Comparing Kidney Health Outcomes in Children, Adolescents, and Adults With Focal Segmental Glomerulosclerosis

IMPORTANCE

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease (ESKD) across the lifespan. While 10% to 15% of children and 3% of adults who develop ESKD have FSGS, it remains uncertain whether the natural history differs in pediatric vs adult patients, and this uncertainty contributes to the exclusion of children and adolescents in clinical trials.

OBJECTIVE

To examine whether there are differences in the kidney health outcomes among children, adolescents, and adults with FSGS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used pooled and parallel analyses, completed July 5, 2022, from 3 complimentary data sources: (1) Nephrotic Syndrome Rare Disease Clinical Research Network (NEPTUNE); (2) FSGS clinical trial (FSGS-CT); and (3) Kidney Research Network (KRN). NEPTUNE is a multicenter US/Canada cohort study; FSGS-CT is a multicenter US/Canada clinical trial; and KRN is a multicenter US electronic health record-based registry from academic and community nephrology practices. NEPTUNE included 166 patients with incident FSGS enrolled at first kidney biopsy; FSGS-CT included 132 patients with steroid-resistant FSGS randomized to cyclosporine vs dexamethasone with mycophenolate; and KRN included 184 patients with prevalent FSGS. Data were collected from November 2004 to October 2019 and analyzed from October 2020 to July 2022.

EXPOSURES

Age: children (age <13 years) vs adolescents (13-17 years) vs adults (≥18 years). Covariates of interest included sex, disease duration, APOL1 genotype, urine protein-to-creatinine ratio, estimated glomerular filtration rate (eGFR), edema, serum albumin, and immunosuppressive therapy.

MAIN OUTCOMES AND MEASURES

ESKD, composite outcome of ESKD or 40% decline in eGFR, and complete and/or partial remission of proteinuria.

RESULTS

The study included 127 (26%) children, 102 (21%) adolescents, and 253 (52%) adults, including 215 (45%) female participants and 138 (29%) who identified as Black, 98 (20%) who identified as Hispanic, and 275 (57%) who identified as White. Overall, the median time to ESKD was 11.9 years (IQR, 5.2-19.1 years). There was no difference in ESKD risk among children vs adults (hazard ratio [HR], 0.67; 95% CI, 0.43-1.03) or adolescents vs adults (HR, 0.85; 95% CI, 0.52-1.36). The median time to the composite end point was 5.7 years (IQR 1.6-15.2 years), with hazard ratio estimates for children vs adults of 1.12 (95% CI, 0.83-1.52) and adolescents vs adults of 1.06 (95% CI, 0.75-1.50).

CONCLUSIONS AND RELEVANCE

In this study, the association of FSGS with kidney survival and functional outcomes was comparable at all ages.

[Promoting young academics in anesthesiology: factors for an attractive internship]

BACKGROUND

Practical experiences in clinical traineeships can shape the later specialty choice of medical students.

KEY QUESTION

The following study aimed to find factors in anesthesiological clinical traineeship that encourage students to specialize in the field.

MATERIAL AND METHODS

As part of a nationwide online survey conducted by the working group for education of the German Association for Orthopedics and Trauma Surgery (Deutsche Gesellschaft für Orthopädie und Unfallchirurgie, DGOU), study participants (n = 479) answered questions about their minimum 4‑week traineeship in anesthesiology. The information on items was analyzed in six content categories: 1) integration into the team, 2) acquisition of skills, 3) teachers, 4) quality of teaching, 5) structure of teaching and 6) satisfaction with the clinical internship. The respondents were subdivided into 4 groups by answering the question "Could you imagine an elective in anesthesiology during the final year (PJ)" with "Yes, I have made this decision after the clinical traineeship" (JdF, n = 212, 44%), "No I have decided against an elective during the final year after the traineeship" (NdF, n = 56, 12%), "Yes I have decided for an elective in anesthesiology before the internship" (JvF Yes: n = 144, 30%) and "No, I have decided against an elective in anesthesiology before the internship" (NvF: n = 67, 14%). Answers of the participants regarding the six content categories were compared between the four groups.

