Polymerase chain reaction detection of cytomegalovirus DNA in peripheral blood leukocytes as a predictor of cytomegalovirus disease in HIV-infected patients

Cytomegalovirus disease in the era of highly active antiretroviral therapy (HAART)

Cytomegalovirus (CMV) infection was one of the most important opportunistic infections in HIV-infected patients before the introduction of highly active antiretroviral therapy (HAART), i.e. the combination of at least three antiretroviral drugs of different classes. Thereafter, life expectancy and quality of life increased dramatically with the persistent suppression of HIV viremia and a significant reduction in incidence of CMV disease. Nevertheless, evidence for a multitude of direct and indirect effects of CMV on HIV progression is accumulating. Even in the era of HAART, a considerable number of HIV-infected patients have a CD4 cell count below <100 mm(-3), which involves a high risk for CMV disease. The focus of the present review is on interpretation of test results, their predictive value for CMV disease, and guidance for the rational use of diagnostic assays in HIV-infected patients. Identification of patients at immediate risk for CMV disease may be accomplished by detection of CMV-DNA in leucocytes or plasma. Evidence is growing that CMV genotypes may be also relevant for the risk of CMV disease. Diagnosis of CMV disease requires in most instances demonstration of virus in biopsy specimen from the affected organ because presence of CMV in blood may not be causally related to symptoms observed. Clinical symptoms and patient characteristics are essential in the interpretation of laboratory test results and may guide the rational collection of clinical specimen and use of laboratory assays. As a consequence, a reliable diagnosis of CMV disease and early identification of patients at high risk for CMV disease requires an integrated interpretation of clinical and virological information.

Human herpesvirus 6 and cytomegalovirus infections in children with human immunodeficiency virus infection and cancer

AIM

Measure the prevalence of human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) infections in children and adolescents with HIV infection and malignancy.

METHODS

Semiquantitative polymerase chain reaction and serology were used to test for HHV-6 and CMV infections in 31 cases (HIV-infected children with cancer), 56 HIV controls (HIV-infected children without cancer) and 30 cancer controls (HIV-uninfected children with cancer).

RESULTS

In cases, HIV controls and cancer controls, HHV-6 DNA was detected in 29, 39 and 34%, respectively, and CMV DNA was detected in 13, 4 and 7%, respectively. Four cases (13%) and no HIV controls or cancer controls harbored HHV-6 subtype A (P = 0.014). In cases, HIV controls and cancer controls, the prevalence of HHV-6 antibodies was 58, 68 and 93%, respectively, and the prevalence of CMV antibodies was 71, 48 and 70%, respectively. HHV-6 seroprevalence was lower in cases than in cancer controls (P = 0.002), even with adjustments for age and CD4 concentrations; however, HHV-6 infection rates (presence of HHV-6 DNA and/or HHV-6 antibodies) were similar in all groups. Stratification showed that CMV infection was more common in younger patients (ages < 8 years) without severe immune suppression (CD4 concentration >200 cells/microl) than in HIV controls (odds ration, 10.343; 95% confidence interval, 1.65, 121.57). Geometric mean titers of serum anti-CMV antibodies, but not anti-HHV-6 antibodies, were higher in cases (1:71) than in HIV controls (1:33) (P = 0.005).

CONCLUSIONS

HHV-6 and CMV infections were common among children with HIV infection and cancer. CMV seropositivity also was associated with cancer in younger HIV-infected patients who did not have severe immune suppression. HHV-6A was detected only in HIV-infected children with cancer.

Prognostic factors of survival of HIV-infected patients with cytomegalovirus disease: Aquitaine Cohort, 1986-1997. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine (GECSA)

OBJECTIVE

To analyse survival of HIV-infected patients who developed cytomegalovirus (CMV) disease and to identify prognostic factors of their survival.

METHODS

Cases of CMV disease diagnosed in the Aquitaine Cohort of HIV-infected patients (n = 4297) during the 1986-1996 period, were reviewed using standardised definitions. Follow-up was extended to December 1997. Cox model was used to determine factors associated with survival after the initial manifestations of CMV disease, considering protease inhibitor (PI) prescription and anti-CMV treatment as time dependent covariates.

