title: Development of a high-specificity sandwich ELISA system for the quantification of human intestinal fatty acid-binding protein (I-FABP) concentrations.
abstract: Intestinal fatty acid-binding protein (I-FABP), a low molecular mass (approximately 15 kDa) cytoplasmic protein, is specifically located in epithelial cells of small bowel mucosal layer. This protein is rapidly released into the circulation after injury and/or destruction of these cells due to poor mesenteric blood flow and necrosis. Therefore, it can be used as a potential diagnostic biomarker for small bowel disease. In the present study, we have succeeded in developing a sandwich enzyme-linked immunosorbent assay (ELISA) system for quantification of human I-FABP. The range of sandwich ELISA system was 0.1-50 ng/mL of I-FABP in serum, and showed excellent quantitative characteristics such as reproducibility, dilution linearity, and recovery. No cross-reactivities were detected with other types of FABPs. As measured with this ELISA system, the serum I-FABP concentration was 1.1 ± 0.9 ng/mL in 61 healthy individuals, indicating that the reference value was below 2.0 ng/mL regardless of gender and age. Furthermore, mild abdominal pain or diarrhea before blood sampling did not affect I-FABP levels. Thus, this ELISA system could be used to accurately quantify human I-FABP concentrations in serum samples. These results suggest that it could be used as a new biomarker for the diagnosis of small bowel disease.
authors.affiliation: DS Pharma Biomedical Co., Ltd., Osaka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Funaoka
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kanda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kajiura
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ohkaru
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujii
mesh_terms: D000328:Adult; D000367:Age Factors; D000906:Antibodies / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D050556:Fatty Acid-Binding Proteins / Q000097:blood* / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors
chemical_list: D000906:Antibodies; D015415:Biomarkers; D050556:Fatty Acid-Binding Proteins