A Medical Emergency

A case here that I wasn’t expecting to see on a recent weekend late shift, but a condition that is a medical emergency and fatal without the appropriate treatment, Thrombotic Thrombocytopenic Pupura or TTP for short.

This is a rare condition, and therefore even more important to keep in the forefront of the scientist’s mind when reviewing blood results. 

This patient attended Accident and Emergency, very unwell with a rash. The platelet count was 4 x10^9/l. The blood film was classic, severe thrombocytopenia with numerous fragments of red cells. This picture is consistent with  microangiopathic haemolysis.

Other significant markers are a raised bilirubin, LDH, Reticulocyte count , all markers of haemolysis and a raised creatinine, indicative of renal damage.

 

In this condition, clots are forming in blood vessels throughout the body, blocking oxygen flow to the body’s organs including  the brain, kidneys and heart, leading to complications such as stroke, myocardial infarction and renal failure.

The platelet count was so low because the platelets are being used up as the clots are forming, which will result in bleeding internally and under the skin. The red cell fragments are caused by red cells squeezing past blood clots, which leads to anaemia and a progressively falling haemoglobin. 

 For Scientists the action should involve

1. looking under the microcscope immediately on any new low platelet count. 

2. Note whether the haemoglobin is dropping aswell. 

3. The presence of red cell fragments, polychromasia and thrombocytopenia on a blood film is highly suggestive of a microangiopathic haemolytic anaemia which includes TTP and HUS. DIC also gives a similar picture. 

NOTE: even the very occasional red cell fragment is enough to consider this condition.

4. Add haemolysis markers on. We added a reticulocyte count, bilirubin and LDH. 

5.Phone the Consultant Haematologist and clinician immediately with all the relevant             information.

6. Further tedts of use are ADAMST13, Haptoglobin, clotting screen and D-Dimer.

The condition is caused by a lack of an enzyme called ADAMST13 that breaks down a clotting protein, Von Willebrand factor. This patient was indeed very deficient in ADAMST13. The cause of this to happen in this patient is unknown, but something had triggered the body to make antibodies against ADAMST13. A virus perhaps. In a separate case I was involved in a few years ago, a drinking binge in a young adult, triggered TTP!

The treatment for TTP is to exchange the plasma, giving back the ADAMST13 enzyme, which is a life saving treatment. Very sadly this patient didn't survive long enough to receive this treatment.

 This is a medical emergency with often only hours before life threatening and fatal complications occur, which unfortunately was the outcome in this case.