Dysregulation of the hypothalamo-pituitary axis in rheumatoid arthritis

J Rheumatol. 1995 Oct;22(10):1829-33.


Objective: To study the dynamic response of the hypothalamo-pituitary- adrenal axis and of prolactin (PRL) pituitary secretion in rheumatoid arthritis (RA).

Methods: We performed a cortisol releasing hormone (CRH) provocation test followed by determination of adrenocorticotropin hormone (ACTH), beta-endorphin, and cortisol concentration, and then a thyrotropin releasing hormone (TRH) provocation test followed by assessment of PRL pituitary secretion in 10 patients with RA and 5 control subjects. All were women under 40 years of age. Hormone concentrations were assessed by radioimmunoassay.

Results: Basal PRL cortisol, and ACTH concentrations were similar in patients with RA and controls. We observed a dissociation between the pituitary secretion of beta-endorphin and of ACTH in response to CRH in RA. The ACTH peak and total ACTH production (area under the curve, AUC) were similar in the 2 groups. In contrast, basal beta-endorphin was increased in RA (12.6 +/- 1.41 vs 8.29 +/- 0.144 pg/ml), and the response upregulated (AUC: 83,080 +/- 12,000 vs 54,200 +/- 2400) after CRH compared to controls (p < 0.05). Cortisol adrenal response curve was blunted, but did not reach statistical significance. In contrast, the PRL response to TRH was increased at 120 and 150 min (3461 +/- 303 vs 1897 +/- 520 muIU/ml)(p < 0.01) in patients with RA, independent of disease activity.

Conclusion: We observed upregulated pituitary PRL secretion in RA, and a dissociation of ACTH stress. The implication concerning the neuroendocrine system in the chronic immune response in RA is discussed.

MeSH terms

  • Adrenocorticotropic Hormone / blood
  • Adult
  • Animals
  • Arthritis, Rheumatoid / blood
  • Arthritis, Rheumatoid / physiopathology*
  • Corticotropin-Releasing Hormone / pharmacology
  • Female
  • Humans
  • Hydrocortisone / blood
  • Hypothalamo-Hypophyseal System / physiopathology*
  • Prolactin / blood
  • Radioimmunoassay
  • Reference Values
  • Sheep
  • Thyrotropin-Releasing Hormone / pharmacology
  • beta-Endorphin / blood


  • Thyrotropin-Releasing Hormone
  • beta-Endorphin
  • Adrenocorticotropic Hormone
  • Prolactin
  • Corticotropin-Releasing Hormone
  • Hydrocortisone