QuantiFERON-TB gold cut-off value: implications for the management of tuberculosis-related ocular inflammation

The immune response in tubercular uveitis and its implications for treatment: From anti-tubercular treatment to host-directed therapies

Tubercular uveitis (TB-uveitis) remains a conundrum in the uveitis field, which is mainly related to the diverse clinical phenotypes of TB-uveitis. Moreover, it remains difficult to differentiate whether Mycobacterium tuberculosis (Mtb) is present in the ocular tissues, elicits a heightened immune response without Mtb invasion in ocular tissues, or even induces an anti-retinal autoimmune response. Gaps in the immuno-pathological knowledge of TB-uveitis likely delay timely diagnosis and appropriate management. In the last decade, the immunopathophysiology of TB-uveitis and its clinical management, including experts' consensus to treat or not to treat certain conditions with anti-tubercular treatment (ATT), have been extensively investigated. In the meantime, research on TB treatment, in general, is shifting more toward host-directed therapies (HDT). Given the complexities of the host-Mtb interaction, enhancement of the host immune response is expected to boost the effectiveness of ATT and help overcome the rising burden of drug-resistant Mtb strains in the population. This review will summarize the current knowledge on the immunopathophysiology of TB-uveitis and recent advances in treatment modalities and outcomes of TB-uveitis, capturing results gathered from high- and low-burden TB countries with ATT as the mainstay of treatment. Moreover, we outline the recent progress of HDT development in the pulmonary TB field and discuss the possibility of its applicability to TB-uveitis. The concept of HDT might help direct future development of efficacious therapy for TB-uveitis, although more in-depth research on the immunoregulation of this disease is still necessary.

Usefulness of the QuantiFERON test for the diagnosis of tubercular uveitis and the predictions of response to antituberculosis treatment

AIMS

Few studies have evaluated the contribution of QuantiFERON test for the diagnosis of tubercular uveitis in non-endemic countries for tuberculosis (TB). The objective of the present study was to evaluate the value of the QuantiFERON test in a large cohort of patients with uveitis for both the diagnosis of tubercular uveitis and antituberculosis treatment (ATT) response prediction.

METHODS

A single-centre retrospective study including consecutive adult patients with uveitis who were prescribed a QuantiFERON test between January 2003 and December 2019 was performed. Adjusted ORs (aORs) were calculated between patients with uveitis responding and not responding to ATT according to the Collaborative Ocular Tuberculosis Study (COTS) group diagnostic criteria. Sensitivity (SE), specificity (Sp), and positive and negative predictive values of the QuantiFERON test were calculated.

RESULTS

A total of 1075 patients were included in the study; 178 (16.5%) were found positive using the QuantiFERON test. Among the 178 positive patients, 62 (35%) had a diagnosis of tubercular uveitis according to the updated COTS classification; all received ATT for 6 months; and 44/62 (71%) responded to ATT. A QuantiFERON test value of >2 IU/mL was associated with a greater chance of responding to ATT (aOR=36.7, 95% CI 7.2 to 185.9, p<0.001). The optimal threshold to maximise both Sp and SE for diagnosis of TB uveitis was 4 IU/mL.

CONCLUSION

One-sixth of the patients diagnosed with uveitis had a positive QuantiFERON test. The QuantiFERON threshold with the optimal SE and Sp for the diagnosis of tubercular uveitis was 4 IU/mL.

TRIAL REGISTRATION NUMBER

NCT03863782.

Anti-tubercular therapy in the treatment of tubercular uveitis: A systematic review and meta-analysis

We quantitatively evaluated the efficacy of antitubercular therapy (ATT) in tubercular uveitis (TBU) patients. Main outcome measures include inflammation recurrence, inflammation reduction, complete resolution of inflammation, improved visual acuity (VA), ability to taper corticosteroids to < 10 mg/day without inflammatory progression, and use of adjunctive immunosuppressants while on ATT. This review is prospectively registered in PROSPERO (CRD42020206845). Forty-nine studies reporting data for 4,017 TBU patients were included. In comparative studies, the odds ratio (OR) of inflammatory recurrence was 0.33 (95%CI:0.19-0.60) for TBU patients treated with ATT±corticosteroid versus no ATT. For TBU patients treated with ATT±corticosteroid, the pooled absolute incidences of inflammatory recurrence, inflammatory reduction, complete resolution of inflammation, and visual acuity improvement were 13% (n=310/2,216; 95%CI:9-18), 81% (n=217/276; 95%CI: 62-95), 83% (n=1,167/1,812; 95%CI: 77-89), and 65% (n=347/542; 95%CI:51-78), respectively. Corticosteroids were tapered to <10 mg/day without inflammatory progression in 91% (n=326/395; 95%CI:78-99) of patients, 9% (n=121/1,376; 95%CI:6-13) of whom were administered concomitant immunosuppressive agents alongside ATT. We conclude that treatment of TBU with ATT±corticosteroid is associated with a high level of control or improvement of inflammation. More prospective studies with detailed reporting of ATT regimens, patient subgroups, and outcomes are required to better evaluate ATT effectiveness.

Role of Interferon-Gamma Release Assay for the Diagnosis and Clinical Follow up in Ocular Tuberculosis

PURPOSE

To assess the performance of interferon-gamma release assay (IGRA) associated with tuberculosis skin test (TST) for ocular tuberculosis (OTB) diagnosis and therapeutic decision making.

METHOD

One hundred and ninety-one patients with ocular inflammation were prospectively followed-up. Patients with clinical signs highly suspected of OTB, TST≥10 mm, and/or IGRA≥0.35 IU/mL received antitubercular therapy (ATT). Sensitivity (Se), specificity (Sp), and area under the curve (AUC) were assessed.

RESULTS

Seventy-two (37.7%) patients received ATT for presumed OTB. Combining TST and IGRA had Se=89.6%, Sp=99.2%, and AUC (0.98) significantly higher compared to TST (0.85, Z=6.3, p<.001) or IGRA (0.95, Z=2.5, p=.01). Prior history of corticosteroids or immunosuppressant with concomitantly oral prednisone and baseline IGRA> 2.0 IU/mL was associated significantly with more recurrences in ATT patients (p=.01)      .

CONCLUSION

Considering TST and IGRA together was more effective in assessing OTB diagnosis. The real value of the IGRA test to predict recurrences needs further studies.

The Large Hellenic Study of Uveitis: Diagnostic and Therapeutic Algorithms, Complications, and Final Outcome

PURPOSE

The purpose of this study is to present the diagnostic and therapeutic algorithms, complications, and final outcome in the management of uveitic patients at a tertiary academic referral center.

DESIGN

Observational study.

