Immunohistochemistry and real-time Polymerase Chain Reaction: importance in the diagnosis of intestinal tuberculosis in a Peruvian population.

INTRODUCTION: The diagnosis of intestinal tuberculosis is challenging even nowadays. This study aims to report the positivity rates of new diagnostic methods such as immunohistochemistry and Real-Time Polymerase Chain Reaction in patients with intestinal tuberculosis, as well as describe the pathological and endoscopic features of intestinal tuberculosis in our population. METHODS: This was a retrospective observational study conducted in patients diagnosed with intestinal tuberculosis, between 2010 to 2023 from the Hospital Nacional Daniel Alcides Carrion and a Private Pathology Center, both located in Peru. Clinical data was obtained, histologic features were independently re-evaluated by three pathologists; and immunohistochemistry and real-time Polymerase Chain Reaction evaluation were performed. The 33 patients with intestinal tuberculosis who fulfilled the inclusion criteria were recruited. RESULTS: Immunohistochemistry was positive in 90.9% of cases, while real-time Polymerase Chain Reaction was positive in 38.7%. The ileocecal region was the most affected area (33.3%), and the most frequent endoscopic appearance was an ulcer (63.6%). Most of the granulomas were composed solely of epithelioid histiocytes (75.8%). Crypt architectural disarray was the second most frequent histologic finding (78.8%) after granulomas, but most of them were mild. CONCLUSION: Since immunohistochemistry does not require an intact cell wall, it demonstrates higher sensitivity compared to Ziehl-Neelsen staining. Therefore, it could be helpful for the diagnosis of paucibacillary tuberculosis.

[Duodenal obstruction and upper gastrointestinal bleeding as the initial presentation of an isolated duodenal tuberculosis]. / Obstrucción duodenal y hemorragia digestiva alta como presentación inicial de una tuberculosis duodenal aislada.

Primary duodenal tuberculosis is rare, even in endemic regions. The diagnosis poses a major challenge and requires a high index of suspicion, supported by imaging studies, microbiology, and histopatology obtained by endoscopic or surgical biopsy. We report the case of a 31-year-old man, without HIV infection or any previous history of tuberculosis, who presented with duodenal obstruction. After exploratory laparotomy, he presented a duodenal stenosis and upper gastrointestinal bleeding. A total of four diagnostic procedures (one laparotomy and three endoscopies) were performed, all of which included biopsies. Only the last endoscopy made with the technique "biopsy upon biopsy" showed the presence of acid fast bacilli and granulomas. The diagnosis of tuberculosis was confirmed by polymerase chain reaction in duodenal tissue. There was no evidence of involvement of other organs by tuberculosis. The patient had an excellent therapeutic response.

Obstrucción duodenal y hemorragia digestiva alta como presentación inicial de una tuberculosis duodenal aislada / Duodenal obstruction and upper gastrointestinal bleeding as the initial presentation of an isolated duodenal tuberculosis

Resumen La tuberculosis duodenal primaria es muy infrecuente, incluso en regiones endémicas. El diagnóstico plantea un gran reto, y requiere un alto índice de sospecha, apoyado en estudios de imágenes, microbiología, e histopatología obtenida por biopsia endoscópica o quirúrgica. Presentamos el caso de un varón de 31 años, sin infección por VIH ni antecedente de tuberculosis, que debutó con una obstrucción duodenal. Posterior a una laparatomía exploradora presentó una estenosis duodenal y una hemorragia digestiva alta. Luego de varias biopsias no concluyentes, sólo la última, realizada con la técnica "biopsia sobre biopsia", demostró la presencia de granulomas con bacilos ácido-alcohol resistentes. El diagnóstico de tuberculosis fue confirmado por reacción de polimerasa en cadena de tejido duodenal. No se evidenció compromiso de otros órganos. La respuesta terapéutica fue excelente.

Primary duodenal tuberculosis is rare, even in endemic regions. The diagnosis poses a major challenge and requires a high index of suspicion, supported by imaging studies, microbiology, and histopatology obtained by endoscopic or surgical biopsy. We report the case of a 31-year-old man, without HIV infection or any previous history of tuberculosis, who presented with duodenal obstruction. After exploratory laparotomy, he presented a duodenal stenosis and upper gastrointestinal bleeding. A total of four diagnostic procedures (one laparotomy and three endoscopies) were performed, all of which included biopsies. Only the last endoscopy made with the technique "biopsy upon biopsy" showed the presence of acid fast bacilli and granulomas. The diagnosis of tuberculosis was confirmed by polymerase chain reaction in duodenal tissue. There was no evidence of involvement of other organs by tuberculosis. The patient had an excellent therapeutic response.

Severe hypercholesterolemia mediated by lipoprotein X in a patient with cholestasis.

