Rapid detection of cytomegalovirus DNA in cerebrospinal fluid of AIDS patients with neurologic disorders

Ganciclovir and foscarnet dual-therapy for cytomegalovirus encephalitis: A case report and review of the literature

Cytomegalovirus (CMV) is a ubiquitous herpesvirus which establishes lifelong latency following primary infection. It is then capable of reactivating in the face of immunosuppression. Encephalitis is a less common, but particularly devastating syndrome associated with CMV. Here, we describe a case of CMV encephalitis in an allogeneic hematopoietic stem cell transplant recipient who received dual antiviral therapy with ganciclovir and foscarnet. The case presentation is followed by a summary of cases reported in the last ten years, with the goal of describing vulnerable patient populations, treatment courses, and outcomes. Finally, the discussion includes a review of the literature, with a focus on diagnostic criteria and the role for dual antiviral therapy in CMV encephalitis.

Clinical utility of viral load in management of cytomegalovirus infection after solid organ transplantation

The negative impact of cytomegalovirus (CMV) infection on transplant outcomes warrants efforts toward improving its prevention, diagnosis, and treatment. During the last 2 decades, significant breakthroughs in diagnostic virology have facilitated remarkable improvements in CMV disease management. During this period, CMV nucleic acid amplification testing (NAT) evolved to become one of the most commonly performed tests in clinical virology laboratories. NAT provides a means for rapid and sensitive diagnosis of CMV infection in transplant recipients. Viral quantification also introduced several principles of CMV disease management. Specifically, viral load has been utilized (i) for prognostication of CMV disease, (ii) to guide preemptive therapy, (iii) to assess the efficacy of antiviral treatment, (iv) to guide the duration of treatment, and (v) to indicate the risk of clinical relapse or antiviral drug resistance. However, there remain important limitations that require further optimization, including the interassay variability in viral load reporting, which has limited the generation of standardized viral load thresholds for various clinical indications. The recent introduction of an international reference standard should advance the major goal of uniform viral load reporting and interpretation. However, it has also become apparent that other aspects of NAT should be standardized, including sample selection, nucleic acid extraction, amplification, detection, and calibration, among others. This review article synthesizes the vast amount of information on CMV NAT and provides a timely review of the clinical utility of viral load testing in the management of CMV in solid organ transplant recipients. Current limitations are highlighted, and avenues for further research are suggested to optimize the clinical application of NAT in the management of CMV after transplantation.

Neurologic cytomegalovirus complications in patients with AIDS: retrospective review of 13 cases and review of the literature

Neurological disorders caused by Cytomegalovirus (CMV) in patients with Acquired Immunodeficiency Syndrome (AIDS) are rarely reported in the Highly Active Antiretroviral Therapy (HAART) period. The objective of this study was to describe the main clinical and laboratory features of patients with CMV-related neurological complications in HIV-infected patients admitted to a referral center in São Paulo, Brazil. CMV disease requires the identification of the virus in the cerebrospinal fluid (CSF) using Polymerase Chain Reaction (PCR). Thirteen cases were identified between January, 2004 and December, 2008. The median age of patients was 38 years and nine (69%) were men. At admission all patients were aware of their HIV status and only four (31%) patients were on HAART. Patients who were not on antiretroviral therapy before admission received HAART while inpatients. CMV disease was the first AIDS-defining illness in eight (62%) patients. The neurologic syndromes identified were diffuse encephalitis (n = 7; 62%), polyradiculopathy (n = 7; 54%), focal encephalitis (rhombencephalitis) (n = 1; 8%), and ventriculo-encephalitis (n = 1; 8%). Seven (54%) patients presented extra-neural CMV disease and four (31%) had retinitis. The median of CD4+ T-cell count was 13 cells/µL (range: 1-124 cells/µL). Overall in-hospital mortality was 38%. Eight patients used ganciclovir or foscarnet (in-hospital mortality: 50%) and five patients used ganciclovir and foscarnet (in-hospital mortality: 20%). None of the patients fulfilled the diagnosis criteria of immune reconstitution inflammatory syndrome. Four patients were lost to follow-up, and three patients presented immune recovery and discontinued secondary prophylaxis. Although infrequent, distinct neurological syndromes caused by CMV continue to cause high mortality among AIDS patients. Survival depends upon the use of effective antiviral therapy against CMV and the early introduction of HAART.

Single tube multiplex real-time PCR for the rapid detection of herpesvirus infections of the central nervous system

Human herpesvirus infection of immunocompromised hosts may lead to central nervous system (CNS) infection and diseases. In this study, a single tube multiplex real-time PCR was developed for the detection of five herpesviruses (HSV-1, HSV-2, VZV, EBV and CMV) in clinical cerebrospinal fluid (CSF) specimens. Two primer pairs specific for the herpesvirus polymerase gene and five hybridization probe pairs for the specific identification of the herpesvirus types were used in a LightCycler multiplex real-time PCR. A singleplex real-time PCR was first optimized and then applied to the multiplex real-time PCR. The singleplex and multiplex real-time PCRs showed no cross-reactivity. The sensitivity of the singleplex real-time PCR was 1 copy per reaction for each herpesvirus, while that of the multiplex real-time PCR was 1 copy per reaction for HSV-1 and VZV and 10 copies per reaction for HSV-2, EBV and CMV. Intra and inter-assay variations of the single tube multiplex assay were in the range of 0.02%-3.67% and 0.79%-4.35%, respectively. The assay was evaluated by testing 62 clinical CSF samples and was found to have equivalent sensitivity, specificity and agreement as the routine real-time PCR, but reducing time, cost and amount of used sample.

