Orwik

Human immunodeficiency virus type 1 in the central nervous system leads to decreased dopamine in different regions of postmortem human brains.

Human immunodeficiency virus type 1 (HIV-1) invades the central nervous system (CNS) shortly after infection and becomes localized in varying concentrations in different brain regions, the most vulnerable is the basal ganglia (BG). It is hypothesized... expand abstract that HIV-1-mediated neuropathogenesis involves degeneration of dopaminergic neurons in the substantia nigra and the loss of dopaminergic terminals in the BG, leading to deficits in the central dopaminergic activity, resulting in progressive impairment of neurocognitive and motor functions. In the era of highly active antiretroviral therapy (HAART), although the incidence of HIV-associated dementia (HAD) has decreased, the neurocognitive and neuropsychological deficits continue to persist after HAART. In this study, We investigated the impact of HIV-1 on dopaminergic activity with respect to concentrations of dopamine (DA) and homovanillic acid (HVA) in different regions of postmortem human brains of HIV-1-negative and HIV-1+ individuals and their relationship to neurocognitive impairment. We found that in HIV-1+ as well as HIV-negative cases, dopamine and HVA concentrationsin ranged widely in different brain regions. In HIV-negative brain regions, the highest concentration of DA was found in putamen, caudate, substantia nigra, and the basal ganglia. In HIV-1+ cases, there was a significant decrease in DA levels in caudate nucleus, putamen, globus pallidus, and substantia nigra compared to that in HIV-negative cases. In HIV-1+ cases, a strong correlation was found between DA levels in substantia nigra and other brain regions. Concentration of HVA in HIV-negative cases was also highest in the regions containing high dopamine levels. However, no significant decrease in regional HVA levels was found in HIV-1+ cases. HIV-1 RNA load (nondetectable [ND] to log10 6.9 copies/g tissue) also ranged widely in the same brain regions of HIV-1+ cases. Interestingly, the brain regions having the highest HIV-1 RNA had the maximum decrease in DA levels. Age, gender, ethnicity, and postmortem interval were not correlated with decrease in DA levels. Profile of DA, HVA, and HIV-1 RNA levels in the brain regions of HIV-1+ individuals treated with HAART was similar to those not treated with HAART. A majority of HIV-1+ individuals had variable degrees of neurocognitive impairments, but no specific relationship was found between the regional DA content and severity of neurocognitive deficits. These findings suggest widespread deficits in dopamine in different brain regions of HIV-1-infected cases, and that these deficits may be the results of HIV-1-induced neurodegeneration in the subcortical regions of human brain. collapse abstract

Neurologic presentations of AIDS.

The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurre... expand abstractd an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome). collapse abstract

Neurocognition in individuals co-infected with HIV and hepatitis C.

Due to similar routes of viral transmission, many individuals infected with the human immunodeficiency virus (HIV) are also infected with the hepatitis C virus (HCV). Each virus can cause cognitive compromise among mono-infected individuals; evidence... expand abstract is accumulating that HIV/HCV co-infection may have a particularly deleterious impact on cognition. We present neuropsychological data obtained from 118 HIV+ adults with advanced HIV disease, 35 of whom were co-infected with HCV, who completed a comprehensive neurocognitive evaluation. Rates of global cognitive impairment were higher among co-infected patients than among those with HIV alone (63% vs. 43%). Within the specific domains of learning and memory, co-infected individuals were significantly more likely to be impaired than were the HIV mono-infected participants. Finally, we discuss implications of these findings and potential future directions for research in this area. collapse abstract

Microbial translocation is associated with increased monocyte activation and dementia in AIDS patients.

