Elevated serum interleukin-6 and decreased thyroid hormone levels in postoperative patients and effects of IL-6 on thyroid cell function in vitro.
We studied a wide variety of surgical patients to determine whether serum levels of interleukin-6 (IL-6) or tumor necrosis factor-alpha (TNF-alpha) correlate with the changes in serum thyroid hormone levels of the postoperative period. Surgical procedures were divided into minor surgery (cholecystectomy, n = 12), moderate surgery (colorectal cancer and stomach cancer, n = 54), and extensive surgery (esophageal cancer or pancreatic cancer, n = 6). One day after surgery, serum free T3 levels decreased in all 3 groups when compared to the preoperative values; serum free T4 levels did not change regardless of surgical procedure. Serum TSH levels decreased significantly 1 day after surgery in the groups of moderate and extensive surgery. Serum levels of IL-6 increased 12 h after surgery and began to decrease gradually thereafter. There was no change in serum levels of TNF-alpha before and after surgery. The increment of serum IL-6 was dependent on the surgical procedures: the more extensive the surgery, the greater the increase in serum IL-6. Serum free T3 and free T4 levels were inversely correlated with the serum levels of IL-6. To further examine whether IL-6 is responsible for alteration of thyroid hormone production, cultured porcine thyroid follicles were exposed to 0 to 20 ng/ml of recombinant human IL-6 for 24 to 48 h. Then, type 1 5'-deiodinase activity (T4 to T3 converting enzyme), iodide uptake, and thyroid peroxidase (TPO) activity were measured. Our in vitro experiments showed no effect of IL-6 on these parameters. In summary, surgical procedure can cause elevation of serum IL-6 and decrease in serum free T3 levels. However, IL-6 alone does not appear to be a strong candidate for alteration of thyroid hormone production including T3 generation from T4.
Murai
H
H
The Second Department of Surgery, Saitama Medical School, Japan.
Murakami
S
S
Ishida
K
K
Sugawara
M
M
D000368:Aged; D002763:Cholecystectomy; D015179:Colorectal Neoplasms / Q000601:surgery; D004938:Esophageal Neoplasms / Q000601:surgery; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism* / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000601:surgery; D011184:Postoperative Period; D013274:Stomach Neoplasms / Q000601:surgery; D013514:Surgical Procedures, Operative; D013961:Thyroid Gland / Q000503:physiopathology*; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D015850:Interleukin-6; D013963:Thyroid Hormones; D014409:Tumor Necrosis Factor-alpha; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine