How can immunotherapy help my subglottic stenosis?

Immunotherapy is becoming a more frequently used approach for patients who are having frequent dilations – by frequent we mean every six months or more often. There are a number of options available, and commonly used for other health conditions, so the side effects are well known and they are not considered experimental.

Rituximab is the most frequently used (also known by its brand names of MabThera, Rixathon and Truxima), but if this does not work successfully for you, there are other options available such as CellCept (mycophenolate mofetil) which also works to help your body stop attacking what it perceives to be a foreign body (such as your airway) by inhibiting B-cell and T-cell function. This chapter concentrates on Rituximab as the most used immunotherapy drug for airway stenosis.

What is Rituximab?

Rituximab is a drug most used to treat severe rheumatoid arthritis, as well as diagnosed autoimmune diseases such as granulomatosis with polyangiitis (Wegener's), also known as GPA.

But I haven’t been diagnosed with GPA, rheumatoid arthritis or a known autoimmune disease – why would I have this treatment?

There is a well-documented train of thought that suggests ‘idiopathic’ subglottic stenosis is a localised form of GPA and therefore treating it with the same medication will have good results despite biopsies and blood tests not proving GPA is present (you might hear you are ANCA negative). Even if you are ANCA positive, biopsies may not detect any signs of GPA.

What does Rituximab do?

Rituximab targets white blood cells in your body called B-cells (B-lymphocytes). These cells are part of the body’s immune system, responsible for attacking what they perceive as foreign bodies, and for creating an inflammatory response. Inflammation is frequently noted by doctors treating subglottic stenosis.

Is this a cure for subglottic stenosis?

For many patients, infusions of Rituximab put subglottic stenosis into remission, meaning it stops the airway closing up. Most patients get a longer period surgery-free, with studies frequently stating an average of 31-32 months (more than 2.5 years) between dilations. Your doctor will monitor your reaction closely and advise if another course of Rituximab is recommended.

How do patients receive this medication?

It is administered via an intravenous infusion – straight into a vein in the back of your hand or in the crook of your arm.

The infusion takes around 6-8 hours as it is given to you slowly, allowing medical professionals to monitor your reaction to the drug and act quickly to slow or stop administration if you have any adverse reactions. Before the Rituximab is administered, antihistamine and steroids will be infused. This is to help minimise any adverse reactions to the drug.

So, is Rituximab chemotherapy?

No, it is not chemotherapy. It is a targeted antibody therapy – immunotherapy. It can be used alongside chemotherapy with cancer patients, but is not chemotherapy itself.

How often do you have to do it?

The initial treatment usually consists of two to three sessions (about 6 to 8 hours each) two weeks apart. This will then subdue your B-cells for approximately six months. Depending on how well your stenosis responds (i.e. whether you need another dilation) you may need another round of two sessions 6-10 months after your first. Your blood will be monitored regularly. Patients who are positive for GPA (with symptoms impacting other areas of their body in addition to their airway) may need four sessions.

How long does it take to make a difference?

It takes about six weeks to take its full effect.

Do you need to take any other medication?

Some doctors prescribe prednisone to be taken orally for several months, while others may prescribe a low dose antibiotic to help prevent any bacterial infections, taken long term.

If I have a limited immune system, am I at risk from other illnesses?

If you catch a virus, such as Covid-19, a cold or flu for example, you are likely to get sicker for longer, and more severely than you would if you did not have this treatment. It is advisable you are vaccinated against Covid-19 (and potentially pneumonia, shingles and flu) before starting infusions – talk to your specialist about their recommendations. Blood tests will check you have not had hepatitis-B and assess the current health of your blood, lungs and kidneys. People with existing serious infections should not receive Rituximab.

How should I prepare for an infusion?

Remain hydrated - particularly the day and evening before your infusion, which will help in finding a vein on the day.
Avoid caffeine on the morning of your infusion - it can raise your blood pressure and constrict your veins
Wear comfortable clothes and shoes – you will be attached to an IV pole so it will be challenging to remove clothing if you are too hot, and using the bathroom will require the use of only one hand. No complicated trousers or underwear! There are usually blankets if you get cold, but if you have long sleeves you won’t be able to remove a top to cool down. Ideally wear or bring footwear that is easy to slip on and off.
Move every hour – you are sitting for a long while. If you are keeping hydrated, you should be needing those bathroom breaks, and take advantage of it to avoid pressure sores and risk of clots.
Bring easy to eat snacks – again, you are one handed, so any food or drink you bring with you should be accessible
Bring phone with music and headphones – the drugs (particularly the antihistamine) may make you feel drowsy, so you are unlikely to want to read. Napping and listening to music is good.
Don’t forget your charger – you’re there for a few hours, so make sure your devices stay working

How will I feel during the infusion?

You are likely to feel drowsy. You will be sitting in a chair with your blood pressure being regularly monitored on one arm, with the infusion entering a vein on the other. If you have any reaction at all, no matter how minor you think it is, let the attending nurse know. This may include feeling itchy, numb lips, tingling tongue.

There will be a lot of beeping throughout the infusion. Normally this is to remind the nurse to come and check your blood pressure, and speed up (or slow down) the infusion. It will also beep if the line is bent or obstructed.

How will I feel afterwards?

Prevention is better than cure, and ensuring you are well hydrated should help you avoid the headache which plagues some people. Fatigue is the most common side effect, with some people feeling as though they have flu-like symptoms for up to four days.

You are given steroids intravenously which can cause insomnia for a night or two, so despite feeling tired, you may not be able to sleep. You may feel a temporary hunger (from the steroids), and other short term side effects are a burning sensation to face and skin and a dry, scratchy throat.

Can I still have other treatment on my stenosis as well as this?

Yes, all usual options (eg steroid injections/dilation) remain open to you while on this treatment plan.