Elevated plasma lipopolysaccharide (LPS), an indicator of microbial translocation from the gut, is a likely cause of systemic immune activation in chronic HIV infection. LPS induces monocyte activation and trafficking into brain, which are key mechan... expand abstractisms in the pathogenesis of HIV-associated dementia (HAD). To determine whether high LPS levels are associated with increased monocyte activation and HAD, we obtained peripheral blood samples from AIDS patients and examined plasma LPS by Limulus amebocyte lysate (LAL) assay, peripheral blood monocytes by FACS, and soluble markers of monocyte activation by ELISA. Purified monocytes were isolated by FACS sorting, and HIV DNA and RNA levels were quantified by real time PCR. Circulating monocytes expressed high levels of the activation markers CD69 and HLA-DR, and harbored low levels of HIV compared to CD4(+) T-cells. High plasma LPS levels were associated with increased plasma sCD14 and LPS-binding protein (LBP) levels, and low endotoxin core antibody levels. LPS levels were higher in HAD patients compared to control groups, and were associated with HAD independently of plasma viral load and CD4 counts. LPS levels were higher in AIDS patients using intravenous heroin and/or ethanol, or with Hepatitis C virus (HCV) co-infection, compared to control groups. These results suggest a role for elevated LPS levels in driving monocyte activation in AIDS, thereby contributing to the pathogenesis of HAD, and provide evidence that cofactors linked to substance abuse and HCV co-infection influence these processes. collapse abstract

Calcification of the internal elastic lamina of coronary arteries.

Two well-recognized patterns of calcification occur in large- and medium-sized arteries, intimal calcification associated with atherosclerosis and medial calcification described by Mönckeberg. Calcification limited to the internal elastic lamina is a... expand abstract third pattern of calcification not previously reported in coronary arteries. Here we describe 19 cases of coronary artery internal elastic lamina calcification. We serially sectioned and examined the coronary arteries of 66 patients with advanced AIDS and 27 HIV- controls with other chronic illnesses. We observed calcification of the internal elastic lamina in 10 HIV+ patients and 9 controls. HIV- patients with internal elastic lamina calcification were significantly older than HIV- patients without it (P=0.008) and HIV+ patients with it (P=0.006). Occasionally, calcification encroached on adjacent intimal or medial tissue with mild fibrosis. There was frequent disruption of the internal elastic lamina but no evidence of inflammation. Calcification was the dominant histologic feature in all cases. Von Kossa, Alizarin red, and trichrome/elastic stains confirmed these findings. Patients with internal elastic lamina calcification often had extensive medical histories but did not suffer from chronic renal failure or other conditions known to cause calcium dysregulation. We describe coronary internal elastic lamina calcification in HIV+ patients and older HIV- adults. The clinical significance of this finding is unknown. It could lead to arterial stiffening and increased pulse pressure and could be mistaken for intimal calcification on coronary imaging. Internal elastic lamina calcification may result from premature aging due to HIV disease and chronic illness or from metabolic disorders in HIV+ patients. collapse abstract

NeuroAIDS: characteristics and diagnosis of the neurological complications of AIDS.

The neurological complications of AIDS (NeuroAIDS) include neurocognitive impairment and HIV-associated dementia (HAD; also known as AIDS dementia and HIV encephalopathy). HAD is the most significant and devastating central nervous system (CNS) compl... expand abstractications associated with HIV infection. Despite recent advances in our knowledge of the clinical features, pathogenesis, and neurobiological aspects of HAD, it remains a formidable scientific and therapeutic challenge. An understanding of the mechanisms of HIV neuroinvasion, CNS proliferation, and HAD pathogenesis provide a basis for the interpretation of the diagnostic features of HAD and its milder form, HIV-associated minor cognitive/motor disorder (MCMD). Current diagnostic strategies are associated with significant limitations, but it is hoped that the use of biomarkers may assist researchers and clinicians in predicting the onset of the disease process and in evaluating the effects of new therapies. collapse abstract

HIV-1 Antigens in Neurons of Cocaine-Abusing Patients.

