From bruises to blood donation, menstruation to mozzies, the first season of It Can’t Hurt To Ask focuses on blood.
Your blood is a key player in your body’s immune response, carrying antibodies around your system to fight off infection and disease. In this episode, learn all about how antibodies work as part of the immune system from clinical immunologist Dr Peter Bourke. You’ll also hear from Cheryl, one of the many Queenslanders living with an autoimmune condition, about what it’s like when your immune system doesn’t behave the way it should.
How does your body learn about pathogens in order to fight them off? What are the steps in the immune response? What happens if your immune system gets it wrong and turns its efforts towards your healthy body? Listen to find out!
Featured in this episode
Dr Peter Bourke
Dr Peter Bourke is a clinical immunologist and allergist at Cairns Hospital. Immunologists are experts who study the immune system and treat conditions related to it, including autoimmune diseases like lupus or allergies.
Cheryl Dines
Cheryl Dines lives in Brisbane and was officially diagnosed with autoimmune disease rheumatoid arthritis in her mid-thirties after experiencing symptoms such as severe joint pain and swelling since she was in her teens. In this episode, she shares what it’s like to live with and manage her autoimmune disease and shares tips for people in a similar position.
Episode resources
Rheumatoid arthritis
This episode features the story of Queensland woman Cheryl, who lives with rheumatoid arthritis. In rheumatoid arthritis, the immune system attacks the lining of the joints causing inflammation, pain and swelling. You can read more about the condition from Arthritis Australia, and other types of autoimmune conditions on the Health Direct website.
Arthritis Assist Peer to Peer Mentoring Program
In this episode, Cheryl mentions the Arthritis Assist Peer to Peer Mentoring Program from Arthritis Queensland which she has previously participated in. You can find out more about the program on the Arthritis Queensland website.
Transcript
Vox pops: How does our body know when we have an infection?
What is an auto-immune disease?
How do vaccines work?
Can you really become immune to something?
Narrator: When you’ve got questions about your health, where do you go? From Queensland Health, It Can’t Hurt To Ask is the health podcast with the answers to your questions, concerns and curiosities.
'In My Blood’ is the theme of this season and today, we’re taking a closer look at antibodies.
Hi, I’m Lauren and this episode was recorded on the lands of the Jagera and Turrbal people. We acknowledge the Traditional Custodians and pay our respects to the Elders past and present.
Remember, whatever you hear in our episodes is general information. Always speak to your doctor about your individual circumstances.
Settled in? Let’s get to it.
Narrator: Our bodies are amazing systems, often doing incredible things we don’t even notice.
Today, we’re getting to know a tiny but powerful part of our blood and body: antibodies.
These are proteins in our blood that play a huge role in our immune system, which is our bodies defence system.
Antibodies spot and fight off invaders, like viruses or bacteria, helping to keep us safe from infections.
Anyone else getting visions of James Bond or a detective in a trench coat? No, just me... ?
To learn more about how our body creates antibodies, let’s hear from Dr. Peter Bourke, a clinical immunologist and allergist at Cairns Hospital.
Immunologists are experts who study the immune system and treat conditions related to it, including autoimmune diseases like lupus or allergies.
Dr Bourke: Antibodies are special proteins in the immune system that recognise structures on foreign pathogens, for instance. It's like a lock and a key or a piece of a jigsaw puzzle. They have a very specific fit to something on the shape of the antibody, of the pathogen.
They also have a part that activates the immune system. So once they recognise the pathogen, they activate the immune system to clear the pathogen.
Narrator: That sounds a bit technical, so let’s define some of those terms.
Pathogens are harmful things like tiny living organisms, bacteria or viruses that can make you sick. Think of them as unwanted guests in your body.
Antigens are parts of the pathogens. They act like a warning signal to your body, letting it know there's an infection or some other problem.
Dr Bourke: We actually generate a whole lot of random, slightly different antibodies as part of the adaptive immune system. And when your body sees a pathogen, you'll have at least a couple of antibodies that already recognise that pathogen just by chance.
And when your body sees that pathogen, the B cells that make those antibodies, they actually expand in number. So, you have what's really a memory response for the future because those antibodies that recognise that pathogen have now been expanded into a population, a larger population. So that if you get re-exposed to that pathogen, you've now got a whole lot of antibodies that you didn't have before against that pathogen.
