Diagnostic value of adenosine deaminase in ascites for tuberculosis ascites: a meta-analysis

Mistakes to avoid in the management of abdominal tuberculosis

INTRODUCTION

The diagnosis and management of abdominal tuberculosis, i.e Gastrointestinal Tuberculosis (GITB) and tuberculous peritonitis (TBP) is challenging. Abdominal tuberculosis, presenting usually with abdominal pain, intestinal obstruction, and constitutional symptoms, is typically a paucibacillary condition. The diagnosis hinges on a correct interpretation of clinical, radiological, histological, biochemical, and microbiological findings as also appropriately assessing response to therapy.

AREAS COVERED

The authors review potential missteps that could occur in managing GITB and TBP sourced from published literature and clinical experience. These include avoiding excess use of tests with limited accuracy, understanding limitations of ascitic adenosine deaminase (ADA) and granulomas, avoiding empirical antitubercular therapy (ATT) where possible but also understanding that microbiological tests may not always be positive, and finally not to bank solely on subjective clinical responses but to use objective markers in assessing response to therapy. In addition, diagnosis of predisposing immunosuppressed states, attention to nutrition, appropriate management of sequelae with endoscopic dilatation/surgery, and early surgery when indicated are some of the additional issues discussed.

EXPERT OPINION

In future, a more secure diagnosis banking on the use of better microbiological tools, multiparameter-based models, artificial intelligence-based approaches, and use of advances in -omics-based approaches can improve diagnosis and avoid some missteps.

A Review of Current Practices and Future Trends in Body Fluid Testing

BACKGROUND

Body fluid testing in the clinical chemistry laboratory is a cornerstone in the diagnostic workup of pathological effusions. Laboratorians may not be aware of the preanalytical workflows used in the collection of body fluids though the value is evident whenever processes change or issues arise. The analytical validation requirements can vary depending on the regulations dictated by the laboratories' jurisdiction and accreditor requirements. Much of analytical validation hinges on how useful testing is to clinical care. Usefulness of testing varies with how well established and incorporated the tests and interpretation are in practice guidelines.

CONTENT

Body fluid collections are depicted and described so clinical laboratorians have a basic appreciation of what specimens are submitted to the laboratory for testing. A review of validation requirements by major laboratory accreditation entities is presented. A review of the usefulness and proposed decision limits for common body fluid chemistry analytes is presented. Body fluid tests that show promise and those that are losing (or lost long ago) value are also reviewed.

SUMMARY

The total testing process from collection to result interpretation can be complicated and easily overlooked by the clinical laboratory. This review aims to improve the understanding and awareness of collections, validation, result interpretation, and provide an update on recent trends.

[Extrapulmonary tuberculosis]

Extrapulmonary tuberculosis (TB) presents unique diagnostic and therapeutic challenges. The site of involvement can vary widely, with common sites including the lymph nodes, pleura, skin, ear, nose and throat, genitourinary system, pericardium, gastrointestinal tract, bones and joints, and central nervous system. Clinical manifestations of extrapulmonary TB are diverse and often non-specific. Diagnosis is based on a combination of clinical suspicion, imaging, histopathology, and microbiology. Treatment of extrapulmonary TB generally follows similar principles to pulmonary TB, but the duration of treatment depends on the site of involvement and the extent of the disease. Increased awareness among healthcare providers is essential for the timely recognition and effective management of extrapulmonary TB cases.

An Updated Systematic Review and Meta-Analysis for the Diagnostic Test Accuracy of Ascitic Fluid Adenosine Deaminase in Tuberculous Peritonitis

BACKGROUND

Tuberculous peritonitis is difficult to diagnose due to its non-specific clinical manifestations and lack of proper diagnostic modalities. Current meta-analysis was performed to find the overall diagnostic accuracy of adenosine deaminase (ADA) in diagnosing tuberculous peritonitis.

MATERIALS AND METHODS

PubMed, Google Scholar, and Cochrane library were searched to retrieve the published studies which assessed the role of ascitic fluid ADA in diagnosing tuberculous peritonitis from Jan 1980 to June 2022. This meta-analysis included 20 studies and 2,291 participants after fulfilling the inclusion criteria.

RESULTS

The pooled sensitivity was 0.90 (95% confidence interval [CI]: 0.85 - 0.94) and pooled specificity was 0.94 (95% CI: 0.92 - 0.95). The positive likelihood ratio was 15.20 (95% CI: 11.70 - 19.80), negative likelihood ratio was 0.10 (95% CI: 0.07 - 0.16) and diagnostic odds ratio was 149 (95% CI: 86 - 255). The area under the summary receiver operating characteristic curve was 0.97. Cut- off value and sample size were found to be the sources of heterogeneity in the mete-regression analysis.

CONCLUSION

Ascitic fluid ADA is a useful test for the diagnosis of tuberculous peritonitis with good sensitivity and specificity however, with very low certainty of evidence evaluated by Grading of Recommendations, Assessment, Development and Evaluation approach. Further well- designed studies are needed to validate the diagnostic accuracy of ascitic fluid ADA for tuberculous peritonitis.