Human retinal and brain cell lines: A model of HCMV retinitis and encephalitis

Although HIV is accepted as the etiologic agent in AIDS, other factors have been implicated in accelerating the disease. Human cytomegalovirus (HCMV) in particular has been implicated as a cofactor in the progression from AIDS-related complex (ARC) to AIDS. HCMV infection of the central nervous system (CNS) (brain, retina) has been reported in at least 50% of AIDS patients, and has been implicated in producing encephalitis and sight-threatening retinitis. HCMV exhibits strict species specificity and animal models for human HCMV are conspicuous by their absence. We have developed a human brain cell line (mixed glial/neuronal) and a multipotential human retinal precursor cell line (neuronal in nature). We have tested the suitability of these cell lines as models for the study of HCMV infectibility. In this study, we report that these cell lines are optimal for the study of HCMV infectibility and pathogenesis in tissues of neural origin and appropriate to study HIV-HCMV interaction. Immortalized human brain and retinal cell lines were infected with a laboratory strain of HCMV (AD 169, Towne) at a multiplicity of infection moi (1-5) and viral infectibility and cell specificity monitored by: (a) phenotypic analysis (multinucleate cells, syncytium formation, etc.), (b) antigen expression (IE, E, late) by immunohistochemistry, Western blot analysis, (c) presence of viral particles by TEM, and (d) expression of indicator plasmids (HIV-LTR-CAT). We report that both human retinal and brain cell lines are permissive for HCMV infectibility. Cell specificity was not seen; both cells expressing glial/neuronal cell markers were positive for the presence of HCMV early/late antigens. Formation of multinucleate giant cells with nuclear inclusion bodies and syncytia were seen. Productive viral infection was confirmed by the ability of cell-free supernatant from the third passage of infected cells to produce pathogenicity and express viral particles, when added to fresh cultures. Using indicator plasmids, HIV-LTR, and CAT, we have shown that HIV and HCMV interact at the cellular level. We have also shown that HIV production in retinal and brain cell lines transfected with cloned HIV was enhanced by HCMV-IE genes. We did not see any differences in HCMV. AD 169, Towne isolate, and data from both strains is presented in this paper. This model could prove extremely useful for the study of cell specificity/cellular and molecular interaction between HIV/HCMV and to test antiviral therapies.

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.

HIV-associated neuropathic pain: epidemiology, pathophysiology and management

Peripheral neuropathy is associated with numerous systemic illnesses including HIV infection. Neuropathic pain constitutes approximately 25-50% of all pain clinic visits. Distal symmetrical polyneuropathy (DSP) is the most common form of peripheral neuropathy in individuals with HIV infection. DSP is distinguished from other forms of neuropathy on the basis of history and neurological examination. The pain associated with DSP can be debilitating. Therefore, it is important to diagnose HIV-associated DSP properly and treat the neuropathic pain in order to improve quality of life. We review the clinical manifestations, epidemiology, pathophysiology and management strategies for HIV-associated DSP.

Necrotising retinopathies simulating acute retinal necrosis syndrome

AIM

To determine an aetiological diagnosis in patients presenting with necrotising retinopathies that simulate acute retinal necrosis (ARN).

METHODS

Retrospective non-comparative case series. The charts of 16 patients presenting with a clinical impression of ARN at Pitie-Salpetriere Hospital, Paris, France, between 1994 and 1999, who required initial antiviral therapy were reviewed. All of the patients had extensive laboratory tests. Anterior chamber paracentesis was performed on 14 patients and evaluated by polymerase chain reaction (PCR) and/or the Witmer-Goldmann coefficient to determine the cause of retinitis. Three of the 14 cases also had diagnostic vitrectomy. Responses to specific treatment, initiated based on laboratory results, and the final outcome were evaluated.

RESULTS

Seven of the 16 patients were female and nine were male. The retinitis was bilateral in five patients and unilateral in 11 patients. The average age of the patients at presentation was 53.6 years. 13 patients were immune deficient for various reasons. Upon initial presentation, the patients' visual acuities were less than 20/200 in 68% of the affected eyes. The final diagnoses, based on laboratory data and therapeutic response were toxoplasmic retinochoroiditis (62.5%), syphilitic retinitis (12.5%), aspergillus endophthalmitis (12.5%), Behcet's disease (6.2%), and intraocular lymphoma (6.2%). Visual acuity was stabilised or improved in 12 patients (75%). Two patients with aspergillosis died despite antifungal therapy.

CONCLUSIONS

Toxoplasmic retinochoroiditis is the major cause of retinal necrosis that simulates ARN, and PCR analysis of the aqueous humour is helpful in establishing the diagnosis. Such atypical toxoplasma retinochoroiditis may be associated with poor visual outcome.

Quantitation of cytomegalovirus DNA in cerebrospinal fluid and serum specimens from AIDS patients using a novel highly sensitive nested competitive PCR and the cobas amplicor CMV monitor

A novel nested quantitative-competitive polymerase chain reaction (nQC-PCR) assay was developed to quantify as few as ten copies per tube of human cytomegalovirus DNA with an overall dynamic range of 10-10(5) copies per tube. This nQC-PCR assay is based on co-amplification of a mimic DNA and it was evaluated with 26 cerebrospinal fluid (CSF) specimens and 44 serum specimens from 70 CMV-infected AIDS patients, 35 of them were diagnosed of CMV retinitis. An excellent correlation was found between nQC-PCR assay and the commercially available Cobas Amplicor CMV Monitor trade mark (CACM) assay (R = 0.9999; P < 0.001; n = 42). Moreover, 13 serum samples with CMV viral loads undetectable with the CACM were successfully quantified by nQC-PCR. CMV viral load was significantly higher in patients with CMV retinitis (P = 0.003). The nQC-PCR assay described below is a very sensitive test for accurate quantitative detection of CMV DNA in different clinical specimens that avoids the need for high-cost instrumentation.

Human cytomegalovirus and Epstein-Barr virus type 1 in periodontal abscesses

OBJECTIVES

Recent studies have linked herpesviruses to severe types of periodontal disease, but no information exists on their relationship to periodontal abscesses. The present study determined the presence of human cytomegalovirus (HCMV) and Epstein-Barr virus type 1 (EBV-1) in periodontal abscesses and the effect of treatment on the subgingival occurrence of these viruses.

MATERIAL AND METHODS

Eighteen adults with periodontal abscesses participated in the study. Subgingival samples were collected from each patient with sterile curettes from an abscess-affected site and a healthy control site. HCMV and EBV-1 were identified by polymerase chain reaction at the time of the abscess and at 4 months after surgical and systemic doxycycline therapy.

RESULTS

HCMV was detected in 66.7% of periodontal abscess sites and in 5.6% of healthy sites (P=0.002). EBV-1 occurred in 72.2% of abscess sites but not in any healthy site (P<0.001). HCMV and EBV-1 co-infection was identified in 55.6% of the abscess sites. Posttreatment, HCMV and EBV-1 were not found in any study site.

CONCLUSIONS

HCMV and EBV-1 genomes are commonly found in periodontal abscesses. These data favor a model in which a herpesvirus infection of the periodontium impairs the host defense and serves as a platform for the entrance of bacterial pathogens into gingival tissue with subsequent risk of abscess development.

