A Prospective Natural History Study of Mucopolysaccharidosis Type IIIA

OBJECTIVES

To characterize the clinical course of mucopolysaccharidosis type IIIA (MPS IIIA), and identify potential endpoints for future treatment trials.

STUDY DESIGN

Children with a confirmed diagnosis of MPS IIIA, functioning above a developmental age of 1 year, were followed for up to 2 years. Cognitive status and brain atrophy were assessed by standardized tests and volumetric magnetic resonance imaging, respectively. Liver and spleen volumes and cerebrospinal fluid and urine biomarker levels were measured.

RESULTS

Twenty-five children, from 1.1 to 18.4 years old, were enrolled, and 24 followed for at least 12 months. 19 exhibited a rapidly progressing (RP) form of MPS IIIA, and 5, a more slowly progressing form. Children with RP plateaued in development by 30 months, followed by rapid regression after 40-50 months. In patients with RP, cognitive developmental quotients showed consistent steep declines associated with progressive cortical gray matter atrophy. Children with slowly progressing had a similar but more prolonged course. Liver and spleen volumes were approximately double normal size, and cerebrospinal fluid and urine heparin sulfate levels were elevated and relatively constant over time.

CONCLUSION

Developmental quotient and cortical gray matter volume are sensitive markers of disease progression in MPS IIIA, and may have utility as clinical endpoints in treatment trials. For optimal outcomes, treatment may need to be instituted in children before the onset of steep cognitive decline and brain atrophy.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01047306.

Depression, Anxiety, and Severity of Obesity in Adolescents: Is Emotional Eating the Link?

The purposes of this study were to characterize the impact of depression and anxiety on the severity of obesity among youth seeking weight management treatment and to determine the extent to which emotional eating mediates the relationship between depression and/or anxiety and degree of obesity. This cross-sectional, retrospective chart review of 102 adolescent patients from a weight management clinic analyzed demographics, body mass index, depression (Patient Health Questionnaire-9), and anxiety (Generalized Anxiety Disorder Scale-7) screens and the Child Eating Behavior Questionnaire, Emotional Over-Eating subscale. After adjusting for demographics and emotional eating, the odds of having severe obesity versus obesity were 3.5 times higher for patients with depression compared with those without (odds ratio [OR] = 3.5; 95% CI = 1.1, 11.3; P = .038) and nearly 5 times higher for those with anxiety (OR = 4.9; CI = 1.2, 20.9; P = .030). Emotional eating, however, was not a mediator between depression/anxiety and degree of adiposity.

Neurocognition across the spectrum of mucopolysaccharidosis type I: Age, severity, and treatment

OBJECTIVES

Precise characterization of cognitive outcomes and factors that contribute to cognitive variability will enable better understanding of disease progression and treatment effects in mucopolysaccharidosis type I (MPS I). We examined the effects on cognition of phenotype, genotype, age at evaluation and first treatment, and somatic disease burden.

METHODS

Sixty patients with severe MPS IH (Hurler syndrome treated with hematopoietic cell transplant and 29 with attenuated MPS I treated with enzyme replacement therapy), were studied with IQ measures, medical history, genotypes. Sixty-seven patients had volumetric MRI. Subjects were grouped by age and phenotype and MRI and compared to 96 normal controls.

RESULTS

Prior to hematopoietic cell transplant, MPS IH patients were all cognitively average, but post-transplant, 59% were below average, but stable. Genotype and age at HCT were associated with cognitive ability. In attenuated MPS I, 40% were below average with genotype and somatic disease burden predicting their cognitive ability. White matter volumes were associated with IQ for controls, but not for MPS I. Gray matter volumes were positively associated with IQ in controls and attenuated MPS I patients, but negatively associated in MPS IH.

CONCLUSIONS

Cognitive impairment, a major difficulty for many MPS I patients, is associated with genotype, age at treatment and somatic disease burden. IQ association with white matter differed from controls. Many attenuated MPS patients have significant physical and/or cognitive problems and receive insufficient support services. Results provide direction for future clinical trials and better disease management.

Risk of lymphoma after renal transplantation varies with time: an analysis of the United States Renal Data System

BACKGROUND

Characterization of the incidence of posttransplant lymphoma over time may help guide the timing and intensity of posttransplant monitoring. We analyzed the United States Renal Data System to describe the occurrence of lymphoma following renal transplantation.

METHODS

All end-stage renal disease patients placed on the transplant waiting list between January 1, 1990 and December 31, 1999 were considered. Survival analysis was used to estimate lymphoma risk in renal transplant patients.

RESULTS

Of 89,260 eligible patients, a total of 556 lymphoma cases were identified with 357 in transplant patients. The overall rate of posttransplant lymphoma was 33.3/10,000 person-years in transplant patients. There was variation in the duration and magnitude of increased lymphoma risk by age. The highest rates of lymphoma were among transplanted patients in the first 12 months, after which the rate of lymphoma decreased. Among Caucasian transplant recipients less than 25 years of age, the adjusted relative risk of lymphoma ranged from 13.82 [95% CI: (3.96, 48.15)] within 6 months posttransplant to 3.46 [95% CI: (0.69, 17.44)] within months 30-36 posttransplant. Only patients under 25 years had a notably increased risk beyond the first 2 posttransplant years. The risk of lymphoma differed by race, with Caucasian patients at nearly double the risk of African-Americans. Gender was not associated with lymphoma incidence.

