Integrating systemic immune-inflammation index, fibrinogen, and T-SPOT.TB for precision distinction of active pulmonary tuberculosis in the era of mycobacterial disease research.

Background: The clinical challenge of differentiating suspected tuberculosis with positive T-SPOT.TB results persist. This study aims to investigate the utility of the Systemic Immune-Inflammation Index (SII), Fibrinogen, and T-SPOT.TB in distinguishing between active pulmonary tuberculosis (PTB) and non-tuberculous lung diseases. Methods: A retrospective analysis included 1,327 cases of active PTB with positive T-SPOT.TB results and 703 cases of non-tuberculous lung diseases from May 2016 to December 2020 at Meizhou People's Hospital. These were designated as the case group and the control group, respectively. The detection indicators of T-SPOT.TB: Early Secreted Antigenic Target 6 (ESAT-6), Culture Filtrate Protein 10 (CFP-10), as well as SII and Fibrinogen levels-were compared and analyzed for association and joint diagnostic value between the two groups. Results: The case group showed higher values of ESAT-6, CFP-10, SII, and Fibrinogen compared to the control group (all p < 0.001). In the case group, SII and Fibrinogen did not correlate with ESAT-6 and CFP-10 (∣rs∣ all < 0.3) but were positively correlated with C-reactive protein (CRP; rs all > 0.3). SII and Fibrinogen values in smear-positive pulmonary tuberculosis were higher than in smear-negative cases (all p < 0.05). The optimal diagnostic thresholds for ESAT-6, CFP-10, SII, and Fibrinogen in differentiating between active PTB and non-tuberculous lung diseases were 21.50 SFCs/106 PBMC, 22.50 SFCs/106 PBMC, 2128.32, and 5.02 g/L, respectively. Regression logistic analysis showed that ESAT-6 < 21.5 (OR: 1.637, 95% CI: 1.311-2.043, p < 0.001), CFP-10 < 22.5 (OR: 3.918, 95% CI: 3.138-4.892, p = 0.025), SII < 2128.32 (OR: 0.763, 95% CI: 0.603-0.967, p < 0.001), and FIB < 5.02 (OR: 2.287, 95% CI: 1.865-2.806, p < 0.001) were independent risk factors for active PTB. The specificity for ESAT-6 + CFP-10, ESAT-6 + CFP-10 + SII, ESAT-6 + CFP-10 + FIB, and ESAT-6 + CFP-10 + SII + FIB was 82.5%, 83.2%, 95.8%, and 80.1%, respectively, while sensitivity was 52.6%, 53.0%, 55.8%, and 44.7%, and positive predictive values were 85.0%, 85.6%, 84.1%, and 89.6%, respectively. Conclusion: SII and Fibrinogen are positively correlated with the degree of tuberculosis inflammation and the bacterial load of Mycobacterium tuberculosis. The combined detection of SII, Fibrinogen, and T-SPOT.TB is significant in distinguishing between active PTB with positive T-SPOT.TB results and non-tuberculous lung diseases.

Interleukin-17A Inhibitors in Patients with Psoriasis and Tuberculosis Infection: A 2-Year Prospective Study on Safety Without Preventive Treatment.

INTRODUCTION: The necessity for tuberculosis preventive treatment (TPT) and routine T-SPOT.TB monitoring in patients with psoriasis and tuberculosis infection (TBI) undergoing interleukin (IL)-17A inhibitor therapy remains uncertain. This study aims to evaluate the long-term safety of IL-17A inhibitors administered without TPT and analyze changes in T-SPOT.TB among these patients. It also identifies risk factors for TBI in patients with psoriasis. METHODS: This single-center prospective study enrolled adult patients with plaque psoriasis and TBI receiving IL-17A inhibitors. TBI was defined as positive T-SPOT.TB results (≥ 6 spots) without symptoms or evidence of active tuberculosis (ATB). TPT administration was based on contraindications, tuberculosis risk factors, and patient preferences. The primary endpoint was the incidence of ATB over 2 years. Secondary outcomes included T-SPOT.TB changes and TBI risk factors. RESULTS: Of the 129 patients with psoriasis and TBI enrolled in the study, 97 (75.2%) did not receive TPT, while 32 (24.8%) did. Among them, 109 patients (84.5%) completed the 2-year follow-up. During the 235 person-years of observation, no ATB cases were identified. Median T-SPOT.TB values showed no significant changes from baseline to year 2 in both the non-TPT (20 vs. 17 spots, p = 0.975) and TPT groups (55 vs. 58 spots, p = 0.830). T-SPOT.TB reversed in 14 patients (12.8%), mostly in the non-TPT group. Moreover, for TBI risk factor analysis, a cohort of 212 patients with psoriasis with negative baseline T-SPOT.TB was evaluated, revealing a TBI prevalence of 37.8%. Logistic regression analysis highlighted age ≥ 45 years (odds ratio [OR] 2.44, 95% confidence interval [CI] 1.50-3.99, p < 0.001) and body mass index (BMI) < 24.0 kg/m2 (OR 2.12, 95% CI 1.27-3.54, p = 0.004) as independent risk factors for TBI. CONCLUSION: IL-17A inhibitors do not appear to reactivate tuberculosis in patients with psoriasis and TBI, potentially reducing the need for routine TBI screening and preventive treatment. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2100045823.

