In the thick of it: cerebral venous sinus thrombosis precipitated by iron-deficiency anaemia and sickle cell trait

Iron restriction in sickle cell disease: When less is more

Primum non nocere! Can iron deficiency, an abnormality that causes anemia, benefit people with sickle cell disease (SCD) who already have an anemia? The published literature we review appears to answer this question in the affirmative: basic science considerations, animal model experiments, and noncontrolled clinical observations all suggest a therapeutic potential of iron restriction in SCD. This is because SCD's clinical manifestations are ultimately attributable to the polymerization of hemoglobin S (HbS), a process strongly influenced by intracellular HbS concentration. Even small decrements in HbS concentration greatly reduce polymerization, and iron deficiency lowers erythrocyte hemoglobin concentration. Thus, iron deficiency could improve SCD by changing its clinical features to those of a more benign anemia (i.e., a condition with fewer or no vaso-occlusive events). We propose that well-designed clinical studies be implemented to definitively determine whether iron restriction is a safe and effective option in SCD. These investigations are particularly timely now that pharmacologic agents are being developed, which may directly reduce red cell hemoglobin concentrations without the need for phlebotomies to deplete total body iron.

Bilateral Pulmonary Embolism after a Short-Haul Flight in a Man with Multiple Risk Factors including Sickle Cell Trait

We report a case of pulmonary embolism (PE) in an Afro-Caribbean man following a short commercial flight of less than 5,000 kilometers (Km) in economy class with a 1-month interval between journeys. He had an elevated body mass index (BMI) and sickle cell trait (SCT) with hyperhomocysteinemia. No other preexisting source of venous thrombosis was found. We posit that venous thromboembolism (VTE) and/or PE may have been a complication of SCT in an individual with other multiple risk factors. We discuss the possible interaction of these risk factors for VTE and/or PE and the implications for travelers at risk. The need for a PE risk score and guidelines for the prophylaxis of thromboembolism among travelers exists.