Outcomes of sirolimus regimens in 65-year-old and older kidney transplant recipients: a registry-based observational study

PURPOSE

In large observational studies of adult kidney transplant recipients (KTRs) where older adults (65 years old and older) were not well represented, the mammalian target of rapamycin inhibitors (mTOR inhibitors) has poorer outcomes than the standard tacrolimus-mycophenolate-steroids (TAC-MPA-S) regimen. We conducted this study to compare the outcomes of regimens containing the common mTOR inhibitor, sirolimus (SRL) against TAC-MPA-S in older adult KTRs.

METHODS

Using the 2000-2016 Scientific Registry of Transplant Recipients, Cox multivariable regression models were conducted to analyze the patient and graft outcomes associated with regimens containing SRL, steroids (S) and cyclosporine (CSA), tacrolimus (TAC), or mycophenolate (MPA) vs. the standard (TAC-MPA-S) regimen in older adult KTRs.

RESULTS

Included in the analysis were 15,008 (95.19%) older adult KTRs on standard (TAC-MPA-S) regimen, 242 (1.53%) on SRL-MPA-S, 300 (1.90%) on SRL-TAC-S, and 217 (1.38%) on SRL-CSA-S. Compared with the standard regimen, the adjusted risks of all-cause death and overall graft loss over a maximum 5-year follow-up were highest with SRL-MPA-S, intermediate with SRL-TAC-S and not significantly different with SRL-CSA-S. The adjusted risks of all-cause death and overall graft loss were modified by a pre-transplant history of malignancy in older adult KTRs on SRL-TAC-S, not in those on SRL-MPA-S or SRL-CSA-S.

CONCLUSIONS

In older adult kidney transplant recipients, SRL-TAC-S or SRL-MPA-S, but not SRL-CSA-S is associated with higher risks of death and allograft loss than standard TAC-MPA-S regimen and a pre-transplant malignancy history worsens these risks in patients on SRL-TAC-S. Confirmation of our findings by a prospective randomized trial is needed before translation into clinical practice can be recommended.

The sclerosing glomerulus in mice and man: novel insights

PURPOSE OF REVIEW

Segmental glomerulosclerosis is the end-point of a series of processes with have podocyte damage as a common denominator. This review summarizes the important advances that have been made in the past 2 years leading to the comprehension of several molecular mechanisms of regulation of podocyte physiology and pathology.

RECENT FINDINGS

From recent studies it has become clear that the dynamic cytoskeleton of podocyte foot processes has to be highly regulated to maintain cell shape and function. The importance of intracellular calcium in this process has started to be revealed, together with the channels and the organelles appointed to calcium entry and buffering.Novel data highlight the centrality and the complexity of the mammalian target of rapamycin pathways, which are implicated in the regulation of autophagy. Similarities between podocytes and neuronal cells have been extended to the process of dynamin-regulated endocytosis, and further data in mice and humans provide support to the idea that podocytes can be directly targeted by old and new drugs.

SUMMARY

Research is bringing numerous advances regarding the role of podocytes in the development of glomerulosclerosis, which can lead to novel and specific therapeutic approaches, as well as to a more rational use of drugs already in use. Consequently, renal biopsy becomes the indispensable instrument not only for diagnosis but also to precisely detect molecular therapeutic targets and guide personalized therapy.