Human intestinal alkaline phosphatase-binding IgG in patients with severe bacterial infections

Abstract

SUMMARYPatterns of alkaline phosphalase (AP)-binding proteins were observed in the alkaline pH range of 6-5-9-5 upon isoclcctric focusing and blotling of serum from patients with inflammalory diseases. Afler isolation using affinity chromatography on prolein A or immunoaffinity chromatography on AP coupled to cyanogen bromide (CNBr)-activaled Sepharose. the AP-binding protein was identified as IgG on Western blols and in ELISA using human igG-specilic aniibodies. It was shown thai this IgG binds to AP from both calf (bovine) and human intestine. However, it binds neither lo the human liver-bone-kidncy (LBK) isoform nor to bacterial AP. Moderate reaction was observed with human placental AP. Comparing patients with various diagnoses (H = 284), AP-binding antibodies were mainly found in severe bacterial infections. They were not detected in serum from healthy blood donors (rt = 3()0). The presence of AP-binding IgG was independent of the infeeled organ and the bacterial species causing infection. This antibody may be useful for discriminating bacteria! from viral infection and for indicating severe bacterial inflammation.

An alkaline phosphatase transport mechanism in the pathogenesis of Alzheimer’s disease and neurodegeneration

“…TNAP, located by default at the canalicular hepatocyte membrane, is known to be a ligand for the ASGP-R in the liver [19]. Liver TNAP also has the capacity to serve as an antigen for IgG, which itself binds to the ASGP-R in a carbohydrate-independent manner and is present in high concentrations in bile [20][21][22][23][24].…”