RESULTS

253 patients presented a CMV disease of which 221 (87.3%) died (median survival: 7 months). A better prognosis for survival was associated with: PI prescription [relative hazard (RH): 0.26; 95% confidence interval (CI): 0.11-0.59], anti-CMV treatment (RH: 0.37; CI: 0.25-0.54), CD4+ lymphocyte cell count > 50/mm3 (RH: 0.66; CI: 0.47-0.94) and absence of neoplasia (RH: 0.70; CI: 0.52-0.94) whereas the disseminated CMV disease worsened prognosis (RH: 1.83; CI: 1.20-2.80).

CONCLUSION

Antiretroviral treatment including PI, improved short-term prognosis of CMV disease regardless of its clinical manifestations.

Quantitative cytomegalovirus DNA level in the blood and its relationship to cytomegalovirus retinitis in patients with acquired immune deficiency syndrome

OBJECTIVE

A pilot study was performed to determine whether relationships exist between changes in a quantitative solution hybridization assay for cytomegalovirus (CMV) DNA in the blood and development of CMV retinitis, development of nonocular CMV disease, or reactivation of pre-existing CMV retinitis lesions.

DESIGN

Observational case series.

PARTICIPANTS

Two groups of human immunodeficiency virus-infected patients: 10 CMV antibody-positive patients with CD4+ T-lymphocyte counts of less than 50 ml and no CMV disease at baseline and 11 patients with CMV retinitis but no extraocular CMV disease at baseline.

INTERVENTION

Quantitative changes in leukocyte-associated CMV DNA levels were observed over time. Anti-CMV therapies were based on clinical findings only.

MAIN OUTCOME MEASURES

Development of CMV end-organ disease or change in activity of pre-existing CMV retinitis lesions was measured.

RESULTS

Among patients with no CMV disease at baseline, four had CMV disease develop during follow-up (three cases of CMV retinitis, one case of presumed CMV esophagitis); all had CMV DNA levels greater than 5000 genomes/ml before the onset of CMV disease. The remaining six patients had levels less than 5000 genomes/ml throughout follow-up (P = 0.05). Among patients with CMV retinitis at baseline, all whose CMV DNA blood levels rose more than tenfold had extraocular CMV disease or reactivation of CMV retinitis develop. Raised CMV DNA blood levels were not seen in every patient with clinical reactivation of CMV retinitis.

CONCLUSION

Elevated or rising CMV DNA blood levels appear to be associated with the development of CMV disease in individuals with low CD4+ T-lymphocyte counts. In patients with CMV retinitis, rising levels appear to be associated with the development of extraocular CMV disease or reactivation of CMV retinitis. Conversely, reactivation of CMV retinitis also may occur in the absence of changes in CMV DNA blood levels. Further studies are warranted to determine whether changes in CMV blood levels can be used as a guide for preemptive therapy to prevent reactivation of CMV retinitis lesions or to help choose between local and systemic therapy for management of reactivations.

Human immunodeficiency virus infection, Part II

The acceptance of highly active antiretroviral therapy (HAART) among patients and health care providers has had a dramatic impact on the epidemiology and clinical characteristics of many opportunistic infections associated with human immunodeficiency virus (HIV). Previously intractable opportunistic infections and syndromes are now far less common. In addition, effective antibiotic prophylactic therapies have had a profound impact on the risk of patients developing particular infections and on the incidence of these infections overall. Most notable among these are Pneumocystis carinii, disseminated Mycobacterium avium complex, tuberculosis, and toxoplasmosis. Nevertheless, infections continue to cause significant morbidity and mortality among patients who are infected with HIV. The role of HAART in many clinical situations is unquestioned. Compelling data from clinical trials support the use of these therapies during pregnancy to prevent perinatal transmission of HIV. HAART is also recommended for health care workers who have had a "significant" exposure to the blood of an HIV-infected patient. Both of these situations are discussed in detail in this article. In addition, although more controversial, increasing evidence supports the use of HAART during the acute HIV seroconversion syndrome. An "immune reconstitution syndrome" has been newly described for patients in the early phases of treatment with HAART who develop tuberculosis, M avium complex, and cytomegalovirus disease. Accumulating data support the use of hydroxyurea, an agent with a long history in the field of myeloproliferative disorders, for the treatment of HIV. Newer agents, particularly abacavir and adefovir dipivoxil, are available through expanded access protocols, and their roles are being defined and clarified.