Diagnostic efficacy of optimized T-SPOT.TB in differentiating spinal tu-berculosis from other spinal infection / 中国感染控制杂志

Objective To explore the efficacy of T-cell spot test of tuberculosis infection(T-SPOT.TB)in the differential diagnosis of spinal tuberculosis(STB),and optimize diagnostic efficacy through the optimal cut-off value of receiver operating characteristic(ROC)curve.Methods Clinical data of patients with spinal infection in a hospi-tal from January 2010 to May 2019 were collected,including preoperative T-SPOT.TB test results,white blood cell count,C-reactive protein,erythrocyte sedimentation rate,procalcitonin,and tuberculosis antibodies,etal.Clinical diagnosis was conducted based on diagnostic criteria.The sensitivity and specificity of T-SPOT.TB in preoperative diagnosis of STB and other spinal infection was analyzed,and the diagnostic efficacy of the optimized T-SPOT.TB indicators was evaluated.Results A total of 132 patients were included in this study,out of whom 78 patients(59.09％)were diagnosed with STB,and 54(40.91％)were diagnosed with non-tuberculosis(non-TB)spinal in-fection.The sensitivity and specificity of T-SPOT.TB in differential diagnosis of STB were 67.68％and 66.67％,respectively.Univariate logistic regression analysis showed that compared with non-TB spinal infection,the OR va-lue of T-SPOT.TB test in diagnosing STB was 4.188(95％CI:1.847-9.974,P＜0.001).The optimized T-SPOT.TB evaluation index through ROC curve to determine the optimal cut-off values of ESAT-6,CFP-10,and CFP-10+ESAT-6 for differential diagnosis of STB and non-TB spinal infection were 12.5,19.5,and 36,respec-tively,and area under curve(AUC)values were 0.765 6,0.741 5,and 0.778 6,respectively,all with good diag-nostic efficacy.CFP-10+ESAT-6 had the highest AUC.CFP-10+ESAT-6 specific spot count had higher efficacy in the diagnosis of STB,with a diagnostic accuracy of 75.56％,higher than 67.42％of pre-optimized T-SPOT.TB.Conclusion T-SPOT.TB test has high diagnostic efficacy in differentiating STB from non-TB spinal infection.Posi-tivity in T-SPOT.TB test,especially with spot count of CFP-10+ESAT-6 over 36,indicates a higher likelihood of STB.

Association of Mycobacterium tuberculosis infection test results with risk factors for tuberculosis transmission.

Background: Close contacts infected with Mycobacterium tuberculosis are at high risk of tuberculosis (TB) disease and a priority for preventive treatment. Three tests measure infection: two interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST). The objective of our study was to assess the association of positive test results in contacts with infectiousness of the presumed TB source case. Methods: Contacts in a cohort study at 10 United States sites received both IGRAs (QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB (T-SPOT)) and TST. We defined test conversion as negative for all tests at baseline and positive for at least one on retest. Risk ratios (RR) and 95% confidence intervals (CI) assessed association of positive test results with increased infectiousness of the TB case-defined as acid-fast bacilli (AFB) on sputum microscopy or cavities on chest radiographs- and contact demographics. Results: Adjusted for contacts' age, nativity, sex, and race, IGRAs (QFT-GIT RR = 6.1, 95% CI 1.7-22.2; T-SPOT RR = 9.4, 95% CI 1.1-79.1), but not TST (RR = 1.7, 95% CI 0.8-3.7), were more likely to convert among contacts exposed to persons with cavitary TB disease. Conclusions: Because IGRA conversions in contacts are associated with infectiousness of the TB case, their use may improve efficiency of health department contact investigations by focusing efforts on those likely to benefit from preventive treatment in the United States.

Diagnosis of Latent Tuberculosis Infection in Hemodialysis Patients: TST versus T-SPOT.TB.

Hemodialysis (HD) patients should be screened for latent tuberculosis (TB) infection. We aimed to determine the frequency of latent TB infection in HD patients and to compare the effectiveness of the tests used. The files of 56 HD patients followed between 1 January 2021 and 1 October 2022 were retrospectively analyzed. Demographic data, the presence of the Bacillus Calmette-Guerin (BCG) vaccine, whether or not the patients had previously received treatment for TB before, the status of encountering a patient with active TB of patients over 18 years of age, without active tuberculosis and who had a T-SPOT.TB test or a Tuberculin Skin Test (TST) were obtained from the patient files. The presence of previous TB in a posterior-anterior (PA) chest X-ray was obtained by evaluating PA chest X-rays taken routinely. Of the patients, 60.7% (n = 34) were male and their mean age was 60.18 ± 14.85 years. The mean duration of dialysis was 6.43 ± 6.03 years, and 76.8% (n = 43) had 2 BCG scars. The T-SPOT.TB test was positive in 32.1% (n = 18). Only 20 patients (35.7%) had a TST and all had negative results. While the mean age of those with positive T-SPOT.TB results was higher (p = 0.003), the time taken to enter HD was shorter (p = 0.029). T-SPOT.TB test positivity was higher in the group that had encountered active TB patients (p = 0.033). However, no significant difference was found between T-SPOT.TB results according to BCG vaccine, albumin, urea and lymphocyte levels. Although T-SPOT.TB test positivity was higher in patients with a previous TB finding in a PA chest X-ray, there was no statistically significant difference (p = 0.093). The applicability of the TST in the diagnosis of latent TB infection in HD patients is difficult and it is likely to give false-negative results. The T-SPOT.TB test is not affected by the BCG vaccine and immunosuppression. Therefore, using the T-SPOT.TB test would be a more appropriate and practical approach in the diagnosis of latent TB in HD patients.

T-SPOT.TB Reactivity in Southern African Children With and Without in Utero Human Immunodeficiency Virus Exposure.

Infants who are human immunodeficiency virus (HIV)-exposed uninfected (iHEU) experience higher risk of infectious morbidity than infants HIV-unexposed uninfected (iHUU). We compared tuberculosis (TB) infection prevalence in 418 Bacillus Calmette-Guérin vaccinated sub-Saharan African iHEU and iHUU aged 9-18 months using T-SPOT.TB. Prevalence of TB infection was low and did not differ by HIV exposure status.

