Markers di flogosi in chirurgia

1. Markers di flogosi in chirurgia Elisa Piva, Mario Plebani Dipartimento di Medicina di Laboratorio Azienda Ospedaliera – Università di Padova

2. INITIAL INJURY RESPONSE • Initial sterile “hit”(stress) as trauma or surgery includes activation of inflammation-responsive system • Patients with surgical injuries or trauma exhibit alterations in hemodynamic, metabolic, and immune responses that are largely orchestrated by activation of cytokine cascade. • Proinflammatory cytokine production in the intraoperative and early postoperative periods is initiated by macrophages and monocytes at the initial site of injury as part of the acute-phase response.

3. INDUCTION of SYSTEMIC RESPONSE No evidence of a systemic response with mild or modest injury after surgery. An insult of sufficient magnitude induces systemic response that encompass many features of a proinflammatory state. As the systemic inflammatory response continues, patient management and pathogen virulence (exogenous factors) assume a more prominent influence on the balance of systems activity. The interactions between endogenous and exogenous factors lead to uncertainty (gray area) over time about systems activity and overall responsiveness to secondary insults, such as infection.

4. Tumor necrosis factor-α Earliest and most potent mediators of subsequent host responses. Half-life is less than 20 minutes. The primary sources of TNF-α synthesis include monocytes/macrophages and T cells, which are abundant in the peritoneum and splanchnic tissues. Surgical or traumatic injuries to the abdominal viscera undoubtedly have profound influences on the generation of inflammatory mediators and homeostatic responses such as acute-phase protein production. IL-1b Half-life approximately 6 minutes. Local inflammatory mediator. Induces the classic inflammatory febrile response. Pain perception after surgery can be mediated by IL-1 by promoting the release of β-endorphins from the pituitary gland and increasing the number of central opioid like receptors. Interleukin-6 TNF-α and IL-1 are potent inducers of IL-6 production from virtually all cells and tissues, including the gut. Levels are detectable by 60 minutes, peak between 4 and 6 hours, and can persist for as long as 10 days. Circulating IL-6 levels appear to be proportional to the extent of tissue injury during an operation, more than to the duration of the surgical procedure itself. Evidences have demonstrated both a proinflammatory role and an antiinflammatory role for IL-6. [Tilg H et al, 1994] Cytokines

5. Increase of 10-100 times Increase of 2-10 times < 2 times Decrease C-reactive protein alfa1-Proteinaseinhibitor Caeruloplasmin alfa-antitrypsin Serum amyloid A alfa1-Acid glycoprotein C3 of complement Transferrin alfa1-Antichymotrypsin Alfa2-Antiplasmin alfa1-Lipoprotein Fibrinogen C1-inactivator Prealbumin Haptoglobin Albumin Pleiotropic actions of interleukin-6: induction of Acute-Phase Proteins

6. Changes in plasma CRP concentration after elective surgery General anesthesia Extradural blockade Changes in plasma concentrations of (a) CRP, and (b) IL-6 in patients undergoing total abdominal hysterectomy in two anesthesia groups Akintola, D. F. et al. Clin Chem 1997;43:845-847 Acute phase response of adult human hepatocytes stimulated with cytokines. (a) Dose-dependence; (b) time course Heinrich P.C. et a. Biochem J 1990; 265: 621-636

7. BIOMARKERS of SIRS

8. C-Reactive Protein • Discovered in 1930 by Tillet W. and Francis T. Term derived from the the reaction between the protein and C polysaccharide of the cell wall of the pneumococcus • 115,000 dalton, cyclic pentameric protein made of five protomers, each of 206 AA; synthesised in liver; IL-6 (and IL-1 and TNFa) stimulate synthesis via action on promoter (NF-kB) • Half-life of 19 h but clinical half-life after a single stimulus such a trauma or surgery is requiring several days until returning to baseline • Binds phosphocoline and phospholipid constituents of damaged cells, recognizes foreign pathogens • Activates the complement system, acts as “opsonine” • Induces inflammatory cytokines and tissue factor in monocytes, decreases the adhesion of PMN to endothelial cells, inhibits superoxide production, stimulates IL-1ra by mononuclear cells.Thus, its net effect is antiinflammatory The biology, utilization, and attenuation of C-reactiveprotein in cardiovascular disease: Part IAnnemarie Armani, MD,a and Richard C. Becker, MD,b New York, NY, and Durham, NCAmerican Heart JournalVolume 149, Number 6