METHODS

Analysis of the archives of 6191 uveitic patients at the Ocular Inflammation Service of the Department of Ophthalmology of the University Hospital of Ioannina in Greece from 1991 to 2020.

RESULTS

During the 30 years of the study, the diagnostic ability climbed from 45.43% (1991-1995) to 73.4% (2016-2020). This improvement was linked to several factors including the increase in the number of diagnostic paracenteses for the analysis of intraocular fluids, the range and quality of laboratory blood tests, the multimodal ophthalmic imaging, the proper use of nonophthalmic imaging, and the multidisciplinary approach. The degree of uveitis-related complications was related to the severity and cause of inflammation, the recurrence rate, inappropriate treatment, and the prolonged or initially inactive inflammation. The 3 most common complications included cataract, macular edema, and glaucoma. Apart from the modern treatments and surgical techniques, the 3-month preoperative control of inflammation played a critical role in the surgical outcomes. The percentage of patients with a successful outcome increased from 72% (2001-2005) to 90.50% (2016-2020). The center's experience, prompt referral, patient's compliance, and regular follow-ups are associated with a better outcome. The analysis of the results allowed the development of diagnostic and therapeutic algorithms.

CONCLUSIONS

Developing diagnostic and therapeutic algorithms allows for the efficient management of uveitis, leading to better visual outcome and therefore a better quality of life.

Interferon-gamma release assays in tuberculous uveitis: a comprehensive review

Tuberculous uveitis (TBU) comprises a broad clinical spectrum of ocular manifestations, making its diagnosis challenging. Ophthalmologists usually require evidence from investigations to confirm or support a clinical diagnosis of TBU. Since direct isolation of the causative organism from ocular specimens has limitations owing to the small volume of the ocular specimens, resultant test positivities are low in yield. Immunodiagnostic tests, including the tuberculin skin test and interferon-gamma release assays (IGRAs), can help support a clinical diagnosis of TBU. Unlike the tuberculin skin test, IGRAs are in vitro tests that require a single visit and are not affected by prior Bacillus Calmette-Guerin vaccination. Currently, available IGRAs consist of different techniques and interpretation methods. Moreover, newer generations have been developed to improve the sensitivity and ability to detect active tuberculosis. This narrative review collates salient practice points as a reference for general ophthalmologists, such as evidence for the utilization of IGRAs in patients with suspected TBU, and summarizes basic knowledge and details of clinical applications of these tests in a clinical setting.

BTS clinical statement for the diagnosis and management of ocular tuberculosis

The BTS clinical statement for the diagnosis and management of ocular tuberculosis (TB) draws on the expertise of both TB and and ophthalmic specialists to outline the current understanding of disease pathogenesis, diagnosis and management in adults. Published literature lacks high-quality evidence to inform clinical practice and there is also a paucity of data from animal models to elucidate mechanisms of disease. However, in order to improve and standardise patient care, this statement provides consensus points with the currently available data and agreed best practice.

Infectious Posterior Uveitis - Toxoplasmosis, Treponema, Tuberculosis (TTT)

Toxoplasma gondii, Treponema pallidum and Mycobacterium tuberculosis are the most important infectious causes of posterior uveitis. The epidemiology, clinical picture, diagnostic and treatment strategies of these diseases are presented.

Effect of adjusted cut-offs of interferon-γ release assays on diagnosis of tuberculosis in patients with fever of unknown origin

Background

Tuberculosis (TB) is a leading cause of fever of unknown origin (FUO). In recent years, interferon-γ release assays (IGRAs) have been widely utilized and the cut-off values given by the manufacturers are set in countries where rates of TB are not as high.

Methods

A prospective cohort study was conducted in a Chinese general hospital to evaluate the diagnostic performance of T-SPOT.TB (T-SPOT) and QuantiFERON-TB Gold (QFT) in detecting active TB (ATB) in a high TB endemic area. Test results were compared with the culture and clinically confirmed diagnosis. Further, we explored an alternative method of interpreting IGRAs by increasing the cut-off values.

Results

The sensitivity and specificity of T-SPOT in detecting ATB were 85.3% (95% CI 81.6–94.0%) and 71.8% (95% CI 67.3–76.0%), respectively. The sensitivity and specificity of QFT were 72.3% (95% CI 62.8–80.1%) and 77.0% (95% CI 72.7–80.8%), respectively. Receiver operating characteristic analysis was used for evaluation of different cut-off values. When the cut-off values were adjusted as 125 spot-forming cells (SFCs)/ 2.5*10⁵ cells for T-SPOT and 4.0 IU/ml for QFT, the specificity could be improved to > 90.0% (90.3% and 94.1%, respectively), and the sensitivity were 43.1% and 41.6%, respectively. The new adjusted cut-off values were validated in another independent validation cohort.

Conclusion

The adjusted cut-off values of the two assays considerably improved the diagnostic value when applied to FUO patients in clinical settings.

Tubercular Uveitis in Uveitis Cases in a High TB and HIV Setting: A Prospective Cohort Study

Purpose

The diagnosis of tubercular uveitis (TBU) is difficult. The lack of a diagnostic gold standard has contributed to challenges in determining the true prevalence and clinical predictors of TBU. We aimed to determine the proportion of TBU cases in adults with uveitis and to examine clinical features associated with TBU.

Methods

A prospective cohort study of adult uveitis cases after exclusion of other specific etiologies. The diagnosis of TBU was based on a composite reference of: any clinical signs of uveitis; exclusion of other causes of uveitis; and positive QuantiFERON-Gold test, tuberculin skin test, and/or ocular TB polymerase chain reaction.

Results

Of 79 cases analyzed, 49 (62%) had TBU. Female sex (P = 0.001) and chronic uveitis (P = 0.006) cases were more common in the TBU group than the non-TBU group whereas diffuse choroiditis (P = 0.010) and HIV-positive (P = 0.001) cases were less common. Choroidal granulomas (P = 0.176) and serpiginous-like choroiditis (P = 0.292) were more common in TBU group, albeit not significantly. On univariate analysis, female sex (odds ratio, 5.1; P = 0.002), negative HIV status (odds ratio, 0.2; P = 0.001), and chronic uveitis (odds ratio, 4.1; P = 0.008) were associated with TBU. A negative HIV test was associated with TBU on multivariate analysis (P = 0.049).

Conclusions

A high proportion of cases had TBU. Our study did not significantly confirm some of the clinical features associated with TBU reported in other studies.

Translational Relevance

Our study highlights the difficulties in determining the proportion and clinical predictors of TBU, especially in the absence of a gold standard diagnostic test.

