CCP-I (0.19 fmol.ml -1 ) Mature CT (1.84 fmol.ml -1 ) Procalcitonin NProCT (4.15 fmol.ml -1 ) CCP-I (3.17 fmol.ml -1 )

47 The primary pathophysiological trigger for the increase of serum ProCT is serum is infection (whether exogenous in origin or via endogenous translocation of bacterial toxins across the gut wall or other epithelial barriers). Infection results li l i ti lt in the appearance in the circulation of LPS, although it is likely that other constituents of microorganisms also are offenders. Soon thereafter, there is a secondary release of the putative principal pro principal pro inflammatory inflammatory and antiand anti inflammatory cytokine messengers.

48 Current data indicate that mediators such as TNFa that such as (as well as IL 1b and IL 6) comprise the specific proximate stimuli to hyperprocalcitonaemia. Cytokines appear to have a recurrent but short lived duration and their erratic fluctuations differ markedly from the long term persistence of hyperprocalcitonaemia, a late and long lasting marker and mediator. and mediator

49 LPS, LTA, etc. Parenchymal Immune cells cells Pro-inflammatory cytokines Procalcitonin Illustrative sequence of events by which endotoxin (lipopolysaccharide) from Gram p y negative bacteria or other bacterial products, such as lipotechoic acid (LTA) from Gram positive bacteria (Ryu et al., 2009), interact with immune cells via toll like receptors (TLRs) to initiate a pro inflammatory cytokine response that induces the systemic hypersecretion of procalcitonin (ProCT) from parenchymal cells. In turn, in a feedback manner, the blood p, cell production of these same cytokines may further augment the local levels of ProCT.

50 TNFa, a potent stimulant of ProCT production (Whang et al., 2000; Redl et al., 2001) may, along with other cytokines, further reinforce the already high ProCT reinforce the high levels of sepsis in a self perpetuating cascade fashion. ProCT itself is not primarily an initial pro inflammatory stimulus. Instead, it is a potent amplifier of the inflammatory cascade.

51 Procalcitonin Guided Antibiotic Usage

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