Recent developments in gene therapy research in India

Inherited genetic disorders are progressive in nature and lead to organ dysfunction or death in severe cases. At present, there are no permanent treatment options for >95% of inherited disorders. Different modes of inheritance, type of gene(s) involved, and population-based variations add further complexity to finding suitable cures for approximately 400 million patients worldwide. Gene therapy is a very promising molecular technique for the treatment of rare genetic disorders. Gene therapy functions on the basis of restoration, replacement, inhibition, and, most recently, editing of gene(s) to rescue the disease phenotype. Recent reports show that increasing numbers of gene therapy clinical trials are using viral vectors (64.2%) when compared with non-viral vectors. Rapid development of efficient viral vector systems like the adeno-associated virus (AAV) and lentivirus has significantly contributed to this progress. Notably, AAV-mediated gene therapy has shown high potential for genetic disease treatment as evident from recent clinical trials for the eye (NCT00999609), blood (NCT00979238), and neuro-muscular systems (NCT02122952). Safety and efficacy are the two most critical features required for vector(s) to qualify for pre-clinical and clinical trial approval. The process of clinical-grade vector production, evaluation, and approvals for gene therapy products requires significant technological development, knowledge enhancement, and large financial investments. Additionally, trained manpower is required to meet the demands for constant technical innovation. These factors together contribute towards exorbitant prices for every dose of a gene therapy product and thus pose a challenge for the gene therapy field. The Indian subcontinent has traditionally lagged behind North America, Europe, Japan, and others in gene therapy clinical trials due to factors like inadequate industrial-scientific infrastructure, lack of accessible and organized patient databases, low financial investments, etc. However, over the last decade, increasing awareness of rare diseases, and international approvals of gene therapies such as Luxturna, Zolgensma, Hemgenix, etc., have spurred gene therapy development in India as well. In view of these advances, this article outlines gene therapy research, regulatory processes, and the launch of gene therapy clinical trials in India in the context of major developments worldwide. We briefly describe ongoing gene therapy research across Indian organizations and the nascent gene therapy product manufacturing. Further, we highlight the various initiatives from the medical and patient community to avail rehabilitation and gene therapy options. We briefly discuss the roles of regulatory agencies and guidelines for gene therapy clinical trials in India. We anticipate that this concise review will highlight the promise of gene therapy for the large population of rare disease patients in India.

Coronavirus disease 19 (COVID-19) and viral keratouveitis – unraveling the mystery

To demonstrate viral proteins/inflammatory cytokines in a patient with unilateral keratouveitis. Retrospective case report. A 70-year-old Asian-Indian male presented with acute onset of blurring of vision in the left eye (OS) of 2 days duration. He had was coronavirus disease 2019 (COVID-19)-positive 3 months earlier. He had undergone cataract surgery/retinal laser photocoagulation in both the eyes. The corrected distance visual acuity (CDVA) (Snellen) in the right eye (RE) (OD) and left eye (LE) (OS) was 20/20 and 20/80, respectively. OS showed decreased corneal sensation, Descemet’s folds, mild stromal edema, and fine and pigmented keratic precipitates with anterior chamber 1+ flare and 1+ cells. Fundus evaluation showed scattered laser marks in the OD and temporal sectoral laser marks in OS. He was diagnosed with viral keratouveitis in OS. Tear samples were collected on Schirmer’s strips and tear wash for mass spectrometry and cytokines, which had 368 and 451 viral proteins in the RE and LE, respectively, using nano liquid chromatography–mass spectrometry, which were more than controls. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and varicella zoster virus proteins were detected. Cytokine analysis using flow cytometer analysis showed higher inflammation in OS as compared to OD. The patient was treated with oral acyclovir and topical steroids and resulted in resolution of his keratouveitis. SARS-CoV-2 proteins were present in the tear sample 3 months after COVID-19. The presence of viral proteins does not indicate causality

Cold bandage contact lens use reduces post-photorefractive keratectomy or corneal collagen-crosslinking pain perception in patients