Long-term predictive value of a single cytomegalovirus (CMV) DNA PCR assay for CMV disease in human immunodeficiency virus-infected patients

Universal prophylaxis with oral ganciclovir is not cost-effective for the prevention of cytomegalovirus (CMV) disease in human immunodeficiency virus infection. For a preemptive strategy to be considered, patients at highest risk for CMV disease need to be easily and accurately identified. In this study, the sensitivity, specificity, positive predictive value, and negative predictive value of a single CMV DNA PCR assay for the subsequent development of CMV disease were 0.75, 0.89, 0.75, and 0.89, respectively.

Monitoring for cytomegalovirus infection in organ transplant recipients: analysis of pp65 antigen, DNA and late mRNA in peripheral blood leukocytes

The use of sensitive and specific methods for rapid and reliable diagnosis is required due to the considerable impact of human cytomegalovirus (HCMV) in organ transplant recipients. For this purpose the demonstration of the presence of viral antigens in peripheral blood leukocytes (PMNLs) and of viral nucleic acids in the same cells or in sera would seem to be of valid support. The present study was designed to test pp65 antigen, HCMV DNA and HCMV late mRNA in order to provide clinical information for the management of the infection. Fifty solid organ recipients were monitored for six months after transplant. The data obtained from the various tests were analysed from the first evidence of HCMV infection revealed by positive antigenaemia and/or DNA-polymerase chain reaction (PCR). In 3 asymptomatic and in 7 symptomatic patients, PCR became positive 1-2 weeks before antigenaemia but PCR did not discriminate the clinical evolution of HCMV infection. The antigenaemia test well correlated to the development of viral infection being positive in all symptomatics and in 31, 2% of asymptomatics. The antigenic load > 100/2 x 10(5) positive cells was always associated with clinical signs of illness. The detection of late mRNA was more indicative of the virus replicative status in the follow-up of patients treated with ganciclovir. In some cases there was evidence, prior to the other two tests, the block of viral replication due to the antiviral therapy and in others the onset of HCMV infection relapse.

The pp65 antigenaemia test as a predictor of cytomegalovirus-induced end-organ disease in patients with AIDS

OBJECTIVE

To evaluate the predictive value of pp65 antigenaemia quantitative test for cytomegalovirus (CMV) end-organ disease in patients with advanced HIV infection.

DESIGN AND PATIENTS

A prospective study in AIDS patients or HIV-infected subjects with CD4 count < 150 x 10(6)/l or CD4 percentage < 10% was carried out. Patients with a history of CMV disease or positive viraemia or antigenaemia tests and subjects under anti-herpes suppressive therapy were excluded. Clinical, ophthalmoscopic, biochemical and virological (antigenaemia test) evaluations were performed at baseline and every 1-3 months until the onset of CMV end-organ disease.

SETTING

Institutional tertiary care centre.

RESULTS

Forty-nine patients were evaluable for this study. End-organ disease was observed in 13 patients, 11 with at least one positive test, two with persistently negative assays. Thirteen patients without CMV disease had at least one positive test, whereas 23 always had negative tests. The 12-month Kaplan-Meier estimate of the incidence of CMV disease in our population was 30.9% and was 75% in antigenaemia-positive subjects. The negative predictive value (NPV) of the test was 92%, and the positive predictive value (PPV) was 45.8%. However, the NPV of quantitative (> 20 cells) antigenaemia assay was 92.1% and the PPV was 90.9%.

CONCLUSIONS

The antigenaemia test is a quick, simple and easy to perform assay for diagnosing CMV infection. The NPV is fairly good, as is the PPV when the quantitative method (> 20 positive cells) is used. This test could be used as an alternative to polymerase chain reaction in order to select patients at higher risk of CMV disease who can be treated with pre-emptive anti-CMV therapy.

Cost-effectiveness of cytomegalovirus (CMV) disease prevention in patients with AIDS: oral ganciclovir and CMV polymerase chain reaction testing

OBJECTIVE

To perform a cost-effectiveness analysis of strategies to prevent cytomegalovirus (CMV) disease.

METHOD

Markov model and published data.

PATIENTS

Hypothetical HIV-infected patients with CD4 cell counts < or = 50 x 10(6)/l and positive CMV serologies.

