Presumed tuberculosis-associated uveitis: rising incidence and widening criteria for diagnosis in a non-endemic area

Evaluating Truenat Assay for the Diagnosis of Ocular Tuberculosis and Detection of Drug Resistance

BACKGROUND

Truenat MTB Plus assay was evaluated for diagnosing ocular tuberculosis (OTB) and detecting multi-drug resistant (MDR) and extremely-drug resistant (XDR) OTB.

METHODS

A total of 75 vitreous fluid specimens [five confirmed OTB, 40 clinically suspected OTB and 30 controls] were subjected to Truenat MTB Plus, multiplex PCR, and Xpert Ultra. Chips of Truenat were used for detecting rifampicin, isoniazid, fluoroquinolone and bedaquiline resistance. The performance was compared against culture, composite reference standard, and gene sequencing.

RESULTS

The overall sensitivity of TruePlus, MPCR, and Ultra in diagnosing OTB was 66.6%, 73.3%, and 55.5%, respectively. Out of six cases with mutations in rpoB gene, RifR was detected in five by TrueRif and four by Ultra. Three MDR and one XDR-OTB were reported by Truenat.

CONCLUSION

Truenat assay along with its strategic chips is a rapid and reliable tool for diagnosis of OTB and detection of drug resistance, including MDR and XDR-OTB.Abbreviations: OTB: Ocular tuberculosis; XDR: Extremely drug resistant; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF; PCR: polymerase chain reaction; NAATs: Nucleic acid amplification tests; MDR: Multi Drug Resistant; NSP: National Strategic plan for elimination of tuberculosis; FqR: Fluoroquinolone resistant; BdqR: bedaquiline resistant; TrueRif: Truenat MTB Rif Dx; TruePlus: Truenat Plus; INH: Isoniazid; DST: Drug susceptibility testing; MGIT: Mycobacterial growth indicator tube; CRF: Composite reference standard; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.

Comparative Evaluation of GeneXpert MTB/RIF Ultra and GeneXpert MTB/RIF for Detecting Tuberculosis and Identifying Rifampicin Resistance in Pars Plana Vitrectomy Samples of Patients with Ocular Tuberculosis

BACKGROUND

Xpert MTB/RIF Ultra (Ultra) was evaluated for the first time on Ocular tuberculosis (OTB) samples and compared with Xpert.

METHODS

Seventy five vitreous fluid samples (3 confirmed OTB, 47 clinically suspected OTB, and 25 controls) were subjected to Ultra, Xpert and Multiplex-PCR and compared against culture, composite reference standard (CRS), and gene sequencing.

RESULTS

The sensitivity of Ultra was 50% in diagnosing OTB (100% against culture and 46.8% against CRS). The overall sensitivity of Xpert and MPCR was 16% and 72%, respectively. Xpert missed three culture-positive cases and MPCR detected additional 11. Ultra and Xpert missed two and four cases of RifR, respectively. A total of 13(59%) cases were reported 'trace' by Ultra in which RifR could not be evaluated.

CONCLUSION

Ultra outperformed Xpert in diagnosing OTB. The advantage of Ultra's simultaneous RifR detection is lost since the trace bacterial loads in the specimens cause indeterminate results of RifR testing.Abbreviations: OTB: Ocular tuberculosis; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF, MPCR: multiplex polymerase chain reaction; NAATs: Nucleic acid amplification tests; MLAMP: multitargeted loop-mediated isothermal amplification; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.

Changing Trends in Uveitis in the United Kingdom: 5000 Consecutive Referrals to a Tertiary Referral Centre

PURPOSE

To demonstrate changes in the demography and diagnosis of uveitis in a specialist clinic in the United Kingdom.

METHODS

Retrieval of data including all new referrals to Manchester Uveitis Clinic from 1991 to 2020. The incidence and proportions of diagnoses between 4 quartiles was compared.

RESULTS

5000 patients with uveitis were seen. Referral rates trebled over time. Highly significant increases in referrals were seen for multiple evanescent white dot syndrome-spectrum disorders, syphilis and tuberculosis; increases were also seen for herpetic retinitis, vitreoretinal lymphoma and sarcoidosis. Highly significant decreases were seen for Fuchs' uveitis, Behçet's uveitis and ocular toxoplasmosis.

CONCLUSIONS

Subspecialisation and de-skilling has changed referral patterns to specialist clinics; changes cannot be entirely attributed to disease incidences, which also vary between countries. International data are non-comparable. There are clear changes in referral patterns and disease incidence in this population, influenced by evolving diagnosis. Local data should steer care planning.

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 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.

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.

