The echocardiographic course of pretransplant pulmonary hypertension following kidney transplantation and associated outcomes.

The post 3 kidney transplant course of pretransplant echocardiographically-defined pulmonary hypertension (PH) was reviewed in 115 patients. Of these 61 patients (the largest cohort reported to date), underwent 160 "for indication" echocardiograms posttransplant (mean echocardiograms per patient: 2.6 ± 2.3). Patients undergoing posttransplant echocardiograms demonstrated greater risks for worse outcomes than those without posttransplant echocardiograms; however, there was no difference in mortality, death-censored graft failure or the composite of death or graft failure between these two groups. Of patients tested, 36 (59%) showed resolution of PH at a median of 37.5 months. Six patients (16.7%) in whom PH resolved (at a median of 29 months), experienced recurrence of PH after an interval of 48 months. No pretransplant demographic or echocardiographic characteristics distinguished those in whom PH persisted versus resolved. Though there was no difference in the risk for mortality or death-censored graft loss between the two groups at 3 and 5 years, there was a higher risk for the composite of mortality or graft loss at three but not at five years in the group with persistent PH. In conclusion, echocardiographically defined PH resolved in 59% of patients following kidney transplantation; but irrespective of resolution there was no clear association with worse outcome.

Defining Vasoplegia Following Durable, Continuous Flow Left Ventricular Assist Device Implantation.

This study aimed to develop a definition of vasoplegia that reliably predicts clinical outcomes. Vasoplegia was evaluated using data from the electronic health record for each 15-minute interval for 72 hours following cardiopulmonary bypass. Standardized definitions considered clinical features (systemic vascular resistance [SVR], mean arterial pressure [MAP], cardiac index [CI], norepinephrine equivalents [NEE]), threshold strategy (criteria occurring in any versus all measurements in an interval), and duration (criteria occurring over multiple consecutive versus separated intervals). Minor vasoplegia was MAP < 60 mm Hg or SVR < 800 dynes⋅sec⋅cm-5 with CI > 2.2 L/min/m2 and NEE ≥ 0.1 µg/kg/min. Major vasoplegia was MAP < 60 mm Hg or SVR < 700 dynes⋅sec⋅cm-5 with CI > 2.5 L/min/m2 and NEE ≥ 0.2 µg/kg/min. The primary outcome was incidence of vasoplegia for eight definitions developed utilizing combinations of these criteria. Secondary outcomes were associations between vasoplegia definitions and three clinical outcomes: time to extubation, time to intensive care unit discharge, and nonfavorable discharge. Minor vasoplegia detected anytime within a 15-minute period (MINOR_ANY_15) predicted the highest incidence of vasoplegia (61%) and was associated with two of three clinical outcomes: 1 day delay to first extubation (95% CI: 0.2 to 2) and 7 day delay to first intensive care unit discharge (95% CI: 1 to 13). The MINOR_ANY_15 definition should be externally validated as an optimal definition of vasoplegia.

Optimization of Acute Kidney Injury (AKI) Time Definitions Using the Electronic Health Record: A First Step in Automating In-Hospital AKI Detection.

Kidney Disease: Improving Global Outcomes (KDIGO) acute kidney injury (AKI) definitions were evaluated for cases detected and their respective outcomes using expanded time windows to 168 h. AKI incidence and outcomes with expanded time intervals were identified in the electronic health records (EHRs) from 126,367 unique adult hospital admissions (2012-2014) and evaluated using multivariable logistic regression with bootstrap sampling. The incidence of AKI detected was 7.4% (n = 9357) using a 24-h time window for both serum creatinine (SCr) criterion 1a (≥0.30 mg/dL) and 1b (≥50%) increases from index SCr, with additional cases of AKI identified: 6963 from 24-48 h.; 2509 for criterion 1b from 48 h to 7 days; 3004 cases (expansion of criterion 1a and 1b from 48 to 168 h). Compared to patients without AKI, adjusted hospital days increased if AKI (criterion 1a and 1b) was observed using a 24-h observation window (5.5 days), 48-h expansion (3.4 days), 48-h to 7-day expansion (6.5 days), and 168-h expansion (3.9 days); all are p < 0.001. Similarly, the adjusted risk of in-hospital death increased if AKI was detected using a 24-h observation window (odds ratio (OR) = 16.9), 48-h expansion (OR = 5.5), 48-h to 7-day expansion (OR = 4.2), and 168-h expansion (OR = 1.6); all are p ≤ 0.01. Expanding the time windows for both AKI SCr criteria 1a and 1b standardizes and facilitates EHR AKI detection, while identifying additional clinically relevant cases of in-hospital AKI.