Cocaine opens the blood-brain barrier by deregulating transcription of target genes. Here we show that cocaine at blood concentrations in drug abusers disrupts endothelial cell junctions in parallel with signaling by phosphorylation of extracellular ... expand abstractsignal-regulated kinase, myristoylated alanine-rich C kinase and myosin light chain. Cocaine effects may be important in vivo since the neurons of drug abusing patients with HIV-1 associated dementia displayed gp120, p24 and Nef. collapse abstract

Coronary atherosclerotic lesions in human immunodeficiency virus-infected patients: a histopathologic study.

BACKGROUND: Studies suggest human immunodeficiency virus-positive (HIV+) patients have an increased risk of coronary artery disease (CAD), yet little is known about the histopathology, severity, or distribution of lesions. METHODS: The coronary arter... expand abstracties of 66 deceased AIDS patients and 19 HIV controls (age <55) were dissected and graded for percent luminal stenosis by intimal lesions, percent of intima involved with lipid, and extent of intimal calcification on a scale of 0 to 3. Medical histories, antiretroviral therapies, and CAD risk factors were reviewed. RESULTS: HIV+ patients were older than controls (P=.06), and more were male (P=.02). Thirty-five percent of HIV+ patients had stenosis >or=75% of at least one artery. Compared to controls, HIV+ patients had three times greater odds of stenosis >or=75%, controlling for age and sex (one-sided P=.03). Older age and male sex were also risk factors (one-sided P<.001). HIV seropositivity was associated with increased plaque lipid content (one-sided P=.02) and calcification (one-sided P=.08). Duration of HIV infection, antiretroviral therapy, and immune status did not predict severe disease in multivariate analyses. Previously unreported patterns of dystrophic calcification were observed in HIV+ patients and older controls. CONCLUSIONS: Young to middle-aged patients dying from advanced AIDS have atherosclerotic CAD that may result in luminal narrowing, heavy calcification, and high plaque lipid content. The pattern of disease, location of lesions, and plaque composition are typical of atherosclerosis in HIV-negative patients. No relationship between antiretroviral therapies and atherosclerosis was seen in this small study of heavily treated patients. collapse abstract

The Role of Host Genetics in the Susceptibility for HIV-associated Neurocognitive Disorders.

Despite progress in the treatment of the Human Immunodeficiency virus (HIV), there continues to be a high prevalence of infected individuals who develop neurocognitive deficits and disorders. Our understanding of the potential cause of HIV-associated... expand abstract neurocognitive disorders (HAND) continues to develop on many fronts. Among them is the study of host genetics. Here, we review the most current information regarding the association between host genetics and risk for HIV infection, AIDS, and HAND. We focus on the role of dopamine dysfunction in the etiology of HAND, and propose a number of genetic polymorphisms within genes related to dopaminergic functioning and other neurobiological factors that may confer vulnerability or protection against HAND. collapse abstract

An exploratory study of long-term neurocognitive outcomes following recovery from opportunistic brain infections in HIV+ adults.

Central nervous system opportunistic infections (CNS-OI) are a significant cause of morbidity and mortality in AIDS. While current interventions are increasingly successful in treating CNS-OI, little information exists regarding long-term behavioral ... expand abstractoutcomes among survivors. In this exploratory study we examined neurocognitive data among three groups of adults with different AIDS-related CNS-OI: 15 with past cryptococcal meningitis (CM), 8 with toxoplasmosis encephalitis (TE), and 8 with progressive multifocal leukoencephalopathy (PML). A group of 61 individuals with AIDS, but without CNS-OI, was used as a comparison group. A battery of standardized neuropsychological tests assessing a variety of cognitive domains was administered upon entry. Results indicate that individuals with a history of CNS-OI were most impaired on measures of cognitive and psychomotor speed relative to the HIV+ comparison group. Among the CNS-OI groups, individuals with history of TE had the most severe and varied deficits. The results are discussed in relation to what is known about the neuropathological consequences of the various CNS-OIs. While this is the first systematic group study of residual CNS-OI effects on neurocognitive function, future studies employing more participants, perhaps focusing on specific CNS-OIs, will further characterize the long-term outcomes in AIDS-related CNS-OI. collapse abstract

Interrater reliability of the Psychiatric Research Interview for Substance and Mental Disorders in an HIV-infected cohort: experience of the National NeuroAIDS Tissue Consortium.

