Clinical Heterogeneity of Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-Linked Syndrome: A French Multicenter Retrospective Study

Objective

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is an autoimmune disease caused by mutations in the forkhead box protein 3 gene (FOXP3), which encodes a key regulator of immune tolerance. The aim of this study was to describe the clinical heterogeneity of the disease in a national French cohort.

Methods

Multicenter retrospective study of patients diagnosed with IPEX syndrome caused by mutations in FOXP3.

Results

Thirty children from 26 families were included. Age at disease onset (median [first to third quartile]) was 1.5 mo [0–84] and at death 3.5 years [0–10.5] (n = 15) indicating a high heterogeneity. Initial presentation was diarrhoea (68%), type 1 diabetes (T1D; 25%), skin lesions (7%) and nephropathy (3%). During the course of the disease the following main symptoms were observed: diarrhoea (100%), skin lesions (85%), T1DM (50%), severe food allergies (39%), haematological disorders (28%), nephropathies (25%), hepatitis (14%) as well as the presence of a variety of autoantibodies. Immunosuppressive mono- or combination therapy led to improvement in eight children. Three boys displayed a stable disease course without any immunosuppressive medication. Overall 10-year survival rate was 43% (42% in transplanted patients and 52% in patients on immunosuppressive therapy). Five out of 22 identified FOXP3 mutations have not been described yet: c.−23 + 1G > A, c.−23 + 5G > A, c.264delC, c.1015C > T and c.1091A > G. The first two produced atypical, attenuated phenotypes. Missense and frameshift mutations affecting the forkhead domain were associated with poor survival (Gehan–Wilcoxon p = 0.002).

Conclusion

The broad phenotypic heterogeneity of IPEX raises questions about modifying factors and justifies early FOXP3 sequencing in suspected cases.

Impacts of donor-specific anti-HLA antibodies and antibody-mediated rejection on outcomes after intestinal transplantation in children

AMR is a risk factor for graft failure after SBTx. We studied impact of DSAs and AMR in 22 children transplanted between 2008 and 2012 (11 isolated SBTx, 10 liver inclusive Tx, and one modified multivisceral Tx). Three patients never developed DSA, but DSAs were found in seven in the pre-Tx period and de novo post-Tx in 19 children. Pathology revealed cellular rejection (15/19), with vascular changes and C4d+. Patients were treated with IV immunoglobulins, plasmapheresis, and steroids. Rescue therapy included antithymocyte globulins, rituximab, eculizumab, and bortezomib. Pathology and graft function normalized in 13 patients, graft loss occurred in two, and death in seven. At the end of the follow-up, 15 children were alive (68%), 13 with functioning graft (59%). Prognosis factors for poor outcome after Tx were the presence of symptoms at AMR suspicion (P +.033). DSAs were often found following SBTx, mostly de novo. Resistant ACR or severe AMR is still difficult to differentiate, with a high need for immunosuppression in both. DSAs may precede development of severe disease and pathology features on the graft: relationship and correlation need to be better investigated with larger groups before and after Tx.

Assessment and outcome of children with intestinal failure referred for intestinal transplantation

BACKGROUND & AIMS

Chronic intestinal failure (CIF) requires long term parenteral nutrition (PN) and, in some patients, intestinal transplantation (ITx). Indications and timing for ITx remain poorly defined. In the present study we aimed to analyze causes and outcome of children with CIF.

METHODS

118 consecutive patients referred to our institution were assessed by a multidisciplinary team and four different categories were defined retrospectively based on their clinical course: Group 1: patients with reversible intestinal failure; group 2: patients unsuitable for ITx, group 3: patients listed for ITx; group 4: patients stable under PN. Analysis involved comparison between groups for nutritional status, central venous catheter (CVC) related complications, liver disease, and outcome after transplantation by using non parametric tests, Mann-Whitney tests, Kruskal-Wallis, Wilcoxon signed rank tests and chi square distribution for percentage.