RESULTS

The survey reached all medical faculties in Germany and included participants with an average age of 25.8 years and a balanced gender ratio. There were significant differences between satisfied and dissatisfied students in all four subgroups. Of the 479 respondents, 211 (44%) were already set regarding their decision of choosing anesthesiology as an elective during the final year before the clinical traineeship. Of the respondents 268 (56%) were influenced by the internship, 212 (44%) of them positively. In total, 81% of the trainees rated the internship as "satisfying". Students who were satisfied with the overall internship and who spoke in favor of the PJ elective in anesthesiology differed significantly from the other groups in the categories of team integration, skills acquisition, structure and quality of teaching. The teaching of practical skills and specialist knowledge as well as the integration into diagnostics and treatment planning promoted the recruitment of young people.

DISCUSSION

The positively evaluated anesthesiology internship promotes later specialty choice, with quality and structure of the teaching affecting student satisfaction. Trainees who were attracted by anesthesiology gave better overall ratings and acquired more skills during the course of the internship. In order to win aspiring doctors for anesthesiology, the medical team has to integrate trainees well and support the acquisition of practical skills and specialist knowledge. In addition, didactics and practical relevance should be given high priority.

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Similarities and Differences in Interoceptive Bodily Awareness Between US-American and Japanese Cultures: A Focus-Group Study in Bicultural Japanese-Americans

Interoceptive awareness is the conscious perception of sensations that create a sense of the physiological condition of the body. A validation study for the Japanese translation of the Multidimensional Assessment of Interoceptive Awareness (MAIA) surprised with a factor structure different from the original English-language version by eliminating two of eight scales. This prompted an exploration of the similarities and differences in interoceptive bodily awareness between Japanese and European Americans. Bicultural Japanese-Americans discussed concepts and experiences in the two cultures. We conducted focus groups and qualitative thematic analyses of transcribed recordings. 16 participants illustrated cross-cultural differences in interoceptive bodily awareness: switching between languages changes embodied experience; external versus internal attention focus; social expectations and body sensations; emphasis on form versus self-awareness; personal space; and mind-body relationship; context dependency of bodily awareness and self-construal. The participants explained key concepts that present challenges for a Japanese cultural adaptation of the MAIA, specifically the concept of self-regulation lost in the factor analysis. In Japanese culture, self-regulation serves the purpose of conforming to social expectations, rather than achieving an individual self-comforting sense of homeostasis. Our findings will inform the next phase of improving the MAIA's cross-cultural adaptation.

Kidney Injury Molecule-1 and Periostin Urinary Excretion and Tissue Expression Levels and Association with Glomerular Disease Outcomes

Introductions

Kidney injury molecule-1 (KIM-1) and periostin (POSTN) are proximal and distal tubule injury biomarkers. We tested whether baseline urine KIM-1/creatinine (uKIM-1/cr) and/or uPOSTN/cr correlated with disease severity or improved a remission prediction model.

Methods

Baseline uKIM1/cr and uPOSTN/cr were measured on spot urine samples from immunosuppression-free patients enrolled in Nephrotic Syndrome Study Network until December 15, 2014. Urine protein/creatinine (UPCR) and albumin/creatinine (UACR) were measured at baseline, 4 months, and until last follow-up. Glomerular and tubulointerstitial (TI) expression arrays were analyzed from a baseline research renal biopsy core collected during a clinically indicated biopsy.Renal diagnoses were centrally confirmed, sections scanned, and measured morphometrically. Correlations between baseline uKIM-1/cr and uPOSTN/cr and UPCR, UACR, histopathologic features, glomerular and TI KIM-1 and POSTN expression levels, and renal outcomes were assessed.

Results

Baseline uKIM-1/cr correlated with UPCR and UACR, and were associated with complete remission after adjustment for proteinuria, histopathologic diagnosis, and treatment. Baseline uKIM-1/cr also correlated with degree of foot process effacement and acute tubular injury. Glomerular and TI KIM-1 expression levels correlated with UPCR and UACR. Higher TI KIM-1 expression levels correlated with interstitial fibrosis, tubular atrophy, and global glomerulosclerosis, while glomerular KIM-1 expression correlated with time to remission. Findings for POSTN were of lesser statistical strength.

