What is LPHS?
Loin pain haematuria syndrome (LPHS) is a very rare condition that causes severe pain in the loins or flanks (the part of the lower back below the ribs and above the pelvis) and blood in the urine (haematuria).
LPHS affects around 1 in 1,000,000 people in the UK. It was first identified in 1967 but there has been very little research on the condition so it is not well understood. It usually affects young adults, with an average age of diagnosis of 30. Around eight out of ten people with LPHS are women.
As LPHS is very rare in people over the age of 60, it is possible that the condition resolves itself over time.
What causes LPHS?
The causes of LPHS are not currently known.
Researchers believe it there may be linked to having an abnormally thick or thin glomerular basement membrane (the layer of tissue in the kidneys that filters the blood) but this has not yet been proven in all cases.
In some cases, LPHS occurs after a urine infection, although the pain may continue even when the infection itself has been successfully treated.
One in two people with LPHS have a history of kidney stones but the exact link with LPHS is currently unknown.
As LPHS is much more common in women than men, it may be linked to the changes in a woman’s hormones during her menstrual cycle, or because women tend to have a thinner glomerular basement membrane. However, this relationship is not yet fully understood.
What are the signs and symptoms of LPHS?
There are two main symptoms of LPHS:
- Severe pain in the loins, on one or both sides of the body. The pain may be continuous or come and go in waves. It is often worse at night, as lying down puts pressure on the loins. For some people, the pain is worse after exercise.
- Haematuria (blood in the urine). This may be visible to the naked eye or only able to be seen under a microscope.
Most people with LPHS have both the pain and the haematuria but some people may only have one of these symptoms.
Other possible symptoms include:
- low fever
- feeling or being sick
- pain when passing urine
How is LPHS diagnosed?
LPHS is diagnosed by ruling out other conditions that have similar symptoms, such as IgA Nephropathy, Autosomal Dominant Polycystic Kidney Disease (ADPKD) or kidney stones.
The symptoms of LPHS are also similar to those of a urine infection, so a urine test is often used to rule this out.
Examining the urine under a microscope can identify the haematuria. If this is severe, a kidney biopsy may be recommended to check for any abnormalities to the structure of the kidneys.
An angiogram imaging test can examine the blood vessels in the kidneys to see if they are abnormal in some way.
A CT scan may be recommended to look for any evidence of kidney stones.
Does LPHS affect other parts of the body?
LPHS is only known to affect the kidneys.
Does LPHS run in families?
There is currently no evidence that LPHS runs in families.
How is LPHS treated?
There is currently no cure for LPHS so treatment focuses on symptom management.
Painkillers may be prescribed by your healthcare team to minimise loin pain. Non-opioid painkillers such as paracetamol are usually tried first. If these are not effective, opioids such as codeine may be prescribed with careful monitoring.
If the pain is very severe, a paravertebral nerve block may be considered. This is an injection into the nerves of the spinal column to block pain receptors. A referral may be made to a specialist pain service and psychological support programs may also be recommended.
Blood pressure medications known as angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) may be prescribed to reduce the pressure within the kidney’s filter units (glomeruli).
Antibiotics may also be prescribed if there are any signs of infection.
In rare cases, surgery may be considered to disconnect the kidney’s nerves. There are two possible procedures, both of which take place under a general anaesthetic, using laparoscopic (keyhole) surgery.
- Renal autotransplantation moves the kidney and ureter to a new location in the pelvis. This is not the same as a kidney transplant, as the patient’s own kidneys are kept and continue to function normally, just in a different location.
- Renal denervation cuts away the nerves from the kidney’s artery and vein, and clips them so that they do not grow back. At the moment, renal denervation can only take place as part of a research study as it is not fully understood how effective the procedure may be.
In most cases these surgical approaches to the management of LPHS are not recommended however, due to the potential for complications and the likelihood that LPHS will resolve itself over time.
Every individual is different and your healthcare team will discuss the best treatment options for you.
Although the loin pain can be very severe, kidney damage does not occur and LPHS does not lead to kidney failure.
Where can I get more information or support about LPHS?
We are not aware of any UK-based support groups for LPHS. If you know of any LPHS patient groups, please let us know so we can share their details.
Publication date: 08/2024
Review date: 08/2027
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