The interrater reliability of the Psychiatric Research Interview for Substance and Mental Disorders (PRISM) was assessed in a multicentre study. Four sites of the National NeuroAIDS Tissue Consortium performed blinded reratings of audiotaped PRISM in... expand abstractterviews of 63 HIV-infected patients. Diagnostic modules for substance-use disorders and major depression were evaluated. Seventy-six per cent of the patient sample displayed one or more substance-use disorder diagnoses and 54% had major depression. Kappa coefficients for lifetime histories of substance abuse or dependence (cocaine, opiates, alcohol, cannabis, sedative, stimulant, hallucinogen) and major depression ranged from 0.66 to 1.00. Overall the PRISM was reliable in assessing both past and current disorders except for current cannabis disorders when patients had concomitant cannabinoid prescriptions for medical therapy. The reliability of substance-induced depression was poor to fair although there was a low prevalence of this diagnosis in our group. We conclude that the PRISM yields reliable diagnoses in a multicentre study of substance-experienced, HIV-infected individuals. collapse abstract

Interrater reliability of clinical ratings and neurocognitive diagnoses in HIV.

We examined the interrater (IRR) of clinical ratings of neuropsychological (NP) impairment and neurocognitive diagnoses in HIV. Thirty participants with advanced HIV-infection who were enrolled in a multicenter HIV brain banking research project unde... expand abstractrwent comprehensive NP and neuromedical evaluations. Using a standardized system of guidelines, neuropsychologists from six participating sites independently assigned clinical ratings of NP impairment, as well as multilevel diagnoses reflecting the inferred etiology of the impairments and their effects on everyday functioning. Findings indicated excellent IRR in rating the presence and severity of NP impairment, but overall modest IRR for neurocognitive diagnoses. Not surprisingly, most diagnostic disagreements concerned the etiology of impairments in persons with medical and neuropsychiatric risk factors in addition to HIV. collapse abstract

Patient page. A new clue in the mystery of neuro-AIDS.

Stability of human immunodeficiency virus type 1 RNA in cerebrospinal fluid determined with the AMPLICOR HIV-1 MONITOR test, version 1.5 (ultrasensitive).

We evaluated the effects of time, temperature, freezing, and thawing on the cerebrospinal fluid viral load by using the Roche AMPLICOR HIV-1 MONITOR test, version 1.5 (ultrasensitive). While a statistically significant decrease from the baseline was ... expand abstractobserved at 24 h, but not at 6 or 12 h, and with one freeze-thaw cycle, all changes were within the range of intra-assay variability. collapse abstract

The National NeuroAIDS Tissue Consortium: a new paradigm in brain banking with an emphasis on infectious disease.

The National NeuroAIDS Tissue Consortium (NNTC) was founded in 1998, in response to the scientific need for well-characterized central nervous system (CNS) and peripheral nervous system (PNS) tissues and fluids from HIV-infected individuals. In addit... expand abstraction to performing the routine functions of non-transplant anatomic tissue banks, the Consortium offers a unique model for the integration of independent research entities in order to provide well-characterized tissues and fluids for the international research community. Herein, we describe the structure of the Consortium, pointing out the inherent strengths of linking together multiple independent sites for the purpose of banking HIV-infected nervous system tissues. We describe the neuropathology protocol that was adopted and successfully implemented at the four participating banks of the Consortium. collapse abstract

Influence of JC virus coding region genotype on risk of multiple sclerosis and progressive multifocal leukoencephalopathy.

