Effects of parathyroid hormone and serum calcium on the phenotype and function of mononuclear cells in patients with primary hyperparathyroidism.

Background: Several studies have demonstrated specific influence of parathyroid hormone (PTH) on immune parameters, especially on T- and B-cell function, migration of polymorphonuclear leucocytes (PMNLs) and antibody synthesis, in patients with secondary hyperparathyroidism and chronic renal failure and recently also in patients with primary hyperparathyroidism (pHPT).

Methods: We therefore examined 12 patients with pHPT before and 6 months after parathyroidectomy (PTX) and nine sex- and age-matched control subjects to determine the impact of PTH and serum calcium concentrations on several immune parameters, including (a) serum concentrations of immunoglobulins, (b) immunophenotype of peripheral blood lymphocytes, (c) phytohaemagglutinin (PHA)-induced lymphocyte proliferation and (d) monocytic surface marker expression.

Results: Serum concentrations of immunoglobulins (IgG, IgA, IgM) were unaffected by elevated serum PTH and calcium levels.

Effect of elevated growth hormone concentrations on the phenotype and functions of human lymphocytes and natural killer cells.

Over the past decades, strong evidence has accumulated that growth hormone (GH) has immunostimulatory properties. Therefore, an investigation was conducted on 10 acromegalic patients and 9 age- and sex-matched healthy controls to determine whether plasma GH concentrations correlate with changes in several immune parameters, including serum concentrations of immunoglobulins, lymphocyte subsets, lymphocyte transformation with phytohemagglutinin (PHA), natural killer (NK) cell activity as well as phagocytic and metabolic burst activity. While NK cell activity, serum concentrations of immunoglobulins (IgG, IgM, IgA) and metabolic burst activity were within the normal range in both groups, a significantly enhanced phagocytic activity was observed in the acromegalic patients.

Interferon-alpha stimulates the hypothalamic-pituitary-adrenal axis in vivo and in vitro.

The successful therapeutic use of interferon-alpha (IFN-alpha) in myeloproliferative disorders offered the possibility to test its acute and long-term effects on the hypothalamic-pituitary-adrenal (HPA) axis in humans. ACTH and cortisol plasma concentrations were measured in 8 patients hourly starting from 4 p.m.

Effect of recombinant human erythropoietin on anterior pituitary function in patients on chronic hemodialysis.

In 7 patients with end stage renal failure, anterior pituitary function was tested by simultaneous application of maximally effective doses of the hypothalamic releasing peptides, corticotropin-releasing hormone, growth hormone-releasing hormone, thyrotropin-releasing hormone and gonadotropin-releasing hormone, and compared to 8 normal controls. In addition to the pituitary hormones, plasma cortisol, thyroxine and testosterone concentrations were measured. To test for possible effects of treatment with recombinant human erythropoietin (rhu-EPO), all patients with chronic renal failure were studied again after partial correction of anemia by treatment with erythropoietin.