Activated circulating dendritic cells after hematopoietic stem cell transplantation predict acute graft-versus-host disease

BACKGROUND

Dendritic cells (DC) are central to the development of acute graft-versus-host disease (GVHD) following allogeneic hematopoietic stem cell transplantation (alloHSCT). We hypothesized that DC activation status determines the severity of GVHD and that activated DC may be detected in the circulation prior to clinical presentation of GVHD.

METHODS

Following transplant, blood samples were obtained twice weekly from alloHSCT patients. Myeloid (CD11c+) and plasmacytoid (CD123hi) DC were enumerated by flow cytometry, and activated myeloid DC were identified using the CMRF-44 monoclonal antibody.

RESULTS

Of 40 alloHSCT patients, 26 developed acute GVHD. Severity of GVHD was associated with low total blood DC counts (P=0.007) and with low myeloid and plasmacytoid DC numbers (P=0.015 and 0.003). The CMRF-44 antigen was expressed on blood CD11c+ DC in all cases prior to GVHD onset, whereas of the 14 patients without GVHD, seven had no CMRF-44+ CD11c DC. Patients with CMRF-44+ CD11c+ DC in more than 20% of samples were more likely to subsequently develop acute GVHD (P=0.001, odds ratio=37.1), while patients who developed grade 2-4 GVHD had prior higher percentages of CMRF-44+ CD11c+ DC compared to grade 0-1 GVHD patients (P=0.001). CMRF-44 expression on >7.9% CD11c+ DC predicted for subsequent development of GVHD with a sensitivity of 87.5% and specificity of 79.2%.

CONCLUSIONS

Activation status, as assessed by CMRF-44 antigen expression, of blood CD11c+ DC is highly associated with acute GVHD and these cells may be targets for therapeutic intervention.

Donor safety in adult living donor liver transplantation using the right lobe: Single center experience in China

AIM: To evaluate the safety of donors in adult living donor liver transplantation (LDLT) using the right lobe in a single liver transplantation center in China.

METHODS: We investigated retrospectively 52 living donor liver resections performed from October 2003 to July 2006. All patients were evaluated by blood tests and abdominal CT. The mean donor age was 28.2 ± 7.4 years. Residual liver volume was 42.1% ± 4.7%. Mean operative time was 420 ± 76.2 min; mean ICU stay, less than 36 h; mean hospital stay, 16.4 ± 8.6 d; and mean follow-up period, 6 mo.

RESULTS: There was no mortality. The overall complication rate was 40% (21 donors). Major complications included biliary leak in two, and pneumonia in 2 donors. Minor complications included mild pleural effusion in 12 donors, transient ascites in 6, mild depression in 4, intra-abdominal collections in 2, and wound infections in 1 donor. Residual liver volume did not affect the complication rate. None required re-operation. Return to pre-donation activity occurred within 5-8 wk.

CONCLUSION: Right hemi-hepatectomy can be performed safely with minimal risk in cases of careful donor selection. Major complications occurred in only 7.7% of our series.

Graft selection algorithm based on congestion volume for adult living donor liver transplantation

A major concern in adult-to-adult living donor liver transplantation is the selection of graft type; that is, is it is better to use the right lobe with or without the middle hepatic vein (MHV)? This choice has a considerable impact on donor safety, vascular reconstruction and graft function in the recipient. To facilitate making an appropriate choice, on the basis of a preliminary study (n = 17), we herein propose a graft selection algorithm using three parameters: graft-to-recipient body weight ratio (GRWR), percentage remnant liver volume (%RLV) and estimated congestion ratio (ECR). The algorithm was evaluated with 50 consecutive cases with respect to postoperative liver function of donors and recipients and survival of recipients. Postoperative recovery was comparable between the two groups (p = NS). The overall cumulative 18-month survival rate was 86.7% for the 'with MHV graft group', and 76.1% for the gwithout MHV graft grouph (p = NS). For 41 cases (82%), graft types were chosen according to the algorithm, whereas the remaining 9 cases (18%) needed detailed discussion of donor, recipient and operative factors. In conclusion, we constructed a graft selection algorithm based on congestion volume, which will contribute to objective graft-type selection in adult-to-adult LDLT.