INTERVENTIONS

Oral ganciclovir daily versus plasma CMV DNA polymerase chain reaction (PCR) testing every 3 months with oral ganciclovir for patients with positive tests.

OUTCOME MEASURES

The number of CMV disease cases prevented by the interventions, life expectancy, disease-free life expectancy, and the cost to extend life by 1 year.

RESULTS

Oral ganciclovir preventive therapy reduces the lifetime number of CMV disease cases by 50 per 1000 cohort, extends life expectancy by 5 days and disease-free life expectancy by 18 days, and costs US$ 1,762,517 per year of life extended. Periodic PCR testing reduces the lifetime number of CMV disease cases by eight per 1000 cohort, extends life expectancy by 1 day and disease-free life expectancy by 3 days, and costs US$ 495,158 per year of life extended. The prevention strategies could be acceptably cost effective only under a combination of optimistic assumptions and reduced costs.

CONCLUSIONS

Oral ganciclovir preventive therapy and periodic plasma testing for CMV PCR with oral ganciclovir for those with positive tests result in small benefits at great cost. They are not cost-effective prevention strategies for persons with advanced HIV infection and positive CMV serologies.

Cytomegalovirus disease presenting as a focal brain mass: report of two cases

OBJECTIVE AND IMPORTANCE

Although the differential diagnosis of intracranial lesions in patients who have tested positive for human immunodeficiency virus is extensive, toxoplasmosis, lymphoma, and progressive multifocal leukoencephalopathy comprise approximately 90% of such cases. Cytomegalovirus infection of the central nervous system may be difficult to diagnose and rarely presents as mass lesions revealed by radiographic studies.

CLINICAL PRESENTATION

Two patients who had tested positive for human immunodeficiency virus presented with progressive focal neurological deficits. Radiographic studies revealed solitary contrast-enhancing lesions in the right basal ganglia and right cerebellar hemisphere, respectively.

INTERVENTION

The first patient underwent a stereotactic biopsy but died despite appropriate therapy. The second patient died without tissue having been obtained for diagnosis. Postmortem examinations revealed necrotizing lesions with diffuse areas of infiltrating histiocytes containing eosinophilic cytomegalovirus inclusion bodies.

CONCLUSION

Although rare, cytomegalovirus infection should be considered in patients who have tested positive for human immunodeficiency virus and who present with enhancing intracranial lesions.

Effect of foscarnet on quantities of cytomegalovirus and human immunodeficiency virus in blood of persons with AIDS

Four intravenous dosages of foscarnet given for 10 days were compared with no therapy in persons with AIDS who had asymptomatic cytomegalovirus (CMV) viremia. CMV viremia was quantitated by endpoint cell dilution microcultures, pp65 antigenemia assay, and measurement of CMV DNA in peripheral blood leukocytes by a quantitative-competitive PCR. Human immunodeficiency virus type 1 (HIV-1) viremia was quantitated by endpoint cell dilution microculture, serum p24 antigen assay, and PCR for HIV-1 RNA in plasma. Twenty-seven subjects who had received a median of 22 months of nucleoside antiretroviral therapy were enrolled. Twenty-two subjects received foscarnet, which was well tolerated and decreased the CMV burden, as reflected by all three indicator assays. During the 10 days of dosing, the level of CMV viremia, as measured by 50 percent tissue culture infective doses, decreased from 117.5 to 12.7 (P = 0.001), the amount of CMV DNA decreased from 20,328 copies to 622 copies per 150,000 leukocytes (P = 0.02), and the level of CMV pp65 antigenemia decreased from 14.9 to 1.6 positive peripheral blood mononuclear cells per 50,000 leukocytes (P = 0.008). A significant pharmacodynamic relationship was found between the peak foscarnet concentration and a decrease in the level of CMV antigenemia (P < 0.05). Foscarnet had no effect on quantitative HIV-1 microcultures during the 10 days of treatment, but the HIV-1 p24 antigen level in serum decreased significantly, from 454 to 305 pg/ml (P = 0.01). Also, a significant pharmacodynamic relationship was seen between plasma HIV-1 RNA concentrations and both peak foscarnet concentration (P < 0.01) and the area under the foscarnet time-concentration curve (P < 0.05). Reductions in the levels of CMV and HIV-1 viremia correlated quantitatively with systemic exposure to foscarnet, whereas control subjects actually experienced an increase in CMV and HIV-1 burdens. The dual antiviral activity of foscarnet shown in this trial encourages investigation of its use in combination with other antiretroviral therapies for persons with AIDS.

