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

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.

Diagnosis and treatment of tuberculosis presenting as uveitis based on stochastic simulation in systems biology

Tuberculous uveitis can be a manifestation of extrapulmonary tuberculosis or an allergic reaction to tuberculosis infection. The clinical signs and symptoms of other uveitis causes are generic, making a false diagnosis simple. We present a brief introduction to theoretical modelling and simulation in systems biology and explore the consequences of TB uveitis if left untreated. Patients were admitted to our hospital with recurrent fever. They had a previous definitive diagnosis of binocular uveitis and a positive interferon gamma release assay (IGRA) test result. At the time, there was no antituberculosis medicine available, and immunosuppressive and glucocorticoid therapy did not work. After the admission, their pleural fluid tested positive for Mycobacterium tuberculosis. No other causes to explain the fever were found. A diagnosis of tuberculosis was made, and their body temperature normalized after antituberculosis treatment and closed chest drainage. Vigilance should be exercised to rule out tuberculous uveitis in cases of unexplained uveitis; this calls for IGRA screening, tuberculin skin testing, and cyst imaging. For patients with latent tuberculosis infections, it is recommended to administer antituberculosis treatment, after excluding other possible causes, and to avoid using glucocorticoids in isolation.

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.

Treatment Outcome of Tubercular Uveitis in a High TB and HIV Setting: A Prospective Cohort Study

Purpose

To determine the time to resolution of inflammation in tubercular uveitis (TBU) cases on standard anti-tubercular treatment. Sub-analysis of time to resolution according to HIV status was also performed.

Patients and Methods

A prospective cohort study of presumed idiopathic uveitis cases >18 years underwent the tuberculin skin test, QuantiFERON-TB Gold test, and ocular tuberculosis (TB) polymerase chain reaction test. Adult TBU cases were treated with standard anti-tubercular therapy (and corticosteroids) for 9 months. Cases were followed-up for resolution of inflammation at 1.5, 3, 6, 9, 12 and 15 months post-diagnosis. Outcome measure was resolution of inflammation on ≤10 mg oral prednisone per day.

Results

Seventy-nine presumed idiopathic uveitis cases were enrolled in the study, 49 (62%) were diagnosed with TBU. The mean (SD) age of TBU cases at diagnosis was 41.8 (13.4) years. Using a multilevel mixed effects model, resolution was achieved at 6 months in the TBU cases (OR = 1.21; 95% CI, 1.03-1.41; P = 0.017). Using generalized estimating equations, resolution was also achieved at 6 months in the TBU cases (OR = 1.21; 95% CI, 1.05-1.39; P = 0.008). The HIV-positive cases (OR = 1.62; 95% CI, 1.13-2.31; P = 0.008) and the HIV-negative cases (OR = 1.25; 95% CI, 1.06-1.48; P = 0.009) achieved resolution at 9 months.

Conclusion

Resolution of inflammation in TBU cases on anti-tubercular treatment with corticosteroids was achieved at 6 months and maintained throughout the study. Our study suggests a minimum of 6 months treatment is required for significant resolution. Resolution of inflammation in HIV-positive and HIV-negative TBU cases needs to be further explored.

Global prevalence and clinical outcomes of tubercular uveitis: a systematic review and meta-analysis

Tubercular uveitis (TBU) is an inflammation/infection of the eye secondary to Mycobacterium tuberculosis infection. The difficulty in making the diagnosis has resulted in variable prevalence and clinical response rates. We aimed to determine the global prevalence of TBU in uveitis patients stratified by TB high-burden countries (HBCs) and non-HBCs and by geographic regions and the clinical response of TBU to antitubercular treatment We performed a systematic review and meta-analysis of TBU studies published in PubMed, Scopus and EMBASE, up to June 30, 2020. A random effects model was used for all meta-analyses. Of 5,018 articles identified, 70 prevalence studies (65,607 uveitis and 3,166 TBU cases) and 18 clinical outcome studies (1,570 TBU cases; 1,304 responded to anti-tubercular therapy [ATT]) were analyzed. The overall weighted prevalence of TBU was 4.0% (95% CI, 3-5); in TB HBCs it was 7.0% (95% CI, 5-11), non-HBCs 3.0% (95% CI, 2-4), and sub-Saharan Africa 11.0% (95% CI, 8-15). The overall weighted clinical response was 82.0% (95% CI, 75-89). Despite the difficulty in diagnosing TBU, the prevalence is expectantly higher in HBCs, and sub-Saharan Africa and the clinical outcome is poor. Standardization of diagnostic criteria and ATT is warranted in future cohort studies.