CONCLUSIONS

We found and quantified a time-varying relationship between renal transplant and lymphoma risk. This information can be used in combination with knowledge of established risk factors to guide the schedule of posttransplant monitoring.

Transcranial direct current stimulation and constraint-induced therapy in cerebral palsy: A randomized, blinded, sham-controlled clinical trial

We investigated the safety, feasibility, and efficacy of transcranial direct current stimulation (tDCS) combined with constraint-induced movement therapy (CIMT) in children and young adults with unilateral cerebral palsy. Twenty participants were randomized to receive active or sham tDCS. The intervention consisted of 10 consecutive weekday sessions of tDCS applied to the non-lesioned hemisphere (20 min) concurrently with CIMT (120 min). Participants, caregivers, and interventionists were blinded to group assignment. The primary safety outcome investigated adverse events. The primary behavioral outcome was the Assisting Hand Assessment. All 20 participants (mean age = 12.7 yrs, range = 7.4-21.6 years) were evaluated for the primary outcomes. No serious adverse events occurred, and the most commonly reported minor adverse events were headache and itchiness. Both groups demonstrated a significant improvement in hand function after the intervention, although no significant effect of tDCS was observed (between-group difference = -2.18, 95% CI = [-6.48, 2.12], p = 0.30). Although hand function improved overall, no significant differences between intervention groups were found. Children with preserved corticospinal tract circuitry from the lesioned hemisphere, compared to those without, showed greater improvement in hand function (mean difference = 3.04, 95% CI = [-0.64, 6.72], p = 0.099). Our study demonstrates the safety and feasibility of serial sessions of tDCS, and presents preliminary evidence for the effect of CST circuitry on outcomes following tDCS/CIMT. Future work in children with unilateral cerebral palsy should focus on the optimal dosing and consider individual brain circuitry when describing response to combined interventions.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.govNCT 02250092.

Pain severity and neuropathic pain symptoms in primary Sjögren's syndrome: a comparison study of seropositive and seronegative Sjögren's syndrome patients

OBJECTIVE

To compare clinical characteristics and patient-reported outcomes in seropositive versus seronegative primary Sjögren's syndrome (SS) patients and to investigate the effect of serologic status on the prevalence of chronic pain, comorbidity, and health quality.

METHODS

Pain severity and neuropathic pain symptoms, comorbidity, and health status were assessed in 108 primary SS patients. Differences between patient groups were assessed by t-test and chi-square test, as well as adjusted pain-affect associations. The effect of predictor variables on pain severity was examined with multivariate regression.

RESULTS

Pain severity was greater (P = 0.003) and physical function (P = 0.023) was reduced in the seronegative patients. Prevalence of neuropathic pain, depression, anxiety, and disability was similar between groups. Chronic pain, defined as daily pain for >3 months, was reported by 65% of seropositive (n = 65) and 75% of seronegative (n = 40) patients. After adjustment for age, sleep quality, and psychological distress, the difference in pain severity between seropositive and seronegative patients remained significant.

CONCLUSION

Chronic pain is pervasive in both seropositive and seronegative primary SS patients, while pain severity and functional impairment are greater in seronegative patients. Neuropathic pain is equally prevalent and is the predominant pain phenotype in patients with moderate to severe pain. Accurate assessment of pain phenotypes is needed for more effective management of chronic pain in primary SS. The focus of future research should be to standardize assessment of pain and to identify the factors contributing to more severe pain in seronegative patients.

Racial and ethnic differences in incident myocardial infarction in end-stage renal disease patients: The USRDS

African Americans have a greater risk of cardiovascular disease (CVD) than Caucasians in early chronic kidney disease; however, limited data describe racial and ethnic differences in the risk of incident myocardial infarction (MI) among patients with end-stage renal disease (ESRD). We conducted a prospective, observational cohort study among 271 102 incident dialysis patients receiving renal replacement therapy enrolled in the United States Renal Data System (USRDS) for whom Medicare was the primary insurer between 1995 and 2000. The incidence and risk of any MI (non-fatal or fatal) estimated by Cox proportional hazards models was the primary outcome of interest. Of those with prevalent CVD at baseline (118 708), 14 849 had an incident non-fatal MI compared with 9926 events for those without prevalent CVD (152 394). Patients with prevalent CVD had higher crude rates of combined fatal and non-fatal MI (99.3/1000 person-years vs 42.9/1000 person-years) compared with those without prevalent CVD. Among those with prevalent CVD, African Americans (adjusted relative risk (aRR)=0.65, 95% confidence interval (CI):0.62-0.68), Asian Americans (aRR=0.74, 95% CI: 0.66-0.83), and Hispanics (aRR=0.72, 95% CI: 0.68-0.77) were 26-35% less likely to have an incident MI compared to Caucasians. Similarly, among those without prevalent CVD, racial/ethnic minorities were 26-42% less likely to have an incident MI compared to Caucasians. We conclude that in a national setting where comparable access to dialysis and associated medical care, exist, racial/ethnic minorities were found to have a lower risk of non-fatal and fatal MI than Caucasians.

Distinct progression patterns of brain disease in infantile and juvenile gangliosidoses: Volumetric quantitative MRI study

BACKGROUND

GM1-gangliosidosis and GM2-gangliosidosis (Tay-Sachs disease and Sandhoff disease) are unrelenting heritable neurodegenerative conditions of lysosomal ganglioside accumulation. Although progressive brain atrophy is characteristic, longitudinal quantification of specific brain structures has not been systematically studied.