RESULTS

118 children (72 boys) with a median age of 15 months at referral (2 months-16 years) were assessed. Etiology of IF was short bowel syndrome [n = 47], intractable diarrhea of infancy [n = 37], total intestinal aganglionosis [n = 18], and chronic intestinal pseudoobstruction [n = 17]. Most patients (89.8%) were totally PN dependent, with 48 children (40.7%) on home-PN prior to admission. Nutritional status was poor with a median body weight at -1.5 z-score (ranges: -5 to +2.5) and median length at -2.0 z-score (ranges: -5.5 to +2.3). The mean number of CVC inserted per patient was 5.2 (range 1-20) and the mean number of CRS per patient was 5.5 (median: 5; range 0-12) Fifty-five patients (46.6%) had thrombosis of ≥2 main venous axis. At admission 34.7% of patients had elevated bilirubin (≥50 μmol/l), and 19.5% had platelets <100,000/ml, and 15% had both. Liver biopsy performed in 79 children was normal (n = 4), or showed F1 or F2 fibrosis (n = 29), bridging fibrosis F3 (n = 20), or cirrhosis (n = 26). Group 1 included 10 children finally weaned from PN (7-years survival: 100%). Group 2 included 12 children with severe liver disease and associated disorders unsuitable for transplantation (7-years survival: 16.6%). Group 3 included 66 patients (56%) who were listed for small bowel or liver-small bowel transplantation, 62/66 have been transplanted (7 years survival: 74.6%). Factors influencing outcome after liver-ITx were body weight (p < .004), length (p < .001), pre-Tx bilirubin plasma level (p < .001) and thrombosis (p < .01) for isolated ITx, Group 4 included 30 children (25.4%) with irreversible IF considered as potential candidates for isolated ITx. Four children were lost from follow up and 3 died within 2 years (survival 88.5%). Among potential candidates, the following parameters improved significantly during the first 12 months of follow up: Body weight (p.0001), length (p < .0001) and bilirubin (p < .0001).

CONCLUSIONS

many patients had a poor nutritional status with severe complications especially liver disease. PN related complications were the most relevant indication for ITx, but also a negative predictor for outcome. Early patient referral for Tx-assessment might help to identify and separate children with irreversible IF from children with transient IF or uncomplicated long-term PN, allowing to adapt a patient-based treatment strategy including or not ITx.

Neonatal short bowel syndrome as a model of intestinal failure: physiological background for enteral feeding

Intestinal failure (IF) is a well identified clinical condition, which is characterised by the reduction of functional gut capacity below the minimum needed for adequate digestion and absorption of nutrients for normal growth in children. Short bowel syndrome (SBS) is the leading cause of IF in neonates, infants and young children usually as a result of extensive intestinal resection during the neonatal period. Simultaneously maintaining optimal nutritional status and achieving intestinal adaptation is a clinical challenge in short bowel patients. Both growth and development of the child as well as gut adaptation should be considered synergistically as primary outcome parameters. Enteral nutrition (EN) can be introduced orally and/or by tube feeding (TF). Several controversies over nutritional treatment of children with SBS related intestinal failure remain. As reported from different centres around the world, most practices are more "experienced based" rather than "evidence based". This is partly due to the small number of patients with this condition. This review (based on a consensus) discusses the physiological principles and nutritional management, including the type of diet and route of delivery. Perspectives in optimizing intestinal adaptation and reducing the consequences of small intestinal bacterial overgrowth are also discussed.

Vitamin D: still a topical matter in children and adolescents. A position paper by the Committee on Nutrition of the French Society of Paediatrics

The aims of the present position paper by the Committee on Nutrition of the French Society of Paediatrics were to summarize the recently published data on vitamin D in infants, children and adolescents, i.e., on metabolism, physiological effects, and requirements and to make recommendations on supplementation after careful review of the evidence. Scientific evidence indicates that calcium and vitamin D play key roles in bone health. The current evidence, limited to observational studies, however, does not support other benefits for vitamin D. More targeted research should continue, especially interventional studies. In the absence of any underlying risk of vitamin D deficiency, the recommendations are as follows: pregnant women: a single dose of 80,000 to 100,000 IU at the beginning of the 7th month of pregnancy; breastfed infants: 1000 to 1200 IU/day; children less than 18 months of age, receiving milk supplemented with vitamin D: an additional daily dose of 600 to 800 IU; children less than 18 months of age receiving milk not supplemented with vitamin D: daily dose of 1000 to 1200 IU; children from 18 months to 5 years of age: 2 doses of 80,000 to 100,000 IU every winter (November and February). In the presence of an underlying risk of vitamin D deficiency (dark skin; lack of exposure of the skin to ultraviolet B [UVB] radiation from sunshine in summer; skin disease responsible for decreased exposure of the skin to UVB radiation from sunshine in summer; wearing skin-covering clothes in summer; intestinal malabsorption or maldigestion; cholestasis; renal insufficiency; nephrotic syndrome; drugs [rifampicin; antiepileptic treatment: phenobarbital, phenytoin]; obesity; vegan diet), it may be justified to start vitamin D supplementation in winter in children 5 to 10 years of age as well as to maintain supplementation of vitamin D every 3 months all year long in children 1 to 10 years of age and in adolescents. In some pathological conditions, doses of vitamin D can be increased. If necessary, the determination of 25(OH) vitamin D serum concentration will help determine the level of vitamin D supplementation.