Evaluation of the Digene Hybrid Capture System for detection and quantitation of human cytomegalovirus viremia in human immunodeficiency virus-infected patients

The Digene Hybrid Capture System (DHCS) is a solution hybridization antibody capture assay for the chemiluminescent detection and quantitation of cytomegalovirus (CMV) DNA in leukocytes. This assay was compared with the CMV antigenemia assay and shell vial and tube cultures for the detection of CMV in 234 blood specimens from 72 patients with human immunodeficiency virus. Intra- and interrun precision of the DHCS assay gave coefficients of variation of 17.8 and 16.3%, respectively. The correlation coefficient for the quantitative results obtained by the DHCS assay and the antigenemia assay was 0.911 (95% confidence interval, 0.885 to 0.930). Agreement between the DHCS assay and the other three assays ranged from 83 to 86%. The DHCS assay detected 71, 87, and 84% of specimens that were positive by antigenemia, shell vial cultures, and tube culture, respectively. A total of 92% of specimens that were positive by the DHCS assay were also positive by at least one of the other assays. Evaluation of the usefulness of quantitation of CMV DNA by using the DHCS assay and its correlation with clinical disease demonstrated that, with some exceptions, patients with clinical CMV disease tended to have high levels of DNA whereas asymptomatic patients tended to have low or undetectable levels. Overall, the DHCS assay provided a rapid, quantitative, and objective measure of CMV activity in leukocytes, but results did not always correlate with clinical disease.

Ophthalmic complications of HIV infection

HIV retinopathy, a noninfectious microangiopathy, is the most common ocular manifestation of HIV infection. Opportunistic infections, neoplasms, neuro-ophthalmic lesions, and drug-induced lesions may also cause ocular problems. Opportunistic ocular infections, particularly CMV retinitis, are a major cause of morbidity in patients with AIDS. Because of the underlying chronic and progressive immune dysfunction, the ocular symptoms, signs, clinical course, and treatment are often atypical and severe, requiring protracted medical therapy.

Role of Borrelia burgdorferi in the pathogenesis of morphea/scleroderma and lichen sclerosus et atrophicus: a PCR study of thirty-five cases

Morphea (localized scleroderma), and lichen sclerosus et atrophicus (LSA) share common features with acrodermatitis chronica atrophicans (ACA), a known chronic form of borreliosis. These include similar histologic findings such as diffuse dermal fibrosis. These observations have led several investigators to consider the possibility of Borrelia burgdorferi (Bb) as a common etiologic factor among all of these diseases. The aim of this study is to investigate the role of Bb in the pathogenesis of morphea and LSA, by assaying for its presence in lesional skin biopsies from patients with these diseases. We utilized the nested polymerase chain reaction (PCR) technique to selectively amplify a longer segment of a Bb-specific somatic gene, on DNA from paraffin-embedded, formalin-fixed tissues. The results revealed no Bb-specific DNA sequence in 28 specimens of morphea/scleroderma and 7 of LSA with varying stages of disease. Furthermore, confirmatory Southern blot of the PCR product, resulted in similar findings. These data seriously question the role played by this spirochete in the pathogenesis of morphea and LSA, at least in the southeastern part of the USA.

Titration of human cytomegalovirus (HCMV) DNA in urine by combined use of PCR and microplate hybridization in a renal transplant patient with HCMV pneumonitis

We titrated human cytomegalovirus (HCMV) DNA in urine specimens obtained from 14 healthy individuals and a renal transplant patient with HCMV pneumonitis by modifying the method for titration of varicella-zoster virus DNA previously described (1,2). Of 14 HCMV seropositive healthy individuals, 13 had HCMV DNA under the detection limit of 10(2.0) copies/ml, whereas one person had 10(2.0) copies/ml. The viral DNA in urine samples was at a low level in healthy individuals with latent infection. In a case with HCMV pneumonitis after renal transplantation, the amount of HCMV DNA in urine gradually increased from the level under 10(2.0) copies/ml and reached a peak of 10(4.7) copies/ml one month prior to the manifestation of pneumonitis. It, thereafter, decreased with the course of clinical remission, and finally settled at under 10(2.0) copies/ml. Serial titrations of HCMV DNA in urine specimens proved to be useful in identifying recipients at risk of developing active HCMV infection after renal transplantation and as a guide for treatment of patients.

