Use of a molecular probe for detecting JCV DNA directly in human brain material

Progressive multifocal leukoencephalopathy in myelodysplastic syndrome involving pure red cell aplasia

Progressive multifocal leukoencephalopathy (PML) is a rare and fatal demyelinating disease of the central nervous system caused by JC polyomavirus (JCV) reactivation in an immunocompromised host. We describe a case of PML in a 76-year-old woman with myelodysplastic syndrome, who had been treated with azathioprine for a pure red cell aplasia-like condition. PML was diagnosed based on the neurologic symptoms, the magnetic resonance imaging patterns and the detection of JCV DNA in the cerebrospinal fluid. She died ten months after the diagnosis. An autopsy confirmed the diagnosis, and JCV DNA was detected in the cerebrum. Azathioprine might have triggered PML.

Progressive multifocal leukoencephalopathy after rituximab therapy in HIV-negative patients: a report of 57 cases from the Research on Adverse Drug Events and Reports project

Rituximab improves outcomes for persons with lymphoproliferative disorders and is increasingly used to treat immune-mediated illnesses. Recent reports describe 2 patients with systemic lupus erythematosus and 1 with rheumatoid arthritis who developed progressive multifocal leukoencephalopathy (PML) after rituximab treatment. We reviewed PML case descriptions among patients treated with rituximab from the Food and Drug Administration, the manufacturer, physicians, and a literature review from 1997 to 2008. Overall, 52 patients with lymphoproliferative disorders, 2 patients with systemic lupus erythematosus, 1 patient with rheumatoid arthritis, 1 patient with an idiopathic autoimmune pancytopenia, and 1 patient with immune thrombocytopenia developed PML after treatment with rituximab and other agents. Other treatments included hematopoietic stem cell transplantation (7 patients), purine analogs (26 patients), or alkylating agents (39 patients). One patient with an autoimmune hemolytic anemia developed PML after treatment with corticosteroids and rituximab, and 1 patient with an autoimmune pancytopenia developed PML after treatment with corticosteroids, azathioprine, and rituximab. Median time from last rituximab dose to PML diagnosis was 5.5 months. Median time to death after PML diagnosis was 2.0 months. The case-fatality rate was 90%. Awareness is needed of the potential for PML among rituximab-treated persons.

Reduced rate of diagnostic positive detection of JC virus DNA in cerebrospinal fluid in cases of suspected progressive multifocal leukoencephalopathy in the era of potent antiretroviral therapy

Fifty-nine human immunodeficiency virus (HIV)-infected patients with suspected progressive multifocal leukoencephalopathy and 224 controls were tested for JC virus (JCV) DNA in cerebrospinal fluid by PCR. The diagnostic positive detection rate dropped from 89.5% (95% confidence intervals of 75.5 to 103.5%) in the pre-highly active antiretroviral therapy (HAART) era to 57.5% (95% confidence intervals of 42.1 to 72.9%) in the HAART era; the specificity remained unchanged. Predictors of failure to detect JCV DNA were exposure to HAART at disease onset and higher CD4 counts.

The JC virus antibody response in serum and cerebrospinal fluid in progressive multifocal leucoencephalopathy

BACKGROUND

A clinical diagnosis of progressive multifocal leucoencephalopathy (PML) can be confirmed by histological or virological examination of brain material. Whilst a less invasive method is provided by the detection of JC DNA in cerebrospinal fluid (CSF), very few studies have been done to assess the value of JC virus (JCV) serology in PML diagnosis.

OBJECTIVES

To study the JCV antibody response in the serum and CSF of PML patients.

STUDY DESIGN

A retrospective study was done using haemagglutination inhibition (HI), M-antibody capture radioimmunoassay (MACRIA) and JC-specific oligoclonal IgG banding on one or more sera and/or CSFs from 28 confirmed PML patients. Seventy-one serum and CSF samples were tested from patients with memory loss or dementia as a control group.

