Abdominal tuberculosis in southeastern Taiwan: 20 years of experience

Abdominal Tuberculosis: Experience from Two Tertiary-Care Hospitals in the Paris Region

Abdominal tuberculosis (ATB) is uncommon and not very well known by clinicians. We describe the characteristics, evolution, and treatment of patients with ATB in two large hospitals in the Paris region. We reviewed all records of patients treated for ATB, from January 01, 2010 to December 01, 2016, diagnosed by bacteriological and/or histological methods or highly suspected because of clinical/radiological features. We included 80 patients, with a median (IQR) age of 39 (29-50) years, with 56.2% being males. Among them, 63.7% had African origins, 15% Asian, and 11.2% European. Twenty-nine had a cause of immunosuppression (n = 21 HIV infection). The main abdominal localizations were lymph nodes (72.5%), peritoneum (62.5%), and solid organs (25%). Extra-abdominal localizations were recorded in 65 (81.2%) patients. Tuberculosis was proven bacteriologically in 71%, histologically in 50%, and solely clinical/radiological in 10% of cases. Patients received standard therapy for a median duration of 9 months, with a favorable outcome. Corticosteroid therapy was used in 15 cases, either for paradoxical reaction or to prevent complications. Abdominal TB was mainly represented by lymphatic and peritoneal localizations, proven bacteriologically, and associated with extra-abdominal localizations in most cases. The use of steroids remains controversial, but it does not seem systematically needed in case of abdominal involvement.

Utility of circulating cell-free Mycobacterium tuberculosis DNA for the improved diagnosis of abdominal tuberculosis

Abdominal tuberculosis (ATB) continues to pose a major diagnostic challenge for clinicians due to its nonspecific clinical presentation, variable anatomical location and lack of sensitive diagnostic tools. In spite of the development of several assays till date; no single test has proved to be adequate for ATB diagnosis. In this study, we for the first time report the detection of circulating cell-free Mycobacterium tuberculosis (M. tuberculosis) DNA (cfMTB-DNA) in ascitic fluid (AF) samples and its utility in ATB diagnosis. Sixty-five AF samples were included in the study and processed for liquid culture, cytological, biochemical and molecular assays. A composite reference standard (CRS) was formulated to categorize the patients into 'Definite ATB' (M. tuberculosis culture positive, n = 2), 'Probable ATB' (n = 16), 'Possible ATB' (n = 13) and 'Non-TB' category (n = 34). Two molecular assays were performed, namely, the novel cfMTB-DNA qPCR assay targeting M. tuberculosis devR gene and Xpert MTB/RIF assay (Xpert), and their diagnostic accuracy was assessed using CRS as reference standard. Clinical features such as fever, loss of weight, abdominal distension and positive Mantoux were found to be strongly associated with ATB disease (p<0.05). cfMTB-DNA qPCR had a sensitivity of 66.7% (95% CI:40.9,86.7) with 97.1% specificity (95% CI:84.7,99.9) in 'Definite ATB' and 'Probable ATB' group collectively. The sensitivity increased to 70.9% (95% CI:51.9,85.8) in the combined 'Definite', 'Probable' and 'Possible' ATB group with similar specificity. The cfMTB-DNA qPCR assay performed significantly better than the Xpert assay which demonstrated a poor sensitivity of ≤16.7% with 100% (95% CI:89.7,100) specificity (p<0.001). We conclude that cfMTB-DNA qPCR assay is an accurate molecular test that can provide direct evidence of M. tuberculosis etiology and has promise to pave the way for improving ATB diagnosis.

Diagnostic Value of Interferon-Gamma Release Assays Combined with Multiple Indicators for Tuberculous Peritonitis

Objective

To investigate the diagnostic value of interferon-gamma release assays combined with multiple indicators for tuberculous peritonitis.

Methods

Patients who were admitted to the hospital due to suspected tuberculous peritonitis were prospectively included during the 30-month study period. Moreover, healthy individuals were recruited and included in the control group. All the study participants were assessed using various indexes, such as interferon-gamma release assays.

