ALLOTYPE IMMUNOGLOBULIN ENHANCES ALKALINE-PHOSPHATASE ACTIVITY - IMPLICATIONS FOR THE INFLAMMATORY RESPONSE

To understand the interactions among components of the immune/inflamma tion response, we studied the effects of immunoglobulins on the phosph atase activity of alkaline phosphatase in vitro. Bovine intestinal alk aline phosphatase was incubated with substrate in the presence of allo typic and xenotypic immunoglobulin. We found that bovine but not rabbi t immunoglobulin enhanced the phosphatase activity of bovine intestina l alkaline phosphatase. Similarly, human but not bovine immunoglobulin G enhanced human placental alkaline phosphatase activity. By enhancin g alkaline phosphatase activity, immunoglobulins bound to alkaline pho sphatase may assist physiologic transport functions and enhance resolu tion of the inflammatory response. Further, in clinical conditions wit h high immunoglobulin concentrations, the serum alkaline phosphatase r ecorded may have spuriously high values.