Detection of human cytomegalovirus myocardial involvement by polymerase chain reaction during systemic infection and correlation with pp65 antigenemia and DNAemia in infected heart recipients

The detection and clinical features of human cytomegalovirus infection in infants

The aim is to investigate the spectrum of disease in 378 infants with human cytomegalovirus infection. In these patients, 27.78% were systemic infection and 72.22% involved single organ infection. Hepatitis, thrombocytopenic purpura, pneumonia were predominant with 33.07%, 13.49%, 6.35% respectively. The rate of HCMV systemic infection in infants younger than 2 weeks was higher than in those older than 2 weeks. The gB genotype analysis in 107 cases showed 53 gBI, 20 gBII, 18 gBIII, 7 gBI+gBII, 5 gBI+gBIII and 4 gBII+gBIII. These results suggest that HCMV can infect multiorgan and has varietal clinic feature. The gBI genotype is most prevalent.

CMV and transplant-related coronary atherosclerosis: an immunohistochemical, in situ hybridization, and polymerase chain reaction in situ study

Accelerated graft coronary atherosclerosis is the main obstacle to long-term survival in patients who have had a heart transplant. A possible involvement of the human cytomegalovirus (HCMV) in this type of coronary atherosclerosis has been postulated by many authors but has not been definitively demonstrated. In an attempt to clarify the role of HCMV infection in the pathogenesis of this complication, we looked for in situ antigens or DNA of HCMV in 30 coronary artery segments obtained at necropsy from patients who had undergone orthotopic cardiac transplantation at the São Paulo Heart Institute. We tried to correlate these HCMV markers with the presence of inflammation and/or atherosclerosis in histologic sections. The patients were grouped as follows: GI, less than 170 days of graft survival and absent/mild atherosclerosis; GII, more than 170 days of graft survival and absent/mild atherosclerosis; GIII, more than 170 days of graft survival and severe/moderate atherosclerosis (170 days was the shortest graft survival time associated with atherosclerosis). The search for HCMV genome and antigens in the coronary artery sections was performed using immunohistochemistry, in situ hybridization, and polymerase chain reaction in situ techniques. Immunohistochemistry and in situ hybridization revealed no evidence of HCMV in all 30 cases. Polymerase chain reaction in situ revealed scarce HCMV-positive lymphocytes in two cases (one each from GI and GIII) located in the adventitial layer. These findings preclude a direct role for the HCMV in the pathogenesis of accelerated graft coronary atherosclerosis. However, the possibility of an indirect effect of the virus, such as an immune-mediated inflammatory response by the host that increases the expression of histocompatibility antigens, leading to tissue injury, cannot be excluded.

Cytomegalovirus PP65 antigenemia monitoring as a guide for preemptive therapy: a cost effective strategy for prevention of cytomegalovirus disease in adult liver transplant recipients

BACKGROUND

The aim of the study was to assess the incidence of cytomegalovirus (CMV) infection and disease in adult liver transplant recipients, using routine preemptive therapy guided by the pp65 antigenemia test.

METHODS

Antigenemia was monitored weekly after liver transplantation (OLTX) for the first 3 months, and once a month for another 3 months. CMV seronegative recipients were treated preemptively for the first positive antigenemia. Seropositive recipients were treated only when their antigenemia count reached a threshold of > or =100 positive cells per 200,000 leukocytes.

RESULTS

A total of 144 patients were included between June 1994 and April 1995, of which 137 (95%) were primary OLTX. The percentage of positive antigenemia and CMV disease was 55 and 8%, respectively. Seventy-eight (54%) patients were protocol-monitored for the entire follow-up (group 1) and received appropriate preemptive therapy, although 66 (46%) patients had protocol violation by having missed blood samples or blood drawn at unscheduled times (group 2). Using Cox's proportional hazards model, patients with a first antigenemia count of >11 leukocytes had a significantly higher rate of CMV disease compared to patients with an antigenemia count < or =11 leukocytes (RR = 7.3, 95% confidence interval = 2.2 to 24.5). In a multivariate Cox regression analysis, adjustments were made to control for: group 1 versus group 2, use of OKT3, and serology risk categories. This analysis showed that the relative rate of CMV disease was still significantly higher among patients with antigenemia count >11 leukocytes (adjusted RR = 4.9, 95% confidence interval = 1.3 to 18.1). The estimated cost of preemptive therapy was less than that of prophylaxis with i.v. (14-day course) or oral (90-day course) ganciclovir.

CONCLUSIONS

Preemptive therapy guided by pp65 antigenemia is a useful and cost effective strategy for prevention of CMV disease.

Quantitation of cytomegalovirus: methodologic aspects and clinical applications

Cytomegalovirus (CMV) is an important pathogen in transplant recipients and human immunodeficiency virus (HIV)-infected individuals. Major progress has been made in developing quantitative detection methods for CMV in recent years. Due to their high sensitivity, these assays can detect CMV early, and quantitation may be useful in predicting the patient's risk for disease and in monitoring the effect of antiviral therapy. This review discusses methodological aspects of currently used quantitative assays for CMV (i.e., viral culture techniques, antigen detection assays, DNA detection assays including PCR, branched-DNA assay, and the DNA hybrid capture assay) and addresses the correlation of systemic and site-specific CMV load and CMV disease in different populations of immunosuppressed patients as well as the response to antiviral treatment. To date, direct antigen detection and molecular techniques have largely replaced traditional culture-based techniques for CMV quantitation. In general, a high systemic CMV load is correlated with CMV disease. This correlation is strong in the HIV-infected population and in solid-organ transplant recipients but less clear in allogeneic marrow transplant recipients. Measuring the viral load at specific anatomic sites may be an alternative way to assess disease activity in situations where the systemic viral load correlates poorly with disease activity. A reduction of the systemic CMV load also correlates with a response to antiviral treatment, but more research is needed to evaluate the role of viral load as a surrogate marker for drug resistance. Due to the widespread use of quantitative CMV detection techniques to direct and monitor antiviral treatment, there is a great need for an assessment of the reproducibility of test results and better standardization of the assays.