Myeloma renal disease is a condition caused by long term effects of multiple myeloma. "Renal" refers to the kidneys, which is one of the many body systems that can be harmed by multiple myeloma. The disease creates a great burden on the kidneys in a variety of ways. You are probably aware that the malignant plasma cells in the bone marrow produce an antibody that is released into the bloodstream. This antibody is a protein and there can be very high levels of protein in the blood of myeloma patients.
Additionally, multiple myeloma can cause the breakdown of bone and the subsequent release of excess calcium into the bloodstream. The kidneys work to filter the body's blood supply and the excess protein and calcium that are present in the blood can put a "strain" on the kidneys. They have to work exceptionally hard to filter the abnormally high levels of protein and/or calcium in the blood. These conditions can cause "renal dysfunction" or "renal insufficiency," which means that the kidneys are no longer able to handle their jobs. In severe cases, this can lead to renal failure, which means the kidneys are shutting down. Patients may have to undergo dialysis so machines can perform the blood filtering function for the body.
How can you help to protect your kidneys? An important thing to remember is that you should not let yourself become dehydrated. It is crucial that you stay well hydrated (e.g., making sure you drink enough plain water) as this will continuously flush your kidneys which will help them function properly. You should avoid taking NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen and naproxen and you should avoid IV contrast dye (particularly the IV dye used with CT scans) as these substances are taxing to the kidneys. You will want to seek advice from your oncologist before using these substances.
If it is noted that you are hypercalcemic (have a high level of calcium in your blood as determined by a blood test), then your physician will want to treat you without delay to lower your calcium level so that the kidneys are not damaged. We are also going to check your kidney function before administering bisphosphonates, which are the bone-strengthening agents used in multiple myeloma patients. These drugs are excreted by the kidneys so if your kidneys are not functioning optimally, you may need dose adjustments of these drugs or your physician may choose not to administer these agents.
It is important to note that those patients with myeloma renal disease can take actions to relieve some of the burden on their kidneys. There are many treatment options available for myeloma patients and many patients will also see an improvement in their kidney function as the disease is controlled.