The efficacy of exclusive nutritional therapy in paediatric Crohn's disease, comparing fractionated oral vs. continuous enteral feeding

BACKGROUND

Nutritional therapy has an established role as induction therapy in paediatric Crohn's disease. However, compliance is the main difficulty and may be greatly influenced by the administration route.

AIM

To analyse the efficiency of exclusive nutrition to induce remission in children with Crohn's disease comparing fractionated oral vs. continuous enteral feeding.

METHODS

The medical records of 106 patients treated by exclusive nutritional therapy [Modulen IBD (R)] by either oral or continuous enteral route were reviewed retrospectively. Comparative analyses of remission rates, changes in anthropometry, Paediatric Crohn's disease Activity Index (PCDAI), laboratory indices and compliance rates were performed.

RESULTS

On exclusive enteral nutrition, at 8 weeks, 34/45 patients achieved remission in the oral group (75% on intention-to-treat analysis) and 52/61 (85%) in the enteral nutrition group (P = 0.157). All patients showed a significant decrease in disease severity assessed by PCDAI (P < 0.0001) and significant improvements in anthropometric measures and inflammatory indices. No difference was observed whether Modulen IBD was administered orally or by continuous enteral feeding, apart from weight gain, which was greater in the enteral group (P = 0.041). In a subgroup of patients, mucosal healing was evidenced on follow-up endoscopies showing a clear correlation to remission. Compliance rates (87% and 90%) were similar. Nevertheless, noncompliant patients had lower mucosal healing and remission rates.

CONCLUSIONS

These retrospective data suggest that the use of fractionated oral nutritional therapy might be as efficacious as continuous enteral administration to induce remission and mucosal healing in children with Crohn's disease. However, appropriate prospective clinical trials are needed to confirm these findings.

[Capsule endoscopy in children: which are the best indications?]

BACKGROUND AND STUDY AIMS

Capsule endoscopy (CE) is a novel and noninvasive means of investigating the small bowel. In children, the best CE indications have not yet been fully appraised. The aim of this study was to evaluate the diagnostic yield of CE in different pediatric pathologies.

PATIENTS AND METHODS

We retrospectively reviewed every CE performed in children in two French pediatric hospitals between March 2002 and June 2009. Seventy-nine CEs were performed on 70 children (mean age, 10.6 years; range, 2.2-18.0); 52 boys and 18 girls. The indications were iron deficiency anemia (24%), obscure gastrointestinal bleeding (14%), polyposis syndromes (16%), suspected Crohn disease (15%), unresponsive Crohn disease (10%), graft-versus-host disease (10%), and other (10%).

RESULTS

Of the 79 CEs, 69 reached the cecum (87%). Only one occlusion occurred in a case of stenosing Crohn disease, requiring surgical removal. In addition, technical difficulties led to an incomplete small bowel study in 12 cases (16%). The CE showed small bowel lesions in 42 cases (53%). The diagnostic yield was 27% in obscure gastrointestinal bleeding, 37% in iron-deficiency anemia, 42% in suspected Crohn disease, 88% in unresponsive Crohn disease, 62% in polyposis syndromes, and 88% in graft-versus-host disease.

CONCLUSION

In children, CE is well tolerated and can be performed in children as young as 2.2 years of age. Its diagnostic yield is highest in polyposis syndromes, unresponsive Crohn disease, and graft-versus-host disease.

Normal oxidative phosphorylation in intestinal smooth muscle of childhood chronic intestinal pseudo-obstruction

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) is a severe disease of the digestive tract motility. In pediatric population, CIPO remains of unknown origin for most patients. Chronic intestinal pseudo-obstruction is also a common feature in the course of mitochondrial oxidative phosphorylation disorders related for some patients to mutations in TYMP, POLG1, mtDNA tRNA(leu(UUR)) or tRNA(lys) genes. We hypothesized that CIPOs could be the presenting symptom of respiratory chain enzyme deficiency and thus we investigated oxidative phosphorylation in small bowel and/or colon smooth muscle of primary CIPO children.

