Origin of cardiac mucosa: ontogenic consideration.

The origin and histology of the cardiac mucosa remains controversial. The classical concept that the cardiac mucosa is of gastric origin has been challenged by those who advocate that the cardiac mucosa results from a metaplastic esophageal process. Some regard cardiac mucosa as consisting solely of pure mucous glands, whereas others accept the presence of isolated parietal cells within the mucous gland (mixed glands). In this study, we have clarified the presence and site of origin of the cardiac mucosa and its histological composition. To do so we studied the microscopic characteristics of the gastric side of the squamous-columnar junction (SCJ) of 77 autopsied fetuses of different gestational ages (prenatal group) and of infants, young children, and adolescents (postnatal group). We evaluated the presence or absence of a transitional zone, defined as the area between the squamous esophageal and oxyntic mucosa, the glandular composition of the transitional zone (i.e., pure mucous and mixed glands), and the presence or absence of inflammation. Our study revealed that a transitional zone with the microscopic characteristics of cardiac mucosa was universally present at the SCJ. The microscopic characteristics of this zone varied with age. Both pure mucous and mixed glands were observed. We conclude that the cardiac mucosa is partially if not entirely the result of normal embryonic gastric development. Both mucous and mixed glands constitute normal components of the cardiac mucosa.

Oral tacrolimus treatment of severe colitis in children.

OBJECTIVE: To evaluate the efficacy of oral tacrolimus as an induction agent in steroid-refractory severe colitis. STUDY DESIGN: Open-label, multicenter trial of oral tacrolimus in patients with severe colitis. Patients not responding to conventional therapy received tacrolimus, 0.1 mg/kg/dose given twice a day, and the dosage was adjusted to achieve blood levels between 10 and 15 ng/mL. Response was defined as improvement in a number of clinical parameters (including abdominal pain, diarrhea, rectal bleeding, and cessation of transfusions). Patients who responded by 14 days continued to receive tacrolimus, and 6-mercaptopurine or azathioprine was added as a steroid-sparing agent 4 to 6 weeks after the tacrolimus was instituted. RESULTS: Fourteen patients were enrolled in the study. One patient elected to withdraw after 48 hours. Of the 13 remaining, 9 (69%) responded and were discharged. Tacrolimus was continued for 2 to 3 months in the responders, except for 1 patient who was given tacrolimus for 11 months. After 1 year of follow-up, only 5 (38%) patients were receiving maintenance therapy; the other 4 responders had undergone colectomy. CONCLUSION: Although tacrolimus is effective induction therapy for severe ulcerative or Crohn's colitis, fewer than 50% of patients treated will successfully achieve a long-term remission.

A multicenter trial of 6-mercaptopurine and prednisone in children with newly diagnosed Crohn's disease.

BACKGROUND & AIMS: Clinical experience suggests that 6-mercaptopurine (6-MP) is effective therapy for children with active steroid-dependent Crohn's disease (CD). We report the results of a prospective, placebo-controlled, multicenter trial evaluating the combination of 6-MP and prednisone as therapy for children with newly diagnosed moderate-to-severe CD. METHODS: Fifty-five children (age, 13+/-2 years) were randomized to treatment with 6-MP (1.5 mg x kg(-1) x day(-1)) or placebo within 8 weeks of initial diagnosis. Both groups also received prednisone (40 mg/day). Prednisone dosage adjustments were based on a defined schedule determined by the change in a subject's disease activity score, and steroid administration was discontinued as remission was achieved. Study treatment with 6-MP or placebo continued for 18 months. RESULTS: Groups were comparable for age, sex, and site and activity of disease. In the 6-MP group, the duration of steroid use was shorter (P<0.001) and the cumulative steroid dose lower at 6, 12, and 18 months (P<0.01). Although remission was induced in 89% of both groups, only 9% of the remitters in the 6-MP group relapsed compared with 47% of controls (P = 0.007). Growth was comparable in both groups. No clinically significant adverse events occurred, although mild leukopenia and increases in aminotransferase activity were noted in the 6-MP group. CONCLUSIONS: Addition of 6-MP to a regimen of corticosteroids significantly lessens the need for prednisone and improves maintenance of remission. 6-MP should be part of the initial treatment regimen for children with newly diagnosed moderate-to-severe CD.