OBJECTIVES

The goal of this longitudinal study has been to quantify and track brain MRI volume changes, including specific structure volume changes, at different times in disease progression of childhood gangliosidoses, and to explore quantitative brain MRI volumetry (qMRI) as a non-invasive marker of disease progression for future treatment trials.

METHODS

Brain qMRI studies were performed in 14 patients with gangliosidoses (9 infantile, 5 juvenile) yearly. Cerebellar cortex and white matter, caudate, putamen, corpus callosum, ventricles, total brain, and intracranial volumes were measured, as well as total brain volume. Age-matched controls were available for the patients with the juvenile phenotype.

RESULTS

The infantile phenotype of all gangliosidoses showed a consistent pattern of macrocephaly and rapidly increasing intracranial MRI volume with both (a) brain tissue volume (cerebral cortex and other smaller structures) and (b) ventricular volume (P<0.01 for all). In contrast to apparent enlargement of the total brain volume, and chiefly the enlarged cerebral cortex, a subset of smaller brain substructures generally decreased in size: the corpus callosum, caudate and putamen became smaller with time. The volume of cerebellar cortex also decreased in patients with infantile GM1-gangliosidosis and juvenile GM1- and GM2-gangliosidosis; however, infantile GM2-gangliosidosis cerebellar cortex was the exception, increasing in size. Elevated intracranial pressure (estimated by lumbar spinal pressure) was a common finding in infantile disease and showed continued increases as the disease progressed, yet lacked MRI signs of hydrocephalus except for increasing ventricular size. Notably, in patients with juvenile gangliosidosis, macrocephaly and elevated intracranial pressure were absent and total brain volume decreased with time compared to controls (P=0.004).

CONCLUSIONS

The disease course of infantile versus juvenile gangliosidoses is clearly distinguished by the rate of brain disease progression as characterized by qMRI. Assessments by qMRI represent a robust non-invasive method for monitoring CNS changes in the clinical course of gangliosidoses and is ideally suited to monitor effects of novel CNS-directed therapies in future clinical trials.

The Neurobehavioral Phenotype in Mucopolysaccharidosis Type IIIB: an Exploratory Study

OBJECTIVES

Our goal was to describe the neurobehavioral phenotype in mucopolysaccharidosis Type IIIB (MPS IIIB). Parents report that behavioral abnormalities are a major problem in MPS III posing serious challenges to parenting and quality-of-life for both patient and parent. Our previous research on MPS IIIA identified autistic symptoms, and a Klüver-Bucy-type syndrome as indicated by reduced startle and loss of fear associated with amygdala atrophy. We hypothesized that MPS IIIB would manifest similar attributes when assessed with the same neurobehavioral protocol.

METHODS

Ten patients with MPS IIIB were compared with 9 MPS IIIA patients, all older than 6. 8 younger children with Hurler syndrome (1H) were chosen as a comparison group for the Risk Room procedure; MPS IH does not directly affect social/emotional function and these younger children were closer to the developmental level of the MPS IIIB group. To examine disease severity, cognitive ability was assessed. Four evaluations were used: the Risk Room procedure (to measure social-emotional characteristics, especially fear and startle responses), the Autism Diagnostic Observation Schedule (ADOS), the Sanfilippo Behavior Rating Scale (SBRS), and amygdala brain volumes calculated from manually-traced MRI images.

RESULTS

The two groups are equivalent in severity and show severe cognitive impairment. On the ADOS, the MPS IIIB patients exhibited the same autistic features as IIIA. The IIIB means differed from MPS IH means on most measures. However, the IIIB group did not approach the Risk Room stranger, like the MPS IH group who kept their distance, but unlike the IIIA group who showed no fear of the stranger. On the SBRS, the MPS IIIB patients were described as more inattentive and more fearful, especially of new people than the MPS IIIA. Onsets of some disease characteristics appeared more closely spaced and slightly earlier in MPS IIIB than IIIA.

CONCLUSIONS

On most behavioral measures, MPS IIIB patients did not differ substantially from MPS IIIA patients over age six, demonstrating autistic features and a Klüver Bucy-like syndrome including lack of fear and poor attention. Delay in onset of behavioral symptoms was associated with later diagnosis in two patients. Lack of fear, poor attention, and autistic-like symptomatology are as characteristic of MPS IIIB as they are of MPS IIIA. A possible difference is that the some behavioral abnormalities develop more quickly in MPS IIIB, If this is so, these patients may become at risk for harm and present a challenge for parenting even earlier than do those with MPS IIIA. .In future clinical trials of new treatments, especially with respect to quality of life and patient management, improvement of these behaviors will be an essential goal. Because very young patients were not studied, prospective natural history documentation of the early development of abnormal behaviors in MPS IIIB is needed.

Acquired autistic behaviors in children with mucopolysaccharidosis type IIIA

OBJECTIVES

To assess autism spectrum disorder (ASD) behaviors in children with mucopolysaccharidosis type IIIA (MPS IIIA) using a standard measure, understand the behavioral evolution of the disease, and provide specific guidelines for diagnosis.

STUDY DESIGN

Children (n = 21) with documented enzyme deficiency and SGSH gene mutations, cognitive age-equivalent >12 months, and early onset were administered the Autism Diagnostic Observation Schedule (ADOS) (module 1) and Bayley Scales of Infant Development-Third Edition. ADOS Social Affect and Restricted Repetitive Behavior total scores, as well as Bayley Scales of Infant Development-Third Edition cognitive age-equivalent scores, are reported using descriptive statistics and graphic presentations.

