BK polyomavirus-pathogen, paradigm and puzzle.

BK virus is a polyomavirus with seroprevalence rates of 80% in adults. Infection is usually acquired during childhood, and the virus is benign or pathologic depending on immune status. The virus reactivates in immunodeficiency states, mostly among transplant (either kidney or bone marrow) recipients. There are approximately 15 000 renal transplants every year in the USA, of which 5-10% develop BK polyomavirus nephropathy; 50-80% of patients who develop nephropathy go on to develop graft failure. BK virus is associated with BK polyomavirus nephropathy, ureteral stenosis, late-onset hemorrhagic cystitis, bladder cancer and other nonlytic large T-expressing carcinomas. The renal spectrum begins with viruria and can end with graft failure. The clinical spectrum and outcomes vary among transplant patients. New noninvasive diagnostic methods, such as urinary polyomavirus Haufen detected by electron microscopy, are currently under study. Treatment is primarily directed at decreasing immunosuppression but may be associated with graft rejection. Repeat transplantation is encouraged as long as viral clearance in plasma prior to transplant is accomplished. There remain no definitive data regarding the utility of transplant nephrectomy.

Recurrent antibody-mediated rejection in renal allograft: physician's dilemma.

Antibody-mediated rejection is the primary cause of renal allograft failure, and the molecular mechanistic is relatively less known in comparison to cell-mediated rejection. With the advent of new immunological agents, the short-term graft survival outcomes have improved, but the long-term outcomes are still unchanged. We present a case of 47-year-old with end-stage renal disease due to presumed lupus status post deceased donor renal transplantation. The patient developed recurrent (a total of five) antibody-mediated rejections (donor-specific antibody and C4d staining negative) spanning within a year of transplant despite the standard of care therapies. The present case draws attention to the importance of non-HLA antibodies in antibody-mediated rejection and diagnostic tools we can rely on when the histology is inconclusive and the role of new immunological agents.

A Model To Estimate Glucose Absorption in Peritoneal Dialysis: A Pilot Study.

Background: Glucose absorption in patients on peritoneal dialysis (PD) may contribute to adverse metabolic effects. Previous studies on glucose absorption were done on patients on continuous ambulatory PD, with a long dwell time. However, the growing majority of contemporary patients on PD perform automated PD with a short dwell time. Moreover, membrane characteristics and dwell time determine small-solute transport across the peritoneal membrane. Methods: In our pilot study, we used data from the peritoneal equilibration test (PET) to develop a model to estimate glucose absorption. In six randomly selected patients on PD, we calculated actual glucose absorption from directly measuring effluent glucose concentration. We then used the R programming language to create a nonlinear, least-squared regression model, inputting PET data, D2/D0, and D4/D0 to generate an exponential decay curve. This model was then used to estimate the fraction of glucose remaining in the dialysate at a particular dwell time t (Dt/D0). Daily glucose absorption was calculated by multiplying 1-Dt/D0 with the amount of glucose the patient was exposed to in 24 hours. Results: We observed the mean glucose absorption (89.7±28.8 g/d), as measured from the effluent, very close to our estimate (88.12±28.9 g/d), and the difference between the glucose estimation and actual absorption was not statistically significant (P>0.05), with "W" value of 8. After validating our hypothesis, we randomly selected an independent cohort of 11 patients with ESKD who were on various PD modalities and analyzed their data. We observed that the mean daily glucose absorption of 62.7±24.5 g (27.98-110.35 g), much lower than that reported in the literature, depends on dwell times and membrane characteristics in addition to the amount of glucose absorption in the cohort. Conclusions: Our model provides a simple tool for estimating glucose absorption and caloric load in contemporary patients on PD. Hopefully, the accurate estimation of caloric load and the incorporation of it into the daily caloric intake of the individual will help to reduce metabolic consequences of hyperglycemia and weight gain and improve overall outcomes of PD.

Lack of Benefit and Potential Harm of Induction Therapy in Simultaneous Liver-Kidney Transplants.

