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Recipient Body Weight Mismatch on Allograft Outcome in Renal Transplant Recipients
Impact of Donor/Recipient Body Weight Mismatch on Allograft Outcome in Renal Transplant Recipients A. Ghafari, J. Etemadi, and M. Ardalan ABSTRACT Background. There have been conflicting reports that kidneys from small donors may be at risk for graft loss if they are transplanted into large recipients. The aim of this work was to examine the impact of donor/recipient body weight ratio (D/RBWR) on allograft outcome. Patients and Methods. Two hundred and seventeen kidney transplant recipients from living unrelated donor with 5-year follow-up underwent immunosuppression with cyclosporine, mycophenolate mofetil (or azathioprine), and prednisolone. According to the D/RBWR, the patients were divided into 3 groups: low (less than 0.8; G1), medium (0.81–1.1; G2), and high (more than 1.1; G3). We recorded 1-, 3-, and 5-year graft survivals, episodes of acute rejection, and mean serum creatinine values. Results. Among the patients, 126 (58%) were female and the overall mean age was 41.62 years. There were no significant differences in 1-, 3-, and 5-year allograft survivals between the groups. Conclusion. We concluded that low D/RBWR had no effect on short- or long-term renal allograft survival.
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ONG-TERM ALLOGRAFT LOSS is determined by a number of factors. In recent years there has been increasing attention on nonimmunologic factors.1 An increased glomerular capillary pressure, flow, and filtration (ie, hyperfiltration) have been associated with progressive kidney injury.2– 4 If the hyperfiltration theory applies to transplantation in humans, it would be expected to result in decreased allograft survival. Limited observations have suggested that lower donor nephron mass is associated with poorer graft outcome: namely, female to male transplantations, pediatric kidneys transplanted into adults, and elderly donors.5–7 Kidney weight and body weight correlate directly with outcomes.6 –9 Thus, the donor/recipient body weight ratio (D/RBWR) has been considered when matching donors and recipients. In this study, we retrospectively investigated the impact of D/RBWR on short- and longterm outcomes of living donor kidney transplantations. PATIENTS AND METHODS This retrospective study of renal transplant patients at our transplant center from April 1999 until April 2002 included 5-year follow-up; 1-, 3-, and 5-year graft survivals, episodes of acute rejection and serum creatinine levels were recorded from patient’s documents. We considered the recipient’s body weight and the © 2008 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 40, 135–136 (2008)
donor’s body weight at the time of transplantation. The donors and recipients based on D/RBWR were divided into 3 groups: low ratio (less than 0.8; G1), medium ratio (0.81–1.1;G2), and high ratio (more than 1.1;G3). Graft survival defined as return to dialysis was analyzed by Kaplan-Meier curves. The results were compared by statistical methods using SPSS for Windows version 11 (SPSS Inc, Chicago, Ill, United States).
RESULTS
Among 232 renal allograft recipient and donor pairs, 15 cases were excluded because of follow-up failure. The remaining 217 recipients included 126 (58%) females and 91 (42%) males. The mean age of these patients was 41.62 ⫾ 6.1 years. The mean value of recipient weight was 53 ⫾ 5.8 kg and the mean value of donor weight was 58 ⫾ 9.6 kg. According to D/RBWR categorization 52 pairs (24%) were From the Department of Nephrology (A.G.), Urmia University of Medical Sciences, Urmia, Iran and the Department of Nephrology (J.E., M.A.), Tabriz University of Medical Sciences, Tabriz, Iran. Address reprint requests to Ali Ghafari, MD, Department of Nephrology, Urmia University of Medical Sciences, Urmia, Iran. E-mail: [email protected] 0041-1345/08/$–see front matter doi:10.1016/j.transproceed.2007.11.029 135
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GHAFARI, ETEMADI, AND ARDALAN
Table 1. Allograft Survival Rates Among Different Groups Donor/Recipient Body Weight Ratio
1-y graft survival (%) 3-y graft survival (%) 5-y graft survival (%)
G1
G2
G3
P
92.62 81.21 69.46
91.41 80.34 66.93
90.22 79.23 70.17
.74 .88 .73
in G1; 130 pairs (60%) in G2; and 34 pairs (16%) in G3. One-, 3-, and 5-year graft survivals in each group are shown in Table 1, demonstrating no significant differences. DISCUSSION
We concluded that low D/RBWR had no effect on short- or long-term allograft survival, although other observations suggest that lower donor nephron mass is associated with poorer graft outcome, including female to male transplantation, pediatric kidneys transplanted into adults, and elderly donors.5–7 The weight ranges of our recipients and donors were close. All of our kidney transplantations were from living donors, which may be the reason why we did not observe an impact of weight on renal transplantation outcomes. Although we need greater numbers of patients and longer-term follow-up, our results do not confirm the
original hypothesis of compensatory changes in glomerular capillary pressures leading directly or indirectly to progressive kidney damage.2,3,7