RESULTS

Thirteen of the 21 children evaluated met the ADOS criteria for ASD/autism. ADOS score was strongly associated with age; all 11 children aged >46 months met the criteria, compared with only 2 of 10 aged <46 months. Social and affective abnormalities were most frequent; restricted interests and repetitive behaviors were largely absent. Lack of cognitive growth paralleled ADOS score.

CONCLUSION

An increased incidence of ASD-like social behaviors was seen at age 3-4 years in children with early-onset MPS IIIA. Although more frequent in the severely impaired children, ASD-like behaviors were observed across the entire range of cognitive impairment. Clinicians must be aware that when a child acquires ASD-like behaviors, MPS IIIA should be included in the differential diagnosis.

Elevated TNF-α is associated with pain and physical disability in mucopolysaccharidosis types I, II, and VI

BACKGROUND

Children and adults with the lysosomal storage diseases mucopolysaccharidosis (MPS) types I, II and VI live shortened lives permeated by chronic pain and physical disability. Current treatments do not alleviate these problems. Thus there is a critical need to understand the mechanism of chronic pain and disability in MPS in order to improve the way we treat patients. A potential target is inflammation.

HYPOTHESIS

We hypothesized that excessive inflammation mediated by the tumor necrosis factor-α (TNF-α) inflammatory pathway is the fundamental cause of much of the chronic pain and physical disability in MPS.

METHODS

55 patients with MPS I, II, or VI were enrolled over the course of a 5-year prospective longitudinal natural history study and evaluated annually for 2-5years. 51 healthy controls were enrolled in a separate cross-sectional study of bone and energy metabolism. TNF-α was measured by ELISA. Pain and physical disability were measured by the Children's Health Questionnaire - Parent Form 50 (CHQ-PF50). Differences in log-transformed TNF-α levels and associations with CHQ domains were evaluated using a linear mixed effects model with random intercept.

RESULTS

TNF-α levels were measured in 48 MPS (age: 5-17years; 35% female) and 51 controls (age: 8-17years; 53% female). Among MPS, 22 (46%) were treated with hematopoietic cell transplantation (HCT) alone, 24 (50%) with enzyme replacement therapy (ERT) alone, and 2 (4%) with both HCT and ERT. TNF-α levels are higher in MPS compared to healthy controls (p<0.001). Higher TNF-α levels are associated with increased pain and decreased physical function, social limitations due to physical health, and physical summary score (all p<0.05). TNF-α levels were not significantly associated with the general health score. TNF-α levels did not change significantly over time in MPS.

CONCLUSIONS

Higher TNF-α levels are implicated in the pain and decreased physical function present in individuals with MPS despite treatment with ERT and/or HCT, suggesting that TNF-a inhibition could potentially be a useful adjunctive therapy. Further investigation into the role of TNF-α inhibition in MPS to decrease pain and improve physical function is indicated.

Unique white matter microstructural patterns in ADHD presentations-a diffusion tensor imaging study

Attention-deficit/hyperactivity disorder predominantly inattentive (ADHD-PI) and combined (ADHD-C) presentations are likely distinct disorders that differ neuroanatomically, neurochemically, and neuropsychologically. However, to date, little is known about specific white matter (WM) regions differentiating ADHD presentations. This study examined differences in WM microstructure using diffusion tensor imaging (DTI) data from 20 ADHD-PI, 18 ADHD-C, and 27 typically developed children. Voxel-wise analysis of DTI measurements in major fiber bundles was carried out using tract-based spatial statistics (TBSS). Clusters showing diffusivity abnormalities were used as regions of interest for regression analysis between fractional anisotropy (FA) and neuropsychological outcomes. Compared to neurotypicals, ADHD-PI children showed higher FA in the anterior thalamic radiations (ATR), bilateral inferior longitudinal fasciculus (ILF), and in the left corticospinal tract (CST). In contrast, the ADHD-C group exhibited higher FA in the bilateral cingulum bundle (CB). In the ADHD-PI group, differences in FA in the left ILF and ATR were accompanied by axial diffusivity (AD) abnormalities. In addition, the ADHD-PI group exhibited atypical mean diffusivity in the forceps minor (FMi) and left ATR and AD differences in right CB compared to healthy subjects. Direct comparison between ADHD presentations demonstrated radial diffusivity differences in FMi. WM clusters with FA irregularities in ADHD were associated with neurobehavioral performance across groups. In conclusion, differences in WM microstructure in ADHD presentations strengthen the theory that ADHD-PI and ADHD-C are two distinct disorders. Regions with WM irregularity seen in both ADHD presentations might serve as predictors of executive and behavioral functioning across groups. Hum Brain Mapp 37:3323-3336, 2016. © 2016 Wiley Periodicals, Inc.

An exploratory study of brain function and structure in mucopolysaccharidosis type I: long term observations following hematopoietic cell transplantation (HCT)

AIM

Although hematopoietic cell transplantation (HCT) arrests the cognitive decline in mucopolysaccharidosis type IH (Hurler syndrome, MPS IH), these children continue to have neuropsychological deficits as they age. Both compromised attention and effects on white matter have been observed in cancer patients who have had chemotherapy. Therefore, we explored the effects of disease and treatment on brain function in children with MPS I who have had HCT with those with attenuated MPS I treated with enzyme replacement therapy (ERT).