Prevalence and pathogenesis of pancreatic acinar tissue at the gastroesophageal junction in children and young adults.

BACKGROUND: Pancreatic acinar tissue (PAT) at the gastroesophageal junction (GEJ) has been reported in 3% of adults with Barrett esophagus (BE) and in 24% of healthy subjects. The pathogenesis of this ectopic tissue is controversial. Both an acquired metaplastic process in the setting of BE and a congenital abnormality have been suggested in adults. OBJECTIVE: To clarify the origin of PAT at the GEJ. METHODS: We reviewed material obtained from the GEJ in 69 children and young adults. Each specimen was evaluated by 3 levels stained with hematoxylin-eosin for the presence of PAT, BE, esophagitis, and gastritis. Selected cases were also examined with immunohistochemical stains for lipase, trypsin, and amylase. RESULTS: In 16% of the study population, PAT was present at the GEJ and was not associated with BE. The prevalence of esophagitis and/or gastritis did not vary significantly between patients with and without PAT. CONCLUSIONS: Our data suggest that PAT at the GEJ develops independently of inflammation and is, therefore, likely to be congenital.

Rapidly progressive cholestasis: An unusual reaction to amoxicillin/clavulanic acid therapy in a child.

Hepatotoxity associated with amoxicillin/clavulanic acid is usually a self-limited disease with complete recovery. We report a rapidly progressing liver disease with ductopenia and portal fibrosis in a 3-year-old boy treated with Augmentin.

Ontogeny of renal dysplasia in Ivemark syndrome: light and immunohistochemical characterization.

Ivemark syndrome is a rare sporadic or autosomal recessive disorder characterized by pancreatic fibrosis, renal dysplasia and hepatic dysgenesis. There have been no data describing the renal changes during embryologic development in this syndrome. In this report, we document the pathological findings of the kidney in three subjects with Ivemark syndrome: 6 months, 21 weeks and 16 weeks, respectively. Kidneys of subjects and age-matched controls were examined by light microscopy and immunohistochemically for cytokeratin, AE1/AE3 and epithelial membrane antigen. Renal dysplasia in Ivemark syndrome becomes apparent at 16 weeks of gestation and progresses thereafter in severity. It is characterized by disturbance in glomerular differentiation, delay in tubular differentiation and abnormal expression of epithelial markers in glomeruli and tubules. Cytokeratin and epithelial membrane antigen expression of cysts is similar to that of the collecting ducts.

Endoscopic screening for dysplasia and mucosal aneuploidy in adolescents and young adults with childhood onset colitis.

OBJECTIVES: In adults, the premalignant nature of ulcerative colitis (UC) has long been accepted. Currently there is increasing concern that Crohn's disease (CD) may be equally premalignant. As a consequence, most adults with long-standing UC and many with chronic CD are enrolled in ongoing endoscopic cancer surveillance programs. In contrast, the risk of colonic cancer in adolescents and young adults with either form of colitis is less well recognized, and the need for dysplasia and cancer screening in this population has not been systematically evaluated. We therefore report the prospective results of colonoscopic cancer screening in such a young population. METHODS: Thirty-five adolescents and young adults with long-standing colitis (18 UC, 17 CD; 21 +/- 3 yr old, 11 +/- 3 yr colitis duration) underwent colonoscopic cancer screening. All had multiple biopsies for flow cytometry and light microscopy. RESULTS: Seven subjects had aneuploidy (3/18 UC, 4/17 CD). Of these seven, only two had dysplasia [one high grade (UC), one low grade (CD)]. One additional subject had indefinite dysplasia with normal flow cytometry. The remaining 27 subjects had both normal flow cytometry and light microscopy. Five of the seven aneuploid subjects underwent surgery within 1 yr of screening. Four, including both subjects with dysplasia, had no evidence of colon cancer at surgery. However, a 24-yr-old female with a 14-yr history of UC and no evidence of dysplasia or cancer at screening had a Dukes C adenocarcinoma. CONCLUSIONS: Adolescents and young adults with childhood onset UC or CD are at risk for aneuploidy, dysplasia, and colon cancer. Aneuploidy can be evident 10 yr after the onset of colitis and in patients as young as 16 yr of age. Therefore, the risk for colon cancer in patients with childhood onset colitis must be based on the duration of the illness, not on their chronological age. Incorporation of flow cytometry into an endoscopic screening protocol appears to enhance the ability to identify individuals at highest risk for colon cancer.