Two features of the biology of JC virus make it a particularly suitable candidate for an agent in MS-like disease: its neurotropic capability targeting glial cells as evidenced in progressive multifocal leukoencephalopathy lesions, and its capacity f... expand abstractor latency and persistence as illustrated by its behaviour in the kidney. JC virus is chronically or intermittently excreted in the urine by some 40% of the population. The existence of JC virus in multiple coding-region genotypes provides a unique approach to the study of JC virus-induced neurological disease. We have previously shown that a genotype originating in Asia but also present in Europe and the US, called Type 2B, is more frequently found in PML brain than expected based on its prevalence in urine samples from a control population. In contrast, we find that the excretion of JCV in MS patients is similar in both genotype and frequency to that of control individuals, and appears to be regulated by factors unrelated to those that control CNS disease activity. collapse abstract

A phase II trial of nerve growth factor for sensory neuropathy associated with HIV infection. AIDS Clinical Trials Group Team 291.

OBJECTIVE: To evaluate the safety and efficacy of recombinant human nerve growth factor (rhNGF) in HIV-associated sensory neuropathy (SN) within a multicenter, placebo-controlled, randomized trial (ACTG 291). BACKGROUND: SN affects 30% of individuals... expand abstract with AIDS, is worsened by neurotoxic antiretrovirals, and its treatment is often ineffective. NGF is trophic for small sensory neurons and stimulates the regeneration of damaged nerve fibers. METHODS: A total of 270 patients with HIV-associated SN were randomized to receive placebo, 0.1 microg/kg rhNGF, or 0.3 microg/kg rhNGF by double-blinded subcutaneous injection twice weekly for 18 weeks. The primary outcome was change in self-reported neuropathic pain intensity (Gracely Pain Scale). Secondary outcomes included an assessment of global improvement in neuropathy by patients and investigators, neurologic examination, use of prescription analgesics, and quantitative sensory testing. In a subset, epidermal nerve fiber densities were determined in punch skin biopsies. RESULTS: Both doses of NGF produced significant improvements in average and maximum daily pain compared with placebo. Positive treatment effects were also observed for global pain assessments (p = 0.001) and for pin sensitivity (p = 0.019). No treatment differences were found with respect to mood, analgesic use, or epidermal nerve fiber densities. Injection site pain was the most frequent adverse event, and resulted in unblinding in 39% of subjects. Severe transient myalgic pain occurred in eight patients, usually from accidental overdosing. There were no changes in HIV RNA levels or other laboratory indices. CONCLUSIONS: We found a positive effect of recombinant human nerve growth factor on neuropathic pain and pin sensitivity in HIV-associated sensory neuropathy. rhNGF was safe and well tolerated, but injection site pain was frequent. collapse abstract

JC virus type 2B is found more frequently in brain tissue of progressive multifocal leukoencephalopathy patients than in urine from controls.

OBJECTIVES: Previous studies have shown that strains of human polyomavirus JC (JCV) of Asian origin (type 2) are much more highly represented in progressive multifocal leukoencephalopathy (PML) brain than would be expected from their frequency of exc... expand abstractretion in urine samples of a comparable control group. The present studies were designed to test whether one subtype of type 2 was preferentially elevated. STUDY DESIGN/METHODS: The statistical relation between JCV subtypes represented in PML brain tissue from 51 probands and those in urine samples from 115 control individuals was examined. RESULTS: The proportion of the JCV subtype 2B in PML brain (36%) was highly significantly increased relative to its occurrence in control urine samples (5.9%; P < .001). Type 1 and its subtypes were not different in the PML brain and control urine cohorts. The number of type 4 strains in PML brains was reduced, although the difference did not reach statistical significance (P = .08). CONCLUSIONS: The results predict that the human immunodeficiency virus (HIV)-positive individuals at highest risk of PML infection are those carrying the JCV genotype known as type 2B. Prospective studies will be required to confirm this finding. collapse abstract

HAART improves prognosis in HIV-associated progressive multifocal leukoencephalopathy.

