Introduction

The SCAD project is building a special digital camera to try to photograph sickle cells in very small veins that lie just under the skin and inside the mouth. If the camera can spot these cells then we hope to turn it into a gadget for checking the severity of your sickle cell disorder.  The work is being done jointly by Imperial College and Nottingham University for the Sickle Cell Society; clinical testing is to be done at the Central Middlesex and Hammersmith Hospitals. The money comes from the Big Lottery.

The SCAD camera and your painful crises

Better treatments mean tackling the cause of the pain rather than the pain itself. In this article we try to explain the part that the SCAD camera might play. ‘Might’ is the important word here because we cannot guarantee success. Clues about better control of sickle cell disorder can be seen in how medical science now prevents heart attacks and strokes. Sickle cell crises, heart attacks and ischaemic strokes (pronounced iskeemick) have much in common. They are all blockages in the circulation of blood, are very painful and you never know when they are going to happen.

What medical science has discovered is:

1.  Heart attacks and ischaemic strokes are accidents waiting to happen because long-term changes have happened to blood and the blood vessels. One of these changes is the furring up of blood vessels with cholesterol.
2. Tests for these long-term changes have been found.
3.  Ways have been found to prevent or reduce these changes.

The point is that medical science tackles the cause of the pain & not the pain itself.

Tests: why they are vital

Because they:

•  Show if someone has the disease & the severity of the disease (how ill he/she is with it).
• Reveal if new drugs can attack the disease.
•  Allow doctors & nurses to decide on treatments.
• Allow doctors & nurses to tailor the treatment to the patient.

For example, the simplest test for furred-up blood vessels is what you often have when you visit the surgery. The doctor or nurse measures your blood pressure with a cuff around the upper arm. The heart has to work harder to pump blood around your body if your blood vessels are furred-up with cholesterol. The test is:

•  Quick.
•  Painless.
•  Non-invasive (nothing is stuck in you).

How hard your heart is working can be sensed all over the body but the arm is the most convenient place for the test. This is exactly the kind of test that we hope to develop with the SCAD camera although of course we won’t be measuring blood pressure. We have already been asked the question ‘why look at sickled blood in the finger or mouth when the sickle pain is elsewhere?’ Our answer is ‘because we believe that long-term changes will be found in sickled blood everywhere and so the most convenient and comfortable place to use the new camera does not have to be where your pain is.’

What next if we are successful?

If we can develop a test for disease severity then the next three steps in medical research will be (providing we raise the money):

1. Spot changes in the blood that are most likely to cause crises.

2. Find which patients have these kinds of changes.

3. Test existing treatments to see how good they are in treating patients most likely to have crises.

Who are we? 

Doctors, nurses and scientists from:

Central Middlesex Hospital; Hammersmith Hospital; Imperial College Medical School & University of Nottingham.

All are helping the Sickle Cell Society in this important work.

Dr Martin Pickstone,

Project Coordinator