TRANSPLANTATION OF HUMAN CRYOPRESERVED ADENOMATOUS AND HYPERPLASTIC PARATHYROID TISSUE TO THE HYPOCALCEMIC NUDE-MOUSE

Cryopreserved parathyroid glands from patients operated on for hyperpa rathyroidism were stored for further auto- or allografting. In an atte mpt to better use cryopreserved parathyroid glands in humans, we desig ned a study whose goal was to compare human parathormone (hPTH) secret ion from cryopreserved parathyroid glands with regard to tissue histol ogy (adenoma or hyperplasia), mass, and time of storage in hypocalcemi c Nude mice and to be able to better use them in humans. A new hypocal cemic experimental model, using parathyroidectomized Nude mice was set up. Hypocalcemic mice received calibrated grafts from human parathyro id glands cryopreserved between.1982 and 1992 originating from 30 pati ents (15 adenomas, 15 hyperplasias). Each parathyroid was grafted into two mice under the ratio of one mass-unit (12 mg) and three mass-unit s (36 mg). The hPTH concentration was assessed by an immunoradiometric method 21 days after grafting. The mean cryopreservation time was 677 days (54-3187 days). The time of cryopreservation was identical in th e two kinds of tissue (p = 0.88). The hPTH concentration in 59 living mice was 72.2 +/- 271.4 (SD) ng/ml (3-1936 ng/ml). This concentration was 7.1 +/- 4.3 ng/L for adenomas versus 139.4 +/- 378.6 ng/L for hype rplasias (p = 0.003) and 87.1 +/- 352.6 ng/L for one-unit-mass grafts versus 56.7 +/- 152.5 ng/L for three unit-mass grafts (p = 0.824). Hyp erplastic glands showed more secretion, which was confirmed in both ma ss related groups (p = 0.02, p = 0.006). The multiple linear regressio n showed no hPTH concentration difference related to mass or time of c ryopreservation (p > 0.15), and it confirmed that the highest secretio n of hPTH was in the hyperplastic tissues (p = 0.0001). These results show that cryopreservation preserves glands for several years, and tha t hyperplastic tissue preferentially should be used.