Discussion/Conclusion

Lower baseline uKIM-1/cr values were associated with more rapid time to complete remission after adjusting for proteinuria, histopathologic diagnosis, and treatment. Increased TI KIM-1 expression levels in proteinuric states were associated with chronic morphological injury; lower glomerular expression levels were associated with a greater potential for proteinuria reversibility.

Persistent Disease Activity in Patients With Long-Standing Glomerular Disease

Introduction

Methods

Results

Conclusion

ACE inhibitors in SSc patients display a risk factor for scleroderma renal crisis-a EUSTAR analysis

Objectives

To investigate the effect of ACE inhibitors (ACEi) on the incidence of scleroderma renal crisis (SRC) when given prior to SRC in the prospectively collected cohort from the European Scleroderma Trial and Research Group (EUSTAR).

Methods

SSc patients without prior SRC and at least one follow-up visit were included and analyzed regarding SRC, arterial hypertension, and medication focusing on antihypertensive medication and glucocorticoids (GC).

Results

Out of 14,524 patients in the database, we identified 7648 patients with at least one follow-up. In 27,450 person-years (py), 102 patients developed SRC representing an incidence of 3.72 (3.06–4.51) per 1000 py. In a multivariable time-to-event analysis adjusted for age, sex, disease severity, and onset, 88 of 6521 patients developed SRC. The use of ACEi displayed an increased risk for the development of SRC with a hazard ratio (HR) of 2.55 (95% confidence interval (CI) 1.65–3.95). Adjusting for arterial hypertension resulted in a HR of 2.04 (95%CI 1.29–3.24). There was no evidence for an interaction of ACEi and arterial hypertension (HR 0.83, 95%CI 0.32–2.13, p = 0.69). Calcium channel blockers (CCB), angiotensin receptor blockers (ARB), endothelin receptor antagonists, and GC—mostly in daily dosages below 15 mg of prednisolone—did not influence the hazard for SRC.

Conclusions

ACEi in SSc patients with concomitant arterial hypertension display an independent risk factor for the development of SRC but are still first choice in SRC treatment. ARBs might be a safe alternative, yet the overall safety of alternative antihypertensive drugs in SSc patients needs to be further studied.

Time to Initiation of Antihypertensive Therapy After Onset of Elevated Blood Pressure in Patients With Primary Proteinuric Kidney Disease

Rationale & Objective

The objective of the study was to estimate the prevalence of hypertension in patients with proteinuric kidney disease and evaluate blood pressure (BP) control.

Study Design

Retrospective cohort study.

Setting & Participants

Data from adults and children with proteinuric kidney disease enrolled in the multicenter Kidney Research Network Registry were used for this study.

Exposure

Proteinuric kidney disease.

Outcomes

Hypertension and BP control.

Analytical Approach

Patients with white-coat hypertension were excluded. Patients were censored at end-stage kidney disease onset. Patients were defined as hypertensive either by hypertension diagnosis code, having 2 or more encounters with elevated BPs, or treatment with antihypertensive therapy excluding renin-angiotensin-aldosterone system blockade. Elevated BP was defined as greater than 95th percentile for children and >140/90 mm Hg in adults. Sustained BP control was defined as 2 or more consecutive encounters with BPs lower than 95th percentile for children and <140/90 mm Hg for adults. Kaplan-Meier and Cox proportional hazards analyses were used to evaluate the time to initiation of antihypertensive therapy.

Results

842 patients, 69% adults and 31% children, with a total observation period of 6,722 patient-years were included in the analysis. 644 (76%) had hypertension during observation. There was no difference in the prevalence of hypertension between children and adults (74% vs 78%; P = 0.3). Hypertension was most common among those of African American race compared with other races (90% vs 72%-75%; P = 0.003). 504 (78%) patients with hypertension achieved BP control but only 51% achieved control within 1 year. 140 (22%) patients with hypertension never achieved BP control during a median of 41 (IQR, 24-73) months of observation.

Limitations

Differing BP control goals that may lead to overestimation of the controlled patient population.

Conclusions

Hypertension affects most patients with proteinuric kidney disease regardless of age. Time to BP control exceeded 1 year in 50% of patients with hypertension and 22% did not demonstrate control. This study highlights the need to address hypertension early and completely in disease management of patients with proteinuric kidney disease.