Patient and allograft survival of Indo Asian and East Asian dialysis patients treated in Canada

Kidney failure is relatively common among Canadians of Asian origin. However, little is known about the health outcomes after initiation of renal replacement therapy in this population. Our study evaluates differences in the likelihood of renal transplantation and graft loss among Asian and white patients. We studied 21 523 adults of East Asian, Indo Asian or white ethnicity who had initiated dialysis in Canada from 1990-2000. Subjects were followed until death, loss to follow-up or end of study (2004). The proportion of the eligible subjects who were East Asian, Indo Asian, or white was 6, 3, and 91%, respectively. Compared to white patients, East Asian and Indo Asian patients were significantly less likely to receive a renal transplant after adjusting for potential confounding factors. This disparity is greater for transplants from living donors as compared to those from deceased donors. The adjusted death censored graft loss in transplant recipients was not significantly different between ethnic groups. The adjusted risk of death following transplantation, however, was significantly lower in Indo Asian than in white patients. Our findings show that in a Canadian population, patients of East Asian or Indo Asian origin had lower rates of renal transplantation than white patients, especially for living donor transplantation. These findings warrant further study, especially given the good graft outcomes in these individuals.

Five Years of Single-Center Experience With Paired Kidney Exchange Transplantation

INTRODUCTION

Due to the organ shortage, living donor transplantation has become a method to bridge the gap. Paired kidney exchange program (PKEP) is a viable method especially when there are incompatible related living donors. Even if there are still some unanswered questions, this program is current in some centers, and there appears to be a tendency to extend it in Europe. The aim of our study was to assess our results with PKEP after 5 years.

METHODS

Between January 2001 and December 2005, we performed 56 living donor kidney transplantations using this method. We performed 26 kidney exchange procedures: 23 with two pairs, two with three pairs, and one with four pairs. Extensive preoperative work was necessarily to obtain equivalent pairs from the anatomic, functional, and immunological points of view. The same team performed all transplants. The mean recipient age was 35.59 years (range 29 to 44). Mean waiting time for a renal transplant was 33.27 months (range 11 to 87).

RESULTS

At a median follow-up of 41 months (range 7 to 59), the rates of acute rejection and graft survival-19.64% and 98.21%-were similar to direct living donation-14.66% and 97.92%, respectively (P = .35 and .88, respectively).

CONCLUSION

The paired kidney exchange program is a viable procedure medically and economically, which can be promoted in centers with a low deceased donor transplantation rate and a high number of incompatible related donors.

Three-quarters of right liver donors experienced postoperative complications

A donor right hepatectomy (RH) is associated with a higher rate of morbidity than a left hepatectomy. Therefore, the precise morbidity should be known to improve the success of donor RH implementation. However, the rate of complication varies according to the individual definition of morbidity. This study prospectively analyzed the outcomes of 83 consecutive living donor RHs between January 2002 and July 2004 using a standardized classification of the severity of complications. The morbidity was classified using the modified Clavien system: grade I for minor complications; grade II for potentially life-threatening complications requiring pharmacological treatment; grade III for complications requiring invasive intervention; grade IV for complications causing organ dysfunction requiring intensive care unit management; and grade V complications resulting in the death of the patient. The donors were followed-up regularly for at least 12 months. No donor death or relaparotomy was noted. Overall, 65 out of 83 donors (78.3%) experienced postoperative complications: grades I, II, III, IV, and V complications in 64 (77.1%), 11 (13.3%), 1 (1.2%), 0, and 0 patients, respectively. The most common grade I complications were hyperbilirubinemia (n = 31) and pleural effusion (n = 31), and bile leakage in grade II (n = 7). The bilirubin and alanine aminotransferase levels were normal in 92.7% of donors at the 1-year follow-up. In conclusion, although most of these adverse events were minor and self-limited, 78% of right liver donors still experienced morbidity. Therefore, continuous standardized reporting of the donor morbidity as well as meticulous surgery and intensive care are essential for the success of donor RH implementation.

