Associations of body mass index and weight loss with mortality in transplant-waitlisted maintenance hemodialysis patients

A body mass index (BMI) below morbid obesity range is often a requirement for kidney transplant wait-listing, but data linking BMI changes to mortality during the waitlist period are lacking. By linking the 6-year (7/2001-6/2007) national databases of a large dialysis organization and the Scientific Registry of Transplant Recipients, we identified 14 632 waitlisted hemodialysis patients without kidney transplantation. Time-dependent survival models examined the mortality predictability of 13-week-averaged BMI, pretransplant serum creatinine as a muscle mass surrogate and their changes over time. The patients were on average 52 ± 13 years old, 40% women and had a BMI of 26.9 ± 6.3 kg/m². Each kg/m² increase of BMI was associated with a death hazard ratio (HR) of 0.96 (95%CI: 0.95-0.97). Compared to the lowest creatinine quintile, the 4th and 5th quintiles had death HRs of 0.75 (0.66-0.86) and 0.57 (0.49-0.66), respectively. Compared to minimal (< ± 1 kg) weight change over 6 months, those with 3 kg- < 5 kg and ≥ 5 kg weight loss had death HRs of 1.31 (1.14-1.52) and 1.51 (1.30-1.75), respectively. Similar associations were observed with creatinine changes over time. Transplant-waitlisted hemodialysis patients with lower BMI or muscle mass and/or unintentional weight or muscle loss have higher mortality in this observational study. Impact of intentional weight change remains unclear.

Outcomes of simultaneous pancreas-kidney transplantation in type 2 diabetic recipients

BACKGROUND AND OBJECTIVES

Type 2 diabetic patients with end-stage renal disease may receive a simultaneous pancreas-kidney (SPK) transplant. However, outcomes are not well described. Risks for death and graft failure were examined in SPK type 2 diabetic recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the United Network for Organ Sharing database, outcomes of SPK transplants were compared between type 2 and type 1 diabetic recipients. All primary SPK adult recipients transplanted between 2000 and 2007 (n=6756) were stratified according to end-stage pancreas disease diagnosis (type 1: n=6141, type 2: n=582). Posttransplant complications and risks for death and kidney/pancreas graft failure were compared.

RESULTS

Of the 6756 SPK transplants, 8.6% were performed in recipients with a type 2 diabetes diagnosis. Rates of delayed kidney graft function and primary kidney nonfunction were higher in the type 2 diabetics. Five-year overall and death-censored kidney graft survival were inferior in type 2 diabetics. After adjustment for other risk factors, including recipient (age, race, body weight, dialysis time, and cardiovascular comorbidities), donor, and transplant immune characteristics, type 2 diabetes was not associated with increased risk for death or kidney or pancreas failure when compared with type 1 diabetic recipients.

CONCLUSIONS

After adjustment for other risk factors, SPK recipients with type 2 diabetes diagnosis were not at increased risk for death, kidney failure, or pancreas failure when compared with recipients with type 1 diabetes.

Associations of pretransplant weight and muscle mass with mortality in renal transplant recipients

BACKGROUND AND OBJECTIVES

The association between pretransplant body composition and posttransplant outcomes in renal transplant recipients is unclear. It was hypothesized that in hemodialysis patients higher muscle mass (represented by higher pretransplant serum creatinine level) and larger body size (represented by higher pretransplant body mass index [BMI]) are associated with better posttransplant outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Linking 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, 10,090 hemodialysis patients were identified who underwent kidney transplantation from July 2001 to June 2007. Cox regression hazard ratios and 95% confidence intervals of death and/or graft failure were estimated.

RESULTS

Patients were 49 ± 13 years old and included 49% women, 45% diabetics, and 27% African Americans. In Cox models adjusted for case-mix, nutrition-inflammation complex, and transplant-related covariates, the 3-month-averaged postdialysis weight-based pretransplant BMI of 20 to <22 and < 20 kg/m(2), compared with 22 to <25 kg/m(2), showed a nonsignificant trend toward higher combined posttransplant mortality or graft failure, and even weaker associations existed for BMI ≥ 25 kg/m(2). Compared with pretransplant 3-month- averaged serum creatinine of 8 to <10 mg/dl, there was 2.2-fold higher risk of combined death or graft failure with serum creatinine <4 mg/dl, whereas creatinine ≥14 mg/dl exhibited 22% better graft and patient survival.