Myelopreservation with the CDK4/6 inhibitor trilaciclib in patients with small-cell lung cancer receiving first-line chemotherapy: a phase Ib/randomized phase II trial

BACKGROUND

Chemotherapy-induced damage of hematopoietic stem and progenitor cells (HSPC) causes multi-lineage myelosuppression. Trilaciclib is an intravenous CDK4/6 inhibitor in development to proactively preserve HSPC and immune system function during chemotherapy (myelopreservation). Preclinically, trilaciclib transiently maintains HSPC in G1 arrest and protects them from chemotherapy damage, leading to faster hematopoietic recovery and enhanced antitumor immunity.

PATIENTS AND METHODS

This was a phase Ib (open-label, dose-finding) and phase II (randomized, double-blind placebo-controlled) study of the safety, efficacy and PK of trilaciclib in combination with etoposide/carboplatin (E/P) therapy for treatment-naive extensive-stage small-cell lung cancer patients. Patients received trilaciclib or placebo before E/P on days 1-3 of each cycle. Select end points were prespecified to assess the effect of trilaciclib on myelosuppression and antitumor efficacy.

RESULTS

A total of 122 patients were enrolled, with 19 patients in part 1 and 75 patients in part 2 receiving study drug. Improvements were seen with trilaciclib in neutrophil, RBC (red blood cell) and lymphocyte measures. Safety on trilaciclib+E/P was improved with fewer ≥G3 adverse events (AEs) in trilaciclib (50%) versus placebo (83.8%), primarily due to less hematological toxicity. No trilaciclib-related ≥G3 AEs occurred. Antitumor efficacy assessment for trilaciclib versus placebo, respectively, showed: ORR (66.7% versus 56.8%, P = 0.3831); median PFS [6.2 versus 5.0 m; hazard ratio (HR) 0.71; P = 0.1695]; and OS (10.9 versus 10.6 m; HR 0.87; P = 0.6107).

CONCLUSION

Trilaciclib demonstrated an improvement in the patient's tolerability of chemotherapy as shown by myelopreservation across multiple hematopoietic lineages resulting in fewer supportive care interventions and dose reductions, improved safety profile, and no detriment to antitumor efficacy. These data demonstrate strong proof-of-concept for trilaciclib's myelopreservation benefits.

CLINICAL TRAIL NUMBER

NCT02499770.

P720Atheroprotective effects of 17beta-estradiol are mediated by PPARgamma in human coronary artery smooth muscle cells

Background

17β-estradiol (E2) mediates vasculoprotection in various preclinical and clinical models of atherosclerosis and neointimal hyperplasia. However, the molecular mechanisms underlying these effects are still not fully elucidated. Previous studies have demonstrated the essential role of the peroxisome-proliferator-activated-receptor-γ (PPARγ) in mediating vasculoprotective effects of E2 in vivo. The aim of the current study was to investigate whether PPARγ is implicated in mediating vasculoprotective mechanisms of E2 in human coronary artery smooth muscle cells (HCASMC).

Methods

Primary HCASMC were purchased and stimulated with E2 [10 nM], the selective estrogen receptor α (ERα) agonist propylpyrazole triol (PPT) [50 nM] and the selective ERα antagonist methyl-piperidino-pyrazole (MPP) [1 μM], respectively. Changes in PPARγ mRNA and protein expression upon stimulation of ERα were assessed by qPCR and Western blot analyses. Nuclear PPARγ protein expression and DNA binding affinity was assessed after the isolation of the nuclear protein fraction. Hereafter, HCASMC were incubated with E2, PPARγ-antagonist GW9662 [1 μM – 30 μM], or both. HCASMC proliferation was assessed by nuclear BrdU staining and reactive oxygen species (ROS) formation was assessed by L-012- and DCF-DA assays.