Latent Tuberculosis Infection and Associated Factors in Patients with Systemic Lupus Erythematosus: a Multicenter, Cross-Sectional Study.

The objectives of this study were to screen for latent tuberculosis infection (LTBI) among patients with systemic lupus erythematosus (SLE) using the T-SPOT.TB assay and to identify factors affecting the assay results. SLE patients were enrolled from 13 tertiary hospitals in eastern, central, and western China from September 2014 to March 2016 and were screened using the T-SPOT.TB assay to detect LTBI. Basic information about the subjects was collected, including gender, age, body mass index (BMI), course of disease, evidence of previous tuberculosis, Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, and the use of glucocorticoids and immunosuppressants. Univariate analysis and multivariable logistic regression were performed to identify factors affecting the results of the T-SPOT.TB assay. In all, 2,229 SLE patients were screened using the T-SPOT.TB assay, of whom 334 patients tested positive, yielding a positivity rate of 15% (95% confidence interval [CI], 13.5% to 16.5%). The positivity rate was higher in male than female patients and had an increasing trend with age. Multivariable logistic regression analysis showed that patients over 40 (odds ratio [OR], 1.65; 95% CI, 1.29 to 2.10) and with evidence of previous tuberculosis (OR, 4.43; 95% CI, 2.81 to 6.99) were more likely to have positive T-SPOT.TB results, while patients with a SLEDAI-2K score of ≥10 (OR, 0.61; 95% CI, 0.43 to 0.88), a glucocorticoid dose of ≥60 mg/d (OR, 0.62; 95% CI, 0.39 to 0.98), leflunomide (LEF) treatment (OR, 0.51; 95% CI, 0.29 to 0.88), or tacrolimus (FK506) treatment (OR, 0.40; 95% CI, 0.16 to 1.00) were more likely to have negative T-SPOT.TB results. The frequencies of CFP-10-specific gamma interferon (IFN-γ)-secreting T cells were significantly lower in SLE patients with severe disease activity or high-dose glucocorticoids (P < 0.05). The positivity rate of the T-SPOT.TB assay was 15% among SLE patients. Severe, active SLE disease and the use of high-dose glucocorticoids and some types of immunosuppressants are likely to result in negative T-SPOT.TB results. For SLE patients with the above conditions, diagnosing LTBI based on a positive T-SPOT.TB result may lead to underestimation of the prevalence. IMPORTANCE The burden of tuberculosis and systemic lupus erythematosus in China ranks among the top three in the world. Therefore, active screening for LTBI and preventive intervention in SLE patients are of great significance in China. In view of the lack of relevant data in a large sample, we conducted a multicenter, cross-sectional study using T-SPOT.TB as a screening method for LTBI, to investigate the prevalence of LTBI and analyze the factors affecting the results of the T-SPOT.TB assay in SLE patients. Our study showed that the overall positivity rate of the T-SPOT.TB assay in SLE patients was 15.0%, which was lower than the estimated LTBI prevalence in the general population in China (~20%). For SLE patients with severe, active disease, high-dose glucocorticoids, and some types of immunosuppressants, a diagnosis of LTBI based on only positive T-SPOT.TB results may lead to underestimation of the prevalence.

The value of peripheral blood and pleural effusion T-SPOT.TB combined with pleural effusion adenosine deaminase in diagnosis of tuberculous pleurisy / 中国热带医学

@#Abstract: Objective To explore the relationship between peripheral blood and pleural effusion tuberculosis (TB) infection effector T cells, and to further evaluate the value of combined pleural effusion adenosine deaminase (ADA) for rapid diagnosis of tuberculous pleurisy. Methods The test data of 80 cases of tuberculous pleurisy and 70 cases of nontuberculous pleurisy treated in the Sixth People's Hospital of Nantong City from January 2017 to December 2020 were analyzed. The TBinfected effector T cells were also detected simultaneously in the peripheral blood and the pleural effusion by the T-SPOT technique, and the pleural effusion ADA was detected by the rate method. The subject operating characteristic curve (ROC) was applied to take the optimal pleural effusion ADA threshold to compare the sensitivity and specificity of different critical values. Person phase analysis was applied to analyze the correlation between peripheral blood and pleural effusion T-SPOT.TB. Data of peripheral blood, pleural effusion T-SPOT.TB and ADA were integrated. Results When pleural effusion ADA>45 U/L, the sensitivity and specificity for the diagnosis of tuberculous pleurisy were 50.0% and 94.3%, respectively; when ADA > 25.15 U/ L, the sensitivity and specificity were 80.0% and 72.9%. When ADA > 45 U / L, pleural/ blood T-SPOT.TB spot ratio (spot forming cells, SFCs) > 2 times, the specificity for the diagnosis of tuberculous pleurisy was 100% (highest); when 25.15 U/L< pleural effusion ADA ≤ 45 U/L, pleural/blood T-SPOT.TB spot ratio > 2 times, the specificity for the diagnosis of tuberculous pleurisy was 92.3% (second). When pleural effusion ADA ≤ 25.15 U/L, and the pleural effusion/blood T-SPOT.TB spot number ratio > 2 times, with 83.3% specificity (the lowest of the three groups). Conclusions The level of pleural effusion ADA is one of the most used methods for diagnosing tuberculous pleurisy. Further combination of pleural effusion and blood T-SPOT.TB, if the ratio of pleural effusion / blood T-SPOT. TB spots is greater than 2 times, it can further improve the diagnosis rate of tuberculous pleurisy.

Diagnostic Efficacy of T-SPOT.TB for Active Tuberculosis in Adult: A Retrospective Study.

