Frank H Wians Jr PhD MTASCP MASCP DABCC FACB Professor of Pathology Texas Tech University of the Health Sciences Center El Paso and the Paul L Foster School of Medicine Technical Director Clinical Chemistry University Medical Center UMC El Paso ID: 730119
Download Presentation The PPT/PDF document "Acute Phase Proteins in the Management o..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Acute Phase Proteins in the Management of Inflammatory Diseases
Frank H. Wians, Jr., PhD, MT(ASCP), MASCP, DABCC, FACBProfessor of PathologyTexas Tech University of the Health Sciences Center El Pasoand thePaul L. Foster School of MedicineTechnical Director, Clinical Chemistry, University Medical Center (UMC) El PasoMedical Director, UMC Far East and West Clinic LaboratoriesLt Col (Ret), USAF, Biomedical Sciences CorpsRole in Air Force Coronary Atherosclerosis Prevention Study (AFCAPS)Editor-in-Chief, Lab Medicine, 2004-2011frank.wians@ttuhsc.edu
2018 Texas Association for Clinical Laboratory ScienceThursday, 22 Mar 2018Wyndham, El Paso AirportSlide2
DisclosuresDisclosures
NoneSlide3
Outline
History of acute phase proteins (APPs)Definition of APPExamples of human APPsFunction of APP responseAPPs as targets for therapyStatin Rx to reduce risk for CVDSummarySlide4
Discovery of “Precipitins” Reactive With Somatic “C” Fraction of Pneumococcus
1930 – Tillett and Francis demonstrated that the sera of patients during the acute phase of pneumococcal pneumonia reacted with pneumococcal C-polysaccharide (CPS) fractions (C-Fractions) resulting in an observable precipitate at high titers of C-Fraction, especially, in the early stages of pneumococcal pneumonia (J Exp Med. 1930;52:561-71).The CPS precipitins named, “C-reactive protein” (CRP),” after discovery by Macleod and Avery in 1941 of their calcium-dependent precipitation of the pneumococcal C-polysaccharide (CPS).Specific ligand for CRP binding to CPS was identified as phosphorylcholine (PC) by Tomasz in 1967.Slide5
History of APPs
1965 - Gottschlich and Edelman report structure of CRP as mainly pentamers1977 - Osmand et al. identify structure of CRP as 5 identical, 23 kDa subunits in a planar pentameric arrangement (pentraxin)Pentraxins - an evolutionary conserved family of proteins (pattern recognition receptors) characterized by containing a pentraxin protein domain and are involved in acute immunological responses.2002 – Wang et al. report 2 additional CRP structures: small globulin- and fibril-like structuresSince the identification of the first APP (CRP) in 1930, the list of APPs has grown to >50Slide6
Definition of APP
A protein whose plasma concentration increases (“positive” APP) or decreases (“negative” APP) by at least 25% during inflammatory disorders.Inflammation - a non-specific, localized reaction to combat the multiple deleterious effects of the pathogenic agent eliciting the inflammatory response (a self defense mechanism).Slide7
Types of APPs and Some Examples
Positive APPsCRPC3/C4FibrinogenCeruloplasminHaptoglobin (HPT)Hemopexin (HPX)FerritinProcalcitonin (PCT) – one of the relatively newer acute phase proteins/markers (a topic for another lecture)Negative APPsAlbuminTransferrinPrealbumin (transthyretin)Slide8
Conditions Leading to Increased Plasma Concentrations of APPs
Large increaseInfection (sepsis)TraumaSurgeryBurnsTissue infarctionImmunologically-mediated and crystal-induced inflammatory conditionsAdvanced cancerModerate changesStrenuous exerciseHeatstrokeChildbirthSmall changesPsychological stressSeveral psychiatric illnessesSlide9
Synthesis of APPs
Produced by hepatocytesMagnitude of the increase in APPs during an acute phase reaction variesCeruloplasmin increases by ~50%CRP & Amyloid A* increase by 1000-foldTime-course of change in [APP] varies*Serum amyloid A (SAA) - an acute phase reactant whose level in the blood increases in response to various insults. It is expressed in the liver and local production of SAA proteins occur in histologically normal, atherosclerotic, Alzheimer, inflammatory, and tumor tissues, and it plays an important role in various physiological and pathological processes, including inflammation, atherosclerosis, thrombosis, AA-amyloidosis, rheumatoid arthritis, and neoplasia. Slide10
Time-Course of Change in Plasma Concentration of Some APPs After An Inflammatory Stimulus
Source: Gabay C, Kushner I. NEJM 1999;340:449-454Slide11
Human APPs
Source: Gabay C, Kushner I. NEJM 1999;340:449-454Increase
Decrease
Comprises 75-80% of normal plasma colloid oncotic pressure and 50% of protein content.
