Clinical profile of 103 patients with abdominal tuberculosis in Nepal

Background and aims: The nonspecific clinical features of abdominal tuberculosis (TB) have made its diagnosis difficult, which can lead to the poor outcome in patients who are not able to receive early treatment. Hence, the aim of our study was to determine the clinical profile of abdominal TB in the patients of Nepal. Methods: This is a prospective observational study in which 103 patients with abdominal TB were analyzed for clinical profiles from May 2010 to April 2015. All diagnosed patients received anti-tubercular treatment (ATT) and were followed up at 1 and 6 months of ATT. Results: Among 103 patients of abdominal TB [males 48 (46.6%), females 55 (53.4%); mean age 33.1 years (±12.9)], 47.6% had histopathological examination (HPE) confirmation, 27.2% had high ascitic adenosine deaminase (ADA) value and another 25.2% had suggestive imaging findings. The common symptoms were abdominal pain (84.5%), weight loss (75.7%), anorexia (63.1%), chronic diarrhea (56.3%) and fever (52.4%). The mean weight was <50 Kg, hemoglobin <11 gm/dl and Erythrocyte Sedimentation Rate >40 mm/first hour. The sites involved were ileo-cecal (35.9%), peritoneal (27.2%), ileal (15.5%), colonic (15.5%), lymph nodal (3.9%) and gastroduodenal (1.9%). The sensitivity of HPE for diagnosis of abdominal TB was 47.6% (95% confidence interval 37.6% to 57.6%). All patients of abdominal TB had a good clinical response after ATT. Conclusion: The common symptoms of abdominal TB were abdominal pain, weight loss, anorexia, chronic diarrhea and fever. Since the diagnosis of abdominal TB by HPE may not always be positive, other parameters such as ascitic ADA value, imaging findings and associated supportive clinical features have to be considered, and a therapeutic trial of ATT may be indicated so that all patients of abdominal TB can be treated early in the course of disease. DOI Name http://dx.doi.org/10.3126/jaim.v4i2.16896


INTRODUCTION
Apart from the commonly occurring pulmonary tuberculosis (TB), the extra-pulmonary tuberculosis (EPTB) is also becoming a common cause of morbidity and mortality in a developing country like Nepal. The EPTB involves 11-16% of all patients of tuberculosis out of which 3 to 4% belong to abdominal TB. 1 Primary gastrointestinal TB can occur as a result of ingestion of milk or food infected with Mycobacterium bovis, but it is rare nowadays. 2 Infection with Mycobacterium tuberculosis causing abdominal TB can occur usually by swallowing of the infected sputum in active pulmonary TB, by hematogenous dissemination from a focus of active pulmonary TB or miliary TB, by lymphatic spread from infected mesenteric lymph nodes and by direct spreading from infected adjacent organs. 3 The sites of Involvement in abdominal TB include gastrointestinal tract, peritoneum, lymph nodes and solid organs such as liver, spleen and pancreas. 3 About 70-78% of abdominal TB is caused by gastrointestinal TB, with ileocecal area being the most commonly involved site. 4 The characteristic lesions produced in intestinal TB include ulcerative, hypertrophic, stricturous or constrictive and a combination of these forms such as ulcero-constrictive or ulcero-hypertrophic. 2 Strictures are usually formed due to the cicatrical healing of ulcerative intestinal lesions. Peritoneal involvement occurs in 4-10% of EPTB and is caused by direct spread of TB from ruptured lymph nodes and intra-abdominal organs or hematogenous seeding. 4 Peritoneal involvement may occur in the form of ascites or peritoneal adhesions; the mesenteric or retro-peritoneal lymph nodes are the main nodes involved in abdominal TB. Tubercular Infection often results in granuloma formation, caseation, mucosal ulceration, fibrosis, and scarring. [4][5][6][7] Abdominal TB is a great mimic because of its varied clinical features and has been considered in a differential diagnosis of pyrexia of unknown origin, 8 unexplained weight loss, 9 and unexplained and chronic abdominal symptoms, 10 hepatosplenomegaly, 11 Crohn's disease, 12 or gastrointestinal malignancy. 13 The nonspecific clinical features have made the diagnosis of abdominal TB difficult. High index of suspicion is required to make a diagnosis of abdominal TB; otherwise, delayed diagnosis or misdiagnosis is likely to happen, which can lead to the poor outcome in patients who are not able to receive early treatment. There has been a few studies about the abdominal TB done in Nepal till date. 14,15 Hence, the aim of our study is to determine the clinical profile of abdominal TB in the patients of Nepal.

METHODS:
This is a prospective observational study in which a total of Isoniazid, Pyrazinamide and Ethambutol and the next four months with Rifampicin and Isoniazid. 16 The patients were followed up after 1 month and 6 months to assess for the response.
Among a group of patients, whom HPE was not conclusive and ascitic ADA was not high, but a therapeutic trial of antitubercular treatment (ATT) was given, 23 patients did not do better with ATT on follow up of 1 month and was excluded from the study. Finally, 103 patients were labelled as having abdominal TB and were available for the analysis of the study.
All of 103 patients were followed up after 6 months with a repeat colonoscopy and or UGI endoscopy to document the healing of the prior lesion.
The informed consent was taken from all patients and the study protocol was approved from the ethics committee of the participating centers.
The clinical features studied were pain abdomen, weight loss, anorexia, chronic diarrhea, fever, bloating, anemia, nausea, vomiting, bleeding per rectum, past history of TB, family history of TB, jaundice, lymphadenopathy, edema, clubbing, pulse, systolic blood pressure, diastolic blood pressure and weight.
The laboratory investigations included were sputum for Acid Fast Bacillus (AFB) staining, hemoglobin, white blood cell (WBC) total count and differential count, erythrocyte sedimentation rate (ESR) and other relevant parameters. The imaging study was done with chest X-ray, ultrasonogaphy and contrast enhanced computerized tomography scan of abdomen and pelvis in relevant patients. The location of disease was noted as ileal, ileo-cecal, colonic, ileocecal, colonic, gastroduodenal, peritoneal and lymph nodal. In the patients with ascites, the sample of ascitic fluid was assessed for Adenosine Deaminase (ADA), AFB staining and other parameters. The ascitic ADA level of > 33 U/L was considered as suggestive of tubercular ascites. 17 During the endoscopic procedure, the morphological characteristics of the lesion were defined as ulceration, nodule, deformed ileo-cecal valve, mass and stricture.
The data were entered daily in a personal computer prospectively. The distribution of abdominal TB was recorded      The endoscopic morphological characteristics of the intestinal tubercular lesion were ulcerative, nodular, stricture, mass, or combination of ulcerative-nodular lesion with or without stricture, or deformed ileo-cecal valve, which got healed completely after a course of ATT. (Figure 2 and 3).

DISCUSSION
Our study showed that the common symptoms of abdominal TB were abdominal pain, weight loss, anorexia, chronic diarrhea and fever, which were comparable to the other studies done previously and is shown in Table 6.