Prise en charge diagnostique et thérapeutique des rétinites nécrosantes herpétiques

PURPOSE

To study the viral cause and present the management of necrotizing herpetic retinopathies.

METHODS

Charts of patients presenting with acute retinal necrosis (ARN) or progressive outer retinal necrosis (PORN) diagnosed between March 1997 and June 2001 were retrospectively reviewed. Intraocular specimens were obtained in 33 cases to determine the viral cause using polymerase chain reaction-based assays and/or detection of intraocular antibody production.

RESULTS

The mean age was 43.4 Years. Herpesvirus genome was identified in 29 patients (80.5%). In the ARN group (32 patients, 38 eyes), herpes simplex virus (HSV) DNA was found in 11 patients (34.4%), varicella-zoster virus (VZV) in nine patients (28.1%), and cytomegalovirus (CMV) in four patients (12.5%). One patient (3.1%) presented an Epstein-Barr virus (EBV) infection. ARN was bilateral at initial examination in six patients and secondary bilateralization was observed in four patients. In the PORN group (four patients, eight eyes), the retinitis was bilateral and VZV DNA was detected in all cases. Two patients were treated with intravenous acyclovir, six with foscarnet alone, ten with intravenous foscarnet + acyclovir, 18 with intravenous foscarnet and intravitreous ganciclovir injections. Complications of necrotizing herpetic retinitis were cataract (26%), optic nerve atrophy (23.9%), and retinal detachment (17.4%). Final visual acuity was less or equal to 20/200 in 47.8% of cases.

CONCLUSIONS

It is important to determine the specific viral etiology since progression and prognosis may be different in herpetic necrotizing retinitis caused by HSV, VZV, or CMV. Visual prognosis is improved by intensive antiviral therapy, but remains poor if complications occur.

Prevalence of viral infection markers by polymerase chain reaction amplification and interferon-alpha measurements among patients undergoing lumbar puncture in an emergency department

Aseptic meningitis is a frequent diagnosis in emergency departments. Nevertheless, viral investigations are not carried out currently and the viral etiology in adult population has not been studied extensively. We conducted a prospective study including all consecutive patients undergoing lumbar puncture during a 15 months period in an adult emergency department. Bloody and purulent cerebrospinal fluid (CSF) were excluded. The main tests undertaken were: CSF genomic amplification by the polymerase chain reaction (PCR) for neurotropic viruses and serum and CSF interferon-alpha (IFN-alpha) measurements. Among 194 patients included, 45 had and 149 did not have aseptic meningitis. Of 45 patients with aseptic meningitis, 10 had alternative non-virological final diagnosis, and 35/45 were presumed to have neurological disorders of viral origin. Patients (27/35) completed virological analysis: 21/27 (78%) had either positive viral PCR (enterovirus: 8 patients, Varicella zoster virus (VZV): 5, Epstein-Barr virus (EBV): 2, herpes simplex virus (HSV): 1, human herpes virus 6: 1) or only raised serum or CSF IFN-alpha (4 patients). Overall, 59% of patients with a positive viral PCR had either CSF or serum raised IFN-alpha. Twentyone patients without meningitis had either positive viral PCR (enterovirus: 3 patients) or only high serum IFN-alpha level (18 patients). In the setting of aseptic meningitis diagnosed in an adult emergency department, viruses are the most common agents encountered, with enterovirus and VZV as the two main etiological agents. Current CSF viral genome amplification and IFN-alpha measurement are informative and could be useful to confirm the viral origin of various neurological disorders, although the sensitivity and specificity of IFN-alpha measurement for the diagnosis of viral infection need further confirmation.

Nonnecrotizing herpetic retinopathies masquerading as severe posterior uveitis

OBJECTIVE

Aqueous humor analysis can be performed in severe atypical forms of posterior uveitis unresponsive to conventional treatment to exclude a viral infection.

DESIGN

Noncomparative interventional case series.

PARTICIPANTS

Thirty-seven immunocompetent patients seen with corticosteroid-resistant forms of posterior uveitis underwent extensive evaluation, including anterior chamber paracentesis, to rule out a nonnecrotizing viral retinopathy.

INTERVENTION

Aqueous fluid samples were prospectively obtained. Polymerase chain reaction (PCR) and serologic evaluation of intraocular antibody production against herpesviruses were performed by molecular techniques and enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

Polymerase chain reaction and local antibody production for herpes simplex virus types 1 and 2, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus were determined on aqueous fluid samples.

RESULTS

Viral infection was confirmed in 5 cases (13.5%). Clinical presentation included birdshot-like retinochoroidopathy, occlusive bilateral vasculitis, and cystoid macular edema. An antiviral regimen was initiated in all cases. Inflammation was stabilized, and steroid dosage could be significantly reduced.

CONCLUSIONS

Identification of a viral agent during severe posterior uveitis can dramatically change therapeutic management.

Polymerase chain reaction analysis of aqueous humour samples in necrotising retinitis

AIM

To evaluate the diagnostic value of polymerase chain reaction (PCR) performed on aqueous humour for the detection of viral DNA in patients with necrotising herpetic retinitis.

METHODS

The clinical features and laboratory results of 22 patients (29 eyes) presenting with necrotising herpetic retinitis between March 1999 and June 2001 were reviewed retrospectively. Aqueous humour was obtained after anterior chamber paracentesis and PCR was performed in all cases.

RESULTS

Viral DNA was detected in the aqueous humour of 19 patients (86.4%). Epstein-Barr virus (EBV) seroconversion was evidenced in one additional patient. In the acute retinal necrosis (ARN) group (n = 19), varicella zoster virus (VZV) DNA was identified in six patients, herpes simplex virus 1 (HSV-1) DNA in two patients, herpes simplex virus 2 (HSV-2) DNA in four patients, and cytomegalovirus (CMV) genome in four patients. In the progressive outer retinal necrosis (PORN) group (n = 3), VZV DNA was detected in all patients. No sample was positive for more than one virus.

CONCLUSIONS

PCR analysis of aqueous humour in patients with clinical features of necrotising viral retinitis can provide specific aetiological orientation and the method appears to be safe and highly sensitive.

