Papers by Brittany Shelton
<jats:p>General surgeons are encountering an increasing number of cases involving immunosup... more <jats:p>General surgeons are encountering an increasing number of cases involving immunosuppressed patients due to a number of factors, including the improvement in treatment for HIV, increased survival following solid-organ transplantation, and more aggressive chemotherapy. These groups of patients present unique challenges for the surgeon and often require more comprehensive preoperative assessment and perioperative monitoring. This review addresses the surgical management of these immunocompromised populations, with specific recommendations for each type of patient. Tables outline opportunistic infections and antibiotic prophylaxis; common immunosuppressive medications, posttransplantation drug levels, and side effects for renal transplant recipients; components of preoperative workup involving suspected infection in immunocompromised patients; and anesthetics and demonstrated impact on immune response and cancer recurrence. Graphs display the number of AIDS diagnoses and deaths and people living with AIDS and HIV in the United States over time, and compare percentages of death certificates reporting opportunistic infection versus chronic disease in the HIV-infected population. Management algorithms outline approaches to patients with defects in host defenses and candidates for transplantation to be deliberately immunosuppressed. This review contains 2 graphs, 2 management algorithms, 4 tables, 157 references, and 5 annotated key references.</jats:p>
DeckerMed Surgery, Jul 1, 2015
<jats:p>General surgeons are encountering an increasing number of cases involving immunosup... more <jats:p>General surgeons are encountering an increasing number of cases involving immunosuppressed patients due to a number of factors, including the improvement in treatment for HIV, increased survival following solid-organ transplantation, and more aggressive chemotherapy. These groups of patients present unique challenges for the surgeon and often require more comprehensive preoperative assessment and perioperative monitoring. This review addresses the surgical management of these immunocompromised populations, with specific recommendations for each type of patient. Tables outline opportunistic infections and antibiotic prophylaxis; common immunosuppressive medications, posttransplantation drug levels, and side effects for renal transplant recipients; components of preoperative workup involving suspected infection in immunocompromised patients; and anesthetics and demonstrated impact on immune response and cancer recurrence. Graphs display the number of AIDS diagnoses and deaths and people living with AIDS and HIV in the United States over time, and compare percentages of death certificates reporting opportunistic infection versus chronic disease in the HIV-infected population. Management algorithms outline approaches to patients with defects in host defenses and candidates for transplantation to be deliberately immunosuppressed. This review contains 2 graphs, 2 management algorithms, 4 tables, 157 references, and 5 annotated key references.</jats:p>
Circulation, 2018
Background: Obesity has become a national epidemic, and is associated with increased risk for com... more Background: Obesity has become a national epidemic, and is associated with increased risk for comorbid diseases including end-stage renal disease (ESRD). Among ESRD patients, obesity may improve dialysis-survival but decreases likelihood of transplantation, and as such, obesity prevalence may directly impact growth of the incident dialysis population. Methods: Incident adult ESRD patients with complete body mass index (BMI, kg/m 2 ) data were identified from the United States Renal Data System from 01/01/1995-12/31/2010 (n=1,822,598). Data from the Behavioral Risk Factor Surveillance System of the Centers for Disease Control and Prevention (n=4,303,471) represented the US population when weighted. Trends in BMI and obesity classes I (BMI of 30-34.9), II (BMI of 35-39.9), and III (BMI ≥40) were examined by year of dialysis initiation. Trends in median BMI slope were compared between the ESRD and US populations using linear regression. Results: Median BMI of ESRD patients in 1995 was ...