9. ACUTE-PHASE RESPONSE in SURGERY

10. CRP CONCENTRATIONS AND CLINICAL APPLICATIONS • In surgical trauma markedly elevated levels of CRP are associated with the increased levels of IL-6 and neutrophil elastase[Hildebrandt U et al, 1999] • CRP is particularly useful in monitoring recovery from an operative procedure in uncomplicated cases [Fischer Cl et al,1976; Gonheim ATM et al, 1982; Shentag JJ et al,1984,]. • The increase of CRP is related to the extent of the surgical trauma, because laparoscopic performance of identical operating procedures is capable of reducing the acute phase response [Hildebrandt U et al, 2003] • CRP is elevated by surgery, trauma, malignancy, acute pancreatitis, myocardial infarction • Because of clinical half-life, serial CRP measurements often provide only a limited information to differentiate of critical conditions (SIRS vs Sepsis) [Vigushin, 1993] • For the diagnosis of sepsis the optimal cut-off value of CRP has yet to be established. Studies suggest as reasonable the value of 50-100 mg/L[Luzzani A et al, 2003] • CRP concentrations did not reflect the severity of sepsis and were not significantly different between survivor and nonsurvivor [Ciccarelli et al, 2008]

11. Characteristic Patterns of Changein Plasma Concentrations of Some Acute-Phase Proteins after a Moderate Inflammatory Stimulus

12. Serum Amyloid A Multifunctional proteins is an apolipoprotein that rapidly binds to high-density lipoprotein after their synthesis, influencing cholesterol metabolism during inflammatory states, causing adhesion and chemotaxis of phagocitic cells and lymphocyte. Overexpression caused by chronic inflammation produces damaging effects, e.g. amyloidosis and possibly arteriosclerosis. Regulated mainly by IL-1, TNF-a, IL-6 and glucocorticoids at the transcriptional and post-transcriptional levels. [Patewl et al, 1998; Gabay et al 1999] In postoperative septic shock CRP and SAA strongly correlated up to the fifth day of observation but were not good predictors of mortality in septic shock. [Ciccarelli et al 2008] C. M. Uhlar and A. S. Whitehead Eur. J. Biochem.,1999

13. SYSTEMIC INFLAMMATORY RESPONSE SYNDROME ( SIRS):DEFINIZIONE The systemic inflammatory response to a variety of severe clinical insults. The response is manifested by two or more of the following conditions: • temp above 38°C or below 36°C2. • heart rate >90 beats/min • respiratory rate >20/min or PaCO2 < 32 mm Hg4. • WBC: > 12,000 cells/mm3, < 4,000 cells/mm3 or immature (band) forms >10% (ACCP/SCCM; 1992 Consensus Statement on definitions. CritCare Med; 20:864)

14. INFLAMMATORY VARIABLES: WBC bands and IG BAND CELLS: wide variation in results both between individualsand laboratories Poor clinical utility IMMATURE GRANULOCYTES:automated immature granulocyte measurementsreflect a biologically and clinically relevantphenomenon but are not sensitive enough to be used asscreening assays for prediction of infection orbacteremia. Traditionalmarkers of infection, such asneutrophilia, lack sufficient sensitivityamong hospitalized patients to be ofvalue in distinguishing sepsis from noninfectiveinflammatory processes.(Cohen, Crit Care Med 2004 Vol. 32, No. 11 (Suppl.)

15. SYSTEMIC HOST RESPONSE: PROCALCITONIN Procalcitonin (PCT): the promoter of the PCT gene (Calc-1) has site for NFkb and AP-. The Calc-1 gene produces two different transcripts with very different functions. PCT mRNA is markedly stimulated in mononuclear cells by proinflammtory cytokines and LPS. PCT has been shown to inhnibit prostaglandin and thromboxane synthesis. In the course of a study on pediatric burn patients →increased serum PCT was shown to be a specific marker of sepsis in a pediatric population (Assicot et al, 1993; Lancet, 341:515)

16. PROCALCITONIN and SURGERY

17. PCT as a marker of infection following surgery • Serum PCT levels increase after uncomplicated surgery, reaching a peak level within 24 hours postoperatively. In the first 4 days levels may rise to < 10 ng/mL. Levels higher than this suggest infection. During the subsequent days values should fall to < 0.1 ng/mL. A PCT increase during this period strongly suggests bacterial infection • The dynamics of PCT levels, rather than absolute values, may be more important for identifying patients with infectious complications after surgery. • Intestinal surgery and major operations more often increase PCT, whereas it is normal in the majority of patients after minor and primarily aseptic surgery. PCT can thus be used postoperatively for diagnostic means only when the range of PCT concentrations during the normal course of a certain type of surgery is considered and concentrations are followed up. [Meisner M et al 1998] • PCT seems to be superior to CRP in discriminating infection after surgery. [Rothenburger M et al, 1999] • The diagnostic accuracy of PCT as a marker for postoperative complications is not yet sufficiently clarified [Boysen A et al 2005]

