Five-Year Follow-up After Late Conversion From Calcineurin Inhibitors to Sirolimus in Patients With Chronic Renal Allograft Dysfunction

Long-term safety and efficacy of antithymocyte globulin induction: use of integrated national registry data to achieve ten-year follow-up of 10-10 Study participants

Background

Rabbit antithymocyte globulin (rATG, Thymoglobulin®) is the most common induction immunosuppression therapy in kidney transplantation. We applied a database integration strategy to capture and compare long-term (10-year) outcome data for US participants in a clinical trial of rATG versus FDA-approved basiliximab.

Methods

Records for US participants in an international, 1-year, randomized clinical trial comparing rATG and basiliximab induction in deceased donor kidney transplantation were integrated with records from the US national Organ Procurement and Transplantation (OPTN) registry using center, transplant dates, recipient sex, and birthdates. The OPTN captures center-reported acute rejection, graft failure, death, and cancer events, and incorporates comprehensive death records from the Social Security Death Master File. Ten-year outcomes according to randomized induction regimen were compared by Kaplan–Meier analysis (two-sided P). Non-inferiority of rATG was assessed using a one-tailed equivalence test (a-priori equivalence margins of 0–10 %).

Results

Of 183 US trial participants, 89 % (n = 163) matched OPTN records exactly; the remainder were matched by extending agreement windows for transplant and birthdates. Matches were validated by donor and recipient blood types. By Kaplan–Meier analysis, 10 years post-transplant, freedom from acute rejection, graft failure, or death was 32.6 % and 24.0 % in the rATG and basiliximab arms, respectively (P = 0.09). The incidence of acute rejection with rATG versus basiliximab induction was 21.0 % versus 32.8 % (P = 0.07). Patient survival (52.5 % versus 52.2 %, P = 0.92) and graft survival (34.3 % versus 30.9 %, P = 0.56) rates were numerically and statistically similar for both arms. Comparison of the composite outcome meets non-inferiority criteria even with a 0 % equivalence margin (one-sided P = 0.04). With a 10 % equivalence margin, the odds that rATG is no worse than basiliximab for 10-year risk of the composite endpoint are >99 %.

Conclusions

Ten years post-transplant, rATG induction has comparable efficacy and safety to FDA-approved basiliximab. Integration of clinical trial records with national registry data can enable long-term monitoring of trial participants in transplantation, circumventing logistical and cost barriers of extended follow-up.

Trial registration

ClinicalTrials.gov NCT00235300

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0891-y) contains supplementary material, which is available to authorized users.

Conversion to sirolimus for chronic allograft nephropathy and calcineurin inhibitor toxicity and the adverse effects of sirolimus after conversion

BACKGROUND

Chronic allograft nephropathy and calcineurin inhibitor toxicity may cause graft loss. After kidney transplantation, especially among those patients with chronic allograft nephropathy, sirolimus may be a good alternative to calcineurin inhibitors. Unlike calcineurin inhibitors, sirolimus is devoid of significant nephrotoxicity, but approximately 30% to 50% of patients on sirolimus therapy display mild or severe adverse effects. We sought to report our experience with sirolimus conversion among patients with chronic allograft nephropathy as well as the mild versus severe adverse effects that limit the drug's use.

MATERIALS AND METHODS

We analyzed the outcomes of 88 patients (64 men and 24 women) of overall mean age of 35.9 +/- 9.9 years (range, 21-59 years) who had undergone kidney transplantation. Immunosuppressive therapy had been converted from a calcineurin inhibitor to sirolimus because of biopsy-proven chronic allograft nephropathy, calcineurin inhibitor toxicity, or presence of malignancy. We excluded patients with prior acute rejection episodes. Subjects were divided into two groups with respect to their creatinine levels: Group A < 2 mg/dL and Group B >or= 2 mg/dL. After conversion to sirolimus, possible adverse effects of sirolimus were evaluated at the follow-up inset. Each patient underwent a physical examination, and estimation of serum lipid and electrolyte levels as well as hemoglobin concentration.

RESULTS

At the time of conversion of the 88 renal transplant patients, their mean duration after grafting was 48 +/- 15 months (range, 4-296). The prior treatment consisted of a calcineurin inhibitor, prednisolone, and mycophenolate mofetil. After conversion, the calcineurin inhibitor was stopped and sirolimus was begun. The 48 Group 2 patients (34 men, 14 women) of overall mean posttransplant time of 22.7 +/- 14.6 months who underwent conversion displayed a mean serum creatinine increase to 3.2 +/- 1.4 mg/dL, including 17 subjects who underwent rejection. The 40 Group 1 patients (30 men, 10 women) with a mean overall posttransplant period of 67.6 +/- 49.9 months showed an fall in serum creatinine level to 1.4 +/- 0.5 mg/dL among only 3 patients. While 5/88 patients showed no increase in proteinuria (5.6%); 83 (94.4%) did experience it. Proteinuria increased from a mean of 192 +/- 316 to 449 +/- 422 mg/d. Only three patients displayed heavy proteinuria (>3 g/d); sirolimus was discontinued for this reason. Proteinuria was well controlled in the other patients with angiotensin-converting enzyme and/or angiotensin II receptor inhibitor agents. After sirolimus conversion, serum cholesterol levels increased from 187 +/- 42 to 214 +/- 52 mg/dL, and serum triglyceride levels increased from 161 +/- 61 to 194 +/- 102 mg/dL. All but four patients responded to statin therapy, with serum lipid levels falling to acceptable levels. Another four patients developed unilateral lower extremity edema with sirolimus discontinued for this reason. One patient displayed generalized arthralgia.