Significance of human cytomegalovirus DNA detection in immunocompromised heart transplant patients

Peripheral blood samples (n= 1240), obtained at variable intervals from 483 heart transplantation (HTx patients under immunosuppressive therapy, and blood samples (n=1013) obtained upon blood donation from 1013 healthy anti-human cytomegalovirus (HCMV) positive blood donors, were tested for HCMV DNA by nested polymerase chain reaction (PCR). The detection limit of the nested PCR was determined to be less than 10 copies of the plasmid pRR 47, containing the HCMV immediate early gene. HCMV DNA was detected in 79 of 483 HTx patient (17%). To the contrary' HCMV DNA was only detected in 1 of 1013 anti-HCMV positive, healthy blood donors (0.1%). This PCR positive donor had recently contracted a primary HCMV infection. The rate of HCMV PCR positive immunosuppressed HTx patients in our study was lower than the rate of HCMV PCR positive healthy blood donors in previous reports in the literature. Blood samples (269 from 117 HTx patients) were assayed for HCMV DNA in peripheral blood leukocytes, HCMV DNA in plasma, and HCMV tegument protein 65 kDa (pp 65 antigen). Three laboratory diagnostic patterns were observed and related to clinical findings: (1) HCMV DNA only in leukocytes was observed in 26 patients, 7 of whom had HCMV disease, 5 of whom had graft rejection, and 14 of whom had no specific symptoms; (2) HCMV DNA both in leukocytes and in plasma (viremia) was observed in 3 patients, who were all symptomatic with HCMV disease; (3) HCMV DNA in leukocytes and in plasma (viremia) and pp 65 antigen were observed in 13 patients, all of whom were symptomatic (10 patients had HCMV disease, and 3 patients had graft rejection). A similar sequence of diagnostic patterns was observed in all symptomatic HCMV infections and reactivations in this study: HCMV DNA appeared first in peripheral blood leukocytes, then also in plasma, followed by pp 65 antigen detectable in peripheral blood leukocytes. Upon clinical recovery, these findings disappeared in reverse order. However, HCMV DNA remained detectable in peripheral blood leukocytes for several weeks. The detection of HCMV DNA in the peripheral blood is an exception, not the rule, even in severely immunosuppressed HTx patients. It indicates a pathological condition, albeit without clinical symptoms in some patients, and it is the earliest signal of HCMV replication. Of 42 patients in whom HCMV DNA was initially detected only in peripheral blood leukocytes, 16 patients progressed into viremia. Thus, HCMV-specific PCR performed on nucleic acid extracts from lysed peripheral blood is an appropriate method for the monitoring of HCMV infections in immunosuppressed HTx patients.

In situ detection of human cytomegalovirus DNA in gastrointestinal biopsies from AIDS patients by means of various PCR-derived methods

The development of new in situ assessment of HCMV disease on endoscopical gastrointestinal biopsies from AIDS patients is described and compared with the viral load measured by semiquantitative solution-phase PCR (SQ-PCR). Ten biopsies were examined by viral isolation, standard histology, in situ hybridization (ISH), in situ PCR-hybridization (PCR-ISH) and SQ-PCR, using the same target sequence. The methods developed for in situ HCMV detection were HCMV primers, the plasmid pCMV 406-S, a vector-free-digoxigenin-labelled HCMV-362 probe and the pSK + MCS nonsense probe. Paraffin-embedded MRC5 cells, either HCMV-infected or uninfected served as controls of specificity for ISH. beta-Actin primers were designed as markers of DNA integrity. Computerized models of the PCR, solution-phase and in situ PCR on formalin-fixed DNA indicated that HCMV and beta-actin primers were efficient and specific. Nine biopsies were negative for HCMV by histology and virus isolation. SQ-PCR revealed 80,000; 80 and < 80 HCMV genomic equivalents in 6, 2 and 2 biopsies, respectively. In 8 biopsies, both ISH and PCR-ISH identified positive nuclei in the intestinal epithelium, with sparing of the lamina propria. This indicates that an improvement in in situ methods can help the timely diagnosis of HCMV infection. Direct in situ PCR with beta-actin primers showed a positive signal in all the nuclei in the tissue sections, whereas omission of Taq polymerase resulted in an absence of signal, implying optimal in situ PCR. The data suggest an early-stage reactivation of HCMV, possibly harboured in the intestinal epithelium.