Incidence, predictors, and survival impact of acute kidney injury in patients with melanoma treated with immune checkpoint inhibitors: a 10-year single-institution analysis.

Background: The incidence of renal immune-related adverse events (irAEs) is reported to be 3.8%, with varied definitions of acute kidney injury (AKI). This study reports a 10-year experience at MD Anderson Cancer Center of patients diagnosed with melanoma and treated with immune checkpoint inhibitors (ICIs) and evaluated the incidence of AKI, associated factors, and its association with overall survival. Methods: A retrospective chart review (2010-2019) of all patients with melanoma treated with ipilimumab, nivolumab, pembrolizumab, or atezolizumab was performed. All available serum creatinine data were extracted and used to calculate the estimated GFR (eGFR) using the CKD Epi equation, and to diagnose AKI using the two KDIGO (Kidney Disease: Improving Global Outcomes) criteria for defining stage I AKI in 1664 unique patients. Cumulative incidence rates of AKI after initiation of ICIs were calculated in the presence of death as a competing risk. The effects of covariates on the cumulative incidence function of AKI were evaluated in a univariant and multivariable analysis. Overall survival was estimated by Kaplan-Meier method in accordance to the occurrence of AKI. Results: The incidence of AKI by definitions 1a and 1b were 3.49% and 3.33%, respectively. After adjudication, AKI attributable to ICI was 58% and 65% of the overall incidence of AKI in each definition respectively. Increasing age was associated with decreased risk of AKI. Asian race was associated with a higher risk of AKI. Comorbidities were not associated with increased risk of AKI while use of proton pump inhibitors (PPI), ipilimumab or ICI combinations were significantly associated with AKI. AKI was not significantly associated with overall survival. Immune-related adverse events (irAEs) occurred in 30% of patients with AKI but their incidence was not different in patients with AKI attributable to ICI versus other AKI. Conclusions: In a large population of patients with melanoma treated with ICIs, an accurate documentation of AKI in setting of ICI use and predictors associated is presented. AKI following ICI use is infrequent, not associated with mortality, and associated with the use of ipilimumab, ICI combinations and PPIs.

Prevalence, Characteristics, and Outcomes of Incidental IgA Glomerular Deposits in Donor Kidneys.

INTRODUCTION: Incidental IgA deposits in donor kidneys have unknown sequelae and may predate clinical kidney disease if primed by adverse immunologic or hemodynamic stimuli or may remain dormant. METHODS: The presence of incidental IgA in post-implantation (T0) biopsies from living (LDK) and deceased donor (DDK) kidneys, and its relationship to post-transplant patient and graft outcomes was investigated in an ethnically diverse US population at a large transplant center. RESULTS: Mesangial IgA was present in 20.4% of 802 T0 biopsies; 13.2% and 24.5% of LDK and DDK, respectively. Donors with incidental IgA deposits were more likely to have hypertension and be of Hispanic or Asian origin. Intensity of IgA staining was 1+ (57.3%), 2+ (26.8%), or 3+ (15.8%) of the T0 IgA+ biopsies. Mesangial pathology correlated with higher-intensity IgA staining with less clearance on follow-up (53.8%) versus 79.2% without mesangial pathology. IgA cleared in 91%, 63%, and 40% of follow-up biopsies with 1+, 2+, and 3+ IgA staining, respectively. Early post-transplant rejection and rejection-related graft loss occurred more frequently in IgA+ kidney recipients; however, 5-year kidney function and graft survival were comparable to kidneys without IgA. CONCLUSION: This first and largest report of incidental IgA in T0 biopsies of LDK and DDK in a US ethnically diverse population demonstrated no adverse association between the presence of IgA in donor kidneys and graft or patient survival. Whether IgA in donor kidneys represents latent IgA nephropathy (IgAN) is uncertain; nevertheless, living donors who demonstrate IgA on T0 biopsy deserve careful follow-up.

The Association of Pretransplant Pulmonary Hypertension With Patient and Graft Survival After Kidney Transplantation: A Retrospective Cohort Study.

