The symptoms of Retroperitoneal Fibrosis (RPF) are often not specific. Occasionally patients are diagnosed incidentally before they develop any symptoms.
When symptoms do occur, the more common ones include:
- Pain – usually abdominal, flank, lower back pain, or into the groin or scrotum.
- Weight loss
- Fevers / night sweats
- Lack of energy
- Recurrent urine infections
- Joint pains
- Loss of appetite
It is quite common for pain, weight loss, lack of energy and sweats to occur together.
RPF typically affects adults, rather than children. It is more common in males than females (54-77% of cases are in males; Vaglio and Maritati, 2016). It is a long term condition. There can be periods when the disease becomes inactive but it may later reactivate.
Most people with RPF lead normal lives. However, there may be complications. For example RPF can lead to kidney disease and high blood pressure. (See How the Disease Works below) Neither of these complications may cause symptoms until very late. They should be identified as soon as possible because they are treatable. This is why long-term follow-up by a specialist team is important.
RPF is often first detected by imaging tests. It may be suggested by an ultrasound scan of the kidneys, but computed tomography (CT) or magnetic resonance imaging (MRI) gives more detail. Blood tests will be required to check kidney function and look for possible underlying causes.
A tissue sample (biopsy) may be required to confirm a diagnosis in some cases. If so it is usually done as a day-case procedure. A scanner is used to identify the affected area in the back, and a biopsy needle is guided into position. A small sliver of tissue is taken and examined in the laboratory. Although this type of biopsy is generally very safe, a small risk of complications exists as it does with most clinical procedures.
A biopsy does not always guarantee enough information to confirm a diagnosis. For these reasons, the anticipated advantages versus disadvantages of a biopsy are weighed up in each case. The decision to proceed to biopsy or not, is taken through discussion between the specialist doctor and patient (plus family and carers if requested by the patient).
Treatment The aims of treatment are:
- to slow down the inflammation and scarring process,
- protect kidney function,
- reduce pain and
- avoid complications
Each case of RPF is different and there are a number of treatment options. Treatment options need to be discussed in detail between the patient and the medical team. This allows the patient to make the right choice for themselves.
An overactive immune system may be the underlying cause of RPF in some cases. If so, medications to dampen down the immune system such as steroids (e.g. prednisolone) or other immunosuppressive medications may be used. Research studies suggest that steroids can reduce the RPF mass size by around 50% in up to 95% of cases but this has to be balanced with the risk of long term steroid side effects including weight gain, diabetes, fragile skin and weakened bones (Vaglio and Maritati, 2016; Fernando et al., 2016).
Although some centres report better outcomes with other drugs such as mycophenolate mofetil (MMF), the findings are not consistent between reports. Research is underway to understand which drugs may work best and provide the least amount of side effects. The RaDaR Rare Disease Registry represents a part of that research activity – below see What’s new? Opportunities for research and development below.
A healthy lifestyle – including regular mild exercise, achieving ideal body weight, avoidance of smoking and following a nutritious diet – is important for all individuals but in some cases of RPF, blood vessel disease may actually drive the condition. For this reason, it is extremely important for patients with RPF to adopt a healthier lifestyle and their specialty doctors and community general practices should be able to advise and help with this.
The fibrosis of RPF can compress the ureters and block the flow of urine from the kidneys (see How the disease works below). If this occurs, urine flow can be restored using a stent. The stent, a slender tube, is inserted in the ureter holding it open for urine to flow freely. This is usually done in a minor operation under general anaesthetic (GA; where you are put to sleep under the care of an anaesthetist). A urologist guides the stent into position using a ‘telescope’ inserted into the bladder.
If a kidney is severely blocked it may be necessary to drain it with a tube placed straight into the kidney through the skin at the back (nephrostomy). This is usually a temporary measure, and can be followed by using a stent. Stents do need changing every few months as they are prone to silt up.
A long-term solution to ureteric obstruction is an operation called ureterolysis (Fernando et al., 2016). This allows a patient to be stent–free and may provide the best relief of obstruction in selected cases. It is a big operation and may require several days in hospital and a number of weeks of recovery at home.
Rarely, major blood vessels too can become blocked or weakened in RPF. If so, stents specifically designed for blood vessels can be used to protect blood flow and reduce the risk of internal bleeding.