METHODS

We studied eight children with CIPO and 12 pediatric controls. We collected clinical, radiological and pathological data and measured respiratory chain enzymatic activity in isolated smooth muscle of the small bowel and/or the colon. We also sequenced TYMP, POLG, mtDNA tRNA(leu(UUR)) and tRNA(lys) genes.

KEY RESULTS

Neither pathological nor radiological data were in favor of a mitochondrial dysfunction. No respiratory chain enzyme deficiency was detected in CIPO children. In myogenic CIPO, respiratory enzymes and citrate synthase activities were increased in small bowel and/or colon whereas no abnormality was noted in neurogenic and unclassified CIPO. Levels of enzyme activities were higher in control small bowel than in control colon muscle. Sequencing of TYMP, POLG, mtDNA tRNA(leu(UUR)) and tRNA(lys) genes and POLG gene did not reveal mutation for any of the patients.

CONCLUSIONS & INFERENCES

The normal enzymatic activities as the lack of radiological and genetic abnormalities indicate that, at variance with adult patients, oxidative phosphorylation deficiency is not a common cause of childhood CIPO.

The use of body mass index for measurement of fat mass in children is highly dependant on abdominal fat

We examined the relationship between body fat and body mass index (BMI) in a multiethnic population of obese children. BMI z-scores were compared to DEXA measures of whole body composition and regional fat distribution. Fat mass index (FMI) was best predicted by the equation: 1/[(0.159- 0.013 x percentile of total abdominal fat)- (0.01 x BMI z-score)], where percentile of abdominal fat ranges from 1 to 5. Predicted FMI had high agreement with FMI measured by DEXA. There were no detectable differences in this relation between different ethnic groups. Both BMI and abdominal fat should be used as a proxy to determine adiposity.

Clinical evidence for immunomodulatory effects of probiotic bacteria

Close, tightly orchestrated interactions between the intestinal epithelium and the mucosa-associated immune system are critical for normal intestinal absorptive and immunological functions. Recent data indicate that commensal intestinal microbiota represents a major modulator of intestinal homeostasis. This review analyzes the process of intestinal colonization and the interaction of microbiota with the intestinal epithelium and mucosal immune system, with special reference to the first years of extrauterine life. Dysregulation of the symbiotic interaction between intestinal microbiota and the mucosa may result in a pathological condition with potential clinical repercussions. Based on the concept that there is a beneficial and symbiotic relation between the host and endogenous microbiota, strategies aimed at directly modulating intestinal microbiota with regard to disease prevention or treatment have been developed. One strategy involves administering viable probiotic bacteria. Clinical evidence for the beneficial effect of probiotics in the prevention and/or treatment of necrotizing enterocolitis, infectious and antibiotic-associated diarrhea, allergic diseases, and inflammatory bowel disorders is reviewed herein.

Is intestinal transplantation the future of children with definitive intestinal insufficiency?

Intestinal transplantation (IT) is the newest and most difficult of organ transplantations. The first ever (1987) and the longest surviving (1989) IT were performed in our institution. However, IT still has to demonstrate its benefit to children on long-term parenteral nutrition (PN). We tried to clarify this aspect by looking back at our 13 years' experience.

PATIENTS

From 1994 to December 2007, 74 IT were performed in 69 children, 39 with an isolated small bowel (IT), 35 combined with a liver transplant (LITx). The indications were: short bowel syndrome (n = 25), congenital mucosal diseases (n = 22), and motility disorders (n = 22). Median age at transplantation was 5 years (1 - 17 years). Follow-up was 1 to 12 years (median 5 years).

RESULTS

Thirty-one children have a functioning graft (42 %), 15/39 IT, 16/35 LITx. They are at home without PN, with a good quality of life. One child is PN-dependent 1.5 years post IT. Post IT, 16 children were detransplanted: 12 early on (1 for mechanical complications, 11 because of resistant rejection; 3 less than 3 years, one 9 years post SBT (chronic rejection). In 2 noncompliant teenagers, PN was reintroduced (one was detransplanted later on). Several years post LITx, 2 children underwent bowel detransplantation due to an acute viral infection complicated with rejection. Twenty-two children died (32 %, 8 IT, 14 LITx), 18 early on from infectious or surgical complications, 4 more than 1 year post IT, 3 after retransplantation (1 in another unit). Bad prognostic factors are multiple previous surgeries, an older age (> 7 y), and chronic intestinal pseudo-obstruction.