Results

A total of 180 patients with suspected tuberculous peritonitis were enrolled, and 24 were excluded. 73 patients with a confirmed diagnosis of tuberculous peritonitis were included in the tuberculous peritonitis group, 83 patients with other diseases in the other-disease control group, and 52 healthy individuals in the control group. Moreover, 83 patients in the other-disease control group and 52 participants in the control group were identified as 135 nontuberculous peritonitis patients. The area under the receiver operating characteristics curve for the QuantiFERON-TB test was 0.851 (95% confidence interval: 0.799–0.903), and the optimal cutoff value was 0.55 IU/mL, which corresponds to a sensitivity and specificity of 86.30% and 80.00%, respectively. The receiver operating characteristic curves for the combination of the QuantiFERON-TB test and the use of erythrocyte sedimentation rate, serum adenosine deaminase level, serum cancer antigen 125 level, and hypersensitive C-reactive protein level had an area under the curve of 0.859 (95% confidence interval: 0.809–0.909), with a sensitivity and specificity of 97.26% and 62.96%, respectively.

Conclusions

The combined use of the QuantiFERON-TB test and multiple indexes can significantly improve the accuracy of diagnosing tuberculous peritonitis.

Abdominal Tuberculosis Managed Surgically in the Late Phase: A Case Report

About 1-5 % of cases of tuberculosis (TB) have uncommon abdominal conditions, and affect primarily young adults. The clinical diagnosis is challenging and often delayed due to the symptoms being non-specific and may be confused with other bowel diseases, therefore resulting in significant morbidity and mortality. A 27-year-old man was brought to our emergency department with the complaints a fever and abdominal pain. According to the chest X-ray findings taken 24 hours previously, pulmonary TB was suspected. Abdominal TB associated intestinal obstruction, ascites and lymphadenopathy were found by computed tomography and exploratory laparotomy. He was treated surgically by segmental resection, however passed away due to severe bleeding caused by the recurrence of perforation of the small intestine and sepsis. This case of systemic TB highlights the difficulties in diagnosis and treatment in time. The early diagnosis and timely treatment are both necessary to manage the disease successfully.

Abdominal ultrasound for diagnosing abdominal tuberculosis or disseminated tuberculosis with abdominal involvement in HIV-positive individuals

BACKGROUND

Accurate diagnosis of tuberculosis in people living with HIV is difficult. HIV-positive individuals have higher rates of extrapulmonary tuberculosis and the diagnosis of tuberculosis is often limited to imaging results. Ultrasound is such an imaging test that is widely used as a diagnostic tool (including point-of-care) in people suspected of having abdominal tuberculosis or disseminated tuberculosis with abdominal involvement.

OBJECTIVES

To determine the diagnostic accuracy of abdominal ultrasound for detecting abdominal tuberculosis or disseminated tuberculosis with abdominal involvement in HIV-positive individuals.To investigate potential sources of heterogeneity in test accuracy, including clinical setting, ultrasound training level, and type of reference standard.

SEARCH METHODS

We searched for publications in any language up to 4 April 2019 in the following databases: MEDLINE, Embase, BIOSIS, Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Conference Proceedings Citation Index- Science (CPCI-S), and also ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform to identify ongoing trials.

SELECTION CRITERIA

We included cross-sectional, cohort, and diagnostic case-control studies (prospective and retrospective) that compared the result of the index test (abdominal ultrasound) with one of the reference standards. We only included studies that allowed for extraction of numbers of true positives (TPs), true negatives (TNs), false positives (FPs), and false negatives (FNs). Participants were HIV-positive individuals aged 15 years and older. A higher-quality reference standard was the bacteriological confirmation of Mycobacterium tuberculosis from any clinical specimen, and a lower-quality reference standard was a clinical diagnosis of tuberculosis without microbiological confirmation. We excluded genitourinary tuberculosis.

