Assessment of AirwayInflammation

Assoc. Prof. Bülent Karadağ, MD

Marmara University, Div. of Pediatric Pulmonology

Asthma• Asthma is a chronic disease

characterized by recurrent episodes of:–wheezing, –shortness of breath, and –cough 2° to reversible airflow

obstruction• Bronchial hyperresponsiveness &• Airway inflammation are hallmarks of

asthma.

Before 10 min afterallergen

challenge

Bronchoconstruction

AirwayInflammation

AirwayHyperresponsiveness Airflow

limitation

AsthmaSymptoms

GeneticPredisposition

Environmentalexposures

Asthma:Inflammatory disease

Anti inflammatory treatment

Monitoring of inflammation

Asthma:Inflammatory disease

Obstructive disease

Anti inflammatory treatment

Monitoring of inflammation

bronchodilators

Monitoringlung function

Asthma

Asthma treatment is based on:

Symptoms,Pulmonary function

Assessment of Inflammationin Asthma

Asthma

The problem with symptoms is:• Weak correlation with airway

inflammation• Poor perception• Symptoms in children

underestimatedContinuing inflammation leads to:

Permanent airway changes,

Airway remodeling

Assessing AirwayInflammation

Mostly difficult-to-perform tests inchildhood asthma.

• Mucosal biopsy, • BAL, • Measurement of inflammatory

mediators in; induced sputum, exhaled breath, urine and serum

Assessment of AirwayInflammation

Invasive methods: • Mucosal biopsy• BAL • Difficult toperform widely

Mucosal Biopsy

• Gold standard• Invasive• Unable todistinguish differentwheezingphenotypes

Bronchoalveolar Lavage

• Alternative to biopsy• Cell distribution, eosinophils, ECP, Leukotriene B4, E4, PGE2, IL 8,tryptase• Able to distinguish children with atopic

asthma and viral wheezing• Overlap

BAL ECP and IL 8

Kim Clin Exp Allergy 2005;35:591-7

n=16 n=18 n=143.3 yrs 1.3 yrs 3.7 yrsrec wheezeß2 agonist responseatopic

Induced SputumEosinophil, LXA4, elastaseAdvantages; • Easy to monitor,• Measurement of cells and soluble

mediators, • Correlation with inflammation,• Easy to perform

Induced Sputum

Disadvantages: • Unable to get sample, • Standardisation problems

• Can be an appropriate method formonitoring airway remodeling

Induced SputumEosinophil counts can be used in:• Diagnosis of asthma and monitoring

the treatment.• Patients having eosinophilia in induced

sputum give better response to ICS treatment and eosinophil ratesdecrease after treatment.

• The presence of eosinophilia in inducedsputum indicates an increase in ICS dosage or LTRA supplementation.

1

10

100

1000

10000

Eosi

noph

ils (X

103 /g

)

p<0.05

p<0.001

p<0.01

Controlgroup

Intermittentasthma

Mild to moderateasthma

Severeasthma

p<0.001

Sputum eosinophil counts in asthma

Louis R et al Am J Respir Crit Care Med 2000

Gibson, P G et al. Thorax 2003

Sputum eosinophils (%) and clinical asthmapattern

*p<0.05 v persistent

n=143

Eos <3% Eos >3%

Number 9 14 Age 53 45 Male 5 11 Atopy 2 8 Current smoker 3 1 Δ FEV1 (ml) 100 [-193, 394] 142 [-5, 289] Δ Symptom VAS (mm) -0.7 [15.4, -16.8] -24.4 [-12.5, -36.3]Δ PEF amplitude % mean -3.2 [4.3, -10.7] -7.0 [-2.5, -11.6] Δ PC20 (doubling doses) 0 [-1.2, 1.2] 2.1 [1.3, 3.0] Decrease sputum eos (fold) 1.6 [0.98, 2.7] 7.1 [3.7, 13.5]

Pavord et al. Lancet 1999;353:2213-4

Sputum eosinophilia and the response to budesonide

Sputum eosinophils 2 and 4 wk after treatment

Beclomethasone1.0mg/d Salmeterol

Bacci et al. ERJ 2002

Sputum eosinophils during stepwise steroid reduction

V 1 V 2 V 3 V 4 V 1 V 2 V 3 V 4

0

10

20

30

**

**

*

*

*

exacerbationduring ICSreduction

% e

osin

ophi

lsstableduring ICSreduction

Zacharasiewicz et al. Am J Respir Crit Care Med 2005

.