SUBJECTS

7 MPS IH participants at least 5 years post-HCT were compared with 7 attenuated participants who were treated with ERT.

MEASURES

IQ, attention, spatial ability, and memory were assessed. Medical history and an unsedated MRI scan using diffusion tensor imaging (DTI) were acquired.

RESULTS

Despite clinically equivalent IQ and memory, children with MPS IH had poorer attention span than those with attenuated MPS I as well as decreased fractional anisotropy (FA) of the corpus callosum. A relationship between attention scores and FA was found in the MPS IH group but not the attenuated group. FA was also related to the frequency of medical events.

INTERPRETATION

In children with MPS IH, both the treatment and the disease affect attention functions associated with poor white matter integrity.

Cognitive, medical, and neuroimaging characteristics of attenuated mucopolysaccharidosis type II

The phenotype of attenuated mucopolysaccharidosis type II (MPS II), also called Hunter syndrome, has not been previously studied in systematic manner. In contrast to the "severe" phenotype, the "attenuated" phenotype does not present with behavioral or cognitive impairment; however, the presence of mild behavior and cognitive impairment that might impact long-term functional outcomes is unknown. Previously, significant MRI abnormalities have been found in MPS II. Recent evidence suggests white matter abnormalities in many MPS disorders.

METHODS

As the initial cross-sectional analysis of a longitudinal study, we studied the association of brain volumes and somatic disease burden with neuropsychological outcomes, including measures of intelligence, memory, and attention in 20 patients with attenuated MPS II with a mean age of 15.8. MRI volumes were compared to 55 normal controls.

RESULTS

While IQ and memory were average, measures of attention were one standard deviation below the average range. Corpus callosum volumes were significantly different from age-matched controls, differing by 22%. Normal age-related volume increases in white matter were not seen in MPS II patients as they were in controls. Somatic disease burden and white matter and corpus callosum volumes were significantly associated with attention deficits. Neither age at evaluation nor age at starting treatment predicted attention outcomes.

CONCLUSIONS

Despite average intelligence, attention is compromised in attenuated MPS II. Results confirm an important role of corpus callosum and cortical white matter abnormality in MPS II as well as the somatic disease burden in contributing to attention difficulties. Awareness by the patient and caregivers with appropriate management and symptomatic support will benefit the attenuated MPS II patient.

Variations in 24-Hour BP Profiles in Cohorts of Patients with Kidney Disease around the World: The I-DARE Study

BACKGROUND AND OBJECTIVES

Ambulatory BP is increasingly recognized as a better measure of the risk for adverse outcomes related to hypertension, an important comorbidity in patients with CKD. Varying definitions of white-coat and masked hypertension have made it difficult to evaluate differences in prevalence of these BP patterns across CKD cohorts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The International Database of Ambulatory BP in Renal Patients collaborative group established a large database of demographic, clinical, and ambulatory BP data from patients with CKD from cohorts in Italy, Spain, the Chronic Renal Insufficiency Cohort (CRIC) and the African American Study of Kidney Disease and Hypertension Cohort Study (AASK) in the United States, and the CKD Japan Cohort (CKD-JAC). Participants (n=7518) with CKD were included in the present analyses. Cutoffs for defining controlled BP were 140/90 mm Hg for clinic and 130/80 mm Hg for 24-hour ambulatory BP.

RESULTS

Among those with controlled clinic BP, compared with CKD-JAC, AASK participants were more likely to have masked hypertension (prevalence ratio [PR], 1.21; 95% confidence interval [95% CI], 1.04 to 1.41) whereas CRIC (PR, 0.82; 0.72 to 0.94), Italian (PR, 0.73; 0.56 to 0.95), and Spanish participants (PR, 0.75; 0.64 to 0.88) were less likely. Among those with elevated clinic BP, AASK participants were more likely to have sustained hypertension (PR, 1.22; 95% CI, 1.13 to 1.32) whereas Italian (PR, 0.78; 0.70 to 0.87) and Spanish participants (PR, 0.89; 0.82 to 0.96) were less likely, although CRIC participants had similar prevalence as CKD-JAC. Prevalence of masked and sustained hypertension was elevated in males, patients with diabetes, participants on four or more antihypertensives, and those with moderate-to-severe proteinuria.

CONCLUSIONS

In a large, multinational database, the prevalence of masked and sustained hypertension varied across cohorts independent of important comorbidities.

Mild elevations of urine albumin excretion are associated with atherogenic lipoprotein abnormalities in the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE

Elevated urine albumin excretion is an established risk factor for cardiovascular disease. Increased cardiovascular risk may be partly mediated by abnormalities in lipoprotein metabolism. We examined cross-sectional associations of urine albumin-creatinine ratio (ACR) with standard lipid measurements and with lipoprotein particle concentrations measured by nuclear magnetic resonance (NMR) in the Multi-Ethnic Study of Atherosclerosis.

METHODS AND RESULTS

Among 5633 participants who were not using lipid-lowering medications, greater ACR was associated with greater triglyceride concentration and lesser high density lipoprotein cholesterol concentration (women only), but not with low density lipoprotein (LDL) cholesterol calculated using conventional methods. In contrast, unadjusted mean small LDL particle concentrations measured by NMR were 770, 827 and 935 nmol/L for women (p<0.001) and 996, 1030 and 1040 nmol/L for men (p=0.037) among participants with normal, high normal and elevated ACR. Adjusting for age, race/ethnicity, diabetes, impaired fasting glucose, hypertension, smoking, medications, body mass index and serum creatinine, each two-fold greater ACR was associated with an increase in small LDL particle concentration of 27 nmol/L for women (p<0.001) and 14 nmol/L for men (p=0.008). Greater ACR was also associated with greater intermediate density lipoprotein particle concentration and smaller mean LDL particle size.

