Diagnosis of intestinal tuberculosis using a monoclonal antibody to Mycobacterium tuberculosis

AIM:To investigate the utility of immunohistochemical(IHC) staining with an antibody to Mycobacterium tuberculosis(M.tuberculosis) for the diagnosis of intestinal tuberculosis(TB).METHODS:We retrospectively identified 10 patients(4 males and 6 females;mean age = 65.1 ± 13.6 years) with intestinal TB.Clinical characteristics,including age,gender,underlying disease,and symptoms were obtained.Chest radiograph and laboratory tests,including sputum Ziehl-Neelsen(ZN) staining,M.tuberculosis culture,and sputum polymerase chain reaction(PCR) for tubercle bacilli DNA,as well as Tuberculin skin test(TST) and QuantiFERON-TB gold test(QFT),were examined.Colonoscopic records recorded on the basis of Sato's classification were also reviewed,in addition to data from intestinal biopsies examined for histopathological findings,including hematoxylin and eosin staining,and ZN staining,as well as M.tuberculosis culture,and PCR for tubercle bacilli DNA.For the present study,archived formalin-fixed paraffin-embedded(FFPE) intestinal tissue samples were immunohistochemically stained using a commercially available species-specific monoclonal antibody to the 38-kDa antigen of the M.tuberculosis complex.These sections were also stained with the pan-macrophage marker CD68 antibody.RESULTS:From the clinical data,we found that no patients were immunocompromised,and that the main symptoms were diarrhea and weight loss.Three patients displayed active pulmonary TB,six patients(60%) had a positive TST,and 4 patients(40%) had a positive QFT.Colonoscopic findings revealed that all patients had type 1 findings(linear ulcers in a circumferential arrangement or linear ulcers arranged circumferentially with mucosa showing multiple nodules),all of which were located in the right hemicolon and/or terminal ileum.Seven patients(70%) had concomitant healed lesions in the ileocecal area.No acid-fast bacilli were detected with ZN staining of the intestinal tissue samples,and both M.tuberculosis culture and PCR for tubercle bacilli DNA were negative in all samples.The histopathological data revealed that tuberculous granulomas were present in 4 cases(40%).IHC staining in archived FFPE samples with anti-M.tuberculosis monoclonal antibody revealed positive findings in 4 patients(40%);the same patients in which granulomas were detected by hematoxylin and eosin staining.M.tuberculosis antigens were found to be mostly intracellular,granular in pattern,and primarily located in the CD68 + macrophages of the granulomas.CONCLUSION:IHC staining with a monoclonal antibody to M.tuberculosis may be an efficient and simple diagnostic tool in addition to classic examination methods for the diagnosis of intestinal TB.

Endoscopic and radiographic features of gastrointestinal involvement in vasculitis

Vasculitis is an inflammation of vessel walls,followed by alteration of the blood flow and damage to the dependent organ.Vasculitis can cause local or diffuse pathologic changes in the gastrointestinal (GI) tract.The variety of GI lesions includes ulcer,submucosal edema,hemorrhage,paralytic ileus,mesenteric ischemia,bowel obstruction,and life-threatening perforation.The endoscopic and radiographic features of GI involvement in vasculitisare reviewed with the emphasis on small-vessel vasculitis by presenting our typicalcases,including Churg-Strauss syndrome,HenochSch nlein purpura,systemic lupus erythematosus,and Beh et's disease.Important endoscopic features are ischemic enterocolitis and ulcer.Characteristic computed tomographic findings include bowel wall thickening with the target sign and engorgement of mesenteric vessels with comb sign.Knowledge of endoscopic and radiographic GI manifestations can help make an early diagnosis and establish treatment strategy.

Endoscopic and histopathological study on the duodenum of Strongyloides stercoralis hyperinfection

AIM:To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis(S.stercoralis)hyperinfection. METHODS:Over a period of 23 years(1984-2006),we investigated 25 patients withS.stercoralis hyperinfection who had had an esophagogastroduodenoscopy before undergoing treatment for strongyloidiasis.The clinical and endoscopic findings were analyzed retrospectively. RESULTS:Twenty-four(96%)of the patients investigated were under immunocompromised condition which was mainly due to a human T lymphotropic virus type 1(HTLV-1)infection.The abnormal endoscopic findings,mainly edematous mucosa,white villi and erythematous mucosa,were observed in 23(92%) patients.The degree of duodenitis including villous atrophy/destruction and inflammatory cell infiltration corresponded to the severity of the endoscopic findings. The histopathologic yield for identifying larvae was 71.4% by duodenal biopsy.The endoscopic findings of duodenitis were more severe in patients whose biopsies were positive for larvae than those whose biopsies were negative(Endoscopic severity score:4.86±2.47vs 2.71 ±1.38,P<0.05). CONCLUSION:Our study clearly demonstrates that,in addition to stool analysis,endoscopic observation and biopsies are very important.We also emphasize that S.stercoralis and HTLV-1 infections should be ruled out before immunosuppressive therapy is administered in endemic regions.

An autopsy case of a primary aortoenteric fistula: A pitfall of the endoscopic diagnosis

A primary aortoenteric fistula (PAEF), defined as a communication between the native aorta and the gastrointestinal tract, is a rare cause of gastrointes-tinal bleeding. The preoperative diagnosis of PAEF is extremely difficult. Consequently, PAEF may cause sudden and unexpected death. We present an autopsy case of a 68-year-old man who died of massive gastro-intestinal bleeding due to a PAEF. Autopsy revealed a pinhole rupture located on the third part of the duode-nal mucosa and fistulized into the adjacent abdominal aortic aneurysm (AAA). Our case indicates that the aortoenteric fistula can result in fatal gastrointestinal bleeding. Consequently, a PAEF should be included in the differential diagnosis of gastrointestinal bleeding.