Highly destructive perianal disease in children with Crohn's disease.

The perianal complications of Crohn's disease (CD) seen in children and adolescents include skin tags, anal fissures, fistulae, and abscesses. While these lesions are often chronic and variably responsive to medical therapy, only rarely are they severely destructive. In this report, we characterize the frequency, severity, and clinical course of a highly destructive form of perianal disease (HDPD) that we have noted in a number of children and adolescents with Crohn's disease. A database containing records from 350 children with inflammatory bowel disease was reviewed to identify all children with CD treated between 1970 and 1993. For each, the occurrence or absence of significant perianal pathology, including fistula, abscess, and HDPD, was determined. Pertinent clinical details were recorded for all patients. In addition, the clinical characteristics of those children with HDPD were compiled, and the courses of those with HDPD characterized. A search of the database identified 230 children and adolescents with CD followed for a total of 1,518 patient years. Sixty-seven of these patients (29% of the CD population) had significant perianal pathology. This included 6 with HDPD, 8 with complicated fistulae [rectourethroperineal (1), rectovaginal (1), rectolabial (2), and multiple communicating perineal (4)], and 53 with simple perianal fistulae or abscesses. All six with HDPD had deeply destructive perineal ulcerations, marked undermining of the perineal and perirectal tissues, and copious exudate, and often there was a deeply cleaved or fileted perineum on separating the buttocks. Two children with HDPD had fecal incontinence.

Characterization of hepatic abnormalities in children with inflammatory bowel disease.

: We sought to characterize the incidence, nature, and course of liver disease in children with inflammatory bowel disease (IBD). Chart review identified 555 subjects (318 Crohn's disease [CD], 237 ulcerative colitis [UC]). An alanine aminotransferase measurement of ≥80 U/L was used to identify the presence of a hepatic abnormality. Seventy-five patients (47 CD, 28 UC) had at least one ALT level ≥80 U/L. Persistent ALT elevation (>6 months) was found in 14 patients: 10 with sclerosing cholangitis (SC) (eight UC, two CD) and four with autoimmune chronic active hepatitis (CAH) (one UC, three CD). One patient with SC has had hepatic transplantation, and one other has end-stage liver disease. The remainder are clinically well. Two patients with CAH have developed cirrhosis. Nonpersisting ALT elevations (<250 U/L) were noted during disease course in 61 patients and were associated with medications, parenteral nutrition, bowel obstruction, and flare-ups of disease. Most ALT elevations in children with IBD are transient and appear to relate to medications or disease activity. Sclerosing cholangitis was noted in 3.5% of UC patients and <1% of CD patients, while CAH was found in <1% of UC or CD patients. Unless evidence of chronic liver disease is present, the initial finding of mild to moderate ALT elevation (80-250 U/L) should prompt observation before extensive evaluation.

Atypical rectosigmoid histology in children with newly diagnosed ulcerative colitis.

BACKGROUND: In the untreated patient with inflammatory colitis, rectal sparing or patchy rectal inflammation is generally considered a sign of Crohn's disease (CD), rather than ulcerative colitis (UC). METHODS: The initial endoscopic rectosigmoid mucosal biopsies obtained at disease onset from 12 untreated children with UC who ultimately required surgery were blindly reviewed (randomly mixed with another 62 specimens obtained from children with CD or treated UC). Biopsies were classified as typical UC if there was diffuse, active inflammation and severe crypt destruction or distortion. Those with patchy, active inflammation and only mild crypt changes were classified as CD. Because all 12 subjects had ultimately been proven to have UC by examination of a subtotal colectomy specimen, for the purposes of this report biopsies read as either normal or CD were both considered evidence of atypical UC with rectal sparing. RESULTS: Five of 12 subjects (seven biopsies) had atypical histology. Mild, patchy inflammation was seen in six rectal or sigmoid biopsies, whereas one rectal biopsy was normal. The remaining seven subjects (10 biopsies) had diffuse inflammation. Two of five subjects with atypical biopsies had an endoscopically normal rectosigmoid, one had patchy inflammation, and the remaining two had diffuse endoscopic changes. All seven subjects with typical UC histology had diffuse endoscopic changes. Subjects with atypical findings could not be differentiated by age, duration, or types of symptoms at presentation, years of disease at colectomy, or indications for colectomy. CONCLUSIONS: Patchy or absent inflammation of the rectum and sigmoid can be present in untreated children with UC at disease onset. Because such children may be mistakenly diagnosed as having CD, these data must be considered when treatments or clinical research protocols are designed to include children with colitis.

