How can there be an abnormal CAP /CIP ratio when the PTH level is normal?
The normal range for the “intact” PTH assay within the normal population with functioning kidneys, is 10-65 pgm/mL. It has been learned that the ESRD patient population is associated with much higher levels of “intact” PTH assay values. The broad, somewhat arbitrary “intact” PTH range of approximately five times normal or 100-300 pgm/mL has been used as a rough target for PTH management in the ESRD population. However, it has been found that a patient with an “intact” PTH value of greater than 100 pgm/mL may have high, normal or adynamic low bone turnover status. We can use the 2nd generation “intact” PTH assay to predict the abnormality of adynamic low bone turnover ONLY if the “intact” PTH value is less than 100 pgm/mL. But we cannot use the “intact” PTH assay for renal bone status prediction if the value is greater than 100 pgm/mL. Therefore, if a patient has an “intact” PTH value of less than 100 pgm/mL, the ratio is not needed. If the “intact” PTH value is greater than 100 pgm/mL,