The Association between QuantiFERON-TB Gold Test and Clinical Manifestations of Uveitis in the United States

PURPOSE

To report the prevalence of QuantiFERON-TB Gold (QFT-G) positivity among uveitis patients compared to general population and to evaluate the differences in clinical features of uveitis.

DESIGN

Retrospective cohort study.

METHODS

SETTING: Institutional.

PATIENT POPULATION

418 consecutive new uveitis patients, regardless of clinical suspicion, were tested for QFT-G.

OBSERVATION PROCEDURES

Demographics, TB risk factors, clinical characteristics of uveitis were collected.

MAIN OUTCOME MEASURES

The frequency of QFT-G positivity among uveitis patients and characteristic clinical features among QFT-G positive patients.

RESULTS

QFT-G positivity was found in 60/418 patients with uveitis (14.4%, 95% CI: 11.18 - 18.14) higher than the general US population (5%, 95% CI: 4.2 - 5.8, p<.001). Age, gender and residence were similar between QFT-G positive and negative groups. Uveitis patients with positive QFT-G were more likely to be foreign born or have a recent travel history (OR:5.84; 95% CI: 2.83 - 12.05; p<.001). QFT-G positive patients were more likely to present with granulomatous uveitis (OR 2.90; 95%CI 1.36 - 6.21; p=.006). No significant association was found with specific clinical features such as choroiditis, retinal vasculitis, occlusive vasculitis, and serpiginoid choroiditis (p>.05 for each). Prevalence of TB-uveitis based on treatment response was 1.19%.

CONCLUSIONS

Our study demonstrates significantly higher prevalence of QFT-G positivity among uveitis patients compared to average US population. Characteristic signs of TB uveitis reported in endemic countries were not seen in this cohort. Implications of higher prevalence of QFT-G positivity among uveitis patients require further investigation.

Distinct recurrence pattern in a case of bilateral tubercular posterior uveitis: reporting a unique clinical morphology and management challenge

Intraocular tuberculosis has protean clinical manifestations and remains an important etiological differential for uveitis in an endemic region. A 27-year-old male presented with visual acuity of counting fingers close to face in right (OD) and 20/25 in left eye (OS). Examination revealed a choroidal granuloma in OS and healed serpiginous-like choroiditis in OD. Antitubercular therapy was started with systemic corticosteroids. Granuloma resolved completely; however, the patient presented with neuroretinitis and posterior scleritis, as first and second recurrence, respectively, within a oneyear period. These were managed with systemic corticosteroids and immunosuppressive therapy was added, after second recurrence. The patient responded well and maintains remission. This case presented a clinical challenge with distinct recurrence patterns of tubercular posterior uveitis in the same eye, which has not been reported before. Successful management entailed use of antitubercular therapy, corticosteroids, and immunosuppressive therapy in a step-ladder approach, resulting in preservation of vision and achieving long-term remission.

Role of interferon gamma release assay in the diagnosis and management of Mycobacterium tuberculosis-associated uveitis: a review

Tuberculosis (TB)-associated uveitis is a common cause of infectious uveitis in the developing world. Diagnosis of TB uveitis remains a challenge. The role of interferon gamma release assays (IGRAs) is uncertain. Herein we summarise the available literature on the utility of IGRAs in the diagnosis and management of TB uveitis. We searched PubMed database from 1 August 2010 to 31 July 2020 using the following keywords alone and in combination: 'interferon-gamma release assay', 'QuantiFERON', 'T-SPOT.TB', 'TB uveitis', 'serpiginous like choroiditis', 'tuberculoma', 'TB vasculitis', 'TB panuveitis' and 'ocular tuberculosis'. Data from 58 relevant studies were collated. The review is focused on currently marketed versions of IGRA tests: QuantiFERON-TB Gold In-Tube assay, QuantiFERON-TB Gold Plus assay (QFT-Plus) and T-SPOT.TB. We found limited evidence regarding the diagnostic utility of IGRA in patients with uveitis. No study was identified evaluating the newer QFT test-the QFT-Plus-in patients with uveitis. Similarly, there is lack of data directly comparing QFT-Plus with T-SPOT.TB specifically for the diagnosis of TB uveitis.

Prognosis of Ocular Tuberculosis Following Long-Term Antitubercular Therapy

Purpose: This study presents clinical features and prognosis after long-term (12-18 months) antitubercular therapy (ATT) in patients with ocular tuberculosis (OTB) in East China, an endemic area of tuberculosis. Methods: This retrospective study reviewed data from OTB patients treated at the Eye and ENT Hospital of Fudan University from 2008 to 2018. All the patients completed a minimum follow-up of 6 months after the cessation of ATT. Results: Sixty-six patients with OTB were studied. The ocular manifestations included retinal vasculitis (51.6%), choroiditis (24.2%), panuveitis (23.2%), intermediate uveitis (7.4%), scleritis (5.3%), anterior uveitis (2.1%), and optic neuropathy (1%). Except for two patients (ATT for 6 months), all other patients (64/66, 96.97%) received ATT for at least 12 months (6 patients for 12 months, 30 patients for 15 months, and 28 patients for 18 months). Treatment in conjunction with oral corticosteroids was used in 48 patients (72.7%). The average initial best-corrected visual acuity (BCVA) was 0.8 ± 0.64 (LogMAR), which improved to 0.31 ± 0.35 (LogMAR) at the last follow-up (P < 0.05). The final BCVA was significantly associated with the initial BCVA and the duration of clinical symptoms. A complete remission of uveitis was achieved in 97% of the patients. Conclusions: This study observed a favorable prognosis with long-term ATT regimens. Patients with better baseline visual acuity and a shorter duration of clinical symptoms before diagnosis had a better prognosis.

Immune Privilege: The Microbiome and Uveitis

Immune privilege (IP), a term introduced to explain the unpredicted acceptance of allogeneic grafts by the eye and the brain, is considered a unique property of these tissues. However, immune responses are modified by the tissue in which they occur, most of which possess IP to some degree. The eye therefore displays a spectrum of IP because it comprises several tissues. IP as originally conceived can only apply to the retina as it contains few tissue-resident bone-marrow derived myeloid cells and is immunologically shielded by a sophisticated barrier – an inner vascular and an outer epithelial barrier at the retinal pigment epithelium. The vascular barrier comprises the vascular endothelium and the glia limitans. Immune cells do not cross the blood-retinal barrier (BRB) despite two-way transport of interstitial fluid, governed by tissue oncotic pressure. The BRB, and the blood-brain barrier (BBB) mature in the neonatal period under signals from the expanding microbiome and by 18 months are fully established. However, the adult eye is susceptible to intraocular inflammation (uveitis; frequency ~200/100,000 population). Uveitis involving the retinal parenchyma (posterior uveitis, PU) breaches IP, while IP is essentially irrelevant in inflammation involving the ocular chambers, uveal tract and ocular coats (anterior/intermediate uveitis/sclerouveitis, AU). Infections cause ~50% cases of AU and PU but infection may also underlie the pathogenesis of immune-mediated “non-infectious” uveitis. Dysbiosis accompanies the commonest form, HLA-B27–associated AU, while latent infections underlie BRB breakdown in PU. This review considers the pathogenesis of uveitis in the context of IP, infection, environment, and the microbiome.