Analysis of new cases of uveitis at academic and community settings

PURPOSE

Describe the demographics of new patients with uveitis presenting to an urban, academic centre and affiliated, suburban satellite clinics to assess if changes in infrastructure were needed for clinical care. Secondarily, examine the frequency of infectious uveitides.

METHODS

A retrospective chart review of single academic centre of 436 consecutive, new patients with uveitis (686 eyes) and 3 affiliated, satellite clinics seen by 8 uveitis specialists from 1 July 2013 to 31 March 2017. Demographics recorded included patient age, race, associated systemic disease, uveitis chronicity, and anatomic location. The main outcome measure was comparing frequencies of patient demographics, immunosuppressive agent use, and infectious uveitis between locations.

RESULTS

366 patients (587 eyes) were evaluated at the academic clinic and 70 (99 eyes) at the satellite locations. Anterior uveitis was the most common anatomic location; more acute, unilateral cases were seen at satellites (p=0.007; p=0.002, respectively). A larger percentage of posterior and panuveitis cases presented to the academic centre (p<0.0001). There was no difference in systemic disease association (p=0.925) or infectious uveitis cases (p=0.956). The use of non-corticosteroid immunosuppressive medications was higher at the academic clinic (p<0.001).

CONCLUSIONS

Anterior uveitis comprised the majority of cases in both clinics. Non-corticosteroid immunosuppressive agents were used more frequently at the academic clinic, reflecting more cases of chronic posterior and panuveitis. Compounded intravitreal injections, specialised ophthalmic imaging studies and high-risk medication monitoring can be centralised in the academic clinic. Infectious uveitis cases were seen at both locations, with an increase in syphilis diagnoses at the academic centre.

Prognostic factors for TB-associated uveitis in the Asia-Pacific Region: results of a modified Delphi survey

Background

Prognostic factors for TB-associated uveitis (TBU) remain mostly unknown, due to the challenges in interpretation of patient data. We present consensus list of prognostic factors for resolution of inflammation in TBU, by experts across the Asia-Pacific region.

Methods

We applied a modified Delphi technique to generate consensus on prognostic factors influencing the resolution of inflammation in TB-associated: anterior uveitis (AU), retinal vasculitis (RV), and multifocal serpiginoid choroiditis (MSC). The initial questionnaire was developed through a face-to-face meeting. Sixteen uveitis experts from eleven Asia-Pacific countries were included. A single investigator circulated the questionnaire electronically and received the responses. Participants scored each item on 4-point Likert scale, in three successive rounds. After each round, a number of items were reduced based on response, and summary of responses was provided to participants. At the end of Round 3, items were considered significant if they: (1) achieved a median ≥2, and interquartile range ≤1, and (2) ≥75% of the respondents agreed on whether the item was a positive or negative prognostic factor.

Results

Forty-two putative questionnaire items were considered. At the end of Rounds 3, 4, 9, and 8 items in AU, RV, and MSC, respectively, met significance criteria. These included duration of disease, previous corticosteroid/immunosuppressive therapy, co-existent HIV, disease-specific imaging features, multidrug resistant TB, and duration of anti-TB therapy.

Conclusions

Consensus were achieved on multiple ocular and systemic factors that influence resolution of inflammation in TBU. These will form the groundwork for validation in prospective clinical trials.

Presumed ocular tuberculosis in the United Kingdom: a British Ophthalmological Surveillance Unit (BOSU) study

Introduction

Ocular tuberculosis (TB) is an extrapulmonary manifestation of mycobacterium infection that most commonly presents as uveitis. This is the first prospective incidence study of presumed ocular tuberculosis performed in the United Kingdom (UK).

Method

New cases of ocular tuberculosis presenting to hospitals in the UK were prospectively ascertained between October 2016 and November 2017 with the aid of the British Ophthalmological Surveillance Unit (BOSU). Initial presentation data and 1-year follow-up data was collected using questionnaires.

Results

Forty-eight patients were recruited giving an overall incidence for ocular TB of 0.73 per million population per annum. The origin of birth for 71% of the patients was a non-UK country and 87.5% had their initial diagnosis of TB made by an ophthalmologist. The most common first line treatment was isoniazid, rifampicin, ethambutol and pyrazinamide which 71% of patients were treated with 60% of patients were commenced on a reducing course of oral steroids. At 1-year follow-up, 29 patients (83%) had complete resolution of active clinical signs. Mean best corrected visual acuity (BCVA) at presentation was +0.41 LogMAR(SD = 0.62), compared to +0.31 LogMAR (SD = 0.56) at 12-month follow-up.

