Usefulness of Serum Pepsinogen I as a Biomarker in Early Diagnosis of Aetiology of Dyspepsia.

Background: Dyspepsia, according to Rome III criteria, is defined as pain or discomfort centred in the upper abdomen in addition to symptoms like early satiety, postprandial fullness, bloating and nausea. Pepsinogens which are secreted by chief cells of the stomach play an important role in its physiology. They could determine the functional state of the mucosa in health and in diseased conditions. Serum levels of pepsinogen have aided the diagnosis of gastric pathologies such as atrophic gastritis, peptic ulcer disease and gastric cancer. Pepsinogen assay, being a simple, non-invasive procedure, can aid in determining the aetiology of dyspepsia especially in a resource poor setting.

Objective: This was to evaluate the diagnostic significance of serum pepsinogen I in patients with dyspepsia.

Methods: The study involved 112 adult patients with dyspepsia and an equal number of controls. A questionnaire was used to obtain biodata, clinical features and other relevant information. The patients had abdominal ultrasound scan, urea breath test and upper gastrointestinal endoscopy (UGIE), while the controls had only abdominal ultrasound scan. Sera prepared from 10ml of venous blood from each participant were stored at -20ºC and later analysed for pepsinogen I (PG I).

Results: Females predominated in both groups (F:M = 1.4:1). The mean age of cases was 51±15.9 years and was similar to that of controls 51.4±16.5. The most frequent symptom was epigastric pain in 101 (90.2%) patients. Median pepsinogen I level in patients (28.5ng/ml) was significantly lower than in controls (68.8ng/ml) (p<0.001). The most frequent endoscopic finding was gastritis. Serum PG I level at a cut-off point of 79.5ng/ml had a specificity of 88.8% and sensitivity of 40% in identifying dysplasia.

Conclusion: Serum PG I level was lower in patients with dyspepsia than controls. It showed high specificity in identifying dysplasia and could be a biomarker for early gastric cancer.