Childhood Takayasu arteritis: disease course and response to therapy

Background

Takayasu arteritis (TAK) is a large vessel vasculitis that rarely affects children. Data on childhood TAK are scarce. The aim of this study was to analyze the presenting features, course and outcome of children with TAK, compare efficacy of treatment regimens and identify high-risk factors for adverse outcome.

Methods

A single-center cohort study of consecutive children fulfilling the EULAR/PRINTO/PReS criteria for childhood TAK between 1986 and 2015 was performed. Clinical phenotypes, laboratory markers, imaging features, disease course and treatment were documented. Disease activity was assessed using the Pediatric Vasculitis Disease Activity Score at each visit. Outcome: disease flare defined as new symptoms and/or increased inflammatory markers necessitating therapy escalation and/or new angiographic lesions, or death. Analysis: logistic regression tested relevant variables for flare. Kaplan-Meier analyses compared treatment regimens.

Results

Twenty-seven children were included; 74% were female, median age at diagnosis was 12.4 years. Twenty-two (81%) children presented with active disease at diagnosis. Treatment regimens included corticosteroids alone (15%), corticosteroids plus methotrexate (37%), cyclophosphamide (19%), or a biologic agent (11%). Adverse outcomes were documented in 14/27 (52%) children: two (7%) died within 6 months of diagnosis, and 13 (48%) experienced disease flares. The 2-year flare-free survival was 80% with biologic treatments compared to 43% in non-biologic therapies (p = 0.03); at last follow-up, biologic therapies resulted in significantly higher rates of inactive disease (p = 0.02). No additional outcome predictor was identified.

Conclusions

Childhood TAK carries a high disease burden; half of the children experienced flares and 7% died. Biologic therapies were associated with better control of disease activity.

Incidence and risk factors of early surgical complications in young renal transplant recipients: A persistent challenge

There is a paucity of data on the rate of urological and vascular complications in very young children after kidney transplant. We conducted a study on the incidence and risk factors for early post-transplant surgical complications in young recipients (<5 years) over three decades. The primary outcome was any urological or vascular complication within 30 days of transplant, and the secondary outcome was incidence rate of graft failure reported as per 1000 person-years. Risk factors associated with surgical complications were analyzed by logistic regression. There were 22 (26.5%) complications in 21 children with vascular thrombosis being the most common complication. There was no significant difference in the number of complications in period 1 (1985-1994) and period 2 (1995-2014) (P=.1). The incidence rate of graft failure was higher in period 1 (IR 70.8, 95% CI 41.1, 121.9) compared to period 2 (IR 20.7, 95% CI 9.3, 46.0). Cumulative incidence of graft survival at 1, 3, and 5 years' post-transplant was 96.5%, 92.6%, and 90%, respectively, in those without compared to 71%, 65.1%, and 58.6%, respectively, in children with complications. In conclusion, early surgical, especially vascular, complications are quite common in young renal transplant recipients and lead to significantly reduced graft survival.

A Toddler Presenting with Pulmonary Renal Syndrome

Pulmonary renal syndrome refers to an association of pulmonary and glomerular disease and includes disorders, such as the ANCA-associated vasculitides, anti-glomerular basement membrane antibody disease, systemic lupus erythematosus, and IgA vasculitis (Henoch-Schönlein purpura). We present the medical history of a 26-month-old boy with an extensive purpuric rash, involving the limbs, trunk, and face, who developed clinically significant pulmonary hemorrhage and renal involvement. Rapid recognition of this rare but potentially life-threatening condition is crucial. In this report, we discuss the differential diagnosis, diagnostic studies, and treatment options to consider when facing a young child presenting with a pulmonary renal syndrome.

Responsiveness of the PROMIS® measures to changes in disease status among pediatric nephrotic syndrome patients: a Midwest pediatric nephrology consortium study

BACKGROUND

Nephrotic syndrome represents a condition in pediatric nephrology typified by a relapsing and remitting course, proteinuria and the presence of edema. The PROMIS measures have previously been studied and validated in cross-sectional studies of children with nephrotic syndrome. This study was designed to longitudinally validate the PROMIS measures in pediatric nephrotic syndrome.

