How can gastro-intestinal tuberculosis diagnosis be improved? A prospective cohort study

Abstract

Background: Gastrointestinal tuberculosis (TB) is diagnostically challenging; therefore, many cases are treated presumptively. We aimed to describe features and outcomes of gastrointestinal TB, determine whether a clinical algorithm could distinguish TB from non-TB diagnoses, and calculate accuracy of diagnostic tests. Methods: We conducted a prospective cohort study of hospitalized patients in Kota Kinabalu, Malaysia, with suspected gastrointestinal TB. We recorded clinical and laboratory characteristics and outcomes. Tissue samples were submitted for histology, microscopy, culture and GeneXpert MTB/RIF®. Patients were followed for up to 2 years. Results: Among 88 patients with suspected gastrointestinal TB, 69 were included in analyses; 52 (75%) had a final diagnosis of gastrointestinal TB; 17 had a non-TB diagnosis. People with TB were younger (42.7 versus 61.5 years, p = 0.01) and more likely to have weight loss (91% versus 64%, p = 0.03). An algorithm using age < 44, weight loss, cough, fever, no vomiting, albumin > 26 g/L, platelets > 340 × 10 9 /L and immunocompromise had good specificity (96.2%) in predicting TB, but very poor sensitivity (16.0%). GeneXpert® performed very well on gastrointestinal biopsies (sensitivity 95.7% versus 35.0% for culture against a gold standard composite case definition of confirmed TB). Most patients (79%) successfully completed treatment and no treatment failure occurred, however adverse events (21%) and mortality (13%) among TB cases were high. We found no evidence that 6 months of treatment was inferior to longer courses. Conclusions: The prospective design provides important insights for clinicians managing gastrointestinal TB. We recommend wider implementation of high-performing diagnostic tests such as GeneXpert® on extra-pulmonary samples.

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

“…[ 92 ] The presence of distinctive granulomas in the intestinal biopsy can help establish the diagnosis of GITB with a sensitivity, specificity, positive predictive value and negative predictive value of 28-58%, 69-100%, 64-100% and 41-65%, respectively [ Figure 5 ]. [ 55 94 95 96 97 ]…”

“…[ 50 53 98 ] The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detection of AFB on biopsy smear are 6-31%, 100%, 100% and 57%, respectively [ Figure 6 ]. [ 97 99 100 ] Similarly, the sensitivity, specificity, PPV and NPV of AFB culture on biopsy are 9-35%, 100%, 100% and 38-63%, respectively [ Figure 7 ]. [ 55 94 97 ] PCR on intestinal biopsy shows a high rate of positivity between 50 and 95%.…”

Genomic epidemiology of tuberculosis in eastern Malaysia: insights for strengthening public health responses

“…Instead, the data suggest wide transmission networks in communities of diverse circulating TB strains. In addition to incomplete sampling, cases missing from this analysis include smear negative and extrapulmonary cases (in whom sample collection is challenging and diagnosis is often on clinical grounds) [ 35 ] and undiagnosed TB cases. Incomplete ascertainment of cases is recognized as a problem in all high-TB-burden settings.…”

The diagnostic challenge of abdominal tuberculosis in nonendemic countries: A case series from a tertiary hospital in Germany

“…This is in concordance with investigators studying common clinical presentations in ATB, 1 whereas other literature resources describe a different spectrum of clinical features, such as weakness, abdominal mass, abdominal distension, and night sweats 13 . Several laboratory markers, such as serum albumin <26 g/L (norm: 35–55 g/L) and platelets >340 × 10 9 /L (norm: 150 × 10 9 /L–450 × 10 9 /L) have been proposed to be useful in prediction models of ATB but still have a very poor sensitivity 14 . These parameters were all normal in our patients, and none of them complained about night sweats.…”