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Hepatitis B reactivation with rituximab: what you need to know | CION Cancer Clinics
Yes, rituximab can reactivate hepatitis B, even an old infection you never knew about. It lowers the part of the immune system that keeps the hidden virus quiet. So everyone is tested before the first dose, and people with a past or current infection are protected with an antiviral medicine or regular blood checks. For most, lymphoma treatment goes ahead as planned. Yellow eyes or dark urine need a same-day call. At CION Cancer Clinics, our haematology team plans myeloma and lymphoma care with you, discussed at a tumour board and explained in plain words.
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Medically reviewed by Dr. Basudev PokhrelConsultant Haematologist · last reviewed September 2026, next review due September 2027
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On this page
- Why can rituximab wake up hepatitis B?
- What happens before rituximab is started?
- What do the hepatitis B report words mean?
- What does your result usually mean for the plan?
- What do families get wrong about hepatitis B and rituximab?
- What should the family do, and what can this page not tell you?
- Common questions about hepatitis B and rituximab
The short answer
Why can rituximab wake up hepatitis B?
Rituximab can let a hepatitis B infection that was quiet, or that you never knew you had, become active again. That is why every person is tested for hepatitis B before the first dose, and why some people take an antiviral medicine alongside treatment.
How a quiet infection comes back
After a hepatitis B infection, even one that cleared years ago, the virus can stay hidden inside liver cells. Your immune system keeps it in check. Rituximab removes B cells, the white cells that make antibodies, and that part of the guard drops. The hidden virus can then start copying itself again. Doctors call this reactivation.
Why it matters
Reactivation can inflame the liver. In some people it stays mild and is only seen in blood tests. In others it causes jaundice, the yellowing of the eyes and skin, and it can occasionally lead to serious liver failure. It can also force a pause in lymphoma treatment, which is the thing everyone wants to avoid.
Why this is common in India
Many adults in India were exposed to hepatitis B in childhood without ever feeling ill. A lot of them have no idea. That is why testing is done for everyone, not only for people who think they are at risk.
A past infection is not something to feel ashamed of. It is simply information the team needs before planning treatment.Before the first dose
What happens before rituximab is started?
A hepatitis B blood test
A blood sample is checked for signs of a current or past hepatitis B infection. It is part of routine work-up and is done even if you were tested some time ago or were vaccinated.
More tests if anything is positive
If a marker shows up, the team usually measures how much virus is in the blood and checks your liver tests. Sometimes a liver specialist is asked to see you too.
A plan to protect the liver
Depending on the result, you may be started on an antiviral medicine before rituximab, or have your blood checked regularly instead. The choice depends on your own results and history.
Treatment goes ahead
For most people with a positive test, lymphoma treatment still goes ahead as planned. The test changes how you are protected, not whether you are treated.
Not sure whether this applies to you?
Ask an oncologistOn your report
What do the hepatitis B report words mean?
- HBsAg
- The surface marker of the virus. Positive usually means the infection is present in the body now.
- Anti-HBc (core antibody)
- Shows you have met the virus at some point. Positive with a negative HBsAg usually means a past infection that is being held in check.
- Anti-HBs (surface antibody)
- Protective antibody, from vaccination or from recovering from the infection. On its own it does not remove the need for the other tests.
- HBV DNA or viral load
- How much virus is in the blood. It is used to decide on treatment and to watch for reactivation.
- ALT and bilirubin
- Liver blood tests. A rise can be an early sign of liver inflammation, though many other things raise them too.
Laboratories use different reference ranges. A single result is always read alongside your other tests and history.
Where you might fit
What does your result usually mean for the plan?
These are the broad groups. Your haematologist fits your actual numbers into them, and some people fall between groups.
No sign of hepatitis B
Both HBsAg and core antibody are negative. Reactivation is not a concern. Your team may suggest vaccination, though the response can be weaker once treatment has begun.
Past infection
HBsAg is negative but core antibody is positive. Rituximab can still reactivate the virus. Many teams give an antiviral medicine as prevention; others check viral load at regular visits.
Usually involves
- Regular liver and viral load tests
- An antiviral, if the team advises it
Current infection
HBsAg is positive. The risk of reactivation is higher, so an antiviral medicine is generally started before rituximab and continued well after the last dose. A liver specialist often shares your care.
!
