[Change in serum G-CSF levels in patients with Graves' disease by treatment with methimazole]

We evaluated the determination of serum G-CSF in the diagnosis of granulocytopenia due to methimazole (MMI) in 54 patients with Graves' disease, while they were being treated with MMI, by way of measuring WBC counts and serum levels of G-CSF, thyroid hormones, IgE, and interleukin-2. Serum TSH was measured by immunoradiometric assay, serum G-CSF was done by enzyme immunoassay, thyroid hormones and IgE were done by radioimmunoassay, and serum Interleukin-2 was done by enzyme-linked immunosorbent assay. The population whose G-CSF levels were higher than the minimum detectable level (30pg/ml) was 6 (30%) in normal subjects, 4 (22%) in patients with untreated Graves' disease, 2 (12%) in patients with treated euthyroid Graves' disease, 3 (23%) in patients with Graves' disease who had gone through agranulocytosis, and 2 (33%) in patients with Graves' disease complicated with granulocytopenia. There was no significant change in WBC counts for 4 weeks, but there was a significant difference between WBC counts before treatment and those at 8 weeks after treatment. We observed no significant change of serum G-CSF levels in patients with Graves' disease under treatment. However, there were significantly high levels of serum G-CSF and significantly low counts of WBC in patients with Graves' disease complicated with granulocytopenia induced by MMI, compared with those in normal subjects, patients with untreated Graves' disease, patients with treated euthyroid Graves' disease, and patients with euthyroid Graves' disease who had gone through agranulocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)