Somatostatin receptor expression in clinical immunology

Specific somatostatin receptors (ssts) have been described in normal and tumor tissues and identified on more than 95% of normal mitogen-activated human peripheral lymphocytes. Somatostatin may modulate the immune response by a variety of mechanisms, most of which are inhibitory, sst scintigraphy in patients with immune-mediated diseases revealed sst expression in 97% of patients with sarcoidosis, 100% of patients with tuberculosis or Wegener's granulomatosis, 75% of patients with Sjogren's syndrome, and 50% of patients with systemic:lupus erythematosus or uveitis, sst expression appeared to be related to progression or remission of disease. Patients who responded poorly to therapy remained positive at scintigraphy. Investigation of 10 human B-cell lines and eight human T-cell lines, using a polymerase chain reaction, revealed the presence of sst(2)-mRNA in two of the B-cell and two of the T-cell lines. Visualization of ssts on activated mononuclear leukocytes by sst scintigraphy may prove useful in evaluating the spread of immune-mediated diseases and their responses to therapy. The efficacy of octreotide should be studied in patients with these diseases. Copyright (C) 1996 by W.B. Saunders Company