RESULTS

Twenty-seven PML patients (96%) had detectable JCV HI antibody in the serum, with titres ranging from 1 : 10 to > 1 : 20480, compared to 48 (68%) of the controls (P = <0.005). JCV IgM antibody was detected in the serum of 12/22 (55%) PML patients. JCV HI antibody was detected in the CSF in 12 of 18 (67%) PML patients, antibody index measurements being used to control for a possible breakdown of the blood-brain barrier. Intrathecal JCV antibody was not found in any control patient. Locally produced JCV-specific IgG bands were detected in the CSF of 7 PML patients tested, confirming the intrathecal origin and specificity of the HI antibody.

CONCLUSIONS

The presence of intrathecal JCV antibody indicates active central nervous system infection with JC virus, and provides a useful diagnostic test for PML, with a sensitivity of 67% and a specificity of 100%. The absence of serum JCV antibody nearly always excludes a diagnosis of PML, but the titre of antibody, IgG or IgM, correlates with the underlying condition rather than the development of neurological symptoms.

Papovavirus detection by electron microscopy in the brain of an elderly patient without overt progressive multifocal leukoencephalopathy

Virions resembling papovavirus were demonstrated in glial cells in the brain of an aged patient without overt progressive multifocal leukoencephalopathy. The patient was not in a severely immunocompromised state. On histological examination, only a few tiny incomplete necrotic foci were found in the subcortical area. These foci were widely dispersed. Rare, swollen oligodendroglial cells and astrocytes in which papovavirus capsid protein (VP-1) was demonstrated immunohistochemically were present around the foci. The two typical types of virus particles i.e. 35 to 40 nm round particles and elongated particles, were observed in the nuclei of the swollen glial cells. The latter were in the minority. Distinct crystals were also found in the nuclei. The centre-to-centre distance of the particles in the crystals, about 40 nm, and the electron-opaque spots of the round-shaped virions and of the elongated particles, were indicative of structural subunits of papovavirus capsids. This case provides further evidence that papovavirus, possibly JC virus, may be reactivated in the brains of aged patients who are not in an immunocompromised state.

Virological diagnosis of progressive multifocal leukoencephalopathy: detection of JC virus DNA in cerebrospinal fluid and brain tissue of AIDS patients

Cerebrospinal fluid (CSF) from 12 AIDS patients with clinical signs consistent with progressive multifocal leukoencephalopathy (PML) was examined by the polymerase chain reaction (PCR) for the presence of JC virus (JCV). A specific JCV target sequence was amplified in the CSF from 9 of the 12 patients and also in brain tissue from all nine JCV-positive patients. The clinical course, neuroimaging features, and, in four cases, histopathology of brain tissue proved that the nine patients had PML. In the other three patients with central nervous system disorders, the JCV genome was undetectable by PCR and Southern blot analysis in CSF and brain tissue. The clinical course and neuroimaging features ruled out PML in these three patients. Five CSF samples and five brain tissue specimens from 10 PML-free AIDS patients with central nervous system disorders were all negative for the JCV genome by PCR and Southern blot analysis. These results show that detection of JCV in CSF by PCR is a good alternative to brain tissue studies for the virological diagnosis of PML in AIDS patients.

JC virus DNA is present in many human brain samples from patients without progressive multifocal leukoencephalopathy

Sections of normal and diseased brain and kidney tissues were screened for the presence of JC virus (JCV) DNA by using the polymerase chain reaction. As expected, all samples obtained from patients with progressive multifocal leukoencephalopathy (PML) tested positive when multiple JCV-specific primer and probe combinations were used. Unexpectedly, more than 50% of non-PML-affected brains were also found to harbor low levels of JCV DNA. To confirm that the positive signals seen in the tissue sections were not the result of contamination, amplified DNA was cloned and sequenced and in some cases was shown to represent strains of JCV not identified previously. Two predominant regulatory region configurations of JCV have been detected in the human host: archetype JCV, which is excreted in the urine of normal and immunocompromised individuals, and "PML-type" JCV found in diseased brains. This latter group of variants appears to derive from archetype JCV by the deletion and duplication of sequences within the promoter-enhancer region. In the present study, the archetype strain of JCV was identified only in normal kidney samples; JCV DNA found in non-PML-affected brain specimens and in kidney tissue from patients with PML resembled that of strains isolated from PML-affected brain tissue. Our findings indicate that JCV reaches the brain more frequently than previously thought and may persist at this site without causing demyelinating disease. A subsequent episode of prolonged immunodeficiency or a direct interaction with an immunocompromising agent (e.g., human immunodeficiency virus type 1) might activate the latent JCV infection and lead to the development of PML.