BACKGROUND: Pulmonary hypertension (PH) has been well characterized in end-stage kidney disease and carries a grave prognosis. Its relationship to kidney transplantation outcomes is uncertain. The purpose of the present study was to characterize PH in kidney transplant candidates and to evaluate the relationship of PH to post-transplantation outcomes. METHODS: A retrospective review of medical records and echocardiographic findings in all patients listed and transplanted at a large urban academic medical center from 2010 to 2015 was undertaken. PH (defined as echocardiographic evidence of pulmonary artery systolic pressure ≥ 35 mm Hg) was assessed along with demographics, and comorbidities for its relationship to patient, and graft survival by univariable and multivariable analysis. RESULTS: Of 733 patients, 15.6% (115) had PH. PH in this population was primarily due to left ventricular (LV) diastolic dysfunction. Patient survival (78.3% vs 89.6%, P = .02) and the composite of patient and graft survival (70.7% vs 85.0%, P = .04) was reduced at 5 years in patients with PH as compared to patients with No PH, respectively. However, multivariable analysis suggested that age at presentation, race, and left ventricular systolic function but not PH were significantly associated with patient mortality or graft loss. CONCLUSION: Reduced patient and graft survival seen in patients with pulmonary hypertension appears to be related to risk factors other than the pulmonary hypertension itself; therefore, pretransplant PH should not be considered as a barrier to kidney transplantation.

Outcomes of kidney transplantation using deceased donors with history of diabetes.

Deceased diabetic kidneys are increasingly utilized in transplantation. The relationship of donor's history of diabetes to clinical and histological outcomes was examined. Forty-nine diabetic deceased donor kidneys (D-DM) were transplanted into 26 normal (R-N/D-DM) and 23 diabetic recipients (R-DM/D-DM) and compared to 211 diabetic recipients of normal kidneys(R-DM/D-N) and 466 normal recipients of normal kidneys (R-N/D-N). Patient survival at 5 years was 89.7% in R-N/D-N, 96.2% in R-N/D-DM, 80.1% in R-DM/D-N, and a 71.6% in R-DM/D-DM (P = .008). Death-censored graft survival at 5 years was 86.3% in R-N/D-N, 87.4% in R-N/D-DM, 93.5% in R-DM/D-N, and 87.5% in R-DM/D-DM (P = .24). Multivariable regression analysis showed that compared to non-diabetic recipients, diabetic recipients had a 2- to 3-fold increased risk of mortality. In this cohort, there was no impact on death-censored graft survival of diabetic donor status. Only 6 of 26 post-perfusion biopsies showed evidence of diabetic nephropathy (

Chronic kidney disease in patients infected with human immunodeficiency virus (HIV) in an urban cohort.

BACKGROUND AND OBJECTIVES: HIV-infected patients are at risk for developing chronic kidney disease (CKD), defined by estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m2. Our purpose was to understand the genesis of CKD in HIV patients from a large urban clinic in Houston, Texas, USA, and to characterize progression of CKD in the cohort. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: A retrospective cohort study (2012-2016) was conducted in all HIV-infected patients seen in a federally qualified community health center in Houston, Texas. CKD prevalence and its association with HIV viral load and CD4 count were determined. The association of the change in eGFR over time and comorbidities was assessed using linear mixed models. RESULTS: Of 3714 HIV-infected patients analyzed, 153 (4.1%) had CKD. The prevalence of CKD in the different racial groups was 5.4% White, 4.0% African American, 2.8% Hispanic/Latino and 3.2% Asian. There was no difference in the rate of decline in kidney function in White vs. African American HIV infected patients with CKD. Compared with non-CKD patients, CKD patients were older, had lived longer with HIV infection, had lower CD4 cell counts, higher proportions of hypertension, hyperlipidemia, and cerebrovascular disease, and had significantly higher rates of eGFR deterioration represented by a median decrease of 26.5% from first to last follow-up eGFR (versus 0% change). Linear mixed modeling identified older age, male gender, White race, longer time with HIV infection, hypertension, history of kidney stones, cerebrovascular disease, autoimmune disease, increased potassium and total cholesterol levels, and being treated with combination ART as associated with a worsening eGFR over time. CONCLUSION: This study demonstrates a prevalence of CKD in HIV-infected patients of 4.1% and points to an important role for HIV medications and other common comorbidities in the genesis and progression of kidney disease. Importantly, CKD was not more prevalent in African Americans than in Whites, perhaps due to a low prevalence of IV drug abuse as inferred from the lower prevalence of HCV infection in this cohort.