The clinical presentation and treatment outcomes of ocular tuberculosis: a 5-year experience in an endemic area

PURPOSE

To report the clinical presentations of ocular tuberculosis infection (OTB) and the treatment regimen and outcome in an endemic area.

METHODS

This is a retrospective case series of patients with presumed OTB treated in a tertiary teaching hospital in Hong Kong in 2014-2019.

RESULTS

Among the nineteen patients recruited, the most common clinical presentation of OTB was retinal vasculitis (42.1%), followed by scleritis, intermediate uveitis, and choroidal tuberculoma (15.8% respectively). 94.7% and 94.4% of the subjects were treated with ATT and steroid, respectively, and 31.6% were put on systemic immunosuppressant prior to the initiation of ATT. Apart from those suffering from intermediate uveitis, most demonstrated good clinical response within 8 weeks of ATT initiation.

CONCLUSION

Ocular involvement of TB has been increasingly recognized, especially in endemic regions like Hong Kong. High index of suspicion is recommended for OTB in typical clinical phenotypes or recurrent/resistant ocular inflammation unresponsive to conventional therapy. TB retinal vasculitis was the most common presentation of OTB in this study and OTB generally requires treatment with either regional or systemic steroid together with ATT.

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.

Uveitis associated with latent tuberculosis: A comparative study of the impact of antitubercular therapy combined or not with systemic corticosteroids

PURPOSE

To study the outcome of latent tubercular uveitis (LTBU) treated with antitubercular therapy (ATT) combined or not with adjuvant systemic corticosteroids.

METHODS

Twenty patients (27 eyes) with LTBU were included in a monocentric retrospective study and evaluated for the absence of active disease after treatment. Data on the clinical outcomes (active inflammation), vision (best-corrected visual acuity, BCVA) and treatment were collected retrospectively.

RESULTS

Fourteen patients received ATT alone and six patients received ATT combined with systemic corticosteroids. The two groups were not comparable in terms of proportion of tubercular panuveitis cases and initial BCVA (59.3 ± 8.2 letters vs 44.2 ± 15.2 letters). There was no significant difference in remission rate and in BCVA between both groups 3 months after ATT discontinuation.

CONCLUSION

Patients with LTBU treated with ATT alone had visual and inflammatory outcomes at least comparable to those of patients treated with ATT combined with systemic corticosteroids.

The Collaborative Ocular Tuberculosis Study (COTS)-1: A Multinational Review of 165 Patients with Tubercular Anterior Uveitis

PURPOSE

The Collaborative Ocular Tuberculosis Study (COTS) Group sought to address the diagnostic uncertainty through retrospective cohort analysis of treatment regimens and therapeutic outcomes for patients with tubercular Anterior Uveitis (TAU) across international centers.

METHODS

Multicentre retrospective analysis of patients diagnosed with TAU between January 2004 to December 2014 that had a minimum follow-up of 1 year.

RESULTS

One hundred and sixty-five patients were included. One hundred and seven subjects received antitubercular therapy (ATT) (n = 107/165; 64.9%) with all the patients receiving topical steroid therapy. Treatment failure was noted in 17 patients (n = 17/165; 10.3%), more frequently described in patients that received ATT (n = 13/107, 12.2%), than those that did not receive ATT (n = 4/58, 6.9%).

CONCLUSION

In this retrospective study, addition of ATT did not have any statistically significant impact on outcome in patients with TAU.

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.