[Observational study of QuantiFERON® management for ocular tuberculosis diagnosis: Analysis of 244 consecutive tests]

INTRODUCTION

Ocular tuberculosis (TB) diagnosisremains difficult and quantiferon (QFT) contribution needs still yet to be specified, despite its generalization in France. The purpose of this observational study is to assess in which ocular inflammation (OI) presentation QFT is prescribed and to evaluate the added value of new QuantiFERON®-TB Gold Plus (QFT-Plus) test for diagnosis ocular TB diagnosis.

PATIENTS AND METHODS

Monocentric, observational study, carried out in an ophthalmology department over a period of 5 months. Inclusion criteria were defined as an existence of an OI for which a QFT-Plus test was part of the etiological investigations. Of the 316 consecutive files, 72 were excluded (indeterminate test, prescription before anti-TNFα or immunosuppressant initiation, missing data, wrong indication) and 244 were selected and divided into two groups: group one (anterior uveitis/episcleritis, n=129) and group two (intermediate/posterior uveitis/optic neuritis/ocular myositis, n=115). All positive QFT patients underwent an etiological investigation including thoracic imaging.

RESULTS

Forty-five patients, aged 52±12 years, had positive QFT (18.5%), including 18 patients for group 1 and 27 for group 2. Living in TB-endemic area, TB exposure and chest imaging abnormalities were identified in 70%, 27% and 22% of cases, respectively. OI was chronic in 36% of cases (group one, 4/18; group two, 12/27). None of the 18 patients, in group 1, received anti-tuberculosis treatment (ATT) or experienced a relapse during one-year follow-up. Four QFT+ patients, from group 2 (15%) had another associated disease explaining their uveitis. Among the 23 other patients without identified etiology, 13 had at least one relevant ophthalmological signs predictive of TB uveitis (posterior synechiae, retinal vasculitis and/or choroidal granuloma) (59%). Eleven patients received a 6-month ATT trial. Radiological abnormalities and granulomas at angiography were significantly more frequent among treated patients (p=0.03 and 0.001, respectively). A full OI recovery was observed for 8 patients (73%), considered ex-post as ocular TB. Nine patients in group 2 received rifampicin/isoniazid dual therapy for 3 months, but no conclusion could be drawn as to the benefit of such prescription on OI. QFT rate comparison, according to CD4 stimulation by ESAT-6/CFP-10 peptides or by CD4/CD8 co-stimulation, was comparable and found only 4 cases of discrepancy (1.6%). None of these 4 cases had ocular TB diagnosis.

CONCLUSION

Positive QFT frequency among patients consulting for posterior OI remains high. In this study, radiological abnormalities and granulomas at angiography seemed to be more closely related to clinician decision for starting ATT trial in QFT+ patients, which was effective in 73% of cases. QFT-Plus does not seem more relevant than QFT-TB in exploring an OI. Prospective studies are necessary to codify QFT management in the etiological assessment of OI and clearly define ATT trial indications as well as their modalities.

Pathogenesis of ocular tuberculosis: New observations and future directions

Ocular tuberculosis (OTB) encompasses all forms of intra- and extra-ocular inflammation associated with Mycobacterium tuberculosis (Mtb) infection. However, the organism is rarely found in ocular fluid samples of diseased eyes, rendering the pathomechanisms of the disease unclear. This confounds clinical decision-making in diagnosis and treatment of OTB. Here, we critically review existing human and animal data related to ocular inflammation and TB pathogenesis to unravel likely pathomechanisms of OTB. Broadly there appear to be two fundamental mechanisms that may underlie the development of TB-associated ocular inflammation: a. inflammatory response to live/replicating Mtb in the eye, and b. immune mediated ocular inflammation induced by non-viable Mtb or its components in the eye. This distinction is significant as in direct Mtb-driven mechanisms, diagnosis and treatment would be aimed at detection of Mtb-infection and its elimination; while indirect mechanisms would primarily require anti-inflammatory therapy with adjunctive anti-TB therapy. Further, we discuss how that most clinical phenotypes of OTB likely represent a combination of both mechanisms, with one being predominant than the other.

Collaborative Ocular Tuberculosis Study Consensus Guidelines on the Management of Tubercular Uveitis-Report 2: Guidelines for Initiating Antitubercular Therapy in Anterior Uveitis, Intermediate Uveitis, Panuveitis, and Retinal Vasculitis

TOPIC

The Collaborative Ocular Tuberculosis Study (COTS), supported by the International Ocular Inflammation Society, International Uveitis Study Group, and Foster Ocular Immunological Society, set up an international, expert-led consensus project to develop evidence- and experience-based guidelines for the management of tubercular uveitis (TBU).

CLINICAL RELEVANCE

The absence of international agreement on the use of antitubercular therapy (ATT) in patients with TBU contributes to a significant heterogeneity in the approach to the management of this condition.

METHODS

Consensus statements for the initiation of ATT in TBU were generated using a 2-step modified Delphi technique. In Delphi step 1, a smart web-based survey based on background evidence from published literature was prepared to collect the opinion of 81 international experts on the use of ATT in different clinical scenarios. The survey included 324 questions related to tubercular anterior uveitis (TAU), tubercular intermediate uveitis (TIU), tubercular panuveitis (TPU), and tubercular retinal vasculitis (TRV) administered by the experts, after which the COTS group met in November 2019 for a systematic and critical discussion of the statements in accordance with the second round of the modified Delphi process.

RESULTS

Forty-four consensus statements on the initiation of ATT in TAU, TIU, TPU, and TRV were obtained, based on ocular phenotypes suggestive of TBU and corroborative evidence of tuberculosis, provided by several combinations of immunologic and radiologic test results. Experts agreed on initiating ATT in recurrent TAU, TIU, TPU, and active TRV depending on the TB endemicity. In the presence of positive results for any 1 of the immunologic tests along with radiologic features suggestive of past evidence of tuberculosis infection. In patients with a first episode of TAU, consensus to initiate ATT was reached only if both immunologic and radiologic test results were positive.