CONCLUSIONS

Pretransplant obesity does not appear to be associated with poor posttransplant outcomes. Larger pretransplant muscle mass, reflected by higher pretransplant serum creatinine level, is associated with greater posttransplant graft and patient survival.

Risk factors for development of new-onset diabetes mellitus after transplant in adult lung transplant recipients

The objectives of this study are to examine the incidence of new-onset diabetes mellitus after transplant (NODAT) and to identify its risk factors in adult lung transplant recipients using the Organ Procurement and Transplant Network/United Network of Organ Sharing database. Between July 2004 and December 2007, a total of 3540 adults (≥18 yr old) received their first single- or double-lung transplant alone and had at least one follow-up report of post-transplant diabetic status. Among these, 2991 recipients were identified as not having diabetes mellitus (DM) pre-transplant. Risk factors for NODAT were examined. DM was newly reported in 33.4% of the 2991 recipients over the median follow-up time of 670 d. Significant independent risk factors for the development of NODAT included male gender (HR = 1.15), recipient age ≥50 (1.46), African American (1.39), higher body mass index (1.51 for ≥30 vs. 18-25), cystic fibrosis (3.30), and tacrolimus use at discharge (1.67). NODAT occurred in a third of adult lung transplant recipients during the median follow-up period. Some of the risk factors for NODAT after lung transplant are similar to those reported in other solid-organ transplants. Cystic fibrosis is a strong risk factor for development of NODAT after lung transplant.

Pretransplant risk factors for new-onset diabetes mellitus after transplant in pediatric liver transplant recipients

Our objectives are to examine the incidence of new-onset diabetes mellitus after transplant (NODAT) and to identify its risk factors in pediatric liver transplant recipients using the Organ Procurement and Transplant Network/United Network for Organ Sharing database. Between July 2004 and December 2008, a total of 1214 children (2-20 years old) received their first liver transplant alone, and had at least 1 follow-up report of posttransplant diabetic status. Among these, 1161 recipients were identified as not having diabetes mellitus before transplant. Risk factors for NODAT were examined using classification and regression tree and multivariate Cox regression analysis. Diabetes mellitus was newly reported in 10.1% of the 1161 recipients over the median follow-up time of 770 days. The cumulative incidences of NODAT at 1, 2, and 3 years after transplant were 5.9%, 8.3%, and 11.2%, respectively. More than 50% of recipients with cystic fibrosis developed NODAT. In recipients without cystic fibrosis, independent risk factors for NODAT included increased recipient age (compared to 2-5 years, hazard ratio = 3.09 for 5-13 years, p = 0.02; 7.14 for ≥13 years, p < 0.001), African American race (1.97, p = 0.003), and primary diagnosis of primary sclerosing cholangitis (2.24, p = 0.02) and acute hepatic necrosis (1.89, p = 0.04). In conclusion, NODAT occurred in one-tenth of pediatric liver transplant recipients in the United States during the median follow-up of 2 years. Some of the risk factors for NODAT in pediatric liver transplant recipients are similar to those reported in other solid organ transplants. Underlying liver disease of cystic fibrosis, primary sclerosing cholangitis, and acute hepatic necrosis are independent risk factors for NODAT in pediatric liver transplant recipients.

Associations of pretransplant diabetes mellitus, new-onset diabetes after transplant, and acute rejection with transplant outcomes: an analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database

BACKGROUND

Diabetes and acute rejection are major contributors to morbidity and mortality in kidney transplant recipients. Immunosuppressive medications decrease acute rejection, but increase the frequency of new-onset diabetes after transplant. Our objective was to investigate the joint associations of diabetes (pretransplant diabetes and new-onset diabetes after transplant) and acute rejection with transplant outcomes in a recent transplant cohort.

STUDY DESIGN

Historical cohort study.

SETTING & PARTICIPANTS

37,448 recipients (age ≥ 18 years; 2004-2007) surviving with a functioning transplant for longer than 1 year were identified in the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database as of May 22, 2009.