Whole-liver graft without the retrohepatic inferior vena cava for sequential (domino) living donor liver transplantation

Grafts used in Domino liver transplantation (LT) obtained from living donor liver transplantation (LDLT) for familial amyloid polyneuropathy (FAP) patients have been mainly used as reduced grafts. Because of small-for-size problems seen in LDLT, using whole liver grafts could improve post-LT outcome. Eight consecutive Domino LDLT using whole livers without retrohepatic inferior vena cava (IVC) from FAP patients were retrospectively analyzed. The graft weight/recipient's body weight ratio (GWRW) in the domino recipients ranged from 1.28% to 2.4% (mean: 1.52). Multiple vascular reconstructions in the whole-liver domino LT resulted in longer than usual warm ischemia time (mean: 64 min); however immediate post-operative recovery of hepatic function was uneventful. At 8-40 months after the transplant, all the FAP patients are well and all of the domino recipients are alive. Domino LT using a whole FAP liver from a LDLT for a FAP patient presents satisfactory results, even though the transplant procedure is technically complicated.

Effect of population aging on the international organ donation rates and the effectiveness of the donation process

This study analyzed the effect of population aging on organ donation for transplants in 43 countries and on the effectiveness of the donation process by comparing the results between Spain and the United States. The percentage of the population aged 65 or over accounted for 33% of the difference in the donation rates between the countries and for 91% of the variation in the rates after age adjustment. However, the level of aging of the Spanish (16.5%) and American (12.3%) populations failed to account for the percentages of deceased donors 65 or over (28% vs. 10%), due to the different age-specific donation rates, much higher in Spain above 50 years. These differences lead to a higher effectiveness of the process in the United States (3.1 transplanted organs per donor vs. 2.5 in Spain), though at lower rates of transplant per million population (73 vs. 87). We conclude that older populations have a greater donation potential as donation rates are strongly associated with population aging. It should therefore be mandatory to adjust donation rates for age before making comparisons. Additionally, effectiveness decreases with older donors, so age should be considered when establishing standards relating to organ donation and effectiveness of the process.

Hepatocellular carcinoma recurrence and death following living and deceased donor liver transplantation

We examined mortality and recurrence of hepatocellular carcinoma (HCC) among 106 transplant candidates with cirrhosis and HCC who had a potential living donor evaluated between January 1998 and February 2003 at the nine centers participating in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Cox regression models were fitted to compare time from donor evaluation and time from transplant to death or HCC recurrence between 58 living donor liver transplant (LDLT) and 34 deceased donor liver transplant (DDLT) recipients. Mean age and calculated Model for End-Stage Liver Disease (MELD) scores at transplant were similar between LDLT and DDLT recipients (age: 55 vs. 52 years, p = 0.21; MELD: 13 vs. 15, p = 0.08). Relative to DDLT recipients, LDLT recipients had a shorter time from listing to transplant (mean 160 vs. 469 days, p < 0.0001) and a higher rate of HCC recurrence within 3 years than DDLT recipients (29% vs. 0%, p = 0.002), but there was no difference in mortality or the combined outcome of mortality or recurrence. LDLT recipients had lower relative mortality risk than patients who did not undergo LDLT after the center had more experience (p = 0.03). Enthusiasm for LDLT as HCC treatment is dampened by higher HCC recurrence compared to DDLT.

Donor Gender Balance in a Living-Related Kidney Transplantation Program in Oman

It has been observed in several Eastern and Western countries that there is a gender imbalance among kidney donors. In the international experience, approximately 65% of live kidney donors have been women. We retrospectively studied the distribution of female and male donors or recipients among living kidney transplantations performed from 1980 to 2005, namely 198 Omani recipients of living-related kidney transplantations. To examine cultural influences, transplantations performed or expatriates were excluded from the study. For the whole period, 98 out of 198 donors (49.5%) were women. The number of female recipients 75 of 198 (38%) versus males were 123 (62%) recipients. We then subdivided the period into three intervals: 1980 to 1990, 1991 to 2000, and 2001 to 2005. The numbers of female donors for these three periods were 29 of 64 (45%), 42 of 89 (47%), and 27 of 45 (60%), respectively. There was a persistent preponderance of male recipients ranging from 58% to 66% during these periods. We concluded that there was no gender imbalance for kidney donors. Nevertheless, there was a male preponderance in the recipient group.