DISCUSSION

The COTS consensus guidelines were generated based on the evidence from published literature, specialists' opinions, and logic construction to address the initiation of ATT in TBU. The guidelines also should inform public policy by adding specific types of TBU to the list of conditions that should be treated as tuberculosis.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Prevalence of Positive QuantiFERON-TB Gold In-Tube Test in Uveitis and its Clinical Implications in a Country Nonendemic for Tuberculosis

PURPOSE

To report on the prevalence and clinical implications of positive QuantiFERON-Gold (QFT-G) test results in the diagnostic evaluation of a large cohort of consecutive patients with uveitis in the Netherlands.

DESIGN

Retrospective cross-sectional study.

METHODS

This study included 710 consecutive patients who all underwent evaluation for uveitis including QFT-G testing. The ocular features, comorbidity, and abnormalities in diagnostic imaging and laboratory tests were registered for QFT-G-positive patients with uveitis.

RESULTS

Of all patients, 13% (92/710) were positive for QFT-G. Previously treated tuberculosis (TB) was documented in 2 patients. Of all 92 QFT-G-positive patients, culture-proven active TB was observed in 1 case. The proportion of patients with uveitis of unknown etiology was higher in QFT-G-positive than in the QFT-G-negative patients (54/92, 59% vs 238/618, 39%; P = .0004). The uveitis features of QFT-G-positive patients were mainly nonspecific. Of all QFT-G-positive patients with uveitis, 17 patients had chest imaging changes suggesting either TB or sarcoidosis. Twenty-nine QFT-G-positive patients with otherwise unexplained uveitis completed antituberculous therapy (29/710; 4% of all included patients) with beneficial effect in most cases.

CONCLUSION

The QFT-G tested positive in 13% of patients with uveitis in the Netherlands, whereas only sporadic patients had a documented previous or active TB infection. The proportion of patients with unexplained uveitis was higher in QFT-G-positive patients. Though the association between uveitis and a positive QFT-G test might be coincidental, the majority of treated QFT-G-positive patients with otherwise unexplained severe uveitis cause had a beneficial response to antituberculous therapy.

Collaborative Ocular Tuberculosis Study Consensus Guidelines on the Management of Tubercular Uveitis-Report 1: Guidelines for Initiating Antitubercular Therapy in Tubercular Choroiditis

TOPIC

An international, expert-led consensus initiative organized by the Collaborative Ocular Tuberculosis Study (COTS), along with the International Ocular Inflammation Society and the International Uveitis Study Group, systematically developed evidence- and experience-based recommendations for the treatment of tubercular choroiditis.

CLINICAL RELEVANCE

The diagnosis and management of tubercular uveitis (TBU) pose a significant challenge. Current guidelines and literature are insufficient to guide physicians regarding the initiation of antitubercular therapy (ATT) in patients with TBU.

METHODS

An international expert steering subcommittee of the COTS group identified clinical questions and conducted a systematic review of the published literature on the use of ATT for tubercular choroiditis. Using an interactive online questionnaire, guided by background knowledge from published literature, 81 global experts (including ophthalmologists, pulmonologists, and infectious disease physicians) generated preliminary consensus statements for initiating ATT in tubercular choroiditis, using Oxford levels of medical evidence. In total, 162 statements were identified regarding when to initiate ATT in patients with tubercular serpiginous-like choroiditis, tuberculoma, and tubercular focal or multifocal choroiditis. The COTS group members met in November 2018 to refine these statements by a 2-step modified Delphi process.

RESULTS

Seventy consensus statements addressed the initiation of ATT in the 3 subtypes of tubercular choroiditis, and in addition, 10 consensus statements were developed regarding the use of adjunctive therapy in tubercular choroiditis. Experts agreed on initiating ATT in tubercular choroiditis in the presence of positive results for any 1 of the positive immunologic tests along with radiologic features suggestive of tuberculosis. For tubercular serpiginous-like choroiditis and tuberculoma, positive results from even 1 positive immunologic test were considered sufficient to recommend ATT, even if there were no radiologic features suggestive of tuberculosis.

DISCUSSION

Consensus guidelines were developed to guide the initiation of ATT in patients with tubercular choroiditis, based on the published literature, expert opinion, and practical experience, to bridge the gap between clinical need and available medical evidence.

No Evidence for Circulating Retina Specific Autoreactive T-cells in Latent Tuberculosis-associated Uveitis and Sarcoid Uveitis

Purpose: To detect circulating retina-specific autoreactive CD4⁺ T-cells and antiretinal antibodies (ARA) in latent tuberculosis (TB)-associated uveitis or sarcoid uveitis patients.Methods: The presence of crude retinal extract (RE) autoreactive CD4⁺ T-cells was determined by a highly sensitive flowcytometric-based technique examining co-expression of CD25 and CD134 (OX40) on RE stimulated PBMC. The presence of ARA in available matched serum samples was assessed by indirect immunofluorescence.Results: No autoreactive CD4⁺ T-cells against RE could be detected in either latent TB-associated uveitis or sarcoid uveitis patients, while ARA were detected in the serum of the majority (5/6) of latent TB-associated uveitis and all (3/3) sarcoid uveitis patients.Conclusion: Even with the use of this highly sensitive flowcytometric technique circulating retina-specific autoreactive CD4⁺ T-cells could not be detected. In contrast, ARA were detected in the majority of patients indicating an adaptive humoral immune response toward retinal antigens had occurred.

Visual and treatment outcomes of tubercular uveitis: a prospective case series from a referral hospital in Pakistan

Objective

Pakistan is the fifth highest TB burden country. Tuberculous uveitis (TbU) is a form of extrapulmonary TB, that is not uncommon in high burden country but very limited data is available on its outcome. The aim of the study is to assess the outcome of TbU with anti-tuberculous treatment (ATT).

Results

A prospective study was conducted at Jinnah Medical College Hospital (JMCH) Karachi, Pakistan from July to December 2017. Patients with suspected TbU were started on standard ATT chemotherapy for 12 months. Their response was assessed via slit lamp examination and visual acuity at 1, 3, 6 and 12 months of treatment. Forty patients with probable TbU were treated with ATT, mean age was 36 ± 3 years and 24 (60%) were females. Around 26 (65%) had Monteux test of 15 mm or more. History of TB contact was positive in 24 (60%) and 12 (30%) had previous history of TB. All patients complained for blurring of vision and floaters. Posterior uveitis seen in 36 (90%) of patients. Complete response achieved in 32 (80%) after ATT while 6 (14%) had changed in inflammation and 2 (6%) had no benefit.