Purpose: To explore the diagnostic efficacy and optimal diagnosis threshold of T-SPOT.TB for active tuberculosis in adults and to evaluate the influential factors for T-SPOT.TB results. Patients and Methods: A retrospective study of 1193 adult inpatients from April 2015 to March 2018 in Ruijin Hospital was conducted. All included patients underwent T-SPOT.TB assay, and were divided into two groups, active tuberculosis (ATB) and non-active tuberculosis (non-ATB) groups. Their demographic data, underlying diseases, personal history and laboratory findings were collected to calculate the diagnostic efficacy at different diagnosis thresholds and analyze the impact factors. Symptoms and imaging features of ATB patients were recorded and analyzed. Results: A total of 114 ATB patients and 1079 non-ATB patients were included in the study, and ATB patients had a higher level of T-SPOT.TB than the non-ATB group. Sensitivity and specificity of T-SPOT.TB for diagnosing ATB are 78.95% and 68.58% as the threshold at 6sfu. In the diagnosis accordance curves, ESAT-6, CFP-10, and max (ESAT-6 or CFP-10) reached the plateau at 40sfu, while sum (ESAT-6 and CFP-10) reached the plateau at 70sfu. Multivariate logistic regression analysis showed that obsolescent tuberculosis (p=0.001), smoking history(p=0.005), diabetes(p=0.035) and advanced age (≥65 years old) (p=0.031) were risk factors for false-positive result of T-SPOT.TB. In terms of imaging features, logistic regression analysis suggested that the thin-wall cavitary lesion was the only feature associated with the result of T-SPOT.TB. Conclusion: As for using T-SPOT.TB test to diagnose active tuberculosis, increased threshold could significantly elevate the diagnosis accordance. And we suggest that the threshold of T-SPOT.TB could be increased to 40sfu for diagnosing ATB. Attention should be paid when diagnose ATB in population with obsolescent tuberculosis, smoking history, diabetes and advanced age, for the risk of false-positive.

Performance of LTBI Screening in Patients with Rheumatic Diseases Using Two Different Interferon-Gamma Releasing Assays.

BACKGROUND: To evaluate the concordance between QuantiFERON-TB Gold in-tube test (QFT-GIT) and T-SPOT.TB test (T-SPOT) for the screening of latent tuberculosis infection (LTBI) in patients with rheumatic diseases (RDs). METHODS: Patients diagnosed as rheumatic diseases (RDs) with clinical indications for test of interferon gamma release test (IGRA) were prospectively recruited from 2019 to 2020. The consistency of QFT-GIT and T-SPOT was assessed by Kappa analysis and the factors associated with the indeterminate results were explored by multivariable logistic analysis. RESULTS: A total of 108 patients with RDs were enrolled, including 64 patients with systemic lupus erythematosus (SLE) and 44 with inflammatory arthritis (26 with rheumatoid arthritis (RA) and 18 with ankylosing spondylitis (AS)). Poor concordance was confirmed between QFT-GIT and T-SPOT results in patients with SLE (K = 0.175, 95% confidence interval [95% CI] [-0.06, 0.40], p < 0.001), whereas concordance was moderate in patients with inflammatory arthritis (K = 0.539, 95% CI [0.11, 0.88], p < 0.001). Among SLE patients, the ratio of indeterminate results in detecting LTBI was significantly higher by QFT-GIT than by T-SPOT (18.8% vs. 4.7%, p = 0.013), while the statistical difference was not achieved in patients with inflammatory arthritis. The multivariable logistic analysis identified that the presence of lower lymphocyte counts (odds ratio [OR] = 0.81, 95% CI [0.68, 0.97], p = 0.020) was the independent predictor of an indeterminate result of the QFT-GIT in SLE patients. CONCLUSIONS: In patients with RDs, the result of screening of LTBI was more definitive by T-SPOT test than QFT, and the concordance was poor especially in the setting of SLE.

Analysis of the diagnostic efficacy of the QuantiFERON-TB Gold In-Tube assay for preoperative differential diagnosis of spinal tuberculosis.

Background: Differential diagnosis of spinal tuberculosis is important for the clinical management of patients, especially in populations with spinal bone destruction. There are few effective tools for preoperative differential diagnosis in these populations. The QuantiFERON-TB Gold In-Tube (QFT-GIT) test has good sensitivity and specificity for the diagnosis of tuberculosis, but its efficacy in preoperative diagnosis of spinal tuberculosis has rarely been investigated. Method: A total of 123 consecutive patients with suspected spinal tuberculosis hospitalized from March 20, 2020, to April 10, 2022, were included, and the QFT-GIT test was performed on each patient. We retrospectively collected clinical data from these patients. A receiver operating characteristic (ROC) curve was plotted with the TB Ag-Nil values. The cutoff point was calculated from the ROC curve of 61 patients in the study cohort, and the diagnostic validity of the cutoff point was verified in a new cohort of 62 patients. The correlations between TB Ag-Nil values and other clinical characteristics of the patients were analyzed. Results: Of the 123 patients included in the study, 51 had confirmed tuberculosis, and 72 had non-tuberculosis disease (AUC=0.866, 95% CI: 0.798-0.933, P<0.0001). In patients with spinal tuberculosis, the QFT-GIT test sensitivity was 92.16% (95% CI: 80.25%-97.46%), and the specificity was 67.14% (95% CI: 54.77%-77.62%). The accuracy of diagnostic tests in the validation cohort increased from 77.42% to 80.65% when a new cutoff point was selected (1.58 IU/mL) from the ROC curve of the study cohort. The TB Ag-Nil values in tuberculosis patients were correlated with the duration of the patients' disease (r=0.4148, P=0.0025). Conclusion: The QFT-GIT test is an important test for preoperative differential diagnosis of spinal tuberculosis with high sensitivity but low specificity. The diagnostic efficacy of the QFT-GIT test can be significantly improved via application of a new threshold (1.58 IU/mL), and the intensity of the QFT-GIT test findings in spinal tuberculosis may be related to the duration of a patient's disease.