DISCUSSION

Complications post IT are frequent and life-threatening, especially early on: rejection (IT), infections (LITx). Later on, the rate of complications decreases but remains significant, especially in noncompliant patients. However we describe here a 13-year learning curve; the recent results are encouraging with regard to control of rejection and viral infections.

CONCLUSION

Intestinal transplantation is indicated only in selected patients in whom long-term PN cannot be performed safely any more. In every child with intestinal insufficiency, the therapeutic strategy must be discussed early on in order to perform IT at the right time under optimal conditions. IT should evolve from being a "rescue" procedure to becoming a true therapeutic option.

Cutaneous manifestations of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome

BACKGROUND

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder characterized by neonatal autoimmune enteropathy, diabetes and thyroiditis, food allergies and skin rash. IPEX syndrome is caused by mutations in FOXP3, a master control gene of regulatory T cells (Tregs), resulting in absent or dysfunctional Tregs. Data in the literature are scarce and the cutaneous manifestations are rarely depicted.

OBJECTIVES

To evaluate the frequency and characteristics of cutaneous manifestations found in IPEX.

METHODS

Retrospective single-centre study of a case series of IPEX. Patients' data were retrieved from medical files and numerous parameters concerning general and cutaneous characteristics of the disease were recorded.

RESULTS

Ten children with IPEX were studied. Cutaneous involvement was present in seven of 10 children; age at onset was 0-4 months, median 1.5. All patients presented with atopic dermatitis (AD). Three presented more psoriasiform lesions. Eczema was severe; most affected areas were lower limbs, trunk and face. Pruritus was present in four of seven, and painful fissurary cheilitis in four of seven. Hyper-IgE was found in seven of 10 and hypereosinophilia in five of 10. Skin biopsies showed eczematiform or psoriasiform features. Affected patients were improved by dermocorticoids; no clear improvement was obtained with immunosuppressive regimens. Other features were urticaria secondary to food allergies and staphylococcal sepsis, mostly Staphylococcus aureus and catheter related.

CONCLUSIONS

AD seems to be a frequent finding in IPEX syndrome, which is characterized by Treg anomalies. This hints to a possible role of Tregs in AD, which is then discussed in this study.

Evaluation of c4d deposition and circulating antibody in small bowel transplantation

Antibody-mediated rejection (AMR) consensus criteria are defined in kidney and heart transplantation by histological changes, circulating donor-specific antibody (DSA), and C4d deposition in affected tissue. AMR consensus criteria are not yet identified in small bowel transplantation (SBTx). We investigated those three criteria in 12 children undergoing SBTx, including one retransplantation and four combined liver-SBTx (SBTx), with a follow-up of 12 days to 2 years. All biopsies (91) were evaluated with a standardized grading scheme for acute rejection (AR), vascular lesions and C4d expression. Sera were obtained at day 0 and during the follow-up. C4d was expressed in 37% of biopsies with or without AR, but in 50% of biopsies with severe vascular lesions. In addition, vascular lesions were always associated with AR and a poor outcome. All children with AR (grade 2 or 3) observed before the third month died or lost the graft. DSA were never found in any studied sera. We found no evidence that C4d deposition was of any clinical relevance to the outcome of SBTx. However, the grading of vascular lesions may constitute a useful marker to identify AR that is potentially resistant to standard treatment, and for which an alternative therapy should be considered.

Long-term outcome, growth and digestive function in children 2 to 18 years after intestinal transplantation

OBJECTIVE

Small bowel (SB) transplantation (Tx), long considered a rescue therapy for patients with intestinal failure, is now a well recognised alternative treatment strategy to parental nutrition (PN). In this retrospective study, we analysed graft functions in 31 children after SBTx with a follow-up of 2-18 years (median 7 years).

PATIENTS

Twelve children had isolated SBTx, 19 had combined liver-SBTx and 17 received an additional colon graft. Growth, nutritional markers, stool balance studies, endoscopy and graft histology were recorded every 2-3 years post-Tx.

