Tartarate Resistant Acid Phosphatase (TRAcP/TRAP5) [ACP5/1070]

Tartrate resistant acid phosphatase (TRAcP) is a basic, iron-binding protein with high activity towards phosphoproteins, ATP and 4 nitrophenyl phosphate. Expression of TRAcP is reported to be increased in the spleen and monocytes of individuals with Gaucher’s disease, splenocytes and circulating white cells of individuals with hairy cell leukemia, spleens of individuals with Hodgkin disease, and the sera of individuals undergoing active bone turnover. Elevated levels are also reported to be associated with various B-cell and T-cell leukemias and lymphomas, placental decidual cells, syncytiotrophoblasts, and some macrophages distributed throughout maternal and embryonic tissues. The histochemical identification of hairy cell leukemia via tartrate-resistant acid phosphatase assay has been a standard for over two decades. Anti-TRAcP labels the cells of hairy cell leukemia (HCL) with a high degree of sensitivity and specificity. Worthy also of mention in this regard are anti-annexin A1 and anti-CD11c. Other cells stained with anti-TRAcP are tissue macrophages and osteoclasts, which also express abundant TRAcP activity.