Organ donation and utilization in the United States, 1996-2005

The success of clinical transplantation as a therapy for end-stage organ failure is limited by the availability of suitable organs for transplant. This article discusses continued efforts by the transplant community to collaboratively improve the organ supply. There were 7593 deceased organ donors in 2005. This represents an all-time high and a 6% increase over 2004. Increases were noted in deceased organ donation of all types of organs; notable is the increase in lung donation, which occurred in 17% of all deceased donors. The percentage of deceased donations that occurred following cardiac death has also reached a new high at 7%. The number of living donors decreased by 2%, from 7003 in 2004 to 6895 in 2005. This article discusses the continued efforts of the Organ Donation Breakthrough Collaborative and the Organ Transplantation Breakthrough Collaborative to support organ recovery and use and to encourage the expectation that for every deceased donor, all organs will be placed and transplanted.

Kuwait Experience in Laparoscopic Donor Nephrectomy: First 80 Cases

INTRODUCTION

Laparoscopic donor nephrectomy (LDN) has been adopted rapidly as it offers less postoperative pain, early recovery, and better cosmetic results compared with the open approach. This prospective study investigated the results of the first 80 LDN performed between May 2005 and May 2006, with regard to donor morbidity and effect on graft function.

PATIENTS AND METHODS

LDN was attempted in 80 donors by one surgical team. Donors included 68 men and 12 women, ages 22 to 53 years, with body mass indices of 17.9 to 42.4. According to computed tomographic angiography, left nephrectomy was planned in 75 donors and right nephrectomy in 5.

RESULTS

LDN was completed successfully in 74 (92.5%) and converted to open in 6 (7.5%) secondary to technical difficulties and operative bleeding. The mean operating time for LDN was 186.16 minutes (range, 95-260 minutes). Mean warm ischemia time (WIT) was 5.7 minutes (range 2-16 minutes). Mean hospital stay was 5.28 days (range, 3-14 days). Two donors (2.5%) were reexplored for postoperative bleeding. Renal function in all donors was satisfactory within 3 months of surgery. Immediate diuresis occurred in 76 (95%) recipients. Acute cellular rejection was diagnosed in 1 recipient. No association was observed between WIT, graft function, development of acute tubular necrosis (ATN), or rejection. Plasma creatinine normalization was clearly associated with donor age.

CONCLUSIONS

LDN was found to be a safe procedure with low postoperative morbidity and short recovery time for donors. It can potentially increase the donor pool.

[Allo- and xeno-transplantation]

Organ transplantation is now effective therapies across a wide range of both fatal and non-fatal diseases. The excellent survival and success rates of organ transplantation have led to high levels of demand globally. The demand has outstripped the supply of organs from both deceased donors and from the altruistic living relatives of patients in need. Increasing use, over the past 10 years, of living donation of nonregenerative organs has extended from kidneys to livers, lungs and pancreas in some instances, despite the hope that reliance on living donors could be reduced. And, it is clear that ethically-unacceptable practices occur in a number of countries. The 1991 World Health Organization (WHO) Guiding Principles (GP) have influenced national legislation and professional codes but over the last 10 years many transplantation practices are no longer in line with the GP. The GP will be revised in 2008. While xenotransplantation offers a potential solution to the demand, 3 problems need to be overcome, i.e. inadequate physiological function, rejection of the graft, and the risk of transmitting a serious and/or novel infectious disease to the human recipient and wider public.

