Kremers, Walter K

Non‐invasive tests to identify age and early disease‐associated pathology within the kidney are needed. Specific populations of urinary extracellular vesicles (EVs) could potentially be used for such a diagnostic test. Random urine samples were obtained from age‐ and sex‐stratified living kidney donors before kidney donation. A biopsy of the donor kidney was obtained at the time of transplantation to identify nephron hypertrophy (larger glomerular volume, cortex per glomerulus and mean profile tubular area) and nephrosclerosis (% fibrosis, % glomerulosclerosis and arteriosclerosis). Renal parenchymal‐derived EVs in cell‐free urine were quantified by digital flow cytometry. The relationship between these EV populations and structural pathology on the kidney biopsy was assessed. Clinical characteristics of the kidney donors (n=138, age range: 20–70 years, 50% women) were within the normative range. Overall, urine from women contained more EVs than that from men. The number of exosomes, juxtaglomerular cells and podocyte marker–positive EVs decreased (p<0.05) with increasing age. There were fewer total EVs as well as EVs positive for mesangial cell, parietal cell, descending limb of Henle's loop (simple squamous epithelium), collecting tubule‐intercalated cell and monocyte chemoattractant protein‐1 markers (p<0.05) in persons with nephron hypertrophy. The number of EVs positive for intercellular adhesion molecule‐1, juxtaglomerular cell, podocyte, parietal cell, proximal tubular epithelial cell, distal tubular epithelial cell and collecting duct cells were fewer (p<0.05) in persons with nephrosclerosis. EVs carrying markers of cells from the renal pelvis epithelium did not associate with any indices of nephron hypertrophy or nephrosclerosis. Therefore, specific populations of EVs derived from cells of the glomerulus and nephron associate with underlying kidney structural changes. Further validation of these findings in other cohorts is needed to determine their clinical utility.

AbstractBackgroundThe duration of anticytomegalovirus (CMV) prophylaxis after lung transplantation (LT) varies among transplant centers.MethodsA retrospective review of CMV donor‐seropositive/recipient‐seronegative (D+/R−) and CMV recipient‐seropositive (R+) LT patients between January 2005 and September 2012 was performed. Starting January 2007, valganciclovir prophylaxis was given for at least 12 months (often lifelong) for CMV D+/R− and extended from three to six months for R+ LT patients. Risks of CMV infection and CMV disease, and mortality after LT, were assessed.ResultsA total of 88 LT patients were studied, including 32 CMV D+/R−, and 56 R+ patients. During the follow‐up period, 11 (12.5%) patients had asymptomatic CMV infection, and nine (10.3%) developed CMV disease. CMV disease (HR, 4.189; 95% CI: 1.672–10.495; p = 0.002) and CMV infection and disease (HR, 3.775; 95% CI: 1.729–8.240; p = 0.001) were significant risk factors for mortality. Overall, no significant difference was observed in rates of CMV infection or disease among LT recipients who received shorter vs. extended CMV prophylaxis.ConclusionsDespite extended prophylaxis, LT patients remain at risk of CMV infection and disease. CMV remains associated with increased mortality after transplantation.

Abstract Background Frailty in non‐transplant populations increases morbidity and mortality. Muscle wasting is an important frailty characteristic. Low body mass index is used to measure wasting, but can over‐ or underestimate muscle mass. Computed tomography ( CT ) software can directly measure muscle mass. It is unknown if muscle wasting is important in lung transplantation. Aim and Methods The aim of this single‐center, retrospective cohort study was to determine whether pre‐transplant low muscle mass (as measured by CT using Slice‐O‐matic software at L2–L3 interspace) was associated with post‐transplantation mortality, hospital and intensive care unit length of stay ( LOS ), duration of mechanical ventilation, or primary graft dysfunction. Lung transplant recipients from 2000 to 2012 with a CT scan less than six months prior to transplant were included. Univariate, multivariate, and Kaplan–Meier analyses were conducted. Results Thirty‐six patients were included. Those with low muscle index (lower 25th percentile) had a worse survival (hazard ratio = 3.83; 95% confidence interval 1.42–10.3; p = 0.007) and longer hospital LOS by an estimated 7.2 d (p = 0.01) when adjusted for age and sex as compared to those with higher muscle index. Conclusion Low muscle index at lung transplantation is associated with worse survival and increased hospital LOS .

AbstractIntroductionFew studies have examined the effects of amyloid and apolipoprotein E (APOE) genotype on cognition among middle‐aged individuals.MethodsWe included 464 cognitively normal, test‐naïve, participants with Pittsburgh compound B positron emission tomography amyloid imaging, mean age of 62.7 (range, 51–71 years), enrolled in the Mayo Clinic Study of Aging. Participants completed multiple cognitive assessments, including a standard neuropsychological battery and the CogState computerized battery, over 30 months of follow‐up. Linear mixed models were used to examine the effects of amyloid and APOE genotype on baseline cognition and cognitive decline.ResultsElevated amyloid was not associated with tests of episodic memory but did predict declines on tests of executive function. APOE genotype was not associated with cognition. Among APOE ɛ4 noncarriers, higher amyloid was predictive of decline on tests of executive function and on one episodic memory test.DiscussionElevated amyloidosis and APOE genotype do not appear to exert a dramatic influence on cognition in middle age.