CONCLUSION

Chronic allograft nephropathy or calcineurin inhibitor toxicity can lead to loss of graft kidney function. Calcineurin inhibitor toxicity can lead to chronic allograft nephropathy. Patients with a low baseline serum creatinine level who undergo sirolimus conversion showed stabilized kidney function. Late conversion of patients with a serum creatinine above 2 mg/dL face a risk of graft failure. Sirolimus displayed a limited incidence of serious adverse effects; mild or moderate adverse effects, such as hyperlipidemia and proteinuria, were easily controlled with countermeasure therapy.

Chronic allograft dysfunction-is there a treatment?

BACKGROUND

The major causes of renal transplant loss are death and chronic allograft dysfunction (CAD). The aims of this study were to determine the incidence of CAD in our population and the relation between allograft survival and immunosuppressive regimens.

METHODS

We studied retrospectively 473 patients who received deceased donor kidney transplants with at least 1 allograft biopsy between January 1990 and May 2007. Clinical data included age, gender, biopsy data, and immunosuppression before and after kidney biopsy. Mean age was 45.4 +/- 12.7 years including 65% males with a mean follow-up of 6.7 +/- 4.5 years. CAD was observed in 177 of 473 biopsies: 48 patients showed interstitial fibrosis (IF); 101 chronic rejection (CR); 16 transplant glomerulopathy (TG); and 12, CR and TG. Mean follow-up since the discovery of the histologic feature was 60.5 +/- 50.5 months for IF; 38.3 +/- 40.8 for CR, and 18.2 +/- 19.2 for TG.

RESULTS

CAD, which was more common in younger patients (P = .03), correlated upon univariate and multivariate analysis with CKD stage 5d development (P < .001). Deposition of C4d in peritubular capillaries was more frequent among CAD patients (P = .004), an association with particular relevance to recipients with CR (P = .02) and TG (P < .001). When we analyzed CAD subpopulation, we observed a positive correlation between allograft survival and immunosuppression modification after biopsy. Substitution of sirolimus (40/177) was shown in univariate, multivariate and Cox regression analyses to be a renal protector (P < .002). Allograft survival was also correlated with initial mycophenolate mofetil versus azathioprine, (62/177) immunosuppression (P < .001).

CONCLUSION

CAD, a frequent histologic feature, may benefit from sirolimus conversion.

Gingival status of Brazilian renal transplant recipients under sirolimus-based regimens

BACKGROUND

Although the prevalence of gingival overgrowth (GO) in calcineurin-inhibitor (CNI) immunosuppressive regimens has been well documented, to the best of our knowledge data from sirolimus (SIR) regimens have not been described. We sought to investigate the gingival status of renal transplant recipients under SIR-based regimens with regard to the prevalence and potential risk variables associated with GO.

METHODS

A cross-sectional study was conducted at a public hospital in Belo Horizonte, MG, Brazil. Of 886 transplant recipients, an eligible sample of 144 subjects was selected. Medical, pharmacologic, and periodontal variables were recorded for each subject. GO was assessed through visual inspection and was evaluated in relation to variables of interest by univariate and multivariate analyses.

RESULTS

Although not clinically significant, 20.8% of the samples had GO, with a mean GO score of 5.0% +/- 3.98% (range, 0% to 19%) and mean GO score per papilla of 0.378 +/- 0.361 (range, 0.1 to 1.9); the percentage of papilla affected by GO was 14.35% +/- 9.86% (range, 5% to 45%). The multivariate final model, excluding periodontal variables, showed that the concomitant use of calcium channel blockers (P = 0.033) and the interaction between time since transplant and previous CNI use (P <0.001) were associated with GO. Adding periodontal variables to the model improved its accuracy and retained papillary bleeding index as being strongly associated with GO (P <0.001).

CONCLUSIONS

GO was observed in a considerable number of subjects under SIR-based immunosuppressive regimens, although the relationship was not clinically significant. Findings point to the importance of cooperation between medical and dental health care personnel in the maintenance of renal transplant recipients under SIR-based immunosuppressive regimens.

Aging, stem cells, and mammalian target of rapamycin: a prospect of pharmacologic rejuvenation of aging stem cells

What is the relationship between stem cell aging and organismal aging? Does stem cell aging cause organismal aging or vice versa? Will stem cell aging aggravate age-related diseases? And what is stem cell aging? As suggested herein, hyperstimulation of signal transduction pathways can render cells compensatorily irresponsive. And the hallmark of stem cell aging is poor responsiveness to activating stimuli. On the basis of the hypothesis that insensitivity to stimuli is in part due to hyperactivation of the target of rapamycin (TOR), this article suggests a means of pharmacologic rejuvenation of stem cells and wound-healing cells.