Intravitreal bevacizumab in treatment of retinal neovascularization from tuberculous retinal vasculitis

Evaluation of off-label anti-vascular endothelial growth factor and steroid implant medication uses in macular edema due to retinal vein occlusion in Turkey

WHAT IS KNOWN AND OBJECTIVE

Retinal vein occlusion (RVO) is one of the most common causes of vision loss. Anti-vascular endothelial growth factor (anti-VEGF) drugs, ranibizumab and aflibercept, and corticosteroid implants are approved treatment options for RVO-related macular edema (ME) in Turkey. To the best of our knowledge, there is no data regarding the off-label use of these drugs for RVO in English literature. We aimed to evaluate the clinical and demographic characteristics of off-label drug use applications in Turkey for RVO.

METHODS

Applications made to the Turkish Medicines and Medical Devices Agency between January 1 and December 31, 2018, for the use of off-label drugs (ranibizumab, aflibercept, dexamethasone implant) for the diagnosis of RVO from hospitals across Turkey were retrospectively analysed. Data of the applications, such as demographic characteristics, previous treatment regimens, reasons for applications, applicant hospitals and their regions, were recorded.

RESULTS

There were 291 approved applications for RVO. The mean age of the patients was 64.88 ± 10.78 years, 48.8% were male, and 51.2% were female. Of these applications, 44.7% were for aflibercept, 35.7% for ranibizumab and 19.6% for dexamethasone implant. No application was made for bevacizumab since it could be used without needing for an application. The most common reasons for applications were due to dose limitations, failure to complete loading doses, and glaucoma, respectively. In terms of the distribution of the applicant hospitals, public university hospitals ranked first with 72.5%, training and research hospitals ranked second with 14.7% and foundation university hospitals ranked third with 13.1% rates.

WHAT IS NEW AND CONCLUSION

The practice of drug use in RVO in Turkey has changed as of the beginning of 2019. Stepwise therapy has been accepted by the drug regulatory agency Turkish Medicines and Medical Devices Agency. Utilization of licensed drugs, aflibercept, ranibizumab and dexamethasone has been allowed only after administration of 3 doses of intravitreal bevacizumab. After 3 doses of bevacizumab, the physician may continue either with bevacizumab again or a dexamethasone implant. If there is a reason such as the presence of glaucoma, the physician may skip dexamethasone and switch to aflibercept and ranibizumab, but in this case, dexamethasone cannot be administered to the patient for life. The evaluation of the off-label treatments of RVO, which is one of the most frequently followed diseases in retina clinics, not only contributes to the literature but also provides information regarding the most frequently applied treatments and the physicians' off-label drug preferences for RVO.

Targeting Molecular Inflammatory Pathways in Granuloma as Host-Directed Therapies for Tuberculosis

Globally, more than 10 million people developed active tuberculosis (TB), with 1.4 million deaths in 2020. In addition, the emergence of drug-resistant strains in many regions of the world threatens national TB control programs. This requires an understanding of host-pathogen interactions and finding novel treatments including host-directed therapies (HDTs) is of utter importance to tackle the TB epidemic. Mycobacterium tuberculosis (Mtb), the causative agent for TB, mainly infects the lungs causing inflammatory processes leading to immune activation and the development and formation of granulomas. During TB disease progression, the mononuclear inflammatory cell infiltrates which form the central structure of granulomas undergo cellular changes to form epithelioid cells, multinucleated giant cells and foamy macrophages. Granulomas further contain neutrophils, NK cells, dendritic cells and an outer layer composed of T and B lymphocytes and fibroblasts. This complex granulomatous host response can be modulated by Mtb to induce pathological changes damaging host lung tissues ultimately benefiting the persistence and survival of Mtb within host macrophages. The development of cavities is likely to enhance inter-host transmission and caseum could facilitate the dissemination of Mtb to other organs inducing disease progression. This review explores host targets and molecular pathways in the inflammatory granuloma host immune response that may be beneficial as target candidates for HDTs against TB.