Signs that need a doctor the same day
Yellow eyes or skin, very dark urine, pale stools, vomiting, pain under the right ribs or unusual tiredness during or after rituximab need a call to your team the same day. If there is confusion, heavy drowsiness or bleeding, call 108 or go to the nearest emergency department now and say the person is on rituximab.
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Commonly believed
What do families get wrong about hepatitis B and rituximab?
"I was vaccinated, so I do not need the test."
Vaccination protects against new infection. It does not tell anyone whether you were infected before the vaccine. The test is still needed, and the team reads your antibody results together.
"The old infection cleared years ago, so it cannot come back."
A cleared infection can leave virus hidden in the liver. This is exactly the group that rituximab can catch out, which is why a positive core antibody changes the plan even when you feel well.
"Once the lymphoma treatment ends, the antiviral can stop."
Reactivation can happen months after the last dose, because B cells take a long time to come back. The antiviral is usually continued well beyond the end of treatment. Never stop it on your own; your team decides when.
"A positive test means lymphoma treatment will be refused."
Almost always, treatment still goes ahead. The result adds protection to the plan. Delaying treatment out of fear of the test usually does far more harm.
Being straight with you
What should the family do, and what can this page not tell you?
If your test shows a current hepatitis B infection, the people you live with should be tested too. Anyone found not to be infected and not protected can be vaccinated. This is ordinary care for the household, and it does not need to wait for anything.
Keeping the antiviral going
If you are given an antiviral, take it exactly as prescribed and do not let the supply run out between visits. Tell every doctor you see, including a dentist or a doctor treating something else, that you take it. Bring the strip to each appointment.
What this page cannot tell you
It cannot read your own report, tell you which group you are in, or say how long your antiviral will continue. It cannot tell you whether a rise in a liver test is the virus, another medicine or something else. Those answers come from your haematologist, who sees your results over time.
Keep a copy of every hepatitis B report in the folder you bring to treatment. Teams at other hospitals will ask for it.Questions we are asked
Common questions about hepatitis B and rituximab
Is hepatitis B reactivation common with rituximab?
It depends on your hepatitis B status. People with no sign of the virus are not at risk. People with a past or current infection carry a real risk, higher for current infection. Testing and an antiviral where needed lower that risk a great deal, which is why the test comes first.
My test came back positive. Should I panic?
No. A positive result is common and it is manageable. It tells the team to protect your liver while treating the lymphoma. Ask which marker was positive, whether you will take an antiviral, and how often your liver will be checked. Write the answers down for the family.
Does the antiviral medicine have side effects?
The antivirals commonly used are generally well tolerated. Some people notice mild tiredness, headache or stomach upset. Your kidney function may be checked from time to time with some of them. Tell your team about anything new rather than stopping the tablet yourself.
Can reactivation happen after treatment is finished?
Yes. Because B cells recover slowly, the risk continues for a long time after the last dose. That is why protection and blood checks carry on after treatment ends. Keep attending follow-up visits, even when you feel completely well.
Does this also apply to other lymphoma medicines?
Other medicines that remove B cells, and some chemotherapy and steroid combinations, carry a similar concern. Your team checks hepatitis B status before most lymphoma treatments for this reason. If your plan changes, ask whether your hepatitis B protection needs to change too.
Can I pass hepatitis B to my family?
A current infection can pass through blood, sexual contact, and from mother to baby. It does not spread through sharing food or hugging. Do not share razors or toothbrushes. Household members should be tested and vaccinated if they are not already protected.
Will I need a liver specialist?
Sometimes. People with a current infection, a high viral load or abnormal liver tests are often seen jointly by a liver specialist. Your haematology team coordinates this, so you are not running between two plans that do not talk to each other.
What if hepatitis B reactivates despite precautions?
It is uncommon with protection in place, but it can happen. Rituximab may be paused, the antiviral adjusted by your team, and the liver watched closely. Picked up early through blood tests, it is usually brought under control. This is why regular checks matter.
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Sources
- NHS — Hepatitis B
- World Health Organization — Hepatitis B fact sheet
- National Cancer Institute — Rituximab
- Cancer Research UK — Rituximab
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
Rituximab Infusion ReactionsWhat the first drip feels likeLow Immunoglobulins After RituximabThe other way rituximab affects immunityVaccination During and After Lymphoma TreatmentIncluding hepatitis B vaccine for the familyLymphoma Treatment Experience and Side EffectsEvery side-effect guide for lymphoma treatment
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