Post-natal decline of fetal haemoglobin in homozygous sickle cell disease: relationship to parental Hb F levels

SummaryIt has recently been proved that, in vitro, red blood cells (RBCs) from patients with homozygous β-thalassemia behave as procoagulant cells. The procoagulant activity of β-thalassemia RBCs might be the result of an increased exposure of procoagulant phospholipids (i. e. phosphatidylserine) in the outer leaflet of the membrane. In order to test this hypothesis, we compared the catalytic properties of RBCs of patients with β-thalassemia and homozygous sickle cell disease (SS-RBCs) with that of controls. The catalytic parameters (Km, kcat) of prothrombin activation by factor Xa were determined both in the absence and in the presence of RBCs. The turn-over number (kcat) of the reaction was not modified by normal, SS- or (3-thalassemia RBCs. The Km was lower in the presence of normal RBCs (mean value: 9.1 µM) than in the absence of cells (26 µM). The Km measured in the presence of either SS-RBCs (mean value: 1.6 µM) or β-thalassemia RBCs (mean value: 1.5 pM) was significantly lower compared to normal RBCs (p <0.001). No significant difference was observed between SS-RBCs and p-thalassemia RBCs. Annexin V, a protein with high affinity and specificity for anionic phospholipids, inhibited the procoagulant activity of both SS-RBCs and (3-thalassemia RBCs, in a dose-dependent manner. More than 95% inhibition was achieved at nanomolar concentrations of annexin V. These results indicate that the procoagulant activity of both β-thalassemia RBCs and SS-RBCs may be fully ascribed to an abnormal exposure of phosphatidylserine at the outer surface of the red cells.

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Clinical findings associated with homozygous sickle cell disease in the Barbadian population – do we need a national SCD registry?

BMC Research Notes ◽

10.1186/1756-0500-7-102 ◽

2014 ◽

Vol 7 (1) ◽

Cited By ~ 7

Author(s):

Kim R Quimby ◽

Stephen Moe ◽

Ian Sealy ◽

Christopher Nicholls ◽

Ian R Hambleton ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Clinical Findings ◽

Cell Disease ◽

Homozygous Sickle Cell Disease

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Screening for Sickle Cell Disease: A Hospital Based Study in Eastern Odisha, India

South Asian Journal of Experimental Biology ◽

10.38150/sajeb.2(2).p57-60 ◽

2012 ◽

Vol 2 (2) ◽

pp. 57-60

Author(s):

Jayanti Mishra ◽

Sanghamitra Pati ◽

Mohammad Akhtar Hussain ◽

Niraj Srivastava ◽

Sindhubala Mishra

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Trait ◽

Cell Disease ◽

Medicine Department ◽

Fetal Haemoglobin ◽

Medical College ◽

Rbc Indices ◽

And Gender ◽

Cell Gene

The highest frequency of sickle cell gene in India is reported in Odisha. The present study was taken up to assess the presence of sickle cell disease among febrile patients of a medical college of eastern Odisha. Patients referred from both pediatric and medicine department to the Hematology section of the department of Pathology, SCB Medical College, Cuttack were subjected to measurement of RBC indices, Sickling test, Haemoglobin Electrophoresis and Fetal Haemoglobin Estimation. Out of total 1000 referred patients 76(7.6%) were found to be positive for sickling. Twoâ€third of sicklingpositive patients had sickle cell trait with electrophoretic AS band. There was a significant association between age and positive sickling (χ2 = 24.357; df = 4, P = <0.0001). No significant association was observed between sickling and gender. Sickle cell positive cases are not uncommon in eastern Odisha. Our study demonstrated sickle cell trait to be more common among screened patients than other forms of sickle cell diseases.

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