Jeremiah Levine

Variation at NOD2/CARD15 in familial and sporadic cases of Crohn’s disease in the Ashkenazi Jewish population

OBJECTIVE:Recent reports indicate that allelic variants in NOD2/CARD15 are associated with Crohns disease (CD) susceptibility, and that homozygosity or compound heterozygosity at this locus for any of three recently defined sequence variants confers a greatly increased risk of CD. These sequence changes include two missense mutations, R702W and G908R, and a frameshift insertion, 1007insC. The aim of this study was to determine the frequency of these NOD2/CARD15 variants in familial and sporadic CD patients in the Ashkenazi population and to determine their effects on disease susceptibility and age of disease onset (AOO).METHODS:Allele and genotype frequencies of these three variants were determined in 481 CD patients of Jewish descent and 110 Jewish controls; 169 patients had a family history of CD, and 312 were “sporadic” cases. Variants were detected by polymerase chain reaction using allele-specific primers labeled with fluorescent dye.RESULTS:Familial cases had a significantly higher frequency of the G908R variant than sporadic cases (0.127 vs 0.059, p = 0.0003) and correspondingly, a significantly higher proportion of homozygotes and compound heterozygotes (11.8% vs 4.5%, p = 0.0027). Homozygotes and compound heterozygotes had an OR for CD of 14.6 for familial cases and 5.1 for sporadic cases. There was no increased risk of CD for simple heterozygotes. The AOO was significantly lower for CD patients who were homozygotes and compound heterozygotes for NOD2/CARD15 (17.5 vs 22.4 yr, p = 0.04), but only for familial cases.CONCLUSIONS:NOD2/CARD15 contributes more to CD susceptibility in familial cases than in sporadic cases, and to an earlier AOO. There is no increased risk of CD for individuals carrying only a single copy of these NOD2/CARD15 variants, whereas individuals carrying two copies have a 5–15-fold increased risk. The penetrance of the NOD2/CARD15 mutations was estimated at less than 1%.

Effects of infliximab on apoptosis and reverse signaling of monocytes from healthy individuals and patients with Crohn's disease.

Objectives: Infliximab, an anti-tumor necrosis factor (TNF) monoclonal antibody, might exert some of its long-term therapeutic effects in Crohns disease (CD) by interacting directly with cells of the immune system such as monocytes and T lymphocytes via membrane TNF and by inducing apoptosis. Accordingly, the effects of inflix-imab on monocyte apoptosis and down-regulation of proinflammatory cytokines (reverse signaling) were assessed. Methods: To assess apoptosis, monocytes from healthy individuals (controls) and CD patients were incubated in the presence or absence of infliximab or the apoptotic agent gliotoxin for 24 hours. Annexin V staining and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-FITC nick end labeling assay were used to measure early and late apoptosis. To measure the effects of infliximab on reverse signaling, monocytes from healthy individuals pretreated in vitro with infliximab were stimulated with lipopolysaccharide or staphylococcal enterotoxin A, and the induction of the proinflammatory cytokines, TNF-α, interleukin (IL)-1β, IL-6, and IL-8 was measured by reverse transcription polymerase chain reaction. The effect of in vivo infliximab treatment of monocytes was similarly determined by comparing the responses of monocytes from CD patients before and immediately after infliximab infusion. Results: Infliximab did not induce apoptosis of monocytes from either healthy individuals or CD patients but rather stabilized them. However, monocytes from healthy individuals treated with infliximab in vitro, or from CD patients infused with infliximab, produced significantly less TNF and other proinflammatory cytokines when stimulated with the bacterial products lipopolysaccharide and staphylococcal enterotoxin A. Conclusions: Apoptosis of monocytes is not responsible for the therapeutic effects of infliximab. However, some of the therapeutic effects of infliximab may be caused by its ability to down-regulate proinflammatory cytokines production by monocytes exposed to bacterial antigens.

Pancolonic disease in cystic fibrosis and high-dose pancreatic enzyme therapy☆☆☆★

We describe a child with cystic fibrosis who was treated with high-dose pancreatic enzyme replacement therapy and who had a prominent ascending colon stricture with submucosal fibrosis. Unlike prior reported cases, this patients disease was more extensive, involving the entire colon, and was associated with chylous ascites.

Severe obesity and diabetes insipidus in a patient with PCSK1 deficiency.

Non-synonymous mutations affecting both alleles of PCSK1 (proprotein convertase 1/3) are associated with obesity and impaired prohormone processing. We report a proband who was compound heterozygous for a maternally inherited frameshift mutation and a paternally inherited 474kb deletion that encompasses PCSK1, representing a novel genetic mechanism underlying this phenotype. Although pro-vasopressin is not a known physiological substrate of PCSK1, the development of central diabetes insipidus in this proband suggests that PCSK1 deficiency can be associated with impaired osmoregulation.

The IBD1 locus for susceptibility to Crohn’s disease has a greater impact in Ashkenazi Jews with early onset disease

OBJECTIVE:Recent studies have suggested that a susceptibility gene located on chromosome 16 and designated IBD1 may contribute to the development of Crohns disease (CD). However, these findings were observed in predominantly non-Jewish populations; in the three studies where Ashkenazi Jews were included for analysis, the results have been widely divergent. Because Ashkenazi Jews are known to have a higher incidence of the disease than non-Jews, we sought to determine whether this previously reported linkage could be extended to the Ashkenazi population. In addition, we examined whether Ashkenazi Jewish patients with an early age of onset (≤21 yr) showed greater evidence of linkage to this locus.METHODS:Linkage analysis for the IBD1 region was performed on 123 Ashkenazi Jewish CD patients distributed among 53 families. Only patients with four Jewish grandparents were considered to be Jewish. Of the 123 Ashkenazi Jewish patients, 75 (61%) had an age of onset ≤21 yr.RESULTS:Ashkenazi Jews showed only modest evidence of linkage (nonparametric linkage 1.63, p = 0.05) to the IBD1 locus. However, when the Ashkenazi population was subdivided on the basis of age of onset, there was a striking increase in linkage in families where affected individuals had an age of onset ≤21 yr (nonparametric linkage 3.02, p = 0.002). In contrast, there was no evidence of linkage in the Jewish families where all affected individuals had an age of onset >21 yr.Conclusions:The IBD1 gene plays a greater role in conferring susceptibility to CD in Jews with early onset disease than in Jews with late onset disease.