PREDICTORS

Recipients were stratified into 6 mutually exclusive groups according to status of diabetes and acute rejection at 1 year: group 1, neither (reference; n = 20,964); group 2, new-onset diabetes alone (n = 2,140); group 3, pretransplant diabetes alone (n = 10,730); group 4, acute rejection alone (n = 2,282); group 5, new-onset diabetes and acute rejection (n = 361); and group 6, pretransplant diabetes and acute rejection (n = 1,061). Analyses were adjusted for other recipient, donor, and transplant characteristics. OUTCOMES MEASUREMENTS: Multivariate Cox regression analysis of time to transplant failure (overall and death censored) and mortality (all-cause and cardiovascular).

RESULTS

Median follow-up after 1 year was 548 days (25th-75th percentiles, 334-752 days). During this time, there were 3,047 outcomes of overall transplant failure. New-onset diabetes alone (group 2) was not associated significantly with any study outcomes. Groups 3-6 were associated with higher overall transplant failure risk. However, only groups 4-6 were associated with higher death-censored transplant failure risk. Group 3, 4, and 6 were associated with higher all-cause mortality risk, whereas only groups 3 and 6 were associated with higher cardiovascular mortality risk.

LIMITATIONS

Potential information bias with exposure, covariable, or outcome misclassification; relatively short follow-up.

CONCLUSIONS

Pretransplant diabetes is the major predictor of all-cause and cardiovascular mortality, and acute rejection during the first year is the major predictor of death-censored transplant failure in kidney recipients surviving with a functioning transplant for at least 1 year. The influence of new-onset diabetes on long-term outcomes needs further observation.

Induction therapy in pediatric kidney transplant recipients discharged with a triple drug immunosuppressive regimen

We evaluated the effectiveness of induction therapy on transplant outcomes during 2004-2007 in the United States. We retrospectively reviewed OPTN/UNOS registry and selected kidney pediatric (<21-yr) recipients that received no induction (NoIND), IL-2RA, or rabbit anti-THY and were discharged with a triple drug immunosuppressive maintenance regimen, including steroids. Of 2932 recipients, 20%, 36%, and 43% were in NoIND, THY, and IL-2RA groups, respectively. The majority received tacrolimus (88%) and MMF (89%) at discharge. There was no association of induction with the risk of acute rejection even after adjusting for known cofounders. Compared to NoIND, IL2-RA, but not THY, had a modest decrease (3%) in absolute rate of graft loss and was associated with a risk reduction ratio of 0.51 (95% CI, 0.31-0.84) in one-yr graft loss. At three yr, no induction agent was associated with decreased graft loss. In conclusion, induction agents were used in 80% of pediatric kidney recipients discharged with a triple drug immunosuppressive maintenance regimen between 2004-2007 in the United States. Neither THY nor IL-2RA was associated with reduced rejection episodes. The use of induction therapy was not associated with improvement in three-yr graft survival.

Outcomes of simultaneous heart-kidney transplant in the US: a retrospective analysis using OPTN/UNOS data

Simultaneous heart-kidney transplantation (SHK) remains uncommon in the US. We examined outcomes of SHK compared to heart transplant alone (HTA) and deceased donor kidney transplant (DDKT). Data from OPTN/UNOS heart and kidney data bases were used to identify 16,710 HTA, 263 SHK transplants and 68,833 DDK transplants between 1998 and 2007. Outcomes included patient survival (PS), acute cardiac and renal rejection and renal graft survival (rGS). The adjusted risk of death was 44% lower with SHK compared to HTA. Over half of SHK were performed in cases where pretransplant dialysis was not initiated. In these cases, there was no significant difference in the risk of death between SHK and HTA (HR 1.01; 95% CI 0.67-1.50). Recipients of SHK had worse 1-year rGS and PS and had a higher relative risk of overall renal graft loss compared to DDKT recipients. One-year rates of cardiac (14.5%) and renal (6.5%) rejection were lower in SHK compared to HTA and DDKT, respectively. Recipients of SHK had a lower adjusted risk of death compared to HTA recipients, particularly in patients who required pretransplant dialysis. These data suggest that SHK should be considered in heart transplant candidates with renal failure requiring dialysis, whereas the utility of SHK in cases of renal failure not requiring dialysis warrants further study.

