Diagnostic performance of interferon-γ release assay for lymph node tuberculosis

Laryngeal tuberculosis in the early 21st century. Literature review of clinical, diagnostic and therapeutic data, according to SWiM guidelines

OBJECTIVES

Review of the scientific medical literature dedicated to clinical data, diagnosis and treatment for laryngeal tuberculosis published since the turn of the 21st century.

MATERIAL AND METHODS

Search of the Medline, Cochrane and Embase databases for the period 2000-2022. Selection of cohorts and case reports documenting clinical data, diagnosis and treatment for laryngeal tuberculosis.

RESULTS

In total, 119 articles were analyzed. Immunodepression, HIV infection, history of lung tuberculosis, general symptoms suggesting tuberculosis, smoking and associated laryngeal cancer were noted in 18%, 3%, 20% and 41% of cases, respectively. No pathognomonic symptoms or signs emerged. Voice impairment, of various types and severity, isolated and/or associated with other signs, was the most frequent laryngeal symptom, in 86% of cases. All laryngeal sites were involved, with numerous and various associations. Impaired laryngeal motion and tracheotomy were noted in 6% and 1% of cases, respectively. Time to diagnosis varied from less than 1month to 36months, for a median 3months, in case reports. Laryngeal tuberculosis was diagnosed bacteriologically with certainty in 28% of cases while diagnosis was based on indirect criteria and/or involvement of another site in the other 72%, with lung involvement in 54%. Treatment duration ranged from 6 to 24months (median, 6months), using 3 to 5 (median: 4) antitubercular antibiotics, with 4 used in 80% of cohorts and 77% of case reports. Overall rates of cure, death, treatment resistance, adverse events, and laryngeal sequelae were 99%, 0.5%, 0.5%, 6% and 5%, respectively.

CONCLUSION

The clinical presentation and diagnostic difficulty in laryngeal tuberculosis did not change since the end of the 20th century. Quadritherapy is highly effective, with a low resistance rate and few adverse effects or laryngeal sequelae.

TB Antigen-Stimulated CXCR3 Ligand Assay for Diagnosis of Tuberculous Lymphadenitis

The diagnosis of tuberculous lymphadenitis (TB-LAP) is challenging. We evaluated the role of blood CXC chemokine receptor 3 (CXCR3) ligands in its diagnosis. A total of 65 lymphadenopathy patients were enrolled and lymph node sampling was performed. We also recruited 113 control subjects, consisting of 27 with positive results and 86 with negative results, in the interferon (IFN)-γ release assay (IGRA). In all study subjects, whole-blood samples were collected using the IGRA methodology. After incubation, plasma levels of IFN-γ and two CXCR3 ligands, IFN-inducible T-cell a chemoattractant (I-TAC) and monokine induced by IFN-γ (MIG), were measured using immunoassay. Fifty-three TB-LAP patients were enrolled. TB antigen-stimulated IFN-γ, I-TAC, and MIG levels were all significantly higher in the TB-LAP patients than in the controls and non-TB-LAP patients. The levels of I-TAC and MIG, but not IFN-γ, showed significant differences between the TB-LAP patients and IGRA-positive controls. Area under the receiver operating characteristic curves (AUROCs) of IFN-γ, I-TAC, and MIG were 0.955, 0.958, and 0.959, respectively, for differentiating TB-LAP from control group, and were 0.912, 0.956, and 0.936, respectively, for differentiating TB-LAP from non-TB-LAP. In conclusion, the TB antigen-stimulated MIG and I-TAC could be useful biomarkers in the diagnosis of TB-LAP.