Peritoneal and Pulmonary Tuberculosis in a Postpartum Female with Elevated Cancer Antigen 125 and Ascites

BACKGROUND

Peritoneal tuberculosis is a rare form of extrapulmonary tuberculosis and presents a challenging diagnosis because of its nonspecific clinical manifestations. Peritoneal TB mimics other pathologies, including abdominal carcinomatosis, especially when the patient presents with ascites and an elevated cancer antigen (CA)-125 levels. Case Presentation. A postpartum 20-year-old Hispanic female recently discharged after transverse cesarean surgery, presented to the ER with fever, chills, edema, abdominal distension, nausea, and vomiting. The patient was febrile, tachycardic, and hypotensive. Chest X-ray demonstrated alveolar and interstitial consolidations; chest CT revealed tree-in-bud opacities in the right lower lobe, suggestive of atypical (TB)/fungal infection. CT of the abdomen and pelvis demonstrated ascites, omental thickening, peritoneal thickening, and mesenteric adenopathy, suggestive of carcinomatosis. She was admitted with a presumed diagnosis of sepsis secondary to pneumonia and started empirically on broad-spectrum antibiotics without clinical improvement. A battery of oncology markers was ordered and revealed a mildly elevated cancer antigen (CA)-125. Diagnostic paracentesis showed lymphocytic predominance with positive mycobacteria PCR, elevated adenosine deaminase (ADA), and no malignant cells. Subsequently, the sputum acid-fast bacilli (AFB) stain returned positive for tuberculosis, confirming the diagnosis of pulmonary tuberculosis. A peritoneal biopsy was obtained and demonstrated caseating granulomas consistent with peritoneal tuberculosis. The patient was started on standard antituberculosis therapy with clinical improvement.

CONCLUSIONS

This case highlights the need for a high-level of suspicion for peritoneal tuberculosis in a patient with pulmonary tuberculosis who presents with intra-abdominal ascites, omental thickening, peritoneal thickening, and mesenteric lymphadenopathy, despite the presence of an elevated CA-125 level.

Diagnostic performance of adenosine deaminase for abdominal tuberculosis: A systematic review and meta-analysis

Background and aim

Abdominal tuberculosis (TB) is a common type of extrapulmonary TB with an insidious onset and non-specific symptoms. Adenosine deaminase (ADA) levels increase rapidly in the early stages of abdominal TB. However, it remains unclear whether ADA serves as a diagnostic marker for abdominal TB.

Methods

We performed a systematic literature search for relevant articles published in PubMed, Web of Science, Cochrane Library, and Embase up to April 2022. First, we used the Quality Assessment of Diagnostic Accuracy Studies tool-2 (QUADAS-2), to evaluate the quality of the included articles. Bivariate and hierarchical summary receiver operating characteristic (HSROC) models were then utilized to analyze pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the receiver operating characteristic curve (AUROC). In addition, we explored a subgroup analysis for potential heterogeneity and publication bias among the included literature.

Results

Twenty-four articles (3,044 participants, 3,044 samples) which met the eligibility criteria were included in this study. The pooled sensitivity and specificity of ADA for abdominal TB detection were 93% [95% confidence interval (CI): 0.89-0.95] and 95% (95% CI: 0.93-0.96), respectively. PLR and NLR were 18.6 (95% CI: 14.0-24.6) and 0.08 (95% CI: 0.05-0.12), respectively. DOR and AUROC were 236 (95% CI: 134-415) and 0.98 (95% CI: 0.96-0.99), respectively. Furthermore, no heterogeneity or publication bias was found.

Conclusions

Our meta-analysis found ADA to be of excellent diagnostic value for abdominal TB and could be used as an auxiliary diagnostic tool.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022297931.

Recent updates in diagnosis of abdominal tuberculosis with emphasis on nucleic acid amplification tests

INTRODUCTION

Abdominal tuberculosis (TB) is a common epitome of extrapulmonary TB (EPTB), wherein peritoneal and intestinal TB are the most prevalent forms. Diagnosis of abdominal TB is a daunting challenge owing to variable anatomical locations, paucibacillary nature of specimens and atypical clinical presentations that mimic other abdominal diseases, such as Crohn's disease and malignancies. In this review, we made a comprehensive study on the diagnosis of abdominal TB.

AREA COVERED

Various modalities employed for abdominal TB diagnosis include clinical features, imaging, bacteriological tests (smear/culture), histopathological/cytological observations, interferon-gamma release assays and nucleic acid amplification tests (NAATs). Among NAATs, loop-mediated isothermal amplification assay, PCR, multiplex-PCR, nested PCR, real-time PCR and GeneXpert® MTB/RIF were discussed. Identification of circulating Mycobacterium tuberculosis cell-free DNA by real-time PCR within ascitic fluids is another useful approach.