↓
Albumin - no longer sustain sufficient colloid osmotic pressure (
↓
) to counterbalance hydrostatic pressure
,
edema
develops.
Causes of Edema
Reduced ability to synthesize adequate amounts of albuminSlide12
Partial List of Inflammation-Associated Proteins, Enzymes, Enzyme Inhibitors, and Transmembrane Mediator of Inflammation
Nature has invested considerable resources in creating a wide variety of molecules involved in one or more components of the inflammatory process/response.Slide13
Systemic Reponses to Inflammation
Large number of changes, distant from the site or sites of inflammation, and involving many organ systems accompany inflammationThese changes referred to as “acute phase response” (APR)Term APR a misnomer: same changes occur in “chronic” inflammatory disordersSlide14
Pathophysiological changes of thesystemic inflammatory response
Neuroendocrine changesFever, somnolence, fatigue and anorexiaIncreased adrenal secretion of cortisol, adrenaline and glucagonHematopoietic changesAnemia LeucocytosisThrombocytosisMetabolic changesLoss of muscle and negative nitrogen balanceIncreased lipolysisTrace metal sequestrationDiuresis
Hepatic changesIncreased blood flowIncreased acute phase protein productionSlide15
Pathways for Initiation of Inflammation
Source: Cecil Textbook of Medicine 2004Slide16
SIRS (Systemic Inflammatory Response Syndrome)
The systemic response to a wide range of stressorsTwo or more of the following must be present:Temperature >38°C (100.4°) or <36°C (96.8°F).Heart rate >90 beats/min.Respiratory rate >20 breaths/min or PaCO2 <32 mmHg.White blood cells > 12,000 cells/mL or < 4,000 cells/mL or >10% immature (band) forms.These changes should represent acute alterations from baseline in the absence of other known causes for the abnormalities.
American College of Chest Physicians/Society of Critical Care Medicine Consensus.
Crit Care Med. 1992;20:864-874.Slide17
Overview of Acute Phase Response (APR)
SuccessfulYesNo
Homeostasis Restored
Organ Dysfunction
The goal of the APR is to restore homeostasis and prevent death!
A choreographed response involving migration of leukocytes in response to chemical signals
(
chemotaxis
)
; extension of pseudopodia by leukocytes that allows them to pass through capillary walls (
emigration
); expression of adhesion molecules that slow emigration of leukocytes and promote their movement (
margination
) to and alignment along the periphery of blood vessels (
pavementing
); and, finally,
the neutrophils and macrophages engulf and degrade the bacteria and cellular debris (
phagocytosis
).Slide18
Acute Phase Phenomena
Increase in +APPsDecrease in –APPsMultiple organ system changesNeuroendocrineHematopoieticMetabolicHepaticNonprotein plasma constituentsSlide19
Multiple Organ System Changes During APR
Source: Gabay C, Kushner I. NEJM 1999;340:449-454Slide20
Function/Effects of the APR
Adaptive (to a noxious stimulus)Anti-inflammatoryAntioxidant properties of HPT and HPXPro-inflammatory cytokine - a cytokine (or type of signally molecule) that is excreted from immune cells and certain other cell types that promotes inflammation. Examples include:Interleukin-1 (IL-1), 6-, -12, and -18Tumor necrosis factor (TNF)Interferon gamma (IFN-gamma)Granulocyte-macrophage colony stimulating factor (GMCSF)Pro-inflammatory cytokines are released that promote inflammation and trigger a counter-regulatory response by anti-inflammatory biomarkers.Complement activation in immunity and opsonization (process of opsonin binding to infectious agents to make them more attractive to phagocytes for elimination).Slide21
Regulation of APP Changes
Cytokines/cytokine receptorsCentral role of interleukins (ILs)Transcriptional regulation of expression of genes for APPsPost-translational mechanismsGlycosylation of plasma proteinsAlterations in oligosaccharide branchingIncrease sialylation of orosomucoidDecreased galactosylation of IgGSecretion of APPsSecretion of CRP greatly increased during APRSlide22
