Catherine Groden

Both IL-12p70 and IL-23 Are Synthesized During Active Crohn's Disease and Are Down-regulated by Treatment with Anti-IL-12 p40 Monoclonal Antibody

Background: Interleukin (IL)‐12p70 and IL‐23 are key T helper‐1 (TH1) cytokines that drive the inflammation seen in numerous models of intestinal inflammation. These molecules contain an identical p40 chain that is bound to a p35 chain in IL‐12 and a p19 chain in IL‐23, making both potentially susceptible to modulation by an anti‐IL‐12p40 monoclonal antibody (mAb). Methods: In the present study, we sought to determine whether active inflammation in Crohns disease (CD) is associated with the increased synthesis of both of these cytokines and whether patients treated with an anti‐IL‐12p40 mAb down‐regulate IL‐23 as well as IL‐12p70 as previous reported. Results: To this end we initially determined that IL‐12p70 secretion by control and CD antigen‐presenting cells (macrophages) in lamina propria mononuclear populations is optimized by stimulation with CD40L and interferon‐&ggr;. In subsequent studies using these stimulation conditions we found that patients with CD manifested both increased IL‐12p70 and IL‐23 secretion before anti‐IL‐12p40 mAb treatment and normal levels of secretion of these cytokines following cessation of treatment. Antigen‐presenting cells in lamina propria mononuclear cells from ulcerative colitis patients, in contrast, produced only baseline levels of IL‐23. Finally, we found that IL‐23‐induced T cell production of IL‐17 and IL‐6 are also greatly reduced after antibody treatment. The latter data are parallel to those from previous studies showing that anti‐IL‐12p40 down‐regulates IFN‐&ggr; and tumor necrosis factor‐&agr; secretion. Conclusions: We conclude that CD but not ulcerative colitis is associated with high levels of both IL‐12p70 and IL‐23 secretion as well as the secretion of downstream effector cytokines, and that this cytokine production is down‐regulated following administration of IL‐12p40 mAb.

The National Institutes of Health Undiagnosed Diseases Program: insights into rare diseases

Purpose:This report describes the National Institutes of Health Undiagnosed Diseases Program, details the Program’s application of genomic technology to establish diagnoses, and details the Program’s success rate during its first 2 years.Methods:Each accepted study participant was extensively phenotyped. A subset of participants and selected family members (29 patients and 78 unaffected family members) was subjected to an integrated set of genomic analyses including high-density single-nucleotide polymorphism arrays and whole exome or genome analysis.Results:Of 1,191 medical records reviewed, 326 patients were accepted and 160 were admitted directly to the National Institutes of Health Clinical Center on the Undiagnosed Diseases Program service. Of those, 47% were children, 55% were females, and 53% had neurologic disorders. Diagnoses were reached on 39 participants (24%) on clinical, biochemical, pathologic, or molecular grounds; 21 diagnoses involved rare or ultra-rare diseases. Three disorders were diagnosed based on single-nucleotide polymorphism array analysis and three others using whole exome sequencing and filtering of variants. Two new disorders were discovered. Analysis of the single-nucleotide polymorphism array study cohort revealed that large stretches of homozygosity were more common in affected participants relative to controls.Conclusion:The National Institutes of Health Undiagnosed Diseases Program addresses an unmet need, i.e., the diagnosis of patients with complex, multisystem disorders. It may serve as a model for the clinical application of emerging genomic technologies and is providing insights into the characteristics of diseases that remain undiagnosed after extensive clinical workup.Genet Med 2012:14(1):51–59

Suppression of inflammation in ulcerative colitis by interferon-β-1a is accompanied by inhibition of IL-13 production

Objective Ulcerative colitis is associated with increased interleukin 13 (IL-13) production by natural killer T cells. Taking advantage of the inhibitory actions of interferon β on IL-13 expression, this proof-of-concept study aimed to show that decreasing IL-13 production is associated with clinical improvement of ulcerative colitis symptoms. Design Open-label interventional drug trial. Setting Outpatient clinical research hospital. Patients Adult patients with active ulcerative colitis (Short Clinical Colitis Activity Index (SCCAI)≥5). Interventions Treatment with 30 μg IM interferon-β-1a (Avonex) weekly for 12 weeks with 6 month follow-up. Main outcome measures Clinical response was defined as ≥3 point drop in the SCCAI for at least two consecutive monitoring visits, and cytokine production was measured in cultured peripheral blood and lamina propria mononuclear cells (LPMC) before and after treatment. Results 11 of 16 patients were clinical responders, and 4 were in remission (SCCAI ≤ 2) at the end of treatment. Rectal bleeding subscores improved dramatically by week 4 (38% with frank bleeding vs 87% pretreatment). Increased IL-13 production by LPMC T cells fell significantly in clinical responders (690±99 vs 297±58 pg/ml p=0.015) but was unchanged in non-responders (542±83 vs 510±39 pg/ml). In addition, non-responders had significantly higher production of IL-17 and IL-6 pre-treatment compared to responders. Conclusions Interferon-β-1a induces clinical response and remission in a large subset of patients with ulcerative colitis that is associated with significant inhibition of IL-13 production. In addition, increased IL-17 and IL-6 production is associated with no response to interferon-β. These data provide a proof-of-concept that IL-13 is an effector cytokine in ulcerative colitis and should be a target for novel therapies.

