Preliminary Study On The Clinical Application Of IGRA On The Etiological Diagnosis Of Recurrent Uveitis With Unknown Etiology

Uveitis is a kind of common ophthalmic diseases which can result in blindness. Its etiology and pathogenesis are complex, and its diagnosis and treatment are difficult because the etiologies of numerous kinds of uveitis are still unknown. Hence, lots of uveitis recur a lot. The recurrence of uveitis leads to the damage of eyesight, even the loss of eyeball. The prevalence rate of tuberculosis in China is the second highest, only lower than that in India. Neverthless, the reported prevalence was low. It was mainly related to the diverse clinical manifestations and the absence of specificly diagnostic method. The inteferon-gamma release assay(IGRA) is a new method which is used to diagnose the tuberculosis internationally. The sensitivity and specificity of IGRA are higher than TST. It was suggested that the IGRA can be performed on the following two kinds of patients by NICE. Some of them were the patients who got the positive results of TST and the possibility of getting latent infection of tuberculosis. The rest of them were the patients who were in the immunocompromised situation. At the same time, it was recommended that IGRA was an available method in diagnosing latent infection of tuberculosis besides TST by CDC. And they have already adopted IGRA in the supervision of tuberculosis in replacement of TST. In China, it should be further examined that the application experience of the nations whose burden of tuberculosis is light. We carried out a preliminary study on the clinical application of IGRA on the etiological diagnosis of recurrent uveitis with unknown etiology in China. The purpose of the study was to discuss the significance of the IGRA on the clinical application, as the basis of further study. In the meantime, we clarified the manifestations of tuberculous uveitis, which can improve the diagnosis and treatment level of tuberculous uveitis.Objectives: To discuss the significance of IGRA on the etiological diagnosis of recurrent uveitis with unknown etiology. And to summarize the clinical manifestations.Methods: Firstly, we screened out 38 consecutive patients according to the inclusion and exclusion criteria. Secondly, all of the medical history in the scope of screening tuberculous uveitis were recorded. Thirdly, TST and IGRA were preformed on all the patients.To clarify, TST was performed in Mantoux method and IGRA was performed in TB-IGRA. Accepted by the patients with presumed tuberculosis uveitis, the dosage of glucocorticoid and immunosuppressant were reduced rapidly to drug withdrawal.Then the experimental ATT were performed on the patients with presumed tuberculosis uveitis, whose results of TST and IGRA were both positive. On the basis of the diagnostic criteria of tuberculous uveitis, the tuberculous uveitis was preliminary confirmed. Last but not lest, the clinical manifestations of patients with presumed tuberculous uveitis and preliminarily confirmed tuberculous uveitis were clarified.Results: 1 The medical history in the scope of screening tuberculous uveitis. Among 38 patients who were selected in the scope of screening tuberculous uveitis, there were 10 patients who had the contact history of tuberculosis, and the other 28 patients denied. 8 patients admitted the diagnosis and treatment history of tuberculosis. There were 6 patients with pulmonary tuberculosis and 2 patients with scrofula, while the other 30 patients denied. 5 of them admitted the history of prevention inoculation of BCG, and 33 patients denied. 25 patients had the history of glucocorticoid or immunosuppressant. Moreover, 3 patients got the disease of destroying immunity, and 10 patients were in absence of systemic disease. 2 The results of TST and IGRA which were performed on the patients who were in the scope of screening tuberculous uveitis. Among the 38 patients who were selected in the scope of screening tuberculous uveitis, there were 27 patients who got the positive results of TST,and 18 patients’ results of IGRA were positive. TST and IGRA both appeared positive results in 16 patients. While both of them turned negative in 9 patients. There were 2 patients who got positive results in IGRA and negative results in TST, and 11 patients had the opposite results. There is statistically significant difference(P = 0.022 < 0.05) between the positive rate of TST and IGRA. 3 The effect of experimental ATT in the light of the results of TST and IGRA. Accepted by the patients, the experimental ATT has been performed on 8 of 16 patients with presumed tuberculous uveitis whose results of TST and IGRA were both positive. Two of them recurred. One of them recurred when one and a half months after terminating glucocorticoid and immunosuppressant. And the other recurred when two and a half months after that. So the diagnosis of tuberculous uveitis was ruled out. The uveitis of the other 6 patients gradually vanished after terminating glucocorticoid and immunosuppressant. To our surprise, the uveitis hasn’t recurred in the following 3 months. The tuberculous uveitis was confirmed according to the criteria in our study. 4 The clinical classifications and manifestations of patients with presumed tuberculous uveitis and preliminarily confirmed tuberculous uveitis. 4.1 There were 16 patients with presumed tuberculous uveitis. 9 of them were male, 7 of them were female. 12 of them were bilateral, and 4 of them were monocular. There were 2 patients of anterior uveitis, 1 patient of intermediate uveitis, 8 patients of posterior uveitis and 5 patients of panuveitis. 4.2 There were 6 patients with preliminarily confirmed tuberculous uveitis, including 4 male and 2 female. 5 of them were bilateral, the other was momocular. Among them, there were 4 posterior uveitis and 2 panuveitis.The manifestations were mainly located in the posterior part, including 3 case with vitritis, 3 retinochoroiditis, 3 periphlebitis and 2 iris posterior synechia.Conclusion: To make the definite diagnosis of tuberculous uveitis is difficult. IGRA can make up the shortage that the high false positive rate of TST. All in all, IGRA may play certain role in the diagnosis of tuberculous uveitis.