Expression of bcl-2 in enteric neurons in normal human bowel and Hirschsprung disease

Diagnostic utility of Bcl-2 immunohistochemical expression in pediatric functional bowel obstruction cases with ganglionated specimens

Background

Functional disturbances of the gastrointestinal tract are caused by a number of neurodysplastic conditions, including diseases that are rarer than Hirschsprung’s disease (HSCR), such as ganglion cell immaturity and intestinal neuronal dysplasia (IND). Bcl-2 shows positive immunoreactivity in degenerative and immature ganglion cells (IGCs). This work evaluates the implication of the immunohistochemical expression of Bcl-2 in cases of pediatric intestinal pseudo-obstruction (IPO) with ganglionated specimens.

This 2-year prospective observational study was conducted from January 2017 to December 2019 on all intestinal specimens for cases referred from a pediatric surgery department with clinical data suggesting IPO (abdominal distension > 3 months, intermittent bilious vomiting, no radiological evidence of the transitional zone of HSCR or evidence of mechanical obstruction). The exclusion criteria were patients with IPO related to myopathic disorders, aganglionic biopsies, and specimens with inadequate tissue blocks. The same number of intestinal specimens of cases without IPO was used as a control group. All specimens underwent a histologic examination of ganglion cells and nerve bundles and were also evaluated for Bcl-2 immunohistochemical expression.

Results

Twenty-one specimens were analyzed, including six colonic resection specimens and 15 intestinal biopsies taken by full-thickness transanal biopsy (n = 12) or incisional biopsy from inadequately functioning stomas (n = 3). The mean ± standard deviation age of the patient cohort was 22 ± 7.4 months (range, 19–153 months), and there were 13 (61.9%) male patients. Bcl-2 protein was strongly positive in 57.1% of the cases, weakly positive in 19%, and negative in 23.8% as well as in all 21 control specimens. A highly significant correlation was observed between Bcl-2 expression and ganglion cell number (P < 0.001), where all hyperganglionic specimens showed strong positivity compared with the hypoganglionic and adequately ganglionic specimens. A positive association was also found between Bcl-2 expression and IND compared with other disorders of dysganglionosis (P = 0.04) and post-HSCR cases (P = 0.002).

Conclusion

Bcl-2 immunohistochemistry is a valuable tool to diagnose allied disorders of HSCR through its expression in IGCs, which are difficult to identify by conventional hematoxylin and eosin staining.

Pathophysiology of Hyperechogenic Bowel in Congenitally Human Cytomegalovirus Infected Fetuses

Hyperechogenic bowel (HB) is a nonspecific ultrasound finding that can be associated with human cytomegalovirus (CMV) congenital infection. In this study, we investigated HB pathophysiology in CMV-infected fetuses. We examined small and large intestine as well as pancreas in 8 fetuses at 22 weeks of gestation with congenital CMV infection. Ultrasound findings showed 4 fetuses with HB and 4 without. As negative group, 4 fetuses without CMV infection and without HB were studied. Immunohistochemistry for CMV, lymphocytic infiltrate, B-cell leukemia/lymphoma-2 (bcl-2), CD-117, cystic fibrosis transmembrane regulator (CFTR) were performed. HB fetuses showed multiple and sequential CMV-positive ganglion cells of Auerbach’s myenteric plexus. In the ganglia, bcl-2 was weakly expressed representing a reduced neuronal functionality. CD-117 revealed a regular distribution of Cajal cells, the pacemakers of intestinal contractility. Pancreas showed normal CFTR staining, indicating a preserved exocrine secretion, thus unlikely a contributory factor in HB. In CMV-infected fetuses without HB, CMV-positive cells were scatteredly found in ganglion cells and bcl-2 was strongly expressed. Intestinal CD-117 and pancreatic CFTR expression were similar to fetuses with HB. In conclusion, fetal CMV infection of the bowel may lead to peristalsis impairment (paralytic ileus) due to intestinal plexus involvement, which at ultrasound appeared as HB.