REFERENCES 1. Bio MJ: Nonimmunologic causes of late renal graft loss. Kidney Int 47:49, 1995 2. Chanutin A, Ferris EB: Experimental renal insufficiency produced by partial nephrectomy. Arch Intern Med 49:767, 1932 3. Morrison AB: Experimentally induced chronic renal insufficiency in the rat. Lab Invest 11:332, 1962 4. Hostetter TH, Olson JL, Rennke HG, et al: Hyperfiltration in remnant nephrons: a potentially adverse response to renal ablation. Am J Physiol 241:F85, 1981 5. Texasaki PI, Gjertson DW, Cecka JM, et al: Fit and match hypothesis for kidney transplantation. Transplantation 62:441, 1996 6. Neugarten J, Srinivas T, Tellis V, et al: The effect of donor gender on renal allograft survival. J Am Soc Nephrol 7:318, 1996 7. Moreso S, Seron D, Anunciada AI, et al: Recipient body surface area as a predictor of post-transplant renal allograft evaluation. Transplantation 65:671, 1998 8. EL-Agroudy AE, Hassan NA, Bakr MA: Effect of donor/ recipient body weight mismatch on patients and graft outcome in living-donor kidney transplantation. Am J Nephrol 23:294, 2003 9. Andrews PA, Compton F, Koffman CG: Influence of donor/ recipient size in living donor kidney transplantation. Transplant Proc 33:1146, 2001
L
ONG-TERM ALLOGRAFT LOSS is determined by a number of factors. In recent years there has been increasing attention on nonimmunologic factors.1 An increased glomerular capillary pressure, flow, and filtration (ie, hyperfiltration) have been associated with progressive kidney injury.2– 4 If the hyperfiltration theory applies to transplantation in humans, it would be expected to result in decreased allograft survival. Limited observations have suggested that lower donor nephron mass is associated with poorer graft outcome: namely, female to male transplantations, pediatric kidneys transplanted into adults, and elderly donors.5–7 Kidney weight and body weight correlate directly with outcomes.6 –9 Thus, the donor/recipient body weight ratio (D/RBWR) has been considered when matching donors and recipients. In this study, we retrospectively investigated the impact of D/RBWR on short- and longterm outcomes of living donor kidney transplantations. PATIENTS AND METHODS This retrospective study of renal transplant patients at our transplant center from April 1999 until April 2002 included 5-year follow-up; 1-, 3-, and 5-year graft survivals, episodes of acute rejection and serum creatinine levels were recorded from patient’s documents. We considered the recipient’s body weight and the © 2008 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 40, 135–136 (2008)
donor’s body weight at the time of transplantation. The donors and recipients based on D/RBWR were divided into 3 groups: low ratio (less than 0.8; G1), medium ratio (0.81–1.1;G2), and high ratio (more than 1.1;G3). Graft survival defined as return to dialysis was analyzed by Kaplan-Meier curves. The results were compared by statistical methods using SPSS for Windows version 11 (SPSS Inc, Chicago, Ill, United States).
RESULTS
Among 232 renal allograft recipient and donor pairs, 15 cases were excluded because of follow-up failure. The remaining 217 recipients included 126 (58%) females and 91 (42%) males. The mean age of these patients was 41.62 ⫾ 6.1 years. The mean value of recipient weight was 53 ⫾ 5.8 kg and the mean value of donor weight was 58 ⫾ 9.6 kg. According to D/RBWR categorization 52 pairs (24%) were From the Department of Nephrology (A.G.), Urmia University of Medical Sciences, Urmia, Iran and the Department of Nephrology (J.E., M.A.), Tabriz University of Medical Sciences, Tabriz, Iran. Address reprint requests to Ali Ghafari, MD, Department of Nephrology, Urmia University of Medical Sciences, Urmia, Iran. E-mail: [email protected] 0041-1345/08/$–see front matter doi:10.1016/j.transproceed.2007.11.029 135
136
GHAFARI, ETEMADI, AND ARDALAN
Table 1. Allograft Survival Rates Among Different Groups Donor/Recipient Body Weight Ratio
1-y graft survival (%) 3-y graft survival (%) 5-y graft survival (%)
G1
G2
G3
P
92.62 81.21 69.46
91.41 80.34 66.93
90.22 79.23 70.17
.74 .88 .73
in G1; 130 pairs (60%) in G2; and 34 pairs (16%) in G3. One-, 3-, and 5-year graft survivals in each group are shown in Table 1, demonstrating no significant differences. DISCUSSION
We concluded that low D/RBWR had no effect on short- or long-term allograft survival, although other observations suggest that lower donor nephron mass is associated with poorer graft outcome, including female to male transplantation, pediatric kidneys transplanted into adults, and elderly donors.5–7 The weight ranges of our recipients and donors were close. All of our kidney transplantations were from living donors, which may be the reason why we did not observe an impact of weight on renal transplantation outcomes. Although we need greater numbers of patients and longer-term follow-up, our results do not confirm the
original hypothesis of compensatory changes in glomerular capillary pressures leading directly or indirectly to progressive kidney damage.2,3,7
REFERENCES 1. Bio MJ: Nonimmunologic causes of late renal graft loss. Kidney Int 47:49, 1995 2. Chanutin A, Ferris EB: Experimental renal insufficiency produced by partial nephrectomy. Arch Intern Med 49:767, 1932 3. Morrison AB: Experimentally induced chronic renal insufficiency in the rat. Lab Invest 11:332, 1962 4. Hostetter TH, Olson JL, Rennke HG, et al: Hyperfiltration in remnant nephrons: a potentially adverse response to renal ablation. Am J Physiol 241:F85, 1981 5. Texasaki PI, Gjertson DW, Cecka JM, et al: Fit and match hypothesis for kidney transplantation. Transplantation 62:441, 1996 6. Neugarten J, Srinivas T, Tellis V, et al: The effect of donor gender on renal allograft survival. J Am Soc Nephrol 7:318, 1996 7. Moreso S, Seron D, Anunciada AI, et al: Recipient body surface area as a predictor of post-transplant renal allograft evaluation. Transplantation 65:671, 1998 8. EL-Agroudy AE, Hassan NA, Bakr MA: Effect of donor/ recipient body weight mismatch on patients and graft outcome in living-donor kidney transplantation. Am J Nephrol 23:294, 2003 9. Andrews PA, Compton F, Koffman CG: Influence of donor/ recipient size in living donor kidney transplantation. Transplant Proc 33:1146, 2001