Haemophilia and acquired bleeding disorders 

Haemophilia is an inherited condition that affects the blood's ability to clot.

Normally, when you cut yourself, substances in the blood known as clotting factors combine with blood cells called platelets to make the blood sticky. This makes the bleeding stop eventually.

However, in haemophilia, there aren't as many clotting factors as there should be in the blood. This means that someone with the condition bleeds for longer than usual.

UCLH is a designated Haemophilia Centre, and provides a 24/7 service for patients, including those needing treatment with blood products and clotting factor medications.

Through specialist haemostasis outpatient clinics and inpatient referrals, UCLH provides expert care for patients with a diverse range of bleeding disorders including:

  • haemophilia;
  • von Willebrand Disease and platelet function defects;
  • other acquired bleeding disorders.

Patients with bleeding disorders may require treatment during acute bleeding episodes, but also treatment when undergoing surgery or during childbirth. We therefore provide support to patients across UCLH hospital sites and across many specialties, to ensure patients receive necessary treatment.


Dr Marie Scully, Consultant Haematologist

Dr Marie Scully

Dr Scully was appointed as a consultant at UCLH in 2007, with an interest in haemostasis and thrombosis. She is clinical lead for haematopathology and blood transfusion at UCLH. She is also the lead for TTP and associated TMAs, including aHUS. UCLH is a specialist centre for TTP.

Full consultant profile

Dr Mari Thomas, Consultant Haematologist

Dr Mari Thomas is a new Haematology consultant joining the Thrombosis team at UCLH. She recently completed a PhD at UCL looking into the role of antibodies in TTP. As part of the TTP team, she manages both inpatients and outpatients with TTP and other thrombotic microangiopathies, such as atypical HUS. Her other areas of interest include venous thromboembolism in cancer patients.

Dr Thomas is starting a new clinic for cancer VTE in the UCLH MacMillan Cancer Centre. She also specialises in obstetric haematology, running a joint antenatal clinic for high-risk pregnancies with Dr Cohen and obstetric colleagues. She acts as liaison between the transfusion laboratory and the Fetal Medicine Unit for women with red cell alloantibodies in pregnancy.

"The most rewarding part of my work is working with a great team and seeing our research findings translated into better outcomes for patients."

Full consultant profile

Dr John-Paul Westwood, Consultant Haematologist

Dr John-Paul Westwood specialises in Haemostasis and Thrombosis, including Thrombotic Thrombocytopenic Purpura (TTP), Immune Thrombocytopenia (ITP), and bleeding disorders. He also work as a Transfusion consultant. His research intrests are in non-malignant haematology, including TTP and ITP. I am also involved in supporting clinical trials in these disease areas.

“The most rewarding part of my work at UCLH is treating patients with varied and often challenging diseases in the field of haemostasis and thrombosis”

Full consultant profile

 Clinical Nurse Specialists (CNS)

Siobhan McGuckin, TTP Clinical Nurse Specialist

Siobhan McGuckin

Siobhan McGuckin specialises in thrombotic thrombocytopenic purpura (TTP), haemophilia / bleeding service and immune thrombocytopenic purpura. Her research focuses on complications of plasma exchange for TTP and thrombotic microangiopathy (TMA).

“The most rewarding part of my role at UCLH is dealing directly with my patient groups, but especially the acutely ill TTP and TMA patients”