The number of simultaneous liver-kidney transplantations (SLKTs) and use of induction therapy for SLKT have increased recently, without much published evidence, especially in the context of maintenance immunosuppression containing tacrolimus (TAC) and mycophenolic acid (MPA). We queried the Organ Procurement and Transplant Network registry for SLKT recipients maintained on TAC/MPA at discharge in the United States for 2002-2016. The cohort was divided into 3 groups on the basis of induction type: rabbit antithymocyte globulin (r-ATG; n = 831), interleukin 2 receptor antagonist (IL2RA; n = 1558), and no induction (n = 2333). Primary outcomes were posttransplant all-cause mortality and acute rejection rates in kidney and liver allografts at 12 months. Survival rates were analyzed by the Kaplan-Meier method. A propensity score analysis was used to control potential selection bias. Multivariate inverse probability weighted Cox proportional hazard and logistic regression models were used to estimate the hazard ratios (HRs) and odds ratios. Among SLKT recipients, survival estimates at 3 years were lower for recipients receiving r-ATG (P = 0.05). Compared with no induction, the multivariate analyses showed an increased mortality risk with r-ATG (HR, 1.29; 95% confidence interval [CI], 1.10-1.52; P = 0.002) and no difference in acute liver or kidney rejection rates at 12 months across all induction categories. No difference in outcomes was noted with IL2RA induction over the no induction category. In conclusion, there appears to be no survival benefit nor reduction in rejection rates for SLKT recipients who receive induction therapy, and r-ATG appears to increase mortality risk compared with no induction.

Predictors of hyperkalemia and death in patients with cardiac and renal disease.

Predictors of hyperkalemia in patients with cardiovascular disease (CVD; defined as patients with hypertension and heart failure) and associated chronic kidney disease (CKD) are not well established. The aim of this study was to ascertain risk factors of hyperkalemia (defined as serum potassium concentration >5.0 mEq/L) and associated all-cause mortality in patients with CVD treated with antihypertensive drugs that impair potassium homeostasis. In a retrospective analysis using a logistic regression model, risk factors for hyperkalemia and all-cause mortality were analyzed in 15,803 patients with CVD treated with antihypertensive drugs. The mean estimated glomerular filtration rate and mean serum potassium concentration were 55.55 ml/min/1.73 m(2) and 4.06 mEq/L, respectively. Hyperkalemia was observed in 24.5% of study patients and 1.7% of total hospital admissions. Compared to patients with normokalemia, those with hyperkalemia had a higher percentage of death (6.25% vs 2.92%, p = 0.0001) and admissions (7.80% vs 5.04%, p = 0.0001). Predictors of hyperkalemia were CKD stage (odds ratio [OR] 2.14, 95% confidence interval [CI] 2.02 to 2.28), diabetes mellitus (OR 1.59, 95% CI 1.47 to 1.72), coronary artery disease (OR 1.32, 95% CI 1.21 to 1.43), and peripheral vascular disease (OR 1.55, 95% CI 1.36 to 1.77). Predictors of all-cause mortality were CKD stage (OR 1.26, 95% CI 1.12 to 1.43), hyperkalemic event (OR 1.56, 95% CI 1.30 to 1.88), age (OR 1.04, 95% CI 1.03 to 1.05), and hospitalization (OR 1.04, 95% CI 1.04 to 1.05). In conclusion, hyperkalemia is encountered frequently in patients with established CVD who are taking antihypertensive drugs and is associated with increases in all-cause mortality and hospitalizations. Advanced CKD, diabetes mellitus, coronary artery disease, and peripheral vascular disease are independent predictors of hyperkalemia.

Recurrent stress-induced cardiomyopathy: a case report and review article.

ABS is a unique acute cardiac syndrome and a recently recognized form of transient left ventricular dysfunction. It mimics ACS in clinical presentation (chest pain and dyspnea) and specific ECHO findings in the absence of significant coronary lesions. This rare entity accounts for 2.2% of ST segment elevation ACS. Pathophysiology mostly correlates to stress-induced catecholamine release. The syndrome is predominant in females, mostly in the postmenopausal age group. It should be initially managed according to the guidelines of ACS. The prognosis for apical ballooning syndrome is generally favorable with inpatient hospital mortality less than 2%. Reports of a single episode of ABS are common in recent medical literature; we report a rare case of recurrence that provides more insight into the nature of this unique syndrome.