JAMA Surgery, 2021
Importance Living donor kidney transplant (LDKT) is the ideal treatment for end-stage kidney dise... more Importance Living donor kidney transplant (LDKT) is the ideal treatment for end-stage kidney disease, but racial disparities in LDKT have increased over the last 2 decades. Recipient clinical and social factors do not account for LDKT racial inequities, although comprehensive measures of community-level vulnerability have not been assessed. Objective To determine if racial disparities persist in LDKT independent of community-level vulnerability. Design, Setting, and Participants This retrospective, multicenter, cross-sectional study included data from 19 287 adult kidney-only transplant recipients in the Scientific Registry of Transplant Recipients. The study included individuals who underwent transplant between January 1 and December 31, 2018. Exposures Recipient race and the 2018 US Centers for Disease Control and Prevention Social Vulnerability Index (SVI). Census tract-level SVI data were linked to census tracts within each recipient zip code. The median SVI measure among the census tracts within a zip code was used to describe community-level vulnerability. Main Outcomes and Measures Kidney transplant donor type (deceased vs living). Modified Poisson regression was used to evaluate the association between SVI and LDKT, and to estimate LDKT likelihood among races, independent of community-level vulnerability and recipient-level characteristics. Results Among 19 287 kidney transplant recipients, 6080 (32%) received LDKT. A total of 11 582 (60%) were male, and the median (interquartile range) age was 54 (43-63) years. There were 760 Black LDKT recipients (13%), 4865 White LDKT recipients (80%), and 455 LDKT recipients of other races (7%; American Indian, Asian, multiracial, and Pacific Islander). Recipients who lived in communities with higher SVI (ie, more vulnerable) had lower likelihood of LDKT compared with recipients who lived in communities with lower SVI (ie, less vulnerable) (adjusted relative risk [aRR], 0.97; 95% CI, 0.96-0.98; P < .001). Independent of community-level vulnerability, compared with White recipients, Black recipients had 37% lower likelihood (aRR, 0.63; 95% CI, 0.59-0.67; P < .001) and recipients of other races had 24% lower likelihood (aRR, 0.76; 95% CI, 0.70-0.82; P < .001) of LDKT. The interaction between SVI and race was significant among Black recipients, such that the disparity in LDKT between Black and White recipients increased with greater community-level vulnerability (ratio of aRRs, 0.67; 95% CI, 0.51-0.87; P = .003). Conclusions and Relevance Community-level vulnerability is associated with access to LDKT but only partially explains LDKT racial disparities. The adverse effects of living in more vulnerable communities were worse for Black recipients. The interaction of these constructs is worrisome and suggests evaluation of other health system factors that may contribute to LDKT racial disparities is needed.
Clinical Transplantation, 2021
Non‐alcoholic steatohepatitis has emerged as a leading cause of cirrhosis, and obesity‐associated... more Non‐alcoholic steatohepatitis has emerged as a leading cause of cirrhosis, and obesity‐associated comorbidities, including renal disease, have increased in prevalence. Obesity predisposes the kidney to hyperfiltration injury, potentially impairing acute kidney injury recovery. Identification of patients at risk for renal dysfunction is impeded by poor performance of renal function estimating equations among cirrhotics. To better understand obesity among cirrhotics and renal disease progression, we examined likelihood of kidney transplantation (KT) waitlisting after liver transplant alone (LTA) by obesity class.
Transplantation, 2018
Introduction: Obesity prevalence among children in the United States (US) is high, but the rate o... more Introduction: Obesity prevalence among children in the United States (US) is high, but the rate of increase has slowed over time. Among pediatric endstage renal disease (ESRD) patients, poor appetite and delayed growth are common, and it is unknown if the pediatric ESRD population mirrors the obesity epidemic observed in the general US pediatric population. Materials and Methods: Incident pediatric ESRD patients with complete body mass index (BMI, kg/m2) data were identified from the United States Renal Data System from 01/01/1999-12/31/2012 (n=9,046). Data from the National Health and Nutrition Examination Survey represented the pediatric US population when weighted. All BMI values were age and sex standardized to BMI z scores using the CDC standards for United States children. BMI z scores were used to define obesity. Trends in BMI and obesity were examined by year of dialysis initiation. Trends in BMI slope were compared between the ESRD and US pediatric populations using linear regression.
Transplantation, 2018
Improvement of photosynthetic traits is a promising strategy to break the yield potential barrier... more Improvement of photosynthetic traits is a promising strategy to break the yield potential barrier of major food crops. Leaf photosynthetic traits were evaluated in a set of high yielding Oryza sativa, cv. Swarna 9 Oryza nivara backcross introgression lines (BILs) along with recurrent parent Swarna, both in wet (Kharif) and dry (Rabi) seasons in normal irrigated field conditions. Net photosynthesis (P N) ranged from 15.37 to 23.25 lmol (CO 2) m-2 s-1 in the BILs. Significant difference in P N was observed across the seasons and genotypes. Six BILs
Clinical Transplantation, 2018
Background: Despite a survival benefit from transplantation and acceptable outcomes, patients wit... more Background: Despite a survival benefit from transplantation and acceptable outcomes, patients with human immunodeficiency virus (HIV+) face barriers to kidney transplantation. Little is known about the acceptance or decline of organ offers on their behalf because wait-list registry data do not include HIV serostatus. Methods: We performed a retrospective cohort study using match-run data from the Organ Procurement and Transplantation Network, including every kidney offer from May 1, 2007 to July 3, 2013. HIV and hepatitis C virus (HCV) serostatus were obtained by merging the match-run with clinical data from a large dialysis provider. We used Cox proportional hazards modeling to evaluate differences in time to the first organ offer and to transplantation. 35,646 uninfected, 2,213 HCV+, 418 HIV+, and 71 HIV+/HCV+ candidates received organ offers during the study period. Results: Compared to uninfected candidates, HIV+ candidates had a significantly lower likelihood of receiving a first offer (adjusted hazard ratio [aHR] 0.88, 95% confidence interval [CI] 0.79-0.99) and undergoing transplantation (aHR 0.82, 95% CI 0.68-0.98) after receiving a first offer; HCV+ candidates had a similar likelihood of receiving a first offer (aHR 0.98, 95% CI 0.92-1.03) and greater likelihood of transplantation after receiving a first offer (aHR 1.23, 95% CI 1.12-1.36). Conclusions: HIV+ candidates had a significantly longer wait until their first organ offer and to transplantation. Efforts to increase their access to transplantation are needed.