EXPERT OPINION

Several novel molecular/immunological methods, such as GeneXpert Ultra, aptamer-linked immobilized sorbent assay, immuno-PCR (I-PCR) and nanoparticle-based I-PCR have recently been developed for detecting pulmonary TB and several EPTB types, which may also be explored for abdominal TB diagnosis. Precise and prompt diagnosis of abdominal TB may initiate an early therapy so as to reduce the complications, i.e. abdominal pain, ascites, abdominal distension, intestinal obstruction/perforation, etc., and avoid surgical involvement.Plain Language SummaryAbdominal tuberculosis (TB) is a manifestation of extrapulmonary TB (EPTB), where peritoneal and intestinal TB are two major forms. Diagnosis of abdominal TB is difficult owing to low bacterial load present in clinical samples and non-specific clinical presentations as it mimics other diseases such as inflammatory bowel diseases, abdominal malignancies, etc. Bacteriological tests (smear/culture) almost fail owing to poor sensitivities and it is not always possible to get representative tissue samples for histopathological and cytological observations. In recent years, molecular tests i.e. nucleic acid amplification tests (NAATs), such as PCR/multiplex-PCR (M-PCR), nested PCR and GeneXpert are widely employed. Markedly, PCR/M-PCR and nested PCR exhibited reasonable good sensitivities/specificities, while GeneXpert revealed low sensitivity in most of the studies but high specificity, thus it could assist in differential diagnosis of intestinal TB and Crohn's disease. Further, novel molecular/immunological tests employed for pulmonary TB and other EPTB types were described and those tests can also be utilized to diagnose abdominal TB. Reliable and rapid diagnosis of abdominal TB would initiate an early start of anti-tubercular therapy and reduce the severe complications.

Serum Biomarker Profile Including CCL1, CXCL10, VEGF, and Adenosine Deaminase Activity Distinguishes Active From Remotely Acquired Latent Tuberculosis

Introduction

There is an urgent medical need to differentiate active tuberculosis (ATB) from latent tuberculosis infection (LTBI) and prevent undertreatment and overtreatment. The aim of this study was to identify biomarker profiles that may support the differentiation between ATB and LTBI and to validate these signatures.

Materials and Methods

The discovery cohort included adult individuals classified in four groups: ATB (n = 20), LTBI without prophylaxis (untreated LTBI; n = 20), LTBI after completion of prophylaxis (treated LTBI; n = 20), and healthy controls (HC; n = 20). Their sera were analyzed for 40 cytokines/chemokines and activity of adenosine deaminase (ADA) isozymes. A prediction model was designed to differentiate ATB from untreated LTBI using sparse partial least squares (sPLS) and logistic regression analyses. Serum samples of two independent cohorts (national and international) were used for validation.

Results

sPLS regression analyses identified C-C motif chemokine ligand 1 (CCL1), C-reactive protein (CRP), C-X-C motif chemokine ligand 10 (CXCL10), and vascular endothelial growth factor (VEGF) as the most discriminating biomarkers. These markers and ADA(2) activity were significantly increased in ATB compared to untreated LTBI (p ≤ 0.007). Combining CCL1, CXCL10, VEGF, and ADA2 activity yielded a sensitivity and specificity of 95% and 90%, respectively, in differentiating ATB from untreated LTBI. These findings were confirmed in the validation cohort including remotely acquired untreated LTBI participants.

Conclusion

The biomarker signature of CCL1, CXCL10, VEGF, and ADA2 activity provides a promising tool for differentiating patients with ATB from non-treated LTBI individuals.

Mycobacteria avium-related peritonitis in a patient undergoing peritoneal dialysis: case report and review of the literature

BACKGROUND

Mycobacteria avium (M. avium) is a species of ubiquitous slowly growing nontuberculous mycobacteria. It causes opportunistic infections. However, M. avium-related peritonitis in peritoneal dialysis (PD) patients is rare.

CASE PRESENTATION

A 51-year-old female end-stage kidney disease patient undergoing PD was admitted for a noninfectious complication. She presented catheter exit site drainage and slightly increased PD effluent white cell count (WCC) with polymorphonuclear predominance on admission. Exit site infection and PD-related peritonitis were diagnosed. Repeated cultures of effluent and drainage were negative. Initial empirical antibiotics and further adjustment were not rewarding. PD was terminated 2 weeks later, however, shortly the patient developed stupor, high fever, peritoneal irritation, and spontaneous chylous ascites, and showed elevated ascitic adenosine deaminase (ADA). The manifestations persisted and the patient's general condition deteriorated despite intensified antibiotic therapy. Massive parallel sequencing identified M. avium in ascites on hospital day 25, and 4-drug treatment with azithromycin, amikacin, rifampin, and ethambutol was initiated. Nevertheless, the patient died from sepsis on hospital day 30.

CONCLUSIONS

We report a case of PD-related M. avium peritonitis. Prolonged culture-negative peritonitis, chylous ascites, and elevated ascitic ADA may hint the possibility of mycobacterial infections. Diagnostic method allowing prompt identification of the pathogen is warranted. The prognosis can be extremely poor, and the prophylaxis and treatment should be better defined.