Current Practices in Ocular Tuberculosis: A Survey of Brazilian Specialists

Purpose: To describe the approach of Brazilian specialists in the diagnosis and treatment of tuberculosis-associated uveitis (TBU).Methods: Members of the Brazilian Uveitis Society received an electronic invitation to participate in an online questionnaire.Results: Of the 169 invited specialists, 78 answered the questionnaire. Specialists evaluated 5.6 patients with TBU annually. Tuberculin skin test (TST, 81%) was primarily used for diagnosis. Patients with presumed TBU should always be tested for syphilis and HIV according to 51 (88%) and 47 (81%) of respondents, respectively. Chest computed tomography (CT, 72%) was preferable to chest radiography (CXR) for diagnosis. A positive TST (81%) and CXR (60%) were the main indicators of anti-tuberculous therapy, with 34%, 39%, and 14% of specialists treating for 6, 9, and 12 months, respectively.Conclusions: TST remains the preferred method for TBU diagnosis and prompt treatment by Brazilian specialists, though there is no consensus regarding disease treatment and management.

Type 1 interferon-inducible gene expression in QuantiFERON Gold TB-positive uveitis: A tool to stratify a high versus low risk of active tuberculosis?

QuantiFERON-Gold TB (QFT)-positive patients with undetermined cause of uveitis are problematic in terms of whether to diagnose and treat them for tuberculosis (TB). Here, we investigated whether peripheral blood expression of type 1 interferon (IFN)-inducible genes may be of use to stratify QFT-positive patients with uveitis into groups of high versus low risk of having active TB-associated uveitis. We recruited all new uveitis patients in Cipto Mangunkusumo Hospital, Jakarta, Indonesia for one year. We included 12 patients with uveitis and clinically diagnosed active pulmonary TB, 58 QFT-positive patients with uveitis of unknown cause, 10 newly diagnosed sputum-positive active pulmonary TB patients without uveitis and 23 QFT-negative healthy controls. Expression of 35 type 1 IFN-inducible genes was measured in peripheral blood cells from active pulmonary TB patients without uveitis and healthy controls. Differentially expressed genes were identified and used for further clustering analyses of the uveitis groups. A type-1 IFN gene signature score was calculated and the optimal cut-off value for this score to differentiate active pulmonary TB from healthy controls was determined and applied to QFT-positive patients with uveitis of unknown cause. Ten type 1 IFN-inducible genes were differentially expressed between active pulmonary TB and healthy controls. Expression of these 10 genes in QFT-positive patients with uveitis of unknown cause revealed three groups: 1); patients resembling active pulmonary TB, 2); patients resembling healthy controls, and 3); patients displaying an in-between gene expression pattern. A type 1 IFN gene signature score ≥5.61 displayed high sensitivity (100%) and specificity (91%) for identification of active TB. Application of this score to QFT-positive patients with uveitis of unknown cause yielded two groups with expected different likelihood (high vs. low) of having active-TB uveitis, and therefore may be useful in clinical management decisions.

[Ocular tuberculosis]

Despite extensive investigations, including the use of Interferon-gamma release assays (IGRA), the diagnosis of intraocular tuberculosis (TB) remains challenging. Ocular evidence of Mycobacterium tuberculosis in low endemic countries for TB is extremely rare, leading mostly to a TB-related ocular inflammation presumptive diagnosis. This present work aims: to highlights the main clinical patterns suggestive of ocular TB; and the latest recommended guidelines for diagnosing ocular TB to clarify interferon-gamma release assay (IGRA) contribution and accuracy to the management of intraocular TB and its diagnosis, in addition to other available diagnostic tools, such as tuberculin skin test, bacteriologic and histologic analysis from intra/extra ocular sample and radiographic investigations; to define the accuracy of these diagnostic tools according to the endemic TB prevalence; and finally to identify therapeutic strategies adapted to the main clinical presentations of ocular TB. Our review of the literature shows that management of suspected ocular TB differs significantly based on whether patients are from high or low TB prevalence countries since accuracy of chest X-ray, tuberculin skin test and IGRA is significantly different. Taking into account these discrepancies, distinct guidelines should be determined for managing patients with suspected ocular TB, taking into consideration home prevalence of TB-patients.

[Ocular tuberculosis : A case series]

OBJECTIVES

Ocular tuberculosis is a rare form of extra pulmonary tuberculosis. It represents 1-2% of all clinical forms. The aim of this work was to focus on diagnostic and therapeutic characteristics of ocular tuberculosis.

METHODS

We report a case series of 14 patients with ocular tuberculosis seen in an infectious diseases department between 2006 and 2015. The diagnosis was retained on clinical data and a positive tuberculin skin test or interferon-gamma release assay.

RESULTS

The patient's mean age was 40.7±9years. The most common clinical presentation was uveitis (11 patients and 16 eyes). An extra ocular involvement was associated in three patients. The mean duration of antitubercular therapy was 10±2.5 months. Corticosteroid therapy was associated in 11 cases. The outcome was favorable in all cases. Two patients had maintained visual sequelae.

CONCLUSION

Ocular tuberculosis is a rare disease but still remains a diagnostic problem. It should be considered in case of any chronic ocular symptoms, especially in endemic countries. Early management can improve the visual prognosis.

Tuberculosis and other causes of uveitis in Indonesia

PurposeThe purpose of this study is to assess the causes of uveitis in Indonesia and determine the importance of tuberculosis (TB) as a cause of uveitis.Patients and methodsProspective cohort study examining 146 consecutive new human immunodeficiency virus-negative patients with active uveitis between June 2014 and May 2015. We assessed the anatomic locations and specific causes of uveitis, as well as associations with infectious and non-infectious systemic diseases. We determined the prevalence of positive QuantiFERON Tb Gold test (QFT) results in Indonesian patients with uveitis and calculated the number of patients with active systemic TB.ResultsPosterior and panuveitis were the most common anatomic entities (38% each). Infections represented the most frequent cause of uveitis (33%); the most prevalent were toxoplasmosis (19%) and active systemic TB (8%). The majority of patients were QFT positive (61%). A specific diagnosis could not be established in 45% of the patients. At first presentation to the ophthalmologist, the majority of patients (66%) had a visual acuity of less than finger counting at 3 m and already exhibited various complications of uveitis. When classifying the QFT-positive patients with unexplained uveitis into a TB-related group, the percentage of 'TB-associated' uveitis cases increased from 8-48%. Highly elevated QFT levels were observed in patients with uveitis of unknown cause and no signs of active systemic TB.ConclusionsIn Indonesia, infectious uveitis was the most common type of uveitis and the leading causes consisted of toxoplasmosis and TB. The association observed between highly elevated QFT results and uveitis of otherwise unexplained origins indicates that a link exists between the latent TB infection and the development of uveitis.

