Issues in Renal Disease: An Update
Delicia Honen Yard
August 18 2009
Is CKD being defined too broadly and thus overdiagnosed?
Dr. Himmelfarb: The ASN per se doesn’t have a stand on this issue. But I would be very comfortable saying that the guidelines for classification and diagnosis of CKD promulgated by the National Kidney Foundation have had an overall benefit in developing a standardized approach to CKD. That said, controversy continues over whether the entire classification system for CKD should be based solely on the estimated glomerular filtration rate (eGFR) and whether, in essence, one size fits all for CKD. A number of efforts are under way to refine the CKD classification system, and many people feel that the classification scheme needs to be revised.
One major concern is whether the classification system, which doesn’t take into account age, tends to overdiagnose CKD in the elderly. Under the current system, about one third of people older than 70 will be classified as having CKD, yet it’s not clear that a high proportion of those individuals will progress to end-stage renal disease.
The CKD classification system is likely to be refined further in the future, but having the system, in my opinion, has been helpful in delineating the public health consequences of CKD.
Various drug combinations and dosages are continuously being tested in immunosuppressant regimens for renal transplant patients, but the best formula has yet to be determined. In what direction do you see this therapy moving?
Dr. Himmelfarb: There has been enormous progress in the development of immunosuppressive medications to prevent rejection of transplanted kidneys. And this has increased the choices of immunosuppressant combinations. While the short-term rates of rejection have declined, increasing attention is being paid to preventing long-term chronic allograft nephropathy or chronic rejection and minimizing the complications from immunosuppression. I think these trends are likely to continue.
Will we ever reach the point at which immunosuppressants will not be a lifetime prescription?
Dr. Himmelfarb: Within the transplant field, there are ongoing efforts to achieve what’s called tolerance, which would result in patients not having to take lifelong immunosuppressive medications. NIH has funded the Immune Tolerance Network, which sponsors studies on tolerance. So far achieving tolerance in humans has been difficult, and, at least for the time being, getting transplant recipients to continue on their immunosuppressive drugs is critically important.
What is the best approach to increasing the number of live kidney donors?
Dr. Himmelfarb: Like virtually every other organization, we would like to see increased availability of kidney transplants, and the best way to accomplish that is through educating the public about the relative safety of kidney donation. The ASN supports the Declaration of Istanbul, which promotes the idea that a kidney should not be a commodity that is bought and sold. This is somewhat of a controversial area—whether or not payments to live kidney donors would increase the number of kidney transplants that are performed.
Do you foresee the development of novel therapies that could replace traditional dialysis and transplants?
Dr. Himmelfarb: The ASN is certainly hopeful that new therapies will make our current therapies obsolete. One possibility would be the development of artificial implantable and/or wearable kidneys. Another would be organogenesis—essentially learning how to grow new kidneys.
Would you care to comment on the state of nephrology research?
Dr. Himmelfarb: Speaking as an individual, I think that many of the leading controversies in nephrology center on the lack of high-level evidence from randomized clinical trials to support practice recommendations.
Unfortunately, nephrology lags behind somewhat in performing the kind of randomized clinical trials that give us the highest level of evidence so that we can speak confidently about the best approaches to clinical practice. I don’t know why that is, but the nephrology community is attempting to address the problem. More clinical trials are currently being performed than in the past. But if we could achieve a higher level of evidence, then we could establish better consensus on how to optimize care for people with kidney disease. The ASN is, in general, a strong advocate for all kinds of kidney-disease research, including clinical, translational, and basic science studies.
Under new legislation, Medicare payments to dialysis centers will bundle medications with other dialysis services. What effect do you expect this to have on nephrology practices?
Dr. Himmelfarb: The major concern that ASN has with the legislation is to ensure that there are no unintended consequences whereby patients might be harmed because of possible underutilization of medications that are beneficial. In other words, if you’re being paid a fixed amount for the care of a patient, there could be a tendency to underutilize certain medications that may be beneficial. It’s really not on the part of the physicians: Nephrologists do not get reimbursed more or less money based on the prescription of medications for the dialysis patient. It’s the dialysis provider whose reimbursement will be affected by the prescription of medications. That’s one reason I don’t think this legislation will have a significant effect on nephrology practices; it will have a much greater effect on the dialysis provider.
