A clotting factor replacement for factor XIII deficiency
Factor XIII
A clotting factor given by injection into a vein to treat and prevent bleeding in factor XIII deficiency.
What is Factor XIII?
Factor XIII is a specialist medicine that replaces a clotting protein people with the rare inherited factor XIII deficiency are missing, so their blood can form stable, lasting clots. It is given by injection into a vein, usually on a regular schedule to prevent bleeds, as well as to treat bleeds. Some people can develop antibodies (inhibitors) that stop it working, and there is a small risk of clots. Some products are made from donated human plasma, which carries a very small risk linked to blood products, while recombinant (laboratory-made) products avoid that risk. It is used under the care of a specialist team.
Education and reference only. This is a plain-language guide to Factor XIII — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Factor XIII is a clotting protein that works at the final step of clotting, strengthening and stabilising a clot so it holds firm. People with the rare inherited factor XIII deficiency are missing or low in this protein, so clots that form are weak and can break down, leading to bleeding that may be delayed. Factor XIII medicine replaces the missing protein, allowing stable clots to form. It is given as an injection into a vein, often as a regular preventive treatment because the deficiency carries a risk of serious bleeds. Some products are recombinant (laboratory-made) and some are plasma-derived, and it is used under specialist care.
How it works
Most clotting factors help build a clot, but factor XIII acts at the very end, cross-linking the clot's framework so it becomes strong and stable rather than fragile. In factor XIII deficiency, clots do form at first but are weak, so they can break down and bleeding restarts, sometimes after a delay. The medicine supplies factor XIII so that clots are properly stabilised and hold. Because the protein lasts a relatively long time in the blood, it is often given on a regular preventive schedule spaced out over time, which helps protect against the serious bleeds that this deficiency can cause.
Company & origin
Originated / developed by: Specialist manufacturers.
A specialist medicine used in the UK to treat and prevent bleeding in the rare inherited factor XIII deficiency, replacing the missing clotting protein by injection into a vein.
Practical use
How to take Factor XIII
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection into a vein, often on a regular preventive schedule as well as to treat bleeds, as your specialist team advises.
- Because doses can be spaced out, it is important to keep to the schedule your team sets.
- Treat or report a bleed promptly, as bleeding in this condition can sometimes be delayed.
- Tell your team if it seems to be working less well, as this can be a sign of inhibitors developing.
- Keep in close contact with your specialist team and carry information about your condition.
Weighing it up
Advantages & disadvantages of Factor XIII
Advantages
- Replaces the missing protein so clots become stable, treating and preventing bleeds in factor XIII deficiency.
- Can be given on a spaced-out preventive schedule, helping protect against serious bleeds.
- Recombinant (laboratory-made) products avoid the small risk linked to human plasma products.
Disadvantages
- Some people can develop antibodies (inhibitors) that stop the factor working.
- There is a small risk of unwanted clots in some situations.
- Plasma-derived products carry a very small theoretical risk linked to blood products.
Practical use
Good to know
The key idea is that factor XIII works at the final step of clotting, locking a clot in place so it stays strong; replacing it lets people with the deficiency form stable clots rather than ones that break down. Because the deficiency can cause serious bleeds, including dangerous bleeding into the brain, it is often given as regular preventive treatment rather than only when a bleed happens, and the protein lasts long enough that doses can be spaced out. As with other clotting factor treatments, some people can develop antibodies, called inhibitors, that stop it working, and there is a small risk of unwanted clots, so the team monitors for both. Where the product comes from matters too: plasma-derived products are made from donated human blood and carry a very small theoretical risk linked to blood products, while recombinant products are laboratory-made and avoid that risk. Treatment is overseen by a specialist team, who plan the schedule and check that it is working.
Who should not take it / use with caution
- People who have had a serious allergic reaction to a factor XIII product should not use that product.
- It is used with extra care in people who have developed inhibitors or who are at higher risk of clots, under specialist guidance.
- It should only be used under the care of a specialist team.
Monitoring
- Checking factor XIII levels and that the preventive schedule is keeping bleeds under control.
- Checking for inhibitors (antibodies) that can stop the factor working.
- Watching for allergic reactions and, where relevant, signs of clots.
Side effects
- Allergic-type reactions, which can range from mild to, rarely, serious.
- Development of inhibitors (antibodies) that make the treatment work less well.
- Reactions where the injection is given, and, uncommonly, unwanted clots.
Key interactions
- There are few routine medicine interactions, but tell your team about all your medicines.
- Medicines that affect clotting are reviewed by the team, as they may change bleeding or clotting risk.
- Switching between products is done under specialist guidance, with monitoring for inhibitors.
Available as: A powder made up into a solution for injection into a vein.
Answers
Factor XIII: frequently asked questions
What is factor XIII used for?
It treats and prevents bleeding in the rare inherited factor XIII deficiency by replacing factor XIII, the clotting protein that stabilises clots, which people with the condition are missing.
How is factor XIII different from other clotting factors?
It works at the final step of clotting, cross-linking and strengthening a clot so it holds firm, rather than helping to build the clot in the first place.
Why is it often given regularly?
The deficiency can cause serious bleeds, so it is often given as regular preventive treatment; the protein lasts long enough that doses can be spaced out.
What is the difference between plasma-derived and recombinant factor XIII?
Plasma-derived products are made from donated human blood and carry a very small theoretical risk linked to blood products, while recombinant products are laboratory-made and avoid that risk.
Can inhibitors develop?
Yes, some people can make antibodies (inhibitors) against the factor that stop it working; the team checks for these if treatment seems less effective.
Authoritative sources
- BNF
- NICE CKS
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