Geographic variability in access to primary kidney transplantation in the United States, 1996-2005

This article focuses on geographic variability in patient access to kidney transplantation in the United States. It examines geographic differences and trends in access rates to kidney transplantation, in the component rates of wait-listing, and of living and deceased donor transplantation. Using data from Centers for Medicare and Medicaid Services and the Organ Procurement and Transplantation Network/Scientific Registry of Transplant Recipients, we studied 700,000+ patients under 75, who began chronic dialysis treatment, received their first living donor kidney transplant, or were placed on the waiting list pre-emptively. Relative rates of wait-listing and transplantation by State were calculated using Cox regression models, adjusted for patient demographics. There were geographic differences in access to the kidney waiting list and to a kidney transplant. Adjusted wait-list rates ranged from 37% lower to 64% higher than the national average. The living donor rate ranged from 57% lower to 166% higher, while the deceased donor transplant rate ranged from 60% lower to 150% higher than the national average. In general, States with higher wait-listing rates tended to have lower transplantation rates and States with lower wait-listing rates had higher transplant rates. Six States demonstrated both high wait-listing and deceased donor transplantation rates while six others, plus D.C. and Puerto Rico, were below the national average for both parameters.

Donor factors influencing graft outcomes in live donor kidney transplantation

Living donor renal allograft survival is superior to that achieved from deceased donors, although graft outcome is suboptimal in some of these patients. In an effort to identify the subset of patients at high risk for poor outcomes we studied donor risk factors in 248 living kidney donor-recipient pairs. Unadjusted donor (125)I-iothalamate GFR (iGFR), donor age more than 45 years, donor total cholesterol level less than 200 mg/dL, and donor systolic blood pressure (SBP) less than 120 mm Hg were correlated with allograft estimated glomerular filtration rate (eGFR), and incidence of acute rejection (AR), delayed graft function and/or graft loss at 2 years posttransplantation. Donor iGFR less than 110 mL/min (slope=-7.40, P<0.01), donors more than 45 years (slope=-8.76, P<0.01), donor total cholesterol levels more than 200 mg/dL (slope=-10.03, P<0.01), and SBP more than 120 mm Hg (slope=-5.60, P=0.03) were associated with lower eGFR. By multivariable linear regression analysis these variables remained independently associated with lower eGFR, and poorer outcomes. The increasing number of donor factors (age, iGFR, cholesterol, and blood pressure) was directly associated with worse posttransplant eGFR (P<0.01). In conclusion, our data suggest that routine assessment of living donor parameters could supplement the consideration of recipient characteristics in predicting posttransplant risk of graft injury/dysfunction.

Safety of donor in adult-to-adult living donor liver transplantation using right lobe graft

BACKGROUND

The growing gap between the number of patients awaiting liver transplantation and available organs has continued to be the primary issue facing the transplant community. To overcome the waiting list mortality, living donor liver transplantation has become an option, in which the greatest concern is the safety of the donor, especially in adult-to-adult living donor liver transplantation (A-A LDLT) using a right lobe liver graft.

OBJECTIVE

We evaluated the safety of donors after right lobe liver donation for A-A LDLT performed in our center.

METHODS

From January 2002 to March 2006, 26 patients underwent A-A LDLT using right lobe liver grafts in our center. Seven donors were men and 19 were women (range, 19-65 years; median age, 38 years). The right lobe liver grafts were obtained by transecting the liver on the right side of the middle hepatic vein without interrupting the vascular blood flow. The mean follow-up time for these donors was 9 months.

RESULTS

These donor residual liver volumes ranged from 30.5% to 60.3%. We did not experience any donor mortality. Two cases (7.69%) experienced major complications: intra-abdominal bleeding and portal vein thrombosis in one each and three (11.54%), minor ones: wound steatosis in two, and transient chyle leak in one. All donors were fully recovered and returned to their previous occupations.

CONCLUSIONS

A-A LDLT using a right lobe liver graft has become a standard option. The donation of right lobe liver for A-A LDLT was a relatively safe procedure in our center.

Reduced mortality with right-lobe living donor compared to deceased-donor liver transplantation when analyzed from the time of listing

Right lobe living donor liver transplantation (RLDLT) is not yet a fully accepted therapy for patients with end-stage liver failure in the Western hemisphere because of concerns about donor safety and inferior recipient outcomes. An outcome analysis from the time of listing for all adult patients who were listed for liver transplantation (LT) at our center was performed. From 2000 to 2006, 1091 patients were listed for LT. One hundred fifty-four patients (LRD; 14%) had suitable live donors and 153 (99%) underwent RLDLT. Of the remaining patients (DD/Waiting List; n = 937), 350 underwent deceased donor liver transplant (DDLT); 312 died or dropped off the waiting list; and 275 were still waiting at the time of this analysis. The LRD group had shorter mean waiting times (6.0 months vs. 9.8 months; p < 0.001). Although medical model for end-stage liver disease (MELD) scores were similar at the time of listing, MELD scores at LT were significantly higher in the DD/Waiting List group (15.4 vs. 19.5; p = 0.002). Patients in Group 1 had a survival advantage with RLDLT from the time of listing (1-year survival 90% vs. 80%; p < 0.001). To our knowledge, this is the first report to document a survival advantage at time of listing for RLDLT over DDLT.