Results

E2 significantly increased PPARγ expression in HCASMC (1.95±0.41 –fold; n=5; p=0.0335). This effect was mimicked by ERα agonist PPT (1.63±0.27 –fold; n=7; p=0.0489) and was abrogated by co-incubation with ERα antagonist MPP (1.17±0.18 –fold; n=3; pvs. control >0.05). Nuclear PPARγ expression was enhanced by E2 (1.53±0.16 –fold; n=4; pvs. control = 0.0074; Fig. 2A) whereas PPARγ's DNA binding activity to PPRE remained unchanged upon stimulation with E2 (0.94±0.11 –fold; n=4; pvs. control >0.05). Pharmacological inhibition of PI3K/Akt by LY294002 abrogated E2-induced expression of PPARγ (0.24±0.09 –fold; n=3; pvs. E2 = 0.0017), arguing for a PI3K/Akt-dependent activation by E2. The role of PPARγ in mediating vasculoprotective effects of E2 was assessed in functional assays using PPARγ-antagonist GW9662. E2 diminished HCASMC proliferation which was restored by GW9662. While E2 only slightly decreased ROS production by HCASMC, GW9662 significantly increased ROS levels (1,036±169 RLU x s–1 x cell–1 versus 561±99 RLU x s–1 x cell–1; n=5–6; p=0.0287).

Conclusion

In summary, the present study identifies PPARγ as a downstream mediator of E2-related atheroprotective effects in HCASMC. 17β-estradiol regulates vascular PPARγ-expression in HCASMC via the ERα receptor and the PI3K/Akt pathway. PPARγ agonism might be a promising therapeutic strategy to prevent cardiovascular events in postmenopausal women with depleted E2 plasma levels.

Acknowledgement/Funding

This work was supported by the Bonfor program of the University of Bonn [grant number O-109.0057 to JJ].

DUET: A Phase 2 Study Evaluating the Efficacy and Safety of Sparsentan in Patients with FSGS

BACKGROUND

We evaluated and compared the effects of sparsentan, a dual endothelin type A (ET_A) and angiotensin II type 1 receptor antagonist, with those of the angiotensin II type 1 receptor antagonist irbesartan in patients with primary FSGS.

METHODS

In this phase 2, randomized, double-blind, active-control Efficacy and Safety of Sparsentan (RE-021), a Dual Endothelin Receptor and Angiotensin Receptor Blocker, in Patients with Focal Segmental Glomerulosclerosis (FSGS): A Randomized, Double-blind, Active-Control, Dose-Escalation Study (DUET), patients aged 8-75 years with biopsy-proven FSGS, eGFR>30 ml/min per 1.73 m², and urinary protein-to-creatinine ratio (UP/C) ≥1.0 g/g received sparsentan (200, 400, or 800 mg/d) or irbesartan (300 mg/d) for 8 weeks, followed by open-label sparsentan only. End points at week 8 were reduction from baseline in UP/C (primary) and proportion of patients achieving FSGS partial remission end point (FPRE) (UP/C: ≤1.5 g/g and >40% reduction [secondary]).

RESULTS

Of 109 patients randomized, 96 received study drugs and had baseline and week 8 UP/C measurements. Sparsentan-treated patients had greater reductions in UP/C than irbesartan-treated patients did when all doses (45% versus 19%; P=0.006) or the 400 and 800 mg doses (47% versus 19%; P=0.01) were pooled for analysis. The FSGS partial remission end point was achieved in 28% of sparsentan-treated and 9% of irbesartan-treated patients (P=0.04). After 8 weeks of treatment, BP was reduced with sparsentan but not irbesartan, and eGFR was stable with both treatments. Overall, the incidence of adverse events was similar between groups. Hypotension and edema were more common among sparsentan-treated patients but did not result in study withdrawals.

CONCLUSIONS

Patients with FSGS achieved significantly greater reductions in proteinuria after 8 weeks of sparsentan versus irbesartan. Sparsentan was safe and well tolerated.

First-in-human phase 0 study of 111In-CHX-A"-DTPA trastuzumab for HER2 tumor imaging

Introduction:

Tumors over-expressing the human epithelial receptor 2 (HER2) or exhibiting amplification or mutation of its proto-oncogene have a poorer prognosis. Using trastuzumab and/or other HER2 targeted therapies can increase overall survival in patients with HER2(+) tumors making it critical to accurately identify patients who may benefit. We report on a Phase 0 study of the imaging agent, ¹¹¹In-CHX-A”-DTPA trastuzumab, in patients with known HER2 status to evaluate its safety and biodistribution and to obtain preliminary data regarding its ability to provide an accurate, whole-body, non-invasive means to determine HER2 status.