Annals of surgery, Jan 17, 2018
To examine the largest single-center experience of simultaneous kidney/pancreas transplantation (... more To examine the largest single-center experience of simultaneous kidney/pancreas transplantation (SPK) transplantation among African-Americans (AAs). Current dogma suggests that AAs have worse survival following SPK than white recipients. We hypothesize that this national trend may not be ubiquitous. From August 30, 1999, through October 1, 2014, 188 SPK transplants were performed at the University of Alabama at Birmingham (UAB) and 5523 were performed at other US centers. Using Kaplan-Meier survival estimates and Cox proportional hazards regression, we examined the influence of recipient ethnicity on survival. AAs comprised 36.2% of the UAB cohort compared with only 19.1% nationally (P < 0.01); yet, overall, 3-year graft survival was statistically higher among UAB than US cohort (kidney: 91.5% vs 87.9%, P = 0.11; pancreas: 87.4% vs 81.3%; P = 0.04, respectively) and persisted on adjusted analyses [kidney adjusted hazard ratio (aHR): 0.58, 95% confidence interval (95% CI) 0.35-0.9...
Clinical Kidney Journal, 2017
Background: Hepatitis C virus (HCV) infection is common in dialysis patients and renal transplant... more Background: Hepatitis C virus (HCV) infection is common in dialysis patients and renal transplant recipients and has been associated with diminished patient and allograft survival. HCV-positive (HCVþ) kidneys have been used in HCV-positive (HCVþ) recipients as a means of facilitating transplantation and expanding the organ donor pool; however, the effect of donor HCV serostatus in the modern era is unknown. Methods: Using national transplant registry data, we created a propensity score-matched cohort of HCVþ recipients who received HCV-positive donor kidneys compared to those transplanted with HCV-negative kidneys. Results: Transplantation with an HCVþ kidney was associated with an increased risk of death {hazard ratio [HR] 1.43 [95% confidence interval (CI) 1.18-1.76]; P < 0.001} and allograft loss [HR 1.39 (95% CI 1.16-1.67); P < 0.001] compared with their propensity score-matched counterparts. However, HCVþ kidneys were not associated with an increased risk of acute rejection [odds ratio 1.16 (95% CI 0.84-1.61); P ¼ 0.35]. Conclusions: While use of HCVþ donor kidneys can shorten the wait for renal transplantation and maximize organ utility for all candidates on the waiting list, potential recipients should be counseled about the increased risks associated with HCVþ kidney.
Clinical journal of the American Society of Nephrology : CJASN, Jan 7, 2017
Kidney transplantation among HIV-infected patients with ESRD confers a significant survival benef... more Kidney transplantation among HIV-infected patients with ESRD confers a significant survival benefit over remaining on dialysis. Given the high mortality burden associated with dialysis, understanding access to kidney transplantation after waitlisting among HIV+ candidates is warranted. Data from the Scientific Registry of Transplant Recipients were linked to Intercontinental Marketing Statistics pharmacy fills (January 1, 2001 to October 1, 2012) so that we could identify and study 1636 HIV+ (defined as having filled one or more antiretroviral medications unique to HIV treatment) and 72,297 HIV- kidney transplantation candidates. HIV+ waiting list candidates were more often young (<50 years old: 62.7% versus 37.6%; P<0.001), were more often men (75.2% versus 59.3%; P<0.001), were more often black (73.6% versus 27.9%; P<0.001), had longer time on dialysis (years: 2.5 versus 0.8; P<0.001), were more often coinfected with hepatitis C virus (9.0% versus 3.9%; P<0.001),...
Annals of surgery, Jan 9, 2017
The aim of this study was to develop a novel chronic kidney disease (CKD) risk prediction tool fo... more The aim of this study was to develop a novel chronic kidney disease (CKD) risk prediction tool for young potential living kidney donors. Living kidney donor selection practices have evolved from examining individual risk factors to a risk calculator incorporating multiple characteristics. Owing to limited long-term data and lack of genetic information, current risk tools lack precision among young potential living kidney donors, particularly African Americans (AAs). We identified a cohort of young adults (18-30 years) with no absolute contraindication to kidney donation from the longitudinal cohort study Coronary Artery Risk Development in Young Adults. Risk associations for CKD (estimated glomerular filtration rate <60 mL/min/1.73 m) were identified and assigned weighted points to calculate risk scores. A total of 3438 healthy adults were identified [mean age 24.8 years; 48.3% AA; median follow-up 24.9 years (interquartile range: 24.5-25.2)]. For 18-year olds, 25-year projected ...