Lipoprotein X (LpX) is an abnormal lipoprotein associated with cholestasis. It is a significant cause of severe hypercholesterolemia and should always be considered in patients with cholestatic liver disease. This case highlights the significance of LpX as a cause of severe hypercholesterolemia in a patient with cholestasis secondary to a granulomatous hepatitis attributed to tuberculosis. Lipoprotein agarose gel electrophoresis and gradient gel electrophoresis were performed for the detection of LpX. The liver function tests, electrolytes, lipid profile and bile acids were also determined. Anti-tuberculous therapy was initiated and the liver functions improved with normalisation of the lipid profile.

A 33-year-old Haitian immigrant with 7 months of abdominal pain and progressive distension.

We report a case of a 33-year-old previously healthy Haitian immigrant with a 7-month history of abdominal pain, fever and ascites. He had a history of positive tuberculin skin test but never underwent treatment for latent tuberculosis (TB) infection. Initial examination showed abdominal distension. Abdominal CT scan showed mild ascites, abnormal soft tissue in the greater omentum and small bowel mesentery, retroperitoneal adenopathy, peritoneal thickening and dilated loops of small bowel. Paracentesis and thoracentesis were initially non-diagnostic. HIV testing was negative. The differential diagnosis included lymphoma and TB peritonitis. The omental mass was biopsied under ultrasound guidance, and histopathology revealed non-necrotising granulomas. Sputum cultures and omental biopsy cultures subsequently grew Mycobacterium tuberculosis, and a diagnosis was made of pulmonary TB with TB peritonitis. The patient responded well to the initiation of anti-TB treatment.

Simultaneous cytomegalovirus and Mycobacterium tuberculosis infection presenting as hemorrhagic colitis 3 years after a kidney transplant.

Cytomegalovirus is an important cause of colonic disease in solid organ transplant recipients. Although several reports have shown that simultaneous infection with other pathogens may aggravate the course of cytomegalovirus colitis, to our knowledge, no case of colitis caused by simultaneous cytomegalovirus and Mycobacterium tuberculosis has been previously reported. We describe a case of hemorrhagic colitis associated with simultaneous cytomegalovirus/ Mycobacterium tuberculosis infection in a 26-year-old woman, 38 months after a kidney transplant. Initial results of histopathologic analyses of gastrointestinal biopsies showed that tuberculosis was the only cause of colitis, as no morphologic alteration suggestive of cytomegalovirus infection was observed on hematoxylin-eosin staining. However, further analysis with immunoperoxidase staining confirmed the clinical suspicion of cytomegalovirus infection. This report shows that cytomegalovirus/tuberculosis coinfection may be a cause of late-onset colitis among solid organ transplant recipients. It also illustrates that coinfection with other pathogens may pose an additional challenge for diagnosing gastrointestinal cytomegalovirus disease.

Tuberculosis intestinal / Intestinal tuberculosis

La tuberculosis (TBC) es una enfermedad infecciosa crónica, de tipo granulomatosa, producida por el Mycobacterium tuberculosis. En Chile es endémica, con tasas de 18 casos por 100.000 habitantes. La forma extrapulmonar constituye el 24 por ciento de los casos totales, siendo el compromiso intestinal uno de los más frecuentes, destacando la región ileo-cecal como la más afectada (90 por ciento de los casos). El diagnóstico es complejo ya que las manifestaciones clínicas son inespecíficas y el bacilo difícil de aislar, lo que muchas veces retrasa el inicio del tratamiento aumentando la morbimortalidad. Las manifestaciones clínicas habituales son: dolor abdominal, fiebre, baja de peso y compromiso ileal, siendo frecuente la duda diagnóstica con otras enfermedades que afectan el íleon distal, principalmente la enfermedad de Crohn. El diagnóstico definitivo sólo puede ser realizado a través de la histología o la detección directa del bacilo. La notificación de los casos de TBC es obligatoria en nuestro país; el tratamiento estándar con drogas antituberculosas es altamente efectivo y está garantizado para toda la población chilena.

Tuberculosis (TBC) is a chronic infectious disease of granulomatous type, caused by Mycobacterium tuberculosis. In Chile, the disease is endemic with rates of 18 cases per 100,000 inhabitants. The extrapulmonary form accounts for 24 percent of the total cases. Of these, intestinal tuberculosis is the most frequent, being the ileo-colonic region the most affected (90 percent of cases). Diagnosis is complex because the clinical manifestations are non specific and the bacteria is difficult to isolate, which often delays the onset of treatment thus increasing morbidity and mortality. The most common clinical manifestations are abdominal pain, fever, weight loss and ileal disease, increasing the diagnostic uncertainty in relation to other diseases affecting the distal ileum, mainly Crohn’s disease. A definitive diagnosis can only be made through histology or direct detection of the bacillus. Notification of TBC cases is mandatory in our country; standard treatment with antituberculosis drugs is highly effective and is guaranteed for the entire Chilean population.