Narrator: In our bodies, we have five types of antibodies, kind of like different fighters against diseases. They are igM, igG, igA, igE, and igD. Each one has its own special job.
IgM is like the leader of the pack. It's the first one we make when our body detects something new, like a germ. Once it finds this new germ, it can change into igG, igA, or igE.
Think of it as a cool trick our body does to protect us.
Dr Bourke: Once you stimulate IgM, there's what they call a switch and you start making IgG, which is the memory antibody. And depending on where you are in the body, you might switch to IgA, which is used for mucosal surfaces, like the lungs, the mouth, the genitorurinary tract. And then there's another antibody IgE, which is really, we think for parasites, like worms, fungus and so forth, it binds to those. And it's very sensitive. It's the one we make the least of but it has a very, it's got a hair trigger to it to generate a response and one of the pathological responses that IgE can do is allergy.
Narrator: Our own proteins and the pathogens can look very similar.
Sometimes our immune system can confuse the two and cause the body to attack our normal cells by mistake. This is what causes autoimmune disease.
We’ll talk more about this soon.
First, let’s watch, or hear, our antibodies in action.
Our immune system consists of two main parts: the innate immune system and the adaptive immune system.
The innate system is our first line of defence, responding immediately to all germs and foreign substances.
Imagine getting a cut on your skin; bacteria entering the wound could be neutralised within a few hours by this rapid-response team. However, its non-specific and speedy action means that its power is somewhat limited.
When the innate system can't quite handle the invading germs, that’s when the adaptive immune system steps in.
This part of our defence is more specific and precise, accurately identifying and targeting the intruder. It's like a specialised commando unit, tailored to fight specific enemies.
Although more accurate, it's slower to act compared to the innate system.
To understand how they both work together, let's imagine a scenario where a pathogen, perhaps a virus, invades our body. What happens first? How does our immune system react to this uninvited guest?
Dr Bourke: So, the virus comes into the body, say through the nose, so you might breathe it in through the mucosal, and it'll land on the mucosal surface. And it's then looking, it'll have a particular receptor that it's been adapted to bind to, and that would bind to that receptor on a cell, and then it will be taken into the cell.
So, if it actually happens quickly like that, and it gets into the cell, the antibodies won't be able to see it because antibodies can only see pathogens that are in either the blood stream or on mucosal surfaces, they can't see them once they're hiding inside a cell. The T cell is the cell that sees it when it's inside the cell. So, if it gets, if we haven't got antibodies to stop it getting into the cell, then the T cells are required to clear that infection. But if cells release a lot of virus, then the B cells, the antibodies will mop up that released virus.
Narrator: The adaptive immune system includes special white blood cells known as T cells and B cells, along with the antibodies they produce.
Here's how it works: The T cells play a key role in guiding the B cells. They tell the B cells which antibodies should be produced more.
Dr Bourke: The second time you get the virus, you'll actually have antibodies waiting there because you've got a memory response. So, when that virus comes in, they will bind to the virus and stop it getting into the cell and you won't get as sick the second time.
Narrator: This memory helps us to get immunity from some illnesses.
And this power of our adaptive immune system is the inspiration for vaccines.
A vaccine is a special kind of medicine. It helps protect us from certain diseases by teaching our body to fight them.
Vaccines have tiny parts of the germs they protect against, like bacteria or viruses. This helps our body learn how to defend itself without actually getting sick.
Dr Bourke explains that vaccines are like a training exercise for our immune system, but without the risk of catching the disease.
Dr Bourke: The key principle of a vaccine is that you get, your body or your immune system gets to see proteins from a pathogen, but not on a pathogen that's going to cause you disease. It's a part of it. So, there'll just be a protein, might even just be the protein itself, like a surface protein. For instance, the coronavirus vaccine, the different platforms of vaccine, ultimately what they all do is produce a spike protein.
And the spike protein is the key that the virus binds to get into the cells. So, if you put an antibody in the way and stop the virus binding to the spike protein, that's called protective immunity. All the vaccines we've got generate spike proteins so the immune system can see it and select out the antibodies you've got that recognise it and expand that population so you've got a memory response to the spike protein. So, when you get the real virus, you'll bind to the spike protein, and it won't be able to get into the cells.