Serum Vitamin K Concentration in Pediatric Patients Receiving Total Parenteral Nutrition

The only multivitamin preparation for total parenteral nutrition currently available in the United States that contains vitamin K is the pediatric formulation MVI-Pediatric. The recommended dose provides 200 micrograms of vitamin K1 per day to term infants and children up to 11 years old. This dose is well above the recommended dietary allowance of approximately 1 microgram/kg per day, but the losses of vitamin K during administration are unknown. We evaluated the stability of vitamin K1 in a standard total parenteral nutrition infusion and found that an average 72.7 +/- 4.9% of the original vitamin K1 was present after 24 hours. By using high-performance liquid chromatography with electrochemical reduction and fluorescence detection, we obtained the serum vitamin K1 concentrations in 11 pediatric patients receiving total parenteral nutrition with MVI-Pediatric (Rorer Pharmaceuticals, Fort Washington, PA) supplementation and in control children. The serum vitamin K1 concentration (19.3 +/- 12.2 ng/mL) in patients receiving MVI-Pediatric is significantly higher than that in control children 1.9 +/- 1.5 ng/mL (p < .001). Current practice results in excessive levels of vitamin K in pediatric patients.

Esophageal dysmotility in children breast-fed by mothers with silicone breast implants. Long-term follow-up and response to treatment.

Our aims were to determine the long-term clinical and manometric follow-up of 11 children with previously documented esophageal dysmotility, who had been breast-fed by mothers with silicone breast implants, their response to prokinetic agents, and to analyze changes in macrophage activation. Seven of 11 children had subjective clinical improvement. Weight/height ratios remained the same or improved in 9/11. Biopsies at follow-up endoscopy were either normal or demonstrated mild esophagitis in 8/10. LES and UES pressures and percent propagation were not significantly different at follow-up, while wave amplitude significantly increased. Following intravenous metoclopramide, LES pressure, percent propagation, and wave amplitude significantly increased while UES pressure was unchanged. Urinary neopterin significantly decreased at follow-up, while urinary nitrates were unchanged. Esophageal dysmotility is chronic in this group of children, suggesting persistent autonomic nervous system dysfunction. Prokinetic agents may be useful in long-term management. The decreasing urinary neopterin levels suggest that, ultimately, there may be improvement in esophageal motility.

LYMPHOCYTE RESPONSE TO SILICA AMONG OFFSPRING OF SILICONE BREAST IMPLANT RECIPIENTS

The current study evaluated immune response to silicon dioxide in children born to women with silicone breast implants. In part one of the study, the T lymphocytes of 21 of 24 such children were significantly stimulated by silicon dioxide (silica). Part two consisted of eleven children, four born preimplantation and seven born postimplantation. None of the preimplant offspring showed T cell responses to silica; five of the seven postimplant children were positive for T cell memory for silica. Part three was a blinded study based on statistically significant differences in T cell stimulation with silicon dioxide between postimplant children and controls. These findings indicate a common immune reaction, that of T cell memory, occurs in mothers and their children born after exposure to silicone mammary implants placed prior to pregnancy. Since not all such children were breast fed the result favors transplacental passage of immunogens such as silicone oligomers or through maternofetal cellular traffic.

Manometric Variations Following Spiral Myotomy for Long-Gap Esophageal Atresia

We have previously demonstrated that a spiral myotomy and delayed definitive procedure is a viable alternative for esophageal reconstruction in long-gap esophageal atresia. In this study we sought to determine whether this procedure leads to esophageal motility disturbances and to compare the manometric findings with controls as well as with those seen in children with esophageal atresia and primary anastomosis. Six beagles had esophageal transection and a spiral myotomy, one had esophageal transection without a myotomy, and two served as normal controls. Following esophageal reconstruction, esophageal manometry was studied in all dogs using a standard pull-through technique. We found that the three control dogs all had similar manometric findings with normal peristalsis. In contrast, the dogs with a spiral myotomy all had propagation of waves in the myotomized segment but termination of waves at the anastomotic site. There was delayed velocity through the myotomized segment and retrograde peristalsis distally. Finally, upper esophageal sphincter pressure was elevated, while lower esophageal sphincter pressure was similar to that in the normal dogs. These findings are similar to those described in children with primary anastomosis and suggest that (a) spinal myotomy is a good alternative to other esophageal replacement options in patients with long-gap esophageal atresia and that (b) the motility dysfunction observed in children with esophageal atresia following primary anastomosis may be secondary to the disruption of the vagus nerve and that may be part of the congenital abnormality or secondary to surgical trauma.

Impedance and extraesophageal manifestations of reflux in pediatrics

Extraesophageal manifestations of gastroesophageal reflux (GER) include such signs and symptoms as cough, asthma, respiratory symptoms, hoarseness, and laryngoscopic findings. We reviewed the role of MII‐pH monitoring in the evaluation of these findings in children to determine whether there is an association with pathological acid or nonacid reflux.