DATA COLLECTION AND ANALYSIS

For each study, two review authors independently extracted data using a standardized form. We assessed the quality of studies using a tailored Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. We used the bivariate model to estimate pooled sensitivity and specificity. When studies were few we simplified the bivariate model to separate univariate random-effects logistic regression models for sensitivity and specificity. We explored the influence of the type of reference standard on the accuracy estimates by conducting separate analyses for each type of reference standard. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 11 studies. The risks of bias and concern about applicability were often high or unclear in all domains. We included six studies in the main analyses of any abnormal finding on abdominal ultrasound; five studies reported only individual lesions.The six studies of any abnormal finding were cross-sectional or cohort studies. Five of these (83%) were conducted in low- or middle-income countries, and one in a high-income country. The proportion of participants on antiretroviral therapy was none (1 study), fewer then 50% (4 studies), more than 50% (1 study), and not reported (5 studies). The first main analysis, studies using a higher-quality reference standard (bacteriological confirmation), had a pooled sensitivity of 63% (95% confidence interval (CI) 43% to 79%; 5 studies, 368 participants; very low-certainty evidence) and a pooled specificity of 68% (95% CI 42% to 87%; 5 studies, 511 participants; very low-certainty evidence). If the results were to be applied to a hypothetical cohort of 1000 people with HIV where 200 (20%) have tuberculosis then:- About 382 individuals would have an ultrasound result indicating tuberculosis; of these, 256 (67%) would be incorrectly classified as having tuberculosis (false positives).- Of the 618 individuals with a result indicating that tuberculosis is not present, 74 (12%) would be incorrectly classified as not having tuberculosis (false negatives).In the second main analysis involving studies using a lower-quality reference standard (clinical diagnosis), the pooled sensitivity was 68% (95% CI 45% to 85%; 4 studies, 195 participants; very low-certainty evidence) and the pooled specificity was 73% (95% CI 41% to 91%; 4 studies, 202 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

In HIV-positive individuals thought to have abdominal tuberculosis or disseminated tuberculosis with abdominal involvement, abdominal ultrasound appears to have 63% sensitivity and 68% specificity when tuberculosis was bacteriologically confirmed. These estimates are based on data that is limited, varied, and low-certainty.The low sensitivity of abdominal ultrasound means clinicians should not use a negative test result to rule out the disease, but rather consider the result in combination with other diagnostic strategies (including clinical signs, chest x-ray, lateral flow urine lipoarabinomannan assay (LF-LAM), and Xpert MTB/RIF). Research incorporating the test into tuberculosis diagnostic algorithms will help in delineating more precisely its value in diagnosing abdominal tuberculosis or disseminated tuberculosis with abdominal involvement.

Massive infected ascites in an immunocompetent patient with gastrointestinal tuberculosis

Mycobacterium tuberculosisis highly endemic in the Philippines. The diagnosis is challenging with its non-specific presentation and the organism could extend to any of the organs. Interestingly, bacterial peritonitis arising spontaneously from gastrointestinal tuberculosis (TB) in an otherwise healthy, non-cirrhotic patient is quite unusual. In this paper, we discuss the case of a 27-year-old HIV-seronegative woman with massive intraperitoneal mixed bacterial and tuberculous abscess presenting 20 months after being diagnosed with bacteriologically confirmed gastrointestinal TB. Repeated large-volume paracentesis was done to drain out the infected ascites instead of inserting a percutaneously implanted catheter. Clinical improvement was noted and she was discharged after 12 days of intravenous antibiotics. She had completed 6 months of antituberculosis therapy and been well since then. The case has demonstrated that repeated paracentesis along with appropriate antibiotic regimen, may be a viable option for patients with TB and bacterial coinfected peritonitis. And possibly, peritoneal TB may increase the risk for (spontaneous) bacterial peritonitis.

Isolated gastric varices secondary to abdominal tuberculosis mimicking lymphoma: a case report

Background

Abdominal tuberculosis (TB) rarely presents with abdominal masses and rarely causes isolated gastric varices.

