T. Pasqualini et al., HYPOTHALAMIC-PITUITARY THYROID ABNORMALITIES IN CHILDREN AFTER RENAL-TRANSPLANTATION, Pediatric nephrology, 10(5), 1996, pp. 621-624
Patients with a successful renal transplant may have abnormalities in
thyroid function. We evaluated serum thyroid hormone levels, serum thy
rotropin (TSH) response to thyrotropin-releasing hormone (TRH), and th
e circadian pattern of serum TSH in 18 children aged 6.6-19.4 years (m
edian 12.6 years), 4.0 +/- 2.9 years after renal transplantation. In 1
4 children, immunosuppressive therapy included methylprednisone [mean
(+/- SD) 0.17 +/- 0.05 mg/kg per day], while in 11 it included deflaza
cort (0.32 +/- 0.1 mg/kg per day). Seven children were studied twice,
under methylprednisone and again while on deflazacort therapy. Mean to
tal and free thyroxine (T4) values were significantly below the mean c
ontrol levels (total T4 108.5 +/- 21.5 vs. 118.7 +/- 22.1 nmol/l, P <0
.05 and free T4 14.4 +/- 4.0 vs. 18 +/- 4.9 pmol/l, P <0.001). Morning
basal TSH levels were within the normal range. The mean TSH increment
after TRH was 4.4 +/- 3.5 mU/l, significantly lower than that of cont
rols (10.8 +/- 4.26, P <0.001). Of 7 patients on methylprednisone, 4 h
ad nocturnal TSH surges below the normal range (95% confidence limits
47%-300%); this occurred in 3 of 8 patients on deflazacort therapy. Th
e TSH response to TRH was correlated with deflazacort dose. Patients o
n methylprednisone and deflazacort therapy had similar thyroid alterat
ions. Our findings support the hypothesis that after renal transplanta
tion some children have hypothalamic-pituitary thyroid abnormalities i
n which glucocorticoids may play a significant role.