Immunological characterization of pancreatic stone protein in human urine

In order to study the mechanism and origin of urine pancreatic stone protein (PSP), PSP was analyzed in the urine and sera from healthy subjects, patients with renal disease, and intensive care patients by Mono S chromatography and Western blotting. The elution patterns could be classified into three types. In control urine, a single peak of immunoreactive PSP (peak I) was identified at the position of PSP-S2-5 (type A). In three of seven patients with renal disease, another peak of urine immunoreactive PSP (peak II) was recognized at the position slower than that corresponding to that of PSP-S1 (type B). In urine from one patient with diabetic nephropathy, a third peak of immunoreactive PSP (peak III) was eluted between peaks I and II (type C). In Western blotting, the bands in urine from patients with renal disease and of those in ICU mainly appeared at the positions of high-molecular-weight types of PSP and PSP-S2-5, respectively. These results suggest that the kidney can be another major source of urine PSP in addition to the pancreas.