Case presentation

We report a case of isolated gastric varices secondary to abdominal TB mimicking lymphoma. A 42-year-old woman without any history of liver disease presented with melena and mild abdominal pain. Upon admission to the hospital, laboratory investigations revealed a hemoglobin level of 76 g/L. Gastroduodenoscopic examination showed isolated gastric fundal varices with red color signs. Abdominal contrast-enhanced computed tomography (CECT) revealed non-enhanced masses of soft-tissue density in the lesser omental and the retropancreatic areas, multiple para-aortic lymph nodes, and multiple small hypodense splenic lesions. Positron emission tomography-CT showed hypermetabolic [F-18]2-fluoro-2-deoxyglucose activity involving multiple regional lymph nodes and the bone marrow, suggestive of lymphoma. Bone marrow biopsy revealed no abnormality. Histopathological examination of a CT-guided biopsy specimen showed granulomatous inflammation with necrosis and microorganisms that stained positive with acid-fast stains. Abdominal CECT showed a decrease in the size of the lesser omental and peripancreatic masses, as well as the para-aortic lymph nodes after 4-month anti-TB therapy.

Conclusions

TB should be considered among the differential diagnoses in patients with abdominal masses, isolated gastric varices, and regional lymphadenopathy. Prompt and definitive diagnosis of abdominal TB requires a coordinated approach involving laboratory tests, radiological examination, and invasive procedures for optimal decision making and management.

Clinical features and outcomes of abdominal tuberculosis in southeastern Korea: 12 years of experience

Background

Abdominal tuberculosis (TB) is an uncommon form of infection with Mycobacterium tuberculosis in Korea. In this study, we aimed to highlight the clinical features, diagnostic methods, and outcomes of abdominal TB over 12 years in Southeastern Korea.

Methods

A total of 139 patients diagnosed as having abdominal TB who received anti-TB medication from January 2005 to June 2016 were reviewed. Among them, 69 patients (49.6%) had luminal TB, 28 (20.1%) had peritoneal TB, 7 (5.0%) had nodal TB, 23 (16.5%) had visceral TB, and 12 (8.6%) had mixed TB.

Results

The most frequent symptoms were abdominal pain (34.5%) and abdominal distension (21.0%). Diagnosis of abdominal TB was confirmed using microbiologic and/or histologic methods in 76 patients (confirmed diagnosis), while the remaining 63 patients were diagnosed based on clinical presentation and radiologic imaging (clinical diagnosis). According to diagnostic method, frequency of clinical diagnosis was highest in patients with luminal (50.7%) or peritoneal (64.3%) TB, while frequency of microscopic diagnosis was highest in patients with visceral TB (68.2%), and frequency of histologic diagnosis was highest in patients with nodal TB (85.2%). Interestingly, most patients, except those with nodal TB, showed a good response to anti-TB agents, with 84.2% showing a complete response. The mortality rate was only 1.4% in the present study.

Conclusions

Most patients responded very well to anti-TB therapy, and surgery was required in only a minority of cases of suspected abdominal TB.

Abdominal tuberculosis: Is there a role for surgery?

It is important that surgeons are familiar with the various manifestations of tuberculosis (TB). Although TB has been declining in incidence in the developed world, it remains an important problem in endemic areas of the developing world. The aim of the review was to elucidate the natural history and characteristics of abdominal TB and ascertain the indications for surgery. TB can affect the intestine as well as the peritoneum and the most important aspect of abdominal TB is to bear in mind the diagnosis and obtain histological evidence. Abdominal TB is generally responsive to medical treatment, and early diagnosis and management can prevent unnecessary surgical intervention. Due to the challenges of early diagnosis, patients should be managed in collaboration with a physician familiar with anti-tuberculous therapy. An international expert consensus should determine an algorithm for the diagnosis and multidisciplinary management of abdominal TB.