METHODS

One hundred twenty seven children with nephrotic syndrome between the ages of 8 and 17 years participated in this prospective cohort study. Patients completed a baseline assessment while their nephrotic syndrome was active, a follow-up assessment at the time of their first complete proteinuria remission or study month 3 if no remission occurred, and a final assessment at study month 12. Participants completed six PROMIS measures (Mobility, Fatigue, Pain Interference, Depressive Symptoms, Anxiety, and Peer Relationships), the PedsQL version 4.0, and two global assessment of change items.

RESULTS

Disease status was classified at each assessment: nephrotic syndrome active in 100% at baseline, 33% at month 3, and 46% at month 12. The PROMIS domains of Mobility, Fatigue, Pain Interference, Depressive Symptoms, and Anxiety each showed a significant overall improvement over time (p < 0.001). When the PROMIS measures were compared to the patients' global assessment of change, the domains of Mobility, Fatigue, Pain Interference, and Anxiety consistently changed in an expected fashion. With the exception of Pain Interference, change in PROMIS domain scores did not correlate with changes in disease activity. PROMIS domain scores were moderately correlated with analogous PedsQL domain scores.

CONCLUSION

This study demonstrates that the PROMIS Mobility, Fatigue, Pain Interference, and Anxiety domains are sensitive to self-reported changes in disease and overall health status over time in children with nephrotic syndrome. The lack of significant anchoring to clinically defined nephrotic syndrome disease active and remission status may highlight an opportunity to improve the measurement of HRQOL in children with nephrotic syndrome through the development of a nephrotic syndrome disease-specific HRQOL measure.

Parental Health Literacy and Outcomes of Childhood Nephrotic Syndrome

OBJECTIVE

Determine the association of parental health literacy with treatment response among children with nephrotic syndrome.

METHODS

This was a cohort study of children aged 1-18 with nephrotic syndrome and their parent. Health literacy was measured using the validated Short Test of Functional Health Literacy in Adults assessing reading comprehension and numeracy. Outcomes included initial relapse-free period, frequently relapsing disease, relapse rate, second-line medication use, and complete remission after therapy.

RESULTS

Of 190 parents, 80% had adequate health literacy (score >67 of 100), and higher scores were not correlated with higher education. Almost all achieved perfect numeracy scores (>86%); numeracy was not associated with outcomes. After adjusting for immigration, education, and income, higher reading comprehension scores (tertile 3) compared with lower scores (tertile 1) were significantly associated with lower risk of first relapse (hazard ratio 0.67, 95% confidence interval [CI] 0.48-0.94, P trend = .02), lower odds of frequently relapsing disease (odds ratio [OR] 0.38, 95% CI 0.21-0.70, P trend = .002), lower relapse rate (rate ratio 0.77, 95% CI 0.73-0.80, P trend < .001), and higher odds of complete remission after both initial steroids and cyclophosphamide (OR 2.07, 95% CI 1.36-3.16, P trend = .003; OR 5.97, 95% CI 2.42-14.7, P trend < .001).

CONCLUSIONS

Lower parental health literacy, specifically reading comprehension, is associated with higher relapse rates among children with nephrotic syndrome and fewer achieving complete remission. This underscores the importance of assessing and targeting health literacy for chronic management of childhood-onset diseases.

Ethnic Differences in Incidence and Outcomes of Childhood Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Ethnic differences in outcomes among children with nephrotic syndrome are unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a longitudinal study at a single regional pediatric center comparing ethnic differences in incidence from 2001 to 2011 census data and longitudinal outcomes, including relapse rates, time to first relapse, frequently relapsing disease, and use of cyclophosphamide. Among 711 children, 24% were European, 33% were South Asian, 10% were East/Southeast Asian, and 33% were of other origins.