The morphologic relationship of sinus and fistula formation to intestinal stenoses in children with Crohn's disease.

Sinus and fistula (SF) formation in adults with Crohn's disease has been ascribed to increased intraluminal pressure from stenotic lesions or to inflammation. We retrospectively evaluated 55 surgically resected specimens from 30 children with Crohn's disease for stenotic lesions, sinuses, fistulas, and inflammation. Eighteen of 30 children had one operation, and there were 12 multiple surgeries. Thirty-one of 55 specimens (56%) contained stenoses. SF formation was seen in 16 of 31 specimens with stenosis; it developed proximal to the stenosis in seven patients, distal in five, and both proximal and distal in four. SF formation was also noted in 12/24 specimens without stenosis. In 93% of the cases, the SF was associated with moderate to severe inflammation. Although 56% of the patients had stenoses, SF frequently developed independent of stenosis. All SF were associated with inflammation. Therefore, inflammation rather than increased intraluminal pressure appears to be the primary factor in SF formation in children with Crohn's disease.

Growth failure in pediatric inflammatory bowel disease.

To assess whether children with inflammatory bowel disease (IBD) develop permanent impairment of linear growth, we analyzed records from 48 young adults who had IBD during childhood or early adolescence (Tanner I-III; 11.8 +/- 2.4 years old at diagnosis). All were fully grown (Tanner V; 21.1 +/- 3.0 years) at last examination. Adult heights were predicted from data obtained at or shortly after the diagnosis of IBD by three methods: height for age percentile, the Bailey-Pinneau (BP), and Roche-Wainer-Thissen (RWT) methods. Predicted adult heights were then compared with the actual ultimate height of each subject. Permanent growth failure occurred in 19-35% of subjects, depending upon the method used to assess growth. Overall, 31% (15 of 48) of the subjects had deficits of adult height identified by two or more methods, including 14 of 38 (37%) of those with Crohn's disease but only one of 10 with ulcerative colitis. Age at diagnosis of IBD, age at last examination, age at cessation of linear growth, and site of IBD did not differ between impaired and normal growth groups. Duration of corticosteroid use was longer (p < 0.05) in growth-impaired subjects. In addition, although 60% of all subjects had periods of poor growth that put them in height-for-age percentiles two or more major growth channels below previous percentiles, only 19% remained at these levels upon achieving their final adult heights. Permanent impairment of linear growth leading to clinically meaningful deficits of ultimate adult height is common in patients with IBD in childhood or early adolescence. New therapeutic approaches are needed to address this problem.

Immunosuppressive therapy in pediatric inflammatory bowel disease: results of a survey of the North American Society for Pediatric Gastroenterology and Nutrition. Subcommittee on Immunosuppressive Use of the Pediatric IBD Collaborative Research Forum.