Molecular analysis of cerebrospinal fluid in viral diseases of the central nervous system

The use of nucleic acid (NA) amplification techniques has transformed the diagnosis of viral infections of the central nervous system (CNS). Because of their enhanced sensitivity, these methods enable detection of even low amounts of viral genomes in cerebrospinal fluid. Following more than 10 years of experience, the polymerase chain reaction or other NA-based amplification techniques are nowadays performed in most diagnostic laboratories and have become the test of choice for the diagnosis of several viral CNS infections, such as herpes encephalitis, enterovirus meningitis and other viral infections occurring in human immunodeficiency virus-infected persons. Furthermore, they have been useful to establish a viral etiology in neurological syndromes of dubious origin and to recognise unusual or poorly characterised CNS diseases. Quantitative methods have provided a valuable additional tool for clinical management of these diseases, whereas post-amplification techniques have enabled precise genome characterisation. Current efforts are aiming at further improvement of the diagnostic efficiency of molecular techniques, their speed and standardisation, and to reduce the costs. The most relevant NA amplification strategies and clinical applications of to date will be the object of this review.

CNS manifestations of cytomegalovirus infections: diagnosis and treatment

Cytomegalovirus (CMV) infection of the CNS occurs most commonly in patients with severe immunosuppression such as those with advanced HIV infection (i.e. AIDS) or those who have undergone bone marrow or solid organ transplantation. Immunocompetent patients are affected very rarely. The infection of the CNS may affect the brain (diffuse encephalitis, ventriculoencephalitis, cerebral mass lesions) or the spinal cord (transverse myelitis, polyradiculomyelitis). Diagnosis is very difficult and should be based on clinical presentation, results of imaging and virological markers. The most specific diagnostic tool is the detection of CMV DNA by polymerase chain reaction in the CSF. Treatment should be initiated promptly if CMV infection is suspected. Antiviral therapy consists of intravenous ganciclovir, intravenous foscarnet or a combination of both. Cidofovir is the treatment of second choice. Patients who experience clinical improvement or stabilisation during induction therapy should be given maintenance therapy. After immune reconstitution (in HIV-positive patients) or discontinuation of immunosuppressive therapy (in transplant recipients), maintenance therapy may be stopped. Despite therapy, the prognosis for long-term survival is very poor, especially in patients with AIDS.

Focal neurological disease in patients with acquired immunodeficiency syndrome

Focal neurological disease in patients with acquired immunodeficiency syndrome may be caused by various opportunistic pathogens and malignancies, including Toxoplasma gondii, progressive multifocal leukoencephalopathy (PML), cytomegalovirus (CMV), and Epstein-Barr virus-related primary central nervous system (CNS) lymphoma. Diagnosis may be difficult, because the findings of lumbar puncture, computed tomography (CT), and magnetic resonance imaging are relatively nonspecific. Newer techniques have led to improved diagnostic accuracy of these conditions. Polymerase chain reaction (PCR) of cerebrospinal fluid specimens is useful for diagnosis of PML, CNS lymphoma, and CMV encephalitis. Recent studies have indicated the diagnostic utility of new neuroimaging techniques, such as single-photon emission CT and positron emission tomography. The combination of PCR and neuroimaging techniques may obviate the need for brain biopsy in selected cases. However, stereotactic brain biopsy, which is associated with relatively low morbidity rates, remains the reference standard for diagnosis. Highly active antiretroviral therapy has improved the prognosis of several focal CNS processes, most notably toxoplasmosis, PML, and CMV encephalitis.

Congenital HCMV infection: a collaborative and comparative study of virus detection in amniotic fluid by culture and by PCR

Cytomegalovirus (HCMV) infection is the leading cause of congenital virus infection in developed countries, affecting an estimated 1% of births. This antenatal infection can cause serious sequelae. Strategies for prevention and treatment must, therefore, be agreed upon, entailing a preliminary performance assessment of antenatal virus diagnosis techniques. Between 1992 and 1999, HCMV serology status was established for 19456 pregnant women in four French hospitals. Seronegative patients (55.4%) were given serology screening, and antenatal diagnosis was given to 152 women who had shown seroconversion during their pregnancies (1.4%). The detection of HCMV transmission from mother to fetus was finally established in 95 cases, using polymerase chain reaction (PCR) and viral culture methods for detecting HCMV in the amniotic fluid. These results were compared with viral culture of children's urine after birth, enabling us to distinguish between children really infected in utero (30%) and non-infected children (70%). The results of the virus culture and those of PCR were identical in 94 of the 95 cases, with one discrepancy (culture-/PCR+). The two diagnosis techniques had identical sensitivity (72%), with culture proving slightly more specific than PCR (98.4% as opposed to 96.9%). Positive prediction values for culture and for PCR were, respectively, 95.6 and 91.3%. Antenatal virus diagnosis on amniotic fluid was negative with both techniques in 8 out of 29 cases of children born with HCMV infection (VPN=89%). Over half of these wrongly negative results can be explained by amniocentesis carried out too early in the pregnancy or too early with respect to the mother's primary infection.

Comparison of three nucleic acid amplification assays of cerebrospinal fluid for diagnosis of cytomegalovirus encephalitis

The diagnostic reliabilities of three cytomegalovirus (CMV) nucleic acid amplification assays of cerebrospinal fluid (CSF) were compared by using CSF samples from human immunodeficiency virus-infected patients with a postmortem histopathological diagnosis of CMV encephalitis (n = 15) or other central nervous system conditions (n = 16). By using a nested PCR assay, the quantitative COBAS AMPLICOR CMV MONITOR PCR, and the NucliSens CMV pp67 nucleic acid sequence-based amplification assay, sensitivities were 93.3, 86.6, and 93.3%, respectively, and specificities were 93.7, 93.7, and 87.5%, respectively. The COBAS AMPLICOR assay revealed significantly higher CMV DNA levels in patients with diffuse ventriculoencephalitis than in patients with focal periventricular lesions.