Purpose: To compare post?operative pain perception using bandage contact lens (BCL) stored at 2–8?C (Cold BCL, CL?BCL) or room temperature (23 – 25?C, RT?BCL) after photorefractive keratectomy (PRK) or corneal collagen?crosslinking (CXL) and determine status of nociception associated factors. Methods: In this prospective interventional study, 56 patients undergoing PRK for refractive correction and 100 keratoconus (KC) undergoing CXL were recruited following approval from the institutional ethics committee with informed consent. Patients undergoing bilateral PRK received RT?BCL on one eye and CL?BCL on the other. Pain was graded by Wong–Baker scoring on the first post?operative day (PoD1). Expression of transient receptor potential channels (TRPV1, TRPA1, TRPM8), calcitonin gene?related peptide (CGRP) and IL?6 was measured in cellular content from used BCLs collected on PoD1. Equal number of KC patients received RT?BCL or CL?BCL post?CXL. Pain was graded by Wong–Baker scoring on PoD1. Results: Pain scores on PoD1 were significantly (P < 0.0001) reduced in subjects receiving CL?BCL (Mean ± SD: 2.6 ± 2.1) compared to RT?BCL (6.0 ± 2.4) post?PRK. 80.4% of subjects reported reduced pain scores with CL?BCL. 19.6% reported no change or increased pain scores with CL?BCL. TRPM8 expression was significantly (P < 0.05) increased in BCL of subjects reporting reduced pain with CL?BCL compared to those who did not. Pain scores on PoD1 were significantly (P < 0.0001) reduced in subjects receiving CL?BCL (3.2 ± 2.1) compared to RT?BCL (7.2 ± 1.8) post?CXL. Conclusion: The simple approach of using a cold BCL post?operatively substantially reduced pain perception and could overcome post?operative pain?related limited acceptance of PRK/CXL.

Distinct gene expression profiles underlie morphological and etiological differences in pediatric cataracts

Purpose: Pediatric cataract is a major cause of preventable childhood blindness worldwide. Although genetic mutations or infections have been described in patients, the mechanistic basis of human cataract development remains poorly understood. Therefore, gene expression of structural, developmental, profibrotic, and transcription factors in phenotypically and etiologically distinct forms of pediatric cataracts were evaluated. Methods: This cross?sectional study included 89 pediatric cataract subjects subtyped into 1) prenatal infectious (cytomegalovirus, rubella, and combined cytomegalovirus with rubella infection), 2) prenatal non?infectious, 3) posterior capsular anomalies, 4) postnatal, 5) traumatic, and 6) secondary, and compared to clear, non?cataractous material of eyes with the subluxated lenses. Expression of lens structure?related genes (Aqp-0, HspA4/Hsp70, CrygC), transcription factors (Tdrd7, FoxE3, Maf, Pitx 3) and profibrotic genes (Tgf?, Bmp7, ?SmA, vimentin) in surgically extracted cataract lens material were studied and correlated clinically. Results: In cataract material, the lens?related gene expression profiles were uniquely associated with phenotype/etiology of different cataracts. Postnatal cataracts showed a significantly altered FoxE3 expression. Low levels of Tdrd7 expression correlated with posterior subcapsular opacity, whereas CrygC correlated significantly with anterior capsular ruptures. The expression of Aqp0 and Maf was elevated

Patient stratification using point of care biomarkers in dry eye disease

With changes in lifestyle, such as the increasing use of digital screens and rising demand for refractive surgery, dry eye disease has become increasingly prevalent in recent times. While we are equipped with a number of diagnostic modalities and a myriad of treatment forms, ranging from topical medication to procedural therapies, the condition remains an enigma in terms of varied patient satisfaction. An understanding of the molecular basis of a disease may open up new avenues in the customization of its treatment. We attempt to simplify this in the form of a stepwise protocol to incorporate biomarker assays in dry eye management.

Proteomic and gene expression patterns of keratoconus.

Keratoconus is a progressive corneal thinning disease associated with significant tissue remodeling activities and activation of a variety of signaling networks. However, it is not understood how differential gene and protein expression direct function in keratoconus corneas to drive the underlying pathology, ectasia. Research in the field has focused on discovering differentially expressed genes and proteins and quantifying their levels and activities in keratoconus patient samples. In this study, both microarray analysis of total ribonucleic acid (RNA) and whole proteome analyses are carried out using corneal epithelium and tears from keratoconus patients and compared to healthy controls. A number of structural proteins, signaling molecules, cytokines, proteases, and enzymes have been found to be deregulated in keratoconus corneas. Together, the data provide clues to the complex process of corneal degradation which suggest novel ways to clinically diagnose and manage the disease. This review will focus on discussing these recent advances in the knowledge of keratoconus biology from a gene expression and function point-of-view.