Platelets correlate with false negative T-SPOT.TB results by inhibiting interferon-γ production in T cells via degranulation.

Background: T-SPOT.TB (T-SPOT) is widely used for the detection of Mycobacterium tuberculosis infection by detecting interferon-gamma (IFN-γ) release in T lymphocytes. This assay is performed on peripheral blood mononuclear cells (PBMCs) separated by Ficoll density gradient centrifugation, which often contain some residual platelets. Here, we investigated the impact of platelets on T-SPOT assay and related mechanisms. Methods: The correlation between platelet count, platelet-to-lymphocyte ratio (PLR), and the IFN-γ secreting T cells (ISCs) in positive control wells of T-SPOT assay were retrospectively analyzed. T-SPOT assay was performed with un-treated PBMCs, platelets-removed PBMCs, and platelets-enriched PBMCs to confirm the impact of platelets on T-SPOT assay. The activation of platelets and their impact on IFN-γ production in T cells were detected by flow cytometry (FCM). Platelets and T cells were cultured in a mixed culture system and co-culture system respectively, followed by detection of the frequencies of IFN-γ-producing T cells and the levels of intracellular IFN-γ in T cells by FCM. Moreover, the effect of platelet releasate on the T-SPOT assay was evaluated. Results: The ISCs in positive control wells of the T-SPOT assay showed a significant decrease with the increase in platelet count. The PLR of the peripheral blood were negatively correlated with the ISCs in positive control wells of the T-SPOT assay. Removal or enrichment of platelets significantly increased or decreased the ISCs and the positive rate of T-SPOT. Inhibition of platelet activation significantly increased the ISCs of T-SPOT. The frequencies of IFN-γ-producing T cells in PBMCs and the levels of intracellular IFN-γ were significantly reduced by the addition of platelets, both in the mixed culture system and the co-culture system. Platelet releasate upon thrombin activation significantly decreased the ISCs of T-SPOT. Conclusions: Platelets correlate with negative T-SPOT results by inhibiting IFN-γ production in T cells via degranulation.

Novel Automation of an Enzyme-Linked Immunosorbent Spot Assay Testing Method: Comparable Diagnostic Performance of the T-SPOT.TB Test Using Manual Density Gradient Cell Isolation versus Automated Positive Selection with the T-Cell Select Kit.

The diagnosis of latent tuberculosis (TB) infection (LTBI) is critical to improve TB treatment and control, and the T-SPOT.TB test is a commercial enzyme-linked immunosorbent spot assay used for this purpose. The objective of the study was to increase automation and extend the time between blood collection and processing for the T-SPOT.TB test from 0 to 8 h to 0 to 54 h. The previous maximum time between blood collection and processing for the T-SPOT.TB test is 32 h using T-Cell Xtend. For this, we compared the T-SPOT.TB test using manual peripheral blood mononuclear cell (PBMC) isolation by density gradient separation at 0 to 8 h (reference method, control arm) to an automated PBMC isolation method using magnetic beads (T-Cell Select kit) at 0 to 55 h postcollection. A total of 620 subjects were enrolled from 4 study sites, and blood samples were collected from each volunteer, comprising 1,850 paired samples in total. Overall agreement between both methods was 96.8% (confidence interval [CI], 95.9 to 97.6%), with 95.8% (CI, 93.5 to 97.5%) positive and 97.1% negative agreement (CI, 96.1 to 97.9%). In summary, there was a strong overall agreement between the automated and manual T-SPOT.TB test processing methods. The results suggest that the T-SPOT.TB test can be processed using automated positive selection with magnetic beads using T-Cell Select to decrease hands-on time. Also, this cell isolation method allowed for the time between blood collection and processing to range from 0 to 55 h. Additional studies in larger and diverse patient populations including immunocompromised and pediatric patients are needed.

Using TBAg/PHA Ratio for Monitoring TB Treatment: A Prospective Multicenter Study.

The way to monitor tuberculosis (TB) treatment is extremely lacking in clinical practice. The aim of the study is to assess the role of the TBAg/PHA ratio in the treatment monitoring of TB. TB patients were followed up for 6 months and serial T-SPOT.TB (T-SPOT) assays were performed. In patients with successful treatment outcomes, the ESAT-6 sfc, CFP-10 sfc, and TBAg/PHA ratio all showed a decreased trend after the initiation of treatment. Conversely, PHA sfc showed an increased trend after 2 months of treatment. However, these indicators had moderate performance in distinguishing between before and after 6 months of treatment, and the AUC ranged from 0.702 to 0.839. Notably, the TBAg/PHA ratio in patients without risk factors was of important value in differentiation between before and after treatment. The optimal AUC of TBAg/PHA ratio reached up to 0.890. Patients with unsuccessful treatment outcomes showed persistently high levels of TBAg/PHA ratio. The TBAg/PHA ratio in patients after 6 months of treatment showed a certain potential in distinguishing between patients with successful and unsuccessful treatment outcomes. A further calculation of the TBAg/PHA ratio in T-SPOT assay has potential value in the treatment monitoring of TB, but further confirmation is needed.

The diagnostic value of T cell spot test and adenosine deaminase in pleural effusion for tuberculous pleurisy: A systematic review and meta-analysis.