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow.

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with (18)F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H(2)(15)O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the pattern of dopamine loss in patients with both Parkinson and Gaucher disease was similar to sporadic Parkinson disease, indicating comparable damage in midbrain neurons. However, H(2)(15)O positron emission tomography studies indicated that these subjects have decreased resting activity in a pattern characteristic of diffuse Lewy body disease. These findings provide insight into the pathophysiology of GBA-associated parkinsonism.

The implications of familial incidental findings from exome sequencing: the NIH Undiagnosed Diseases Program experience.

Purpose:Using exome sequence data from 159 families participating in the National Institutes of Health Undiagnosed Diseases Program, we evaluated the number and inheritance mode of reportable incidental sequence variants.Methods:Following the American College of Medical Genetics and Genomics recommendations for reporting of incidental findings from next-generation sequencing, we extracted variants in 56 genes from the exome sequence data of 543 subjects and determined the reportable incidental findings for each participant. We also defined variant status as inherited or de novo for those with available parental sequence data.Results:We identified 14 independent reportable variants in 159 (8.8%) families. For nine families with parental sequence data in our cohort, a parent transmitted the variant to one or more children (nine minor children and four adult children). The remaining five variants occurred in adults for whom parental sequences were unavailable.Conclusion:Our results are consistent with the expectation that a small percentage of exomes will result in identification of an incidental finding under the American College of Medical Genetics and Genomics recommendations. Additionally, our analysis of family sequence data highlights that genome and exome sequencing of families has unavoidable implications for immediate family members and therefore requires appropriate counseling for the family.Genet Med 16 10, 741–750.

Computational evaluation of exome sequence data using human and model organism phenotypes improves diagnostic efficiency.

Purpose:Medical diagnosis and molecular or biochemical confirmation typically rely on the knowledge of the clinician. Although this is very difficult in extremely rare diseases, we hypothesized that the recording of patient phenotypes in Human Phenotype Ontology (HPO) terms and computationally ranking putative disease-associated sequence variants improves diagnosis, particularly for patients with atypical clinical profiles.Methods:Using simulated exomes and the National Institutes of Health Undiagnosed Diseases Program (UDP) patient cohort and associated exome sequence, we tested our hypothesis using Exomiser. Exomiser ranks candidate variants based on patient phenotype similarity to (i) known disease–gene phenotypes, (ii) model organism phenotypes of candidate orthologs, and (iii) phenotypes of protein–protein association neighbors.Results:Benchmarking showed Exomiser ranked the causal variant as the top hit in 97% of known disease–gene associations and ranked the correct seeded variant in up to 87% when detectable disease–gene associations were unavailable. Using UDP data, Exomiser ranked the causative variant(s) within the top 10 variants for 11 previously diagnosed variants and achieved a diagnosis for 4 of 23 cases undiagnosed by clinical evaluation.Conclusion:Structured phenotyping of patients and computational analysis are effective adjuncts for diagnosing patients with genetic disorders.Genet Med 18 6, 608–617.

Successful granulocyte-colony stimulating factor treatment of Crohn's disease is associated with the appearance of circulating interleukin-10-producing T cells and increased lamina propria plasmacytoid dendritic cells

