Treatment of Hemochromatosis

Hereditary hemochromatosis (HH) occurs in 1 in every 200-250 individuals of northern European descent, and is the most common inherited disease in this population. Although the molecular pathophysiology remains incompletely understood, a homozygous mutation in the HFE gene (Cys282Tyr) is observed in nearly 100% of clinically confirmed cases. The clinical manifestations of HH are due to inappropriately increased iron absorption with excessive iron deposition in the liver, heart, endocrine organs, and joints. Phlebotomy treatment, with removal of iron contained in the hemoglobin of red cells, is the only effective therapy for HH. Phlebotomy therapy relieves many of the symptoms of iron-mediated tissue damage and prevents progression to cirrhosis. However, published laboratory guidelines for monitoring phlebotomy therapy are based on retrospective data, and in general allow a moderate level of iron overload to persist during maintenance therapy. Since 1987, the DTM has piloted the use of the red cell mean corpuscular volume (MCV), in conjunction with the hemoglobin, as a prospective guide to phlebotomy therapy in a small cohort of HH patients. In contrast to other retrospectively-derived guidelines, this simple, inexpensive, physiologic method was found to be a precise indicator of iron-limited erythropoiesis, and could be easily applied to adjust the pace of phlebotomy and prevent excess iron reaccumulation. Although the majority of persons with HH meet eligibility criteria for allogeneic blood donation, until recently regulatory guidelines restricted the use of therapeutically withdrawn blood for transfusion. New regulations now permit increased flexibility in the use of such units for this purpose. The purposes of this protocol are: (1) to prospectively study the genotypic and phenotypic response to phlebotomy therapy in HH patients using the MCV/hemoglobin monitoring guide, and to validate the use of this guide in a large study cohort; (2) to evaluate the course of severe hepatic disease and rheumatologic symptoms following sustained iron depletion; and (3) to establish the safety and efficacy and document the operational issues inherent in a program to collect therapeutically withdrawn blood for use in allogeneic transfusion. These goals have as their combined target the establishment of the simplest, safest system for donor processing, phlebotomy management, and transfusion of blood drawn from HH subjects.