Methods:

¹¹¹In-CHX-A”-DTPA trastuzumab was radiolabeled on-site and slowly infused into 11 patients who underwent single (n=5) or multiple (n=6) ɣ-camera (n=6) and/or SPECT (n=8) imaging sessions.

Results:

No safety issues were identified. Visual and semi-quantitative imaging data were concordant with tissue HER2 expression profiling in all but 1 patient. The biodistribution showed intense peak liver activity at the initial imaging timepoint (3.3h) and a single-phase clearance fit of the average time-activity curve (TAC) estimated t_1/2=46.9h (R²=0.97; 95%CI 41.8 to 53h). This was followed by high gastrointestinal (GI) tract activity peaking by 52h. Linear regression predicted GI clearance by 201.2h (R² =0.96; 95%CI 188.5 to 216.9h). Blood pool had lower activity with its maximum on the initial images. Non-linear regression fit projected a t_1/2=34.2h (R² =0.96; 95%CI 25.3 to 46.3h). Assuming linear whole-body clearance, linear regression projected complete elimination (x-intercept) at 256.5hr (R²=0.96; 95%CI 186.1 to 489.2h).

Conclusion:

¹¹¹In-CHX-A”-DTPA trastuzumab can be safely imaged in humans. The biodistribution allowed for visual and semiquantitative analysis with results concordant with tissue expression profiling in 10 of 11 patients. Advances in Knowledge and Implications for Patient Care Using readily available components and on-site radiolabeling ¹¹¹In-CHX-A”-DTPA trastuzumab SPECT imaging may provide an economical, non-invasive means to detect HER2 over-expression.

Glycemic control of type 2 diabetes mellitus across stages of renal impairment: information for primary care providers

Chronic kidney disease (CKD) is a frequent complication of type 2 diabetes mellitus (T2DM) and elevates individuals' risk for cardiovascular disease, the leading cause of morbidity and mortality in T2DM. Achieving and maintaining tight glycemic control is key to preventing development or progression of CKD; however, improving glycemic control may be limited by effects of renal impairment on the efficacy and safety of T2DM treatments, necessitating dosing adjustments and careful evaluation of contraindications. Understanding the treatment considerations specific to each class of T2DM medication is important in individualizing therapy and improving glycemic, renal, and cardiovascular outcomes. Traditional glucose-lowering treatments include insulin, metformin, sulfonylureas, meglitinides, and thiazolidinediones. Each of these agents exhibits altered pharmacokinetics in patients with renal impairment except for the thiazolidinediones, which are metabolized by the liver and do not accumulate appreciably in patients with renal impairment. Newer glucose-lowering treatments include GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors. Of these, only the DPP-4 inhibitor linagliptin can be used across all stages of renal impairment without dosing restrictions or concerns regarding dose escalation, and all SGLT2 inhibitors are contraindicated when eGFR <45 mL/min/1.73m². Several of the newer treatments have also been investigated for effects on renal and cardiovascular outcomes, demonstrating potential benefits of the GLP-1 agonists liraglutide and semaglutide, as well as the SGLT2 inhibitors canagliflozin and empagliflozin, in reducing risk for some adverse renal and cardiovascular events. In addition, some DPP-4 inhibitors have been shown to reduce albuminuria, an indicator of glomerular dysfunction. Consideration of this information is useful in informing optimal management strategies for patients with T2DM and concomitant CKD. More clinical data from future and ongoing clinical trials, including data regarding potential renal and cardiovascular benefits, will be important in clarifying the safety and efficacy profiles of each of these agents in patients with CKD.

Randomized Clinical Trial Design to Assess Abatacept in Resistant Nephrotic Syndrome

Introduction

Treatment-resistant nephrotic syndrome is a rare form of glomerular disease that occurs in children and adults. No Food and Drug Administration-approved treatments consistently achieve remission of proteinuria and preservation of kidney function. CD80 (B7-1) can be expressed on injured podocytes, and administration of abatacept (modified CTLA4-Ig based on a natural ligand to CD80) has been associated with sustained normalization of urinary protein excretion and maintenance of glomerular filtration rate in experimental and clinical settings.

