|by Sabrina Taner|
Wednesday 19 June 2013 marks the 5th annual World Sickle Cell Day, created to raise global awareness of sickle cell disease and its serious impact on health.
Our image of the month shows two red blood cells taken from a patient with sickle cell disease. After taking blood from the patient, the cells were collected onto a polycarbonate filter (the pores in the filter are visible in the background of the image) and then further processed so that they could be imaged by scanning electron microscopy. The two red blood cells, one normal and one diseased, were then digitally coloured to highlight the striking differences in their physical structure. The orange cell in the foreground of the image has been affected by sickle cell anaemia which gives the cell its abnormal characteristic ‘sickle’ or ‘crescent’ shape. This change in shape makes the cell less flexible which can cause it to block blood vessels in the body. Sickle cells often die prematurely which means that the body can’t make enough red blood cells to support its needs (anaemia).
Sickle cell anaemia is a genetic disease in which an individual inherits two copies of a faulty haemoglobin gene. Haemoglobin is an iron-rich protein in red blood cells responsible for binding to and carrying oxygen around the body. When oxygen is released into respiring tissues, haemoglobin picks up waste carbon dioxide and delivers it to the lungs to be expelled. People who only inherit one faulty copy of the haemoglobin gene do not develop sickle cell disease but instead become carriers. This is called ‘sickle cell trait’ and provides a protective advantage against malaria infection. The World Health Organization estimates that approximately 5 per cent of the global population carry mutated genes for haemoglobin disorders, specifically sickle cell disease and thalassaemia.
This scanning electron micrograph was acquired by Jackie Lewen whilst at the EM Unit at the UCL Medical School, Royal Free Campus. It was a Wellcome Image Award winner in 2009.