Back to Authors

Kremers, Walter K

0000-0001-5714-3473

Mayo Clinic

Mayo Clinic, Rochester, Minnesota.

Citations 181

Elevated ST2 levels are associated with antibody‐mediated rejection in heart transplant recipients

Clinical Transplantation | July 12, 2018 | Volume: 32 | Issue: 9 | Pages: No page available

10.1111/ctr.13349 | PMID 29998506

AbstractSoluble ST2 (sST2) is a novel biomarker of inflammation and fibrosis. Elevated sST2 levels (≥35 ng/mL) are associated with worse outcomes in patients with heart failure (HF). There are sparse data regarding the significance of sST2 levels after heart transplantation (HTx). The study aims were to evaluate trends in soluble ST2 levels after the resolution of HF status with HTx and association between post‐HTx sST2 levels and outcomes. Plasma sST2 levels were measured at baseline (median [IQR] of 118 days pre‐HTx) and 12 months post‐HTx in 62 subjects who were stratified into two groups by post‐HTx sST2 levels < or ≥35 ng/mL: “Group 1” or “Group 2,” respectively. Plasma sST2 levels were elevated in 58% of patients pre‐HTx and in 50% of patients post‐HTx. There was no association between elevated sST2 levels before and after HTx, and no significant differences in baseline characteristics between Group 1 and Group 2 patients. Group 2 as compared to Group 1 HTx recipients had significantly higher incidence of antibody‐mediated rejection (AMR) for the entire post‐transplant follow‐up period (32% vs 4%, P = 0.006). There was no association between post‐HTx sST2 level status and other post‐HTx outcomes including survival. In conclusion, elevated plasma sST2 levels after HTx are associated with increased risk for AMR.
Mediterranean Diet, Its Components, and Amyloid Imaging Biomarkers

Journal of Alzheimer’s Disease | June 8, 2018 | Volume: 64 | Issue: 1 | Pages: 281-290

10.3233/jad-171121 | PMID 29889074

Background: There is accumulating evidence suggesting that diet may play a role in preventing or delaying cognitive decline and dementia, but the underlying biological mechanisms are not well understood. Objectives: To examine the cross-sectional associations of the Mediterranean diet (MeDi) and its components with 11 C-PiB-PET scan measures of amyloid-β (Aβ) deposition. Methods: The study consisted of 278 Mayo Clinic Study of Aging participants 70+ years old, who were cognitively unimpaired (CU) at the time of completion of the Food Frequency Questionnaire (FFQ) and when they underwent PET imaging. Adherence to the MeDi was assessed by computing the MeDi score for each participant. All scans were performed after the FFQ completion; median [IQR] time between FFQ and Aβ PET was 3.5 (1.4) years. Z-scores were created for component, macro- and micronutrients measured. Linear and logistic regression models were adjusted for age, sex, education, apolipoprotein E (APOE) ɛ4 allele carrier status, time interval between the FFQ completion and PET scan, and total energy intake. Results: Participants’ median age at FFQ was 77.7 years (55.8% men; 26.6% with an APOE ɛ4 allele). Higher MeDi score (linear regression slope (beta):–0.035, p = 0.012; per standard deviation increase), vegetable intake (beta:–0.043, p = 0.002), intake of vitamin A (beta:–0.041, p = 0.003) or β-carotene (beta: –0.039, p = 0.005) from food sources and moderate alcohol consumption (beta: –0.074, p = 0.03) were associated with lower 11 C-PiB standardized uptake value ratio. Conclusion: Findings are consistent with previous studies suggesting that higher adherence to a MeDi pattern and higher vegetable consumption are associated with better neuroimaging biomarker profile. Prospective studies are needed to validate current findings.
Clinical and Pathology Findings Associate Consistently with Larger Glomerular Volume

Journal of the American Society of Nephrology | May 22, 2018 | Volume: 29 | Issue: 7 | Pages: 1960-1969

