Alkaline phosphatase (ALP) is known to cross-react with 5'-nucleotidase (5'NT) measurements. Placental ALP of 100 U/L gives a 5'NT result of 0.27 U/L. Accordingly, specimens with elevations of any ALP isoenzyme significantly above normal circulating activity must be interpreted cautiously.
5'-nucleotidase is neither specific nor sensitive enough to be used as a cancer screen.
Do not interpret serum 5' NT activity as absolute evidence of the presence or the absence of malignant disease. Use serum 5' NT in conjunction with information from the clinical evaluation of the patient and other diagnostic procedures.
Values obtained with different assay methods or kits may be different and cannot be used interchangeably.