Investigation of the expression of apoptosis-inducing factor-mediated apoptosis in Hirschsprung's disease

One of the widely accepted hypotheses of Hirschsprung's disease (HD) is that the absence of ganglion cells in the distal part of the intestine is caused by the death of enteric neural crest-derived cells following migration. Although a caspase-dependent pathway has not yet been detected in the HD bowel, it is unclear whether a caspase-independent pathway contributes toward aganglionosis. In the current study, we observed highly condensed marginal heterochromatin in nuclei only in the transitional segment using electron microscopy and a high proportion of TUNEL-positive cells were observed in the transitional segment. Activation of caspase was not observed in any segments of the HD bowel upon characterization of the apoptotic pathway. Rather, real-time PCR results showed that apoptosis-inducing factor (AIF) and calpain-1 mRNAs were highly expressed in the transitional segment, whereas autophagy protein 5 (Atg5) was highly expressed in the narrow segment. Western blot results were consistent with mRNA levels, with increased AIF, calpain-1, and Atg5 expressions in the transitional segment compared with the dilated segment. Furthermore, correlation analysis indicated an inverse correlation between calpain-1 and Atg5 mRNA levels in both the narrow segment and the transitional segment. These results indicated that apoptosis occurs in the HD bowel. The detection of related genes indicates that the AIF-mediated apoptotic pathway may be responsible for the absence of ganglion cells in HD and calpain-1 may act as the regulatory switch between autophagy and apoptosis.

Modified Rapid AChE Method (MRAM) for Hirschsprung Disease Diagnosis: A Journey from Meier-Ruge Until Now

Hirschsprung disease (HSCR) can be diagnosed using a variety of histological and immunohistochemical methods and stains. Because of the nature of the condition and the need for a rapid diagnostic confirmation, those methods with high accuracy and fast turnaround times are preferred. The authors of this paper have used rapid acetylcholinesterase (AChE) immunohistochemistry in conjunction with standard H&E in order to optimize diagnostic accuracy, and present a modified rapid AChE method (MRAM) that has been successfully utilized for over 20 years. The authors also present a list of over 30 different methods and stains that have been proposed for Hirschsprung disease diagnosis.

Diagnostic accuracy of radiologic scoring system for evaluation of suspicious hirschsprung disease in children

BACKGROUND

In 1996, Donovan and colleagues represented a scoring system for better prediction of Hirschsprung disease (HD).

OBJECTIVES

Our objective was to devise another scoring system that uses a checklist of radiologic and clinical signs to determine the probability of HD in suspicious patients.

PATIENTS AND METHODS

In a diagnostic accuracy study, 55 children with clinical manifestations of HD that referred to a training hospital from 1998 to 2011 were assessed. A checklist was used to evaluate the items proposed by contrast enema (CE), based on six subscales, including transitional zone, rectosigmoid index (RSI), irregular contractions in aganglionic region, cobblestone appearance, filling defect due to fecaloid materials and lack of meconium defecation during the first 48 hours after birth. The patients were classified as high score and low score. Sensitivity, specificity, positive predictive value and negative predictive value of our scoring system were calculated for identifying HD, in comparison with pathologically proved or ruled out HD.

RESULTS

Of the 55 patients, 36 (65.4%) cases had HD and 19 (34.6%) cases were without HD. In the HD group, 32 patients showed high scores and four patients had low scores. The sensitivity and specificity of our diagnostic scoring system were 88.9% (95% CI: 78.6% - 99.1%) and 84.2% (95% CI: 68.7% - 100%), respectively. Moreover, positive predictive value (PPV) and negative predictive value (NPV) were 91.4% (95% CI: 82.1% - 100%) and 80% (95% CI: 62.5% - 97.5%), respectively.

CONCLUSIONS

Our new scoring system of CE is a useful diagnostic method in HD. If a patient's score is high, that patient is highly suspicious to HD and reversely, when one's score is low, the patient presents a reduced probability to be diagnosed with HD.