10.1681/asn.2017121305 | PMID 29789431

Background Glomerular volume increases when demand exceeds nephron supply, which may lead to glomerulosclerosis. It is unclear if determinants of glomerular volume are consistent between populations that differ by severity of comorbidities. Methods We studied kidney biopsy specimens from living kidney donors ( n =2453) and patients who underwent radical nephrectomy for a renal tumor ( n =780). We scanned specimen sections into high-resolution digital images, manually traced glomerular profiles, and calculated mean glomerular volumes using the Weibel–Gomez stereologic formula (separately for nonsclerosed glomeruli and globally sclerosed glomeruli). We then assessed the relationship of glomerular volume with age, clinical characteristics, and nephrosclerosis on biopsy specimen. Results Compared with kidney donors, patients with tumors were older and more frequently men, obese, diabetic, or hypertensive, had more glomerulosclerosis and interstitial fibrosis on biopsy specimen, and had 12% larger nonsclerosed glomeruli ( P <0.001). In both populations, male sex, taller height, obesity, hypertension, and proteinuria associated with larger nonsclerosed glomeruli to a similar extent. In patients with tumors, diabetes, glomerulosclerosis >25%, and interstitial fibrosis >25% also associated with larger nonsclerosed glomeruli. Independent clinical predictors of larger nonsclerotic glomeruli were family history of ESRD, male sex, taller height, obesity, diabetes, and proteinuria. After adjustment for these characteristics, nonsclerotic glomerular volume did not differ between populations and was stable up to age 75 years, after which it decreased with age. Many of these findings were also evident with globally sclerotic glomerular volume. Conclusions Characteristics associated with glomerular volume are consistent between patient populations with low and high levels of comorbidity.
Prevalence and Outcomes of Amyloid Positivity Among Persons Without Dementia in a Longitudinal, Population-Based Setting

JAMA Neurology | April 30, 2018 | Volume: 75 | Issue: 8 | Pages: 970

10.1001/jamaneurol.2018.0629 | PMID 29710225

FDG-PET in tau-negative amnestic dementia resembles that of autopsy-proven hippocampal sclerosis

Brain | February 7, 2018 | Volume: 141 | Issue: 4 | Pages: 1201-1217

10.1093/brain/awy049 | PMID 29538658

De novo donor‐specific antibody following BK nephropathy: The incidence and association with antibody‐mediated rejection

Clinical Transplantation | January 10, 2018 | Volume: 32 | Issue: 3 | Pages: No page available

10.1111/ctr.13194 | PMID 29315820

AbstractBackground and objectivesThe risk of de novo donor‐specific antibody (dnDSA) development following BK viremia (BKV) or nephropathy (BKN) after kidney transplant remains unclear. We aimed to evaluate the relationships among dnDSA, BKV (BK blood PCR > 15 000 copies), BKN, antibody‐mediated rejection (AMR), and allograft loss.Patients and methodsWe performed a retrospective cohort study of 904 solitary kidney transplant recipients transplanted between 10/2007 and 5/2014. Cox proportional hazards regression with time‐dependent covariates were used to assess the relationships among BKN, isolated BKV, dnDSA, and the subsequent risk of AMR and allograft loss.ResultsIn multivariate analysis, we observed that BKN, but not BKV was a risk factor for dnDSA (HR, 3.18, P = .008). Of the patients with BK nephropathy, 14.0% (6/43) developed dnDSA, which occurred within 14 months of BK diagnosis. DnDSA in this setting remains a risk factor for subsequent AMR (HR 4.75, P = .0001) and allograft loss (HR 2.63, P = .018).ConclusionsBKN is an independent risk factor for development of dnDSA. Improved understanding of the characteristics of patients with BKN who are at highest risk for development of dnDSA would be valuable to customize immunosuppression reduction in this population.
Impact of Patient Reminders on Papanicolaou Test Completion for High-Risk Patients Identified by a Clinical Decision Support System

Journal of Women's Health | January 3, 2018 | Volume: 27 | Issue: 5 | Pages: 569-574

