Multiple myeloma is a rare type of cancer of the blood. Myeloma affects the plasma cells in the blood, which are responsible for fighting off infections, thus making the body more susceptible to all types of infectious diseases. As the cancerous cells of multiple myeloma grow and spread throughout the body, they start causing bone damage at different places along with several health complications. One of the most affected organs by multiple myeloma, other than bones and blood, are your kidneys. Kidney failure is known to be a common complication of multiple myeloma. So, is there really a link between multiple myeloma and kidney failure? And if so, what is this connection that causes your kidneys to fail? Read on to know more.
Is There a Link Between Multiple Myeloma and Kidney Failure?
Myeloma kidney is a term used to refer to the accompanying kidney failure in multiple myeloma patients. Kidney failure is one of the most common complications of multiple myeloma. It has been observed that at the time of diagnosis, nearly 30 to 40% of patients with multiple myeloma also end up having some percentage of kidney failure or kidney damage. But what is the link between multiple myeloma, which is a blood cancer, and kidney failure?
It is believed that multiple myeloma affects the kidneys in many ways. Myeloma cancer can have an impact on the filter of the kidneys, also known as the glomerulus, the pipes of the kidney known as the tubules, or the actual kidney tissue itself, which is known as the interstitium.
In order to understand the link between kidney failure in multiple myeloma, one needs to understand the structure of the kidney first. The tubules of the kidney are the pipes through which the body’s filtered blood gets transformed into urine and then exits the body as waste. There are many filters present in the kidney, known as glomeruli. The blood passes through these filters and enters the pipes or the tubules. When you suffer from multiple myeloma, the cancerous plasma cells begin to make abnormal proteins instead of what they are supposed to be making. These abnormal proteins end up traveling through the tubules of the kidney to combine with another protein type that is present in urine. This protein is known as Tamm Horsfall protein.
When the abnormal proteins join up with Tamm Horsfall protein, they end up becoming too large to pass through the kidney’s tubules and are unable to exit the kidney through urine. These ultimately result in blockages inside the pipes, preventing any fluid to pass through. It is these blockages that over a period of time result in kidney damage. The combined proteins inside the tubules also give rise to an inflammatory reaction within and around the kidney tissues.
Kidney failure which occurs due to these blockages in the tubules is referred to as myeloma kidney or cast nephropathy.
Additionally, multiple myeloma also causes calcium levels to increase in the blood. Elevated levels of calcium can also have an effect on the kidneys, causing damage. This is because high calcium levels cause crystals to form inside the kidneys leading to kidney damage. 1
Certain medications for multiple myeloma, such as NSAIDs (naproxen and ibuprofen) can also damage the kidneys.
Can Myeloma Kidney or Kidney Damage from Multiple Myeloma be Treated?
Treating kidney disease that is associated with multiple myeloma depends on what the treatment for multiple myeloma is being given. Patients who have multiple myeloma are usually treated with chemotherapy and/or transplant of bone marrow. Bone marrow transplant, though, is only advisable for those patients who still have good mobility and do not have severe damage to the kidney or the liver. You should also not be suffering from any type of heart disease.
For patients undergoing chemotherapy, the commonly used medications include prednisone, melphalan and thalidomide. Chemotherapy helps treat kidney damage associated with multiple myeloma as well because it decreases the production of the abnormal proteins by the plasma cells.2 This reduces the overall levels of the abnormal proteins present in the bloodstream, which over a period of time gives the kidneys a chance to recover.
Apart from chemotherapy, there are certainly other factors also that can help patients who have myeloma kidney. Staying hydrated is one of the most important things you can do to help your kidneys. Dehydration leads to more blockages being formed in the tubules, so drinking at sufficient amount of water in a day is recommended to prevent multiple myeloma linked kidney damage.3
Avoid taking too much of NSAIDs (nonsteroidal anti-inflammatory drugs), such as ibuprofen and diuretics, such as furosemide. These medications have been shown to increase the blockages in the tubules. If you have elevated levels of calcium in the blood, then it is necessary to treat the same as high calcium levels will not get filtered through the kidney and will make the blockage worse. It is possible to treat elevated calcium levels with medications, such as zoledronic acid and pamidronate.
Instead of NSAIDs, people having myeloma kidney can opt for taking medications known as bisphosphonates that are typically prescribed in the treatment of osteoporosis. These drugs will help prevent hypercalcemia and also reduce the occurrence of bone damage. Furthermore, anti-inflammatory drugs known as glucocorticoids will also help in reducing cell activity. Dialysis can also help ease the strain on the kidneys in patients suffering from multiple myeloma.2
Kidney failure is one of the most common side effects of multiple myeloma. Damage to the kidneys can be minimized if the multiple myeloma is caught early and treatment is started in the early stages itself. There are some treatment options available for helping reverse damage to the kidneys caused by multiple myeloma. However, remember that if you have multiple myeloma, then keeping yourself well hydrated will be best for keeping your kidneys as healthy as possible, in spite of the cancer.