free

elas

tase

(µg/

ml)

0

10

20

30

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60

control asthma CB

0

10

20

30

40

50

60

tota

lelast

ase(µ

g/ml)

control asthma CB

Elastase in sputumVignola et al,Am JRespir CritCare Med 1998

** **** **

Induced sputum

Inflammationabsent

No symptoms: Consider: decrease ICS

Plus symptoms: Consider: LABPlus symptoms +no variable airway obstruction: Decrease ICS??

Present

Eosinophilic: Consider: increase ICS, LTRA

Neutrophilic: Consider:other treatments:Macrolides, theophyllineDecrease ICS??

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12

Severeexacerbations

Time (months)

BTSmanagement

Sputummanagement

Asthma management based on normalisation of sputum eosinophils

Green RH et al. Lancet 2002

Exhaled Nitric Oxide (ENO) Measurement

Exhaled Nitric Oxide(ENO) Measurement

• Can also be used in monitoringthe patient,

• Patients having exacerbationshave high ENO levels.

Kharitonov A et al Am J Respir Crit Care Med 1996

Raised exhaled NO in asthma

Exhaled NOKharitonov et al, Lancet 1994

800

700

600

500

400

300

200

100

0

Control AsthmaticsSubjects without with ICS

Peak

eNO

(ppb

)

Non-invasive measurements eNO

Avital Pediatr Pulmonol 2001;32:308-132-7 yrs 3-7 yrs 2-7yrs 4-6yrs

Diagnostic value of FeNO

• healthy (n = 34) • asthma (n = 28) • FeNO fall with

increasing flow rate

• FeNO was higherin asthma(p < 0.001)

At each rateboth collection techniques

Deykin A et al. Am J Respir Crit Care Med 2002

Exhaled Nitric Oxide(ENO)

Baraldi et al. J Pediatr 1997.

Exhaled nitric oxide• FENO correlates with eosinophilic airway

inflammation

0,0001

0,001

0,01

0,1

1

1 10 100 1000

Exhaled NO

MB

P de

nsity

epi

thel

ium r=0.40

p=0.022

Van den Toorn et al. AJRCCM 2001

0 Asthma

• remission

Exhaled Nitric Oxide(ENO) Measurement

Advantages: • Non-invasive• Correlation witheosinophilicinflammation,• standardised

Exhaled Nitric Oxide(ENO) Measurement

• Can be performed by 4 years old. Limitations:–Corticosteroids sensitive; time

scale of change?–Costs, expensive equipments–Role to assess remodelling?

But devices are getting cheaperand simple.

Titrating steroids on FENO

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0 100 250 500 750 10000

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0 100 250 500 750 1000

FENO group GINA group% patients

Fluticasone µg/day Fluticasone µg/day

Median: 100µg/day

Mean: 370µg/day

Median: 750µg/day

Mean: 641µg/day

% patients

p = 0.008 for between group comparisons

Smith et al. NEJM 2005; 352: 2163-73.

Monitoring Exhaled NOSmith et al N Engl J Med 2005

Monitoring Exhaled NOSmith et al N Engl J Med 2005

V 1 V 2 V 3 V 4 V 1 V 2 V 3 V 4

0

50

100

150

200

250 exacerbationduring ICSreduction

stableduring ICSreduction

**

***

***

eNO

(ppb

)

**

FeNO during stepwise ICS reduction in exacerbated and stable children

Zacharasiewicz et al. Am J Respir Crit Care Med 2005

Exhaled Nitric Oxide• Titrating ICS on FENO and symptoms

results in:1. Less bronchial hyperresponsiveness 2. With the same dose of ICS3. More inflammation in symptom

group?• ENO high plus symptoms; increase

ICS. • ENO low plus symptoms differential

diagnosis?

mea

n PD

20 m

etha

chol

ine

(ug)

2000

1000900800700600

500

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300

200

100

Visit

6543210

ICS

dose

(mic

rogr

ams)

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GROUP

2,00

1,00

Titrating Steroids on Exhaled Nitric Oxide in Asthmatic Children: a Randomized Controlled Trial.Pijnenburg et al. AJRCCM, 2005.

