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Practical Immunology and Serology Lab.7 Hawler Medical University College of Health Sciences Clinical Biochemistry Dept. Ass. Lec. Amer Ali Khaleel (M.Sc. Medical Immunology) Helicobacter pylori

Helicobacter pylori 

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Page 1: Helicobacter pylori 

Practical Immunologyand Serology

Lab.7

Hawler Medical UniversityCollege of Health SciencesClinical Biochemistry Dept.Ass. Lec. Amer Ali Khaleel

(M.Sc. Medical Immunology)

Helicobacter pylori

Page 2: Helicobacter pylori 

Introduction:

• Helicobacter pylori is major human pathogen associated with gastric antral epithelium in patients with active chronic gastritis.

• H. pylori is the bacterium (germ) responsible for causing most stomach and duodenal ulcers and many cases of stomach inflammation (chronic gastritis) & cancer.

• H. pylori testing is used to diagnose an infection due to the bacteria and to evaluate the effectiveness of treatment.

• The organism is present in 95% to 98% of patients with duodenal ulcers and 60% to 90% of patients with gastric ulcers.

Page 3: Helicobacter pylori 

•Transmissible• Oral-oral and oral-fecal

• Infects the human stomach.

•Produces inflammatory response.

•This brings up the point of the importance of “hand washing”.

H. pylori Infection transmission:

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Symptoms of H. pylori infection:

• Abdominal pain with burning or gnawing sensation.

• Pain is often made worse with empty stomach; night time pain is

common.

• Poor appetite.

• Weight loss.

• Heart burn.

• Indigestion (dyspepsia)

• Belching.

• Nausea.

• Vomiting.

• Blood in stool.

Page 5: Helicobacter pylori 

Whole Blood

Serum

Plasma

Stool

Breath Test

Biopsy.

Specimens:

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Time Consuming

MethodsNo.

Serology level

10-15 minH. pylori Antibody Test Cassettes or Strips by Immunochromatography assay1

10-15 minH. pylori Antigen Stool (fecal) Strips test by chromatographic Immunoassay2

10-15 minH. pylori Urea Breath Test (UBT)3

2 hoursELISA (IgG/ IgM/ IgA)4

45 minutes –2 hours

ECL (IgG/ IgM)5

Molecular level

7-10 daysPCR (Polymerase Chain Reaction)6

Laboratory Diagnosis of Helicobacter pylori :

Page 7: Helicobacter pylori 

• Widely available.

• Positive result may reflect previous (old) rather than current (recent)

infection not recommended for confirming eradication.

• Blood tests are used to measure antibodies to H. pylori.

• Test not recommended for routine diagnosis or for evaluation of

treatment effectiveness.

• Blood tests for H. pylori cannot tell if you have a current infection or

how long you have had it, This is because the test can be positive for

years even if the infection is cured.

1-H. pylori antibody test cassette or strips by ICA.

Page 8: Helicobacter pylori 

1-H. pylori antibody test cassette or strips by ICA.

• Detects antibodies to the bacteria and will not distinguish previous

infection from a current one.

• If test is negative, then it is unlikely that a person has H. pylori

infection.

• If ordered and positive, results should be confirmed using stool antigen

or breath test.

• As a result, blood tests cannot be used to see if the infection has been

cured after treatment.

Page 9: Helicobacter pylori 

2- H. pylori antigen stool (fecal) stripes test ICA

• Detects directly the presence of H. pylori antigen in a stool sample.

• A stool test can detect traces of H. pylori in the feces.

• This test can be used to diagnose the infection and confirm that it has

been cured after treatment.

•Useful before and after treatment.

•Process of stool collection may be distasteful to patient.

•False positive result possible with recent use of antibiotics or bismuth

preparation.

•The test is for qualitative detection of H. pylori antigen in stool sample

and dose not indicate the quantity of the antigens.

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• H. pylori Ag Rapid test kit result window has 2 pre-coated lines, "T"

(H. pylori Ag Test Line) and "C" (Control Line).

• Both the Test Line and the Control Line in result window are not visible

before applying any samples.

• The Control Line is used for procedural control and should always

appear if the test procedure is performed correctly.

• H. pylori Ag Rapid test kit can identify Helicobacter pylori antigen in

human fecal specimen with a high degree of sensitivity and specificity.

Principle:

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Procedure of the Test (Refer to figure):

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The results are to be interpret as follows:

• One green line = negative (control test)

• One green line AND one red line = positive

• No line = invalid*

* The absence of the control line, which is the upper green

line, makes the result invalid. In this case, the sample must be

retest.

Interpreting the results:

Page 13: Helicobacter pylori 

3- H. pylori breath Test (Carbon Isotope-urea Breath Test, or UBT).

•A person drinks a liquid containing a low level of radioactive material that is harmless or a nonradioactive material.

• If H. pylori is present in the person's gastrointestinal tract, the material will be broken down into "labeled" carbon dioxide gas that is expelled in the breath.

exalenz.com

Page 14: Helicobacter pylori 

Biopsy:

Biopsy most accurate way to detection of H. pylori infection.

• To remove the tissue sample, you have a procedure called endoscopy.

The procedure is done in the hospital or private sector.

• Usually a biopsy is done if endoscopy is needed for other reasons.

Reasons include diagnosing the ulcer, treating bleeding, or making sure

there is no cancer.

• The test may also be recommended for a condition called dyspepsia.

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Limitation of the test:

•A negative result does not preclude the possibility of

infection with H. pylori. Other clinically available tests are

required if questionable results are obtained.

•As with all diagnostic tests, a definitive clinical diagnosis

should not be based on the results of a single test, but should

only be made by the physician after all clinical and

laboratory findings have been evaluated.

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Patient physician laboratory Detection

Helicobacter pylori

in the specimen (Serum)

Positive

Medication

after one month

Detection

Send the biopsy into Endoscopy +VE Helicobacter pylori

histological laboratory (take Biopsy) in the specimen (Stool)

Eradication therapy

Flow-chart

Confirmation

of cure

Page 17: Helicobacter pylori 

1- Trying to drawing of blood sample from your colleagues.

2- Preparation of serum.

3- Do H. pylori for your colleagues.

4- Report the result and interpretation.

Practical Part

Safety Guidelines1-You must wear a lab coat (and do it up) in all Immunology labs.

2-At the end of the lab. clean your lab bench and equipment.

Page 18: Helicobacter pylori 

Any Questions