Reappraisal of the Role of Ascitic Fluid Adenosine Deaminase for the Diagnosis of Peritoneal Tuberculosis in Cirrhosis

Backgrounds/Aims

Although peritoneal tuberculosis (TB) is one of the important differential diagnoses among cirrhotic patients with ascites, a peritoneal biopsy is not always available. High ascitic fluid adenosine deaminase (ADA) has been indicative of peritoneal TB. On the other hand, studies to assess its diagnostic utility based on the confirmation of peritoneal biopsy in cirrhotic patients are scarce.

Methods

Patients with new-onset ascites were enrolled prospectively from a tertiary hospital. Peritoneal biopsy was applied according to clinical judgment when required. Based on pathology diagnosis of the peritoneum, the diagnostic efficacy of ascitic fluid ADA for peritoneal TB was evaluated in total and cirrhotic patients, respectively.

Results

Among 286 patients enrolled, 78 were diagnosed with peritoneal TB. One hundred and thirty-two patients had cirrhosis, and 30 of those were diagnosed with peritoneal TB. The mean ADA was 72.2 U/L and 22.7 U/L in the peritoneal and non-peritoneal TB group, respectively, among the total study population, and 64.0 U/L and 19.1 U/L in the peritoneal and non-peritoneal TB group, respectively, among the subgroup with cirrhosis. The area under the curve for ADA to diagnose peritoneal TB was 0.96 in the total study population with a cutoff value of 41.1 U/L, and 0.93 in cirrhotic patients with a cutoff value of 39.9 U/L.

Conclusions

The ascitic fluid ADA measurements showed high diagnostic performance for peritoneal tuberculosis in patients with ascites regardless of cirrhosis at a similar cutoff value.

The negative impact of increasing age and underlying cirrhosis on the sensitivity of adenosine deaminase in the diagnosis of tuberculous peritonitis: a cross-sectional study in eastern China

BACKGROUND

Our study aimed to evaluate the correlation between the sensitivity of adenosine deaminase (ADA) testing for the diagnosis of tuberculous peritonitis (TBP) and patient age or cirrhosis status.

METHODS

Clinical data for patients clinically diagnosed with TPB (n = 132) or not (n = 147) were assessed. ADA activity was compared among three age groups (< 45 yr, 45-60 yr, and ≥ 60 yr) and among cirrhosis-related subgroups. Cut-off values for the ADA test were analyzed among three patient populations (young non-cirrhotic, n = 97; older non-cirrhotic, n = 115; cirrhotic, n = 67), and validated in a cohort of 259 participants.

RESULTS

According to the multivariate regression analyses, age < 45 yr is highly predictive of TBP risk. The young non-cirrhotic TBP patients had higher ADA activity than the middle-aged or old controls (p < 0.01). Significantly decreased activity and efficacy of ADA were observed in the cirrhotic subgroup/population, regardless of age or cohort. For the above-mentioned two non-cirrhotic populations in the validation cohort, the ADA test showed excellent performance using thresholds of 30.5 IU/L and 20.5 IU/L, with respective sensitivities of 91.1% and 92.6%.

CONCLUSIONS

ADA activity is negatively associated with increasing age and underlying cirrhosis. Optimizing cut-off values for the ADA test can increase its sensitivity in non-cirrhotic individuals older than 45 years.

Extrapulmonary tuberculosis

Introduction: Tuberculosis (TB) is a major cause of morbidity and mortality globally. Extrapulmonary TB (EPTB) constitutes about 15%-20% of all TB patients, but accounts for 50% among HIV-coinfected. Confirmation of microbial diagnosis of EPTB is usually challenging.Areas covered: Availability of newer imaging modalities like ¹⁸FDG-PET-CT and PET-MRI has facilitated precise anatomical localization of the lesions and mapping the extent of EPTB. The use of image- and endoscopy-guided invasive diagnostic methods has made procurement of tissue/body fluids for diagnostic testing possible. With the advent of universal drug-susceptibility testing, a rapid diagnosis of drug-resistance is now possible in EPTB. Drug-susceptible EPTB usually responds well to first-line anti-TB treatment; TB meningitis, bone and joint TB and lymph node TB requires longer durations of treatment.Expert opinion: Adjunctive use of corticosteroids in the initial period is recommended in the central nervous system and pericardial TB. Surgical intervention is helpful to obtain tissue samples for diagnosis. Adjunctive surgical treatment along with medical treatment is useful in treating complications like hydrocephalus, Pott's spine. Follow-up of EPTB patients is crucial as treatment period is usually prolonged, requires recognition of development of immune reconstitution and inflammatory syndrome (IRIS), monitoring of adverse events, serious adverse events like anti-TB drug-induced hepatotoxicity, organ-related complications, and treatment adherence.