Appearance and morphologic features of laryngeal tuberculosis using laryngoscopy: A retrospective cross-sectional study

Laryngeal tuberculosis (LTB) is highly contagious and can cause permanent laryngeal damage. Therefore, correctly identifying laryngoscopic LTB lesion locations, sizes, and morphologic features are essential for LTB diagnoses. This study aimed to explore the appearance and morphologic features of LTB and correlated these features with clinical symptoms.We retrospectively analysed 39 LTB patients in our hospital between January 2013 and December 2019. Medical records, including clinical presentation, lesion appearance (locations, sizes, and morphology), complementary examination results, and histopathologic features were summarized and analysed.In this patient cohort, dysphonia and sore throat were the two most common clinical symptoms. In LTB patients with extensive lesions, ulcerative lesions were most common, and the proportion of cases with concurrent pulmonary tuberculosis (86.4%, P = .033) infection was higher, as were the positive rates of sputum smears (72.7%, P = .011) and cultures (86.4%, P = .002) than patients without concurrent pulmonary TB and with more localized and exophytic lesions. The histopathologic features of LTB-related ulcerative lesions included fewer granulomas and more areas with caseous necrosis. These lesions were more likely to have acid-fast bacilli detected with a Ziehl-Neelsen stain than exophytic lesions that rarely showed detectable bacilli.A complete knowledge regarding the visual and morphologic features of LTB on laryngoscopy is needed for the early detection and diagnosis of LTB. Our study revealed the lesion sites, sizes, and morphologic features of LTB. These parameters were also correlated with patient clinical symptoms. Future studies are needed to support and expand the results of this retrospective study.

Interferon gamma release assays for Diagnostic Evaluation of Active tuberculosis (IDEA): test accuracy study and economic evaluation

BACKGROUND

Interferon gamma release assays (IGRAs) are blood tests recommended for the diagnosis of tuberculosis (TB) infection. There is currently uncertainty about the role and clinical utility of IGRAs in the diagnostic workup of suspected active TB in routine NHS clinical practice.

OBJECTIVES

To compare the diagnostic accuracy and cost-effectiveness of T-SPOT.TB ^® (Oxford Immunotec, Abingdon, UK) and QuantiFERON^® TB GOLD In-Tube (Cellestis, Carnegie, VIC, Australia) for diagnosis of suspected active TB and to estimate the diagnostic accuracy of second-generation IGRAs.

DESIGN

Prospective within-patient comparative diagnostic accuracy study.

SETTING

Secondary care.

PARTICIPANTS

Adults (aged ≥ 16 years) presenting as inpatients or outpatients at 12 NHS hospital trusts in London, Slough, Oxford, Leicester and Birmingham with suspected active TB.

INTERVENTIONS

The index tests [T-SPOT.TB and QuantiFERON GOLD In-Tube (QFT-GIT)] and new enzyme-linked immunospot assays utilising novel Mycobacterium tuberculosis antigens (Rv3615c, Rv2654, Rv3879c and Rv3873) were verified against a composite reference standard applied by a panel of clinical experts blinded to IGRA results.

MAIN OUTCOME MEASURES

Sensitivity, specificity, predictive values and likelihood ratios were calculated to determine diagnostic accuracy. A decision tree model was developed to calculate the incremental costs and incremental health utilities [quality-adjusted life-years (QALYs)] of changing from current practice to using an IGRA as an initial rule-out test.