[Anterior uveitis]

Anterior uveitis is the most common form of uveitis. There are several known and many possible etiologies for anterior uveitis. After examining the posterior segment and ruling out masquerade syndromes, the main step of etiologic diagnosis is clinical characterization. It is essential to establish unilateral versus bilateral involvement and presence or absence of granulomatous features. Subsequently, a work-up may be obtained which then helps to confirm diagnostic hypotheses based on the detailed history and clinical examination. The priority is to rule out an infection, although less frequent, before starting steroid therapy, adapted to the severity of the clinical picture. Finally, biologics have greatly changed the management and prevention of some forms of anterior uveitis, in particular uveitis associated with HLA-B27 and juvenile idiopathic arthritis-associated anterior uveitis.

Anterior uveitis

Anterior Uveitis is the most common form of uveitis. There are several known and many possible etiologies for anterior uveitis. After examining the posterior segment and ruling out masquerade syndromes, the main step of etiologic diagnosis is clinical characterization. It is essential to establish the presence or absence of unilateral versus bilateral and granulomatous features. Subsequently, a directed work-up may be obtained which then helps to confirm diagnostic hypotheses based on the detailed history and clinical examination. The priority is to rule out an infection. Treatments are adapted according to etiology and disease severity. Finally, biologics have greatly changed the management and prevention of some forms of anterior uveitis, in particular uveitis associated with HLA-B27 and juvenile idiopathic arthritis-associated anterior uveitis.

What does IGRA testing add to the diagnosis of ocular tuberculosis? A Bayesian latent class analysis

BACKGROUND

To evaluate the contribution made to the diagnostic work-up for patients with suspected ocular tuberculosis (TB) by QuantiFERON-TB Gold In-Tube (QFT) tests using latent class analysis model.

METHODS

A single centre retrospective cohort study. A Bayesian latent class model was constructed on the basis of demographics, phenotypes and test results from patients attending a tertiary referral center in the UK. This estimated the probability of ocular TB for each patient in two versions, first with and then without QFT. The estimated probability of ocular TB was compared with treatment failure.

RESULTS

From a database of 365 patients with clinical signs suggestive of ocular TB, 267 patients who had QFT and complete data were evaluated. Mean age was 45.0 ± 15.4 years with 141 (52.9%) male and 148 (50.5%) of Asian ethnicity. QFT was positive in 208 (70.1%) patients and ATT was instituted in 145 (49.5%) patients with 100 (34.1%) patients also having concurrent systemic corticosteroid therapy. The best estimate of a QFT level separating TB-positive and TB-negative patients was extremely low. This weak discrimination between TB and non-TB groups was reflected in poor positive and negative predictive values for treatment failure.

CONCLUSIONS

The latent class model did not successfully predict treatment failure, despite taking all variables into account. The threshold between TB and non-TB in QFT values was implausibly low and removing QFT from the model made prediction slightly worse. A larger prospective study is required to establish the role of all tests, demographics and phenotypes in diagnosis.

Clinical Features and Outcomes of Patients With Tubercular Uveitis Treated With Antitubercular Therapy in the Collaborative Ocular Tuberculosis Study (COTS)-1

Importance

Eradication of systemic tuberculosis (TB) has been limited by neglected populations and the HIV pandemic. Whereas ocular TB often presents as uveitis without any prior evidence of systemic TB, the existing uncertainty in the diagnosis of TB uveitis may perpetuate missed opportunities to address systemic TB.

Objective

To examine the clinical features of TB uveitis and the associations with response to antitubercular therapy (ATT).

Design, Setting, and Participants

This retrospective multinational cohort study included patients from 25 ophthalmology referral centers diagnosed with TB uveitis and treated with ATT from January 1, 2004, through December 31, 2014, with a minimum follow-up of 1 year.

Main Outcomes and Measures

Treatment failure, defined as a persistence or recurrence of inflammation within 6 months of completing ATT, inability to taper oral corticosteroids to less than 10 mg/d or topical corticosteroid drops to less than 2 drops daily, and/or recalcitrant inflammation necessitating corticosteroid-sparing immunosuppressive therapy.

Results

A total of 801 patients (1272 eyes) were studied (mean [SD] age, 40.5 [14.8] years; 413 [51.6%] male and 388 [48.4%] female; 577 [73.6%] Asian). Most patients had no known history (498 of 661 [75.3%]) of systemic TB. Most patients had bilateral involvement (471 of 801 [58.8%]). Common clinical signs reported include vitreous haze (523 of 1153 [45.4%]), retinal vasculitis (374 of 874 [42.8%]), and choroidal involvement (419 of 651 [64.4%]). Treatment failure developed in 102 of the 801 patients (12.7%). On univariate regression analysis, the hazard ratios (HRs) associated with intermediate uveitis (HR, 2.21; 95% CI, 1.07-4.55; P = .03), anterior uveitis (HR, 2.68; 95% CI, 1.32-2.35; P = .006), and panuveitis (HR, 3.28; 95% CI, 1.89-5.67; P < .001) were significantly higher compared with posterior distribution. The presence of vitreous haze had a statistically significant association (HR, 1.95; 95% CI, 1.26-3.02; P = .003) compared with absence of vitreous haze. Bilaterality had an associated HR of 1.50 (95% CI, 0.96-2.35) compared with unilaterality (HR, 1 [reference]), although this finding was not statistically significant (P = .07). On multivariate Cox proportional hazards regression analysis, the presence of vitreous haze had an adjusted HR of 2.98 (95% CI, 1.50-5.94; P = .002), presence of snow banking had an adjusted HR of 3.71 (95% CI, 1.18-11.62; P = .02), and presence of choroidal involvement had an adjusted HR of 2.88 (95% CI, 1.22-6.78; P = .02).

Conclusions and Relevance

A low treatment failure rate occurred in patients with TB uveitis treated with ATT. Phenotypes and test results are studied whereby patients with panuveitis having vitreous and choroidal involvement had a higher risk of treatment failure. These findings are limited by retrospective methods. A prospectively derived composite clinical risk score might address this diagnostic uncertainty through holistic and standardized assessment of the combinations of clinical features and investigation results that may warrant diagnosis of TB uveitis and treatment with ATT.

Review of people with retinal vasculitis and positive QuantiFERON®-TB Gold test in an area nonendemic for tuberculosis

PURPOSE

To assess the frequency of a positive QuantiFERON^®-TB Gold test (quantiferon) among patients with retinal vasculitis in an area nonendemic for tuberculosis (TB); to review clinical characteristics and management of affected individuals.

METHODS

Consecutive patients with retinal vasculitis and a positive quantiferon were retrospectively analyzed. Demographics, clinical data, laboratory, imaging findings, and therapy were evaluated.