Methods

In this report, we describe the rationale for and design of a randomized, placebo-controlled, clinical trial of abatacept in patients with treatment-resistant nephrotic syndrome caused by focal segmental glomerulosclerosis or minimal change disease. The design is a hybrid of a parallel-group and crossover design (switchover) with the primary objectives assessed in the first period of the study and the secondary objectives assessed using data from both periods. All participants will receive the active agent in 1 of the periods. The duration of treatment will be 4 months per period.

Results

The primary outcome will be improvement in nephrotic-range proteinuria to subnephrotic range, that is, reduction from baseline to 4 months in urine protein:creatinine ratio ≥ 50% and to a level < 3. The projected sample size is 90 patients, which has 80% power to detect a treatment difference of 28%.

Conclusion

This study advances efforts to validate CD80 as a therapeutic target for treatment-resistant nephrotic syndrome, and implements a precision medicine-based approach to this serious kidney condition in which the selection of a therapeutic agent is guided by the underlying disease mechanism operating in individual patients.

Utility of 18F-fluoroestradiol (18F-FES) PET/CT imaging as a pharmacodynamic marker in patients with refractory estrogen receptor-positive solid tumors receiving Z-endoxifen therapy

BACKGROUND

Z-endoxifen is the most potent of the metabolites of tamoxifen, and has the potential to be more effective than tamoxifen because it bypasses potential drug resistance mechanisms attributable to patient variability in the expression of the hepatic microsomal enzyme CYP2D6. ¹⁸F-FES is a positron emission tomography (PET) imaging agent which selectively binds to estrogen receptor alpha (ER-α) and has been used for non-invasive in vivo assessment of ER activity in tumors. This study utilizes ¹⁸F-FES PET imaging as a pharmacodynamic biomarker in patients with ER+ tumors treated with Z-endoxifen.

METHODS

Fifteen patients were recruited from a parent therapeutic trial of Z-endoxifen and underwent imaging with ¹⁸F-FES PET at baseline. Eight had positive lesions on the baseline scan and underwent follow-up imaging with ¹⁸F-FES 1-5 days post administration of Z-endoxifen.

RESULTS

Statistically significant changes (p = 0.0078) in standard uptake value (SUV)-Max were observed between the baseline and follow-up scans as early as 1 day post drug administration.

CONCLUSION

F-FES PET imaging could serve as a pharmacodynamic biomarker for patients treated with ER-directed therapy.

Selecting SNPs informative for African, American Indian and European Ancestry: application to the Family Investigation of Nephropathy and Diabetes (FIND)

Background

The presence of population structure in a sample may confound the search for important genetic loci associated with disease. Our four samples in the Family Investigation of Nephropathy and Diabetes (FIND), European Americans, Mexican Americans, African Americans, and American Indians are part of a genome- wide association study in which population structure might be particularly important. We therefore decided to study in detail one component of this, individual genetic ancestry (IGA). From SNPs present on the Affymetrix 6.0 Human SNP array, we identified 3 sets of ancestry informative markers (AIMs), each maximized for the information in one the three contrasts among ancestral populations: Europeans (HAPMAP, CEU), Africans (HAPMAP, YRI and LWK), and Native Americans (full heritage Pima Indians). We estimate IGA and present an algorithm for their standard errors, compare IGA to principal components, emphasize the importance of balancing information in the ancestry informative markers (AIMs), and test the association of IGA with diabetic nephropathy in the combined sample.

Results

A fixed parental allele maximum likelihood algorithm was applied to the FIND to estimate IGA in four samples: 869 American Indians; 1385 African Americans; 1451 Mexican Americans; and 826 European Americans. When the information in the AIMs is unbalanced, the estimates are incorrect with large error. Individual genetic admixture is highly correlated with principle components for capturing population structure. It takes ~700 SNPs to reduce the average standard error of individual admixture below 0.01. When the samples are combined, the resulting population structure creates associations between IGA and diabetic nephropathy.

Conclusions

The identified set of AIMs, which include American Indian parental allele frequencies, may be particularly useful for estimating genetic admixture in populations from the Americas. Failure to balance information in maximum likelihood, poly-ancestry models creates biased estimates of individual admixture with large error. This also occurs when estimating IGA using the Bayesian clustering method as implemented in the program STRUCTURE. Odds ratios for the associations of IGA with disease are consistent with what is known about the incidence and prevalence of diabetic nephropathy in these populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2654-x) contains supplementary material, which is available to authorized users.