Elevated serum granulocyte colony-stimulating factor levels in patients with Graves' disease.
OBJECTIVE
Agranulocytosis is a serious side effect of anti-thyroid drugs (ATD). Granulocyte colony-stimulating factor (G-CSF) is one of the cytokines that increase granulocyte number. The aim of this study was to examine the sequential variation of serum G-CSF levels in patients with Graves' disease before and after ATD therapy.


METHODS
Sixty-three patients with Graves' disease were studied before, during and after treatment with methimazole (MMI). Serum samples from 71 healthy subjects were used as controls.


METHODS
Serum levels of G-CSF were measured by a novel chemiluminescent enzyme immunoassay, which was sensitive enough to determine G-CSF levels in healthy subjects. Blood granulocyte counts, serum, thyroid hormone and TSH levels, and titres of thyroid autoantibodies were also measured.


RESULTS
Serum G-CSF levels in Graves' patients before and 2 weeks after MMI were significantly higher than in healthy subjects. There was a significant correlation between serum G-CSF levels and granulocyte counts in untreated patients with Graves' disease. Untreated patients with granulocyte counts less than 2 x 10(9)/I had significantly lower serum G-CSF levels as compared with other untreated patients. Serum G-CSF levels gradually decreased thereafter. No correlation was observed between serum G-CSF levels and serum thyroid hormone levels or titres of thyroid autoantibodies. After ATD treatment, no correlation was found between serum G-CSF levels and granulocytes counts. There was no significant correlation between the change of serum G-CSF levels and that of granulocyte counts before and after MMI treatment. Graves' patients with mild agranulocytosis had normal or elevated serum G-CSF levels.


CONCLUSIONS
Significantly elevated serum G-CSF levels were observed in patients with Graves' hyperthyroidism. During ATD therapy, deficiency of G-CSF was not identified as a cause of agranulocytosis in this study.
Iitaka
M
M
Department of Internal Medicine 4, Saitama Medical School, Japan.
Noh
J Y
JY
Kitahama
S
S
Fukasawa
N
N
Miura
S
S
Kawakami
Y
Y
Kawasaki
S
S
Yamanaka
K
K
Ishii
J
J
Katayama
S
S
Ito
K
K
D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use*; D001323:Autoantibodies / Q000097:blood; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood*; D006098:Granulocytes / Q000378:metabolism; D006111:Graves Disease / Q000097:blood* / Q000188:drug therapy / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D007958:Leukocyte Count; D008163:Luminescent Measurements; D008297:Male; D008713:Methimazole / Q000627:therapeutic use*; D008875:Middle Aged; D013963:Thyroid Hormones / Q000097:blood
D013956:Antithyroid Agents; D001323:Autoantibodies; D013963:Thyroid Hormones; D016179:Granulocyte Colony-Stimulating Factor; D008713:Methimazole