Decreased immunoreactive beta‐endorphin in mononuclear leucocytes from patients with rheumatic diseases
The ncuroendocrine potypeptide hormone beta‐endorphin (β‐END), which is released from various tissues including the anterior pituitary gland and cells of the immune system, has recently been implicated as having an immunoregulalory role. We used a radioimmunoassay to measure β‐END levels in circulating mononuclear leucocytes from normal subjects and patients with various rheumatic diseases. Levels of β‐END in leucocytes from patients were lower than in leucocytes from healthy subjects (P<0.001). Whereas levels of β‐END in leucocytes from patients with the various rheumatic disorders were not significantly different, an inverse correlation was found between β‐END levels in leucocytes and expression of rheumatoid factor (P<0.025) and erythrocyte sedimentation rate (P<0.025). This study demonstrates decreased content of β‐END in cells of the immune system related to parameters of inflammatory activity in rheumatic diseases.