Predictive ability of pretransplant comorbidities to predict long-term graft loss and death

Whether to include additional comorbidities beyond diabetes in future kidney allocation schemes is controversial. We investigated the predictive ability of multiple pretransplant comorbidities for graft and patient survival. We included first-kidney transplant deceased donor recipients if Medicare was the primary payer for at least one year pretransplant. We extracted pretransplant comorbidities from Medicare claims with the Clinical Classifications Software (CCS), Charlson and Elixhauser comorbidities and used Cox regressions for graft loss, death with function (DWF) and death. Four models were compared: (1) Organ Procurement Transplant Network (OPTN) recipient and donor factors, (2) OPTN + CCS, (3) OPTN + Charlson and (4) OPTN + Elixhauser. Patients were censored at 9 years or loss to follow-up. Predictive performance was evaluated with the c-statistic. We examined 25 270 transplants between 1995 and 2002. For graft loss, the predictive value of all models was statistically and practically similar (Model 1: 0.61 [0.60 0.62], Model 2: 0.63 [0.62 0.64], Models 3 and 4: 0.62 [0.61 0.63]). For DWF and death, performance improved to 0.70 and was slightly better with the CCS. Pretransplant comorbidities derived from administrative claims did not identify factors not collected on OPTN that had a significant impact on graft outcome predictions. This has important implications for the revisions to the kidney allocation scheme.

Living donor kidney versus simultaneous pancreas-kidney transplant in type I diabetics: an analysis of the OPTN/UNOS database

BACKGROUND AND OBJECTIVES

Transplant options for type I diabetics with end-stage renal disease include simultaneous pancreas-kidney (SPKT), living donor kidney (LDKT), and deceased donor kidney transplant (DDKT). It is unclear whether SPKT offers a survival benefit over LDKT in the current era of transplantation. The authors compared outcomes of kidney transplant recipients with type I diabetes using data from the Organ Procurement and Transplant Network/United Network for Organ Sharing.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adult (age 20 to 59) type I diabetics who received a solitary first-time kidney transplant between 2000 and 2007 were studied. Outcomes included overall kidney graft and patient survival. Multivariate analysis was performed using a stepwise Cox proportional hazards model.

RESULTS

Kidney graft survival was better for recipients of LDKT compared with SPKT (P = 0.008), although patient survival was similar (P = 0.346). On multivariate analysis, LDKT was associated with lower adjusted risks over 72 mo follow-up of kidney graft failure (HR 0.71; 95% CI 0.61 to 0.83) and patient death (HR 0.78; 95% CI 0.65 to 0.94) versus SPKT. Compared with DDKT, SPKT had superior unadjusted kidney graft and patient survival, partly due to favorable SPKT donor and recipient factors.

CONCLUSIONS

Despite more transplants from older donors and among older recipients, LDKT was associated with superior outcomes compared with SPKT and was coupled with the least wait time and dialysis exposure. LDKT utilization should be considered in all type I diabetics with an available living donor, particularly given the challenges of ongoing organ shortage.

Fluid retention is associated with cardiovascular mortality in patients undergoing long-term hemodialysis

BACKGROUND

Patients with chronic kidney disease (stage 5) who undergo hemodialysis treatment have similarities to heart failure patients in that both populations retain fluid frequently and have excessively high mortality. Volume overload in heart failure is associated with worse outcomes. We hypothesized that in hemodialysis patients, greater interdialytic fluid gain is associated with poor all-cause and cardiovascular survival.

METHODS AND RESULTS

We examined 2-year (July 2001 to June 2003) mortality in 34,107 hemodialysis patients across the United States who had an average weight gain of at least 0.5 kg above their end-dialysis dry weight by the time the subsequent hemodialysis treatment started. The 3-month averaged interdialytic weight gain was divided into 8 categories of 0.5-kg increments (up to > or =4.0 kg). Eighty-six percent of patients gained >1.5 kg between 2 dialysis sessions. In unadjusted analyses, higher weight gain was associated with better nutritional status (higher protein intake, serum albumin, and body mass index) and tended to be linked to greater survival. However, after multivariate adjustment for demographics (case mix) and surrogates of malnutrition-inflammation complex, higher weight-gain increments were associated with increased risk of all-cause and cardiovascular death. The hazard ratios (95% confidence intervals) of cardiovascular death for weight gain <1.0 kg and > or =4.0 kg (compared with 1.5 to 2.0 kg as the reference) were 0.67 (0.58 to 0.76) and 1.25 (1.12 to 1.39), respectively.

