[Thyroid dysfunction after haematopoietic stem cell transplantation during childhood].
To evaluate the percentage and risk factors of thyroid dysfunction in 79 children who underwent bone marrow transplantation in a single centre.


METHODS
The mean age of the cohort was 6.8 and mean follow-up 5.5 years. The 79 patients were divided in two groups according to the pretransplant conditioning regimen: fractionated total body irradiation (TBI)(N=54), chemotherapy with Busulphan (N=25). Thyroid function was evaluated by thyroid-stimulating hormone (TSH) and free thyroxine (fT4) tests. Overt hypothyroidism was defined by low fT4 blood levels and TSH > 4 mU/l, and compensated hypothyroidism by normal fT4 index and TSH >4 mU/L.


RESULTS
The six-year probability of hypothyroidism was 36 +/-6% for the whole group of 79 patients, 49 +/-8% after TBI and 9 +/-6% in the Busulphan group (P <0.001). Neither gender, nor primary disease, nor presence of graft versus host disease were found to be statistically significant for occurrence of hypothyroidism in the TBI group. However, a younger age seemed to influence statistically the 6-year probability of hypothyroidism in the TBI group: 59 +/-9% if age <7.7 years versus 34 +/-13% if age >7.7 years (P =0.02).


CONCLUSIONS
A careful follow-up of thyroid function is recommended even without TBI conditioning regimen. Young age as a potential risk factor of hypothyroidism has never been described and needs to be studied in a larger cohort.
Curtillet
C
C
Service hématologie pédiatrique du professeur Michel, hôpital Timone-Enfants, 264, rue Saint-Pierre, 13385 Marseille cedex 05, France. Catherine.Curtillet@mail.ap-hm.fr
Cuadras
P
P
Dore
E
E
Chambost
H
H
Thuret
I
I
Michel
G
G
D000293:Adolescent; D000367:Age Factors; D016026:Bone Marrow Transplantation / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology*; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000628:therapy; D012307:Risk Factors; D014916:Whole-Body Irradiation / Q000009:adverse effects