Disparate outcomes observed within Kidney Disease: Improving Global Outcomes (KDIGO) acute kidney injury stage 1.

The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline classifies acute kidney injury (AKI) into 3 stages defined by serum creatinine elevation or urine output decline. We evaluated the potential impact of further categorizing AKI stage 1 into two stages based on serum creatinine criteria, with a focus on how the resulting 4-stage classification would affect the association of AKI stages with clinical outcomes. We defined AKI stage 1a as an absolute increase in serum creatinine of 0.3 mg/dl within 48 hours and stage 1b as a 50% relative increase in serum creatinine within 7 days. We screened all admissions to 5 hospitals from 2012 to 2014 using standardized inclusion and exclusion criteria and included 81,651 admissions in this retrospective cohort study. The incidence of in-hospital AKI was 7.5% for stage 1a, 4.9% for stage 1b, 1.5% for stage 2, and 0.9% for stage 3. Length of stay following the first incidence of AKI was 3.9 days for stage 1a, 6.2 days for stage 1b, 8.8 days for stage 2, and 12.0 days for stage 3. Compared to patients with no AKI, the odds of in-hospital mortality were progressively higher for patients with higher AKI stages (odds ratio 4.3 for patients with stage 1a, 10.9 for stage 1b, 40.6 for stage 2, and 60.0 for stage 3 AKI). Patients with AKI stages 1a and 1b experienced clinically meaningful and statistically significant differences in length of stay and mortality. This study suggests that a modified 4-stage version of the KDIGO AKI classification may provide additional prognostic information.

Cross-sectional evaluation of the relationship between vitamin D status and supplement use across levels of kidney function in adults.

OBJECTIVES: The objective of this study was to assess vitamin D status of US non-pregnant adults using a standardised assay across 15 mL/min/1.73 m2 increments of kidney function, report the use of dietary supplements containing vitamin D and assess relationships between vitamin D and markers of bone resorption. DESIGN: This study is a cross-sectional evaluation. SETTING: The study is from the US National Health and Nutrition Evaluation Survey in 2001-2012. PARTICIPANTS: The participants were non-institutionalised, non-pregnant adults, age ≥20 years. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was serum 25OHD evaluated using liquid chromatography-tandem mass spectroscopy traceable to international reference standards. Secondary outcome measures were use of dietary supplements containing vitamin D and the serum intact parathyroid hormone and bone-specific alkaline phosphatase in a subset of participants. RESULTS: The median 25OHD concentration in 27 543 US non-pregnant adults was 25.7 ng/mL (range, 2.2-150.0 ng/mL). Vitamin D supplements were used by 38.0%; mean (SE)=757 (43) international units/day. The range of 25OHD concentration across groups, stratified by kidney function, was 23.0-28.1 ng/mL. The lowest concentration of 25OHD observed was in people with higher kidney function (23.0 ng/mL for estimated glomerular filtration rate >105 mL/min/1.73 m2). Only 24% of people not taking a dietary supplement had a 25OHD concentration >30 ng/mL. Serum intact parathyroid hormone inversely correlated with 25OHD within all kidney function groups. Bone-specific alkaline phosphatase was also negatively associated with 25OHD concentration. CONCLUSIONS: These data indicate that 25OHD concentrations and supplement use may be suboptimal in a significant proportion of the population, across all kidney function levels. The response of bone resorption markers further suggests that 25OHD levels could be improved. Together, these data support a re-evaluation of the 25OHD concentration associated with health in adults.

Evaluation of Carotid Ultrasonography Screening Among Kidney Transplant Candidates: A Single-Center, Retrospective Study.

