Smith, Byron H.

AbstractHistologic findings on 1‐year biopsies such as inflammation with fibrosis and transplant glomerulopathy predict renal allograft loss by 5 years. However, almost half of the patients with graft loss have a 1‐year biopsy that is either normal or has only interstitial fibrosis. The goal of this study was to determine if there was a gene expression profile in these relatively normal 1‐year biopsies that predicted subsequent decline in renal function. Using transcriptome microarrays we measured intragraft mRNA levels in a retrospective Discovery cohort (170 patients with a normal/minimal fibrosis 1‐year biopsy, 54 with progressive decline in function/graft loss and 116 with stable function) and developed a nested 10‐fold cross‐validated gene classifier that predicted progressive decline in renal function (positive predictive value = 38 ± 34%%; negative predictive value = 73 ± 30%, c‐statistic = .59). In a prospective, multicenter Validation cohort (270 patients with Normal/Interstitial Fibrosis [IF]), the classifier had a 20% positive predictive value, 85% negative predictive value and .58 c‐statistic. Importantly, the majority of patients with graft loss in the prospective study had 1‐year biopsies scored as Normal or IF. We conclude predicting graft loss in many renal allograft recipients (i.e., those with a relatively normal 1‐year biopsy and eGFR > 40) remains difficult.

ObjectiveTo identify social determinants of health care that are associated with poorer pediatric well‐differentiated thyroid cancer (WDTC) outcomes and increased stage at presentation.Study DesignUsing the SEER database (Surveillance, Epidemiology, and End Results), we retrospectively gathered data on pediatric WDTC across the United States between 1973 and 2015.SettingAll patients between 0 and 19 years old with a diagnosis of WDTC were included.MethodsPatient variables were analyzed for relationships to AJCC stage at presentation (American Joint Committee on Cancer), overall survival, and disease‐specific survival.ResultsAmong 3913 patients with pediatric thyroid cancer, 3185 were female (81.4%), 3366 had papillary thyroid cancer (85.3%), and 367 had follicular thyroid cancer (9.4%). Two‐ and 5‐year overall and disease‐specific survival approached 100%. However, when outcomes were analyzed by specific populations, male sex, non‐Caucasian race, poverty, and language isolation were linked to worse overall survival. Male sex and poverty were associated with poorer disease‐specific survival. Regarding overall AJCC stage at presentation, male sex and Black race were related to higher overall presenting AJCC stage. Later AJCC T stage at presentation was seen in male, Hispanic, Asian, and Black patients. There were no variables significantly related to following through with recommended surgery.ConclusionPediatric WDTC continues to carry an excellent prognosis in the United States. However, when we consider specific populations, the social determinants of health care affect survival and disease burden at presentation: male sex, poverty, language isolation, and race affected survival and/or AJCC stage at presentation in pediatric WDTC.

Background. At 5 and 10 y after kidney transplantation, chronic histologic changes such as arteriolar hyalinosis and mesangial expansion are common; however, determining cause is difficult. We compared surveillance biopsies in living donor kidney transplants (LDKTx) from HLA-matched siblings (termed HLA-identical [HLA-ID]) with HLA non-ID to investigate which histologic changes were likely due to alloimmune injury and which were due to nonalloimmune injury. Methods. We performed a retrospective, cohort study comparing HLA-ID sibling LDKTx (n = 175) with HLA non-ID LDKTx (n = 175; matched for age, sex, and year of transplant ±2 y) performed at a single institution from March 1999 to November 2018. Results. Baseline characteristics and maintenance immunosuppression were similar. Mortality rates were similar, but in the HLA-ID group, 10-y death-censored graft survival was higher (93.8% versus 80.9% HLA non-ID LDKTx; P < 0.001), rejection rates were lower (after 1 y 9.6% versus 27.1%; P < 0.001), and Banff inflammation scores including glomerulitis and peritubular capillaritis were lower on surveillance biopsies at 1, 5, and 10 y. In contrast, chronic Banff scores (interstitial fibrosis, arteriolar hyalinosis, mesangial expansion, etc) were similar in prevalence and severity on surveillance biopsies at 1, 5, and 10 y. Conclusions. HLA-ID LDKTx have less inflammation and less transplant glomerulopathy, but most chronic histologic changes were similar to less well-matched LDKTx. We conclude that these types of chronic changes are not associated with HLA mismatches and may be due to nonimmunologic causes (hypertension, obesity, etc), suggesting that new management approaches to prevent these lesions may be needed.

