Method and kit for detecting Helicobacter pylori

• US 6,171,811 B1
• Filed: 07/20/1999
• Issued: 01/09/2001
• Est. Priority Date: 11/12/1996
• Status: Expired due to Term

• Current Assignee: Isomed SL
• Original Assignee: Isomed SL
• Inventors: Becerro De Bengoa Vallejo, Ana
• Primary Examiner(s): Leary, Louise N.
• Application Number:
  US09/101,992
• Time in Patent Office: 539 Days
• Field of Search: 435/34, 435/29, 435/975, 435/968
• US Class Current: 435/34
• CPC Class Codes: C12Q 1/16 using radioactive material
• CPC Class Codes: C12Q 1/58 involving urea or urease
• CPC Class Codes: G01N 2333/205 from Campylobacter (G)
• CPC Class Codes: G01N 33/0055 Radionuclides
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: Y10S 435/968 High energy substrates, e.g. fluorescent, chemiluminescent, radioactive
• CPC Class Codes: Y10S 435/975 Kit

Abstract

The method is based on the carbon-13 labelled urea breath test, which comprises a) administering to the patient an aqueous solution of citric acid at pH comprised between 2 and 2.5; b) collecting a sample of the patient'"'"'s breath with the object of determining the baseline content of carbon-13; c) administering to the patient a suitable amount of carbon-13 labelled urea; d) collecting a sample of the patient'"'"'s breath with the object of determining the content of carbon-13 after the administration of the labelled urea; and e) analyzing the breath samples collected to determine the carbon-13 content before and after the administration of urea labelled with carbon-13. The kit has a container for the citric acid, another for the carbon-13 labelled urea, exetainers destined to containing the patient'"'"'s breath, and means to blow the breath into the exetainers.

Claims

1. A method for the detection of Helicobacter pylori, based on the carbon-13 labelled urea breath test, which comprises the stages of:

a) administering to the patient an aqueous solution of citric acid which comprises citric acid in an amount sufficient to yield a pH comprised between 2 and 2.5;

b) collecting a sample of the patient'"'"'s breath with the object of determining the baseline content of carbon-13;

c) administering to the patient a suitable amount of carbon-13 labelled urea;

d) collecting a sample of the patient'"'"'s breath with the object of determining the content of carbon-13 after the administration of the carbon-13 labelled urea; and

e) analysing the breath sample collected to determine the carbon-13 content before and after the administration of carbon-13 labelled urea.

2. The method according to claim 1, wherein said aqueous solution of citric acid comprises, additionally, acceptable pharmaceutical or food additives, selected from the group formed by sweeteners, flavors, colorants and preservatives.

3. The method according to claim 1, wherein said aqueous solution of citric acid originates from a fruit juice, optionally acidified with an acceptable pharmaceutical or food acidifier.

4. The method according to claim 1, wherein the collection of the patient'"'"'s breath samples for determining the baseline carbon-13 content is carried out approximately 10 minutes after the administration of the aqueous solution of citric acid.

5. The method according to claim 1, wherein the carbon-13 labelled urea is administered in the form of an aqueous solution.

6. The method according to claim 5, wherein said aqueous solution of carbon-13 labelled urea has a concentration comprised between 1 and 4.5 mg/ml.

7. The method according to claim 1, wherein the carbon-13 labelled urea is administered in the form of a tablet.

8. The method according to claim 7, wherein said tablet contains between 50 and 100 mg of carbon-13 labelled urea.

9. The method according to claim 1, wherein the collection of the patient'"'"'s breath samples for determining the carbon-13 content after the administration of the carbon-13 labelled urea is carried out approximately 30 minutes after the administration of the carbon-13 labelled urea.

10. The method according to claim 1, wherein the patient'"'"'s breath is collected in exetainers.

11. The method according to claim 1, wherein the analysis of the breath and the determination of the carbon-13 content is carried out by gas chromatography and mass spectroscopy.

12. The method according to claim 1, wherein the comparison between the baseline carbon-13 content and the carbon-13 content after administration of carbon-13 labelled urea is indicative of the urease activity existing in the patient.

24. A kit for the detection of Helicobacter pylori, by carrying out a method based on the carbon-13 labelled urea breath test according to claim 1, which comprises a case which contains:

a container containing carbon-13 labelled urea;

at least, two containers destined to containing the breath of the patient, one of which is destined to containing the breath of the patient after the administration of the citric acid but before the administration of the carbon-13 labelled urea, while the other container is destined to containing the breath of the patient after the administration of the carbon-13 labelled urea, being said containers constituted by glass tubes provided with screw-cap stoppers fitted with a septum; and

the means to blow the breath into the aforementioned containers.

25. The kit according to claim 24, which additionally comprises a container which contains citric acid.

26. The kit according to claim 25, wherein the citric acid is in the solid state, in an amount such that after dissolution in a suitable amount of water, it yields a pH comprised between 2 and 2.5.

