Allogeneic hematopoietic stem cell transplantation favors altered hypothalamic dopaminergic tone

06-28-2006

Recent research from Mexico has reported on altered functional status of the hypothalamic dopaminergic tone in patients with chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

"We compared the functional status of the hypothalamic dopaminergic tone in patients given an allo-HSCT with chronic GVHD with that observed in patients with allo-HSCT without chronic GVHD and in healthy controls. The effect of acute dopaminergic blockade with intravenous metoclopramide on serum prolactin (PRL) concentrations was evaluated," wrote A. Parra and colleagues, Instituto Nacional de Perinatologia.

"Twenty volunteers, 20 to 52 years of age, seronegative for both hepatitis C virus and the human immunodeficiency virus, were studied: (1) 10 clinically healthy men (group 1), and (2) 9 patients with leukemia, and 1 patient with refractory aplastic anemia who underwent allo-HSCT, 5 of whom (3 men and 2 women) developed chronic GVHD (group 2), and 5 (3 men and 2 women) who did not develop chronic GVHD (group 3).

"Serum PRL concentrations were measured both fasting and after intravenous administration of metoclopramide (10-mg bolus). The area under the PRL curve was calculated. Patients in group 2 were older than those in groups 1 and 3 (p<.018), but their body mass index was similar," wrote the researchers.

"Fasting serum PRL concentrations were similar among the 3 groups; however, group 2 had higher PRL concentrations throughout the test (p<.001) and a greater area under the PRL curve than groups 1 and 3 (p<.001), without differences between the last 2 groups. The differences remained significant after adjustment for age (p<.01)," the investigators wrote.

The authors concluded, "Our results in a small group of patients with chronic GVHD after allo-HSCT suggest the existence of an increased functional level of their hypothalamic dopamine tone, which would favor a tendency toward a diminished endogenous production, release of pituitary PRL, or both. This could represent an adaptive mechanism aiming to maintain circulating PRL concentrations within a physiological range."

Parra and colleagues published their study in Biology of Blood and Marrow Transplantation (Altered functional status of the hypothalamic dopaminergic tone in patients with chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation: A pilot study. Biol Blood Marrow Transplant, 2006;12(5):566-572).

For additional information, contact A. Parra, Department of Endocrinology, Instituto Nacional de Perinatologia, Mexico City, Mexico.

The publisher of the journal Biology of Blood and Marrow Transplantation can be contacted at: Carden Jennings Publ Co. Ltd., Blake Center, Ste. 200, 1224 W Main St., Charlottesville, VA 22903, USA.

Keywords: Mexico City, Mexico, Graft-Versus-Host Disease, Hematopoietic Stem Cell Transplantation, Hepatitis C Virus, Transplantation Biology, Stem Cell Research.

This article was prepared by Clinical Trials Week editors from staff and other reports. Copyright 2006, Clinical Trials Week via NewsRx.com.