CONCLUSIONS

In hemodialysis patients, greater fluid retention between 2 subsequent hemodialysis treatment sessions is associated with higher risk of all-cause and cardiovascular death. The mechanisms by which fluid retention influences cardiovascular survival in hemodialysis may be similar to those in patients with heart failure and warrant further research.

Transplant tourism in the United States: a single-center experience

BACKGROUND AND OBJECTIVES

Transplant "tourism" typically refers to the practice of traveling outside the country of residence to obtain organ transplantation. This study describes the characteristics and outcomes of 33 kidney transplant recipients who traveled abroad for transplant and returned to University of California, Los Angeles (UCLA) for follow-up.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

Posttransplantation outcomes were compared between tourists and a matched cohort of patients who underwent transplantation at UCLA (matched for age, race, transplant year, dialysis time, previous transplantation, and donor type). Median follow-up time was 487 d (range 68 to 3056).

RESULTS

Compared with all patients who underwent transplantation at UCLA, tourists included more Asians and had shorter dialysis times. Most patients traveled to their region of ethnicity with the majority undergoing transplantation in China (44%), Iran (16%), and the Philippines (13%). Living unrelated transplants were most common. Tourists presented to UCLA a median of 35 d after transplantation. Four patients required urgent hospitalization, three of whom lost their grafts. Seventeen (52%) patients had infections, with nine requiring hospitalization. One patient lost her graft and subsequently died from complications related to donor-contracted hepatitis B. One-year graft survival was 89% for tourists and 98% for the matched UCLA cohort (P = 0.75). The rate of acute rejection at 1 yr was 30% in tourists and 12% in the matched cohort.

CONCLUSIONS

Tourists had a more complex posttransplantation course with a higher incidence of acute rejection and severe infectious complications.

Impact of gastrointestinal-related side effects on mycophenolate mofetil dosing and potential therapeutic strategies

In renal transplant patients receiving mycophenolate mofetil (MMF), maintaining an adequate dosing regimen has been shown to maximize short- and long-term outcomes. Gastrointestinal (GI) adverse events associated with MMF are frequent, and lead to MMF dose reduction or withdrawal in 40-50% of cases. Among MMF-treated patients experiencing GI complications, one analysis has reported MMF discontinuation to be associated with almost a threefold increase in risk of graft loss, while a dose reduction > or = 50% carried over a twofold increase in risk. If GI symptoms improve and the pre-reduction MMF dose is resumed the increased risk of graft loss may be reversed, but continuing intolerance can make this difficult to achieve. Investigation of contributing factors is important and may alleviate symptoms. Conversion to enteric-coated mycophenolate sodium (EC-MPS) may be an effective option. Two open-label studies using patient-reported outcomes data have shown a significant and clinically relevant benefit in GI-related symptom burden after conversion from MMF to EC-MPS. In conclusion, monitoring of GI complications is essential following renal transplantation, and maintaining adequate mycophenolic acid exposure should be a priority when considering treatment options.

Can machine perfusion decrease the likelihood of discard among biopsied kidneys?

Many factors, such as donor risk factors and renal function, have been shown to be associated with an increased likelihood of discard after recovering kidneys from deceased donors. When these factors are insufficient for assessment, renal biopsy is often performed at the time of harvest to assess suitability. Our aims were to identify factors that predict the discard of a biopsied kidney and to assess the impact of machine perfusion (MP) on kidney discard. We biopsied 678 kidneys from deceased donors aged >or=40 years from 2001 to 2006. We used a logistic regression model to estimate the adjusted odds ratios for kidney discard. Thirty-nine percent (n = 261) of biopsied kidneys were discarded. Kidneys with glomerulosclerosis (GS) > 20% had the highest likelihood of discard. Other significant predictors of discard included extreme donor age, final resistance (>40), atherosclerosis, interstitial fibrosis, arteriolosclerosis, and terminal serum creatinine value (SCr) > 1.5 mg/dL. MP kidneys (n = 69) were less likely to be discarded than cold storage (CS) kidneys after adjusting for other factors (adjusted odds ratio = .13, P < .001). In conclusion, abnormal biopsy findings were associated with the highest likelihood of discard. MP was used in only 10% of the cases; however, the use of MP was associated with a decreased likelihood of discard among biopsied kidneys.