We report the results of a survey of the membership of the North American Society for Pediatric Gastroenterology and Nutrition designed to determine pediatric gastroenterologists' attitudes toward the use of immunosuppressive therapy for inflammatory bowel disease (IBD), and to assess how these medications are actually being used in the treatment of children with IBD. One hundred five physicians (27% of surveys) responded. Eighty-eight (84%) had prescribed 6-mercaptopurine and/or azathioprine for IBD, and 66 believed that they were effective. Only 12 had used cyclosporine and four methotrexate. All physicians who had used immunosuppressives in IBD had prescribed them for patients with Crohn's disease, but only 50% had prescribed them for ulcerative colitis. The predominant indications for use included intractable symptoms despite traditional medical therapy (92%) and for corticosteroid-sparing effects (86%). Potential toxicities of greatest concern included marrow and immune suppression and malignancy. The vast majority of responders were not certain what to recommend with respect to the use of immunosuppressive agents prior to and during pregnancy. A clinical database was compiled from 165 retrospective case reports submitted by 45 physicians (33 medical facilities). At the start of immunosuppressive therapy, patients were 15.3 +/- 4.0 yr of age, and 52% were Tanner IV-V. Eighty-one percent had Crohn's disease, 8% ulcerative colitis, and 11% indeterminant colitis. One hundred twenty-two were treated with 6-mercaptopurine, and 43 with azathioprine. Five also received cyclosporine concomitantly. Overall, 68% of patients treated with an immunosuppressive improved. Complications requiring discontinuation of immunosuppressive therapy occurred in 6% of patients. It appears that immunosuppressives are commonly used to treat children with IBD despite a paucity of data regarding their safety and efficacy in this age group. Controlled, prospective trials are warranted to better define the role of immunosuppressive therapy in pediatric IBD.

The appendix in inflammatory bowel disease in children.

The morphologic characteristics of the colon in ulcerative colitis and Crohn's disease are well established, but specific appendiceal pathology is less clearly defined. In addition, the frequency of appendiceal involvement in children with inflammatory bowel disease has also not been delineated. We have determined the prevalence of appendiceal involvement in 41 children with inflammatory bowel disease (24 with Crohn's disease and 17 with ulcerative colitis) who required colonic resection and have defined the histopathologic characteristics of the appendix in these diseases. All appendices were abnormal. Specific changes of Crohn's disease or ulcerative colitis were observed respectively in 50% and 56% of the appendices in our patient population. Nonspecific changes only such as fibrous obliteration, serosal fibrosis and lymphoid and/or neuronal hyperplasia were noted in the remaining appendices. The severity of ileocolonic and appendiceal inflammation was similar in about two thirds of the patients with either type of inflammatory bowel disease.

6-Mercaptopurine and spermatogenesis in the young rat.

In recent years, 6-MP treatment has been beneficial in the treatment of inflammatory bowel disease (IBD). Since 6-MP and its metabolites interfere with various steps in nucleic acid biosynthesis, chronic use of 6-MP could theoretically alter normal cell turnover, including spermatogenesis. Therefore, we have investigated the effect of daily 6-MP administration on spermatogenesis in the young rat. 6-Mercaptopurine was administered in clinically relevant doses 24 and 40 mg/m2. Testicular weights of rats treated with 24 mg/m2 for 75 days or 40 mg/m2 for 25 days were not significantly different among 6-MP, pair-fed, or ad libitum chow-fed groups. Quantitation of the stages of seminiferous tubules or the number of homogenization-resistant, mature spermatids per testis were not affected by 6-MP treatment. In addition, 6-MP had no effect on serum testosterone or on HCG-stimulated testosterone release by the testes. These results suggest that chronic low-dose 6-MP therapy, as used in the treatment of IBD, may not carry as great a risk for suppression of spermatogenesis as theorized. Our study in animals indicates that evaluation of 6-MP and spermatogenesis in man is warranted.

Hepatic pathology in pediatric acquired immunodeficiency syndrome.

In a retrospective study we assessed the hepatic changes in children with the acquired immunodeficiency syndrome by reviewing 12 biopsy specimens and 48 autopsy specimens from 54 children. Hepatopathology differed in biopsy and autopsy material. In biopsy specimens, chronic active hepatitis with predominantly T8 lymphocytes by tissue immunochemistry was common (five of 12 specimens). Fatty degeneration and hepatocellular necrosis were either absent, mild, or patchy. On the other hand, at autopsy, chronic active hepatitis was not observed. The most prominent changes were extensive fatty degeneration, nonspecific portal mononuclear infiltration, portal fibrosis, and confluent (ischemic) necrosis. Opportunistic infections such as Mycobacterium avium-intracellulare (MAI) were noted only at autopsy. In addition, three unusual morphologic characteristics were noted: nodular lymphoplasmacytic portal infiltrate, a pseudosarcomatous variant of Mycobacterium avium-intracellulare infection, and multinucleated giant cells (foreign both type and giant cell transformation of hepatocytes).