Label-free detection of pepsinogen 1 and 2 by polyethylene coating Lamb microfluidic device.

Early screening of gastric cancer is a critical importance for the improvement of patients' survival rate. Here, a polyethylene coating Lamb (PE-Lamb) microfluidic device with immune layer for gastric cancer label-free detection was constructed. Two serum pepsinogen 1 (PG1) and pepsinogen 2 (PG2) biomarkers were applied to screen and predict the appearance of gastric cancer. Compared with enzyme-linked immunosorbent assay (ELISA), this method achieved a higher sensitivity and less time (40 min vs 120 min). The limit of detections (LOD) were reached 60 pg/mL for PG1 and 30 pg/mL for PG2, which have two orders of magnitude lower than traditional ELISA. The linearity coefficient indexes (R2) for PG1 and PG2 were 0.992 and 0.953 respectively, which is similar to that of ELISA. In addition, PG1 and PG2 mixed antigens sample with human serum was detected by PE-Lamb approach, and the frequency response showed high reproducibility and specificity. The results indicate that PE-lamb diagnostic technique is a novel and promising method for high-throughput screening and early diagnosis of gastric cancer.

Influence of laboratory-related and endoscopy-related factors on the assessment of serum pepsinogens and gastrin-17.

BACKGROUND AND AIM: Serum pepsinogen I (PGI) and pepsinogen II (PGII) are noninvasive parameters in the detection of atrophic gastritis. The diagnostic add-on value of serum gastrin-17 (G-17) remains uncertain. The aim of this study was to assess the stability of these serum parameters over time and to evaluate the influence of clinical factors, such as upper gastrointestinal (GI) endoscopy and bowel cleansing, on serum PGI, PGII, and G-17 assessment. PATIENTS AND METHODS: A prospective study was carried out in healthy individuals and patients. For the stability analyses, the plasma and serum samples from 23 individuals were processed at different time points with and without the addition of a stabilizer. Ten patients were included to evaluate the influence of upper GI endoscopy and 18 patients to evaluate the effect of bowel cleansing before colonoscopy. RESULTS: PGI, PGII, and G-17 levels were not statistically different in the serum and plasma. PGI and PGII serum levels were stable over time. G-17 is associated with time-dependent degradation (P=0.0001). The addition of the G-17 stabilizer showed no improvement in stability. Upper GI endoscopy and bowel preparation before colonoscopy were associated with minimal variations in PGI and PGII, whereas G-17 showed patient-specific alterations. CONCLUSION: PGI and PGII serum levels are stable over time. However, G-17 stability is strongly dependent on the time of processing and storage; therefore, samples for G-17 analysis need to be processed no later than 6 h after blood collection. Upper GI endoscopy and colonoscopy preparation lead to minimal nonsignificant changes in basal PGI, PGII, and G-17 levels.

The serum pepsinogen levels for risk assessment of gastric neoplasms: New proposal from a case-control study in Korea.

To decrease the gastric cancer related mortality rate, endoscopic screening is widely performed in Korea. However, a precise method for identifying those at a high risk of gastric neoplasms has not been established. This study aims to evaluate serum pepsinogen (PG) levels for risk assessment of gastric neoplasms. Between August 2014 and March 2016, a total of 398 subjects, including 87 with gastric neoplasms, were enrolled in this study. On the basis of the serum PG I/II ratio, the enrolled subjects were classified into 4 groups: group A, PG I/II ratio >4; group B, >3 and ≤4; group C, >2 and ≤3; group D, ≤2. Compared with group A, a stepwise increase in the risk of gastric neoplasm was observed from group B [odds ratio (OR) = 9.9, 95% confidence interval (95% CI) = 4.0-24.4] to group C (OR = 20.9, 95% CI = 8.7-50.5) to group D (OR = 37.3, 95% CI = 14.3-97.4). The optimal cutoff value of the serum PG I/II ratio for predicting gastric neoplasms was 4.5, with a sensitivity of 97.7% and a specificity of 57.6%. A decrease in the serum PG I/II ratio was strongly associated with an increased risk of gastric neoplasms. The serum PG I/II ratio can be used to identify those at a high risk of gastric neoplasms in Korean population.

A Serological Biopsy Using Five Stomach-Specific Circulating Biomarkers for Gastric Cancer Risk Assessment: A Multi-Phase Study.

OBJECTIVES: We aimed to assess a serological biopsy using five stomach-specific circulating biomarkers-pepsinogen I (PGI), PGII, PGI/II ratio, anti-Helicobacter pylori (H. pylori) antibody, and gastrin-17 (G-17)-for identifying high-risk individuals and predicting risk of developing gastric cancer (GC). METHODS: Among 12,112 participants with prospective follow-up from an ongoing population-based screening program using both serology and gastroscopy in China, we conducted a multi-phase study involving a cross-sectional analysis, a follow-up analysis, and an integrative risk prediction modeling analysis. RESULTS: In the cross-sectional analysis, the five biomarkers (especially PGII, the PGI/II ratio, and H. pylori sero-positivity) were associated with the presence of precancerous gastric lesions or GC at enrollment. In the follow-up analysis, low PGI levels and PGI/II ratios were associated with higher risk of developing GC, and both low (<0.5 pmol/l) and high (>4.7 pmol/l) G-17 levels were associated with higher risk of developing GC, suggesting a J-shaped association. In the risk prediction modeling analysis, the five biomarkers combined yielded a C statistic of 0.803 (95% confidence interval (CI)=0.789-0.816) and improved prediction beyond traditional risk factors (C statistic from 0.580 to 0.811, P<0.001) for identifying precancerous lesions at enrollment, and higher serological biopsy scores based on the five biomarkers at enrollment were associated with higher risk of developing GC during follow-up (P for trend <0.001). CONCLUSIONS: A serological biopsy composed of the five stomach-specific circulating biomarkers could be used to identify high-risk individuals for further diagnostic gastroscopy, and to stratify individuals' risk of developing GC and thus to guide targeted screening and precision prevention.