Value of calretinin immunostaining in diagnostic pathology: a review and update

Calretinin is a member of the EF-hand family of calcium-binding proteins. Because its expression is highly restricted to mesotheliomas, calretinin is, at present, the most commonly used positive mesothelioma marker that is most often recommended to be included in the various immunohistochemical panels used to assist in the differential diagnosis of these tumors. Calretinin expression has also been reported to be commonly expressed in a wide variety of other neoplasms, including sex cord-stromal tumors, adrenal cortical neoplasms, olfactory neuroblastomas, Schwann cell tumors, cardiac myxomas, and ameloblastomas. This article reviews the information that is currently available on calretinin expression in tumors and on its application as an immunohistochemical marker in diagnostic pathology.

Utilization of peripherin and S-100 immunohistochemistry in the diagnosis of Hirschsprung disease

Evaluation of rectal biopsies for ganglion cells is performed for patients suspected of having Hirschsprung disease. At times, identification of ganglion cells can be difficult, especially in newborns. To assist in diagnosis, frozen tissue can be collected for acetylcholinesterase histochemical staining. At our institution, we developed a protocol using peripherin and S-100 immunostaining as an adjunct to hematoxylin and eosin (H&E) for the identification of ganglion cells. Further, at the time of frozen section, we performed Diff Quik staining to highlight ganglion cells. One hundred and thirty eight rectal biopsies submitted for evaluation of Hirschsprung disease were compiled from the archives of the Medical College of Georgia from 2002 to 2009. Initial evaluation consisted of eight levels of H&E-stained slides and two unstained slides each for immunostaining with peripherin and S-100. If on initial evaluation, ganglion cells were not identified, additional H&E and peripherin immunostains were performed. Peripherin immunostaining was unequivocally identified in the cytoplasm of ganglion cells of patients at all ages. Of the 136 patients with diagnostic biopsies, 80% had ganglion cells. Of these, 93% of cases were diagnosed on the original eight levels. Twenty-seven cases were devoid of ganglion cells, and of these, 81% showed submucosal neural hypertrophy on S-100 staining. Twenty-six patients had confirmed aganglionic segments at the time of colonic resection. One patient had colostomy only. A total of 54 frozen sections were performed on 25 patients over this same period of time. Diff Quick staining was found to be very useful. In this study, our protocol proved to be very sensitive, specific, and efficient for the diagnosis of Hirschsprung disease.

Apoptotic phenomena are not a major cause of enteric neuronal loss in constipated patients with dementia

Chronic constipation is a frequent symptom in patients with dementia, especially in those institutionalized. However, few data are available on the neuropathological aspects of the colon in such patients. We investigated the enteric neuropathology of the colon in two patients with longstanding dementia and intractable constipation, requiring surgery to alleviate symptoms. The results were compared to those obtained in 10 controls. No abnormalities were found at conventional histological examination, except for the presence of melanosis coli. Immunohistochemical evaluation revealed no important difference between patients and controls, except for a decreased number of enteric neurons in patients. However, this neuronal decrease was not associated to apoptotic phenomena, as observed in patients with severe idiopathic constipation. We concluded that in severely constipated patients with dementia the neuropathological abnormalities might be reconducted to a physiological neuronal decrease as a result of aging, and that the pathophysiological aspects of constipation in these subjects differ from those found in idiopathic constipation.

