Peculiarities of Graves' disease in children and adolescents with Down's syndrome.
OBJECTIVE
To compare the presentation and clinical course of Graves' disease (GD) in two pediatric populations consisting of 28 patients with Down's syndrome (DS) and 109 controls without DS respectively.


METHODS
The evolution over time of GD was determined in both groups according to the clinical changes and the variations in TSH, free thyroxine, and TSH receptor autoantibodies serum levels during the entire follow-up.


RESULTS
Female prevalence (50 vs 81.6%; chi(2)=12.0, P<0.0005) and average age at GD presentation (9.9+/-4.4 vs 11.5+/-3.5 years, P<0.05) were significantly lower in DS group than in controls. Clinical responsiveness to methimazole therapy was significantly better in DS patients, as demonstrated by both the lower relapse rates after the first cycle withdrawal (7.1 vs 31.2%; chi(2)=7.4, P<0.005) and the higher persistent remission rates after definitive therapy withdrawal (46.4 vs 26.7%; chi(2)=4.1, P<0.05). Moreover, in DS group, no patients needed surgery or radioiodine ablation, whereas non-pharmacological treatment was necessary in 11% of controls (chi(2)=3.8, P<0.05). Antecedents of Hashimoto's thyroiditis (HT) were documented in 21.4% of DS patients and in 3.7% of controls (chi(2)=10.4, P<0.005). Association with other autoimmune diseases was detected in 32.1% of DS cases and in 12.8% of controls (chi(2)=5.94, P<0.025).


CONCLUSIONS
GD in DS children and adolescents is characterized by several peculiarities: i) earlier presentation; ii) no gender predominance; iii) less severe clinical course; iv) higher frequency of documented HT antecedents; v) more frequent association with other autoimmune diseases.
De Luca
Filippo
F
Department of Pediatrics, University of Messina, 98124 Messina, Italy.
Corrias
Andrea
A
Salerno
Mariacarolina
M
Wasniewska
Malgorzata
M
Gastaldi
Roberto
R
Cassio
Alessandra
A
Mussa
Alessandro
A
Aversa
Tommaso
T
Radetti
Giorgio
G
Arrigo
Teresa
T
D000293:Adolescent; D017668:Age of Onset; D013956:Antithyroid Agents / Q000627:therapeutic use; D016009:Chi-Square Distribution; D002648:Child; D018450:Disease Progression; D004314:Down Syndrome / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006111:Graves Disease / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D018579:Patient Selection; D015995:Prevalence; D012720:Severity of Illness Index; D012737:Sex Factors; D018709:Statistics, Nonparametric
D013956:Antithyroid Agents; D008713:Methimazole