Malaria protection in hereditary ovalocytosis: relation to red cell deformability, red cell parameters and degree of ovalocytosis.

In the culture of red cells with Plasmodium falciparum, erythrocytes from both Thai patients and subjects (patient's parents) with hereditary ovalocytosis have a protective effect against malarial infection. High percentage of ovalocyte (75-100%) was found in patients whereas their parents had lower percentage (25-50%). Invasion index (II) and multiplication ratio (MR) of P. falciparum in these abnormal red cells from the patients were significantly decreased as compared to those in normal red cells (patients: II = 1.52 +/- 0.91, MR = 8.83 +/- 6.73; normal subjects: II = 4.45 +/- 1.51, MR = 25.23 +/- 6.25). This suggests that the red cells from these patients had significant degree of malaria protection. The significant protection was also shown in red cells from the parent group (II = 1.86 +/- 0.81, MR = 15.69 +/- 3.50). Although the parents had lower ovalocyte percentage, degree of protection against malaria parasite was as effective as those found in patients with high ovalocytic red cells. This has been confirmed by statistical analysis showing nonsignificant difference in II value between the two groups. In contrast, red cells of both groups had poor deformability (deformability index, DI) as compared to the normal group. No statistically different DI values were demonstrated between the two. This indicates that poorly deformable red cells, not their ovalocytic shape, make a significant contribution to limitation of malaria parasite invasion. The MR values in patients were less than those found in the parent group but statistical analysis showed no significant difference. Reduced MR values were found with increased numbers of microcytic, hyperchromic and hypochromic red cells in patients.

Measurements of cell volume and hemoglobin concentration of erythrocytes from hereditary ovalocytosis and hereditary spherocytosis.

Red cell analysis using the laser technique was done on erythrocytes from 11 cases of hereditary ovalocytosis (HV) and one case of hereditary spherocytosis (HS). Heterogeneity in red cell volume measured as red cell distribution width (RDW) and heterogeneity of hemoglobin concentration in the red cells as measured by hemoglobin concentration distribution width (HDW) were analyzed. All of the studied cases showed abnormal increase in both RDW and HDW. The patient with HS had decreased MCV 77.4 fL (normal range = 80-99 fL). The HS patient had microcytes 14.7 per cent with markedly increased RDW 22.3 per cent (normal range = 11.5-14.5%). Increased hemoglobin concentration was demonstrated in HS red cells as shown by increased CHCM 39.2 g/dl (normal range = 33-37) with 5.86 g/dl of HDW (normal range = 2.2-3.3 g/dl). The HV patients had slightly decreased cell volume, MCV = 84.1 +/- 11.8 fL, with 9.2 +/- 10.1 per cent microcytes and 17.5 +/- 5.7 per cent RDW. Decreased hemoglobin concentration was shown in HV red cells as shown by decreased CHCM (31.7 +/- 1.9 g/dl) with slightly increased HDW (3.3 +/- 0.9 g/dl). The HV patients had increased per cent hypochromic red cells (14.8 +/- 18.6%). The ovalocytic red cells in HV patients had obviously reduced hemoglobin concentration compared to the spherical red cells of HS patients.

Estudio clinico y bioquimico de 9 pacientes con eliptocitosis hereditaria / Clinical and biochemical study of 9 patients with hereditary elliptocytosis

Se estudiaron nueve pacientes (cuatro familias) con eliptocitosis herediataria (EH). Desde el punto de vista clínico, se identificaron dos tipos de presentación: siete pacientes fueron formas compensadas y dos (de 7 y 63 años) pertenecientes a distintas familias mostraron anemia, esplenomegalia, reticulocitosis y fragmentación globular. En una familia se comprobó una disminución del stock total de la proteína 4.1 en la electroforesis de proteína de membrana en gel de poliacrilamida con SDS (SDS-PAGE). Uno de sus miembros se comprobó como forma descompensada. El estudio de dímeros y tetrámeros y la digestión tríptica de espectrina fue normal en todos los casos. En la determinación de la deformabilidad en función de la osmoralidad con el ectacitómetro se halló una buena correlación entre el índice de deformabilidad (ID) y el grado de anemia. De acuerdo a los resultados de este estudio pudimos confirmar la gran heterogeneidad clínica de la EH aún en miembros de una misma familia

Estudio de la membrana del glóbulo rojo en 2 pacientes con eliptocitosis hereditaria / Study of red cell membrane in two patients with hereditary elliptocytosis

Se presentan los resultados de la prueba de fijación con glutaraldehído y electroforesis de las proteinas de la membrana del glóbulo rojo, realizadas a 2 familias con eliptocitosis hereditaria (EpH). Los hallazgos clínicos y bioquímicos mostraron 2 formas de presentación distintas de esta enfermedad. Un caso se clasificó como EpH esferocítica, ya que presentaba una prueba del glicerol y resistencia osmótica (RO) cuantitativa disminuida y en la fijación con glutaraldehído se observaron abundantes eliptocitos redondeados. En la otra familia, debido a la presencia de consanguinidad en los padres, no se pudo diferenciar entre la EpH común con hemólisis crónica y la EpH común hemolítica severa. La prueba de fiajción con glutaraldehído permitió realizar el diagnóstico diferencial entre esferocitosis hereditaria y EpH en una familia.

Abnormal haemoglobins and hereditary ovalocytosis in the Ulu Jempul District of Kuala Pilah, West Malaysia.

A survey of abnormal haemoglobins and hereditary ovalocytosis was carried out among 629 Malays of Minangkabau descent in the Ulu Jempul District of Kuala Pilah, in the state of Negri Sembilan in West Malaysia.. Several abnormal haemoglobins were found with the following frequencies: Hb E 5.25%, Hb CoSp 2.38%, Hb A2 indonesia 0.80%, a fast moving Hb with a Mobility between A and Bart's 0.64% and Hb Q 0.16%. Hereditary ovalocytosis was found in 13.2% of these people. None of the persons with hereditary ovalocytosis had any evidence of haemolysis.