AbstractDeath with a functioning graft and death‐censored renal allograft failure remain major problems for which effective preventative protocols are lacking. The retrospective cohort study aimed to determine whether histologic changes on a 5‐year surveillance kidney biopsy predict adverse outcomes after transplantation in recipients who had: both Type 2 diabetes (T2DM) and obesity (BMI ≥ 30 kg/m2) at the time of transplantation (T2DM/Obesity, n = 75); neither (No T2DM/No obesity, n = 78); No T2DM/Obesity (n = 41), and T2DM/No obesity (n = 47). On 5‐year biopsies, moderate‐to‐severe mesangial expansion was more common in the T2DM/Obesity group (Banff mm score ≥2 = 49.3%; Tervaert classification MS ≥ 2b = 26.7%) compared to the other groups (p < .001 for both scores). Risk factors included older age, higher BMI, HbA1C, and triglycerides at 1‐year post‐transplant. Moderate‐to‐severe mesangial expansion correlated with death with function (HR 1.74 (1.01, 2.98), p = .045 Banff and 1.89 (1.01, 3.51) p = .045 Tervaert) and with death‐censored graft loss (HR 3.2 (1.2, 8.8), p = .02 Banff and HR 3.8 (1.3, 11.5), p = .01 Tervaert) over a mean of 11.6 years of recipient follow‐up post‐transplant. These data suggest that mesangial expansion in recipients with T2DM and obesity may reflect systemic vascular injury and might be a novel biomarker to predict adverse outcomes post renal transplant.

Abstract INTRODUCTION: Type 1 Diabetes (T1D) patients have an increased risk for major adverse cardiovascular events (MACE). Pancreas Transplantation Alone (PTA) in patients with T1D achieves near normal glucose control for a prolonged period but limited data are available to date regarding MACE during a 10 year follow up period after the procedure. OBJECTIVE: We studied incidence of MACE after PTA in T1D patients over a 10 year follow-up period. METHODS: Retrospectively, we studied 113 T1D recipients of PTA at Mayo Clinic, Rochester with the procedure performed between January 1998 and August 2018 and follow up of at least 1 year. Data were collected before transplantation and up to 10 year follow up after the first PTA. MACE data were gathered until primary non function, re-transplantation, or complete loss of c-peptide (&lt;0.01ng/ml). We report vascular risk factors including hypertension, hyperlipidemia, smoking and BMI along with MACE (defined as cardiac events as unstable angina, Myocardial Infarction (MI), need for re-vascularization, cardiac death, cerebral events as Transient ischemic attack (TIA), stroke, need for re-vascularization and peripheral arterial disease as need for re-vascularization, gangrene and amputation). RESULTS: Eighteen subjects had pre-transplant MACE. A total of 14 subjects had graft failure within 24 to 36 hours due to thrombosis, with 3 in pre-transplant MACE cohort and 11 in no MACE cohort. Thus, we followed 99 subjects for the development of post-transplant MACE for a period of 6.3 ± 3.6 years. T1D subjects with MACE (n=15) had baseline characteristics: Age 48± 7.8 years, gender F/M 9/6,, duration of diabetes 33 ± 12 years, BMI 26± 3.1(Kg/m2), HbA1c 9.3 ± 1.5% and C-peptide 0.09 ng/ml. 84 T1D patients without MACE were age 42 ± 10.6 years, gender F/M 55/29, duration of diabetes 26.5 ± 10.7 years, BMI 26 ± 5.2(Kg/m2), HbA1c 6.7 ± 2.5 and C-peptide 0.09 ng/ml. There are a total of 584 person-years of follow up to first MACE event and 632 person-years of graft failure, death or last follow-up. Nine patients developed 11 MACE events post-PTA. Therefore, the event rate is 1.5 MACE events per 100 person-years for first MACE event and the total event rate is 1.7 MACE events per 100 person-years of follow-up. Age, smoking (yes), gender, duration of diabetes, HTN and Hyperlipidemia presence did not show any significant impact on post-transplant MACE outcome based on univariate Cox regression but the pre-transplant BMI (HR = 1.14; CI = (1.04, 1.26); p = 0.008) and pre-transplant HbA1c (HR = 1.26; CI = (1.06, 1.51); p = 0.01) showed statistically significant impact. CONCLUSIONS: At our center, MACE is low in PTA recipients. There is no impact of presence of pre-transplant MACE on development of post-transplant MACE but pre-transplant BMI and HbA1c account for risk of MACE.