Granulocyte‐colony stimulating factor (G‐CSF) has proved to be a successful therapy for some patients with Crohns disease. Given the known ability of G‐CSF to exert anti‐T helper 1 effects and to induce interleukin (IL)‐10‐secreting regulatory T cells, we studied whether clinical benefit from G‐CSF therapy in active Crohns disease was associated with decreased inflammatory cytokine production and/or increased regulatory responses. Crohns patients were treated with G‐CSF (5 µg/kg/day subcutaneously) for 4 weeks and changes in cell phenotype, cytokine production and dendritic cell subsets were measured in the peripheral blood and colonic mucosal biopsies using flow cytometry, enzyme‐linked immunosorbent assay and immunocytochemistry. Crohns patients who achieved a clinical response or remission based on the decrease in the Crohns disease activity index differed from non‐responding patients in several important ways: at the end of treatment, responding patients had significantly more CD4+ memory T cells producing IL‐10 in the peripheral blood; they also had a greatly enhanced CD123+ plasmacytoid dendritic cell infiltration of the lamina propria. Interferon‐γ production capacity was not changed significantly except in non‐responders, where it increased. These data show that clinical benefit from G‐CSF treatment in Crohns disease is accompanied by significant induction of IL‐10 secreting T cells as well as increases in plasmacytoid dendritic cells in the lamina propria of the inflamed gut mucosa.

The clinical management of type 2 Gaucher disease

Gaucher disease, the inherited deficiency of the enzyme glucocerebrosidase, is the most common of the lysosomal storage disorders. Type 2 Gaucher disease, the most severe and progressive form, manifests either prenatally or in the first months of life, followed by death within the first years of life. The rarity of the many lysosomal storage disorders makes their diagnosis a challenge, especially in the newborn period when the focus is often on more prevalent illnesses. Thus, a heightened awareness of the presentation of these rare diseases is necessary to ensure their timely consideration. This review, designed to serve as a guide to physicians treating newborns and infants with Gaucher disease, discusses the presenting manifestations of Type 2 Gaucher disease, the diagnostic work-up, associated genotypes and suggestions for management. We also address the ethical concerns that may arise with this progressive and lethal disorder, since currently available treatments may prolong life, but do not impact the neurological manifestations of the disease.

Idiopathic Basal Ganglia Calcifications: An Atypical Presentation of PKAN

BACKGROUND We report a patient with pantothenate kinase-associated neurodegeneration presenting as idiopathic basal ganglia calcifications, previously known as Fahrs disease. METHODS A teenage girl presented with slowly progressive dystonia. Her brain magnetic resonance imaging scan revealed T1 and T2 hypointensities in both globus pallidi, and no eye-of-the-tiger sign. Computed tomography showed dense globus pallidi calcifications. Metabolic evaluation was negative. The patient was diagnosed with idiopathic basal ganglia calcifications, a poorly understood syndrome of unknown cause. Whole exome sequencing was performed. RESULTS The patient was found to have two mutations in the pantothenate kinase 2 (PANK2) gene that have been previously associated with pantothenate kinase-associated neurodegeneration: a paternally inherited p.G521R and maternally inherited p.T528M. No deleterious changes were identified in genes associated with idiopathic basal ganglia calcifications or dystonia. CONCLUSIONS Pantothenate kinase-associated neurodegeneration should be considered in patients with idiopathic basal ganglia calcifications, especially when findings are confined to the globus pallidus.

Multiple endoscopic biopsies in research subjects : safety results from a National Institutes of Health series

BACKGROUND Routine endoscopic mucosal biopsies are generally considered safe. However, the outcomes of performing large numbers of biopsies in subjects enrolled in research protocols have not been reported. OBJECTIVE Our purpose was to assess the safety of taking numerous mucosal biopsy specimens during endoscopic procedures (eg, >20/endoscopic procedure) in research subjects. DESIGN Single-center retrospective chart review. SETTING Research hospital: National Institutes of Health (NIH) Clinical Center. PATIENTS Volunteers who underwent research protocol endoscopies with large numbers of biopsies during 2001 to 2008 at the NIH. MAIN OUTCOME MEASUREMENTS Charts were reviewed for the occurrence of procedure-related major/minor complications. RESULTS A total of 253 research endoscopies were performed on 133 patients: 169 colonoscopies, 64 sigmoidoscopies, and 20 upper endoscopies. A total of 9,661 biopsy specimens were obtained for research and histopathologic examination (mean 38.2 +/- 15.6 per procedure). No major complications were identified. Minor complications occurred with 13 (5.1%) lower endoscopic procedures and included self-limited bleeding (4), pain (5), or both (4). There was no statistically significant association between the number of biopsies, type of procedure, location of research biopsies, operator, polypectomy, or the use of nonsteroidal anti-inflammatory drugs and the risk of complications. LIMITATIONS Retrospective design, modest sample size. CONCLUSIONS This is the first report on the safety of performing large numbers of endoscopic biopsies in research subjects. This practice is well tolerated and appears to have no more than minimal risk without appreciably increasing the risk of otherwise routine endoscopy.