Biomaterial Database

Rapid protein A assay for intrinsic factor and its binding antibody. 1988

N A Sourial

Department of Haematology, St Bartholomew's Hospital, London.

A simple and rapid method for the measurement of cobalamin bound intrinsic factor (Cbl-IF) complex and intrinsic factor binding antibody is described. The method is based on the principle of affinity chromatography and adapted to a batch separation technique. A specific ligand staphylococcal protein A was coupled to Sepharose to form a convenient solid phase matrix. The intrinsic factor binding antibody in patients with pernicious anaemia was used to form an immune complex with Cbl-IF. This complex was adsorbed on to staphylococcal protein A. Gastric juice from control subjects and patients with pernicious anaemia was assayed for intrinsic factor activity and the results correlated very closely with two other established methods. Sera from 30 control subjects were assayed for binding intrinsic factor antibody and all were found to be negative; of 15 patients with pernicious anaemia, six were positive. These patients were selected with blocking antibody. The method does not require technologically advanced protein separation techniques and could therefore be applied in any clinical laboratory using radioisotopes. It could also be adapted to assay cobalamin in body fluids or in food.

UI	MeSH Term	Description	Entries
D007437	Intrinsic Factor	A glycoprotein secreted by the cells of the GASTRIC GLANDS that is required for the absorption of VITAMIN B 12 (cyanocobalamin). Deficiency of intrinsic factor leads to VITAMIN B 12 DEFICIENCY and ANEMIA, PERNICIOUS.	Factor, Intrinsic
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D005750	Gastric Juice	The liquid secretion of the stomach mucosa consisting of hydrochloric acid (GASTRIC ACID); PEPSINOGENS; INTRINSIC FACTOR; GASTRIN; MUCUS; and the bicarbonate ion (BICARBONATES). (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p651)	Gastric Juices,Juice, Gastric,Juices, Gastric
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000752	Anemia, Pernicious	A megaloblastic anemia occurring in children but more commonly in later life, characterized by histamine-fast achlorhydria, in which the laboratory and clinical manifestations are based on malabsorption of vitamin B 12 due to a failure of the gastric mucosa to secrete adequate and potent intrinsic factor. (Dorland, 27th ed)	Addison's Anemia,Anemia, Addison's,Pernicious Anemia,Addison Anemia,Addisons Anemia,Anemia, Addison,Anemia, Addisons
D000906	Antibodies	Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D013205	Staphylococcal Protein A	A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.	Protein A,Protein A, Staphylococcal
D014805	Vitamin B 12	A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.	Cobalamin,Cyanocobalamin,Cobalamins,Eritron,Vitamin B12,B 12, Vitamin,B12, Vitamin