BACKGROUND: Kidney transplant candidates undergo rigorous testing prior to clearance for transplantation. Because kidney transplant candidates may be at increased risk for carotid artery stenosis because of arteriosclerosis and atherosclerosis secondary to hypertension, vascular calcification, and diabetes, carotid ultrasound is often performed with the intent of preventing a cerebrovascular accident in the perioperative or posttransplant period. To our knowledge, there has not been a study investigating the utility of screening carotid ultrasonography in pretransplant candidates. The purpose of the present study was to investigate the yield of carotid ultrasonography in end-stage renal disease patients, at high risk for having clinically significant vascular disease evaluated at our center for kidney transplantation during the years 2009 to 2014. METHODS: Data for carotid ultrasound findings and risk factors for carotid artery disease were extracted from the medical records. RESULTS: A total of 882 patients were included in our study of which only 13 patients (1.47% of the cohort) had significant carotid artery stenosis (>70%) on ultrasound testing. Using multiple logistic regression on the outcome of carotid stenosis, congestive heart failure (adjusted odds ratio, 5.2), and peripheral vascular disease (adjusted odds ratio, 4.4) were positively associated with carotid stenosis. CONCLUSIONS: The prevalence of significant carotid artery stenosis was only 1.47% in our cohort of kidney transplant candidates, and the routine use of carotid ultrasound testing in this population may not be an efficient use of clinical resources. Use of risk factors, such as congestive heart failure or peripheral vascular disease, may identify patients who are more likely to benefit from carotid ultrasonography screening.

Disparate rates of acute rejection and donor-specific antibodies among high-immunologic risk renal transplant subgroups receiving antithymocyte globulin induction.

Lymphocyte-depleting induction lowers acute rejection (AR) rates among high-immunologic risk (HIR) renal transplant recipients, including African Americans (AAs), retransplants, and the sensitized. It is unclear whether different HIR subgroups experience similarly low rates of AR. We aimed to describe the incidence of AR and de novo donor-specific antibody (dnDSA) among HIR recipients categorized by age, race, or donor type. All received antithymocyte globulin (ATG) induction and triple maintenance immunosuppression. A total of 464 HIR recipients from 2007 to 2014 were reviewed. AR and dnDSA rates at 1 year for the entire population were 14% and 27%, respectively. AR ranged from 6.7% among living donor (LD) recipients to 30% in younger AA deceased donor (DD) recipients. De novo donor-specific antibody at 1 year ranged from 7% in older non-AA LD recipients to 32% in AAs. AA race remained as an independent risk factor for AR among DD recipients and for dnDSA among all HIR recipients. Development of both AR and dnDSA within the first year was associated with a 54% graft survival at 5 years and was an independent risk factor for graft loss. Despite utilization of recommended immunosuppression for HIR recipients, substantial disparities exist among subgroups, warranting further consideration of individualized immunosuppression in certain HIR subgroups.

Phosphorus Regulation in Chronic Kidney Disease.

Serum phosphorus levels stay relatively constant through the influence of multiple factors-such as parathyroid hormone, fibroblast growth factor 23, and vitamin D-on the kidney, bone, and digestive system. Whereas normal serum phosphorus ranges between 3 mg/dL to 4.5 mg/dL, large cross-sectional studies have shown that even people with normal kidney function are sometimes found to have levels ranging between 1.6 mg/dL and 6.2 mg/dL. While this may partially be due to diet and the factors mentioned above, total understanding of these atypical ranges of serum phosphorus remains uncertain. Risks for bone disease are high in people aged 50 and older, and this group comprises a large proportion of people who also have chronic kidney disease. Consuming diets low in calcium and high in phosphorus, especially foods with phosphate additives, further exacerbates bone turnover. Existing bone disease increases the risk for high serum phosphorus, and higher serum phosphorus has been associated with increased adverse events and cardiovascular-related mortality both in people with chronic kidney disease and in those with no evidence of disease. Once kidney function has deteriorated to end-stage disease (Stage 5), maintaining normal serum phosphorus requires dietary restrictions, phosphate-binding medications, and dialysis. Even so, normal serum phosphorus remains elusive in many patients with Stage 5 kidney disease, and researchers are testing novel targets that may inhibit intestinal transport of phosphorus to achieve better phosphate control. Protecting and monitoring bone health should also aid in controlling serum phosphorus as kidney disease advances.

Association of dietary phosphate and serum phosphorus concentration by levels of kidney function.