Narrator: Antibodies really are powerful. But it’s not just in the body that they’re useful. There are also other ways the power of antibodies can be used – including in diagnostics and treatment.
Dr Bourke: We can take a patient's serum with antibodies and see if it binds to a pathogen, which will tell us they actually were exposed to it in the past, they've got a memory response to it. We can also use it in therapeutics. So, with autoimmune disease, we target signalling proteins that cause inflammation. So, we have antibodies that actually bind to our own proteins and switch off inflammation. And also in cancer, we've got antibodies that will bind to the surface of cancer cells and direct the immune system to kill those cells.
Narrator: An assay, not to be confused with an essay, is a special kind of lab test that uses antibodies.
You can test a person's blood to see if their antibodies react to certain antigens to find out if they've been exposed to specific infections.
A common test you might know is the one for COVID. Although, one challenge with these tests is figuring out if someone's antibodies came from having the actual COVID infection or from a COVID vaccine.
Narrator: Let’s recap: antibodies have three big roles. They fight infections, help diagnose diseases in labs, and are used in treatments through something called monoclonal antibodies, targeting specific proteins.
But what if someone has low antibodies or they aren't working right?
There are several reasons why someone might have low antibodies. It could be due to cancer treatments, or they might have a condition from birth that stops them from making enough antibodies, or any at all. This can make them more likely to get infections.
In such situations, patients might need a special treatment called intravenous immunoglobin, which comes from donated blood. This treatment is rich in igG antibodies, which helps boost their immune system.
Dr Bourke: So, antibodies only last a certain amount of time and then they're broken down by the body. That's why you have B cells that keep pumping them out. So, when we give somebody pooled antibodies from elsewhere, they eventually break down. They last about 20 to 30 days, which is why people get an IV every four weeks.
Narrator: If you're interested in learning more about blood donation and how antibodies treatments can save lives, check out our Blood Donation episode from earlier this season.
According to Dr Bourke people with low levels of antibodies might be more at risk for autoimmune diseases. These include conditions like celiac disease or Rheumatoid Arthritis.
Dr Bourke: So, the auto means against yourself, automatically directing against yourself. So, it’s an abnormal immune response. And it's sort of a, it's a dysregulation of the immune system. So normally the immune system can tell very clearly the difference between your proteins and the proteins of a pathogen. But in autoimmune diseases, we think it gets confused and then you start generating either antibodies or T cells against your own proteins. And that can lead to inflammatory problems, for instance, rheumatoid arthritis if it's affecting a joint or celiac disease if it's affecting the bowel or the small bowel. So, these are dysregulated immune responses that end up with inflammation that shouldn't be happening because your immune system is attacking parts of yourself.
Narrator: So, what does it mean to live with an auto-immune disease?
Cheryl was officially diagnosed with rheumatoid arthritis in her mid-thirties. But she’d experienced symptoms, such as severe joint pain and swelling since she was in her teens.
Cheryl: My name's Cheryl Dines. I live in Brisbane in Queensland and I'm 51.
So, rheumatoid arthritis is an autoimmune disease. So, it's different from say osteoarthritis, which is wear and tear on your joints. I've had surgery on my wrist because the tendons got affected by the disease. So, it's really sort of a lot different to what most people think when they think of arthritis.
Narrator: In rheumatoid arthritis, the immune system attacks the lining of the joints by mistake. This lining, called the synovium, makes fluid for smooth joint movement. But when it gets inflamed, it causes pain, swelling, and redness. This inflammation can even damage the bones and change the shape of the joints.
It doesn’t just affect joints like hands, knees, and wrists, but can also harm the eyes, lungs, skin, heart, and blood vessels.
The exact cause of rheumatoid arthritis isn't clear, but it seems to be a combination of genetics, environment, and hormones.
People with this condition have 'flares' when the symptoms get worse. These flares can last from days to months and can be really tough to deal with.
Cheryl: So, my flare ups can range from a couple of hours to many weeks to months. So, it just, I can't determine how long it's going to last. I also get this feeling of really just being unwell with the flare ups. So, you just feel, it's almost like you're getting the flu, that feeling of just you don't want to move. It's just everything's just really hard.
