Serum pepsinogen reference intervals in apparently healthy Chinese population with latex enhanced turbidimetric immunoassay.

AIM: Serum pepsinogen (sPG) has been used to help in diagnosing atrophic corpus gastritis and in screening for gastric cancer non-invasively. There are as yet no reports on sPG reference intervals (RIs) with latex enhanced turbidimetric immunoassay (LIA). In this study, we established the RIs for sPG in a healthy Chinese population using LIA. METHODS: Serum PGI and PGII levels in a healthy population (aged 17-80 years) were measured simultaneously using LIA. RIs were determined following Clinical Laboratory and Standards Institute C28-A3 guidelines using a non-parametric method. RESULTS: 95% RIs in men (ng/mL) were: ≤40 years old, 25.53-100.76 for PGI and ≤24.42 for PGII; 41-50 years old, 26.62-124.74 for PGI and ≤26.81 for PGII; and 51-80 years old, 30.40-153.25 for PGI and ≤32.62 for PGII. Corresponding RIs for women (ng/mL) were: ≤40 years old, 21.20-87.44 for PGI and ≤25.53 for PGII; and 41-80 years, 26.40-127.46 for PGI and ≤30.18 for PGII. 95% RI for PGI/PGII in both men and women at any age was ≥2.51. CONCLUSIONS: We established the RIs for sPG using LIA in a healthy Chinese population, which can provide a reference for clinical and laboratory studies.

HPLC-FLD determination of serum aromatic amino acids: application in chronic kidney disease patients.

BACKGROUND: The aromatic amino acids (AAA) are very important amino acids in the body and have been suggested to be involved in many diseases. We describe the development and full validation of a high performance liquid chromatography with fluorescence detection (HPLC-FLD) method for simultaneously quantitative determination of serum AAA. Furthermore, we aimed to explore the clinical significances of AAA for chronic kidney disease (CKD). METHODS: Serum samples were deproteinized by perchloric acid. Separation was carried out on a Megres C18 column (4.6 mm×250 mm i.d., 5 µm). The mobile phase consisted of 10% acetonitrile (v/v) in water and was run at a flow rate of 1.0 ml/min. The eluted AAA was monitored by measuring the fluorescence intensity using the programmed wavelength detection setting. RESULTS: AAA determination in a serum sample was achieved in <10 min. The linear ranges of the method were 0.55-275 µmol/l, 3.05-1220.0 µmol/l and 0.049-49 µmol/l for Tyr, Phe and Trp, respectively. The limit of detection (LOD) was 0.014 µmol/l for Tyr, 0.5 µmol/l for Phe, and 0.0049 µmol/l for Trp. Recovery and reproducibility were satisfactory. Compared with healthy control subjects, the CKD patients showed lower serum levels of AAA. It should probably available to apply for screening and monitoring of CKD. CONCLUSIONS: The method is simple, fast, accurate, and suitable for routine analysis.