BACKGROUND: The health implications of dietary phosphorus intake and the role of kidney function in managing serum phosphorus homeostasis are well studied. However, examining the source of dietary phosphorus intake and its impact on serum phosphorus has not been characterized in population studies. OBJECTIVE: This study aimed to distinguish the association of food sources of organic phosphorus and inorganic phosphate additives with serum phosphorus concentration. DESIGN: A cross-sectional analysis of 24-h food recall data from 7895 adult participants in the National Health and Nutrition Examination Survey 2003-2006 was performed. Phosphorus content of foods was categorized as organic or inorganic. Correlations of serum phosphorus to clinical and dietary intake variables were achieved by using multiple regression analysis. RESULTS: After controlling for estimated glomerular filtration rate (eGFR), body mass index (BMI; in kg/m²), and albumin-to-creatinine ratio, a significant increase in serum phosphorus occurred with dairy foods with inorganic phosphates [parameter estimate (PE) ± SE: 0.07 ± 0.02 mg/dL, P < 0.01] or without inorganic phosphates (PE: 0.02 ± 0.01, P < 0.001) and cereals/grains with inorganic phosphates (PE: 0.005 ± 0.002, P < 0.01). Significantly higher serum phosphorus occurred when eGRF was <30 (PE: 0.24 ± 0.08, P < 0.0001), but eGFR 30-44 (PE: -0.11 ± 0.04, P < 0.01) and 45-60 (PE: -0.10 ± 0.04, P < 0.01) were associated with lower serum phosphorus; higher serum phosphorus was associated with BMI <18.5 (PE: 0.18 ± 0.05, P = 0.0009) but lower with BMI ≥35-39 (PE: -0.09 ± 0.03, P = 0.0013) or ≥40 (PE: -0.10 ± 0.03, P = 0.014). CONCLUSIONS: This analysis shows that dairy products and cereals/grains having inorganic phosphate additives significantly increase serum phosphorus concentration, despite being consumed less frequently than foods without phosphate additives. It seems prudent for the Nutrient Facts Label to include phosphorus but also for food manufacturers to consider alternatives to phosphate additives.

Treatment of acute tacrolimus toxicity with phenytoin in solid organ transplant recipients.

The pharmacokinetics of tacrolimus are influenced by many factors, including genetic variability, acute infections, liver dysfunction, and interacting medications, which can result in elevated concentrations. The most appropriate management of acute tacrolimus toxicity has not been defined though case reports exist describing the therapeutic use of enzyme inducers to increase tacrolimus metabolism and decrease concentrations. We are reporting on the utilization of phenytoin to assist in decreasing tacrolimus concentrations in a case series of four solid organ transplant recipients with acute, symptomatic tacrolimus toxicity presenting with elevated serum creatinine, potassium, and tacrolimus trough concentrations greater than 30 ng/mL. All four patients had the potential causative agents stopped or temporarily held and were given 300 to 400 mg/day of phenytoin for two to three days. Within three days of beginning phenytoin, all four patients had a decrease in tacrolimus concentration to less than 15 ng/mL, a return to or near baseline creatinine concentration, and lack of phenytoin-related side effects. Therefore, phenytoin appears to be a safe and potentially beneficial treatment option in patients with symptomatic tacrolimus toxicity.

Gastrointestinal phosphate handling in CKD and its association with cardiovascular disease.

Increases in serum concentrations of parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) and ultimately phosphate and decreases in 1,25-dihydroxyvitamin D level are thought to play a central role in the progressive nature of kidney disease and the development of cardiovascular disease in patients with chronic kidney disease. The initial changes in PTH and FGF-23 levels are adaptive to maintain serum phosphate concentration and phosphate load within defined levels by increasing urinary excretion of phosphate. Less well appreciated is the unanticipated finding that absorption of phosphate from the gastrointestinal tract is not downregulated in chronic kidney disease. This maladaptive response maintains higher levels of phosphate absorption, thereby contributing to the phosphate burden. Moreover, in response to a low-phosphate diet, as often is prescribed to such patients, gut phosphate absorption may be enhanced, undermining the potential beneficial effects of this intervention. Given the poor response to limiting phosphate intake and the use of phosphate binders, we suggest that research efforts be oriented toward better understanding of the factors that affect phosphate absorption in the gastrointestinal tract and the development of agents that directly inhibit phosphate transporters in the small intestine and/or their associated binding proteins.

Cross-sectional and case-control analyses of the association of kidney function staging with adverse postoperative outcomes in general and vascular surgery.