18. PROCALCITONIN • “Normal” values are in general < 0.5 ng/mL • Cut-off values for clinical decision-making are essential and must be context-specific for: • the clinical setting (eg primary care, emergency room, intensive care unit, post-operative or trauma patients) • the site and extent of the infection (eg RTI, endocarditis, meningitis, others) • co-morbidites (eg impaired pulmonary reserve, immunosuppression) • the clinical implications drawn (ie diagnosis, prognosis, antibiotic stewardship) For the majority of infections optimal cut-off ranges remain still to be determined in observational studies and validated in intervention studies

19. PCT and CRP for sepsis in critical patients after surgery or trauma Q values Summary receiver operating characteristics curves for procalcitonin (circle, solid line) and Creactive protein (triangle, dashed line); n =15 studies. Global diagnostic accuracy odds ratios for procalcitonin (PCT, circle, solid line) and C-reactive protein (CRP, triangle, dashed line); n=15 studies. OR, odds ratio; CI, confidence interval. Diagnostic accuracies were performed significantly better by PCT than CRP (Q* values for PCT=0.78, for CRP=0.71) Uzzan B et al. Crit Care Med 2006; 34: 1996-2003

20. DETERMINANTS of SIRS

21. Diagnostic criteria for SIRS/SEPSIS Infection, a documented or suspected, and some of the following: Metabolic variables Leukocytosis (WBC count >12 109/L) Leukopenia (WBC count < 4 109/L) Normal WBC count with >10% immature forms Hyperglycemia (plasma glucose >7.7 mmol/L) in the absence of diabetes Inflammatory variables Plasma C-reactive protein >2 SD above the normal value Plasma procalcitonin >2SD above the normal value Coagulation abnormalities (INR >1.5 or aPTT >60 secs) Organ dysfunction variables Acute oliguria (urine output <0.5 mL/kg/1hr) Creatinine increase >44.2 mmol/L Thrombocytopenia (platelet count <100 109L) Hyperbilirubinemia (plasma total bilirubin >70 mmol/L (4 mg/dL ) Tissue perfusion (haemodinamic)variables Hyperlactatemia (>1 mmol/L) 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference

22. Infections, SIRS and Sepsis MARKERS The ACCP/SCCM Consensus Conference Committee. The ACCP/SCCM Consensus Conference Committee.Chest. Chest. 1992;101:1644 1992;101:1644-1655.

23. Candidate biomarkers for the diagnosis of SIRS/ Sepsis

24. BIOCHEMICAL MARKERS in SIRS • Biochemical features in patients meeting the1992 SIRS criteria: • Interleukin(IL)-6 • Adrenomedullin • Soluble(s)CD14 • sELAM-1 • MIP-1a • Extracellular phospholipase A2

25. Considerations to be addressed in sepsis biomarker SPR, surface plasmon resonance; QCM, quartz crystal microgravimetry Carrigan SD et al. Clin Chem, 2004

26. a) CONCLUSIONS The manifestation of SIRS criteria is the common clinical phenotype of stressed surgical patients. It reflects the presence of consequential systemic inflammation and suggests incresing risk for complications and an adverse outcome. [Lowry, 2009]

27. SIRS/SEPSIS A single marker cannot reflect the entire spectrum of the disease in every biological aspects Measures, markers, and mediators: Toward a staging system for clinical sepsis. A Report of the Fifth Toronto Sepsis Roundtable,Toronto, Ontario, Canada, October 25–26, 2000 John C. Marshall, MD; Jean-Louis Vincent, MD, PhD; Mitchell P. Fink, MD; Deborah J. Cook, MD, MSc;Gordon Rubenfeld, MD, MPH; Debra Foster, BSc, RN; Charles J. Fisher Jr; Eugen Faist, MD; Konrad Reinhart, MD Crit Care Med 2003 Vol. 31, No. 5

28. BIOCHEMICAL MARKERS in SIRS Carrigan et al. Clin Chem, 2004

29. b) CONCLUSIONS Thus, a unique marker cannot differentiate sepsis from other causes of systemic inflammatory response syndrome; rather, markers are a part of a systematic evaluation that includes clinical examination . Sequential measurement of the inflammatory markers is likely to add more value for the diagnosis of infection than one-off measurements. Cohen, Crit Care Med 2004 Vol. 32, No. 11 (Suppl.)