A sensitive and specific polymerase chain reaction-based assay for the diagnosis of cytomegalovirus retinitis

PURPOSE

To develop a sensitive and specific laboratory assay for the diagnosis of cytomegalovirus retinitis.

METHOD

We used a polymerase chain reaction-based assay for detection of cytomegalovirus DNA in vitreous samples. We attempted to detect cytomegalovirus DNA in 19 vitreous samples from patients with the acquired immunodeficiency syndrome (AIDS) who had untreated cytomegalovirus retinitis and in 40 vitreous samples from patients with AIDS who had been treated with systemic ganciclovir or foscarnet, or both. We also attempted to detect cytomegalovirus DNA in vitreous samples from 54 immunocompetent patients, including 32 with retinal detachment or macular hole, 11 with vitreous inflammation, and 11 with vitreous hemorrhage. Additionally, we attempted to detect cytomegalovirus DNA in 15 vitreous samples from patients with AIDS who had vitreoretinal inflammation not caused by cytomegalovirus.

RESULTS

Cytomegalovirus DNA was detected in 18 of 19 eyes with untreated cytomegalovirus retinitis. We detected cytomegalovirus DNA in 19 of 40 vitreous samples from patients with previously treated cytomegalovirus retinitis. Cytomegalovirus DNA was not detected in any of 69 patients who did not have a clinical diagnosis of cytomegalovirus retinitis. Thus, the assay had an estimated sensitivity of 95% in detecting untreated cytomegalovirus retinitis and a sensitivity of 48% in detecting cytomegalovirus retinitis that had been treated with systemic ganciclovir or foscarnet, or both. The assay did not give false-positive results in patients with vitreous hemorrhage or vitreous inflammation. Most important, the assay did not give false-positive results in AIDS patients with vitreous inflammation from causes other than cytomegalovirus retinitis.

CONCLUSION

We have developed a sensitive and specific diagnostic assay that will assist in the diagnosis of cytomegalovirus retinitis.

Continuous detection of CMV DNA in plasma of patients with advanced HIV infection implies the poorest prognosis

BACKGROUND

The contribution of cytomegalovirus (CMV) to progressive HIV infection is still controversial.

OBJECTIVE

The occurrence of CMV DNA in the plasma of patients with advanced HIV infection was studied in relation to the development of clinical disease.

STUDY DESIGN

Plasma samples were collected every 2 weeks for 6 months. The patients have thereafter been followed clinically at least every 3 months. CMV DNA was extracted and analysed by a nested PCR.

RESULTS

CMV DNA was repeatedly detected in the plasma of five patients for more than 45 days (group 1). These patients also had very low CD4+ cell counts 51+/-41 x 10(6) /l). Three patients in group 1 developed CMV complications and CMV was the cause of death in two cases. Two patients with anti-CMV IgM responses did not develop CMV complications. All five patients died at a mean of 17 months after CMV DNA became continuously detectable by PCR. In another six patients, CMV DNA was not or only sporadically detected (group 2). In these six patients, four are still alive after more than 3.5 years and only one patient developed CMV retinitis 3 years later.

CONCLUSIONS

The presence of CMV DNA in plasma was frequent in 11 patients with advanced HIV infection. The continued presence of CMV DNA in plasma of the patients with low CD4+ cell counts was related to the development of clinical CMV disease and carried the poorest prognosis.

Transfusion-transmitted cytomegalovirus: the part-time pathogen

Viral infection is a well-known risk of blood product transfusion and much work has been devoted to the detection of such well-known pathogens as human immunodeficiency virus and hepatitis viruses in blood donors. Cytomegalovirus (CMV) is found in a much larger percentage of donor units than these other viruses but will cause disease in only a minority of recipients. Many pediatric patients (especially premature infants) are at risk for transfusion-transmitted CMV. This review describes work delineating the populations of patients most at risk for transfusion-transmitted CMV, describes methods for detecting CMV in blood donors, evaluates current methods for leuko-depletion of blood products, and provides recommendations for patients most likely to benefit from blood products with low risk of CMV transmission.