10.1089/jwh.2017.6667 | PMID 29297754

Background: A clinical decision support system (CDSS) for cervical cancer screening identifies patients due for routine cervical cancer screening. Yet, high-risk patients who require more frequent screening or earlier follow-up to address past abnormal results are not identified. We aimed to assess the effect of a complex CDSS, incorporating national guidelines for high-risk patient screening and abnormal result management, its implementation to identify patients overdue for testing, and the outcome of sending a targeted recommendation for follow-up. Materials and Methods: At three primary care clinics affiliated with an academic medical center, a reminder recommending an appointment for Papanicolaou (Pap) testing or Pap and human papillomavirus cotesting was sent to high-risk women aged 18 through 65 years (intervention group) identified by CDSS as overdue for testing. Historical control patients, who did not receive a reminder, were identified by CDSS 1 year before the date when reminders were sent to the intervention group. Test completion rates were compared between the intervention and control groups through a generalized estimating equation extension. Results: Across the three sites, the average completion rate of recommended follow-up testing was significantly higher in the intervention group at 23.7% (61/257) than the completion rate at 3.3% (17/516) in the control group ( p < 0.001). Conclusions: A CDSS with enhanced capabilities to identify high-risk women due for cervical cancer testing beyond routine screening intervals, with subsequent patient notification, has the potential to decrease cervical precancer and cancer by improving adherence to guideline-compliant follow-up and needed treatment.
Prevalence and Natural History of Superficial Siderosis

Stroke | October 26, 2017 | Volume: 48 | Issue: 12 | Pages: 3210-3214

10.1161/strokeaha.117.018974 | PMID 29070715

Background and Purpose— Superficial siderosis (SS) is characterized by hemosiderin deposition in the superficial layers of the central nervous system and can be seen during postmortem examination or with iron-sensitive magnetic resonance imaging techniques. The distribution of SS may predict the probable underlying cause. This study aimed to report the prevalence and natural history of SS in a population-based study. Methods— Brain magnetic resonance imaging scans from the MCSA (Mayo Clinic Study of Aging), a population-based study of residents 50 to 89 years of age in Olmsted County, Minnesota, were reviewed. Participants with imaging consistent with SS were identified from 2011 through 2016. An inverse probability weighting approach was used to convert our observed frequencies to population prevalence of SS. Additional data abstracted included amyloid positron emission tomography, Apolipoprotein E genotype, coexisting cerebral microbleeds, and extent of SS. Results— A total of 1412 participants had eligible magnetic resonance imaging scans. Two participants had infratentorial SS, restricted to the posterior fossa. Thirteen participants had cortical SS involving the cerebral convexities (7 focal and 6 disseminated). Only 3 of the participants with cortical SS (23%) also had cerebral microbleeds. The population prevalence of SS was 0.21% (95% confidence interval, 0–0.45) in those 50 to 69 years old and 1.43% (confidence interval, 0.53–2.34) in those over 69 years old. Apolipoprotein E ε2 allele was more common in those with SS (57.1% versus 15.0%; P <0.001). Compared with participants without SS, those with SS were also more likely to have a positive amyloid positron emission tomographic scan (76.9% versus 29.8%; P <0.001). Conclusions— SS may be encountered in the general elderly population. The association with increased amyloid burden and Apolipoprotein E ε2 genotype supports cerebral amyloid angiopathy as the most common mechanism. Longitudinal follow-up is needed to evaluate the risk of subsequent hemorrhage in cases of incidentally discovered SS.
Weighting and standardization of frequencies to determine prevalence of AD imaging biomarkers

Neurology | October 14, 2017 | Volume: 89 | Issue: 20 | Pages: 2039-2048

10.1212/wnl.0000000000004652 | PMID 29030451

Importance of Routine Antihuman/Leukocyte Antibody Monitoring

Circulation | October 2, 2017 | Volume: 136 | Issue: 14 | Pages: 1350-1352

10.1161/circulationaha.117.029964 | PMID 28972064