Background. The causes of secondary hyperparathyroidism (HPT) in end stage renal disease (ESRD) are supposed to disappear after renal transplantation (RT) if the graft function is adequate; however the regression of HPT often takes a long time. Our aim was to evaluate the role of the duration of dialysis in the outcome of parathyroid function after RT in children.

Subjects. The study was based on data from Ca-P metabolism before RT and over a 90 day period after RT in 41 children (16 girls, 37 cadaver donors), with a mean age of 9.6 yrs [0.7-17.2].

Intervcentions. Patients were divided into: group I, pre-emptive RT (n=17), and group II, dialysis prior to RT (n=24). Groups were matched for age, sex, duration of ischemia and CyA trough blood level. Values are given as mean±SD.

Results. No significant difference was seen with regard to all assessments of serum Ca, P, 250H-D, Mg and tubular tests between the 2 groups. Results of PTH and inulin clearance are depicted below.Table

Table 1

Conclusion. The difference of PTH level before RT is due to the shorter duration of ESRD in group I; however the reasons for such an ongoing difference after 90 days are not clear. Graft dystunction is unlikely, since glomerular and tubular tests are similar. It seems that a period longer than 3 months is mandated for normalization of PTH production if severe HPT has occurred before RT. Skeletal resistance to PTH, low density of calcitnol receptor in parathyroid gland and/or nodular rather than diffuse hyperplasia of the gland could be speculated to explain such conclusions.