Detection of human cytomegalovirus pp67 late gene transcripts in cerebrospinal fluid of human immunodeficiency virus type 1-infected patients by nucleic acid sequence-based amplification

This study examined the clinical correlation between the presence of human cytomegalovirus (HCMV) pp67 mRNA in cerebrospinal fluid (CSF) and active HCMV central nervous system (CNS) disease in patients with human immunodeficiency virus type 1 (HIV-1). In total, 76 CSF specimens collected from 65 HIV-1-positive patients diagnosed with HCMV CNS disease, other non-HCMV-related CNS diseases, or no CNS disease were tested for the presence of HCMV pp67 mRNA using the NucliSens cytomegalovirus (CMV) pp67 assay (Organon Teknika, Durham, N.C.). The results were compared to those of a nested PCR for the detection of HCMV glycoprotein B DNA and to those obtained by viral culture (54 samples). CSF specimens collected from patients without HCMV CNS disease yielded the following results: pp67 assay negative, 62 of 62 specimens; culture negative, 41 of 41 specimens; and PCR negative, 56 of 62 specimens (6 specimens were positive). CSF specimens collected from patients with HCMV CNS disease yielded the following results: pp67 assay positive, 9 of 13 specimens; PCR positive, 13 of 13 specimens; and culture positive, 2 of 13 specimens. After resolution of the discordant results, the following positive and negative predictive values (PPV and NPV, respectively) for the diagnosis of HCMV CNS disease were determined. The PPV for PCR, pp67 assay, and culture were 68.4, 100, and 100%, respectively, and the NPV for PCR, pp67 assay, and culture were 100, 97.0, and 82. 7%, respectively. The sensitivities for DNA PCR, pp67 assay, and culture for the detection of HCMV were 100, 84.6, and 18%, respectively, and the clinical specificities were 90.5, 100, and 100%, respectively. This study indicates that the detection of HCMV pp67 mRNA in CSF has good correlation with active HCMV CNS disease, whereas CSF culture is insensitive and qualitative DNA PCR may detect latent nonreplicating virus in CSF from patients without HCMV CNS disease.

Asymmetric periflexural exanthem of childhood: microbiologic case-control study

Our objective was to study possible etiologic factors of asymmetric periflexural exanthem of childhood (APEC) among a large panel of microbiologic agents not yet investigated. To do so, we designed a prospective case-control study using throat, stool, blood, and skin samples, and enlisted 37 children with APEC and 37 age-matched controls without eruption seen consecutively from February 1995 to April 1996 from a mixed referral center and community-based population. No interventions were done. Used as the main outcome measure was the differences in the two groups for microbiologic investigations. No significant statistical differences between cases and controls for virus and bacteria investigated were found. No microorganism was identified as a possible etiologic agent in any of the APEC patients. APEC is not a nonspecific cutaneous eruptive pattern to several common microbiologic agents. More sophisticated molecular approaches are needed to address its etiology.

Induction and maintenance therapy of cytomegalovirus central nervous system infection in HIV-infected patients

OBJECTIVE

To evaluate the efficacy and safety of the foscarnet-ganciclovir combination in induction therapy (IT) and maintenance therapy (MT) for cytomegalovirus (CMV) central neurological disorders in HIV-infected patients.

DESIGN

An open pilot non-comparative multicentre study.

METHODS

Thirty-one patients with acute CMV encephalitis (CMVe) (n = 17) or CMV myelitis (CMVm) (n = 14) during the era before highly active antiretroviral therapy (HAART) received intravenous IT with foscarnet 90 mg/kg plus ganciclovir 5 mg/kg twice a day followed by MT. The primary endpoint was clinical efficacy, assessed at the end of the induction phase.

RESULTS

The foscarnet-ganciclovir combination in IT resulted in a 74% (23 out of 31 patients) clinical improvement or stabilization. Eight patients did not respond clinically. Side-effects leading to drug discontinuation occurred in 10 patients during IT. Among the 23 patients who qualified for the maintenance phase, CMV disease progressed in 10, with a median time to the first relapse of 126 days (range 64-264 days). Overall, the median survival time was 3 months [95% confidence interval (CI), 2-4 months].

CONCLUSION

The combination of foscarnet and ganciclovir can safely be used for CMV central nervous system (CNS) infection, with an improvement or stabilization in 74% of patients. Life-long MT with this combination is recommended as long as the immune system is profoundly impaired.

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.

Viral diagnosis of neurological infection by RT multiplex PCR: a search for entero- and herpesviruses in a prospective study

The diagnosis of a wide range of different neurological syndromes was established by a reverse transcription multiplex PCR assay. The presence of enterovirus and herpesviruses was studied in cerebrospinal fluid samples collected prospectively from 200 patients hospitalized with neurological diseases suspected of viral infection. Positive PCR results for enterovirus and neurotropic herpesvirus (herpes simplex, HSV, and varicella zoster, VZV) were obtained among the immunocompetent patients (55/156, 35%) who presented aseptic meningitis or encephalitis. Among immunocompromised patients the yield of positive PCR results was 41% (18/44), predominantly lymphotropic herpesviruses (15/44, 34%). Cytomegalovirus (CMV) DNA was detected in patients with several clinical syndromes, including encephalitis, chronic meningitis, retinitis, ventriculitis, polyradiculomyelitis, and myeloradiculitis. Epstein-Barr (EBV) and VZV-specific DNA sequences were detected in patients with either encephalitis, aseptic meningitis, and chronic meningitis. Dual infections of CMV and HSV or CMV and EBV were established in two AIDS patients with encephalitis and polyradiculomyelitis, respectively. The applications of this RT multiplex PCR assay are extensive and may prove to be particularly valuable for the rapid and sensitive diagnosis of neurological diseases in both immunocompetent and immunocompromised patients.

Two cases of cytomegalovirus infection revealed by hearing loss in HIV-infected patients

Neurological complications are particularly common during HIV infection. Among various opportunistic diseases, cytomegalovirus (CMV) is one of the most frequent causes of central and peripheral neurological manifestations. Previously, there have been several reports of cranial nerve infection by CMV, but to our knowledge, no cases of auditory nerve involvement have been described. We report two cases in which CMV infection was revealed by involvement of the VIIIth cranial nerves. Cytomegalovirus (CMV) infection is frequent in severely immunodeficient patients infected by human immunodeficiency virus (HIV). The main targets of CMV are the retina, gastrointestinal tract and central nervous system. We describe two cases in which neurologic CMV infection was revealed by hearing loss.