RESULTS

All children were weaned from PN after Tx and 26 children remained PN-free. Enteral nutrition was required for 14/31 (45%) patients at 2 years post-Tx. All children had high dietary energy intakes. The degree of steatorrhoea was fairly constant, with fat and energy absorption rates of 84-89%. Growth parameters revealed at transplantation a mean height Z-score of -1.17. After Tx, two-thirds of children had normal growth, whereas in one-third, Z-scores remained lower than -2, concomitant to a delayed puberty. Adult height was normal in 5/6. Endoscopy and histology analyses were normal in asymptomatic patients. Chronic rejection occurred only in non-compliant patients. Five intestinal grafts were removed 2.5-8 years post-Tx for acute or chronic rejection.

CONCLUSIONS

This series indicates that long-term intestinal autonomy for up to 18 years is possible in the majority of patients after SBTx. Subnormal energy absorption and moderate steatorrhoea were often compensated for by hyperphagia, allowing normal growth and attainment of adult height. Long-term compliance is an important pre-requisite for long-term graft function.

Energy cost of fever in children on total parenteral nutrition

The aim of the study was to measure the changes in energy expenditure (EE) and respiratory quotient (RQ) induced by fever in children receiving total parenteral nutrition (TPN). Ten children aged 1-16 years (weight for height: 104.5 +/- 13%) were included. They underwent two EE recordings of 3 h duration using indirect calorimetry, during a febrile (38.9 +/- 0.5 degrees C) and afebrile conditions, after parameters (nutritional intake, ambient temperature) being equal. The EE, (febrile phase) was significantly higher than the EE(2) (afebrile) (2.13 +/- 0.48 vs 1.78 +/- 0.42 kcal/kg/h; P < 0.01). Increase in EE was significantly correlated with body temperature (r = 0.92, P < 0.001). The slope of the regression line indicates an increase of 16.2% in EE per degree of fever. By dividing the individual increase in EE by the individual increase in temperature, the energy expenditure during fever is 11.3% per unit rise ( degrees C). During the febrile phase urinary nitrogen excretion was significantly higher (280 +/- 90 vs 210 +/- 70 mg/kg fat free mass/day, P < 0.02). The RQ during the febrile phase (0.90 +/- 0.13) did not differ significantly from mean RQ during the afebrile phase (0.95 +/- 0.07). Fever due to infection or inflammatory process is partly responsible for an hypermetabolic state including increased EE.

Efficacy of methotrexate in pediatric Crohn's disease: a French multicenter study

BACKGROUND

Immunosuppressors play a major role in maintaining remission in Crohn's disease (CD). In patients who do not tolerate or escape therapy with azathioprine (AZA)/6-mercaptopurine, there is a marked need for other immunosuppressive drugs. The aim of the present study was to evaluate the efficacy and safety of methotrexate (MTX) in children with active CD.

METHODS

In a retrospective multicenter (n = 3) study, the efficacy of MTX to induce complete remission or a clinical improvement was analyzed in 61 children with active CD.

RESULTS

CD was diagnosed at a mean age of 11.1 +/- 2.3 years, and MTX was introduced 3.1 +/- 2.2 years after diagnosis. Indications to use MTX were a nonresponse to or relapse under AZA (n = 42) or AZA intolerance/toxicity (n = 19). MTX improved or induced complete remission in 49 patients (80%), of whom 18 (29.5%) relapsed after 13 +/- 10 months of treatment. Under MTX medication, complete remission was observed in 39%, 49%, and 45% at 3, 6, and 12 months, respectively. Follow-up over at least 24 months in 11 children confirmed a sustained remission on MTX monotherapy up to 40 months. Adverse reactions were observed in 14 patients (24%), requiring discontinuation of MTX in 6 children (10%) (liver enzyme elevation, n = 2; varicella-zoster, n = 1; nausea, n = 3). MTX allowed corticosteroid discontinuation in 36 patients.

CONCLUSIONS

MTX improved the clinical course in most pediatric CD patients who escaped or did not tolerate AZA. Short-time toxicity of MTX resulted in drug discontinuation in <10%. These data point to a beneficial and safe use of MTX in the treatment of pediatric CD.