Gastrointestinal tuberculosis: A systematic review of epidemiology, presentation, diagnosis and treatment

Tuberculosis (TB) once considered a disease of the developing world is infrequent in the developing world too. Its worldwide prevalence with a huge impact on the healthcare system both in economic and health terms has prompted the World Health Organization to make it a top priority infectious disease. Tuberculous infection of the pulmonary system is the most common form of this disease, however, extrapulmonary TB is being increasingly recognized and more often seen in immunocompromised situations. Gastrointestinal TB is a leading extrapulmonary TB manifestation that can defy diagnosis. Overlap of symptoms with other gastrointestinal diseases and limited accuracy of diagnostic tests demands more awareness of this disease. Untreated gastrointestinal TB can cause significant morbidity leading to prolonged hospitalization and surgery. Prompt diagnosis with early initiation of therapy can avoid this. This timely review discusses the epidemiology, risk factors, pathogenesis, clinical presentation, current diagnostic tools and therapy.

Diagnostic Value of T-SPOT.TB Assay for Tuberculous Peritonitis: A Meta-Analysis

Background: Tuberculous peritonitis (TP) is a common form of abdominal tuberculosis (TB). Diagnosing TP remains challenging in clinical practice. The aim of the present meta-analysis was to evaluate the diagnostic accuracy of peripheral blood (PB) T-SPOT and peritoneal fluid (PF) T-SPOT for diagnosing TP.

Methods: PubMed, EmBase, Cochrane, Scopus, Google scholar, China national knowledge internet, and Wan-Fang databases were searched for relevant articles from August 1, 2005 to July 5, 2020. Statistical analysis was performed using Stata, Revman, and Meta-Disc software. Diagnostic parameters including pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were determined. Summary receiver operating characteristic curve was used to determine the area under the curve (AUC).

Results: Twelve studies were eligible and included in the meta-analysis. The analysis showed that the pooled sensitivity and specificity of PB T-SPOT in diagnosing TP were 0.91 (95% CI, 0.88–0.94) and 0.78 (95% CI, 0.73–0.81), respectively, while the pooled PLR, NLR, and DOR were 4.05 (95% CI, 2.73–6.01), 0.13 (95% CI, 0.07–0.23), and 37.8 (95% CI, 15.04–94.98), respectively. On the other hand, the summary estimates of sensitivity, specificity, PLR, NLR, and DOR of PF T-SPOT for TP diagnosis were 0.90 (95% CI, 0.85–0.94), 0.78 (95% CI, 0.72–0.83), 6.35 (95% CI, 2.67–15.07), 0.14 (95% CI, 0.09–0.21), and 58.22 (95% CI, 28.76–117.83), respectively. Furthermore, the AUC of PB T-SPOT and PF T-SPOT for TP diagnosis were 0.91 and 0.94, respectively.

Conclusions: Our results indicate that both PB T-SPOT and PF T-SPOT can be served as sensitive approaches for the diagnosis of TP. However, the unsatisfactory specificities of these two methods limit their application as rule-in tests for TP diagnosis. Furthermore, the standardization of the operating procedure of PF T-SPOT is further needed.

Comparative Assessment of Two Strategies for Interpreting Tumor Markers in Ascitic Effusions

BACKGROUND/AIM

There are two strategies for the interpretation of tumor markers (TM) in fluid effusions: i) high cut-off and ii) fluid/serum ratio (F/S) and low cut-off. The objective of this study is to compare these two strategies and to determine whether diagnostic accuracy improves by the identification of possible false positives using Adenosine deaminase (ADA), C reactive protein (CRP) and % of polymorphonuclear cells (%PN).

PATIENTS AND METHODS

We studied 157 ascitic fluids, 74 of which were malignant. ADA, CRP and %PN were determined in ascitic fluid, and Carcinoembryonic antigen (CEA), Cancer antigen 72-4 (CA72-4), Cancer antigen CA19-9 and Cancer antigen 15-3 (CA15-3) in both fluid and serum.

RESULTS

The strategy of high cut-off showed 59.5% sensitivity at 100% specificity. The F/S strategy showed 75.7% sensitivity at 95.2% specificity. Subclassifying cases with ADA, CRP and %PN negative showed 67.5% sensitivity at 100% specificity for high cut-off and for the F/S strategy was 81.7% sensitivity at 98.7% specificity.

CONCLUSION

The strategy of F/S with negative ADA, CRP and %PN allow the best interpretation for TM in the ascitic fluid.

Ultrasound in managing extrapulmonary tuberculosis: a randomized controlled two-center study

BACKGROUND

Patients with clinically suspected tuberculosis are often treated empirically, as diagnosis - especially of extrapulmonary tuberculosis - remains challenging. This leads to an overtreatment of tuberculosis and to underdiagnosis of possible differential diagnoses.