Regulation of APP Changes
Central role of cytokines/interleukins (ILs) and growth factorsIL-1, -6 (chief stimulator of the production of most APPs), -10, -13, -15, -17, -18TNF (tumor necrosis factor alpha)VEGF (vascular endothelial growth factor)TGF- (transforming growth factor-beta)FGF (fibroblast growth factor)Produced by a variety of cell types, especially macrophages and monocytes at sites of inflammationSlide23
IL-6
Role in stimulating APPs depends onNature of the inflammatory stimulusSite of the inflammatory responseAPR in IL-6 knockout miceInhibited when turpentine injectedNormal when bacterial lipopolysaccharide injectedCytokines other than IL-6 are capable of stimulating the production of APPsPlasma IL-6 concentrations respond faster than CRP to APR stimuli, but routine measurements of cytokines and their receptors limited by:Short half-lifeBlocking factors in plasmaLimited assay availability
Higher costAbsence of assay standardizationSlide24
Most Widely Used Laboratory Indicators of APR
ESRValues change slowly with worsening or improving diseaseResults increase steadily with increasing ageCRPPlasma levels change rapidly with worsening or improving diseaseConcentration not affected by age80-85% of patients with [CRP] > 100 mg/L have bacterial infections[hsCRP] in the highest quartile provides 3x the risk for a future cardiovascular event than a [hsCRP] in the lowest quartileSlide25
Measurement of CRP by Immuno-
nephelometry: rCRP versus hsCRPParameterType of CRP assay
rCRP
hsCRP
Sample vol, uL
40
40
Solid phase
PSP
PSP
Capture hCRP-Ab
Mcl
Mcl
Calibration points
6
6
MDC, mg/L
3.5
0.175
Analytical range, mg/L
3.5-110
0.175-5.5
Interassay imprecision, %CV
2.6-5.7
a
2.1-3.8
b
Reference interval, mg/L
≤
5
≤
3
a
At
[CRP] of 14-56 mg/L.
b
At
[CRP] of 0.5-2.1 mg/L.
rCRP
, regular C-reactive protein;
hsCRP
, high sensitivity CRP; PSP, polystyrene particles;
Mcl
, monoclonal; MDC, minimum detectable concentration;
Ab
, antibodySlide26
Why Study the Role of APPs in Atherosclerosis? Heart Disease Still the No. 1 Cause of Death in the U.S.
Source: National Vital Statistics Reports, Vol. 66, No. 6, November 27, 2017 Slide27
Central Role for Inflammation in Atherosclerotic Disease Process
Current evidence supports role for inflammation inInitiation and progression of plaque lesionPlaque ruptureThrombotic complications of CVDSeveral biomarkers linked to inflammation and atherogenesisRef: Ballantyne C, Nambi V. Atherosclerosis Suppl 2005;6:21-29Slide28
Atherosclerosis and Statin Therapy: a Prototype Disease-R
x Combination for the Role of APPs In Inflammatory DisordersSlide29
Hypotheses
If atherosclerosis is an inflammatory disease and +APPs are increased in inflammatory diseases, APPs might be increased during atherogenesis.If the levels of APPs change with therapy, they might be useful in monitoring response to therapy or assessing risk of future cardiovascular events.Slide30
Biomarkers Linked to Inflammation,
Atherogenesis, and Response to Statin TherapyCRPAdiponectinMonocyte chemoattractant protein-1 (MCP-1)CD40 ligand (CD40L)Lipoprotein-associated phospholipase A2 (Lp-PLA2)Ballantyne CM, Nambi V. Atherosclerosis Suppl 2005;6:21-29Slide31
Biomarkers Linked to Inflammation,
Atherogenesis, and Response to Statin TherapyBiomarkerStructure
Site of synthesis
Biological actions
CRP/
hsCRP
Pentameric
ring-, small globulin-, and fibril-like forms
Hepatocytes
Recognize some foreign pathogens and PL components of damaged cells; induce inflammatory cytokines and monocyte-derived tissue factor (TF)
Adiponectin
244-aa
Adipocytes
Glucose/insulin/FA metab; inflammation
MCP-1
CC chemokine
Endothelial and SM cells
Mediates monocyte recruitment and entry into vessel walls at sites of CAD
sCD40L
Transmembrane prot related to TNFalpha
Endothelial, SM, macrophages, T-
lymphs
, platelets
Plaque progression and instability during development of CAD
Lp-PLA
2
Enzyme distinct from secretory PLA
2
Secreted by monos, macrophages, T-lymphs, mast cells
