Impact of Anemia & Hemolysis in Sickle Cell Disease - Episode 6
Sophie M. Lanzkron, MD, MHS, and Jeffrey D. Lebensburger, DO, MSPH, comment on renal complications and outcomes that can result from sickle cell disease.
Sophie Lanzkron, MD, MHS: When we think about the specific organs that are affected in a chronic way, we think about renal function and renal dysfunction as being 1 of the key organs affected by sickle cell disease. The effect of sickle cell disease on organs is the effect on the kidney where people are unable to concentrate their urine at a very early age. As people get older, there’s the increased risk of more renal damage and that 1 of patients’ first manifestations could be the development of proteinuria. We know that the creatinine is not a good measure of renal function in patients, and the recommendation is to screen patients annually starting at the age of 10 for evidence of proteinuria. The kidney is so affected because the renal medulla is 1 of the most hypoxic parts of the body. It’s not surprising that in this environment, that you will have more sickling and potentially more renal damage. Years ago, the most common cause of death was related to infection, but now there’s some growing evidence that it’s not necessarily infection but pulmonary disease as well as renal disease that is a large culprit in mortality in patients with sickle cell disease.
Jeffrey Lebensburger, DO, MSPH: Patients with sickle cell disease are at high risk for renal disease. It’s a leading cause of morbidity and mortality in adults. We know that we’re all born with a certain amount of renal reserves, so this is our ability for our kidneys to work. Every day, we lose a little bit of our kidney reserve. Many of us will go through our entire life still having enough nephrons never to demonstrate any evidence of renal disease. In sickle cell disease, there’s marked kidney disease and the reason is because the kidney is in an environment that’s hyperosmotic and hypertonic and has very poor oxygen supply to the kidney. This leads to more kidney injury. We can undergo a kidney transplant. We can donate a kidney to a family member or to somebody else. That means that when we donate part of our kidney, 50% of our kidney is gone. We can live the rest of our life without any complications. With sickle cell disease, we have almost 50% of our kidney likely gone by the time we’re an adult. It’s just been damaged. It becomes fibrotic. Once you get significant kidney injury, then we get to these late stages where kidneys aren’t working as well, and that leads our patients at great risk. The NIH [National Institutes of Health] Guidelines suggest that we should be screening our patients every year for abnormal albumin creatinine ratios, and we should be closely monitoring kidney function because if we let kidney disease progress to CKD [chronic kidney disease], then outcomes are going to be very poor.