Gastric plasma biomarkers and Operative Link for Gastritis Assessment gastritis stage.

INTRODUCTION: The Operative Link for Gastritis Assessment (OLGA) staging system has been proposed as a histopathological reporting system of gastric atrophy. Noninvasive methods for indirect evaluation of gastric mucosal atrophy by biomarkers are also being introduced. OBJECTIVES: To analyze gastric mucosal atrophy by biomarkers, pepsinogen I (PgI), pepsinogen II (PgII), PgI/PgII ratio, fasting gastrin-17 (G-17), stimulated gastrin-17 (sG-17), in relation to OLGA gastritis stage. PATIENTS AND METHODS: Gastric biopsies were taken from 269 prospective patients referred for upper endoscopy because of dyspeptic problems and evaluated by two expert pathologists (D.J. and P.S.). Atrophy was assessed according to the OLGA staging system. Pg I, PgII, Pg I/II, G-17, sG-17 were determined in a plasma sample. RESULTS: The mean levels of PgI and PgI/PgII decreased significantly from 90.8 µg/l and 7.6 in stage 0 gastritis to 64.3 µg/l and 4.3 in high-stage gastritis. The mean values of G-17 and sG-17 were significantly higher among patients with stage II gastritis compared with stage 0 and high-stage gastritis.The proportion of patients with normal mucosa and nonatrophic gastritis according to biomarkers decreased from 78% in stage 0 to 22% in high-stage (III-IV) gastritis. Among the latter no case with normal mucosa, according to biomarkers, was observed. CONCLUSIONS: A significant inverse correlation between the mean levels of PgI, PgI/II ratio and the OLGA stage was observed. Percentage of dyspeptic patients with normal mucosa, by blood biomarkers, decreased with increasing OLGA gastritis stages. OLGA staging system provides a good frame for scientific analysis of gastric mucosal atrophy.

Serological assessment of gastric intestinal metaplasia and atrophy using pepsinogen-I, pepsinogen-II and gastrin-17 levels in a low incidence area of gastric cancer endemic for H. pylori infection.

BACKGROUND: Intestinal metaplasia (IM), a precursor of gastric cancer (GC), may be amenable to non-invasive assessment. AIMS: We evaluated the diagnostic utility of serum PG-I, PG-II, PG-I/PG-II ratio and gastrin-17 (G-17) to detect IM and atrophy. METHODS: The study was conducted at a tertiary care center located in low-incidence area of GC, endemic for H. pylori. The evaluation was designed as a prospective case-control study. Patients with GC and dyspepsia were evaluated by endoscopy, histology for IM (H&E, PAS and Alcian blue stains) and H. pylori (H&E and Giemsa stains), rapid urease test and IgG antibody (positive results in any two assays). Serum levels of PG-I, PG-II and G-17 were estimated using ELISA. RESULTS: Of the 98 patients with GC and 62 with dyspepsia, 35 (36%) and 9 (14%) had IM, respectively (p = 0.004). Patients with IM (n = 44) had lower PG-UPG-II ratio than those without IM (n = 116; median 4.4, 0.37-23.6 vs. 6.3, 0.19-38.6, respectively; p = 0.005). A cut-off value of PG-I/PG-II ratio of 6.0 had 64% sensitivity and 52% specificity for detecting IM (area under ROC curve 0.64). 26/44 (60%) patients with IM and 52/98 (53%) with GC had PG-I/PG-II ratio < 6. Serum G-17 was comparable among patients with and without IM. CONCLUSIONS: Though the PG-I/PG-II ratio was lower in patients with IM, only 60% had a lower ratio suggesting that this test and G-17 may not be useful to detect IM in low-incidence areas of GC, endemic for H. pylori infection.

Anti-parietal cell antibody and serum pepsinogen assessment in screening for gastric carcinoma.

BACKGROUND: Anti-parietal cell antibody is found in patients with Helicobacter pylori-positive gastritis and is related to atrophic gastritis and gastric carcinoma. AIM: To identify the characteristics of patients at high-risk for gastric carcinoma in terms of anti-parietal cell antibody and serum pepsinogen. PATIENTS AND METHODS: Subjects were 92 H. pylori-positive patients (54 men, 38 women; mean age, 57.9 years; range, 15-88 years). The serum concentrations of pepsinogen I and II were determined by radioimmunoassay, and the presence of anti-parietal cell antibody was assessed by enzyme-linked immunosorbent assay. Degrees of inflammation and atrophy in the corpus of the stomach were evaluated histologically. RESULTS: Patients were classified into four groups according to anti-parietal cell antibody status and pepsinogen I/II ratio. Anti-parietal cell antibody-negative/pepsinogen I/II-low patients had the highest risk for gastric carcinoma (prevalence of gastric carcinoma: 7/13=53.8%, odds ratio=7.6, 95% confidence interval, 1.2-48.0). Anti-parietal cell antibody titre was high when inflammation in the corpus was severe (p=0.06) and significantly low when atrophy in the corpus was severe (p=0.01). CONCLUSION: Our results showed that patients with a negative anti-parietal cell antibody titre and low pepsinogen I/II ratio are at high-risk for gastric carcinoma.