[Living related liver transplantation - analysis of the first 102 cases]

THE AIM

of the study was to analyse the first 102 living-related liver transplantations performed in Poland at the Children's Memorial Health Institute.

MATERIAL

between November 1999 and January 2007 102 living-related liver transplantations were carried out in 101 patients. In 63 the patients the indication for liver transplantation was biliary atresia, in 7 - intrahepatic cholestasis, in 11 - acute liver failure, in 9 - hepatic tumour, in two - graft insufficiency. The remaining indications included hepatic cirrosis in course of cystic fibrosis, Caroli disease and biliary cysts. There were 61 girls and 40 boys aged from 4 months to 11 years (mean 2.5 years). The body weight ranged from 4.5 to 31 kg (mean 12 kg).

RESULTS

eighty seven children are alive (86%). Five died in the early posttranplant period (between 2 and 11 days after operation), 9 died in the later period (from 36 days to 5 years and 10 months after the operation). The most serious, life threatening early and late complications were bacterial infections. The most frequent scheme of immunosuppressive treatment was tacrolimus and corticosteroids (64%) and tacrolimus and mycophenolate mofetil (16%).

CONCLUSION

living-related liver transplantation is an effective method of treatment of acute and end-stage liver diseases in children with low body mass.

Expanded criteria donor kidneys: evolution and current practice

Kidney transplantation is a well-established therapy for chronic renal failure, but its application is limited primarily by the availability of transplantable organs. The number of wait-listed patients continues to grow, and aggressive attempts to increase the numbers of transplants performed have failed to keep pace with demand. The continuing disparity between the demand for kidney transplants and the supply of organs has made efficient use of organs critical, forcing the transplant community to use organs from higher-risk donors than would previously have been considered. The precise definition of some marginal kidneys as expanded criteria donor kidneys was based on objective parameters and intended to expand the donor pool. This article reviews the development and definition of expanded criteria donor kidneys and the current strategies and outcomes associated with their use.

The economic impact of the utilization of liver allografts with high donor risk index

The disparity between the organ supply and the demand for liver transplantation (LT) has resulted in the growing utilization of 'marginal donor' organs. While economic outcomes for subsets of 'marginal' organs have been described for renal transplantation, similar analyses have not been performed for LT. Using UNOS data for 17 710 LTs performed between 2002 and 2005, we assessed the relationship between recipient model for end-stage liver disease (MELD) score, organ quality as defined by donor risk index (DRI, Feng et al. 2005) and hospital length of stay (LOS). Single-center cost-accounting data for 338 liver transplants were then analyzed with a multivariate linear regression model to determine the estimated cost associated with a day of LOS. Overall, 8.4% of donor organs were classified as high risk (DRI > 2-2.5) and 1.9% as very high risk (DRI > 2.5). In the lowest MELD group (0-10), the LOS difference between 'ideal' donors (DRI < 1.0) and very high risk (DRI > 2.5) was 10.6 days which was associated with an estimated incremental cost of $47 986. For patients with MELD >35, the average LOS increased from 23.2 to 41.8 days when very high DRI donors were used, resulting in an estimated increase in cost of nearly $84 000. We conclude that the use of marginal liver grafts results in increased hospital costs independent of recipient risk factors.

Living Donor Kidney Transplantation: The Effects of Donor Age and Gender on Short- and Long-Term Outcomes

BACKGROUND

The influence of donor age and sex on acute rejection episodes and short- and long-term graft survival in living donor (LD) kidney transplantation has not been well characterized.

