Pancreatic stone protein (PSP)

Pancreatic stone protein (PSP), also termed regenerating protein 1 (Reg I) or PSP/reg, is a C-type lectin-like protein of approximately 14–16 kDa mainly secreted by pancreatic acinar cells, and structurally similar to other calcium-dependent glycan-binding proteins[1][3][4]. Initially identified as an inhibitor of calcium carbonate precipitation in pancreatic juice and implicated in the formation of pancreatic stones in chronic pancreatitis, it has since been recognized for more complex biological activities. PSP is an acute-phase reactant—its synthesis and secretion increase in the pancreas and some other tissues (including brain) in response to systemic stress, distant organ injury, inflammation, and infections such as sepsis[1][3][6]. PSP is not considered a traditional therapeutic target (like receptor or enzyme), but serves as a clinically validated biomarker used for early diagnosis, prognosis, and severity assessment of bacterial infections and sepsis, including in emergency, ICU, and pediatric settings[5][6][7]. It is also involved in innate immune responses, may modulate neutrophil activation, and serves as a potential indicator of beta cell ER stress in metabolic diseases[1][3][4]. PSP's diagnostic accuracy and rapid change upon infection make it an attractive point-of-care biomarker, though no drugs are known to target it directly, and there are no reported safety concerns as it is used for monitoring, not therapy[5][6].

Other names

lithostathineregenerating protein 1 (Reg I)PSP/regReg