Analysis of Viral Resistance in CMV Retinitis

描述（由申请方提供）：本申请用于分析巨细胞病毒（CMV）视网膜炎和病毒耐药性（CRVR）研究生成的数据。 CMV视网膜炎是艾滋病患者常见的机会性感染。 未经治疗的CMV视网膜炎是一种进行性感染，其最终结果是破坏视网膜和失明。 除非由于高效抗逆转录病毒治疗（HAART）而发生免疫重建，否则需要长期抑制性治疗以防止疾病复发。 据报道，抗CMV治疗9个月后，约25%的患者发生耐药CMV（由于UL 97或UL 54基因突变）。 血液或尿液中的耐药CMV与视网膜炎进展、视网膜面积丧失和视力丧失的风险显著增加相关。 在眼睛中检测到的CMV基因组几乎总是与在血液或尿液中检测到的相同。 视网膜炎的许多复发是由于有限的眼内药物渗透而不是耐药性，目前的做法通常是用相同的药物重新诱导患者，而不是转换药物，这种方法对耐药CMV无效。 如果确定耐药CMV，则将治疗改为替代药物。 目前用于鉴定携带耐药CMV的患者的方法需要培养和测试分离株的耐药性，这一过程可能需要10周。 为了使耐药检测达到临床实用性，需要更快速的方法来鉴定携带耐药CMV的患者;两种候选方法是：1）CMV病毒载量，和2）聚合酶链反应（PCR）扩增来自血液标本的CMV DNA并对其进行测序以获得赋予更昔洛韦耐药的突变。 CRVR研究是一项前瞻性研究，涉及309例AIDS和CMV视网膜炎患者，研究从血液或尿液中分离的耐药CMV的发生情况。 我们将使用CRVR研究产生的数据：1）评价CMV病毒载量，作为快速识别携带耐药CMV患者的方法; 2）评价血液标本中CMV UL 97基因的PCR和测序，作为快速识别携带对更昔洛韦耐药的CMV患者的方法; 3）评价HAART对耐药CMV发生率的影响。 我们的假设是：1）CMV病毒载量的增加将是携带耐药CMV的患者的标志物; 2）直接筛查血液中的CMV UL 97突变将鉴定携带更昔洛韦耐药CMV的患者;和3）在发生CMV视网膜炎然后开始HAART的患者中，耐药率将降低，但与治疗前相似。HAART时代发生在已经接受HAART治疗后发生CMV视网膜炎的患者中。 计划出版三份出版物：1）“CMV病毒载量作为CMV视网膜炎患者中耐药CMV的预测因子”; 2）“PCR扩增和测序来自血液标本的UL 97基因以鉴定CMV视网膜炎患者中的耐药CMV”;和3）“HAART对CMV视网膜炎患者中耐药CMV发生率的影响”。"

DESCRIPTION (provided by applicant): This application is for analyses of data generated by the Cytomegalovirus (CMV) Retinitis and Viral Resistance (CRVR) Study. CMV retinitis is a common opportunistic infection among patients with AIDS. Untreated CMV retinitis is a progressive infection, the end result of which is destruction of the retina and blindness. Unless immune reconstitution occurs as a consequence of highly active antiretroviral therapy (HAART), chronic, suppressive therapy is required to prevent relapse of the disease. Resistant CMV (due to mutations in the UL97 or UL54 genes) has been reported to occur in approximately25% of patients by 9 months of anti-CMV therapy. Resistant CMV in the blood or urine is associated with substantially increased risks of retinitis progression, loss of retinal area, and loss of visual acuity. The genome of CMV detected in the eye is nearly always identical to that detected in the blood or urine. Many relapses of retinitis are due to limited intraocular drug penetration rather than resistance, and current practice typically is to re-induce patients with the same drug rather than switch drugs, an approach which is ineffective for resistant CMV. If resistant CMV is identified, treatment is changed to an alternative drug. Current methods for identifying patients who harbor resistant CMV require culturing and testing isolates for resistance, a process which may take 10 weeks. In order for resistance testing to achieve clinical utility, more rapid methods for identifying patients who harbor resistant CMV are needed; two candidates are: 1) CMV viral load, and 2) polymerase chain reaction (PCR) amplification of CMV DNA from blood specimens and sequencing it for mutations conferring ganciclovir resistance. The CRVR Study is a prospective study of 309 patients with AIDS and CMV retinitis for the occurrence of resistant CMV isolated from either the blood or urine. We will use data generated from the CRVR Study to: 1) evaluate CMV viral load as a means to rapidly identify patients who harbor resistant CMV; 2) evaluate PCR and sequencing of the CMV UL97 gene from blood specimens as a means to rapidly identify patients who harbor CMV resistant to ganciclovir; and 3) to evaluate the effect of HAART on the incidence of resistant CMV. Our hypotheses are that: 1) increases in CMV viral load will be a marker for patients who harbor resistant CMV; 2) screening of blood directly for CMV UL97 mutations will identify patients who harbor ganciclovir-resistant CMV; and 3) that the rate of resistance will be decreased among patients who developed CMV retinitis and then were started on HAART but similar to that from the pre-HAART era among patients who develop CMV retinitis after already having been treated with HAART. Three publications are planned: 1) "CMV viral load as a predictor of resistant CMV among patients with CMV retinitis"; 2) "PCR amplification and sequencing of the UL97 gene from blood specimens to identify resistant CMV among patients with CMV retinitis"; and 3) "The effect of HAART on the incidence of resistant CMV among patients with CMV retinitis."