Outcomes of kidney transplantation from older living donors to older recipients

BACKGROUND

More than half the newly wait-listed patients for kidney transplantation in 2005 were older than 50 years, and 13% were older than 65 years. As waiting times for a deceased donor kidney increase, these older candidates are disadvantaged by rapidly deteriorating health, often resulting in death or removal from the wait list before transplantation.

STUDY DESIGN

An observational cohort study was conducted using data from the Organ Procurement Transplant Network/United Network for Organ Sharing.

SETTING & PARTICIPANTS

All adult kidney-only transplantations performed in recipients 60 years and older from 1996 to 2005 were included.

PREDICTOR

The recipient cohort was stratified into 4 groups based on donor source: older living donor (OLD: living donor age > 55 years), younger living donor (YLD: living donor age </= 55 years), standard criteria deceased donor (SCD), and expanded criteria deceased donor (ECD).

OUTCOMES & MEASUREMENTS

Early posttransplantation outcomes, graft survival, patient survival, renal function 1 year posttransplantation, and relative risk of graft loss and patient death were compared.

RESULTS

Of 23,754 kidney transplantations performed in recipients 60 years and older, 7,006 were living donor transplantations (1,133 were > 55 years [OLD] and 5,873 were <or= 55 years [YLD]), 12,197 from SCDs, and 4,551 from ECDs. Early posttransplantation outcomes were best in YLD transplantations, followed by SCD and OLD transplantations. OLD transplantations were associated with inferior 3-year graft survival rates (85.7%), but similar 3-year patient survival rates (88.4%) compared with YLD (3-year graft survival, 83.4%; patient survival, 87.4%) and had superior graft survival compared with all deceased donor options. Compared with OLD transplantations, ECD transplantations were associated with a greater risk of graft loss (hazard ratio, 2.36; 95% confidence interval, 1.18 to 4.74).

LIMITATIONS

Observational retrospective studies using registry data are subject to inherent limitations, including the possibility of selection bias.

CONCLUSIONS

With superior graft and patient survival in recipients of transplants from OLDs compared with SCDs and ECDs, OLDs may be an important option for elderly transplantation candidates and should be considered for older patients with a willing and suitable older donor.

Incidence and risk factors for diarrhea following kidney transplantation and association with graft loss and mortality

BACKGROUND

Gastrointestinal complications after kidney transplantation are associated with inferior graft outcomes. We examined the incidence, risk factors, and outcomes of posttransplantation diarrhea.

STUDY DESIGN

Historic cohort study.

SETTING & PARTICIPANTS

We examined first kidney transplant recipients in the United States from 1995 to 2002, with follow-up through December 2002. Recipients of multiple organs were excluded. We limited our study population to Medicare beneficiaries.

PREDICTORS

Recipient, donor, and transplant characteristics were ascertained by means of US Renal Data System database inquiry.

OUTCOMES

Incidence of diarrhea, graft loss, and death after transplantation. First episodes of diarrhea after transplantation were ascertained by using International Classification of Disease, Ninth Revision, Clinical Modification codes using Medicare billing data. Cause of diarrhea was classified as infectious or not and according to specific cause. Graft loss and death were ascertained from the date of the first diarrhea episode.

RESULTS

We enrolled 41,442 patients. Mean follow-up was 758 +/- 399 days. We observed 7,103 diarrhea cases and 8,104 graft losses (4,201 deaths). The 3-year cumulative incidence of diarrhea was 22%, with 18% diagnosed as noninfectious diarrhea with an unspecified cause. Using multivariate Cox proportional hazards analysis, factors associated with increased risk of unspecified noninfectious diarrhea were female sex (hazard ratio [HR], 1.40; 95% confidence interval, 1.33 to 1.48), type 1 diabetes (HR, 1.20; 95% confidence interval, 1.06 to 1.37), and regimens containing tacrolimus and mycophenolate mofetil (HR, 1.37; 95% confidence interval, 1.28 to 1.46). Unspecified noninfectious diarrhea was associated with increased risk of graft failure (HR, 2.13; 95% confidence interval, 1.98 to 2.28) and patient death (HR, 2.04; 95% confidence interval, 1.85 to 2.24).

LIMITATIONS

Use of claims data to ascertain patient characteristics and events; inability to make causal inference based on retrospective designs.

CONCLUSIONS

Regimens containing tacrolimus and mycophenolate mofetil were associated with increased risk of noninfectious diarrhea. Episodes of noninfectious diarrhea doubled the hazard of graft loss and patient death.