Discussion

It is increasingly the responsibility of the ophthalmologist to diagnose ocular TB and although it remains a rare condition, consensus on diagnostic criteria and treatment is required. Increasing recognition and accessibility to gamma-interferon testing should enable earlier detection. Treatment with quadruple ATT treatment regimens for at least 6 months shows good clinical outcomes. However, it is still unclear whether steroid use is beneficial. Further large studies with longer follow-up would be warranted to answer these questions.

Epidemiology of Adult Uveitis in a Northern Ireland Tertiary Referral Centre

Uveitis is inflammation of the middle layer of the eye, called the uveal tract. It can be classified by anatomic location of the focus of inflammation inside the eye: intermediate, posterior or pan-uveitis. These types are less common than anterior uveitis (iritis), but more often have underlying aetiologies that require identification. Some aetiologies are infective, while others require systemic immunosuppression. Underlying aetiologies vary in different regions in the world, and so local data is important to guide clinicians. This study describes the aetiology of 255 cases of intermediate, posterior and pan-uveitis in adults. The most common non-infectious causes, after idiopathic, were sarcoid, Birdshot chorioretinopathy, demyelination-related and Behçet's, whereas toxoplasmosis and herpes simplex and zoster related retinitis were the common infectious causes. Neither age nor sex of the patient were related to aetiology.

Assessment of measurement methods of posterior inflammation in stromal choroiditis: the value of quantitative outcome measures versus the presently qualitatively based paradigm

PURPOSE

To assess posterior inflammation using a fluorescein (FA)/indocyanine-green angiography (ICGA) scoring system, and compare them to the presently recommended outcome measure, the standardization of uveitis nomenclature vitreous haze score (SUN-VH) in stromal choroiditis.

METHODS

This was a retrospective study on patients with a diagnosis of ocular sarcoidosis(OS), ocular tuberculosis(OT), Birdshot retinochoroiditis(BRC) and Vogt-Koyanagi-Harada disease(VKH) seen in the Centre for Ophthalmic Specialized Care, Lausanne, Switzerland. Angiography signs were quantified according to an established FA/ICGA scoring system. Vitritis was assessed using SUN-VH. Results were compared.

RESULTS

65 newly diagnosed patients (128 eyes) with stromal choroiditis were included. Angiographic scoring showed variable degrees of choroidal versus retinal involvement (87% for OS, 72% for OT, 62.5% for BRC and 100% for VKH). On the other hand, a mere 22 of 128 eyes (17%) showed a SUN-VH score ≥ 2 necessary for inclusion in clinical trials. Moreover, FA/ICGA values followed a normal distribution curve and presented inter-examiner variations greater than 1-SD in only 8.4% of cases. SUN-VH values' distribution was non-normal and showed inter-examiner discrepancies greater than 1-SD in 51.7% of cases.

CONCLUSION

This study highlights the precise measurement of global posterior inflammation achieved by a dual FA/ICGA scoring system in stromal choroiditis. In contrast, SUN-VH scale appears imprecise and inadequate, as only a minute percentage of the studied eyes could have been included in a clinical trial based on this criterion. To evaluate posterior intraocular inflammation meaningfully in stromal choroiditis, the use of dual FA/ICGA is strongly advised and should replace the presently recommended SUN-VH system.

Autoimmunity, Autoinflammation, and Infection in Uveitis

PURPOSE

To review the pathogenesis of uveitis in light of recent advances in our understanding of innate and adaptive immune responses and their regulation.

DESIGN

Perspective.

METHODS

Methods included a review of prevailing views on the pathogenesis of uveitis and an analysis of developments in immunology that impact on its conceptual basis, particularly the concept of immunologic tolerance and its loss in autoimmunity. Importantly, the role of infection in the pathogenesis of uveitis is evaluated.

RESULTS

The results comprise a reappraisal of the pathogenesis of anterior vs posterior uveitis in the context of the blood-retinal barrier and its relation to autoimmune, autoinflammatory, and infectious uveitis. Autoimmunity is seen as a possible cause of certain forms of uveitis but definitive proof is lacking. Autoinflammatory disease, involving activated innate immune mechanisms, is considered causative in a second set of uveitis conditions. A place for infection in uveitis generally is proposed within a unifying concept for the pathogenesis of uveitis.

CONCLUSION

Infection may be implicated directly or indirectly in many forms of noninfectious or undifferentiated uveitis. In addition to the growing recognition that foreign antigen, including reactivatable infectious agents, might hide within ocular tissues, the possibility that a dysregulated microbiome might generate T cells that cause immune-mediated ocular inflammation has now been demonstrated experimentally. An uncontrolled, overexuberant host immune response may cause continuing irreversible tissue damage even after the infection has been cleared.