Colonic neuropathological aspects in patients with intractable constipation due to obstructed defecation

One of the most frequent subtypes of constipation is represented by obstructed defecation, and it has recently been reported that these patients may have colonic motor abnormalities in addition to alterations of the anorectal area. However, it is unknown whether these patients display abnormalities of the enteric nervous system, as reported in other groups of constipated subjects. For this reason, we evaluated the neuropathologic aspects of the enteric nervous system in a homogeneous group of patients with obstructed defecation. Colonic specimens from 11 patients (nine women, age range 39-66 years) undergoing surgery for symptoms refractory to any therapeutic measure, including biofeedback training, were obtained and examined by means of conventional histological methods and immunohistochemistry (NSE, S100, c-Kit, formamide-mAb, Bcl-2, CD34, alfa-actin). Analysis of the specimens showed that the enteric neurons were significantly decreased only in the submucosal plexus of patients (P<0.0001 vs controls), whereas the enteric glial cells of constipated patients were reduced in both the myenteric (P=0.018 vs controls) and the submucosal plexus (P=0.004 vs controls). No difference between patients and controls were found concerning c-Kit and CD34 expression, and the number of apoptotic neurons. These findings support the concept that at least a subgroup of patients with obstructed defecation and severe, intractable symptoms display abnormalities of the enteric nervous system, mostly related to the enteric glial cells. These findings might explain some of the pathophysiological abnormalities, and help to better understand this condition.

Enteric neuropathology of the terminal ileum in patients with intractable slow-transit constipation

Slow-transit constipation is usually considered a colonic motor disorder. However, there is some evidence that abnormalities may be present in locations other than the colon. In particular, several studies have reported abnormal motor activity of the small bowel in these patients. We evaluated the neuropathological aspects of the terminal ileum in patients with slow-transit constipation to see whether abnormalities are present that may explain an abnormal motility of the small intestine. Specimens of the terminal ileum were obtained from 16 female patients (age range, 42-76 years) with slow-transit constipation undergoing surgery for intractable symptoms. Fifteen age- and sex-matched controls were used for comparison. Histologic and immunohistochemical evaluation of the myenteric plexus and the smooth muscle of the proximal ileal resection margin was carried out by means of hematoxylin and eosin, trichrome and periodic acid-Schiff stain, neuron-specific enolase, S-100, CD117, CD34, anti-alpha-actin, desmin, and vimentin antibodies. The patient group displayed a significantly reduced number of glial cells, compared with controls, in both the submucosal and the myenteric plexus. Only 1 of the 3 populations of interstitial cells of Cajal (that associated with the deep muscular plexus) was decreased in patients. No differences were found between patients and controls concerning ganglia neurons, fibroblast-like cells, enteric neurons, apoptotic phenomena, and smooth muscle. Patients with slow-transit constipation display neuropathological abnormalities of the terminal ileum to a lesser extent than those we previously found in the colon, which might explain the abnormal motor aspects sometimes found in these patients.

The role of glial cells and apoptosis of enteric neurones in the neuropathology of intractable slow transit constipation

BACKGROUND

Idiopathic slow transit constipation is one of the most severe and often intractable forms of constipation. As motor abnormalities are thought to play an important pathogenetic role, studies have been performed on the colonic neuroenteric system, which rules the motor aspects of the viscus.

AIMS

We hypothesised that important neuropathological abnormalities of the large bowel are present, that these are not confined to the interstitial cells of Cajal and ganglion cells, and that the previously described reduction of enteric neurones, if confirmed, might be related to an increase in programmed cell death (apoptosis).

PATIENTS AND METHODS

Surgical specimens from 26 severely constipated patients were assessed by conventional and immunohistochemical methods. Specific staining for enteric neurones, glial cells, interstitial cells of Cajal, and fibroblast-like cells associated with the latter were used. In addition, gangliar cell apoptosis was evaluated by means of indirect and direct techniques. Data from patients were compared with those obtained in 10 controls.

RESULTS

Severely constipated patients displayed a significant decrease in enteric gangliar cells, glial cells, and interstitial cells of Cajal. Fibroblast-like cells associated with the latter did not differ significantly between patients and controls. Patients had significantly more apoptotic enteric neurones than controls.

CONCLUSION

Severely constipated patients have important neuroenteric abnormalities, not confined to gangliar cells and interstitial cells of Cajal. The reduction of enteric neurones may in part be due to increased apoptotic phenomena.