Ask The Nurse // 6th June 2022
Kidney problems are common complications for myeloma patients. Up to half of all patients will have some degree of kidney damage at diagnosis, and more will develop it at some point during their myeloma. The added risk of kidney disease, in addition to myeloma, can be worrying for patients and their families.
In this month’s blog, we answer some of the questions about causes, treatment, and management of kidney problems that we are often asked on the Myeloma Infoline.
What is kidney disease?
Kidney disease is a condition where the kidneys are not working as well as they should. It is common and can affect anyone; however, myeloma and anti-myeloma treatments can increase the risk of kidney disease.
The severity of kidney disease can vary depending on the level of kidney damage and how well the kidneys are functioning. It can range from a mild condition with no or few symptoms, to a very serious condition where the kidneys stop working, sometimes called kidney failure.
The symptoms of kidney disease include:
- Persistent headaches
- Loss of appetite
- Nausea and/or vomiting
- Changes in urination frequency (can be either more or less often)
- Changes in volume of urine (can be excessive urine or very little to no urine)
- Swollen feet and ankles
- Shortness of breath
How can myeloma affect the kidneys?
When the kidneys are put under additional strain, they can become damaged, resulting in kidney disease.
There are several reasons myeloma patients can develop kidney disease and there may be more than one contributing factor.
In myeloma, most cases of kidney disease (8 in 10) are caused by:
- Using non-steroidal anti-inflammatory drugs (such as ibuprofen or diclofenac)
- High calcium levels
Very rarely, myeloma treatments and antibiotics can cause kidney problems.
Sometimes kidney disease can be caused when the free light chains produced by myeloma cells damage the kidneys. Read our Ask The Nurse: Paraproteins and free light chains or watch our animation on myeloma kidney disease for more information.
If you are diagnosed with myeloma, your healthcare team will regularly monitor you through blood tests and kidney function tests.
How would I know if my kidneys are working properly?
Your kidney function is regularly monitored using blood tests; your healthcare team will continuously be checking this for you.
The most common kidney function test is monitoring the levels of a molecule called creatinine. Creatinine is a waste product normally filtered out by the kidney and passed into the urine. A high creatinine level indicates that the kidneys are not working normally.
The creatinine level is combined with your age, gender, and ethnicity to provide a more accurate measurement of kidney function. This is called an estimated glomerular filtration rate (eGFR).
Blood tests for your white blood cell count and calcium levels and urine tests can also indicate how well your kidneys work.
How is kidney disease treated?
The treatment for kidney disease can depend on the cause.
The first treatment for kidney disease will often be to treat the myeloma itself. This can allow the kidney function to recover by reducing the free light chain and/or calcium levels in the blood.
Other treatments may include:
Treating urine or kidney infections rapidly.
Bisphosphonates: such as zoledronic acid (Zometa®) to reduce your calcium levels if your blood tests show these are high (hypercalcaemia).
Erythropoietin (EPO): a hormone produced in the kidneys that helps maintain red blood cell levels. If patients have kidney disease, the kidneys may not produce enough EPO, leading to anaemia.
Avoiding NSAIDs as painkillers: they are not recommended for myeloma patients because they are toxic to the kidneys. The drugs which should be avoided are:
- High-dose aspirin (usually 300mg)
Dialysis: a procedure which removes waste products from the blood when a patient’s kidneys have stopped working.
Will my kidneys get better?
If kidney damage is caught early, kidney function can recover. Most people with kidney disease improve with treatment, so dialysis is not usually needed.
Only 1 in 30 people with myeloma and severe kidney damage require dialysis, which is usually temporary.
Is there anything I can do at home to help look after my kidneys?
The following steps can help keep your kidneys as healthy as possible:
- Do not smoke
- Eat a varied diet (particularly avoiding added salt)
- Do regular, gentle exercise
- Drink plenty of fluids (unless otherwise advised)
- Avoid taking NSAIDs
- Tell your healthcare team about any signs or symptoms of kidney damage as soon as possible
If you already have kidney disease and are having dialysis, you will be given specific advice about diet and fluids and dealing with side effects but talk to your healthcare team if you need further information or support.
If you have any questions about myeloma and kidney disease, read our Myeloma and the Kidney Infoguide. You can also watch our Digital Infoday Session on Myeloma and the Kidney.