Tuberculous Peritonitis

Tuberculous peritonitis is rare in the United States but continues to be reported to occur in certain high-risk populations, which include patients with AIDS or cirrhosis, patients on continuous ambulatory peritoneal dialysis, recent immigrants from areas of high endemicity, and those who are immunosuppressed. The diagnosis of this disease requires a high clinical index of suspicion and should be considered in the differential of ascites with a lymphocyte predominance and serum-ascitic albumin gradient of <1.1 mg/dl. Microbiological or pathological confirmation remains the gold standard for diagnosis. Ascitic fluid cultures have low yield, but peritoneoscopy with biopsy or cultures frequently confirms the diagnosis. Newer techniques with future application include determination of adenosine deaminase and interferon gamma levels in ascitic fluid. Ultrasound and computed tomography are frequently used to guide fluid aspiration and biopsies. Six months of treatment with antituberculosis therapy is adequate except in cases of drug-resistant tuberculosis. The role of steroids remains controversial. Surgical approaches may be required to deal with complications including bowel perforation, intestinal obstruction from adhesions, fistula formation, or bleeding.

Intestinal tuberculosis: a diagnostic challenge

OBJECTIVE

To describe characteristics, presentation, time to diagnosis and diagnostic findings of patients with intestinal tuberculosis (ITB) in a low-burden country.

METHOD

Retrospective study of 61 consecutive ITB patients diagnosed between 2008 and 2014 at a large East London hospital.

RESULTS

Forty of sixty-one patients were male. Mean age was 34.6 years. 93% of patients were born abroad, mostly from TB-endemic areas (Indian subcontinent: 88%, Africa: 9%). 25% had concomitant pulmonary TB. Median time from symptom onset to ITB diagnosis was 13 weeks (IQR 3-26 weeks). Ten patients were initially treated for IBD, although patients had ITB. The main sites of ITB involvement were the ileocaecum (44%) or small bowel (34%). Five patients had isolated perianal disease. Colonoscopy confirmed a diagnosis of ITB in 77% of those performed. 42 of 61 patients had a diagnosis of ITB confirmed on positive histology and/or microbiology.

CONCLUSION

Diagnosis of ITB is often delayed, which may result in significant morbidity. ITB should be excluded in patients with abdominal complaints who come from TB-endemic areas to establish prompt diagnosis and treatment. Diagnosis is challenging but aided by axial imaging, colonoscopy and tissue biopsy for TB culture and histology.

[Extrapulmonary tuberculosis]

Each year, there are more than eight million new cases of tuberculosis and 1.3 million deaths. There is a renewed interest in extrapulmonary forms of tuberculosis as its relative frequency increases. Among extrapulmonary organs, pleura and lymph nodes are the most common. Their diagnosis is often difficult and is based on clinical, radiological, bacteriological and histological findings. Extrapulmonary lesions are paucibacillary and samplings, in most cases, difficult to obtain, so diagnosis is often simply presumptive. Nucleic acid amplification tests, which are fast and specific, have greatly facilitated the diagnosis of some forms of extrapulmonary tuberculosis. However, their sensitivity is poor and a negative test does not eliminate the diagnosis. Treatment is the same as for pulmonary forms, but its duration is nine to 12 months for central nervous system and for bone tuberculosis. Corticosteroids are indicated in meningeal and pericardial localizations. Complementary surgery is used for certain complicated forms.

Disseminated tuberculosis presenting as tuberculous peritonitis and sepsis tuberculosa gravissima in a patient with cirrhosis of the liver: A diagnosis of challenge

We report the case of an 81-year-old man diagnosed with liver cirrhosis complicated by spontaneous bacterial peritonitis and septic shock. Mycobacterium tuberculosis complex was isolated from the ascites, sputum, and blood culture 1 month after the patient died. Clinicians should be aware of the unusual diagnosis of sepsis tuberculosa gravissima presenting with tuberculous peritonitis, which is easily misdiagnosed as spontaneous bacterial peritonitis and Gram-negative bacillus sepsis in patients with cirrhosis. Clinicians should cautiously evaluate the patient's sputum, gastric contents, urine, cerebrospinal fluid, and bone marrow for early diagnosis of disseminated tuberculosis in patients with a high degree of suspicion of this diagnosis.