RESULTS

A total of 363 patients had active TB (culture-confirmed and highly probable TB cases), 439 had no active TB and 43 had an indeterminate final diagnosis. Comparing T-SPOT.TB and QFT-GIT, the sensitivities [95% confidence interval (CI)] were 82.3% (95% CI 77.7% to 85.9%) and 67.3% (95% CI 62.1% to 72.2%), respectively, whereas specificities were 82.6% (95% CI 78.6% to 86.1%) and 80.4% (95% CI 76.1% to 84.1%), respectively. T-SPOT.TB was more sensitive than QFT-GIT (relative sensitivity 1.22, 95% CI 1.14 to 1.31; p < 0.001), but the specificities were similar (relative specificity 1.02, 95% CI 0.97 to 1.08; p = 0.3). For both IGRAs the sensitivity was lower and the specificity was higher for human immunodeficiency virus (HIV)-positive than for HIV-negative patients. The most promising novel antigen was Rv3615c. The added value of Rv3615c to T-SPOT.TB was a 9% (95% CI 5% to 12%) relative increase in sensitivity at the expense of specificity, which had a relative decrease of 7% (95% CI 4% to 10%). The use of current IGRA tests for ruling out active TB is unlikely to be considered cost-effective if a QALY was valued at £20,000 or £30,000. For T-SPOT.TB, the probability of being cost-effective for a willingness to pay of £20,000/QALY was 26% and 21%, when patients with indeterminate test results were excluded or included, respectively. In comparison, the QFT-GIT probabilities were 8% and 6%. Although the use of IGRAs is cost saving, the health detriment is large owing to delay in diagnosing active TB, leading to prolonged illness. There was substantial between-patient variation in the tests used in the diagnostic pathway.

LIMITATIONS

The recruitment target for the HIV co-infected population was not achieved.

CONCLUSIONS

Although T-SPOT.TB was more sensitive than QFT-GIT for the diagnosis of active TB, the tests are insufficiently sensitive for ruling out active TB in routine clinical practice in the UK. Novel assays offer some promise.

FUTURE WORK

The novel assays require evaluation in distinct clinical settings and in immunosuppressed patient groups.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London, London, UK.

Left-sided portal hypertension caused by peripancreatic lymph node tuberculosis misdiagnosed as pancreatic cancer: a case report and literature review

Background

Left-sided portal hypertension (LSPH) is an extremely rare clinical syndrome, and it is the only form of curable portal hypertension. It is primarily caused by pancreatic disease, and is associated with complications that cause spleen vein compression. Specific symptoms are often lacking, rendering it difficult to diagnose. Splenectomy is the main treatment for cases complicated by variceal bleeding, and the effects of treatment primarily depend on the condition of the primary disease.

Case presentation

The patient was a 29-year-old woman who was admitted to the hospital for repeated hematemesis and black stool. She had been misdiagnosed with pancreatic cancer 7 years prior. Combined imaging and endoscopic examination indicated varicose gastric fundus veins, a pancreatic mass, and enlarged peripancreatic lymph nodes. Laboratory investigations revealed reduced erythrocyte, platelet, and leukocyte counts, the interferon gamma release assay was positive, and liver function was normal. Abdominal exploration, splenectomy, varicose vein dissection, and lesion resection were performed via laparotomy. Postoperative biopsy analysis confirmed the diagnosis of lymph node tuberculosis. Based on the above-described factors, LSPH caused by peripancreatic lymph node tuberculosis was a diagnosed.

Conclusions

Herein we describe the first reported case of LSPH caused by peripancreatic lymph node tuberculosis. When left portal hypertension occurs simultaneously, peripancreatic lymph node tuberculosis is often misdiagnosed as pancreatic cancer. Further studies are necessary to develop a more favorable diagnostic method for pancreas masses and more advantageous therapy for LSPH, especially in cases caused by mechanical compression.

Cystic form of cervical lymphadenopathy. Guidelines of the French Society of Otorhinolaryngology - Head and Neck Surgery (SFORL). Part 1: Diagnostic procedures for lymphadenopathy in case of cervical mass with cystic aspect

OBJECTIVES

The authors present the guidelines of the French Society of Otorhinolaryngology - Head and Neck Surgery Society on diagnostic procedures for lymphadenopathy in case of a cervical mass with cystic aspect.

METHODS

A multidisciplinary work-group was entrusted with a review of the scientific literature on the topic. Guidelines were drawn up, then read over by an editorial group independent of the work-group, and the final version was drawn up. Guidelines were graded as A, B, C or expert opinion, by decreasing level of evidence.