American Journal of Transplantation, 2016
For some patient subgroups, HIV-infection has been associated with worse outcomes after kidney tr... more For some patient subgroups, HIV-infection has been associated with worse outcomes after kidney transplantation (KT); potentially modifiable factors may be responsible. The study goal was to identify factors that predict a higher risk of graft loss among HIV+ KT recipients compared with a similar transplant among HIV− recipients. 82,762 deceased donor KT (HIV+: 526; HIV−: 82,236) reported to SRTR (2001-2013) were studied by interaction term analysis. Compared to HIV− recipients, HCV amplified risk 2.72-fold among HIV+ KT recipients (aHR: 2.72, 95%CI: 1.75-4.22, p<0.001); and 43% of the excess risk was attributable to the interaction between HIV and HCV (AP: 0.43, 95%CI: 0.23-0.63, p=0.02). Among HIV+ recipients with >3 HLA mismatches (MM), risk was amplified 1.80-fold compared to HIV− (aHR: 1.80, 95% CI: 1.31-2.47, p < 0.001); and 42% of the excess risk was attributable to the interaction between HIV and >3 HLA MM (AP: 0.42, 95%CI: 0.24-0.60, p=0.01). High-HIV-risk (HIV+/HCV+ & >3 HLA MM) recipients had a 3.86-fold increased risk compared to low-HIV-risk (HIV+/HCV− & ≤3 HLA MM) recipients (aHR: 3.86, 95%CI: 2.37-6.30, p< 0.001). Avoidance of >3 HLA mismatches in HIV+ KT recipients, particularly among co-infected patients, may mitigate the increased risk of graft loss associated with HIV-infection.
American Journal of Transplantation, 2013
Obese patients have a decreased risk of death on dialysis but an increased risk of death after tr... more Obese patients have a decreased risk of death on dialysis but an increased risk of death after transplantation, and may derive a lower survival benefit from transplantation. Using data from the United States between 1995 and 2007 and multivariate non-proportional hazards analyses we determined the relative risk of death in transplant recipients grouped by body mass index (BMI) compared to wait-listed candidates with the same BMI (n ¼ 208 498). One year after transplantation the survival benefit of transplantation varied by BMI: Standard criteria donor transplantation was associated with a 48% reduction in the risk of death in patients with BMI ! 40 kg/m 2 but a !66% reduction in patients with BMI < 40 kg/m 2. Living donor transplantation was associated with !66% reduction in the risk of death in all BMI groups. In subgroup analyses, transplantation from any donor source was associated with a survival benefit in obese patients !50 years, and diabetic patients, but a survival benefit was not demonstrated in Black patients with BMI ! 40 kg/m 2. Although most obese patients selected for transplantation derive a survival benefit, the benefit is lower when BMI is !40 kg/m 2 , and uncertain in Black patients with BMI ! 40 kg/m 2 .
Journal of the American College of Surgeons
INTRODUCTION: Despite the value of ACS-NSQIP, 30-day outcomes abstraction remains laborious. We a... more INTRODUCTION: Despite the value of ACS-NSQIP, 30-day outcomes abstraction remains laborious. We applied supervised machine learning algorithms, previously developed for surgical site infection (SSI) detection from electronic health record structured clinical data and unstructured documents through natural language processing (NLP) at a single institution for semi-automated overall and organ-space SSI abstraction. METHODS: A Lasso-penalized logistic regression model was trained on 2011 to 2013 data. Training dataset performance with 10-fold cross-validation and thresholds stratifying patients into "negative", "positive", and "possible" SSI tiers were established. Algorithms were separately evaluated on 2014 data overall and by tier. RESULTS: With 2011 to 2013 data as training (n ¼ 6,188) and 2014 as evaluation (n ¼ 2,750), algorithms had good performance (Table). "Negative" and "positive" overall and organ-space SSI tiers had <1% false-negatives and 6 and 4 false-positives, respectively. Given high predictive "positive" and "negative" tier performance, manual extraction is primarily required for the "possible" tier, with 153 and 40 "possible" overall and organ-space SSIs corresponding to decreased abstraction by 94% and 98%. Blinded review of the "possible" tier, considering only the features selected by the algorithm, resulted in high agreement with the surgical clinical reviewer's (SCR) assessment based on full chart abstraction, pointing toward additional efficiency. CONCLUSIONS: Semi-automated SSI detection greatly accelerates manual abstraction. This could be translated to other postoperative outcomes and reduce cost barriers for wider ACS-NSQIP adoption.
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Papers by Brittany Shelton