Impact of pulmonary and extrapulmonary tuberculosis infection in kidney transplantation: a nationwide population-based study in Taiwan

BACKGROUND

Tuberculosis (TB) has been reported to increase morbidity after kidney transplantation and pose a therapeutic challenge. However, population-based research, specifically focused on the association between kidney transplantation and subsequent pulmonary or extrapulmonary TB, is lacking.

METHODS

A nationwide population-based study was conducted using Taiwan's National Health Insurance Research Database, which provided claims data belonging to kidney transplant recipients during 1997-2006. Multivariate analysis was used to identify independent risk factors for TB after kidney transplantation. Kaplan-Meier survival analysis was used to assess the outcome of patients with TB.

RESULTS

Among 4554 kidney transplant recipients over the 10-year period, 109 (2.4%) patients with newly diagnosed TB were identified: 75 patients with only pulmonary involvement, and 34 with extrapulmonary spread. The incidence of kidney transplant recipients developing TB was 638 per 100,000 person-years. The independent risk factors for post-transplant TB included cyclosporine-based immunosuppressant agents during the first year after kidney transplantation (odds ratio [OR]: 1.98, P = 0.001), hepatitis C infection (OR: 1.79, P = 0.024), and chronic obstructive pulmonary disease (OR: 1.50, P = 0.041). Kidney transplant recipients who developed TB had a lower 5-year survival rate than those who did not (78.6% vs. 93.4%, P = 0.001).

CONCLUSIONS

Kidney transplant recipients in Taiwan did have a high risk of TB infection, with high proportion of extrapulmonary spread. Physicians need to be vigilant in surveying for TB in kidney transplantation, especially in high-risk patients.

Peritoneal tuberculosis in Qatar: a five-year hospital-based study from 2005 to 2009

There is limited information about peritoneal tuberculosis in Qatar. This retrospective study aimed to review our experience with peritoneal tuberculosis in patients admitted to Hamad general hospital over a period of 5 years, from 2005 to 2009, with emphasis on presentation, investigation, diagnosis and therapeutic outcome. Fifty-four patients with peritoneal tuberculosis identified during the study period were included. The mean age of them was 31.85 years and 96.3% (52/54) of them were non-Qataris with male predominance. The main symptoms and signs at the time of presentation were abdominal pain and ascites respectively. Underlying diseases were described in 24% (13/54) and history of contact with tuberculous cases was present in 31.5% (17/54) of patients. Tuberculin test was positive in 66.7% (36/54). The ascitic fluid smear showed acid fast bacilli in 2% (1/53), and culture was positive in 39.6% (21/53) of cases. Laparoscopically obtained peritoneal biopsy showed caseating granulomas in 93% (40/43) and mycobacteria were identified by acid fast staining and culture in 58.5% (24/41) and 98% (40/41) of the tested specimens respectively. Most of the patients (84%; 37/44) who had completed their therapy in Qatar improved with antituberculosis therapy, and only one patient died. In conclusion, the clinical features and the imaging findings of the disease were non-specific. A high index of suspicion is essential for early diagnosis. Culture of ascitic fluid delayed the diagnosis in clinically suspected cases, whereas laparoscopically guided peritoneal biopsy provided rapid and correct diagnosis. A Six-month course with antituberculous therapy was effective and improved the outcome.

Antioxidative status of patients with alcoholic liver disease in southeastern Taiwan

AIM: To investigate the antioxidative status of patients with alcoholic liver disease (ALD) in southeastern Taiwan.

METHODS: Our study comprised 27 patients with ALD recruited from Taitung Mackay Memorial Hospital, located in southeastern Taiwan. Patients with ALD included 12 non-aborigines (12 men) and 15 aborigines (11 men and 4 women). According to the severity of ALD, patients with ALD included 10 with hepatitis (9 men and 1 woman) and 17 with cirrhosis (14 men and 3 women). Twenty-two age- and gender-matched healthy adults served as the control group in this study. Venous blood (10 mL) of each subject was drawn into EDTA-containing tubes after 8 h overnight fasting.