Background. Graft survival after kidney transplant (KTX) is often estimated by the Kaplan-Meier (KM) method censoring for competing endpoints, primarily death. This method overestimates the incidence of graft loss. Methods. In 3157 adult KTX recipients followed for a mean of 79.2 months, we compared kidney and patient survival probabilities by KM versus competing risk analysis (CRA). These methods are extended to comparing different regression methods. Results. Compared with CRA, the probabilities of death and graft loss (censored for the other outcome) were substantially higher by KM. These differences increased with increasing follow-up time. Importantly, differences in graft losses were magnified in subgroups with greater probabilities of death. Among recipients with diabetes, the probabilities of graft loss at 20 years were 57% by KM and 32% by CRA, while for non-diabetes mellitus corresponding values were 44% and 35%. Similar results are noted when comparing older versus younger recipients. Finally, we find that the Fine-Gray method assumptions are violated when using age and gender as covariates and that the alternative method of Aalen-Johansen may be more appropriate. Conclusions. CRA provides more accurate estimates of long-term graft survival and death, particularly in subgroups of recipients with higher rates of the competing event. Overestimation of risk by KM leads to both quantitative and qualitative misinterpretations of long-term KTX outcomes. When using regression analyses, care should be taken to check assumptions to guide the choice of appropriate method.

AbstractLarge multicenter, randomized controlled trials are the paradigm for determining the efficacy and safety of new therapies. However, applying this classical approach to many areas of transplantation is difficult. For most types of organ transplants, the number of transplants performed is too small for such a trial (lung, pancreas, or vascular composite transplantation are examples). In larger populations such as kidney transplantation, the major unmet needs commonly involve small subsets of patients (antibody‐mediated rejection, recurrent renal disease, etc). This issue is not unique to transplantation and has been successfully overcome in other areas of medicine. In oncology, for example, novel trial designs such as adaptive trial design and master protocols are now relatively common. In addition, the existence of multicenter, ongoing clinical research consortia have greatly enhanced the successful implementation of these novel trial designs. In this manuscript, we examine how novel trial designs, master protocols, and research consortia might enhance studies in transplantation aimed at the regulatory approval of new agents. Our premise is that more efficient approaches to clinical trials already exist and, through a coordinated effort by researchers, the pharmaceutical industry, and regulatory bodies like the FDA, they can be implemented in transplantation.

AbstractKidney paired donation (KPD) and the new kidney allocation system (KAS) in the United States have led to improved transplantation rates for highly sensitized candidates. We aimed to assess the potential need for other approaches to improve the transplantation rate of highly sensitized candidates such as desensitization. Using the UNOS STAR file, we analyzed transplant rates in a prevalent active waiting‐list cohort as of June 1, 2016, followed for 1 year. The overall transplantation rate was 18.9% (11 129/58769). However, only 9.7% (213/2204) of candidates with a calculated panel reactive antibody ≥99.9% received a transplant, and highly sensitized candidates were less likely to receive a living donor transplant. Among candidates with a CPRA ≥ 99.5% (ie. 100%), only 2.5% of transplants were from living donors (13 total, 7 from KPD). Nearly 4 years after KAS (6/30/2018), 1791 actively wait‐listed candidates had a CPRA of ≥99.9% and 34.6% (620/1791) of these had ≥5 years of waiting time. Thus, despite KPD and KAS, many sensitized candidates have not been transplanted even with prolonged waiting time. We conclude that candidates with a CPRA ≥ 99.9% and sensitized candidates with an incompatible living donor and prolonged waiting time may benefit from desensitization to improve their ability to receive a transplant.

AbstractBackgroundCurrent therapy for Type 1 diabetes (T1D) is characterized by significant glucose variability (GV). Pancreas transplantation (PT) is performed in certain T1D patients with and without end‐stage renal disease. To date, GV has been examined to a limited extent after PT.MethodsWe investigated GV using continuous glucose monitoring (CGM) 3‐6 weeks after PT.ResultsEleven patients had simultaneous kidney pancreas transplantation (SPK), nine pancreas after kidney (PAK), and six pancreas transplantation alone (PTA). Mean CGM showed no difference between SPK, 126.5 ± 13.9, PAK 119.9 ± 12.8, and PTA 131.1 ± 29 mg/dL (P value .6). Percentage of time in range (TIR, 70‐180 mg/dL) was 92% for SPK, 93.4% in PAK, and 88.5% in PTA with only 0.3%, 1.5%, and 0.3% of time <70 mg/dL. Percentage >180 mg/dL was 7.9% for SPK, 4.9% PAK, and 11% in PTA. Other measures of GV were similar in the three cohorts. In six patients, CGM was performed before and after PT and improved significantly. GV was also better compared with a matched cohort of T1D patients.ConclusionsAll 3 types of PT resulted in excellent glucose control 3‐6 weeks post‐procedure. CGM outcomes represent an important objective outcome after PT.