The pain for me is quite severe and it often means that the joint that's flaring has to be completely immobilized and not move. And with me it gets into all of my joints so I don't have a joint that doesn't get affected so even my jaw will flare up from time to time. So it's a matter of managing the pain I suppose by keeping it still, applying heat, pain relief if that’s going to work and if it gets really bad so sometimes I have to go and have cortisone injections straight into the joints just to give me some relief if it's going on for too long.
Narrator: Cheryl manages her condition with daily medication and exercises to keep her body active and her joints strong. But dealing with an autoimmune disease isn’t just about the physical effects. Cheryl finds it really helpful to join support groups for her condition. These groups let her connect with people who truly understand what she's going through.
Cheryl: Initially, it's really confronting and really quite scary when you first get diagnosed with something like this. Arthritis Queensland have a program for peer, they call it a peer mentor program. It's called Arthritis Assist. And that's where you get to speak to somebody else who's had the disease. And from my own personal experience, speaking to other people who have the disease is just, it really does make such a difference to be able to talk to someone who can tell you that it's going to be okay, because sometimes you just don't feel like it's going to be okay because it's really, really hard.
But I also have a really great group of friends and family around me so they, if I'm stuck at home for a few days, someone will arrive on my doorstep with coffee and cake. So it's really important to have those people around you who don't mind if you cancel.
Narrator: Another tip for family and friends? Avoid offering ‘cures’ you’ve heard about, however well-intentioned.
Cheryl: I can't count the number of ‘you need to take fish oil every day and then you'll be better’ or ‘you need to add turmeric as your supplement and that will make you better’ and people don’t understand that it’s my immune system that’s going crazy and it's not that I just need some more sort of lubricant in my joints and everything will be okay.
Narrator: Right now, there's no cure for rheumatoid arthritis. The focus is on finding treatments and medications to manage the disease. Since everyone's different, a treatment that helps one person might not work the same for another. One treatment option uses those monoclonal antibodies we talked about earlier. Remember, these are special proteins made in a lab that work just like the antibodies in your body.
Dr Bourke: Yes, there's been a range of antibodies used in rheumatoid arthritis. The most common target for those or antigen is a molecule called TNF, which is part of the immune inflammation response in the joints. So, if you take TNF out of the system, the inflammation settles down. And so there's a range of antibodies and monoclonal antibodies that can be given that block TNF or they bind to TNF. And so it can't work in the immune response. And when you, it was found that when you take those, when you take TNF away by antibodies, the rheumatoid arthritis can be switched off really.
Narrator: To keep our antibodies and immune system healthy, it's really about sticking to the basics: stay active and eat a balanced diet that’s limited in processed foods.
These simple steps can make a big difference.
Dr Bourke: So, it's very important to have a broad natural food diet. Exercise is also important to improve your circulation and there's evidence to show that exercise helps improve immune function. And then the other key point is that people should use vaccines when they're indicated. So if you're at risk of being exposed to a particular pathogen and there's a vaccine for that, we really recommend that you have it. So that means people travelling or in this case with seasonal flu or the coronavirus.
Narrator: And one final question before we let Dr Bourke go. Why is it that some vaccines we only need to have once, but others have to be updated each year?
Dr Bourke: Mainly that's a function of the actual pathogens. So, measles is a virus that does not change much over generations, which is why if you get if you either get measles when you're young or you get vaccinated, it lasts for most of the person's life. But things like flu and coronavirus, flu more so, flu is very changeable, so every season the flu looks quite different.
So, immunity from a previous vaccine or even the previous flu illness does not necessarily protect you against the next flu that's coming through. So, you need to be vaccinated with flu on a yearly basis.
Narrator: Thank you for listening to this episode of It Can’t Hurt To Ask, all about antibodies. We’ve learnt how they help protect our body from infection, what it’s like to live with an auto-immune disease, how vaccines work and much more.
Thank you to Dr Peter Bourke and the team in Cairns, and Cheryl Dines for sharing their expertise and story with us.
We’ve got more blood-related health topics you can dive into, including blood donation, mosquito-borne viruses, blood cancer and periods.
If you want to learn more about the immune system, you can also listen to our dedicated episode in our previous podcast, My Amazing Body. We’ll add a link in shownotes so you can jump right in.
New episodes of It Can’t Hurt To Ask drop every week.
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