title: Case report: anti-Coa in a Co-(a+)-typed patient with chronic renal insufficiency.
abstract: The recently identified molecular structure of the Colton blood group system is characterized by an amino acid substitution at position 45 (Colton a: alanine, Colton b: valine) of the archetypical water channel protein Aquaporin-1 (AQP1), which regulates water homeostasis in the erythrocyte membrane and in the proximal tubule of the nephron. We identified a patient with the unique constellation of an antibody with the specificity anti-Coa and the Co (a+) phenotype. The serological antigen typing was confirmed by molecular typing with PCR-RFLP. The antibody has to be interpreted as an antibody against a partial Colton a antigen or as an autoantibody despite a negative direct antiglobulin test (DAT). The patient is suffering from chronic renal insufficiency of unknown origin, rising speculation about a pathophysiological relationship between the serological constellation and the clinical disease under the aspect of localization of the Colton antigens on AQP1.
authors.affiliation: Institut für Immunologie, Ruprecht-Karls-Universität Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Leo
authors.forename: J P
authors.initials: JP
authors.lastname: Cartron
authors.forename: M
authors.initials: M
authors.lastname: Strittmatter
authors.forename: G
authors.initials: G
authors.lastname: Rowe
authors.forename: D
authors.initials: D
authors.lastname: Roelcke
mesh_terms: D000328:Adult; D051398:Aquaporin 1; D020346:Aquaporins; D001789:Blood Group Antigens; D001788:Blood Grouping and Crossmatching; D006801:Humans; D007473:Ion Channels / Q000097:blood; D007518:Isoantibodies / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood*; D008297:Male; D010641:Phenotype; D006435:Renal Dialysis
chemical_list: C496020:AQP1 protein, human; D020346:Aquaporins; D001789:Blood Group Antigens; D007473:Ion Channels; D007518:Isoantibodies; D051398:Aquaporin 1