27. The kit according to claim 26, wherein the container containing the citric acid is a sachet.

28. The kit according to claim 25, wherein the container of the citric acid contains, in addition to the citric acid, other acceptable pharmaceutical or food additives, selected from the group formed by sweeteners, flavours, preservatives and colorants.

29. The kit according to claim 24, wherein the container containing the carbon-13 labelled urea is a flask which contains the suitable amount of carbon-13 labelled urea and the flask is of the appropriate volume to obtain the aqueous solution of carbon-13 labelled urea at the desired concentration.

30. The kit according to claim 24, wherein the container containing the carbon-13 labelled urea is a blister which contains a tablet, optionally dispersible, which contains the appropriate amount of carbon-13 labelled urea.

31. The kit according to claim 24, wherein the containers destined to containing the patient'"'"'s breath are exetainers, which are constituted by a tube (1) made of glass, the stoppers of which (2) are threaded and have a septum (3) in the centre, made of an elastomer suited for pharmaceutical purposes, which permits its penetration by means of a needle which collects the air contained in the exetainer for its subsequent analysis.

32. The kit according to claim 24, wherein said means to blow the breath into the containers are straws.

33. The kit for the detection of H. pylori, suited for carrying out a method based on the carbon-13 labelled urea breath test, according to claim 1, which comprises a case which contains:

a sachet containing citric acid, in the solid state, in a quantity sufficient so that, after dissolution in a suitable amount of water, it yields a pH comprised between 2 and 2.5, together with optionally, some additives, such as sweeteners, flavours, preservatives and colorants;

a flask containing carbon-13 labelled urea selected among;

i) a flask which contains the appropriate amount of carbon-13 labelled urea, said flask containing the necessary volume to dissolve the urea and achieve the desired concentration, or alternatively,

ii) a blister containing a tablet, optionally dispersible, with the suitable amount of carbon-13 labelled urea;

four exetainers destined to contain the breath of the patient, two of which are used to collect the patient'"'"'s breath after the administration of the citric acid but before the administration of the aqueous solution of carbon-13 labelled urea, while the other two will collect the patient'"'"'s breath after the administration of the aqueous solution of carbon-13 labelled urea; and

some straws to blow the breath into the exetainers.

34. The kit according to claim 33, wherein said sachet contains between 2 and 5 g of citric acid, optionally together with other additives, for its dissolution in the suitable amount of water.

35. The kit according to claim 33, wherein the flask which contains the carbon-13 labelled urea is a flask of, at least, 20 to 50 ml, which contains between 50 and 100 mg of carbon-13 labelled urea.

36. The kit according to claim 33, wherein said tablet contains between 50 and 100 mg of carbon-13 labelled urea.

37. The kit according to claim 33, wherein said exetainers are labelled so that it is possible to distinguish easily between the exetainers destined for use in collecting the breath from before the administration the carbon-13 labelled urea from those used to collect the breath from after the administration of the carbon-13 labelled urea.

13. The method for the detection of Helicobacter pylori, based on the carbon-13 labelled urea breath test, which comprises the steps of:

a) collecting a sample of the patient'"'"'s breath with the object of determining the baseline content of carbon-13;

b) simultaneously administering to the patient;

an aqueous solution of citric acid which comprises citric acid in an amount sufficient to yield a pH comprised between 2 and 2.5; and

a suitable amount of carbon-13 labelled urea;

c) collecting a sample of the patient'"'"'s breath with the object of determining the content of carbon-13 after the administration of the solution of citric acid and of carbon-13 labelled urea; and

d) analysing the breath samples collected to determine the carbon-13 content before and after the administration of carbon-13 labelled urea.

14. The method according to claim 13, wherein said aqueous solution of citric acid comprises, additionally, acceptable pharmaceutical or food additives, selected from the group formed by sweeteners, flavours, colorants and preservatives.

15. The method according to claim 13, wherein said aqueous solution of citric acid originates from a fruit juice, optionally acidified with an acceptable pharmaceutical or food acidifier.

16. The method according to claim 13, wherein the carbon-13 labelled urea is administered dissolved in an aqueous solution.

17. The method according to claim 16, wherein said aqueous solution of carbon-13 labelled urea has a concentration comprised between 1 and 4.5 mg/ml.

18. The method according to claim 13, wherein the carbon-13 labelled urea is administered in the form of a tablet.

19. The method according to claim 18, wherein said tablet contains between 50 and 100 mg of carbon-13 labelled urea.

20. The method according to claim 13, wherein the collection of the patient'"'"'s breath samples for determining the carbon-13 content after the administration of the carbon-13 labelled urea is carried out approximately 30 minutes after the administration of the carbon-13 labelled urea.

21. The method according to claim 13, wherein the patient'"'"'s breath is collected in exetainers.

22. The method according to claim 13, wherein the analysis of the breath and the determination of the carbon-13 content is carried out by gas chromatography and mass spectroscopy.

23. The method according to claim 13, wherein the comparison between the baseline carbon-13 content and the carbon-13 content after administration of carbon-13 labelled urea is indicative of the urease activity existing in the patient.