A predictive model for estimating the number of erythrocytapheresis or phlebotomy treatments for patients with naïve hereditary hemochromatosis

Item does not contain fulltextBACKGROUND AND AIMS: Standard treatment for naïve hereditary hemochromatosis patients consists of phlebotomy or a personalized erythrocytapheresis. Erythrocytapheresis is more efficient, but infrequently used because of perceived costs and specialized equipment being needed. The main aim of our study was to develop a model that predicts the number of initial treatment procedures for both treatment methods. This information may help the clinician to select the optimal treatment modality for the individual patient. METHODS: We analyzed retrospective data of 125 newly diagnosed patients (C282Y homozygous), treated either with phlebotomy (n = 54) or erythrocytapheresis (n = 71) until serum ferritin (SF) reached levels ≤100 μg/L. To estimate the required number of treatment procedures multiple linear regression analysis was used for each treatment method separately. RESULTS: The linear regression model with the best predictive quality (R(2)  = 0.74 and 0.73 for erythrocytapheresis and phlebotomy respectively) included initial SF, initial hemoglobin (Hb) level, age, and BMI, where initial SF was independently related to the total number of treatment procedures for both treatment methods. The prediction error expressed in RMSPE and RMSDR was lower for erythrocytapheresis than for phlebotomy (3.8 and 4.1 vs 7.0 and 8.0 respectively), CONCLUSIONS: Although the prediction error of the developed model was relatively large, the model may help the clinician to choose the most optimal treatment method for an individual patient. Generally erythrocytapheresis halves the number of treatment procedures for all patients, where the largest reduction (between 55% and 64%) is reached in patients with an initial Hb level ≥ 9 mmol/L (14.5 g/dL). ClinicalTrials.gov number NCT00202436

Erythrocytapheresis versus phlebotomy in the maintenance treatment of HFE hemochromatosis patients: results from a randomized crossover trial

Item does not contain fulltextBACKGROUND: Phlebotomy is standard maintenance treatment of patients with hereditary hemochromatosis (HH). Erythrocytapheresis, which selectively removes red blood cells, provides a new, potentially more effective treatment option. Our aim was to evaluate the effectiveness of erythrocytapheresis over phlebotomy for maintenance therapy in patients with HH. STUDY DESIGN AND METHODS: We conducted a two-treatment-arms, randomized, crossover clinical trial, involving 46 patients, treated for 1 year with either erythrocytapheresis or phlebotomy to keep the ferritin level at not more than 50 microg/L. After 1 year, patients were switched to the other treatment modality. Primary endpoint was the number of treatment procedures per treatment year. Secondary endpoints were intertreatment intervals, several aspects of health-related quality of life, costs, and patient discomfort as well as preference for one of both treatments. RESULTS: The mean number of required treatment procedures per treatment year was significantly higher using phlebotomy versus erythrocytapheresis (3.3 vs. 1.9; mean difference, 1.4; 95% confidence interval, 1.1-1.7). The median intertreatment time was 2.3 times longer for erythrocytapheresis. There was no significant difference in overall health assessed by SF-36 and EQ-5D, respectively, between both treatments arms. The number of self-reported swollen joints was significantly higher during phlebotomy treatment. The mean treatment costs of one treatment year were 235euro for phlebotomy versus 511euro for erythrocytapheresis. Eighty percent of patients preferred erythrocytapheresis as treatment method. CONCLUSION: Erythrocytapheresis significantly reduced the number of treatment procedures per treatment year, although the mean treatment costs per year are higher in our health care system. It is the preferred treatment for the majority of patients

Severe Ankyrin-R deficiency results in impaired surface retention and lysosomal degradation of RhAG in human erythroblasts

Ankyrin-R provides a key link between band 3 and the spectrin cytoskeleton that helps to maintain the highly specialised erythrocyte biconcave shape. Ankyrin deficiency results in fragile spherocytic erythrocytes with reduced band 3 and protein 4.2 expression. We use in vitro differentiation of erythroblasts transduced with shRNAs targeting the ANK1 gene to generate erythroblasts and reticulocytes with a novel ankyrin-R 'near null' human phenotype with less than 5% of normal ankyrin expression. Using this model we demonstrate that absence of ankyrin negatively impacts the reticulocyte expression of a variety of proteins including band 3, glycophorin A, spectrin, adducin and more strikingly protein 4.2, CD44, CD47 and Rh/RhAG. Loss of band 3, which fails to form tetrameric complexes in the absence of ankyrin, alongside GPA, occurs due to reduced retention within the reticulocyte membrane during erythroblast enucleation. However, loss of RhAG is temporally and mechanistically distinct, occurring predominantly as a result of instability at the plasma membrane and lysosomal degradation prior to enucleation. Loss of Rh/RhAG was identified as common to erythrocytes with naturally occurring ankyrin deficiency and demonstrated to occur prior to enucleation in cultures of erythroblasts from a hereditary spherocytosis patient with severe ankyrin deficiency but not in those exhibiting milder reductions in expression. The identification of prominently reduced surface expression of Rh/RhAG in combination with direct evaluation of ankyrin expression using flow cytometry provides an efficient and rapid approach for the categorisation of hereditary spherocytosis arising from ankyrin deficiency