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BREATH TEST
A breath test is a type of test performed on air generated from
the act of exhalation.
BREATH TEST
• Breath tests are among the least invasive methods available for
Clinical diagnosis
Disease state monitoring
Environmental exposure
assessment
BREATH TEST-Breath Components
The bulk matrix of breath is a
mixture of nitrogen,oxygen,
CO2, H2O, and inert gases
VOCs
VOCs
BREATH TEST-COMPONENTSVO
Cs Endogenous
Exogenous
Common VOCs
Isoprene
Acetone
Ethane
Methanol
BREATH TEST
Breath tests are among the least invasive methods for
monitoring a person’s disease state or exposure to a drug or an environmental
pollutant.
Interest inbreath analysis for clinical diagnosis has increased inrecent years.
BREATH TESTS-Applications
• Depending on the origin of the substances found in human breath, fall into two main categories:
Diagnosis of diseaseAssessment of exposure
to environmental pollutants
BREATH TEST- Diagnosis of disease
• Ancient Greek physicians already knew that the aroma of human breath could provide clues to diagnosis.
Sweet, fruity odor
Un-controlled diabetes
Musty, fishy reek
Advanced liver
disease
Urine-like smellFailing kidneys
BREATH TEST- Diagnosis of disease
Modern breath analysis started in the 1970s when
researchers,using gas chromatography
(GC), identifiedmore than 200
components in human breath
As a result of extensive studies,
a few breath markers
have been discovered and
successfully used in diagnosisof disease
BREATH TESTS-ApplicationsDisease or application Breath marker
Lipid peroxidation Pentane, ethane
Asthma, COPD, bronchiectasis, ARDS H2O2
Disease or application Breath marker
Asthma NO, CO, H2O2, isoprostanes, nitrite/nitrate
COPD NO, H2O2, eicosanoids
Cystic fibrosis NO, CO, H2O2, isoprostanes,nitrite/nitrate
Pulmonary allograft dysfunction NO
Lung cancer NO
OXIDATIVE STRESS
LUNGDISEASES
BREATH TESTS-ApplicationsDisease or application Breath marker
Diabetes Acetone
Disease or application Breath marker
Disorders of digestion and absorption
H2
Gastritis, duodenal ulcer, gastric ulcer, and gastric cancer
Isotopes of carbon (13C or 14C)
Metabolic disorder
Gastroenteric diseases
BREATH TESTS-Assessment of Exposure to VOCs
• VOCs enter the body mainly through inhalation
Benzene
• Exposure to smoking
Chloroform
• Exposure are chlorinated water
Para-dichlorobenzene
• Moth cakes/room air deodorizers
Substrates of 13C-breath tests for
potential use in
routine clinical
applications and their
diagnostic and metabolic
implications
BREATH TESTS-PROCEDURE
Collect fasting breath sample
BREATH TESTS-PROCEDURE
Give test
meal
BREATH TESTS-PROCEDURE
Collect breath
samples at a
specific interval of
time
FAN nondispersive infrared spectrometric 13C-Breath test analyser
UREA BREATH TESTS
• UBT can be used for the diagnosis of gastroenteric diseases.
Indi
cati
on H. Pylori infection
Lactose and fructose intolerance
Bacterial Overgrowth
Bile salt wastage
Pancreatic insufficiency
Liver dysfunction
Abnormal small-bowel transit
UREA BREATH TESTS
H. pylori infection Gastritis
Duodenal ulcers
Gastric ulcers
Gastric cancer.
Almost all of the routine diagnostics and treatments for these diseases have been replaced by studies focusing on the epidemiology, isolation, and eradication of this single
bacterium .
UREA BREATH TESTS
Currently, two breath tests are available to detect H.pylori:
14C UBT (radioactive) 13C UBT (nonradioactive, stable)
Requires gas isotope ratio MS to
analyze
Contraindicated in children and in
pregnant women
UREA BREATH TESTS
Intake of 13C labeled urea together with test meal
30 minutes later
Hp negativeNo enzymatic reaction, little
13CO2 in breath
Hp positiveEnzymatic
reaction, 13CO2 in breath
•Blow up the first breath bag1
•Drink 13C- labeled test liquid •Wait for 30 minutes2•Blow up the second breath bag3•Measurement 4
UREA BREATH TESTS
The concept of 13C breath testing is based on measuring the ratios of
two non-radioactive isotopes of the Carbon atom in the form of CO2:
Carbon 12 (12C) and Carbon 13 (13C).
[13C]LACTOSE BREATH TESTIndication
lactase deficiency in patients with gastrointestinal symptoms and of measuring lactase activity of brush
border
Metabolism of Substrate
Procedure:
50 g load of lactose naturally enriched in 13C
Lactose is metabolized to CO2
LACTOSE BREATH HYDROGEN TEST
•Lactase deficiency•Lactose malabsorptionIndication
Proc
edur
e Overnight fasting
Brush teeth
Measure fasting breath H2
Give lactose solution 50g in 180ml water
Rinse mouth with 20ml water and swallow
Measure breath H2 at15,30,60,90 & 120min
[13C]ACETATE BREATH TEST
IndicationEvaluation of gastric
emptying of liquid meals
In diabetic patients with symptoms of
gastroparesis
Procedure100 mg of sodium acetate[13C] with a 370 kcal semiliquid test
meal
Samples are taken at10 minute intervals over two hours.
[13C]GLYCINE BREATH TEST
Indication Studying amino acid and protein metabolism
Measuring gastric emptying
Glycine Serine Pyruvate CO2
serine methyl
transferase
serine
dehydrates
Metabolism of Substrate:
•Test meal and 100 mg of [13C]glycine •Sample-every 15 min for 4 hoursProcedure
[13C]CHOLESTERYL OCTANOATE BREATH TEST
•Useful for the diagnosis of pancreatic diseasesIndication
ProcedureAfter a 12 h overnight fast- basal sample
Give 500 mg labeled cholesteryl octanoate[13C]
Sample-every 15 minutes thereafter for six hours
Measure 13CO2 recovery
[13C]AMINOPYRINE BREATH TEST
Indication•Studying hepatic microsomal biotransformation•Diagnosing and assessing therapy of liver diseases
Pro
ced
ure
After an overnight fast-fasting breath sample
Subjects ingest 2 mg per kg body mass [N,N-dimethyl-13C]–aminopyrine
Breath sample at 30 minute intervals for two to three hours
[13C]GALACTOSE BREATH TEST
•Diagnosis of liver diseases•Particularly for the diagnosis of liver fibrosisIndication
ProcedureOvernight fast-Basal sample
Give aqueous solution of 10 g 13C-galactose per m2 of body area
Sample-at 30 minute intervals over threeto four hours.
ADVANTAGES OF BREATH ANALYSISAd
van
tage
s
Breath testing is noninvasive, easily repeated
Breath samples closely reflect the arterial concentrations
Breath is a much less complicated mixture than serum or urine
Breath analysis provides direct information on respiratory function
Breath analysis can dynamically real-time monitor the decay of volatile toxic substances in the body.
LIMITATIONS OF BREATH ANALYSISLi
mit
ation
s Problem in use of breath tests in clinical practice
High water content of breathsamples,
Instruments for breathanalysis are expensive.
Lack of established links between breath substances and disease
REFERENCES Re
fere
nces
13C–Breath Tests in Medical Research and Clinical Diagnosis By Klaus Wetzel and Heinz Fischer
Breath Analysis: Potential for Clinical Diagnosisand Exposure AssessmentBy Wenqing Cao and Yixiang Duan
TIETZ Fundamental of CLINICAL CHEMISTRY