It is important for people with RPF to be seen regularly by a multidisciplinary team of specialists. At different times they may need the advice of nephrologists (care of kidneys and blood pressure), radiologists (imaging), rheumatologists (immune system), urologists (to protect urine flow) or vascular surgeons. In the out-patient clinic, symptoms will be reviewed, kidney function will be tracked using a simple blood test, and any changes in medication or management of the condition can be planned. Coping strategies and life-style advice should also be available.
The RPF Rare Disease Group have recently conducted a patient focused online study to understand the un-met medical need of patients with retroperitoneal fibrosis. The results of the survey were presented at UK Kidney Week 2017.
UK Kidney Week 2017 RPF Patient Survey Poster – James Tomlinson et al, Clinical Lecturer in Renal Medicine, Institute of Clinical Sciences, Imperial College, London
There is an active online international RPF community (over 600) organized by RPF patients and their families. This includes online postings and chats for people to openly discuss their experiences with fellow RPF sufferers.
There is also a moderated international Facebook group .
Guys Hospital, London has its own patient support group for RPF
The retroperitoneum is the term given to the part of the body behind the abdominal cavity and in front of the back muscles and back bone. This is where the main artery (aorta) and vein (vena cava) lie, taking blood to and from the lower half of the body. The tubes that drain urine from the kidney into the bladder (ureters) also run through this region.
RPF is a distinctive pattern of disease in which fibrous, scar-like tissue develops in this region surrounding the blood vessels and ureters (see Figure One below)
Figure One: Areas commonly affected by RPF
The cause of RPF is not known, and it seems likely that several different factors play a part. Furthermore, these can differ between individuals. In some there is a problem with the regulation of the body’s immune system. For example, there is an association between RPF and IgG4 Disease. This is a rare condition of the immune system that can inflame different tissues in the body. IgG4 disease can be diagnosed with a blood test. If positive, treatment for a patient with RPF can be targeted to the underlying immune problem.
In other patients inflammatory or degenerative conditions of blood vessels (such as Primary Vasculitis or atherosclerosis respectively) can be a cause, or simply make matters worse. Historically, some medications (e.g. methysergide or beta-blockers) have been reported to be associated with development of RPF, although such associations have not been confirmed by more recent reviews. This is an area for further research. Smoking clearly worsens atherosclerosis. However, for a large number of people with RPF, the cause remains unknown.
Inflammation and scarring
Normally when there is a wound or an infection, the immune system identifies the affected area and it becomes inflamed. Next, scar tissue is laid down to ‘seal off’ a damaged area. Much later there is re-modeling and the fibrous scar tissue is reduced and original structures repaired.
In RPF there is inappropriate deposition of fibrous scar-like tissue, indicating a problem with the normal control of the inflammation-scarring-healing process.
The excess fibrous material tends to constrict and compress normal structures. It can be seen on scans as extra tissue most often around the aorta.
Impact on the kidneys
Scans also show if the ureters are blocked as they appear distended with urine above the blockage. If urine flow is impaired the kidney responds by reducing function. This is reversible initially (Acute Kidney Injury (AKI)). However if obstruction continues permanent damage is done and kidney function cannot return even if normal ureteric drainage is restored (Chronic Kidney Disease (CKD)).
The Retroperitoneal Fibrosis Rare Disease Group (RDG) is working with national and international partners to develop a better understanding of RPF patterns of disease, natural histories and best current treatments. We are also working with patient groups to gain their perspectives and to better understand the main issues they face relating to RPF.
To do this the RDG is registering patients with this condition in the National Renal Rare Disease Registry (RaDaR). The registry will be used to find suitable participants for future research trials into the effectiveness of new treatments. If you are interested in finding out more about the registry RaDaR or the activity of the RDG please visit the Retroperitoneal Fibrosis RDG page.
- Fernando, A., Pattison, J., Horsfield, C., Bultitude,M., D’Cruz, D., and O’Brien, T. (2016). A lot of questions (and a few answers …) in retroperitoneal fibrosis. BJU. Int. 117, 16-19.
- Vaglio, A. and Maritati,F. (2016). Idiopathic Retroperitoneal Fibrosis. J Am. Soc. Nephrol.