RESULTS

Over 10 years, the overall incidence increased from 1.99/100,000 to 4.71/100,000 among children ages 1-18 years old. In 2011, South Asians had a higher incidence rate ratio of 6.61 (95% confidence interval, 3.16 to 15.1) compared with Europeans. East/Southeast Asians had a similar incidence rate ratio (0.76; 95% confidence interval, 0.13 to 2.94) to Europeans. We determined outcomes in 455 children from the three largest ethnic groups with steroid-sensitive disease over a median of 4 years. South Asian and East/Southeast Asian children had significantly lower odds of frequently relapsing disease at 12 months (South Asian: adjusted odds ratio; 0.55; 95% confidence interval, 0.39 to 0.77; East/Southeast Asian: adjusted odds ratio; 0.42; 95% confidence interval, 0.34 to 0.51), fewer subsequent relapses (South Asian: adjusted odds ratio; 0.64; 95% confidence interval, 0.50 to 0.81; East/Southeast Asian: adjusted odds ratio; 0.47; 95% confidence interval, 0.24 to 0.91), lower risk of a first relapse (South Asian: adjusted hazard ratio, 0.74; 95% confidence interval, 0.67 to 0.83; East/Southeast Asian: adjusted hazard ratio, 0.65; 95% CI, 0.63 to 0.68), and lower use of cyclophosphamide (South Asian: adjusted hazard ratio, 0.82; 95% confidence interval, 0.53 to 1.28; East/Southeast Asian: adjusted hazard ratio, 0.54; 95% confidence interval, 0.41 to 0.71) compared with European children.

CONCLUSIONS

Despite the higher incidence among South Asians, South and East/Southeast Asian children have significantly less complicated clinical outcomes compared with Europeans.

Arterial dissection in childhood Takayasu Arteritis: not as rare as thought

BACKGROUND

Arterial vessel wall dissection is a rare, life-threatening and rarely described complication in childhood Takayasu Arteritis (cTA). Prevalence and risk factors for arterial dissection in cTA are unknown. We sought to study the prevalence and analyse risk factors for arterial dissection in cTA.

FINDINGS

A single center retrospective review of all children with cTA was performed. Patients with arterial dissection at cTA diagnosis were reported in detail and compared to the remaining single center retrospective cohort of children without dissection. Disease activity was assessed by the Pediatric Vasculitis Disease Activity Score (PVAS). A total of 27 cTA patients (74 % girls) were included. Three children (11 %) presented with dissection at diagnosis of cTA. They had higher PVAS (median 21 versus 10, p = 0.26), increased neutrophils (p < 0.0001) and lower albumin levels (p = 0.05). Arterial hypertension was common in both groups: in 67 % of children with dissection and 54 % of those without.

CONCLUSIONS

Arterial dissection was more frequent in our cTA cohort than previously reported. Careful vascular imaging assessment is crucial to document this complication. High disease activity and markers of inflammation especially in combination with arterial hypertension, may be associated with the risk for vessel wall dissection in children with cTA.

Parental attitudes to genetic testing differ by ethnicity and immigration in childhood nephrotic syndrome: a cross-sectional study

Background

Studies in the USA report differences in opinion among parents of different ethnic groups toward genetic testing for their child; however, there are no studies that address this issue in the diverse ethnic and immigrant population in Canada.

Objective

This study aims to determine whether ethnicity and immigration status influences parental interest in clinical genetic testing for a potentially progressive kidney disease.

Design

This is a cross-sectional study.

Setting

Participants were recruited from the Greater Toronto Area, Canada.

Participants

The study included 320 parents of children ages 1–18 years with nephrotic syndrome enrolled in the Insight into Nephrotic Syndrome: Investigating Genes, Health and Therapeutics (INSIGHT) observational cohort study.

Measurements

Demographic, ethnicity, immigration, and child specific factors as well as interest in genetic testing were collected through self-reported questionnaires administered at baseline study visit.

Methods

Logistic regression models were used to examine association of ethnicity and immigration status with interest in genetic testing.

