Risk factors affecting the long-term results of renal retransplantation

[Renal retransplantation: risk factors and results]

OBJECTIVE

to review our experience in renal retransplantations.

MATERIALS AND METHODS

we carried out a retrospective study on 71 patients with retransplantation performed between 1980 and 2005. We studied: the characteristics of the recipient and graft, surgery data, causes of loss of the graft, number of rejects and transplantectomies and, survival of the graft.

RESULTS

the most frequent cause of graft loss was chronic rejection. The causes of first graft loss were not associated with a greater loss of the second graft (p>0.05). The percentage of anti-HLA antibodies increased in the second transplant in comparison to the first (17.23±27.91% vs. 1.21±7.43%) (p=0.001), however, it was not correlated with a significant increase in loss of the second graft (p=0.320). There were no significant differences between the complications of the first and second transplants (p>0.05) and they were not associated with graft loss (p>0.05). The patients with a transplantectomy in the first transplant presented a risk 8.5 times higher of undergoing a second one (p=0.0001; OR: 8.54; CI: 95% 0.941 - 77.501). The most frequent cause of transplantectomies in the second transplant was acute rejection. Acute rejection as a cause for transplantectomy in the first transplant proved to be an independent risk factor of transplantectomy of the second transplant (p=0.009). The mean survival of the second graft was 5.08±4.81 years, higher than the first transplant (p=0.133). The survival of the graft at 1.5 and 10 years was 83%, 75% and 52%, respectively.

CONCLUSIONS

the survival of the second transplant was not lower than the first, neither was there an increase in the number of complications.

Acute rejection and chronic nephropathy: a systematic review of the literature

BACKGROUND

The risk of graft failure is the pivotal measure of effectiveness when evaluating immunosuppressive regimens for renal transplantation. However, to date most randomized trials of immunosuppressive therapy have had acute rejection as the primary endpoint for treatment comparisons. The objective here was to review the evidence relating acute rejection to renal graft function and graft survival.

METHODS

A systematic review of the published literature was undertaken. Studies were reviewed if they included the following: study populations of adults undergoing renal transplantation, endpoints of graft loss or survival, and quantitative data on the associations between acute rejection and graft function and survival.

RESULTS

Overall, 31 observational studies were included. The definition of acute rejection varied, and there was substantial heterogeneity in study design and methodology. In all but two studies, acute rejection was associated with an increased risk of graft loss-risk ratios ranged from 1.2 (no definition reported) to 10.5 (confirmed by biopsy and grade I Banff criteria). In addition, there was fairly strong evidence linking timing of acute rejection and graft survival and weaker evidence linking the number of episodes and graft survival. The heterogeneity between studies invalidated pooling of quantitative studies.

CONCLUSIONS

The weight of the evidence indicates that occurrence, timing, and number of acute rejection episodes are associated with increased risk of graft loss. Less is known about the severity of rejection, which is important because many immunosuppressive regimens lessen severity. Quantifying these relationships is a priority if acute rejection continues to be a surrogate trial endpoint.

Mortality experience in recipients undergoing repeat transplantation with expanded criteria donor and non-ECD deceased-donor kidneys

Nearly one-quarter of the kidney transplant waiting list is composed of repeat transplantation candidates. Survival following retransplantation using expanded criteria donor (ECD) kidneys has not been adequately studied. Using data from the Scientific Registry of Transplant Recipients, we analyzed mortality after retransplantation with ECD and non-ECD deceased-donor kidneys. Adult patients who experienced graft failure and were relisted for transplantation between 1995 and 2004 were studied (n=9641). Follow-up began at the date of relisting and continued until death or the end of the observation period (December 31, 2004), with censoring at living-donor transplantation. Sequential stratification (an extension of Cox regression) was used to compare mortality between patients receiving an ECD retransplant and those remaining on the waiting list or receiving a non-ECD retransplant (conventional therapy). Of 2908 retransplantations, 292 used ECD kidneys. Survival after ECD retransplantation was approximately equal to that of conventional therapy, with an adjusted hazard ratio of 0.98 (p=0.88). In contrast, non-ECD retransplant recipients experienced a significant reduction in mortality (HR=0.44; p<0.0001). Based on these national data, recipients of ECD retransplantation do not have a survival advantage relative to conventional therapy, whereas non-ECD retransplantation is associated with a significant survival advantage.