Hydrolyzes
oxPLs
to
lysoPC
which upregulates adhesion molecule expressionSlide32
Quartile of
hsCRP versus Relative Risk of Peripheral Arterial Disease (PAD)Slide33
Comparison of Relative Risk for a Future CV Event Based on Abnormal Values for Several Biomarkers
Relative RiskHigher risk when increased hsCRP present with increased TC/HDLC ratioSlide34
hsCRP
Adds to the RR Information Providedby the TC/HDLC RatioSlide35
Statins: Generic and Brand Names
Are all statins created equal?Slide36
From Framingham Study to Statin Drug Rx
Dawber TR, Meadors GF, Moore FE, Jr.: Epidemiological approaches to heart disease: the Framingham Study. Am J Public Health 1951; 41(3):279-286.In addition to lowering cholesterol levels, statins also reduce inflammation, which could be another mechanism by which statins beneficially affect atherosclerosis. This reduction of inflammation does not depend on statins' ability to reduce cholesterol. Furthermore, these anti-inflammatory effects can be seen as early as two weeks after starting statins.Slide37
Statins: Mechanism of ActionSlide38
hsCRP
PV Additive to FE of 10-Yr Risk for1st CV Event and [LDL-C]10-y risk of 1st CV event increases as CRP and LDL-C levels increase!Slide39
ANDROMEDA Study
A raNdomised Double blind double-dummy, multicentre, phase IIIb, parallel-group study to compare the efficacy and safety of Rosuvastatin (10 mg and 20 mg), and atOrvastatin (10 Mg and 20 mg) in patiEnts with type 2 DiAbetes mellitus (ANDROMEDA) Slide40
Effect of Statin R
x in ANDROMEDA StudyRosuvastatin provided a significantly better response than atorvastatin in lowering LDL-C levels and no significant difference in lowering CRP levels at either 10 or 20 mg doses at 8 or 16 weeks.Slide41
Atherosclerosis Risk in Communities (ARIC) Study
12,819 men and women free of CHD at baseline6 year F/UFindingsBoth Lp-PLA2 and CRP associated with increased risk for incident CHD after adjustment for age, race, and genderBoth Lp-PLA2 and CRP associated with increased risk for strokeSlide42
Association of Lp-PLA
2 and CRP With Incident CHD in Patients With [LDL-C] < 130 mg/dLSlide43
Association of Lp-PLA
2 and hsCRP With StrokeHazard Ratio (HR) – a measure of an effect of an intervention (or abnormal test(s) results) on an outcome of interest over timeInterpretation: At any time point, nearly 9 times as many patients with hsCRP levels >3 mg/L and Lp-PLA2
levels ≥ 422 ug/L experience a stroke than individuals with low levels of both (HR = 1.00) of these markers of inflammation. Slide44
Additional Studies on CRP
CRP capable of predictingDeath among high-risk patients with CVDIschemic complications among patients with stable anginaRecurrent coronary events among those with known CAD such as MI or anginaSlide45
Effect of Statins on Various Markers of Inflammation
APP
Effect of various statins, % change in [APP] compared to baseline or placebo
Prava
Atorva
Rosuva
Simva
Fluva
Lova
CRP
14
34
a
40
a
14.8
c
Adiponectin
MCP-1
7
12.5*
sCD40L
b
Lp-PLA
2
29-43*
25*
a
No
significant difference between these 2 groups (statin treated vs baseline or placebo).
b
In
patients with high levels of sCD40L, risk for recurrent CV events 48% lower in
atorvastatin
-treated patients.
c
AFCAPS
/TEXCAPS. *, p-value < 0.05;
, decrease;
, no change.
MCP-1
, monocyte chemoattractant protein-1;
sCD40L
, soluble CD40 ligand;
Lp-PLA
2
, lipoprotein-associated phospholipase A
2
, Slide46
Summary
Statins provide clinical benefit in reducing both CHD events and stroke, even in patients without elevated LDL-CThis benefit may be due to effects beyond changes in plasma lipoproteins, such as effects on markers of inflammationSlide47
Thank You For Your Attention!
My granddaughters, Valeria Alexandra Wians (Hispanic-American, left, now 10 yo) and Randihma Ryou Wians (Japanese-American, right, now 9 yo), from 2 of my 3 sons,
thank you as well.
This is what can happen when East meets West!
Jason and Maki Wians after their traditional Japanese wedding