RESULTS

Among 49 patients with retinal vasculitis, 12 (24%) had a positive quantiferon. Median age was 37 years, there were five female patients. Five individuals (42%) had previously lived in a country endemic for TB. Retinal vasculitis was occlusive in six patients (50%). On chest imaging, pulmonary tuberculosis was suspected in one patient (8.3%). Treatment modalities included full antitubercular treatment (n = 1), isoniazid prophylaxis (n = 6), systemic corticosteroids (n = 8), and laser treatment (n = 5). After a median follow-up of 27.5 months, inflammation was inactive (n = 6) or recurrently present (n = 6). No patient lost ≥ 2 lines of best-corrected visual acuity during follow-up.

CONCLUSIONS

The quantiferon test is recommended in the evaluation of people with retinal vasculitis. Interpretation of a positive result can be challenging in a country nonendemic for TB. The majority of patients with quantiferon-positive retinal vasculitis were found to have latent TB.

The efficacy of latent tuberculosis treatment for immunocompetent uveitis patients with a positive T-SPOT.TB test: 6-year experience in a tuberculosis endemic region

PURPOSE

To assess the efficacy of latent tuberculosis (TB) treatment for immunocompetent uveitis patients with a positive T-SPOT.TB test.

METHODS

This is a consecutive case series of all T-SPOT.TB positive latent TB patients with presumed tuberculous uveitis managed with anti-tuberculous therapy (ATT) from 1 January 2000 to 31 December 2015. Patients with active TB or other known causes of uveitis, immunocompromised states and those followed up < 12 months were excluded. Descriptive statistics and hypothesis testing were performed, with a significance level of p < 0.05 taken.

RESULTS

Among the 75 T-SPOT.TB tests performed for uveitis, 14 cases were enrolled. Mycobacterium tuberculosis was isolated in none of the sputum and intraocular samples. Most cases had posterior uveitis (10/14 cases, 71.4%) and/or intermediate uveitis (9/14 cases, 64.3%). Vasculitis was predominantly occlusive. The mean presenting best-corrected visual acuity (BCVA) was 0.18, improving to 0.44 at 6 months (p = 0.03) and 0.40 at 12 months. (p = 0.03). At 1 year, remission of uveitis was achieved in 92.9%, in which none of them recurred at the last follow-up. High-dose systemic steroid was required in 50% of patients. Only 1 patient was steroid dependent at 18 months. The BCVA improvement in patients treated with or without steroid was comparable.

CONCLUSION

In a TB-endemic region with wide Bacille Calmette-Guerin vaccination coverage, ATT for immunocompetent uveitis patients with latent TB identified from T-SPOT.TB test can improve vision, induce long-term steroid-free remission, and prevent recurrence and systemic reactivation of TB in those who require steroid.

The Role of QuantiFERON®-TB Gold and Tuberculin Skin Test as Diagnostic Tests for Intraocular Tuberculosis in HIV-Positive and HIV-Negative Patients in South Africa

PURPOSE

To compare QuantiFERON®-TB Gold and tuberculin skin testing as diagnostic tests for intraocular tuberculosis in HIV positive and negative patients.

METHODS

A prospective study evaluating two different tests to help diagnose intraocular tuberculosis.

RESULTS

Thirty-five of 106 patients (33.0%) were diagnosed with intraocular tuberculosis including 11 (31.4%) with HIV infection. Patients were 6.95 times more likely to have intraocular tuberculosis if TST alone was positive (p < 0.001) versus 2.19 times more likely if Quantiferon alone was positive (p = 0.04). Tuberculin skin testing showed superior specificity (60.3% vs 33.3%) (p = 0.001) but similar sensitivity (90.3% vs 85.7%), positive (54.9% vs 40.5%) and negative predictive values (92.1% vs 81.5%) compared to Quantiferon. Specificity did not increase significantly if both skin testing and Quantiferon were positive.

CONCLUSIONS

In South Africa, with its high HIV burden and limited public health resources, Quantiferon testing should not replace tuberculin skin testing as it provides little additional diagnostic information.

An OCT Study of Anterior Nodular Episcleritis and Scleritis

Anterior scleritis and episcleritis are a well-known presentation in tuberculosis. The case of a female patient with presumed tuberculous anterior scleritis and episcleritis is discussed in this article. Anterior segment OCT was efficient in diagnosis and evaluation of the therapeutic outcome. Antituberculosis chemotherapy was sufficient to achieve clinical remission.

Latent tuberculosis-related scleritis: a case report

BACKGROUND

Scleritis is a painful inflammatory process centered in the sclera that may involve the cornea and the underlying uvea. The etiology is commonly idiopathic or autoimmune but some cases are associated with systemic infection such as tuberculosis.

CASE PRESENTATION

In this report, we describe an unusual case of a female Moroccan patient who had a long history of bilateral recurrent scleritis associated with peripheral keratopathy and anterior uveitis. The patient was diagnosed with latent tuberculosis and responded to antitubercular therapy administrated after exclusion of other aetiologies. This patient was finally diagnosed with latent tuberculosis- related scleritis.

CONCLUSIONS

Although systemic tuberculosis is reported as a possible cause of scleritis and other ocular inflammatory manifestations, assessment of the diagnosis of tuberculosis-related ocular inflammation is challenging especially in latent forms. The treatment is largely presumptive. However, a favorable response to antitubercular therapy without relapse is taken as evidence of the disease.

Diagnosis of Ocular Tuberculosis

Ocular tuberculosis remains a presumptive clinical diagnosis, as the gold standard tests for diagnosing ocular tuberculosis are often not useful: Mycobacterium tuberculosis cultures require weeks to process on Lowenstein-Jenson media and have low yield from ocular samples; while acid-fast bacilli smears or polymerase chain reaction detection of M. tuberculosis DNA have low sensitivities. Thus, diagnosis is often based on suggestive clinical signs, which are supported by positive investigations: tuberculin skin test or interferon-gamma release assays; chest X-ray findings suggestive of pulmonary tuberculosis, and/or evidence of associated systemic tuberculosis infections in the absence of other underlying disease. The aim of this review is to provide an update on the methods of diagnosing ocular tuberculosis, and discuss the challenges of its diagnosis. We also suggest a step-ladder approach to a more accurate diagnosis of ocular tuberculosis by combining the available diagnostic tests.

QuantiFERON-TB Gold Assay on Plasma for Confirmation of Presumed Tuberculosis-Related Uveitis

The QuantiFERON-TB Gold assay was used to measure interferon gamma levels in plasma from 4 patients with presumed tuberculosis-related uveitis before, during, and after antitubercular therapy. After treatment, all patients showed clinical improvement. The concentrations showed a reversion to an absence of interferon gamma in one case, decreased in two cases, and remained stable in one case. These results suggest that the QuantiFERON assay may be useful for tuberculosis-related uveitis diagnosis and follow-up.