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Biomedical subjects

Frank M Ruemmele

Publications and source records attributed to Frank M Ruemmele.

10 recordsLinked to original sources

Microvillous inclusion disease (microvillous atrophy).

Microvillous inclusion disease (MVID) or microvillous atrophy is a congenital disorder of the intestinal epithelial cells that presents with persistent life-threatening watery diarrhea and is characterized by morphological enterocyte abnormalities. MVID manifests either in the first days of life (early-onset form) or in the first two months (late-onset form) of life. MVID is a very rare disorder of unknown origin, probably transmitted as an autosomal recessive trait. To date, no prevalence data are available. Ultrastructural analyses reveal: 1) a partial to total atrophy of microvilli on mature enterocytes with apical accumulation of numerous secretory granules in immature enterocytes; 2) the highly characteristic inclusion bodies containing rudimentary or fully differentiated microvilli in mature enterocytes. Light microscopy shows accumulation of PAS-positive granules at the apical pole of immature enterocytes, together with atrophic band indicating microvillus atrophy and, in parallel, an intracellular PAS or CD10 positive line (marking the microvillous inclusion bodies seen on electron microscopy). Intestinal failure secondary to diarrhea is definitive. To date, no curative therapy exists and children with MVID are totally dependent on parenteral nutrition. Long-term outcome is generally poor, due to metabolic decompensation, repeated states of dehydration, infectious and liver complications related to the parenteral nutrition. As MVID is a very rare disorder, which is extremely difficult to diagnose and manage, children with MVID should be transferred to specialized pediatric gastro-intestinal centers, if possible, a center equipped to perform small bowel transplantation. Early small bowel transplantation resulting in intestinal autonomy gives new hope for disease management and outcome.

Atrophy↗

Implication of TNF-related apoptosis-inducing ligand in inflammatory intestinal epithelial lesions.

BACKGROUND & AIMS: Few data exist on the molecular events causing intestinal epithelial destruction during inflammatory processes, such as inflammatory bowel disease (IBD). In this work, we analyzed the potential implication of tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) in these inflammatory lesions. METHODS: TRAIL and TRAIL-receptor expression were analyzed in normal, inflammatory ileum/colon and human intestinal epithelial cell (IEC) lines (HIEC), Caco-2, and HT-29 using RNase protection assay, real-time and reverse-transcription polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis. TRAIL-induced activation of NF-kappaB was determined by electrophoretic mobility shift assay. Caspase-recruitment domain (CARD)15 expression and interleukin-(IL)8 production were studied by RT-PCR and enzyme-linked immunosorbent assay. Apoptosis was monitored using Annexin-V/caspase-3 assays. RESULTS: Normal mature IEC expressed low TRAIL levels, whereas, in inflammatory lesions, TRAIL messenger RNA and protein were markedly up-regulated in IEC and lamina propria lymphocytes at levels comparable with trinitrobenzene sulfonic acid-induced colitis. Interferon-gamma and TNF-alpha potently induced TRAIL in IEC. In vitro analyses revealed a dual biologic effect of TRAIL on HIEC: Under noninflammatory conditions, TRAIL up-regulated via nuclear factor-kappaB CARD15 and IL-8, whereas, under inflammatory conditions, TRAIL became a potent inducer of apoptosis in HIEC, which was confirmed ex vivo using ileal organ cultures. TNF-alpha markedly increased the expression of the proapoptotic receptor TRAIL-R2. TRAIL-induced IEC apoptosis required a functional caspase cascade. CONCLUSIONS: TRAIL is a new inflammatory mediator implicated in the homeostasis of intestinal epithelial barrier functions. TRAIL is highly up-regulated in IEC in inflammatory ileum and colon. It may augment in an auto-/paracrine fashion the elimination of IEC via apoptosis.

Animals↗

Characteristics of inflammatory bowel disease with onset during the first year of life.

BACKGROUND: Inflammatory bowel disease (IBD) is recognized in young children, however, only rare data on onset and evolution are available in children younger than 1 year. In the present clinical study, we aimed to analyze characteristics and clinical course of children with very early onset IBD. We were particularly interested in the relationship between bacterial infections and the use of antibiotics before the onset of IBD. PATIENTS AND METHODS: The IBD database of Necker-Enfants-Malades-Hospital was screened for patients with IBD with disease onset during the first year of life and a follow-up of at least 2.5 years. Ten patients were identified during the period 1996-2002. RESULTS: All patients presented with rectal bleeding and had colonic involvement. Four patients had definitive diagnosis of Crohn disease; ulcerative or indeterminate colitis was seen in 2 and 4 children, respectively. Five of the patients had a positive history of neonatal or early-onset bacterial infection with use of antibiotics before onset of IBD, 4 patients were still breastfed and 3 just weaned when GI symptoms started. Seven patients had a severe onset of disease requiring bowel rest, parenteral nutrition and steroid medication, followed by azathioprine or cyclosporine medication. Surgery was necessary in 3 of 10 patients. Disease relapses were frequent and observed in 8 of 10 children. DISCUSSION: Very early onset IBD may reflect a subgroup of patients characterized by a particular sensitivity to modifications of the intestinal flora. Neonatal IBD was most often severe in presentation and evolution.

Age of Onset↗

Successful use of the new immune-suppressor sirolimus in IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome).

IPEX (immune-dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome is an autoimmune disorder with an often lethal outcome in spite of immunosuppressive therapy. We report the successful use of sirolimus in 3 patients with IPEX. The efficacy of sirolimus is probably due to its different mode of action compared to calcineurin-dependent agents.

