Thyroid dysfunction in antiretroviral treated children

Background. A high rate of thyroid disorders has been described in HIV-infected adults treated with highly active antiretroviral therapy (HAART), but data on children are lacking. We aimed to assess thyroid function in pediatric patients. Methods. Fifty-two HIV-infected children receiving HAART were assessed for signs of thyroid dysfunction and serum concentrations of thyrotropin (TSH), free thyroxin (FT4), free triiodothyronine (FT3), thyroglobulin (TG), reverse triiodothyronine (rT3), anti-TG and antimicrosomal (anti-TSM) antibodies. Results. Eighteen (35%) children showed thyroid abnormalities: isolated low FT4 value in 16; subclinical hypothyroidism in 1; and symptomatic hypothyroidism in 1. Children with low FT4 values as compared with the 34 children without thyroid dysfunction were similar for stage of disease, number of patients with undetectable HIV-RNA, FT3, TSH, TG, rT3, anti-TSM and anti-TG values, whereas they had shorter duration of HAART exposure (P = 0.019) and lower CD4(+) cell percentage (P = 0.035). The thyrotropin-releasing hormone (TRH) test was normal in all children with low FT4 values. Among children with low FT4, FT4 concentrations correlated positively with CD4(+) cell percentage (P < 0.05) and duration of HAART exposure (P < 0.05). The case with subclinical hypothyroidism had high basal TSH (7.3 microunits/ml), normal TSH response to TRH test and normal FT4, FT3, TG, rT3, anti-TG and anti-TSM antibodies. The case with symptomatic hypothyroidism had low FT4 (6.6 pg/ml) and high TSH (44 microunits/ml), TG (55 ng/ml), anti-TG (666 IU/ml) and anti-TSM (123 IU/ml). Conclusion. Thyroid abnormalities occur frequently in HAART-treated children even in the absence of clinical symptoms. These data suggest a need of regular thyroid function monitoring.