85 atopic asthmatic children. ICS dose in FENOgroup: increase if >30ppb; no change if <30ppb and symptoms still present; decrease if <30ppb and reduced symptoms.

A a a a

FENO

FENO

Symptoms

Symptoms

Changes in ICS dose (micrograms) Changes in PD20 methacholine

P = 0.04 P = NS

FeNOlow

No symptoms: Consider: decrease ICS

+ Symptoms: Consider + LABPlus Symptoms+ no variable obstruction:Consider alternative diagnosis:Postviral BHR, VCD, CF,PCD,Gastroesophageal reflux etcConsider reducing treatment ?

high

+Symptoms: Consider: high allergen load

non complianceinhalation technique

Consider: increase ICS

No symptoms:Consider: No change?

Inflammatory Markers in Serum

Oldest methodsSerum eosinophil count, ECP, Total ve Specific IgE levels

Inflammatory Markers in Serum

Serum eosinofil count:• Weakly correlated with the eosinophil

count in biopsy• Not specific for asthmaECP levels:• Correlation with biopsy is NOT clear• Sensitivity is more than blood

eosinophil count but less thaneosinophils in sputum

Serum markers

Reichenbach et al Ann Allergy Asthma Immunol 2002:89:498-502

Inflammatory Markers in Urine

Eosinophil peroxidase (EPX):Less invasive than serum ECP, Alternativeİdrarda LTE4: Requires experienceNot specific for asthmaMore studies are required to confirmthe correlation of urine measurementswith inflammation

Exhaled BreathCondensate

• CO andhydrocarbons in exhaled breathcan also be measured.

Exhaled Breath Condensate• Collection of exhaled air by

condensation • Patient breathes into condenser for

10 min condensed water, volatile compounds and particles present in the airway lining fluid )

• Not standardised

Exhaled Breath Condensate8-isoprostane, H2O2, leukotrienes (LTC4,

LTB4), airway pH etc.Correlation with eosinophils and

symptoms is highly variableEarly to recommend in daily practice

Because of these limitations, newstrategies for monitoring airwayinflammation are under investigation

Monitoring AirwayInflammation

Ideal “Inflammometry”:• Cheap• Easy to maintain and calibrate• Completely non-invasive• Easy to use, no co-operation needed• Direct measurement of all relevant

aspects of inflammation• Rapid availability of answers• Evidence of beneficial clinical

outcomes

Comparison of methods

Time forpatient

Time to result

comfort value

Induced Sputum

30 min ~2 h +? +/ -

+ + +

+ +

good

FeNO 5 min instant good

Exhaled Breath Condensate

10 min ~ 3h orinstant

?

Why Measure Inflammation?

• Mechanisms of DiseaseOverlap between groups unimportantCross-sectional studies informative

• Delineate Asthma PhenotypesOverlap importantMay need longitudinal and cross-sectional work

• Monitor Asthma Control and TherapyLongitudinal data essentialClear differentiation between groupsClinically relevant outcomes

Future vision of asthma management

• NO levels• Symptoms• Treatment Days

NO Asthma worsenedTreatment adjusted

Stable

Home

Stored (asthma/treatment history)

Eosinophilicinflammation interpretation

unlikely

might be

very likely

Further investigations: PCD, CF

Steroid naive: unlikely to respond to ICS, consider alternative diagnosis

Steroid treated: taper ICS; if symptomatic: consider alternative diagnosis

Symptomatic: consider other treatments (LABA, LTRA), consider infection

Asymptomatic: baseline?

Steroid naive: response to steroids likely

Steroid treated: consider compliance, inhalation technique, allergen exposure, steroid dose, loss of control, resistance

FENO (ppb)

5

25

35

Exhaled NO • Probably the best of the

available methods• Where to use ?: • After remission• Titrating ICS dosage• Predicting the response to ICS• Choosing the type of additional

treatment

Exhaled NO Where to use ?:• Predicting exacerbations• Monitoring adherence• Asthma screening• Diagnosis