CONCLUSIONS

Mild elevations of urine ACR are associated with atherogenic lipoprotein abnormalities that are not directly observed with a standard lipid panel.

Neurocognitive and neuropsychiatric phenotypes associated with the mutation L238Q of the α-L-iduronidase gene in Hurler-Scheie syndrome

The lysosomal enzyme α-L-iduronidase hydrolyzes terminal iduronic acid from heparan sulfate and dermatan sulfate, and is an essential step in GAG degradation. Mutations of its gene, IDUA, yield a spectrum of mucopolysaccharidosis (MPS) type I clinical disorders. The IDUA mutation, c.712T>A (p.L238Q) was previously noted as a mild mutation. In a longitudinal study of MPS brain structure and function (Lysosomal Disease Network), we found this mutation in 6 of 14 Hurler-Scheie syndrome patients in the age range of 15 to 25 years. We hypothesized that L238Q, when paired with a nonsense mutation, is significantly more severe than other missense-nonsense combinations.

METHODS

Of 6 patients with a L238Q mutation, the L238Q allele was paired with a nonsense mutation in 4 patients, paired with a deletion in 1, and with a splice site mutation in another. This group was compared to 6 Hurler-Scheie patients closely matched in age and mutation type. IQ and other neuropsychological tests were administered as part of the protocol. Medical history was compiled into a Physical Symptom Score (PSS). Assessment of IQ, attention, memory, spatial ability, adaptive function and psychological status were measured.

RESULTS

No group differences were found in mean age at evaluation (17.8 and 19.0 years), duration of ERT, or PSS. By history, all were reported to be average in IQ (4/6 with documentation) in early childhood. All (100%) of the L238Q group had a psychiatric history and sleep problems compared to none (0%) of the comparison group. Significant differences were found in depression and withdrawal on parent report measures. IQ was lower in the L238Q group (mean IQ 74) than the comparison group (mean IQ 95; p<0.016). Attention, memory, and visual-spatial ability scores were also significantly lower. Three occurrences of shunted hydrocephalus, and 4 of cervical cord compression were found in the L238Q group; the comparison group had one occurrence of unshunted hydrocephalus and two of cord compression.

DISCUSSION

The missense mutation L238Q, when paired with a nonsense mutation, is associated with significant, late-onset brain disease: psychiatric disorder, cognitive deficit, and general decline starting at a later age than in Hurler syndrome with a mutation-related rate of GAG accumulation and its pathologic sequelae. This particular genotype-phenotype may provide insight into the genesis of psychiatric illnesses more broadly. Consideration of methods for early, brain-targeted treatment in these patients might be considered.

A longitudinal study of emotional adjustment, quality of life and adaptive function in attenuated MPS II

OBJECTIVES

The behavioral, adaptive and quality of life characteristics of attenuated mucopolysaccharidosis type II (MPS II) have not been well studied. Understanding changes over time in the attenuated phenotype may assist in helping achieve better outcomes in long-term function. This longitudinal study investigates these outcomes in relation to age, somatic disease burden, and IQ. Specifically, somatic disease burden is a major challenge for these patients, even with treatment with enzyme replacement therapy.

METHODS

15 patients, 10 between ages 6 and < 12 and 5 between ages ≥ 12 and 18, were selected who had at least 2 yearly visits. The occurrence of physical signs, the Physical Symptom Score, and IQ in these two groups was studied as well as the longitudinal association of age with standardized measures of quality of life, adaptive function, and behavioral symptoms as rated by parents and the child's self-report. Slopes by age across and within patients were calculated for these measures.

RESULTS

All but one child had hearing loss, most had joint contractures and short stature. Somatic disease burden increased with age. IQ, although normal for most, also improved with age in those under 12 years of age. Physical quality of life decreased while psychosocial quality of life increased with age. Although other adaptive skills were in the broad average range, daily living skills were low at baseline relative to normative data and decreased over time. Behavior ratings indicated improvement in attention and hyperactivity over time. No patient had severe psychopathology, but older children reported an increasing sense of inadequacy and low self-esteem on self-report, presumably due to increasing awareness of differences from peers over time.

CONCLUSIONS

Attenuated MPS II patients have increasing somatic disease burden and poor physical quality of life as they develop as well as decreasing self-esteem and sense of adequacy. Psychosocial quality of life, adaptive skills, and attention improve. Recognition of and intervention around these issues will be beneficial to MPS II attenuated patients who have the resources to use such assistance to improve their long-term outcomes.

Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol

Background

Perinatal stroke occurs in more than 1 in 2,500 live births and resultant congenital hemiparesis necessitates investigation into interventions which may improve long-term function and decreased burden of care beyond current therapies (http://www.cdc.gov/ncbddd/cp/data.html). Constraint-Induced Movement Therapy (CIMT) is recognized as an effective hemiparesis rehabilitation intervention . Transcranial direct current stimulation as an adjunct treatment to CIMT may potentiate neuroplastic responses and improve motor function. The methodology of a clinical trial in children designed as a placebo-controlled, serial –session, non-invasive brain stimulation trial incorporating CIMT is described here. The primary hypotheses are 1) that no serious adverse events will occur in children receiving non-invasive brain stimulation and 2) that children in the stimulation intervention group will show significant improvements in hand motor function compared to children in the placebo stimulation control group.

