Susana Rocha

Hepcidin Serum Levels and Resistance to Recombinant Human Erythropoietin Therapy in Haemodialysis Patients

This title was also presented orally at Clinical Biochemistry workshop,Faro, 29 Janeiro, 2010

Protein deficiency balance as a predictor of clinical outcome in hereditary spherocytosis

Abstract:u2002 Vertical and horizontal interactions between membrane constituents account for integrity, strength and deformability of the erythrocyte. Disruption of vertical interactions caused by membrane protein deficiencies in hereditary spherocytosis (HS), favor membrane vesiculation with development of spherocytic cells. Our aim was to evaluate the hematological and clinical presentation of HS according to the type and amount of protein deficiency. We studied 81 Portuguese individuals, 71 belonging to 21 families plus 10 unrelated subjects, and found that 51 of them were HS patients. Patients were classified as presenting mild, typical or severe HS, according to laboratory results and clinical follow‐up. We performed screening tests and the standardized electrophoretic membrane protein analysis to identify and quantify protein deficiencies. We found band 3 and ankyrin deficiencies as the major causes for HS. The ratios between the value of the primary and/or secondary protein deficiencies showed significantly different values according to the severity of HS, and a significant inverse correlation with the severity of HS was observed. In mild HS, the ratios between protein deficiencies reflected equivalent protein deficiencies, while an unbalance was observed in typical HS, which was enhanced in severe HS. Our data suggest that the relative quantification of each major membrane protein and of the ratios between the values of protein deficiencies may be helpful in providing additional data about the clinical outcome of HS.

Changes in Red Blood Cells Membrane Protein Composition during Hemodialysis Procedure

Our aim was to evaluate the influence of the hemodialysis (HD) procedure in red blood cells (RBC) membrane protein composition. We evaluated hematological data (RBC count, hemoglobin concentration, and hematimetric indices) and RBC membrane protein composition (linear and exponential gradient polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate [SDS-PAGE] followed by densitometry analysis of RBC membrane proteins) before and immediately after the HD procedure in 20 patients (10 responders and 10 non-responders to recombinant human erythropoietin therapy [rhEPO]) and 26 healthy controls. Before HD, patients presented anaemia and significant changes in membrane protein composition, namely, a statistically significant reduction in spectrin associated with a significant increase in bands 6, as well as an altered membrane protein interaction (protein 4.1/spectrin, protein 4.1/band 3, protein 4.2/band 3 and spectrin/band 3). After HD, we found that patients showed a statistically significant increase in RBC count and hemoglobin, a further and statistically significant decrease in spectrin, an increase in band 3, and an altered spectrin/band 3 ratio. When comparing responders and non-responders patients after HD, we found that the non-responders presented a trend to a higher reduction in spectrin. Our data suggest that HD procedure seems to contribute to a reduction in spectrin, which is normally associated with a reduction in RBC deformability, being that reduction in spectrin is higher in non-responder patients.

DMT1 (NRAMP2/DCT1) Genetic Variability and Resistance to Recombinant Human Erythropoietin Therapy in Chronic Kidney Disease Patients under Haemodialysis

a Faculdade de Farmacia, Servico de Bioquimica, b Instituto de Biologia Molecular e Celular, and c Instituto de Ciencias Biomedicas Abel Salazar, Universidade do Porto, Porto , d Instituto de Ciencias da Saude, Universidade Catolica Portuguesa, Porto , e Centro de Investigacao de Ciencias da Saude da Universidade da Beira Interior, Covilha , f Instituto de Farmacologia e Terapeutica Experimental, Universidade de Coimbra, Coimbra , g FMC, Dinefro – Dialises e Nefrologia, SA, Maia , h Uninefro – Sociedade Prestadora de Cuidados Medicos e de Dialise, SA, Guimaraes , Portugal

Letter to the Editor: A potential mechanism for the pathogenesis of psoriasis vulgaris

depigmentosus presents with hypopigmented macules or patches that may be arranged along Blaschko’s lines; however, atrophy, which is a characteristic clinical feature of LAM, is not observed within the lesions. In lichen sclerosus, porcelain-white, albeit sclerotic, lesions are noted. Histopathologic findings of interphase dermatitis and papillary sclerosus, not present in our patient, are indicative of this disorder. The concept of twin spotting provides a plausible explanation for a number of paired skin disorders. New associations, if reported, will expand the clinical spectrum of this phenomenon in the years to come.