Glossary

an acquired disease (like PNH) is not contagious or inherited from a family member.

It is a disease that develops over the course of someone’s life.

a condition where the body does not have enough red blood cells and therefore has a lower ability to carry oxygen to vital organs. This may lead to fatigue and other symptoms such as breathlessness, palpitations, light headedness and a pale complexion.

an immune disorder where the bone marrow does not produce enough healthy blood cells including red blood cells, white blood cells and platelets. It is not uncommon for PNH patients to also have aplastic anaemia as well.

These are also referred to as blood thinners and are drugs that decrease the clotting ability of the blood and help prevent the formation of blood clots.

Blood clots can block blood flow in the veins and arteries depending on their size and location.

This is the soft tissue inside your large bones. Bone marrow contains stem cells which form red blood cells, white blood cells and platelets in a process called haematopoiesis.

This is part of the immune system that destroys bacteria and other foreign cells. In PNH, the complement is responsible for the destruction of red blood cells that lack the protective GPI anchor proteins.

This is difficulty swallowing caused by abnormal contractions/spasms of muscles in the oesophagus.

This is difficulty in breathing resulting in shortness of breath.

This drug is a humanised monoclonal antibody which is also known by its trade name as Soliris.

A lab test that shows the amounts of different blood cells (red, white and platelets) in the blood.

These are iron preparations often prescribed for PNH patients with anaemia. They are often given as tablets and liquid formulations and rarely as intravenous infusions.

This is a vitamin which the bone marrow needs to help it produce blood cells. It can be taken in tablet form.

This is an anticoagulant sometimes prescribed to pregnant women with PNH to reduce the risk of developing blood clots.

This is the brownish-red substance (pigment) in red blood cells that carries oxygen throughout the body.

This is the destruction of red blood cells. If this happens over a long period of time it is called chronic haemolysis.

Red, dark or black urine caused by the presence of free haemoglobin in the urine. The free haemoglobin is a result of the destruction of red blood cells by the complement part of the immune system which causes the red blood cells to burst. When the red cells burst, this releases haemoglobin into the blood plasma which overflows through the kidneys into the urine. This is different from “haematuria” which is bleeding into the urine.

This is an enzyme which is found in the blood and other body tissues. One of the things that can cause LDH levels to be raised is the destruction of red blood cells. Therefore LDH levels are an extremely useful marker of haemolysis. LDH levels usually reduce significantly after a patient has started treatment with eculizumab.

This is an infection caused by the bacterium Neisseria meningitidis (also called meningococcus). This bacterium can cause meningitis or widespread blood infection (sepsis). A fully functioning terminal complement system (part of the immune system) is necessary to prevent this infection.

This is a condition in which the bone marrow makes blood cells which are abnormal (misshaped, dysplastic).

These are the blood cells that are involved in blood clotting. Low platelet counts are associated with increased bleeding and bruising. Activated or stimulated platelets can clump together in the wrong place leading to the formation of blood clots or thrombosis.

The group of cells in the body that are affected by the genetic defect that causes PNH. These cells all come from the same parent cell in the bone marrow. Since the genetic defect lies in the parent cell, all cells which come from the parent cell, (including red blood cells, white blood cells and platelets) are affected. The size of a PNH clone depends on the number of cells affected by PNH. A PNH clone is tested on a regular basis in order to identify whether a PNH clone has increased, decreased or is stable.

The liquid part of the blood.

These are antibiotics which are taken when there is no infection present and in order to prevent one. If a patient is being treated with eculizumab, they are required to take these daily.

This is high blood pressure in the arteries that deliver blood to the lungs. Therefore the blood has a hard time getting to the lungs causing the heart to pump harder.

These cells carry oxygen around the body as they contain haemoglobin which binds to and transports oxygen.

The formation or development of a blood clot that often blocks blood from flowing through a vessel. In PNH, blood clots can occur in common places (leg veins and lungs) but can also occur in unusual places such as in vessels in the abdomen and brain.

This is an anticoagulant normally used in the prevention of blood clots. Due to the high risk of blood clots in PNH, preventative treatment with warfarin can potentially decrease the risk of blood clots.

These cells are responsible for fighting infections. A low white cell count can mean someone is more prone to infections.