Human cytomegalovirus (HCMV) encephalitis in an immunocompetent young person and diagnostic reliability of HCMV DNA PCR using cerebrospinal fluid of nonimmunosuppressed patients

Human cytomegalovirus (HCMV) encephalitis in adult nonimmunosuppressed patients has rarely been reported. We have diagnosed HCMV encephalitis in an anti-HCMV immunoglobulin G-negative, nonimmunosuppressed young woman by HCMV DNA PCR and virus isolation from cerebrospinal fluid (CSF). At the same time, HCMV antigen and HCMV DNA could be demonstrated in peripheral blood leukocytes, and the virus was isolated in fibroblast cultures. After 22 days of acute illness, the virus disappeared from the CSF. Remarkably, the patient did not generate detectable anti-HCMV antibodies within 5 months after the beginning of illness. To investigate the significance of HCMV DNA detection in CSF, samples of CSF, blood cells, and serum from 35 nonimmunosuppressed patients with various neurological disorders (but no herpes simplex virus central nervous system [CNS] disease) were tested for HCMV DNA, antigen, and antibodies. Eleven of these patients were found to be positive for virus DNA and/or antigen in peripheral blood leukocytes. Additionally, HCMV DNA was detected in the CSF of two patients with noninflammatory CNS diseases. A causative role of HCMV in the CNS diseases of these two patients was not evident. In summary, HCMV DNA amplification from CSF samples is a very suitable method to verify HCMV-associated encephalitis, but it should be taken into consideration that there are few cases of positive PCR with DNA from CSF without any known clinical correlative.

Evaluation of a commercial PCR kit for diagnosis of cytomegalovirus infection of the central nervous system

We evaluated the AMPLICOR cytomegalovirus (CMV) PCR kit for the diagnosis of neurologic CMV infections on 43 positive and 112 negative archived cerebrospinal fluid specimens originally tested by an in-house PCR method. The AMPLICOR kit showed sensitivity and specificity of 95 and 100%, respectively, versus the home-grown assay, indicating its utility in this clinical setting.

Diagnostic imaging of the brain in acquired immunodeficiency syndrome (AIDS)

The central nervous system is commonly involved in acquired immunodeficiency syndrome (AIDS), resulting in a variety of lesions and diseases. They can be divided into the primary effects of human immunodeficiency virus (HIV), opportunistic infections, tumors, and vascular disease. This article is a review of the major imaging findings observed in each disease, with clinical and pathological correlations relevant to the goal of differential diagnosis.

Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis

BACKGROUND

Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology. Methodological standards for selection and evaluation of patient materials are essential to the provision of reliable diagnosis, yet few studies have addressed this important issue.

OBJECTIVES

To describe and define methodological standards and reference methodology for diagnosis of herpesvirus infections of the CNS.

STUDY DESIGN

Information gathered by literature review.

RESULTS

Only for herpes simplex encephalitis is there sufficient data to allow the definition of reference methodology. Good methodological standards exist but few studies have adhered to these standards. As methods for the detection of specific intrathecal antibody synthesis are well established yet under-used in diagnostic virology, the principle of these measurements is reviewed in some detail.

CONCLUSIONS

Herpesvirus infections of the CNS are of increasing importance. High quality, multi-centre studies are needed to establish the value of the new diagnostic test procedures if further improvement in the diagnostic sensitivity and specificity of these procedures is to be achieved.

Relevance of clinical and laboratory findings in the diagnosis of cytomegalovirus encephalitis in patients with AIDS

A retrospective evaluation was conducted in patients with AIDS and an autopsy diagnosis of cytomegalovirus (CMV) encephalitis to determine the relevance of clinical and laboratory findings in establishing a diagnosis. On autopsy of 100 patients, CMV encephalitis was diagnosed in 13 patients; eight had periventricular CMV encephalitis, four micronodular CMV encephalitis, and one both conditions. Seven patients had had a CMV infection previously (6 cases of retinitis, 1 case of colitis), and at the onset of encephalitis all of them were receiving a maintenance dose of ganciclovir. Examination of the CSF showed specific changes in patients with periventricular encephalitis. CT revealed no characteristic findings, while MRI showed an increased signal intensity on T2 weighted images. CMV DNA amplification by nested PCR was performed in nine patients with CMV encephalitis; PCR was positive in eight patients whose CSF was collected during CMV encephalitis, and negative in one patient whose CSF was collected six months before death. In conclusion, some clinical findings suggest a presumptive diagnosis, especially of periventricular encephalitis, and nested PCR appears to be a reliable and rapid technique for making an antemortem diagnosis.

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.

Predictors of cytomegalovirus disease, natural history and autopsy findings in a cohort of patients with AIDS

OBJECTIVE

To identify the predictors of acquiring cytomegalovirus (CMV) disease, and to describe natural history, therapeutic management and autopsy findings in affected patients.

DESIGN

Observational study of a consecutive cohort of AIDS patient diagnosed and followed in the same institution.

METHODS

All of the patients with CMV were included. Statistical analyses were performed to establish the risk of acquiring the disease at or after AIDS presentation, survival, and the occurrence and time of relapses in relation to maintenance therapy. The presence of CMV infection at autopsy was also investigated.

RESULTS

CMV disease was diagnosed in 304 (24.8%) out of 1,227 patients, its incidence increasing according to the year of AIDS diagnosis. Women, homosexual men, patients given zidovudine and Pneumocystis carinii pneumonia (PCP) prophylaxis before AIDS, and severely immunodepressed patients were at higher risk for the disease. CMV disease was an independent factor of worse survival (hazard ratio, 1.7 versus PCP; 95% confidence intervals, 1.28-2.13). Patients untreated during the acute phase had a 4.3 higher risk of dying than those treated. Relapses occurred less frequently and later in patients given continuous maintenance treatment (23 out of 113; 17 months) than in untreated patients (13 out of 16; 3 months) or those given discontinuous therapy (22 out of 40; 7 months), whereas survival was independent from treatment. CMV infection was found in 97 out of 134 patients at autopsy, but was unassociated with relapse.

CONCLUSIONS

CMV is a severe disease whose frequency is higher in severely immunodepressed patients. Continuous treatment leads to a lower relapse rate even if it does not change survival or eradicate the infection.

Acute lumbosacral polyradiculopathy due to cytomegalovirus in advanced HIV disease: CSF findings in 17 patients

OBJECTIVES

To describe the abnormalities in CSF from HIV infected patients with acute lumbosacral polyradiculopathy (ALP) caused by cytomegalovirus (CMV) infection.

METHODS

Retrospective case notes and laboratory records were reviewed for 17 consecutive patients with CMV associated ALP admitted to specialist HIV/AIDS units at UCL Hospitals and Chelsea and Westminster Hospital.