Incidence and risk factors for diarrhea following kidney transplantation and association with graft loss and mortality

BACKGROUND

Gastrointestinal complications after kidney transplantation are associated with inferior graft outcomes. We examined the incidence, risk factors, and outcomes of posttransplantation diarrhea.

STUDY DESIGN

Historic cohort study.

SETTING & PARTICIPANTS

We examined first kidney transplant recipients in the United States from 1995 to 2002, with follow-up through December 2002. Recipients of multiple organs were excluded. We limited our study population to Medicare beneficiaries.

PREDICTORS

Recipient, donor, and transplant characteristics were ascertained by means of US Renal Data System database inquiry.

OUTCOMES

Incidence of diarrhea, graft loss, and death after transplantation. First episodes of diarrhea after transplantation were ascertained by using International Classification of Disease, Ninth Revision, Clinical Modification codes using Medicare billing data. Cause of diarrhea was classified as infectious or not and according to specific cause. Graft loss and death were ascertained from the date of the first diarrhea episode.

RESULTS

We enrolled 41,442 patients. Mean follow-up was 758 +/- 399 days. We observed 7,103 diarrhea cases and 8,104 graft losses (4,201 deaths). The 3-year cumulative incidence of diarrhea was 22%, with 18% diagnosed as noninfectious diarrhea with an unspecified cause. Using multivariate Cox proportional hazards analysis, factors associated with increased risk of unspecified noninfectious diarrhea were female sex (hazard ratio [HR], 1.40; 95% confidence interval, 1.33 to 1.48), type 1 diabetes (HR, 1.20; 95% confidence interval, 1.06 to 1.37), and regimens containing tacrolimus and mycophenolate mofetil (HR, 1.37; 95% confidence interval, 1.28 to 1.46). Unspecified noninfectious diarrhea was associated with increased risk of graft failure (HR, 2.13; 95% confidence interval, 1.98 to 2.28) and patient death (HR, 2.04; 95% confidence interval, 1.85 to 2.24).

LIMITATIONS

Use of claims data to ascertain patient characteristics and events; inability to make causal inference based on retrospective designs.

CONCLUSIONS

Regimens containing tacrolimus and mycophenolate mofetil were associated with increased risk of noninfectious diarrhea. Episodes of noninfectious diarrhea doubled the hazard of graft loss and patient death.

A retrospective analysis of immunosuppression compliance, dose reduction and discontinuation in kidney transplant recipients

We describe factors associated with poor compliance and dose reductions and examine the relative impact of compliance, dose reduction and discontinuation on graft outcome. Medicare claims for MMF in 7062 deceased donor renal recipients with at least 1 year of graft function were used to calculate compliance and dose reductions. Compliance was modeled using medication possession ratio to define quartiles for poor, low, medium and high compliance. The relative impact of compliance, dose reduction and discontinuation on graft outcome was assessed with Cox proportional hazards. Pediatric (Age 0-18, Odds ratio = 1.71, 95% CI 1.11-2.63, p = 0.014) and adolescent recipients (19-24, 1.57, 1.23-2.00, p < 0.001) were more likely poorly compliant compared to adults age 25-44. Poor compliance was also associated with physical limitations, hypertension, delayed graft function, rejection, infection and GI conditions. Poor (1.43, 1.11-1.84, p = 0.005) and low (1.46, 1.13-1.88, p = 0.004) compliance was associated with an increased hazard of graft loss as was >50% dose reduction (1.69, 1.15-2.50, p = 0.008) and discontinuation (8.34, 6.85-10.2, p < 0.001). Medication possession ratios lower than the 3-year mean were associated with an increased risk of graft loss. These results may indicate that interventions to improve compliance among kidney transplant recipients should strive for high rather than discourage low compliance.

Overview of renal transplantation

Kidney transplantation is the treatment of choice for end stage renal disease patients. Recent advances, including newer immunosuppressants, revision of organ allocation policies, and better medical care of renal transplant recipients, have resulted in an increase number of transplants with improved outcomes. The major obstacles include the lack of improvement in long term outcomes, shortage of organs and long-term morbidity of candidates with chronic kidney disease. This review highlights transplant immunology, organ allocation, immunosuppressive medications, and complications of transplantation involving post transplantation infections, diabetes, and cardiovascular disease.