Methods/design

A randomized, controlled, double-blinded clinical trial. Twenty children and/or young adults (ages 8–21) with congenital hemiparesis, will be enrolled. The intervention group will receive ten 2-hour sessions of transcranial direct current stimulation combined with constraint-induced movement therapy and the control group will receive sham stimulation with CIMT. The primary outcome measure is safety assessment of transcranial direct current stimulation by physician evaluation, vital sign monitoring and symptom reports. Additionally, hand function will be evaluated using the Assisting Hand Assessment, grip strength and assessment of goals using the Canadian Occupational Performance Measure. Neuroimaging will confirm diagnoses, corticospinal tract integrity and cortical activation. Motor cortical excitability will also be examined using transcranial magnetic stimulation techniques.

Discussion

Combining non-invasive brain stimulation and CIMT interventions has the potential to improve motor function in children with congenital hemiparesis beyond each intervention independently. Such a combined intervention has the potential to benefit an individual throughout their lifetime.

Trial registration

Clinicaltrials.gov, NCT02250092Registered 18 September 2014

Pilot study of the safety and effect of adalimumab on pain, physical function, and musculoskeletal disease in mucopolysaccharidosis types I and II

Mucopolysaccharidosis I and II are lysosomal storage disorders that, despite treatment with hematopoietic cell transplantation (HCT) and/or enzyme replacement therapy (ERT), continue to cause significant skeletal abnormalities leading to pain, stiffness, physical dysfunction, and short stature. Tumor necrosis factor – alpha (TNF-α) is elevated in individuals with MPS I and II and associated with pain and physical dysfunction. Therefore, we evaluated the safety and effects of the TNF-α inhibitor adalimumab in patients with MPS I and II in a 32-week, randomized, double blind, placebo-controlled, crossover study of adalimumab at a dose of 20 mg (weight 15–<30 kg) or 40 mg (weight ≥ 30 kg) administered subcutaneously every other week or saline placebo for 16 weeks. Participants were evaluated at baseline, week 16, and week 32 with the Children's Health Questionnaire – Parent Form 50 (CHQ-PF50), the Pediatric Pain Questionnaire (PPQ), range-of-motion (ROM) measurements, anthropometry, six-minute walk test (6MWT), hand dynamometer, and laboratory evaluations for safety. The primary outcome was safety and primary efficacy outcome was bodily pain (BP) measured by the CHQ-PF50. Two subjects, one with MPS I and one with MPS II, completed the study. Adalimumab was well tolerated and there were no serious adverse events. Standardized BP scores for age and gender were higher (i.e. less pain) at the end of the treatment versus placebo phase for both subjects. Subject #1 became unblinded during treatment due to skin erythema. Behavior measured by both CHQ-PF50 and parental report improved during treatment compared to placebo in both subjects. ROM improved by > 5° in seven of eight joints in Subject #1 and five of eight joints in Subject #2 (range 7.0° to 52.8°). There was no change in the PPQ, 6MWT, or hand dynamometer. Data from this small pilot study suggest that treatment with adalimumab is safe, tolerable, and may improve ROM, physical function, and possibly pain, in children with MPS I or II. However, additional clinical trials are needed before this therapy should be recommended as part of clinical care.

Mucopolysaccharidosis Type IIIA presents as a variant of Klüver-Bucy syndrome

Mucopolysaccharidosis Type IIIA (MPS IIIA) is a neurodegenerative disease with behavioral symptoms unique among the mucopolysaccharidoses. Children with MPS IIIA reportedly mouth things, explore novel environments almost continuously, disregard danger, and empathize/socialize and comply less with parents. These characteristics resemble Klüver-Bucy syndrome (K-Bs). To test the K-Bs hypothesis, 30 children with MPS IIIA were compared to 8 "posttransplant" mucopolysaccharidosis Type IH patients in an experimental "risk room." The room contained attractive and mildly frightening objects, exposure to a 92-dB startle noise triggered by contact with an attractive toy, mother's return after a brief absence, and compliance with her cleanup directive. Children with MPS IIIA: (a) left mother sooner, (b) wandered more, (c) were more likely to approach frightening objects, (d) were less likely to respond to loud noise with whole body startle, (e) were less likely to avoid the toy associated with the startle noise, (f) interacted less with mother upon her return, and (g) complied less with her cleanup command. K-Bs is associated with loss of amygdala function. Brain magnetic resonance imaging (MRI) of a subset of the children with MPS IIIA showed volume loss that was greater in the amygdala than in the hippocampus; only amygdala loss correlated with reduced fearfulness. MPS IIIA may be the first identified pediatric disease presenting systematically as a K-Bs variant. If validated by further studies, the K-Bs hypothesis of MPS IIIA would provide important clinical and theoretical information for the guidance of families as well as markers for natural disease progression and treatment effects.

Biomarkers of bone remodeling in children with mucopolysaccharidosis types I, II, and VI

PURPOSE

Skeletal disease causes significant morbidity in mucopolysaccharidoses (MPS), and bone remodeling processes in MPS have not been well characterized. The objective of this study was to determine if biomarkers of bone turnover are abnormal in children with specific MPS disorders (i.e. MSP-I, MPS-II, and MPS-VI) compared to healthy children.