BACKGROUND: Tuberculous infection of T cell spot test (T-SPOT.TB) and adenosine deaminase (ADA) have a high diagnostic value in pleural effusion for tuberculous pleurisy. However, there were major differences in existing research in regard to the clinical application of the two trials. Therefore, we conducted a meta-analysis to systematically evaluate the diagnostic value of T-SPOT.TB and ADA. METHODS: Pubmed, Web of Science and Embase databases were searched to compare diagnosis of tuberculous pleurisy by T-SPOT.TB and ADA. The search period was from inception to August 31, 2021. Statistical analyses were performed using Meta-disc 1.4, Revman 5.4 and Stata 16.0. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were determined. Summary receiver operating characteristic (SROC) curves and the area under the curve (AUC) were used to summarize overall diagnostic performance. RESULTS: 10 qualified original research studies were included, with a total of 2075 patients, of which were 1391 tuberculous pleurisy and 684 non-tuberculous pleurisy. The pooled estimates of diagnostic accuracy of T-SPOT.TB were as follows: sensitivity, 0.88 (95% CI: 0.86-0.90; I2 = 92.7%); specificity, 0.79 (95% CI: 0.76-0.82; I2 = 93.7%); PLR, 4.49 (95% CI: 2.29-8.80; I2 = 94.9%); NLR, 0.15 (95% CI: 0.08-0.30; I2 = 94.3%), DOR, 35.72 (95% CI: 11.15-114.47; I2 = 91.5%). The AUC for SROC was 0.9283 (95% CI: 0.8912-0.9654). The pooled estimates of diagnostic accuracy of ADA were as follows: sensitivity, 0.65 (95% CI: 0.62-0.67; I2 = 98.2%); specificity, 0.90 (95% CI: 0.88-0.92; I2 = 69.4%); PLR, 6.12 (95% CI: 4.71-7.96; I2 = 11.9%); NLR, 0.33 (95% CI: 0.12-0.89; I2 = 99.5%), DOR, 23.18 (95% CI: 12.75-42.14; I2 = 66.7%). The AUC for SROC was 0.9208 (95% CI: 0.9029-0.9387). CONCLUSION: Both T-SPOT.TB and ADA had high value in the diagnosis of tuberculous pleurisy. The sensitivity of T-SPOT.TB was higher than ADA, but the specificity of ADA was higher than T-SPOT.TB. On the whole, T-SPOT. TB had similar diagnostic accuracy to ADA.

Giant Lupus Vulgaris with Negative T-SPOT.TB, a Case Report and Literature Review.

Lupus vulgaris is a paucibacillary form of cutaneous tuberculosis (CTB) which is accounting for 1-2% of all tuberculosis cases. Here, we report a rare huge lupus vulgaris misdiagnosed as sarcoidosis for 11 years. A 65-year-old man presented to dermatology outpatient with a large asymptomatic erythematous plaque and erosions on his neck. Sarcoidosis was initially diagnosed on the basis of negative interferon-gamma release tests and biopsies of lymph nodes and lesions. The patient was treated with long-term oral steroid and immunosuppressive agents, but the lesions expanded gradually. Lupus vulgaris was finally diagnosed by combining molecular detection and mycobacterial culture. The skin lesions were resolved after six months of standard antituberculosis therapy. We report this case to analyze the reasons for the misdiagnosis and review-related literature to further provide experience for the diagnosis and treatment of cutaneous tuberculosis with negative T-SPOT.TB.

Comparison of diagnostic accuracy of QuantiFERON-TB Gold Plus and T-SPOT.TB in the diagnosis of active tuberculosis in febrile patients.

OBJECTIVE: This study aimed to compare the accuracy of QuantiFERON-TB Gold Plus (QFT-Plus) and T-SPOT.TB for diagnosing active tuberculosis (ATB) in febrile patients, to explore influencing factors of positive results and to verify the potential value of QFT-Plus in the identification of ATB and latent tuberculosis infection (LTBI). METHODS: A total of 240 febrile patients with ATB (n = 80) and non-ATB (n = 160) were recruited to assess the accuracy of QFT-Plus and T-SPOT.TB for diagnosing ATB. Multivariable logistic regression was used to analyze the influencing factors of positive results. RESULTS: The proportion of indeterminate results (ITRS) in QFT-Plus and T-SPOT.TB were 3.3% and 0%, respectively. The consistency between the results of the QFT-Plus and T-SPOT.TB was substantial. The area under the receiver operating characteristic curve (AUROC) of the QFT-Plus and T-SPOT.TB for diagnosing ATB was 0.792 and 0.849 (p = 0.070), respectively. The sensitivity of differentiating ATB from non-ATB was 92.2% in QFT-Plus versus 95.0% in T-SPOT.TB. The influencing factors of T-SPOT.TB positive result were male (odds ratio (OR) = 2.33, 95% confidence interval (CI) 1.27-4.26, p = 0.006), evidence of previous TB (OR 11.36, 95% CI 4.62-27.94, p < 0.001), while male (OR = 3.17, 95% CI 1.73-5.84, p < 0.001), evidence of previous TB (OR = 7.58, 95% CI 3.60-15.98, p <0.001), and use of immunosuppressant (OR = 0.49, 95% CI 0.260.94, p = 0.030) were influencing factors for QFT-Plus positive result. There was no significant difference in QFT-Plus in differentiating ATB from LTBI in febrile patients. CONCLUSION: There was no significant difference between QFT-Plus and T-SPOT.TB for diagnosing ATB in febrile patients. QFT-Plus is prone to ITRS. The influencing factors including males, evidence of the previous TB, and use of immunosuppressant should be considered when interpreting positive results.

Diagnostic Performance of a Novel CXCL10 mRNA Release Assay for Mycobacterium tuberculosis Infection.

