Wednesday, April 28, 2010

Kidney Biopsy in Heart Transplant Candidates?

A recent study in Transplantation highlights this issue in detail. Lot of times we have patients with severe CHF and are also going into acute renal failure due to pre renal or what we are now calling cardio renal syndrome sort of in the same fashion as hepatorenal syndrome? When do we think its just ATN or when is it intrinsic renal disease? When can we say this patient needs just a heart transplant and when a combined heart and kidney?

In this study, thirty heart transplant candidates with an GFR < 40 mL/min or proteinuria greater than 500 mg/day or a history of amyloidosis underwent kidney biopsies between June 2001 and March 2009. The renal pathologic diagnosis as well as the percent tubular atrophy and interstitial fibrosis on renal biopsy were assessed. On the basis of the biopsy results, nine patients were listed for only heart transplantation and eight patients were listed for heart and kidney.
Based on this small study, the conclusion was that renal biopsy provides useful diagnostic information to differentiate intrinsic renal disease from renal hypoperfusion and helps guide the decision for OHT alone versus combined HKT.
I think that it makes sense but the sample size here is too small to make a general statement. In general, clinically if the patient is not behaving like CHF induced hypoperfusion, most of us will get a kidney biopsy to make sure no other cause is lingering around.

Friday, April 23, 2010

Dual Liver and Kidney Transplantations

Tips from the NKF 2010 sessions

1. When to do both and when to do just Liver? It’s hard to figure this out as most of the kidney damage in liver associated kidney injury is ischemia and we don’t have good markers
2. A good strategy suggested was using biopsy as a guide and using the Interstitial fibrosis, tubular injury as a tool for seeing if they need a SLK or just a liver transplant.
3. When this strategy was used in some centers, and crt compared after going ahead with a respective transplants ( SLK or just liver), crt were 1.2 at 6 months in both groups.
4. Most common biopsy finding: ischemic ATN, followed by other primary GNs, (MPGN, IgA, FSGS, TMA) and vascular disease
5. If the patient has ESLD and is on dialysis < 6 weeks, perhaps just a liver is fine but otherwise might need a SLK. But with the biopsy method, we might achieve more accuracy

HIV and the Kidney Transplant

What I learned at the NKF 2010 , some few points.

1. A large NIH sponsored study basically showed that the outcomes of large number of patients when compared to non hiv patients transplanted was no different.
2. The 3 year follow up showed no major difference in graft survival
3. HIV disease didn’t progress either, perhaps because they didn’t get induction therapy or they were carefully selected patients or there is data that almost all immunosuppresive drugs we use has anti HIV viral activity from cellcept to CNI to sirolimus
4. The major problems people run into these transplants are drug toxicities as anti retrovirals have significant effect on CNI levels and high doses of CNI and increased intervals are needed.
5. There is usually more rejection in these patients,perhaps because of point number 5, but also perhaps because they don’t get much induction

6. Some centers are using induction with thymo, but their acute bacterial infection rates are high. Ideally, a anti CD20 induction is a good choice.

A nice website to look at is:

Obesity and Kidney Transplantation

What I learned at the NKF 2010. Some key points

1. BMI < 18 and >30 are both associated with worsening graft survival
2. Why does obesity affect transplant outcomes: The risk factors after few studies have been: increased insulin resistance, increased BP, hyperlipidemia, increased proteinuria and development of NODAT
3. There has been a higher incidence of acute rejection in high BMI patients? The reason: obesity has been associated with mild continuous chronic inflammation and increased proteinuria.
4. Should obese patients be trasnplanted? Yes as a comparative study showing how they do on dialysis still shows they do better on transplant. Yes, when compared to non obese patients getting transplanted, the risk is low, the overall benefit vs dialysis is more.
5. Should their immunosuppresion be treated differently? No real headway. When compared steroid free vs steroid + protocols in obese patients, no difference was noted in outcomes.

Sunday, April 4, 2010

Antibody Mediated Rejection Review

Check out the link to this nice review posted on a pediatric nephrology blog.
A nice read!

Bone marrow transplantation and solid organs

The recent issue of Transplantation embarks on two articles on simultaneously doing a bone marrow transplantation and pancreas and islet cell respectively.
The first paper is a basic science study that showed bone marrow derived pancreatic cells are mobilized into injured pancreatic tissue and contribute to β-cell regeneration. Transplantation of BM-derived cells improved the function of injured pancreas, although the response is not sufficient to restore sustained normoglycemia is their conclusion.
The second paper was on islet cell transplants, another basic science study. Cotransplantation of bone marrow cells with islets was associated with enhanced islet graft vascularization and function in this paper.

This concept of bone marrow transplantation along with solid organs is not novel now. It was first reported few years ago in NEJM of actual 5 cases of kidney transplants along with bone marrow and the need for immunosuppresion was eliminated in these patients.  This is true thinking out of the box. Long terms outcomes of these patients is still underway.