RESULTS: Compared to the control group, patients with ALD showed significantly lower erythrocytic catalase (11.1 ± 0.7 U/mg Hb vs 8.0 ± 0.7 U/mg Hb, P < 0.05) and superoxide dismutase (9.5 ± 1.6 U/mg Hb vs 3.0 ± 0.2 U/mg Hb, P < 0.05) activities. Furthermore, the erythrocytic reduced glutathione/oxidized glutathione ratio was significantly lower in ALD patients than that in the control group (38.1 ± 5.4 vs 15.7 ± 1.9, P < 0.05). The results revealed that patients with ALD experienced more oxidative stress than those in the control group. The non-aboriginal, but not the aboriginal, ALD group had higher erythrocytic glutathione peroxidase (GPX) activity than that in the control group (46.1 ± 7.8 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05). Hepatitis, but not cirrhosis, ALD patients had higher erythrocytic GPX activity than that in the control group (44.3 ± 8.6 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05).

CONCLUSION: Our results indicate that both ethnicity and the severity of ALD may cause different erythrocytic antioxidative enzyme activities especially GPX activity.

Intestinal tuberculosis

PURPOSE OF REVIEW

Intestinal tuberculosis (TB) is increasing due partly to the HIV pandemic. Its clinical presentation mimics inflammatory conditions such as Crohn's disease and malignancies, which are becoming more prevalent, so the diagnosis is problematic.

RECENT FINDINGS

Greater awareness of intestinal TB is needed, both in countries where TB is endemic and developed countries with immigrant populations. Some strains of Mycobacterium tuberculosis are associated with more extrapulmonary disease and greater dissemination, thereby exacerbating the rise in HIV-associated extrathoracic TB. Recent retrospective and prospective studies are leading to the development of diagnostic algorithms. A wide range of imaging techniques is available for sampling and diagnosis. New biochemical, immunological and molecular diagnostic methods are being developed but must be standardized and validated. Developments in drug delivery will facilitate oral therapy even in patients suffering from malabsorption.

SUMMARY

There is an increasing consensus on the risk factors and clinical presentations of intestinal TB. Imaging techniques, coupled with fine needle biopsies, are useful aids to diagnosis, but most important is a greater awareness of the condition by clinicians.

Diagnosis of abdominal tuberculosis by T-cell-based assays on peripheral blood and peritoneal fluid mononuclear cells

OBJECTIVES

Diagnosing abdominal tuberculosis (TB) remains a challenge. A recently developed RD-1 gene-based assay for diagnosing tuberculosis infection shows promising results. We evaluated the diagnostic usefulness of this assay compared with conventional tests in patients with suspected abdominal TB in clinical practice.

METHODS

All patients with suspected abdominal TB were prospectively enrolled in a tertiary hospital during a 1-year period. In addition to the conventional tests for diagnosing TB, the IFN-gamma-producing T-cell response to ESAT-6 and CFP-10 by ELISPOT assay using peripheral blood mononuclear cells (PBMC) and peritoneal fluid mononuclear cells (PF-MC) were performed.

RESULTS

Forty eight patients with suspected abdominal TB were enrolled. Of these patients, 30 (63%) were classified as abdominal TB including 14 TB peritonitis (12 confirmed + 1 probable + 1 possible), 6 abdominal TB lymphadenitis (3 confirmed + 3 probable), 4 hepatic TB (3 confirmed + 1 possible), 2 intestinal TB (1 confirmed + 1 probable), 3 renal TB (1 confirmed + 2 probable), and 1 pancreatic TB (1 confirmed). Eighteen (38%) were classified as not TB. ELISPOT assay using PBMC was performed on samples from all 48 subjects. The sensitivity and specificity of the PBMC ELISPOT assay were 89% (95% CI, 71-98%) and 78% (95% CI, 52-94%), respectively. In the 11 patients in whom PF-MC ELISPOT assay was performed, it was positive in 5 of 6 patients with TB peritonitis, and negative in all 5 patients with not TB.

CONCLUSIONS

The ELISPOT assay using PBMC and PF-MC is a useful adjunct to the current tests for diagnosing abdominal TB.