OBJECTIVE: This study aimed to assess kidney dysfunction in general surgical patients and examine the effect on postoperative mortality and morbidity. BACKGROUND: An estimated 13% of the US population has chronic kidney disease (CKD), but awareness among patients and caregivers is lacking. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data sets for 2005-2007 were analyzed. Preoperative kidney function was assessed by the Modification of Diet in Renal Disease formula for estimated glomerular filtration rate (eGFR) and staged according to National Kidney Foundation. Cross-sectional analyses were performed for 30-day mortality (Cox proportional hazard) and incidence of major complications (nominal logistic regression). A case-control cohort of colectomy cases was analyzed comparing patients in the stage 4 CKD group and the no CKD group (no-CKD). RESULTS: Sixty-four percent of evaluable patients had reduced eGFR, but eGFR was not evaluable in 28% of the surgical cases. In the 260,352 evaluable cases, adjusted hazard ratio for 30-day mortality was 2.30 [95% confidence interval (CI), 2.11-2.51] for stage 3 CKD; 3.37 (95% CI, 3.01-3.76) for stage 4 CKD; and 3.05 (95% CI, 2.68-3.47) for stage 5 CKD compared with no-CKD (P < 0.0001). CKD was an independent risk factor for having major complications postsurgery [stage 3, odds ratio (OR) = 1.24 (95% CI, 1.19-1.29); stage 4, OR = 1.65 (95% CI, 1.52-1.78); and stage 5 CKD, OR = 1.40 (95% CI, 1.30-1.51); P < 0.0001]. The case-control for colectomy was confirmatory: increased 30-day mortality in stage 4 CKD versus no-CKD (hazard ratio = 2.58, 95% CI, 1.13-5.92; P = 0.025). CONCLUSIONS: Renal insufficiency may be underrecognized in the general and vascular (noncardiac) surgery population, is a leading independent predictor of poor early postoperative outcomes, and should be routinely assessed in the preoperative setting.

Donor-specific HLA-DQ antibodies may contribute to poor graft outcome after renal transplantation.

Increasing evidence suggests a detrimental effect of donor-specific antibodies directed against the human leukocyte antigen (HLA)-A, -B, and -DR loci on renal allograft outcomes. Limited data exist on the impact of de novo HLA-DQ antibodies. Over a 3-year period, we prospectively monitored 347 renal transplant recipients without pre-transplant donor-specific antibodies for their development de novo. After 26 months of follow-up, 62 patients developed donor-specific antibodies, of which 48 had a HLA-DQ antibody either alone (33 patients) or in combination with an HLA-A, -B, or -DR antibody (15 patients). Only 14 patients developed a donor-specific HLA-A, -B, or -DR antibody without a HLA-DQ antibody present. Acute rejection occurred in 21% of the HLA-DQ-only patients, insignificant when compared with 11% of patients without donor-specific antibodies. At the last follow-up, the mean serum creatinine and the fraction of patients with proteinuria were significantly higher in those that developed only HLA-DQ than those without antibodies. The 3-year graft survival was significantly worse when HLA-DQ antibodies were combined with non-DQ antibodies (52%) compared with HLA-DQ alone, non-DQ antibodies alone, or no antibodies (92-94%). Thus, our prospective monitoring study found that donor-specific HLA-DQ antibodies were the most common type detected and these antibodies may contribute to inferior graft outcomes. Ongoing surveillance is necessary to determine the long-term outcome of patients developing HLA-DQ donor-specific antibodies.

Initial survival data of kidney transplant patients with pre-transplant monoclonal gammopathy.

BACKGROUND: Monoclonal gammopathy of undetermined significance (MGUS) is the presence of a serum monoclonal protein at a concentration of <3 g/dL without evidence of lymphoproliferative disease or organ damage. The prevalence of MGUS in kidney transplantation (KT) candidates is unknown. The present is a retrospective report of patients who underwent evaluation for a KT and were found to have MGUS at our center. METHODS: All transplant candidates found to have MGUS between the years 2000 and 2007 were included. Variables were collected. Patients with MGUS that received a KT were compared with patients with MGUS that were not transplanted. RESULTS: Of a total of 1215 KT candidates, 34 were found to have MGUS during the KT evaluation. Nine patients with MGUS were transplanted. Myeloma or lymphoproliferative disease was not observed. Following transplantation, the MGUS group had a lower survival than the non-transplanted group. However, survival from the time of MGUS diagnosis was not different between the transplanted and non-transplanted MGUS groups. CONCLUSIONS: In this group, transplantation did not confer a survival benefit. It is our hope that these initial data will serve as a platform for future studies. We suggest MGUS screening in all patients older than 50 yr of age undergoing evaluation for transplantation.