Kidney failure, which affects 20 percent of all multiple myeloma patients, is a serious complication that can lead to permanent kidney impairment and continued reliance on dialysis. However, a wide range of treatment options is available to myeloma patients experiencing kidney failure. Successful treatment methods include rehydration, correction of hypercalcemia (a condition that results in high serum calcium levels), and discontinuation of non-steroidal, anti-inflammatory drugs (such as aspirin or ibuprofen), that reduce blood flow to the kidneys.
A common complication found in myeloma patients experiencing kidney failure is hypercalcemia, a disorder that occurs when a patient’s damaged bone dissolves and creates an overabundance of calcium in the bloodstream. The kidneys need to overwork to process the extra calcium, and this typically leads to kidney failure. Treatment for hypercalcemia frequently requires administration of intravenous fluids and prednisone, a steroid that indirectly lowers blood calcium levels.
Patients with kidney failure may also be prescribed allopurinol (Zyloprim), a drug that lowers blood levels of uric acid. The increased number of malignant plasma cells produces uric acid, which damages the kidneys, as a waste product.
High levels of production and excretion of free light chains, which damage the kidney tubules, may also cause kidney failure. Light chains comprise part of the structure of monoclonal proteins, which are antibodies present in high concentrations in myeloma patients. When light chains enter the blood stream unattached to the heavy chains, they are then referred to as free light chains, and can impair kidney function.
One possible treatment for high levels of free light chains is blood plasma exchange to remove the protein from the blood. However, two small, randomized clinical trials studying this form of treatment produced conflicting results. No conclusive evidence has been found to indicate that this is a successful form of treatment (related Annals of Internal Medicine article).
Novel therapeutic agents are another treatment method for kidney failure. The VDD drug regimen, consisting of Velcade (bortezomib), dexamethasone (Decadron), and doxorubicin (Adriamycin), has alleviated kidney impairment in multiple myeloma patients.
A recent Phase 2 clinical trial determined that the VDD regimen resulted in improved kidney function for 62 percent of patients, and overall survival for these patients was 64 percent after two years of treatment. Side effects observed in patients on the VDD regimen included diarrhea, gastrointestinal bleeding, infections, low white blood cell count, cardiovascular problems, weakness, and low blood platelet count and hearing loss (related Beacon news).
If impaired kidney function has progressed to severe kidney failure, treatment options may be limited to hemodialysis, peritoneal dialysis, and autologous hematopoietic stem cell transplants. These advanced stages of kidney failure are usually not reversible, even if the multiple myeloma responds to treatment. In these later stages, approximately 5 percent of myeloma patients remain dependent on dialysis.
In hemodialysis, often referred to only as “dialysis,” the patient’s blood is pumped through an external machine which takes over the kidney’s function, i.e. it removes waste products from the blood. Hemodialysis may be completed at a dialysis center or at home (often while sleeping). A common complication found with hemodialysis is low blood pressure, although infections or development of blood clots may also occur.
Researchers have also been testing a treatment that combines chemotherapy and a new procedure called high-cutoff hemodialysis. This procedure removes immunological proteins that may damage the kidneys. A small-scale clinical study in England found that 70 percent of patients no longer required dialysis treatment following the procedure. These results suggest that high-cutoff hemodialysis is highly effective, though the results are being further evaluated in a randomized controlled trial (related Beacon news).
An alternative form of dialysis, called peritoneal dialysis, is often completed by the patient or a family member at home. The procedure introduces fluid into the abdomen, and water, salts and waste products from the blood are removed from the body through osmosis. This method may be done manually, up to four or five times a day, or it may be completed automatically with a machine while the patient is sleeping. Patients often choose to use peritoneal dialysis because it allows patients to more easily continue a regular work and social schedule, especially if the dialysis exchanges are completed at home during sleep. By comparison, hemodialysis is more commonly completed at a dialysis center, which has the potential to interrupt a normal daily schedule.
Another option, autologous hematopoietic stem cell transplantation (auto-HSCT), may completely reverse kidney failure in up to one-third of myeloma patients. Auto-HSCT replaces stem cells that are killed during chemotherapy with stem cells collected from the patient’s bone marrow prior to treatment with chemotherapy. Auto-HSCT has associated complications of infection, inflammation, severe liver injury, and a 10 percent mortality rate. As a result, many myeloma patients are ineligible for treatment with auto-HSCT (related Beacon news).
Kidney failure may also restrict myeloma patients from undergoing some standard myeloma treatments, such as aggressive or high-dose chemotherapy treatments. The failing kidneys are unable to quickly remove the treatment’s chemicals from the body, potentially creating a dangerous and highly toxic build-up in the patient’s blood. In particular, kidney failure increases the amount of time that Revlimid (lenalidomide) stays in the patient’s bloodstream, so lower doses are necessary to reduce side effects (related Beacon news).
For more information on kidney failure in multiple myeloma patients, please see the other Beacon articles in this series and related Beacon news articles.