Second and Third Kidney Transplantations

We reviewed the results of second and third kidney transplantations at our center. Among 1500 patients who had undergone kidney transplantation from 1968 to October 2005, we discovered 77 (male 55 and female 22 of overall mean age = 48.9 years) second transplantations and 5 (male 4, female 1; mean age = 46.8 years) third transplantations. The 82 kidneys were derived from living donors in 67 patients and from cadaveric donors in 15 patients. The mean duration from the first to the second transplantation was 89 months, and from the second to the third transplantation, 32.7 months. Among the second and third transplantations and graft nephrectomies, we failed to observe additional surgical complications compared with first transplants and over 80% graft survival at 1 year.

The effect of graft nephrectomy on long-term graft function and survival in kidney retransplantation

We retrospectively evaluated the long-term results of 53 (3.5%) recipients who received second allograft among 1486 kidney transplants between November 3, 1975 and June 30, 2004. Two study groups were patients in Group 1 (n = 21) who underwent allograft nephrectomy and those in Group 2 (n = 32) who did not. We assessed demographic features, rejection rates throughout the follow-up period, and serum creatinine levels at 12 months as well as graft and patient survival rates, postoperative complications, time interval between transplantations, and HLA matches. Forty-three patients who underwent retransplantation received kidneys from living-related donors and the remaining 10 from cadaveric donors. Mean serum creatinine levels of Group 1 versus Group 2 were 1.8 mg/dL (range, 0.8 to 6.6 mg/dL) versus 2.1 +/- 1.1 mg/dL (range, 1.1 to 7.1 mg/dL). HLA-AB and HLA-DR mismatches were 1.9 +/- 1.1 versus 1 +/- 0.6, respectively (P = .01). Acute rejection rates were not significantly different between Groups 1 (9/21, 43%) and 2 (12/32, 38%) (P < .05). The average intervals between the first and the second transplantations were 62 +/- 26 months in Group 1 (P = .02) and 32 +/- 11 months in Group 2. One-, 3-, and 5-year graft survival rates in Group 1 versus Group 2 were 83% versus 89% (P > .05); 64% versus 79% (P > .05), and 45% versus 68% (P = .04), respectively. In conclusion, we did not observe any advantage of graft nephrectomy before retransplantation. The length of the interval between the first and the second transplantations may have a negative correlation with second graft survival.

Living-donor kidney retransplantation: risk factors and outcome

OBJECTIVE

To review the results of kidney retransplantation at our centre.

PATIENTS AND METHODS

Between March 1976 and January 2002, 1406 kidneys were transplanted; among these, 54 patients received a second graft (39 men, mean age 32.1 years, sd 8.6). The donors were 48 relatives (mean age 35.4 years, sd 10.1).

RESULTS

The mean (sd, range) duration of the first graft was 49.1 (45.9, 1-192) months and the main cause of these grafts failing was immunological. The mean duration of graft failure was 17.3 (10.5, 5-62) months. The rate of histocompatibility leukocyte antigen (HLA)-A, -B >3 was 16.7% and of haplotype DR matching was 11%. The immunosuppression regimen was mainly based on cyclosporin (75%). There were 33 episodes of acute rejection in 23 patients. The major complications were hypertension (70%), infections (30%) and hepatitis (11%). The overall graft and patient survival was good; 15 grafts (27%) were lost during the follow-up of 1-17 years. Ten patients died, five with a functioning graft. Multivariate analysis showed that donor relationship, primary immunosuppression, duration of first graft and serum creatinine level at 1 year were predictors of graft survival.

CONCLUSION

Renal retransplantation is the treatment of choice in patients who have lost their graft. The use of related living-donors and potent immunosuppression could help to improve the outcome.