Results

The majority of parents (85 %) were interested in genetic testing for their child. South Asian and East/Southeast Asian parents had 74 and 76 % lower odds of agreeing to genetic testing when compared to Europeans (odds ratio (OR) 0.26, 95 % confidence interval (CI) 0.10–0.68; OR 0.24, 95 % CI 0.07–0.79, respectively) after controlling for age and sex of child, age and education level of parent, initial steroid resistance, and duration of time in Canada. Immigrants to Canada also had significantly lower odds (OR 0.29, 95 % CI 0.12–0.72) of agreeing to genetic testing after similar adjustment. Higher education level was not associated with greater interest in genetic testing (OR 1.24, 95 % CI 0.64–2.42).

Limitations

Participants have already agreed to aggregate genetic testing for research purposes as part of enrolment in INSIGHT study.

Conclusion

While majority of parents were interested in genetic testing for their child, immigrants, particularly South Asians and East/Southeast Asians, were more likely to decline genetic testing. Genetic counseling needs to be tailored to address specific concerns in these parental groups to maximize informed decision-making in the clinical setting.

Trial registration

ClinicalTrials.gov, NCT01605266

Lacosamide cardiac safety: clinical trials in patients with partial-onset seizures

OBJECTIVE

To evaluate the cardiac safety of adjunctive lacosamide in a large pool of adults with partial-onset seizures (POS).

METHODS

Post-randomization changes from baseline for electrocardiographic (ECG) measurements, diagnostic findings, and relevant adverse events (AEs) were compared for pooled data from three randomized, placebo-controlled trials of adjunctive lacosamide for the treatment of POS.

RESULTS

Lacosamide did not prolong the QTc interval or affect heart rate as determined by an analysis of data from patients randomized to lacosamide 200, 400, or 600 mg/day (n = 944) compared with placebo (n = 364). After 12-week maintenance treatment, mean changes from baseline for QRS duration were similar between the placebo and lacosamide 200 and 400 mg/day groups (0.0, -0.2, and 0.4 ms), but slightly increased for lacosamide 600 mg/day (2.3 ms). A small, dose-related mean increase in PR interval was observed (-0.3, 1.4, 4.4, and 6.6 ms for the placebo and lacosamide 200, 400, and 600 mg/day groups, respectively). First-degree atrioventricular (AV) block was reported as a non-serious AE in 0.0%, 0.7%, 0.2%, and 0.5% of patients in the same respective groups. Second- or higher degree AV block was not observed. There was no evidence of a PR-interval-related pharmacodynamic interaction of lacosamide with either carbamazepine or lamotrigine.

CONCLUSIONS

Evaluation of the pooled cardiac safety data from patients with POS showed that adjunctive lacosamide at the maximum recommended dose (400 mg/day) was not clearly associated with any cardiac effect other than a small, dose-related increase in PR interval that had no evident symptomatic consequence.

Whole mount immunofluorescence analysis of placentas from normotensive versus preeclamptic pregnancies

INTRODUCTION

Defects in placental angiogenesis and spiral artery remodeling have been proposed to play essential roles in the development of preeclampsia. However, the specific molecular mechanism(s) responsible for aberrant placental angiogenesis in preeclampsia are incompletely understood. The vascular endothelial growth factor receptors (VEGFR1, R2, R3) and STAT3 have critical functions in normal blood vessel development, but their potential roles in preeclampsia are currently unclear. In this study, we utilized a novel whole mount immunofluorescence (WMIF) method to compare expression of VEGFR1, R2, R3 and activated, phosphorylated STAT3 (pSTAT3) in placentas of preeclamptic (PE) versus normotensive (NT) pregnancies.

METHODS

Placental biopsies collected from NT and PE pregnant women were fixed and stained with fluorochrome-conjugated antibodies to identify specific cell populations as follows: CD31 for blood vessel endothelial cells, cytokeratin-7 for trophoblast cells, and CD45 for immune cells. Expression of the VEGFRs and pSTAT3 were subsequently characterized by WMIF in conjunction with confocal microscopy.

