Pytest

Name: Pytest

Before Using Pytest

In deciding to use a diagnostic test, any risks of the test must be weighed against the good it will do. This is a decision you and your doctor will make. Also, other things may affect test results. For this test, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

The amount of radiation in this agent is very low and considered safe for children. However, be sure you have discussed with your doctor the benefit versus the risk of exposing your child to radiation.

Pregnancy

	Pregnancy Category	Explanation
All Trimesters	C	Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Description

PYtest1 (14C-Urea Breath Test) is a qualitative and non-invasive method for the diagnosis of Helicobacter pylori (H.pylori). To detect H.pylori,14C-urea supplied in a capsule is swallowed by the patient. If gastric urease from H.pylori is present, Urea is split to form CO2 and NH3. Ten minutes after the patient ingests the capsule, a breath sample is collected into a balloon. The breath sample is later transferred to collection fluid to trap the labeled CO2. The liquid sample is then analyzed in a liquid scintillation counter.

The PYtest1 Kit (14C-Urea Breath Test) is designed for use with the PYtest1 capsule, a gelatin capsule for oral administration containing 1 µCi of 14C labeled urea. The urea is adsorbed on sugar spheres and colored yellow with fluorescein.

1 Registered Trademark or Trademark of Kimberly-Clark Worldwide, Inc.

Data on 14C-urea

Structural Formula (14C-urea): NH2 14CONH2

Radiation emission: beta-emission, 49 keVmean, 156 keVmax, no other emissions

External emission: No external radiation hazard. Low-energy beta emissions only. Maximum range of 0.3 mm in water.

Radiological Half-life: 5730 years

Maximum effective dose equivalent (EDE) : 0.3 mrem/µCi

Clinical Studies

Two studies were performed. In both studies, patients with gastrointestinal symptoms underwent the breath test and an endoscopy. During the endoscopy, biopsy samples were taken from the antral gastric mucosa for histological analysis (2 samples, Giemsa stain) and rapid urease test (1 sample, CLOtest1). Breath samples were mailed to the TRI-MED lab where they were read in a liquid scintillation counter.

Results were reported as disintegrations per minute (DPM). Analysis for accuracy used the ten minute breath sample. A breath sample DPM <50 was defined as a negative result. DPM ≥200 was defined as a positive result. DPM in the range of 50 -199 was classified as indeterminate.

STUDY 1

Of 186 patients who had histopathology and CLOtest1 (80 men, 106 women), 53 were infected with H.pylori as determined by agreement between histology and CLOtest1. The study results are summarized below:

Table 1: Study #1 (n=186, Indeterminate results included)

Histology and CLOtest1
	H.pylori	Positive	Negative	Total
Notes: PYtest1 at 10 min. was compared to the gold standard of biopsy results in which histology and CLOtest1 concurred. Patients who did not have both biopsy tests performed, or in whom the tests differed, were excluded from analysis. There was no statistical difference in test accuracy based on gender of patient.
ppv = positive predictive value (true positive divided by total PYtest1 positive)
npv = negative predictive value (true negative divided by total PYtest1 negative)
PYtest1	Positive	51	8	59	ppv. 86%
(DPM	Indeterminate	1	8	9
10m.)	Negative	1	117	118	npv. 99%
	Total	53	133	186
		sensitivity 96%	specificity 88%

STUDY 2

Breath tests were performed on 436 outpatients attending gastroenterology practices at sites in the United States. Seventy-six patients (40 men, 36 women) who had histology and CLOtest1 were evaluated. The results are summarized below:

Table 2: Study #2 (n=76, Indeterminate results included)

Histology and CLOtest1
	H.pylori	Positive	Negative	Total
Notes: PYtest1 at 10 min. was compared to the gold standard of biopsy results in which histology and CLOtest concurred. Patients who did not have both biopsy tests performed, or in whom the tests differed, were excluded from analysis. There was no statistical difference in test accuracy based on gender of patient.
ppv = positive predictive value (true positive divided by total PYtest1 positive)
npv = negative predictive value (true negative divided by total PYtest1 negative)
PYtest1	Positive	22	0	22	ppv. 100%
(DPM	Indeterminate	4	2	6
10m.)	Negative	1	47	48	npv. 98%
	Total	27	49	76
		sensitivity 82%	specificity 96%

Adverse Reactions

No adverse reactions were reported in clinical trials.