RESULTS

Infection with CMV was confirmed by detection of CMV DNA by polymerase chain reaction amplification in 15 patients (all of whom were negative by culture), by culture in one patient, and by objective clinical response to anti-CMV treatment in one patient. Only nine patients had a CSF pleocytosis 28-1142 (median 150) cells/mm3; in seven there was a polymorphonuclear (PMN) leucocyte preponderance. Protein concentrations in CSF were moderately or considerably raised in 13 patients; CSF: plasma glucose ratios were < or = 50% in five patients. Two patients had no pleocytosis, normal CSF: plasma glucose, and normal or near normal protein values.

CONCLUSIONS

Abnormalities in CSF in CMV associated ALP are varied: only 50% of patients have a "typical" PMN preponderant pleocytosis. The diagnosis of this condition should not rely on demonstration of a PMN preponderant pleocytosis, but on identification of CMV DNA in CSF and the exclusion of other opportunistic infections and lymphoma in order that specific anti-CMV treatment may be instituted.

Neurologic manifestations of HIV infection

A wide spectrum of central and peripheral nervous system abnormalities may be associated with HIV infection. These disorders may be caused by HIV infection, result as secondary complications related to immunosuppression, or be a neurotoxic effect of therapeutic agents. The range of neurologic disorders includes dementia, focal cerebral mass lesions, myelopathy, peripheral neuropathies, and myopathy. Early diagnosis and therapy is critical, and may result in substantial improvement in patients' quality and quantity of life. This article reviews the approach to differential diagnosis of these neurologic disorders and presents theories of pathogenesis and current approaches to treatment.

[Early diagnosis and treatment of cytomegalovirus polyradiculoneuritis in a child infected by HIV]

BACKGROUND

Axonal polyradiculopathy due to cytomegalovirus (CMV) in AIDS has been reported in adults but it is not well documented in children.

OBJECTIVE

We describe the elements of diagnosis and the outcome after anti-CMV therapy in a pediatric case.

CASE REPORT

A 11-year-old boy with post-transfusional AIDS and low CD4 count (< 50/mm3) suffered from bilateral leg pain and weakness progressing within 15 days to paraplegia and cauda equina syndrome. Electromyography showed pure axonal neuropathy. Examination of the CSF showed increased proteins, low glucose concentration, neutrophilic pleiocytosis and positive detection of CMV by polymerase-chain reaction. The CMV viremia was positive. Treatment with ganciclovir and foscarnet allowed dramatical clinical improvement. Retinitis occurred during the maintenance therapy and was cured after reintroduction of the initial doses of ganciclovir and foscarnet. The child died five months later from a bacterial pneumopathy.

CONCLUSIONS

Children with advanced AIDS may benefit from early recognition and treatment of CMV polyradiculopathy. The interactions and cumulated toxicities between anti-CMV and anti-retroviral drugs must be considered. The prognosis remains poor for CMV neuropathy due to the severe immunodepression caused by the HIV infection.

Significance of cytomegalovirus (CMV)-pp65 antigenemia in the diagnosis of CMV disease in human immunodeficiency virus-infected patients

To establish the diagnostic value of the cytomegalovirus (CMV)-pp65 antigenemia in CMV disease occurring in human immunodeficiency (HIV)-infected patients, CMV-pp65 antigen in polymorphonuclear leukocytes (PMNLs) was assayed in 373 samples from 138 randomly included patients followed up for symptomatic HIV-1 infection and the correlation between CMV-pp65 antigenemia and diagnosis of CMV disease was investigated. Thirty-seven CMV disease episodes were observed in 30 patients and 89.2% of these episodes were associated with a positive CMV-pp65 antigenemia. In contrast, 94% of the patients negative for CMV-pp65 antigenemia remained free of CMV disease. Patients with CMV disease had significantly higher levels of CMV-pp65 antigenemia than CMV disease-free patients (695 positive cells/2 x 10(5) PMNLs vs. 28 positive cells/2 x 10(5) PMNLs). The positive and negative predictive values of the test were 45% and 94%, respectively, but were 93% and 80%, respectively, when a CMV-pp65 antigenemia level of > 100 positive cells/2 x 10(5) PMNLs was taken into consideration. These results indicate that the CMV-pp65 antigenemia assay is useful for the diagnosis and monitoring of CMV disease in HIV-infected patients.

Structure-activity relationships among 2-substituted 5,6-dichloro-, 4,6-dichloro-, and 4,5-dichloro-1-[(2-hydroxyethoxy) methyl]- and -1-[(1,3-dihydroxy-2-propoxy) methyl]benzimidazoles

The sodium salt of 2,5,6-trichlorobenzimidazole (8a) was condensed with [2-(benzyloxy)ethoxy]-methyl chloride (9) and [1,3-bis(benzyloxy)-2-propoxy]methyl chloride (18) to provide the corresponding protected acyclic nucleosides 10a and 19a, which on debenzylation afforded 2,5,6-trichloro-1-[(2-hydroxyethoxy)methyl]benzimidazole (11a) and 2,5,6-trichloro-1-[(1,3-dihydroxy-2-propoxy)methyl] benzimidazole (20a), respectively. A similar condensation of 2,4,6-trichlorobenzimidazole (2a) and 2,4,5-trichlorobenzimidazole (7a) followed by debenzylation yielded 11b, 20b, 11c, and 20c, respectively. A nucleophilic displacement of the 2-chloro group of 11a-c and 20a-c with liquid ammonia, methylamine, dimethylamine, and thiourea furnished several interesting 2-substituted compounds in good yields, e.g., 12-14(a-e), 21-23(a-e), 15-17, and 24-26. Alkylation of the 2-thio analogs 15-17 and 24-26 with benzyl chloride furnished the 2-alkylthio acyclic nucleosides 12d-14d and 21d-23d. Desulfurization of 15 and 24 with Raney Ni furnished 5,6-dichloro-1[(2-hydroxyethoxy)methyl]benzimidazole (12e) and 5,6-dichloro-1-[1,3-dihydroxy-2-propoxy)methyl]benzimidazole (21e), respectively (acyclic analog of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole). Similarly the dihalo compounds 13e, 14e, and 23e were prepared in moderate yields from the 2-thio analogs 16,17, and 26. Treatment of 2-bromo-5,6-dichlorobenzimidazole (8b) with 27 and 30 gave the protected acyclic compounds 28a and 31a, which on deacetylation with sodium carbonate and potassium cyanide yielded 2-bromo-5,6-dichloro-1-[(2-hydroxyethoxy)methyl]benzimidazole (29a) and 2-bromo-5,6-dichloro-1-[(1,3-dihydroxy-2-propoxy)methyl]benzimidazole (32a), respectively, in moderate yields. The 2-bromo-4,6-dichlorobenzimidazole and 2-bromo-,5-dichlorbenzimidazole analogs 29b,c and 32b,c were prepared in a similar manner. Compounds were tested for activity against human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) and for cytotoxicity. In marked contrast to the ribosylbenzimidazoles, none of the acyclic analogs were specific and potent inhibitors of HCMV. Only the 2-thiobenzyl analogs 12d, 13d, 14d, and 23d and the 2-Br analogs 32a,b were active, but activity was not well separated from cytotoxicity. The lack of specific and potent antiviral activity strongly suggests that these acyclic nucleoside analogs are not phosphorylated by HCMV or HSV-1 gene products and that the ribosylbenzimidazoles do not require phosphorylation for antiviral activity.