Microbial induction of CARD15 expression in intestinal epithelial cells via toll-like receptor 5 triggers an antibacterial response loop

With the discovery of CARD15 as susceptibility gene for Crohn's disease (CD) a first link to a potential defect in the innate immune system was made. In this work we aimed to analyze enterocyte NOD2/CARD15 expression and regulation in response to bacterial motifs and the consequences of the most common CD-specific CARD15 mutation on antibacterial responses of normal intestinal epithelial cells (IEC). Under normal conditions, IEC lines and ileal enterocytes did not express NOD2/CARD15 mRNA or protein, contrary to IEC derived from inflammatory CD sections. In vitro analyses revealed that the simple contact with non-pathogenic commensal E. Coli K12 was sufficient to induced NOD2/CARD15 mRNA and protein in human IEC (HIEC). We identified bacterial flagellin interacting with TLR5 as major motif in this regulation of NOD2/CARD15. E. Coli mutants not expressing flagellin (DeltaFliC) failed to induce CARD15. Similarly, in HIEC transfected with a plasmid encoding dominant negative TLR5, no CARD15 induction was observed after K12 contact. Isolated TLR2 or TLR4 stimulation had no or only a marginal effect on NOD2/CARD15 expression. NOD2/CARD15 negative HIEC were unresponsive to muramyl dipeptide (MDP), but once NOD2/CARD15 was induced, HIEC and Caco2 cells responded to intra or extracellular MDP presentation with the activation of the NFkB pathway. IEC transfected with the Crohn-specific CARD15 mutant (F3020insC, FS) failed to activate NFkB after MDP-challenge, in contrast to CARD15WT IEC. In response to MDP, IEC induced a massive antibacterial peptide (ABP) response, seen in the apical release of CCL20. This was completely abolished in IEC carrying CARD15FS. These data suggest a critical role of NOD2/CARD15 in the bacterial clearance of the intestinal epithelium while CD-specific mutated NOD2/CARD15 causes an impaired epithelial barrier.

Factors Influencing Outcome After Intestinal Transplantation in Children

We evaluated 131 patients (6 months-14 years) who experienced 21 deaths before listing, 11 continuing on the waiting list, 38 well on home parenteral nutrition, 6 off parenteral nutrition and 59 transplanted (20 girls) aged 2.5 to 15 years, (18 >7 years). They received cadaveric isolated intestine (ITx, n = 31) or liver-small bowel (LITx, n = 32), including right colon (n = 43; 23 LITx) for short bowel (n = 19), enteropathy (n = 20), Hirschsprung (n = 14), or pseudo-obstruction (n = 6). Treatment included tacrolimus, steroids, azathioprine, or interleukin-2 blockers. After 6 months to 10.5 years, the patient and graft survivals were 75% and 54%. Sixteen patients (10 LITx) died within 3 months from surgery (n = 3), bacterial (n = 5) or fungal (n = 6) sepsis, or posttransplant lymphoproliferative disorder (n = 2). Rejection occurred in 27 patients, including 10 steroid-resistant episodes requiring antilymphoglobulins. The grafts were removed due to uncontrolled rejection in seven ITx recipients. Surgical complications were observed in 38 recipients (25 LSBTx) within 2 months, including bacterial (n = 22) or fungal (n = 11) sepsis, cytomegalovirus disease (n=12), adenovirus (n = 11), or posttransplant lymphoproliferative disorder (n = 12). Forty-two children (19 LSBTx) are alive. Weaning from parenteral nutrition was achieved after 42 days (median). Factors related to death or graft loss were pre-Tx surgery (P < .01), pseudo-obstruction (P < .01), age over 7 years (P < .03), fungal sepsis (P < .03), steroid resistant rejection (P < .05), hospitalized versus home patient (P < .01), and retransplantation (P < .05). Colon transplant did not affect the outcome. Interleukin-2 blockers improved isolated ITx (P < .05). Early referral and close monitoring of intestinal failure and related disorders are mandatory to achieve successful ITx.

Severe dysimmune cytopenia in children treated with tacrolimus after organ transplantation

Rare cases of dysimmune phenomena after solid organ transplantation were described in the past. In the present series, we describe six children who developed severe dysimmune anemia or thrombocytopenia while treated with tacrolimus after liver or small bowel transplantation. All patients were off steroids or under low doses alternate day steroid medication when dysimmune cytopenia developed. All patients had positive anti-platelets antibodies and/or Coombs' positive anemia. Therapy was successful in all six patients with a rapid response to corticosteroids in three children, and to anti-CD20 monoclonal antibodies (rituximab) in the three others. The pathogenesis of these rare dysimmune/autoimmune disorders might be related to the interference of tacrolimus with T-cell functions and/or the endogenous control mechanisms of T-lymphocyte activation and down-regulation. Although rare, these complications must be known when discussing protocols of immunosuppression.