Hemolysis in Patients With Hereditary Spherocytosis (HS)

• ROS, reduced glutathione (GSH) and lipid peroxides will be measured in RBC [ Time Frame: year ] [ Designated as safety issue: Yes ]
  ROS, reduced glutathione (GSH) and lipid peroxides will be measured in RBC following incubation with with 100 μM 2'-7'-dichlorofluorescin diacetate, 40 μM [1-(4-chloromercuryphenyl-azo-2-naphthol)] and fluor-DHPE, respectively for ROS [8] and with mercury orange for GSH [9]. After being washed twice, the cells will be resuspended in PBS and analyzed by flow cytometry .
  
  

• Hemolysis [ Time Frame: year ] [ Designated as safety issue: Yes ]
  Hemolysis will be assayed by suspending 3 ml of packed RBC in PBS or in the autologous plasma and overnight incubation in the presence of various concentrations of antioxidants such as fermented papaya preparation (FPP)
  
  

The oxidative status of cells, which is determined by the balance between pro-oxidants, such as the reactive oxygen species (ROS), and antioxidants, is a major regulator of cellular functions. Impaired balance between pro- and antioxidants causes oxidative stress which may result in oxidation of proteins, lipids and DNA with the final outcome of premature cell aging and apoptosis [1,2]. Oxidatively stressed red blood cell (RBC) have been observed in various congenital and acquired hemolytic anemias, including thalassemia, sickle cell anemia, congenital dyserythropoietic anemia, G6PD deficiency and paroxysmal nocturnal hemoglobinuria (PNH) as well as in myelodysplastic syndrome (MDS). Although the primary etiology is different in these anemias, oxidative stress mediates several of their pathologies, mainly hemolysis [3].

Hereditary Spherocytosis (HS) is a genetic disorder of the RBC skeleton with primary deficiency in spectrin, ankyrin-1, band 3 or protein 4.2 associated with chronic hemolytic anemia [4]. Secondary protein deficiencies resulting from oxidative stress are often observed and may be involved in the clinical manifestations of the disease [5].