RESULTS

In adults presenting a cystic cervical mass, it is recommended to suspect cervical lymphadenopathy: in order of decreasing frequency, cystic metastasis of head and neck squamous cell carcinoma, of undifferentiated nasopharyngeal carcinoma, and of thyroid papillary carcinoma (Grade C). On discovery of a cystic cervical mass on ultrasound, architectural elements indicating a lymph node and a thyroid nodule with signs of malignancy should be screened for, especially if the mass is located in levels III, IV or VI (Grade A). Malignant lymphadenopathy should be suspected in case of cervical mass with cystic component on CT (Grade B), but benign or malignant status cannot be diagnosed only on radiological data (CT or MRI) (Grade A), and 18-FDG PET-CT should be performed, particularly in case of inconclusive ultrasound-guided fine needle aspiration biopsy (Grade C).

Use of Interferon-γ release assay for the diagnosis of female genital tuberculosis in Northwest China

BACKGROUND

Female genital tuberculosis (FGTB) is one of the major causes of infertility. However, nonspecific manifestations and the lack of easy access to gold-standard diagnostic test render a diagnostic difficult for FGTB. The objective of this study was to determine T-SPOT.TB (an interferon-γ release assay, IGRA) performance in patients with FGTB.

METHODS

A total of 213 female patients with validated T-SPOT.TB results were recruited in this retrospective study. Among which, 103 were confirmed FGTB, and 110 were excluded from tuberculosis (control). Of the confirmed FGTB patients, 52 were confirmed by microbiologically/histopathologically examination, while the remaining 51 were clinically confirmed (successfully responsive to anti-tuberculosis treatment). T-SPOT.TB test was performed in both FGTB and control group during the diagnostic procedure.

RESULTS

The overall sensitivity and specificity of T-SPOT.TB were 86.41% and 75.45% respectively. Sensitivity of T-SPOT.TB was significantly higher when compared with conventional tuberculosis diagnostic tests. Moreover, T-SPOT.TB test using pelvic effusion (PE) showed higher sensitivity than using corresponding peripheral blood (PB) (94.44% vs 72.22%, P < 0.001). Mean value of spot forming cells (SFCs) of T-SPOT.TB using PE was significantly higher than that of PB in FGTB group (193 (IQR 105-280) SFCs/2.5 × 10⁵ PEMCs vs 71 (IQR 36-107) SFCs/2.5 × 10⁵ PBMCs, P = 0.01), while this was not detected in control group (11 (IQR 0-22) SFCs/2.5 × 10⁵ PEMCs vs 9 (IQR 0-18) SFCs/2.5 × 10⁵ PBMCs, P = 0.77).

CONCLUSION

These results demonstrated that T-SPOT.TB, especially PE T-SPOT.TB, is an useful adjunct in FGTB diagnosis.

Empirical treatment with non-anti-tuberculosis antibiotics decreased microbiological detection in cervical tuberculous lymphadenitis

Diagnosis of cervical tuberculous lymphadenitis (CTL), the most commonly occurring form of extrapulmonary tuberculosis, remains as a challenge in clinic. Detection of the presence of Mycobacterium tuberculosis (Mtb) in fine needle aspiration cytology (FNAC) samples is one golden criterion to confirm the CTL diagnosis. Due to the non-specific clinical presentation, CTL might be confused with other lymph node enlargement diseases; therefore empirical treatment with non-anti-TB antibiotics is often initially administered. However, it is still unclear whether this diagnostic antibiotic treatment affects the positivity of Mtb detection in FNAC. The demographics and clinical characteristics of 732 lymph node enlargement patients who had underwent FNAC were retrospectively analyzed and 605 (82.65%) of them were diagnosed as CTL. A total of 279 CTL cases (279/605, 46.11%) with completion of three Mtb tests (AFB, NAAT, and Mtb culture) in FNAC samples were selected for analyzing the effect of empirical antibiotic treatment on the positivity of Mtb tests. Compared to CTL patients without antibiotic treatment prior to FNAC, patients received empirical non anti-TB treatment had significantly lower positivity for acid fast bacilli staining (adjusted OR 0.11, 95% CI 0.06-0.21), nucleic acid amplification test (NAAT) (adjusted OR 0.38, 95% CI 0.21-0.71), and Mtb culture (adjusted OR 0.11, 95% CI 0.06-0.19). In conclusion, this study demonstrated that empirical non anti-TB antibiotic treatment reduced the opportunity to confirm CTL by microbiological analysis. Patients with cervical lymph node enlargement should undergo FNAC for Mtb tests prior to initiation of empirical non anti-TB treatment.