One-fourth of the world's population has been infected with Mycobacterium tuberculosis (M.tb). Although interferon-gamma release assays (IGRAs) have been shown to be valid methods for identifying M.tb infection and auxiliary methods for diagnosis of active tuberculosis (TB), lower sensitivity and higher indeterminate rate were often detected among immunosuppressed patients. IP-10 was an alternative biomarker due to the higher expression level after M.tb antigen stimulation, but whether CXCL10 mRNA (the gene that transcribes for the IP-10 protein) can be used as a target for M.tb infection diagnosis was limited. Therefore, we aimed to evaluate the performance of a novel M.tb-specific CXCL10 mRNA release assay in diagnosis of M.tb infection. Suspected TB patients and healthy controls were prospectively recruited between March 2018 and November 2019 from three hospitals in China. CXCL10 mRNA release assay and traditional interferon-gamma release assay (T-SPOT.TB) were simultaneously performed on peripheral blood. Of the 1,479 participants enrolled in the study, 352 patients with definite TB and 153 healthy controls were analyzed. CXCL10 mRNA release assay provided a sensitivity of 93.9% (95% CI = 90.8-96.2%) and a specificity of 98.0% (95% CI = 94.3-99.6%) in the diagnosis of M.tb infection, respectively, while T-SPOT.TB gave a sensitivity of 94.5% (95% CI = 91.5-96.6%) and a specificity of 100% (95% CI = 97.6-100.0%) in the diagnosis of M.tb infection, respectively. The diagnostic performance of CXCL10 mRNA release assay was consistent with T-SPOT.TB, with a total coincidence rate of 95.0% (95% CI = 93.0-96.9%) and a Cohen's kappa value of 0.89 (0.84-0.93, p < 0.001). However, among TB patients with HIV co-infection (n = 14), CXCL10 mRNA release assay presented significantly higher positive rate [92.9% (66.1-99.8%) vs. 61.5% (31.6-86.1%), p = 0.029] than those of T-SPOT.TB. These results suggested that M.tb-specific CXCL10 mRNA was a novel and useful target in the diagnosis of M.tb infection.

Diagnóstico de la infección tuberculosa en pacientes inmunodeprimidos y/o candidatos a terapias biológicas mediante el uso combinado de dos pruebas IGRA: T-SPOT.TB/QuantiFERON TB Gold In-Tube vs. T-SPOT.TB/QuantiFERON TB Gold Plus / Diagnosis of Tuberculous Infection in Immunosuppressed Patients and/or Candidates for Biologics Using a Combination of 2 IGRA Tests: T-SPOT.TB/QuantiFERON TB Gold In-Tube vs. T-SPOT.TB/QuantiFERON TB Gold Plus

Introducción: El diagnóstico de la infección tuberculosa latente (ITL) mediante IGRA sigue generando debate. La experiencia empleando dos pruebas IGRA de manera simultánea es escasa. El objetivo de este estudio es comparar los resultados de dos versiones de QuantiFERON-TB Gold (In-Tube/Plus) con los de T-SPOT.TB y analizar la eficacia de esta estrategia dual (T-SPOT.TB + QTF) para el diagnóstico de la ITL en población con alguna condición inmunosupresora.Métodos: Estudio prospectivo (mayo 2015-junio 2017) que incluye 2.999 pacientes inmunodeprimidos y/o candidatos a terapias biológicas, a los que se les realizó de manera simultánea dos IGRA: grupo-1 (1.535 pacientes): T-SPOT.TB + QuantiFERON-TB Gold-In-Tube (QTF-GIT); grupo-2 (1.464 pacientes): T-SPOT.TB + QuantiFERON-TB Gold Plus (QTF-Plus).Resultados: La concordancia entre QTF-GIT y T-SPOT.TB fue del 83,19% (κ = 0,532). Las proporciones de resultados positivos, negativos e indeterminados fueron, respectivamente: 14,33 vs. 17,06%; 82,41 vs. 74,46%; y 3,25 vs. 8,46%. La concordancia entre QTF-Plus y T-SPOT.TB fue del 87,56% (κ=0,609). Las proporciones de resultados positivos, negativos e indeterminados fueron, respectivamente: 15,02 vs. 15,36%; 82,92 vs. 79,37%; y 2,04 vs. 5,25%. Las discordancias entre T-SPOT.TB y QTF-Plus fueron del 12,43%, que implicaban que había 103 pacientes positivos y otros 79 pacientes negativos a expensas exclusivamente de uno de los dos IGRA.Conclusiones: Se evidenció una mayor concordancia entre QTF-Plus y T-SPOT.TB que entre QTF-GIT y T-SPOT.TB. Sin embargo, creemos que la proporción de resultados discordantes entre T-SPOT.TB y QTF-Plus es lo suficientemente relevante clínicamente como para justificar el empleo simultáneo de dos IGRA en este grupo específico de pacientes. (AU)

