Product Manual

•
The performance characteristics of this test with specimens from pediatric patients
have not been established.
• A positive result only means the presence of antibodies to H. pylori and does not
i
ndicate any disease status of the patient. A positive test result does not allow one to
distinguish between active infection and colonization by H. pylori.
• A negative result suggests that antibodies to H. pylori are not present, or are present at
a level below the detection limit. If the test result is negative and infection of H. pylori is
s
uspected, additional testing such as culture and histological analysis is recommended.
EXPECTED RESULTS
•
H. pylori is detectable in nearly 100% of adult patients with duodenal ulcer and about
80% of patients with gastric ulcer.
13,17
OSOM H. pylori demonstrated positive results for
94% of patients with a symptom of ulcer and positive results on 80% of gastritis patients.
•
The prevalence of H. pylori antibody increases with age, and is detectable in 5% of
children, about 33% in blood donors, and approaches 50% at age 60 in the normal
population of industrialized nations.
16,18
More than 25% of these infected patients are
asymptomatic. Other factors such as socioeconomic status, ethnic group, different
p
opulations, geographical location and the type of clinical symptoms associated with
the infection also contribute to the observed variations in prevalence.
•
Asymptomatic and untreated patients continue to test IgG seropositive as long as the
H. pylori organisms are present, even after histological resolution
16
. Hence, positive
results are simply consistent with the diagnosis of H. pylori-associated gastritis or
duodenal ulcer; whereas, negative results are strong evidence against these diagnoses.
PERFORMANCE CHARACTERISTICS
Clinical specimens were collected from 207 symptomatic and asymptomatic individuals
who presented for endoscopic examination. The age range was 19-83 years with a
mean age of 52 years. The performance characteristics of OSOM H. pylori were evaluated
by comparison to biopsy/histology, agglutination test and ELISA for detection of
anti-H. pylori antibody. The results are summarized in tables below.
Table 1. OSOM H. pylori Test Result versus Biopsy/Histology
Table 2. OSOM H. pylori Test Result versus Agglutination Test
Table 3. OSOM H. pylori Test Result versus ELISA
Biology/
Histology
+-Total
+ 71 14 85
-3115 118
Total 74 129 203
OSOM
®
H. pylori Test
Agglutination
Test
+-Total
+ 80 8 88
-6113 119
Total 86 121 207
OSOM
®
H. pylori Test
ELISA
+-Total
+ 78 10 88
-6113 119
Total 84 123 207
OSOM
®
H. pylori Test
When biopsy/histology was used as a
reference, the OSOM H. pylori Test
demonstrated 95.9% sensitivity, 89.1%
specificity and 91.6% agreement. Four
tests were excluded in the calculation
due to indeterminate results.
When the agglutination test was used
as a reference, the OSOM H. pylori Test
demonstrated 93.2% agreement.
When ELISA was used as a reference,
the OSOM H. pylori Test demonstrated
92.3% agreement.