Professor Krina Zondervan is interested in women's health conditions, particularly endometriosis. In women suffering from endometriosis, cells similar to those lining the uterus appear and flourish in areas outside the uterine cavity. Professor Zondervan studies genetic, molecular and environmental factors influencing this complex disorder.
Women suffering from endometriosis experience severe pelvic pain and may suffer from infertility. Endometrial-like cells develop outside the uterine cavity. These cells are influenced by hormonal changes and respond similarly to the cells lining the uterus. Causes of endometriosis remain unknown and treatments are limited to either surgery or the use of hormonal drugs.
Ultimately, medical research must translate into improved treatments for patients. At the Nuffield Department of Medicine, our researchers collaborate to develop better health care, improved quality of life, and enhanced preventative measures for all patients. Our findings in the laboratory are translated into changes in clinical practice, from bench to bedside.
Q: Hello Krina. What is endometriosis and what causes this complex disorder?
KZ: Endometriosis is a women's health condition affecting many women in their reproductive years. It can cause severe pelvic pain and infertility, and is caused essentially by cells which normally line the uterus, the endometrium, ending up in other sites outside of the uterus, mainly the pelvis, appearing on pelvic organs. These cells respond to hormones, which normally happens in the menstrual cycle, but in other sites of the pelvis they can cause small bleeds, adhesions etc; and it is those kinds of deposits which can cause the symptoms that women experience - very bad period pain, pain at other times and infertility as well. We don't actually know what causes it. One of the main hypotheses is that the cells appear in the abdomen by a process called 'retrograde menstruation'- when some of the menstruation debris ends up in the pelvis. This happens in a lot of women but what we don't know is why in women with endometriosis these cells are still able to adhere to the pelvic wall and actually grow.
Q: How common is this disorder in the UK?
KZ: We don't know exactly because women have to undergo surgery to see if they have the condition or not. So we don't really know in the general population but we estimate it affects about 5% of women in reproductive age, which in the UK alone would be around about a million women. To give a comparison, that is similar in terms of frequency to conditions such as asthma. So it is really common and we have no reason to believe that in other countries that figure would be any different; we are talking about millions of women in the world.
Q: Can we cure this illness?
KZ: Currently the only way to treat this condition is in one of two ways: one is through surgery- actually trying to get rid of these lesions. That's the only way you can get rid of the disease. Currently what we don't really know is in how many women the disease grows back after that. The other way of treatment is medical treatment - hormonal treatment, that produces essentially a lessening of symptoms but once you stop medication, endometriosis tends to come back. Currently we have no definite way of curing the condition.
Q: How could a better understanding of endometriosis, genetic and environmental epidemiology help us develop therapeutic options?
KZ: What we are trying to do here is to find genes that are implicated in increasing the risk of endometriosis. We know that endometriosis can run in families - this is why we're doing this research - and at the same time we're trying to see whether those genes interact in some way with environmental risk factors. We are in the relatively early stages but what we're trying to do is see if particular genes that increase your risk of endometriosis tell us something about the pathway of disease, the biology of the disease and might give us new targets for drug development.
Q: What have been the most important lines of research development in the last 5-10 years in this area?
KZ: There's been a lot of work in the last 5-10 years and as funding has increased in the last couple of years - which has been fantastic - we've been able to really further some of the work on the condition. But there is still a lot to be done. One of the major lines of work is trying to find out whether there are any what we call 'biomarkers' of the condition that we could measure. For example currently the only way to diagnose a woman with the condition is for her to undergo surgery. It would be much better if there could be a blood test for a woman to be diagnosed. Worldwide there is quite a lot of work going into trying to find particular proteins in blood or in other tissues that could distinguish women with endometriosis from those without. That's one important line of research. I think another important line which is often forgotten is to actually show the public health impact of the condition. I think it's a condition that's often ignored by the public, but women as well. I think the kind of symptoms that women experience are often seen as something that's 'part of being a woman' so a lot of women suffer in silence in that sense. Trying to raise public awareness of the condition for them to seek earlier help, for them to be diagnosed earlier, all helps. One study we are currently doing is a global study trying to look at the impact of the condition worldwide in about 15 different centres across the world. Hopefully that will also raise awareness and show what an important condition it is not just here in the UK or in western countries but worldwide.
Q: My final question today is how does your research fit into translational medicine within the department?
KZ: We're currently at the early stages of trying to find the genes that are involved in endometriosis. Once we have a better handle on that hopefully it will tell us more about the biological pathways that are involved and hopefully that will give for example pharmaceutical industries some targets that they could work on for drug development. But also within the department, there might be other researchers that could help us to translate this into a better treatment of women, and maybe prevention as well, which I think will be the best thing of all.