METHODS

This prospective cohort study includes 739 first time LD transplantations with median follow-up time of 55.1 months. Death censored graft survival according to donor age and sex was compared with Kaplan-Meier plots. Cox regression was performed to estimate the association between different risk factors and graft survival and acute rejection episodes.

RESULTS

Graft survival was not affected by donor age above 50 years as long as these recipients did not experience an early acute rejection episode. Acute rejection episodes increased in recipients of grafts from donors > or =65 years (P=0.009). Donor age > or =65, recipient age less than 50 years, human leukocyte antigen (HLA)-DR matching, and female donor gender were risk factors for early acute rejection episodes. In multivariate analysis donor age > or =65 years was a risk factor for graft loss in all time periods after transplantation. During the first 5 years after transplantation a steroid resistant rejection episode was an additional risk factor. More than 5 years after transplantation male donor gender was the only additional risk factor for graft loss.

CONCLUSION

These results support the continued use of older male and female living donors who meet carefully constructed medical criteria and who are highly motivated to donate. Furthermore, donor age seems to be a more important predictor of graft loss than donor sex.

Organ Donation in Latin America

Recently in Latin America, there has been a strong influence of the "Spanish model" of organ procurement. In 2001, The "Punta Cana Group" was created by Latin American transplantation coordinators with the objective of registering and improving the system of donation and procurement. In many countries there is no universal financial support from the government for medical treatment, including dialysis and transplantation. In other countries there is complete financial support for all of the population, including immunosuppressive drugs. Practically all countries have transplantation laws that follow ethical concepts, such as brain death diagnosis criteria, forms of consent, criteria of allocation, and inhibition of commerce. The rate of potential donors notified in countries that perform transplantations with deceased donors varied from 6 to 47 per million population yearly (pmp/y); The rate of effective donors varied from 1 to 20 pmp. In 2004, the mean rate of effective donors in Latin America was 5.4 pmp. The family refusal rate for the donation of organs varied from 28% in Uruguay to 70% in Peru. In some countries, such as Puerto Rico, Uruguay, and Cuba, it was more than 15 pmp, whereas in others countries deceased donors were practically not used. The number of patients on the waiting list for solid organ transplants in 12 Latin American countries is 55,000. Although the donation rate has increased by 100% during the last 10 years, it is lower than that in Europe (15 pmm/y) or the United States (20 pmp/y).

Risk factors associated with the onset and progression of posttransplantation diabetes in renal allograft recipients

OBJECTIVE

The aim of this study was to assess the incidence of posttransplantation diabetes mellitus (PTDM) in renal allograft recipients and to investigate factors contributing to the onset and progression of PTDM and its underlying pathogenic mechanism(s).

RESEARCH DESIGN AND METHODS

A total of 77 patients with normal glucose tolerance (NGT) were enrolled in this study. An oral glucose tolerance test was performed 1 week before transplantation and repeated at 1 and 7 years after transplantation.

RESULTS

The overall incidence of PTDM was 39% at 1 year and 35.1% at 7 years posttransplantation. The incidence for each category of PTDM was as follows: persistent PTDM (P-PTDM) (patients who developed diabetes mellitus within 1 year of transplantation and remained diabetic during 7 years), 23.4%; transient PTDM (T-PTDM) (patients who developed diabetes mellitus during the 1st year after transplantation but eventually recovered to have NGT), 15.6%; late PTDM (L-PTDM) (patients who developed diabetes mellitus later than 1 year after transplantation), 11.7%; and non-PTDM during 7 years (N-PTDM7) (patients who did not develop diabetes mellitus during 7 years), 49.3%. Older age (> or = 40 years) at transplantation was a higher risk factor for P-PTDM, whereas a high BMI (> or = 25 kg/m2) and impaired fasting glucose (IFG) at 1 year posttransplantation were higher risk factors for L-PTDM. Impaired insulin secretion rather than insulin resistance was significantly associated with the development of P- and L-PTDM.

CONCLUSIONS

Impaired insulin secretion may be the main mechanism for the development of PTDM. Older age at transplantation seems to be associated with P-PTDM, whereas a high BMI and IFG at 1 year after transplantation were associated with L-PTDM.