[Current status of human cytomegalovirus disease]

Human cytomegalovirus (HCMV) can establish lifelong persistence after primary infection with reactivation occurring as a result of immunosuppression. There is much evidence that molecular interactions between the immune system and the HCMV are responsible for immune escape. HCMV in many cells especially in mononuclear blood cells during latency are frequently the source of transmission and spreading and results in a variety of disorders. In this review some data about acute infection in immunocompetent host (mononucleosis, hepatitis), about intrauterine HCMV infection, about infection and endogenous reinfection in bone marrow and solid organ transplant recipients (pneumonitis) and about HCMV disease in AIDS patients (encephalitis, neuropathy, retinitis, colitis) are investigated. Moreover, HCMV associated vasculitis is described in patients with myocarditis, rheumatoid arthritis or polyradiculopathy. HCMV could play an important role in atherosclerosis. Several types of human malignancy have been linked to HCMV and it has been shown that HCMV ie genes upregulate expression of cellular oncogenes. The diagnosis of HCMV infection is carried out by viremia in cell culture using immediate early antigen staining, by antigenaemia which appears to be an early quantitative and predictive tool, by HCMV DNA detection using hybridization and PCR, and by IgM and IgG antibody evaluation. Two antiviral drugs are used for treatment: ganciclovir and phosphonoformic acid; few resistant clinical isolates have been reported. Specific gammaglobulin activity is discussed. HCMV vaccine is not available.

Comparison of three methods for extraction of viral nucleic acids from blood cultures

Reliable nucleic acid extraction techniques for blood specimens are required for the sensitive detection of viral DNA. Standardized procedures for processing blood specimens for the molecular detection of herpesviruses (cytomegalovirus [CMV], herpes simplex virus, varicella-zoster virus, and Epstein-Barr virus [EBV]) have not been established. Three methods were used to extract DNA from blood specimens from healthy donors and asymptomatic immunocompromised patients: (i) IsoQuick treatment of whole blood, (ii) extraction of the peripheral blood leukocytes by lysis (lysis buffer and proteinase K), and (iii) extraction of peripheral blood leukocytes with phenol-chloroform (sodium docecyl sulfate solution and proteinase K). All blood specimens from 25 healthy blood donors were negative for CMV, herpes simplex virus and varicella-zoster virus nucleic acid sequences, regardless of the extraction method, while three samples (12%) extracted by the lysis technique were positive for EBV DNA. Of 25 blood samples from asymptomatic immunocompromised patients, CMV and EBV each were detected in nine specimens by lysis extraction, four each by IsoQuick and four (CMV) and six (EBV) by the phenol-chloroform method. Our results indicate that the lysis method is optimal for the detection of CMV and EBV DNA sequences by PCR from the leukocytic fraction of blood specimens. DNA of these viruses is frequently present in blood specimens from asymptomatic immunocompromised patients and occasionally from healthy donors.

Polymerase chain reaction detection of human cytomegalovirus in over 2000 blood specimens correlated with virus isolation and related to urinary virus excretion

The polymerase chain reaction (PCR) as applied to human cytomegalovirus (HCMV) detection should provide a valuable tool for rapid, reliable diagnosis of infection, thereby allowing prompt treatment. However, to date the high sensitivity of this technique and the lack of semi-quantitative interpretation have hindered establishing its validity for diagnosing systemic infection. We describe a rapid, simple, semi-quantitative PCR technique for HCMV detection. The validity of the technique was tested objectively by analyzing over 2000 leukocytes specimens by PCR and comparing the results with virus isolation from urine and blood in concomitant samples in the absence of any clinical data. It could thus be established that this technique had a sensitivity and specificity of 97%. When the PCR signal corresponded to > or = 8000 genome equivalents for 10(4) leukocytes, the predictive value for viremia was 86%. This semi-quantitative PCR technique should allow rapid diagnosis of systemic infection and provide a reliable means of monitoring clearance of CMV from blood during drug therapy.