A Study to Compare the Efficacy of Two Potential Diagnostic Assays: a Fluorescein Conjugated Monoclonal Antibody in Vivo Assay and Nested Real Time PCR Assay to Rapidly and Accurately Diagnose Herpes Simplex Keratitis.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 50
- 试验地点
- 3
研究概览
简要总结
The aim of this study is to compare the safety, specificity, sensitivity and ease of procedure of two potential diagnostic assays for HSV-1 detection in the cornea. Through the use of this new diagnostic assay, correct and early intervention would not only reduce corneal scarring from HSK, but it would also allow the initiation of appropriate treatment for HSV mimicking keratitis.
HSV-1 infection of the eye can result in corneal scarring and blindness. Early diagnosis of this condition and appropriate treatment is of utmost importance. Various ocular surface conditions can mimic herpetic keratitis in their clinical presentation and can result in diagnostic confusion. Inappropriate or delayed treatment of herpetic corneal disease results in increased morbidity.
In the UK at present clinical presentation is the mainstay of diagnosis. Unfortunately these cases often present to the most inexperienced clinical staff resulting in variability in diagnostic acumen. This often results in a delay or inappropriate diagnosis of herpetic keratitis. Laboratory techniques presently available to aid diagnosis are infrequently used in clinical practice. There are various reasons for their lack of use. Historically viral culture techniques were the mainstay of investigation but were slow, requiring weeks to provide a result. PCR is now replacing culture techniques and is relatively quick, reliable and sensitive. Many clinicians within the UK are still not fully informed of these advances and are therefore not utilizing these techniques to supplement clinical diagnosis.
We propose to investigate the use of topically applied fluorescent antibody against active replicating HSV-1 in a droplet form and real time PCR detection of the virus. If successful this should increase the potential diagnostic capabilities of GPs and other less experienced health care workers. Such tests should reduce variability in diagnosis and the dependency on experienced ophthalmologists to diagnose the condition.
详细描述
Strategy
Patients attending the Ophthalmology departments, who fulfil the criteria as outlined below in patient recruitment criteria, will be asked for written consent to volunteer for this study. Tears will be removed and stored in a sterile labelled eppendorf at -70 degrees C until further analysis. An impression cytology sample will be taken from the inflamed cornea and stored in viral transport medium and sent to the regional virology laboratory, Belfast for extraction and storage procedures. Blood samples will be taken and stored appropriately until the paired 3 month samples are available for antibody testing. Monoclonal antibody will be applied for the in vivo diagnosis of HSK as outlined below and viewed using an in vivo confocal microscope. Photographic evidence of the result will be recorded for each patient. Data for the nested real time PCR analysis and the monoclonal antibody test will be recorded separately by different individuals for each patient as the study progresses. Patient records will also be updated with the results of the tear and blood tests as the study progresses.
Recruitment Potential:
Over 200 eye patients in the RVH Belfast, over 300 patients in Bedford and over 600 patients in BMEC in Birmingham are treated each year with topical acyclovir for suspected HSV-1 infection. The number of patients treated within the community by GPs would significantly increase this number. The vast majority of these patients will have never had any laboratory confirmation of herpetic infection. The patient throughput through each hospital each year should enable adequate recruitment to this study over the three year period. This should ensure that the study is entirely viable from the perspective of patient numbers.
Patient numbers needed for a viable study
研究设计
- 研究类型
- Observational
- 时间视角
- Prospective
入排标准
- 年龄范围
- 16 Years 至 —（Child, Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients over the age of 16 years in which the cause of keratitis is difficult to diagnose and in which HSK has to be excluded will be enrolled for this study
排除标准
- •Immunosuppressed patients including patients treated with systemic steroids will be excluded