Preparation of monoclonal antibodies to JC virus and their use in the diagnosis of progressive multifocal leucoencephalopathy

Seven monoclonal antibodies (MAbs) to polyomavirus JC were produced, and one was selected for use in immunofluorescence (IF) tests on brain material from patients with suspected progressive multifocal leucoencephalopathy (PML). The selected MAb (5.12.2) reacted by IF with JC-infected primary human foetal glial (PHFG) cell cultures (titre 1/200,000) but not with BK-infected human embryo lung (HEL) fibroblasts (titre less than 1/20). Its haemagglutination-inhibition (HI) titre was high (greater than 1/5 x 10(6)) against JC virus but low (less than 1/5) against BK virus. A diagnosis of PML was confirmed on brain biopsy or at postmortem in four patients, two of whom were also infected with human immunodeficiency virus (HIV). In one of the patients, specific detection of JC virus antigen had not been possible using our routine high titred JC and BK human sera due to interference by JC antibody present in the cerebrospinal fluid (CSF). Viral antigen was, however, detected with the MAb 5.12.2.

A single-step DNA extraction procedure for the detection of serum hepatitis B virus sequences by the polymerase chain reaction

A rapid single-step procedure for the isolation of low molecular weight DNA using guanidinium thiocyanate and phenol as protein denaturants is described and applied for the detection of specific hepatitis B virus (HBV) DNA sequences from serum samples by the polymerase chain reaction (PCR). The novel technique is efficient and, when compared to the standard proteinase K/phenol/chloroform method has the advantage of being faster and easily adaptable to the routine processing of a high number of clinical samples by PCR and spot hybridization techniques.

Detection of herpes simplex virus type 1 in herpetic ocular diseases by DNA-DNA hybridization using a biotinylated DNA probe

A diagnostic hybridization assay for detecting herpes simplex virus type 1 (HSV-1) in ocular specimens was developed using cloned viral DNA as a probe. This hybridization assay is based on visualizing a biotinylated probe that is hybridized to the target DNA by a streptavidin/alkaline phosphatase system. The time required for performing this assay system is only two days. This assay system could detect a probe which had been hybridized to as little as 1 pg of homologous DNA and did not cross-react with DNA of other human herpes viruses except that of herpes simplex virus type 2 (HSV-2) which showed weak cross-reactivity. The assay system was applied to experimental keratitis in albino rabbits and clinical specimens. In experimental keratitis in rabbits it was possible to detect HSV-1 DNA in the eye swab samples at least until the ninth day after virus inoculation. Five clinical specimens collected from patients with corneal ulcer or blepharitis contained HSV-1 DNA in spite of the failure of demonstration of viral antigen and/or virus isolation in two cases.

Diagnostic deoxyribonucleic acid probes for infectious diseases

Virtually all microorganisms contain some unique nucleotide sequences which can be the target of deoxyribonucleic acid probes. Probes have been used successfully to identify a wide variety of pathogens from the simple ribonucleic acid-containing polioviruses to the complex filarial worms Brugia malayi. Probe technology offers the clinical laboratory the potential both to extend the types of pathogens that can be readily identified and to reduce significantly the time associated with the identification of fastidious microorganisms. Over a dozen commercially prepared deoxyribonucleic acid probe tests are now available. This article explores the development of deoxyribonucleic acid probe tests and reviews the sensitivity, specificity, and predictive values of many of the diagnostic probes developed during the last several years. Prospects for newer, more sensitive detection systems for the products of hybridization reactions are also reviewed.