Circulating immonoglobulin M: increased concentrations in endemic and sporadic goiter

Increased concentrations of immunoglobulin M have been found in the circulation of approximately half of patients with either endemic or sporadic nontoxic goiter. Blood was obtained from patients in several iodine-deficient goitrous areas; the patients with sporadic goiter resided in or about New York City. Concentrations of immunoglobulins G, A, and D were normal. Blood for control purposes was taken from patients residing in cities near the goiter areas where there was no iodine deficiency, and in New York City. Most of these samples came from hospitalized patients without known thyroid disease and were collected at random. Chi-square values for the difference between the number of goitrous patients with elevated concentrations of immunoglobulin M and those in the control patients were highly significant statistically.