Test for monitoring
efficacy of therapy for cancer and certain viral infections
The test measures the activity of an enzyme α-N-acetylgalactosaminidase (nagalase) in blood.
Nagalase is an extracellular matrix-degrading enzyme that is secreted by cancerous cells in the process of tumor invasion. it is also secreted from virus-infected cells such as HIV and influenza.
Nagalase deglycosylates the vitamin D3-binding protein DBP (Gc-protein), which is the precursor for the major macrophage-activating factor (MAF). By complete deglycosylation, Gc-protein can no longer be converted to MAF. Since macrophage activation for phagocytosis and antigen presentation is the first stepp in the immune cascade, loss of precursor activity via increased nagalase, leads to immune suppression.
Increased nagalase activity has been detected in the blood of patients with a wide variety of cancers like cancer of the prostate, breast, colon, lung, oesophagus, stomach, liver, pancreas, kidney, bladder, testis, uterus, and ovary, mesothelioma, melanoma, fibrosarcoma, glioblastoma, neuroblastoma, and various leukemias. Increased nagalase activity has not been detected in the blood of healthy individuals.
Nagalase activity is directly proportional to viable tumor burden. Studies correlating nagalase levels with tumor burden suggest that the measurement of this enzyme can diagnose the presence of cancerous lesions below levels detectable by other diagnostic means. In research studies, nagalase activity decreased to near tumor-free control levels one day after surgical removal of primary tumors from cancer patients, suggesting that the half-life of nagalase is less than 24 hours. The short half-life of nagalase is valuable for prognosis of the disease during various therapies.
Activity of α-N-acetylgalactosaminidase (Nagalase) in serum or plasma is determined through a proprietary method consisting of a two step immunocapture assay.