Introduction: The diagnosis of latent tuberculous infection (LTI) by IGRA continues to generate debate. Experience in the simultaneous use of 2 IGRA tests is scant. The aim of this study was to compare the results of 2 versions of QuantiFERON-TB Gold (In-Tube/Plus) with those of T-SPOT.TB, and to analyse the effectiveness of a dual strategy (T-SPOT.TB + QTF) for the diagnosis of LTI in an immunosuppressed population.Methods: We conducted a prospective study (May 2015-June 2017) that included 2,999 immunosuppressed patients and/or candidates for biologics, in whom 2 simultaneous IGRA tests were performed: Group 1 (1535 patients): T-SPOT.TB + QuantiFERON-TB Gold-In-Tube (QTF-GIT); Group 2 (1464 patients): T-SPOT.TB + QuantiFERON-TB Gold Plus (QTF-Plus).Results: The concordance between QTF-GIT and T-SPOT.TB was 83.19% (κ=0.532). The percentage of positive, negative, and indeterminate results were, respectively: 14.33% vs. 17.06%; 82.41% vs. 74.46%; and 3.25% vs. 8.46%. The concordance between QTF-Plus and T-SPOT.TB was 87.56% (κ=0.609). The percentage of positive, negative, and indeterminate results were, respectively: 15.02% vs. 15.36%; 82.92% vs. 79.37%; and 2.04% vs. 5.25%. Discrepancies between T-SPOT.TB and QTF-Plus were 12.43%, suggesting that 103 patients were positive and another 79 were negative due exclusively to 1 of the 2 IGRAs.Conclusions: Greater concordance was found between QTF-Plus and T-SPOT.TB than between QTF-GIT and T-SPOT.TB. However, we believe that the proportion of discrepancies between T-SPOT.TB and QTF-Plus is sufficiently important from a clinical point of view to justify the simultaneous use of 2 IGRA in this specific patient group. (AU)

[Translated article] Diagnosis of tuberculous infection in immunosuppressed patients and/or candidates for biologics using a combination of 2 IGRA tests: T-SPOT.TB/QuantiFERON TB Gold In-Tube vs. T-SPOT.TB/QuantiFERON TB Gold Plus / Diagnóstico de la infección tuberculosa en pacientes inmunodeprimidos y/o candidatos a terapias biológicas mediante el uso combinado de dos pruebas IGRA: T-SPOT.TB/QuantiFERON TB Gold In-Tube vs. T-SPOT.TB/QuantiFERON TB Gold Plus

Introduction: The diagnosis of latent tuberculous infection (LTI) by IGRA continues to generate debate. Experience in the simultaneous use of 2 IGRA tests is scant. The aim of this study was to compare the results of 2 versions of QuantiFERON-TB Gold (In-Tube/Plus) with those of T-SPOT.TB, and to analyse the effectiveness of a dual strategy (T-SPOT.TB + QTF) for the diagnosis of LTI in an immunosuppressed population.Methods: We conducted a prospective study (May 2015-June 2017) that included 2,999 immunosuppressed patients and/or candidates for biologics, in whom 2 simultaneous IGRA tests were performed: Group 1 (1535 patients): T-SPOT.TB + QuantiFERON-TB Gold-In-Tube (QTF-GIT); Group 2 (1464 patients): T-SPOT.TB + QuantiFERON-TB Gold Plus (QTF-Plus).Results: The concordance between QTF-GIT and T-SPOT.TB was 83.19% (κ=0.532). The percentage of positive, negative, and indeterminate results were, respectively: 14.33% vs. 17.06%; 82.41% vs. 74.46%; and 3.25% vs. 8.46%. The concordance between QTF-Plus and T-SPOT.TB was 87.56% (κ=0.609). The percentage of positive, negative, and indeterminate results were, respectively: 15.02% vs. 15.36%; 82.92% vs. 79.37%; and 2.04% vs. 5.25%. Discrepancies between T-SPOT.TB and QTF-Plus were 12.43%, suggesting that 103 patients were positive and another 79 were negative due exclusively to 1 of the 2 IGRAs.Conclusions: Greater concordance was found between QTF-Plus and T-SPOT.TB than between QTF-GIT and T-SPOT.TB. However, we believe that the proportion of discrepancies between T-SPOT.TB and QTF-Plus is sufficiently important from a clinical point of view to justify the simultaneous use of 2 IGRA in this specific patient group. (AU)

Introducción: El diagnóstico de la infección tuberculosa latente (ITL) mediante IGRA sigue generando debate. La experiencia empleando dos pruebas IGRA de manera simultánea es escasa. El objetivo de este estudio es comparar los resultados de dos versiones de QuantiFERON-TB Gold (In-Tube/Plus) con los de T-SPOT.TB y analizar la eficacia de esta estrategia dual (T-SPOT.TB + QTF) para el diagnóstico de la ITL en población con alguna condición inmunosupresora.Métodos: Estudio prospectivo (mayo 2015-junio 2017) que incluye 2.999 pacientes inmunodeprimidos y/o candidatos a terapias biológicas, a los que se les realizó de manera simultánea dos IGRA: grupo-1 (1.535 pacientes): T-SPOT.TB + QuantiFERON-TB Gold-In-Tube (QTF-GIT); grupo-2 (1.464 pacientes): T-SPOT.TB + QuantiFERON-TB Gold Plus (QTF-Plus).Resultados: La concordancia entre QTF-GIT y T-SPOT.TB fue del 83,19% (κ = 0,532). Las proporciones de resultados positivos, negativos e indeterminados fueron, respectivamente: 14,33 vs. 17,06%; 82,41 vs. 74,46%; y 3,25 vs. 8,46%. La concordancia entre QTF-Plus y T-SPOT.TB fue del 87,56% (κ=0,609). Las proporciones de resultados positivos, negativos e indeterminados fueron, respectivamente: 15,02 vs. 15,36%; 82,92 vs. 79,37%; y 2,04 vs. 5,25%. Las discordancias entre T-SPOT.TB y QTF-Plus fueron del 12,43%, que implicaban que había 103 pacientes positivos y otros 79 pacientes negativos a expensas exclusivamente de uno de los dos IGRA.Conclusiones: Se evidenció una mayor concordancia entre QTF-Plus y T-SPOT.TB que entre QTF-GIT y T-SPOT.TB. Sin embargo, creemos que la proporción de resultados discordantes entre T-SPOT.TB y QTF-Plus es lo suficientemente relevante clínicamente como para justificar el empleo simultáneo de dos IGRA en este grupo específico de pacientes. (AU)