Child↗

New perspectives for children with microvillous inclusion disease: early small bowel transplantation.

BACKGROUND: Microvillous inclusion disease (MVID) is a congenital intestinal epithelial cell disorder leading to lifelong intestinal failure. Despite long-term total parenteral nutrition, life expectancy is extremely reduced because of metabolic or septic complications or liver failure. METHODS: Twelve patients with early-onset MVID were evaluated between 1995 and 2002 for the possibility of small bowel transplantation (SbTx). Three patients died before they could be placed on the waiting list for SbTx, and one patient is still awaiting SbTx. SbTx was contraindicated in one patient. RESULTS: Seven of 12 patients (six boys and one girl) underwent transplantation (three SbTxs and four combined liver-SbTxs). Actuarial survival rates were 100% and 75% in the SbTx and combined liver-SbTx groups, respectively, with a mean follow-up of 3 years (1.1-8.5 years). In contrast, the survival rate was only 40% in the subgroup of five patients who did not undergo transplantation. After transplantation, all patients were weaned from parenteral nutrition: the five patients with an additional colon graft were weaned within 36 days as opposed to the others without colonic transplant who obtained full intestinal autonomy several months after transplantation. The only two surviving patients who did not undergo SbTx remain highly dependent on total parenteral nutrition, which is complicated by repeated episodes of metabolic decompensation. CONCLUSIONS: SbTx alone or in combination with the liver is highly successful in children with MVID, offering them a long-term perspective for the first time. Associated colon grafting markedly improves the outcome and quality of life after SbTx in patients with MVID.

Adolescent↗

[CD10 expression in a case of microvillous inclusion disease].

All over the causes of intractable diarrhea of infancy, microvillous inclusion disease is a rare congenital defect of intestinal brush border of unknown aetiology. An autosomal recessive inheritance is suggested by cases occurring in siblings and high incidence of consanguinity. The prognosis of the disease is extremely poor, as life can be sustained only by total parenteral nutrition. Combined bowel-liver or bowel transplantation is regarded as the only potentially life-saving therapy. We report a case of microvillous atrophy who undergone a combined bowel, colonic and liver transplantation, and discuss the tools allowing the light microscopic diagnosis.

Atrophy↗

Autoimmune enteropathy: molecular concepts.

PURPOSE OF REVIEW: Enteropathies causing temporary or permanent intestinal failure are a big diagnostic and therapeutic challenge for pediatric gastroenterologists. A now well-recognized and distinct entity is in the form of "autoimmune enteropathy (AIE)". Recent advances in the molecular workup of AIE gave first insight into the pathophysiology of AIE. In this review, we discuss new molecular concepts of AIE resulting in new diagnostic and therapeutic possibilities. RECENT FINDINGS: The identification of disease-causing mutations in the FOXP3 gene as a basic defect resulting in AIE points to a defect in regulatory T-cell homeostasis. FOXP3, primarily expressed by CD4+CD25+regulatory T cells, is a potent transcriptional suppressor and key modulator of T-cell functions. Nonfunctional FOXP3 leads to a tremendous hyperactivation of T cells, resulting in autoimmune aggression, such as seen in patients with immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked (IPEX) syndrome, a subgroup of AIE. There is recent evidence suggesting that a defect of regulatory factors other than FOXP3 might cause AIE. Anti-enterocyte autoantibodies, another main characteristic of AIE, seem to be of a secondary nature and can no more be considered as directly disease causing. SUMMARY: Based on the profound immune dysregulation, new treatment strategies emerged for AIE. The use of T-cell immunosuppressive drugs, such as tacrolimus combined to steroids, seems to be beneficial in some patients; however, long-term remission is not always possible. Bone marrow transplantation might be the treatment of choice in those patients who do not respond to immunosuppression; however, the first encouraging results remain to be confirmed since to date long-term outcome remains mixed.

Journal Article↗

Interleukin 15: a key to disrupted intraepithelial lymphocyte homeostasis and lymphomagenesis in celiac disease.

BACKGROUND & AIMS: The mechanism of intraepithelial lymphocyte hyperplasia, a hallmark of celiac disease, is unknown. We have investigated the role of epithelium-derived interleukin (IL)-15 in the alterations of epithelial homeostasis in refractory celiac sprue, a privileged situation to study the first step of lymphoid transformation and the contribution of intraepithelial lymphocytes to villous atrophy in celiac disease. METHODS: IL-15 expression was assessed in biopsy specimens and isolated enterocytes by combining immunohistochemistry, flow cytometry, and real-time quantitative polymerase chain reaction. The ability of IL-15 to induce growth and survival of clonal intraepithelial lymphocytes lacking surface CD3 and to induce their cytotoxicity and secretion of interferon gamma was tested using soluble IL-15 and coculture in the presence of epithelial cell lines expressing membrane IL-15. RESULTS: IL-15 was massively overexpressed not only in lamina propria but also in the intestinal epithelium of patients with active celiac disease and refractory celiac sprue. IL-15 was not secreted but delivered at the surface of enterocytes. IL-15 specifically induced the expansion and survival of the clonal abnormal intraepithelial lymphocytes that characterize refractory celiac sprue and triggered their secretion of interferon gamma and their cytotoxicity against intestinal epithelial cells. Comparable activating signals could be delivered by IL-15 expressed at the membrane of the T84 enterocyte cell line. CONCLUSIONS: These data provide strong evidence that uncontrolled overexpression of IL-15 in refractory celiac sprue perpetuates epithelial damage and promotes the emergence of T-cell clonal proliferations. Blocking IL-15 might prove useful to treat this severe complication of celiac disease.

Adult↗