METHODS

This open-label, parallel-group, superiority randomized controlled trial is done in a rural and an urban center in Tanzania. HIV-positive and -negative adults (≥18 years) with clinically suspected extrapulmonary tuberculosis are randomized in a 1:1 ratio to an intervention- or control group, stratified by center and HIV status. The intervention consists of a management algorithm including extended focused assessment of sonography for HIV and tuberculosis (eFASH) in combination with chest X-ray and microbiological tests. Treatment with anti-tuberculosis drugs is started, if eFASH is positive, chest X-ray suggests tuberculosis, or a microbiological result is positive for tuberculosis. Patients in the control group are managed according national guidelines. Treatment is started if microbiology is positive or empirically according to the treating physician. The primary outcome is the proportion of correctly managed patients at 6 months (i.e patients who were treated with anti-tuberculosis treatment and had definite or probable tuberculosis, and patients who were not treated with anti-tuberculosis treatment and did not have tuberculosis). Secondary outcomes are the proportion of symptom-free patients at two and 6 months, and time to death. The sample size is 650 patients.

DISCUSSION

This study will determine, whether ultrasound in combination with other tests can increase the proportion of correctly managed patients with clinically suspected extrapulmonary tuberculosis, thus reducing overtreatment with anti-tuberculosis drugs.

TRIAL REGISTRATION

PACTR, Registration number: PACTR201712002829221, registered December 1st 2017.

Predictive value of omental thickness on ultrasonography for diagnosis of unexplained ascites, an Egyptian centre study

Etiology of ascites of unknown origin varies with geographic area and ethnic origin. Tuberculous peritonitis and peritoneal carcinomatosis constitute a considerable proportion of patients. Differentiation between both is a major challenge. The role of omental thickness (OT) by ultrasonography to predict risk of malignancy in unexplained ascites. This prospective study was done at Kasr Alainy School of Medicine, Cairo University and included 100 adults with unexplained ascites and thickened omentum (>15 mm) on ultrasonography. An expert performed ultrasonography to assess peritoneum and peritoneal cavity and measure OT. Ascites was assessed regarding volume, echogenicity, and loculation. The ascitic fluid was analyzed to measure lactate dehydrogenase, adenosine deaminase, and total leukocytic count. Laparoscopic exploration with biopsy was done for final diagnosis that divided the patients into; TB Group (n = 44) and peritoneal carcinomatosis group (n = 56). Main Outcome Measures were to determine degree of omental thickness as a predictor of malignancy risk in unexplained ascites and other ultrasonographic features to predict malignancy risk including omental echogenicity and results of diagnostic ascitic tapping. We found that OT was greater in the PC group compared to the TB group (24.6 ± 4.6 mm vs. 17.9 ± 3.0 mm, respectively, p < 0.001). Higher frequency of hypoechogenicity, irregular peritoneal surface, omental cakes, and lymph nodes was seen in PC Group. ADA, TLC, and relative lymphocyte count were higher in TB group. Omental thickness ≥19.5 mm has a sensitivity of 89.3%, specificity of 84.1% to diagnose PC. We can conclude that omental thickness >19 mm is a sensitive and specific predictor of malignancy in patients with unexplained ascites.

Measurement of Adenosine Deaminase in Ascitic Fluid Contributed to the Diagnosis in a Case of Tuberculous Peritonitis

A diagnosis of tuberculous peritonitis (TBP) is difficult because of nonspecific manifestation and limited effectiveness of conventional diagnostic tools. Recently, the usability of measurement of ascitic adenosine deaminase (ADA) was shown. We report here a case of TBP in which measurement of ascitic ADA contributed to the diagnosis. A 93-year-old male developed a large amount of ascites. Analyses of the ascitic fluid revealed exudation, though antibiotics treatment was ineffective. Using paracentesis, the ADA level in the ascites was measured and shown to be high. Under suspicion of TBP, an exploratory laparoscopy was performed and a definitive diagnosis of TBP was made.

Tissue Xpert® MTB/RIF Assay in Peritoneal Tuberculosis: To be (Done) or Not to be (Done)

Introduction

Peritoneal tuberculosis (PTB) is a paucibacillary disease with poor mycobacterial yield in ascitic fluid. The Xpert® MTB/RIF assay (Gene Xpert) is a new tool for the diagnosis of tuberculosis (TB) and has not yet been studied on peritoneal tissue. The present study aimed to investigate the yield of the Xpert® MTB/RIF assay on peritoneal tissue obtained at peritoneoscopy.

Methods

This is a retrospective study and the data were collected from hospital records. The patients who underwent peritoneoscopy along with Xpert® MTB/RIF assay on peritoneal tissue were included in this study. Those with proven PTB were considered as cases while those with other diagnoses as controls. Using the reference standard of TB diagnosis, sensitivity, specificity, and accuracy of Xpert® MTB/RIF assay were calculated.

Results

Total of 36 patients was analyzed in this study: 28 as cases and eight as controls. Peritoneoscopy was carried out for diagnosis and biopsy. Histopathology in cases revealed caseating granulomas in 16 while 11 had non-caseating granulomas. Nine patients showed acid-fast bacillus positivity on peritoneal tissue. The most common finding on peritoneoscopy was tubercles with adhesions (n = 14, 50%), followed by tubercles only (n = 12, 42.9%). Xpert® MTB/RIF assay was positive in 17 (60.7%) patients with a sensitivity of 60.71%, specificity of 100%, and an accuracy of 69.44%. Two patients expressed rifampicin resistance.