The risk factor of false-negative and false-positive for T-SPOT.TB in active tuberculosis

OBJECTIVES

T-SPOT.TB is a promising diagnosis tool to identify both pulmonary tuberculosis and extrapulmonary tuberculosis, as well as latent tuberculosis; however, the factors that affect the results of T-SPOT.TB remains unclear. In this study, we aim to figure out the risk factor of T-SPOT.TB for active TB.

METHODS

A total of 349 patients were recruited between January 1st, 2016 and January 22st, 2017 at Renmin Hospital of Wuhan University, including 98 subjects with TB and 251 subjects with non-TB disease, and received T-SPOT.TB (Oxford Immunotec Ltd). Statistics were analyzed by SPSS 19.0 using logistic regression.

RESULTS

The overall specificity and sensitivity of the T-SPOT.TB was 92.83% (233/251; 95%CI 0.8872-0.9557) and 83.67% (82/98; 95%CI 0.7454-0.9010), respectively. Patients with tuberculous meningitis were more likely to have false-negative results (OR 17.4, 95%CI 3.068-98.671; P<.001) while patients with cured TB tended to induce false-positive results (OR 30.297; 95%CI 7.069-129.849; P<.001). The results were not affected by sex, age, onset time, smoke, alcohol, treatment, allergic history, co-morbidity, TB (exclude tuberculous meningitis) (P>.05).

CONCLUSION

Tuberculous meningitis was a risk factor of false-negative for T-SPOT.TB, while cured TB was a risk factor of false-positive.

Performance of interferon-γ release assay in the diagnosis of tuberculous lymphadenitis: a meta-analysis

Background

The diagnostic values of interferon-gamma release assays (IGRA) in tuberculosis (TB) vary a lot with different site of infections, with especially higher sensitivities in chronic forms of TB such as tuberculosis of the lymph node. We conducted a meta-analysis to comprehensively evaluate the overall accuracy of diagnostic IGRA for tuberculous lymphadenitis.

Methods

Pubmed, Web of Science, EMBASE, Wanfang and CNKI databases up to February 17, 2017 were searched to identify published studies. The study quality was evaluated using the QUADAS-2 checklist. The pooled estimates of diagnostic parameters were generated using a bivariate random-effects model and summary receiver operating characteristic (SROC) curves were used to summarize global performance.

Results

A total of ten qualified studies, performed in Korea or China, including 1,084 patients, were enrolled in this meta-analysis. The pooled estimates of diagnostic accuracy were as follows: sensitivity, 0.89 (95% CI [0.85–0.92]); specificity, 0.81 (95% CI [0.77–0.83]); positive likelihood ratio (PLR), 4.25 (95% CI [2.79–6.47]); negative likelihood ratio (NLR), 0.16 (95% CI [0.12–0.22]); and area under the curve (AUC) was 0.93. According to subgroup analyses, studies conducted using QuantiFERON-TB, in Korean population and focusing on cervical lymphadenitis exhibited relative higher specificity while lower sensitivity. No evidence of publication bias was identified.

Conclusions

IGRA exhibits high diagnostic accuracy in tuberculous lymphadenitis. The diagnostic value of IGRA differed by different IGRA methods, ethnicity and lymphadenitis location. Our conclusion may be more applicable to population from TB prevalent areas.