METHODS

A cross-sectional study was performed of serum biomarkers of bone formation (bone-specific alkaline phosphatase [BSAP], osteocalcin) and urine biomarkers of bone resorption (pyridinoline, deoxypyridinoline) in MPS and healthy controls. Measures of physical function and pain were obtained using the Children's Health Questionnaire (CHQ).

RESULTS

The cohort consisted of 39 children with MPS (MPS-I=26; MPS-II=11; MPS-VI=4) and 51 healthy children. Adjusting for sex and Tanner stage group, MPS individuals had statistically significant increases for osteocalcin (p< 0.001), with trends toward higher BSAP (p=0.054) and urinary pyridinoline (p=0.084). These biomarkers were not significantly associated with CHQ bodily pain and physical-function scores.

CONCLUSION

Osteocalcin was increased in children with MPS disorders, with trends for increases in BSAP and urinary pyridinoline, suggesting that bone remodeling is altered in children with MPS. Future studies to assess the ability of these biomarkers to quantify and monitor MPS skeletal disease in response to therapy are needed.

Combining parametric, semi-parametric, and non-parametric survival models with stacked survival models

For estimating conditional survival functions, non-parametric estimators can be preferred to parametric and semi-parametric estimators due to relaxed assumptions that enable robust estimation. Yet, even when misspecified, parametric and semi-parametric estimators can possess better operating characteristics in small sample sizes due to smaller variance than non-parametric estimators. Fundamentally, this is a bias-variance trade-off situation in that the sample size is not large enough to take advantage of the low bias of non-parametric estimation. Stacked survival models estimate an optimally weighted combination of models that can span parametric, semi-parametric, and non-parametric models by minimizing prediction error. An extensive simulation study demonstrates that stacked survival models consistently perform well across a wide range of scenarios by adaptively balancing the strengths and weaknesses of individual candidate survival models. In addition, stacked survival models perform as well as or better than the model selected through cross-validation. Finally, stacked survival models are applied to a well-known German breast cancer study.

The Spectrum of Bladder Health: The Relationship Between Lower Urinary Tract Symptoms and Interference with Activities

Background: Little research to date has focused on lower urinary tract symptom (LUTS) prevention and bladder health promotion in women. To address this gap, the Prevention of LUTS Research Consortium developed the following working bladder health definition: "A complete state of physical, mental, and social well-being related to bladder function [that] permits daily activities [and] allows optimal well-being." To begin to inform and quantify this definition, we used data from the Boston Area Community Health Survey, drawing upon its rare collection of information on LUTS and LUTS-specific interference with activities. Methods: At baseline, participants reported their frequency of 15 LUTS and interference with 7 activities. Prevalence ratios (PRs) were calculated by generalized linear models with robust variance estimation, adjusting for LUTS risk factors and individual LUTS. Results: Of the 3169 eligible participants, 17.5% reported no LUTS or interference, whereas the remaining 82.5% reported some frequency of LUTS/interference: 15.1% rarely; 21.7% a few times; 22.6% fairly often/usually; and 22.9% almost always. LUTS independently associated with interference were urgency incontinence, any incontinence, urgency, nocturia, perceived frequency, and urinating again after <2 hours (PRs = 1.2-1.5, all p < 0.05). Conclusions: Our findings suggest that bladder health exists on a continuum, with approximately one in five women considered to have optimal bladder health (no LUTS/interference), the majority to have intermediate health (LUTS/interference rarely to usually), and a further one in five to have worse or poor health (LUTS/interference almost always). These findings underscore the need for LUTS prevention and bladder health promotion.

Association of somatic burden of disease with age and neuropsychological measures in attenuated mucopolysaccharidosis types I, II and VI

INTRODUCTION

The mucopolysaccharidoses (MPSs) are a group of rare genetic lysosomal disorders with progressive multisystem involvement. An MPS-specific physical symptom scale was developed and introduced a Physical Symptom Score (PSS) to quantify the somatic disease burden across MPS I, II and VI.

HYPOTHESIS

Somatic burden of disease in patients with attenuated MPS I, II and VI as measured by the PSS will be positively associated with age and negatively associated with neuropsychological functions [i.e. full scale intelligence quotient (FSIQ) and attention].

MATERIALS AND METHODS

Forty-eight patients with attenuated MPS I (n = 24), II (n = 14), and VI (n = 10) aged 6 to 32 years on enzyme replacement therapy who were enrolled in "Longitudinal Studies of Brain Structure and Functions in MPS Disorders" across seven centers. Somatic disease burden was measured by the PSS. Neuropsychological functions were measured by the Wechsler Abbreviated Scale of Intelligence (WASI) and Test of Variables of Attention (TOVA).

RESULTS

PSS was positively associated with age in attenuated MPS I (P < 0.001), MPS II (P < 0.01) and MPS VI (P < 0.05). There was a negative association of PSS with FSIQ in attenuated MPS I (P < 0.001) and in MPS VI (P < 0.001) but not with MPS II. Although attention scores were below average in all groups, a significant negative association between PSS and one measures of sustained attention (TOVA d prime) was found only in MPS VI.

CONCLUSIONS

Physical Symptom Score increased with age in attenuated MPS I, II and VI, reflecting progressive somatic burden of disease despite treatment with enzyme replacement therapy. Furthermore, the association of increased somatic disease burden with decreased neurocognitive ability suggests that both measures reflect disease severity and are not independent.