Conclusion

Xpert® MTB/RIF assay on peritoneal tissue has fair sensitivity and excellent specificity. The multidrug resistance and the ability to provide results rapidly make it clinically useful.

Abdominal tuberculosis with a Pseudo-Sister Mary Joseph nodule mimicking peritoneal carcinomatosis

A 46-year-old woman presented in severe abdominal pain on a background of 3 months of weight loss and intermittent vomiting. She had visited East Africa 6 months prior but reported no unwell contacts. On examination, she had generalised abdominal tenderness, distension and a painful paraumbilical swelling. CT scanning confirmed small bowel obstruction and revealed widespread peritoneal nodules, lymphadenopathy, ascites and a soft tissue paraumbilical mass. CA-125 tumour marker was elevated. However, transvaginal ultrasound scanning showed normal-appearing ovaries. She underwent a diagnostic laparoscopy for ascitic fluid analysis and biopsy of omental and peritoneal nodules, which revealed a lymphocytic exudate and caseating granulomas, respectively. Interferon-γ release assay and repeated stains for acid-fast bacilli were negative. She was commenced on antituberculous chemotherapy for a presumed diagnosis of abdominal tuberculosis. Positive culture results 2 weeks later confirmed Mycobacterium tuberculosis infection. The patient experienced a complete resolution of symptoms within 6 weeks of treatment.

Sonography to Rule Out Tuberculosis in Sub-Saharan Africa: A Prospective Observational Study

Background

Patients with suspected tuberculosis are often overtreated with antituberculosis drugs. We evaluated the diagnostic value of the focused assessment with sonography for HIV-associated tuberculosis (FASH) in rural Tanzania.

Methods

In a prospective cohort study, the frequency of FASH signs was compared between patients with confirmed tuberculosis and those without tuberculosis. Clinical and laboratory examination, chest x-ray, Xpert MTB/RIF assay, and culture from sputum, sterile body fluids, lymph node aspirates, and Xpert MTB/RIF urine assay was done.

Results

Of 191 analyzed patients with a 6-month follow-up, 52.4% tested positive for human immunodeficiency virus, 21.5% had clinically suspected pulmonary tuberculosis, 3.7% had extrapulmonary tuberculosis, and 74.9% had extrapulmonary and pulmonary tuberculosis. Tuberculosis was microbiologically confirmed in 57.6%, probable in 13.1%, and excluded in 29.3%. Ten of eleven patients with splenic or hepatic hypoechogenic lesions had confirmed tuberculosis. In a univariate model, abdominal lymphadenopathy was significantly associated with confirmed tuberculosis. Pleural- and pericardial effusion, ascites, and thickened ileum wall lacked significant association. In a multiple regression model, abnormal chest x-ray (odds ratio [OR] = 6.19; 95% confidence interval [CI], 1.96–19.6; P < .002), ≥1 FASH-sign (OR = 3.33; 95% CI, 1.21–9.12; P = .019), and body temperature (OR = 2.48; 95% CI, 1.52–5.03; P = .001 per °C increase) remained associated with tuberculosis. A combination of ≥1 FASH sign, abnormal chest x-ray, and temperature ≥37.5°C had 99.1% sensitivity (95% CI, 94.9–99.9), 35.2% specificity (95% CI, 22.7–49.4), and a positive and negative predictive value of 75.2% (95% CI, 71.3–78.7) and 95.0% (95% CI, 72.3–99.3).

Conclusions

The absence of FASH signs combined with a normal chest x-ray and body temperature <37.5°C might exclude tuberculosis.

Proportions of interferon-γ-producing ascites lymphocytes in response to mycobacterial antigens: A help for early diagnosis of peritoneal tuberculosis in a low TB incidence country

Background

Peritoneal tuberculosis (TB) remains difficult to diagnose because of its non-specific clinical features and the lack of efficient microbiological tests. As delayed diagnosis is associated with high mortality rates, new diagnostic tools are needed.

Methods and findings

We investigated for 24 patients prospectively enrolled with a possible diagnosis of peritoneal TB, the diagnostic value of the analysis of IFN-γ production by peritoneal fluid lymphocytes in response to a short in vitro stimulation with mycobacterial antigens. The patients were classified in two groups: non-TB and confirmed or highly probable TB. Diagnosis of TB was based on microbiological and histopathological criteria and/or a favorable response to anti-TB treatment. The IFN-γ production by peritoneal CD4⁺ T lymphocytes was analyzed by flow cytometry after an overnight in vitro stimulation with three different mycobacterial antigens, purified protein derivative (PPD), heparin-binding haemagglutinin (HBHA) or early-secreted-antigen-target-6 (ESAT-6). The percentages of PPD-, HBHA- or ESAT-6-induced IFN-γ-producing peritoneal fluid CD4⁺ T lymphocytes were higher in the TB group than in the non-TB group (p = 0.0007, p = 0.0004, and p = 0.0002 respectively). Based on cut-off values determined by ROC curve analysis of the results from TB and highly probable TB compared to those of non-TB patients, the sensitivity of these three tests was 100% with a specificity of 92%.