RESULTS

A total of 18 PE and 18 NT placentas were evaluated. No significant differences in the cell type-specific expression patterns or expression levels of VEGFR1, VEGFR2 or VEGFR3 were detected between NT and PE placentas. In contrast, statistically significant increases in pSTAT3 staining were detected in endothelial cells of PE placentas versus NT controls.

DISCUSSION

Our study demonstrates that increased pSTAT3 expression in placental endothelial cells is associated with PE. We speculate that elevated pSTAT3 expression in the blood vessels of PE placentas may be due to aberrant angiogenesis, increased pro-inflammatory cytokine expression, and/or placental stress.

The impact of disease duration on quality of life in children with nephrotic syndrome: a Midwest Pediatric Nephrology Consortium study

BACKGROUND

The Patient Reported Outcomes Measurement Information System (PROMIS) II is a prospective study that evaluates patient reported outcomes in pediatric chronic diseases as a measure of health-related quality of life (HRQOL). We have evaluated the influence of disease duration on HRQOL and, for the first time, compared the findings of the PROMIS measures to those of the PedsQL™ 4.0 Generic Scales (PedsQL) from the PROMIS II nephrotic syndrome (NS) longitudinal cohort.

METHODS

This was a prospective study in which 127 children (age range 8-17 years) with active NS from 14 centers were enrolled. Children with active NS defined as the presence of nephrotic range proteinuria (>2+ urinalysis and edema or urine protein/creatinine ratio >2 g/g) were eligible. Comparisons were made between children with prevalent (N = 67) and incident (N = 60) disease at the study enrollment visit.

RESULTS

The PROMIS scores were worse in prevalent patients in the domains of peer relationship (p = 0.01) and pain interference (p < 0.01). The PedsQL showed worse scores in prevalent patients for social functioning (p < 0.01) and school functioning (p = 0.03). Multivariable analyses showed that prevalent patients had worse scores in PROMIS pain interference (p = 0.02) and PedsQL social functioning (p < 0.01).

CONCLUSION

The PROMIS measures detected a significant impact of disease duration on HRQOL in children, such that peer relationships were worse and pain interfered with daily life to a greater degree among those with longer disease duration. These findings were in agreement with those for similar domains in the PedsQL legacy instrument.

Cytomegalovirus in pediatric systemic lupus erythematosus: prevalence and clinical manifestations

Cytomegalovirus (CMV) is a beta-herpesvirus and antibodies to this virus are common in patients with systemic lupus erythematosus (SLE). However, few studies have examined the relationship between CMV infection and SLE.

OBJECTIVES

Our objectives were: 1) to determine the prevalence of CMV infection at the time of SLE diagnosis, and 2) to determine the risk factors for CMV infection.

METHODS

A database review of 670 patients with pediatric SLE (pSLE) seen over a 20-year period identified seven patients with a CMV infection detected at the time of diagnosis of SLE. CMV was diagnosed by serology, urine and bronchoalveolar lavage. Clinical manifestations, laboratory findings, virology studies and treatments were reviewed.

RESULTS

CMV infection was detected in seven patients at the time of SLE diagnosis (1.04% of total cohort): six were female: mean age was 13 years. Predominant features included non-Caucasian ethnicity (p < 0.01 as compared to total SLE cohort), persistent fevers on prednisone in seven and nephrotic syndrome in four. Laboratory findings included: anemia in seven, lymphopenia in five, elevated liver enzymes in four, with anti-dsDNA and anti-RNP antibodies present in six and five, respectively. Six patients received ganciclovir and CMV hyperimmune globulin (Cytogam®) with the continuation of prednisone during CMV treatment. Six of seven fully recovered without sequelae (one without treatment) but one patient died with active CMV infection.

CONCLUSIONS

There were 1.04% of patients with pSLE who developed CMV infection. All were of non-Caucasian ethnicity. Persistent fever despite prednisone, with concomitant anemia, may be additional clues to CMV infection in pSLE. We suggest all patients have routine testing for CMV immunity at initial presentation of pSLE.