New PCR assay for rapid and quantitative detection of human cytomegalovirus in cerebrospinal fluid

Rapid Chelex extraction combined with an automated hybridization assay for the detection of PCR-amplified human cytomegalovirus DNA from cerebrospinal fluid was established. Quantitation of DNA was performed with a plasmid being used as an external standard. The detection limit was 10 copies per microliter. Quantitative detection of human cytomegalovirus DNA could be achieved over a range from 10 to 10(4) copies per microliter.

Detection of human cytomegalovirus mutations associated with ganciclovir resistance in cerebrospinal fluid of AIDS patients with central nervous system disease

To examine the involvement of ganciclovir-resistant strains in the development of central nervous system (CNS) disease caused by human cytomegalovirus (HCMV), 14 AIDS patients with CNS disease caused by HCMV were studied for the presence of HCMV strains with UL97 gene mutations associated with ganciclovir resistance by using amplification and direct sequencing of HCMV DNA in cerebrospinal fluid (CSF). The CSF of all seven patients who had not received ganciclovir prior to the development of CNS disease and four patients who had been receiving the drug for 3 to 8 months contained wild-type UL97 sequences. The CSF of three patients who had received ganciclovir for 12 to 30 months contained HCMV strains with nucleotide changes leading to single-amino-acid substitutions within conserved UL97 sites implicated in nucleotide binding (position 460) and substrate recognition (position 591). Patients containing mutant and wild-type strains revealed a similar spectrum of clinical and histopathologic manifestations. These findings indicate that CNS disease in AIDS patients receiving prolonged ganciclovir therapy can be caused by ganciclovir-resistant HCMV strains. Direct genotypic analysis of HCMV DNA within CSF should help to identify ganciclovir-resistant virus and to guide anti-HCMV therapy.

Quantitation of human cytomegalovirus genomes in the brain of AIDS patients

Human cytomegalovirus (HCMV) is one of the major pathogens causing neurologic disease in the immunocompromised host. A competitive nested polymerase chain reaction (PCR) was used to determine DNA load, distribution, and sequence variability of HCMV genomes in the brain of AIDS patients with and without HCMV encephalitis confirmed by histology and immunocytochemistry. By quantitative PCR, HCMV genomes were found to be distributed diffusely in the central nervous system (CNS) of all five patients with histologically proven HCMV encephalitis, but also in the brain of five of eight AIDS patients without neuropathological evidence of HCMV encephalitis. The viral DNA load in cases with HCMV encephalitis was increased 10- to 1,000-fold as compared to patients without evidence of encephalitis. A viral load above 6,000 copies HCMV/10(6) copies beta-globin was found to be highly suggestive for HCMV encephalitis. Characterization of PCR products by temperature gradient gel electrophoresis (TGGE) and direct sequencing allowed us to detect a sequence variability of the amplified fragment of HCMV glycoprotein B (gB) among different patients, but also among different HCMV foci within the same patient. Furthermore, two of five AIDS patients with HCMV encephalitis most likely experienced double infections with different HCMV strains. The experimental procedure described in this study should also be applicable to the detection of significant HCMV DNA levels in biopsy samples.

Detection of cytomegalovirus DNA in cerebrospinal fluid in immunocompetent patients as a sign of active infection

Detection of cytomegalovirus (CMV) DNA by the polymerase chain reaction (PCR) in samples of cerebrospinal fluid (CSF) has been shown to be a sensitive method of diagnosing CMV disease in the central nervous system. Since CMV causes latent infection in white blood cells, an unanswered question is whether detection of latent CMV DNA in the cell fraction of CSF samples by PCR is possible in seropositive patients. In a prospective study, the finding of CMV DNA in CSF of CMV seropositive patients with suspected viral infection of the central nervous system (CNS) was evaluated clinically. Fractionation of 64 CSF samples from seropositive patients was carried out before analysing the samples for CMV DNA by PCR. In four of the five patients who had CMV DNA in the cell pellet and/or supernatant, the clinical data suggested CMV-associated neurological disease. The remaining 59 samples were negative in both pellet and supernatant. In addition, 11 CSF samples with high cell counts from patients with bacterial meningitis were examined for CMV DNA and found to be negative in 10 patients and positive in 1. One hundred thirty two uncentrifuged CSF samples were used as negative controls. The results of the study indicate that detection of CMV DNA in CSF samples by PCR correlated well with disease and was not due to latent CMV infection.

Quantitation of human cytomegalovirus (HCMV) DNA in cerebrospinal fluid by competitive PCR in AIDS patients with different HCMV central nervous system diseases

The current study was designed to quantitate human cytomegalovirus (HCMV) DNA in cerebrospinal fluid (CSF) of persons with AIDS with specific HCMV-related CNS disease. DNA present in CSF obtained from AIDS patients was initially detected by a qualitative PCR procedure and then quantitated using a competitive PCR assay. In a group of 21 AIDS patients with HCMV-related CNS disease, 12 patients with HCMV polyradiculopathy had a mean +/- SEM of 11,982 +/- 4,480 copies/microliters in their CSF compared to 1,747 +/- 929 for 9 patients with HCMV encephalitis p = 0.017). Of the 14 patients with > 1,000 copies/microliters of HCMV DNA in CSF, 11(79%) had HCMV polyradiculopathy including all 3 with > 10,000 copies/microliters. Ganciclovir treatment of 3 patients with HCMV-related CNS disease was associated with a decline in HCMV DNA detectable within CSF. These data indicate that quantities of HCMV DNA in CSF are higher in persons with HCMV-related polyradiculopathy than encephalitis, and that quantitation of HCMV DNA can be useful in monitoring antiviral therapy.