Objectives To determine the association between multiple chronic conditions and risk of incident mild cognitive impairment ( MCI ) and dementia. Design Prospective cohort study. Setting Olmsted County, Minnesota. Participants Cognitively normal individuals (N = 2,176) enrolled in the Mayo Clinic Study of Aging ( MCSA ). Measurements Participants were randomly selected from the community, evaluated by a physician, and underwent neuropsychometric testing at baseline and at 15‐month intervals to assess diagnoses of MCI and dementia. Information on International Classification of Diseases, Ninth Revision codes for chronic conditions in the 5 years before enrollment was electronically captured using the Rochester Epidemiology Project medical records linkage system. Multimorbidity was defined as having two or more chronic conditions, and the association between multimorbidity and MCI and dementia was examined using Cox proportional hazards models. Results Of 2,176 cognitively normal participants (mean age ± standard deviation 78.5 ± 5.2; 50.6% male), 1,884 (86.6%) had multimorbidity. The risk of MCI or dementia was higher in persons with multimorbidity (hazard ratio ( HR ) = 1.38, 95% confidence interval ( CI ) = 1.05–1.82) than in those with one or no chronic condition. The HR was of greater magnitude in persons with four or more conditions ( HR = 1.61, 95% CI = 1.21–2.13) than in those with two or three conditions ( HR = 1.03, 95% CI = 0.76–1.39) and for men with multimorbidity( HR = 1.53, 95% CI = 1.01–2.31) than for women with multimorbidity ( HR = 1.20, 95% CI = 0.83–1.74), compared to those with one or no chronic condition. Conclusion In older adults, having multiple chronic conditions is associated with greater risk of MCI and dementia. This is consistent with the hypothesis that multiple etiologies may contribute to MCI and late‐life dementia. Preventing chronic diseases may be beneficial in delaying or preventing MCI and dementia.

AbstractLung transplant recipients (LTR) at our institution receive prolonged and mostly lifelong azole antifungal (AF) prophylaxis. The impact of this prophylactic strategy on the epidemiology and outcome of invasive fungal infections (IFI) is unknown. This was a single‐center, retrospective cohort study. We reviewed the medical records of all adult LTR from January 2002 to December 2011. Overall, 16.5% (15 of 91) of patients who underwent lung transplantation during this time period developed IFI. Nineteen IFI episodes were identified (eight proven, 11 probable), 89% (17 of 19) of which developed during AF prophylaxis. LTR with idiopathic pulmonary fibrosis were more likely to develop IFI (HR: 4.29; 95% CI: 1.15–15.91; p = 0.03). A higher hazard of mortality was observed among those who developed IFI, although this was not statistically significant (hazard ratio [HR]: 1.71; 95% confidence interval [CI] [0.58–4.05]; p = 0.27). Aspergillus fumigatus was the most common cause of IFI (45%), with pulmonary parenchyma being the most common site of infection. None of our patients developed disseminated invasive aspergillosis, cryptococcal or endemic fungal infections. IFI continue to occur in LTR, and the eradication of IFI appears to be challenging even with prolonged prophylaxis. Azole resistance is uncommon despite prolonged AF exposure.

Despite preexisting cytomegalovirus (CMV) immunity, CMV‐seropositive liver transplantation (LT) patients remain at risk of CMV infection. We hypothesized that the pre‐transplant CMV antibody titer correlates with the risk of CMV reactivation. We conducted a retrospective study of CMV‐seropositive LT recipients who did not receive anti‐CMV prophylaxis from 2007 to 2013. The pre‐transplant CMV immunoglobulin G (IgG) titer, which was measured with an enzyme‐linked fluorescent immunoassay, was assessed as a risk factor for CMV reactivation with multivariate Cox proportional hazards models. The population consisted of 225 CMV‐seropositive LT patients with a median age of 57 years (interquartile range, 47‐62 years). The CMV titer distributions were as follows: <60 (40%) and ≥60 AU/mL (60%). The Kaplan‐Meier estimates for CMV infection were 17% at 3 months, 18% at 6 months, and 19% at 12 months after transplantation. In a univariate analysis, a marginally significant increased risk of CMV infection was seen in LT recipients with a pre‐transplant CMV IgG titer < 60 AU/mL versus ≥ 60 AU/mL [hazard ratio (HR), 1.79; 95% confidence interval (CI), 0.98‐3.28 (P =0.06)]. This risk was statistically significant in the subgroup of recipients who received allografts from CMV‐seropositive donors [HR, 2.21; 95% CI, 1.15‐4.26 (P =0.02)]. In a multivariate analysis, a pre‐transplant CMV IgG titer < 60 AU/mL was significantly associated with CMV infection [HR, 3.11; 95% CI, 1.60‐6.03 (P < 0.001)]. The other risk factors were high body mass index, donor CMV seropositivity, prolonged cold ischemic time, use of an interleukin‐2 receptor antagonist for induction therapy, and high numbers of post‐transplant infections. A lower pre‐transplant CMV antibody titer is significantly associated with CMV infection after LT. Quantitative measurement of CMV‐specific humoral immunity may have a potential role in improving the CMV prevention strategy in CMV‐seropositive LT recipients.Liver Transpl 21:539–546, 2015. © 2015 AASLD.