Macro lipase--a new member of the family of immunoglobulin-linked enzymes.

This first report describes a variant form of lipase in the serum of a woman suffering from a malignant non-Hodgkin lymphoma. Activity measurements of serum lipase and amylase showed persistently elevated activities of lipase with simultaneously normal activities of amylase. Results of exclusion chromatography and immunological investigations clearly demonstrate that the atypical time-course of lipase activity is not due to injury of the pancreas or alterations of the patient's lipase, but rather due to the presence of lipase-binding autoantibodies, resulting in the formation of immune complexes with high molecular mass (Mr greater than 200,000) between lipase and immunoglobulin G lambda. A clinical significance, if any, of this macro lipase has yet to be determined.