The new histopathologic classification of ANCA-associated GN and its association with renal outcomes in childhood

BACKGROUND AND OBJECTIVES

A proposed histopathologic classification for ANCA-associated GN is predictive of long-term renal outcome in adult populations. This study sought to validate this system in a pediatric cohort.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective, single-center, cohort study of 40 children diagnosed and followed until their transition to adult care at one institution between 1987 and 2012. Renal biopsy specimens were reviewed by a pathologist blinded to patient outcome and were classified using the new histopathologic classification system of focal, crescentic, mixed, and sclerotic groups. Time to the composite outcome of CKD stages 3 and 4 (determined by eGFR with repeated creatinine measures using the Schwartz equation) or ESRD (defined as dialysis dependence or transplantation) were ascertained.

RESULTS

The study population consisted of 40 children (70% female), followed for a median of 2.4 years. The biopsy specimens were categorized as focal in 13 patients (32.5%), crescentic in 20 (50%), mixed in two (5%), and sclerotic in five (12.5%). Mixed and crescentic were combined for analyses. Survival analysis of time to the composite renal endpoint of at least 3 months of eGFR<60 ml/min per 1.73 m(2) or ESRD differed significantly among the three biopsy groups log-rank P<0.001), with an adjusted hazard ratio of 3.14 (95% confidence interval, 0.68 to 14.4) in the crescentic/mixed group and 23.6 (95% confidence interval, 3.9 to 144.2) in the sclerotic category compared with the focal category. The probability of having an eGFR>60 ml/min per 1.73 m(2) at 2 years was 100% for the focal, 56.5% for the crescentic/mixed, and 0% for the sclerotic biopsy categories.

CONCLUSIONS

This study showed the clinical utility of this histopathologic classification system and its ability to discriminate renal outcomes among children with ANCA GN.

Skeletal findings in the first 12 months following initiation of glucocorticoid therapy for pediatric nephrotic syndrome

Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point.

INTRODUCTION

Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome.

METHODS

VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry.

RESULTS

Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017).

CONCLUSIONS

The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.

The rationale and design of Insight into Nephrotic Syndrome: Investigating Genes, Health and Therapeutics (INSIGHT): a prospective cohort study of childhood nephrotic syndrome

BACKGROUND

Nephrotic syndrome is one of the most commonly diagnosed kidney diseases in childhood and its progressive forms can lead to chronic kidney disease (CKD) and/or end-stage renal disease (ESRD). There have been few longitudinal studies among a multi-ethnic cohort to determine potential risk factors influencing disease susceptibility, treatment response, and progression of nephrotic syndrome. Temporal relationships cannot be studied through cross-sectional study design. Understanding the interaction between various factors is critical to developing new strategies for treating children with kidney disease. We present the rationale and the study design of a longitudinal cohort study of children with nephrotic syndrome, the Insight into Nephrotic Syndrome: Investigating Genes, Health and Therapeutics (INSIGHT) study. The specific aims are to determine: 1) socio-demographic, environmental, and genetic factors that influence disease susceptibility; 2) rates of steroid treatment resistance and steroid treatment dependence, and identify factors that may modify treatment response; 3) clinical and genetic factors that influence disease susceptibility and progression to CKD and ESRD; and 4) the interaction between the course of illness and socio-demographic, environmental, and clinical risk factors.

METHODS/DESIGN

INSIGHT is a disease-based observational longitudinal cohort study of children with nephrotic syndrome. At baseline, participants complete questionnaires and provide biological specimen samples (blood, urine, and toenail clippings). Follow-up questionnaires and repeat biological specimen collections are performed annually for up to five years.

DISCUSSION

The proposed cohort will provide the structure to test various risk factors predicting or influencing disease susceptibility, treatment response, and progression to CKD among children with nephrotic syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01605266.

Note: digital optical zoom by selection of polarization

The combination of a liquid crystal cell with a polarizing beam splitter is used to select one of the two paths through an optical imaging system. The paths both focus the same image on a CCD detector, but one has 4 times the magnification of the other.