Thyroid Research Thyroid Research Archive Autoimmune Thyroid Disease

Patients with chronic hepatitis C infection often have thyroid disorders

(November 2004)

The background of the study. Patients with chronic hepatitis C virus infection may have manifestations of autoimmune thyroid disease, but whether this occurs more often than in normal subjects is unclear. In this study the frequency of thyroid disorders was evaluated in patients with hepatitis C, patients with chronic hepatitis B, and normal subjects.

How the study was done. The study subjects were 630 patients with chronic hepatitis caused by hepatitis C virus infection, 86 patients with chronic hepatitis caused by hepatitis B virus infection, 389 normal subjects who lived in the same area of Italy, in which iodine intake is relatively low, and 268 normal subjects who lived in an area of higher iodine intake. The study subjects underwent a clinical examination and had measurements of serum thyrotropin (TSH), free thyroxine (T4), and antithyroid peroxidase (anti-TPO) antibodies.

The results of the study. The sex and age of the patients in the four groups were similar. The average serum TSH and anti-TPO antibody concentrations were higher and the serum free T4 concentrations were lower in the patients with chronic hepatitis C than in the other three groups (Table).

Table. Average Serum TSH, Free T4, and Anti-TPO Antibody (Ab) Concentrations in the Four Study Groups.
Serum Values	Hepatitis C	Hepatitis B	Normal, I-Deficient	Normal, I-Sufficient
	(n = 630)	(n = 86)	(n = 389)	(n = 268)
TSH (mU/L)	3.2	1.7	1.5	1.3
Free T4 (ng/dl)**	0.8	0.9	1.0	0.9
Anti-TPO Ab (U/ml)	127	51	42	47
No. (%) with high values	132 (21)*	11 (13)	47 (12)	27 (10)

The serum concentrations of both antibodies were high in 21 percent of the patients with chronic hepatitis C, as compared with 10 to 13 percent of the patients in the other three groups.

The conclusions of the study. Thyroid dysfunction and autoimmunity is more common in patients with chronic hepatitis C than in patients with chronic hepatitis B or normal subjects.

The original article. Antonelli A, Ferri C, Pampana A, Fallahi P, Nesti C, Pasquini M, Marchi S, Ferrannini E. Thyroid disorders in chronic hepatitis C. Am J Med 2004;117:10-13.