Conclusions

The analysis of mycobacterial-induced IFN-γ production by peritoneal lymphocytes is a promising tool to reliably and rapidly diagnose peritoneal TB. Further studies should be performed on larger cohorts of patients in high-TB-incidence countries to confirm the clinical value of this new diagnostic approach for peritoneal TB.

Fitz-Hugh-Curtis syndrome associated with tuberculous salpingitis and peritonitis: a case presentation and review of literature

Background

Fitz-Hugh-Curtis syndrome or acute perihepatitis is considered a rare complication of pelvic inflammatory disease, mostly associated with chlamydial or gonococcal salpingitis.

Peritoneal tuberculosis is a rare site of extra-pulmonary infection caused by Mycobacterium tuberculosis. Infection usually occurs after reactivation of latent tuberculous foci in the peritoneum and more seldom after contiguous spread from tuberculous salpingitis.

Case presentation

We describe a case of a 21-year old female of Somalian origin diagnosed with Fitz-Hugh Curtis syndrome associated with tuberculous salpingitis and peritonitis, presenting with new onset ascites.

Acid fast stained smear and polymerase chain reaction for Mycobacterium tuberculosis on ascitic fluid, endocervical culture and tuberculin skin test were all negative. Eventually, the diagnosis was made laparoscopically, showing multiple peritoneal white nodules and perihepatic “violin string” fibrinous strands.

Conclusions

To our knowledge, this is the first case where Fitz-Hugh-Curtis syndrome is associated with both peritoneal and genital tuberculosis and where ascites was the primary clinical finding. Female genital tuberculosis has only rarely been associated with Fitz-Hugh-Curtis syndrome and all cases presented with chronic abdominal pain and/or infertility. Ascites and peritoneal involvement was not present in any case. Moreover, most patients with Fitz-Hugh-Curtis syndrome show no evidence of generalized intra-abdominal infection and only occasionally have concomitant ascites.

Review article: the diagnostic approach and current management of chylous ascites

BACKGROUND

Chylous ascites is rare, accounting for less than 1% of cases. An appropriate and stepwise approach to its diagnosis and management is of key importance.

AIM

To review the current diagnostic approach and management of chylous ascites.

METHODS

A literature search was conducted using PubMed using the key words 'chylous', 'ascites', 'cirrhosis', 'pathophysiology', 'nutritional therapy', 'paracentesis", "transjugular intrahepatic portosystemic shunt" and "TIPSS'. Only articles in English were included.

RESULTS

Chylous ascites is caused by the traumatic or obstructive disruption of the lymphatic system that leads to extravasation of thoracic or intestinal lymph into the abdominal space and the accumulation of a milky fluid rich in triglycerides. The most common causes are malignancy, cirrhosis and trauma after abdominal surgery. This condition can lead to chyle depletion, which results in nutritional, immunologic and metabolic deficiencies. An ascitic triglyceride concentration above 200 mg/dL is consistent with chylous ascites. Treatment is based on management of the underlying cause and nutritional support.

CONCLUSIONS

Chylous ascites is mostly due to malignancy and cirrhosis in adults, and congenital lymphatic disorders in children. Treatment with nutritional optimization and management of the underlying etiology are the cornerstones of therapy. When conservative measures fail, other interventions such as octreotide/somatostatin analogues, surgical ligation, embolization and transjugular intrahepatic portosystemic shunt in patients with cirrhosis can be considered.

Cattle naturally infected by Eurytrema coelomaticum: Relation between adenosine deaminase activity and zinc levels

The enzyme adenosine deaminase (ADA) is critical for modulating the immune system, and in the presence of zinc, its activity is catalyzed. The aim of this study was to evaluate the ADA activity in pancreas of cattle naturally infected by Eurytrema coelomaticum in relation to the results of zinc levels, pathological findings and parasite load. For this study 51 slaughtered cattle were used. The animals were divided into two groups: Group A consisting of animals naturally infected by E. coelomaticum (n=33) and Group B of uninfected animals (n=18). Blood and pancreas were collected of each animal for analysis of zinc and ADA, respectively. Infected cattle showed a reduction on seric levels of zinc, and decreased ADA activity in the pancreas (P>0.05). A positive correlation between zinc levels and ADA activity was observed. Thus, high parasite load and severity of histopathologic lesions affect the ADA activity in pancreas, as well as the zinc levels in serum of infected animals (negative correlation between these variables). Therefore, we can conclude that cattle infected by E. coelomaticum have low ADA activity in pancreas, which can be directly related to zinc reduction, responsible for ADA activation and catalyzes.