Introduction of highly active antiretroviral therapy (HAART) has been associated with many changes in the complications of human immunodeficiency virus (HIV) infection. A cohort of 25 HIV patients with progressive multifocal leukoencephalopathy (PML)... expand abstract treated with HAART experienced a median survival of >46 weeks. This is an improvement in prognosis compared with recent historic experience and correlated with HIV RNA viral load reductions. We conclude that current HIV therapy is important in improving the outlook of PML in the setting of HIV. collapse abstract

JC virusType 2: definition of subtypes based on DNA sequence analysis of ten complete genomes.

Five major genotypes of JC virus (JCV) have been defined based on nucleotide differences in the VP1 gene of the DNA sequence. These types are probably a result of virus evolution in geographically isolated population groups. One of the first genotype... expand abstracts identified, Type 2, was found to represent strains of Asian origin. In order to further define the spectrum within Type 2 strains, the entire 5.1 kb genome of nine urinary strains of JCV was amplified by PCR with one pair of primers. These urine samples were obtained in the USA (California and New Mexico) from three European Americans, three Native Americans, two African Americans and one Hispanic American. The complete genome of an Asian JCV strain (Tokyo-1) isolated from progressive multifocal leukoencephalopathy (PML) brain in Japan was also sequenced. Here, we report the analysis of these ten DNA sequences and their deduced protein translations. Two phylogenetically distinct subtypes of Type 2 were found, 2A and 2B, which differ from each other by 0.8-1.1% of the coding region sequence. A 215 bp product amplified with primers in the VP1 gene contains enough sequence information to distinguish the major types and subtypes of JCV and is suitable for application in viral epidemiological studies. The investigation of these genomic variations is of special interest because JCV Type 2 strains are found at a significantly higher frequency in brain tissue of patients with PML than would be predicted from their excretion in a control population. collapse abstract

JC virus (JCV) genotypes in brain tissue from patients with progressive multifocal leukoencephalopathy (PML) and in urine from controls without PML: increased frequency of JCV type 2 in PML.

Progressive multifocal leukoencephalopathy (PML) is caused by the human polyomavirus JC (JCV), and there are at least 4 different genotypes of JCV in the United States. Type 1 strains are of European origin, whereas type 2 and 3 strains are of Asian ... expand abstractand African origin, respectively. JCV type 4 strains are derived from a type 1/3 recombinant. In this study, the genotype distribution of JCV strains found in brain tissue or cerebrospinal fluid of 50 PML patients was compared with JCV genotypes excreted in the urine of 103 control subjects. Type determination was based on the polymerase chain reaction-amplified partial sequence of the VP1 coding gene and the noncoding region left of ori. Brain tissues from patients with PML were infected with a significantly higher proportion of JCV type 2 strains than were urine samples from the control group (P = .004). This evidence indicates a biologic difference between JCV genotypes and suggests a difference in their potential to cause PML. collapse abstract

JC virus regulatory region rearrangements and genotypes in progressive multifocal leukoencephalopathy: two independent aspects of virus variation.

JC virus (JCV) causes the central demyelinating disease progressive multifocal leukoencephalopathy (PML). JCV strains excreted in the urine are distinguishable from those in PML tissue by the configuration of their regulatory region to the right of o... expand abstractri: the archetypal regulatory region, 267 nucleotides long, is rearranged in PML tissue by deletion and duplication. Within the coding region JCV shows variations as a result of virus evolution. Four major genotypes are distinguishable of which Type 1 is based in Europe and Type 2 in Asia. Here, the regulatory region rearrangements and the viral genotypes of 29 JCV strains from PML brain were determined. Rearrangement patterns and genotypes were not associated. In general, deletions occurred before duplications, but exceptions to this rule exist. Each configuration of the 29 rearranged regulatory regions was unique and could be derived directly from the non-rearranged, archetypal form. collapse abstract

Headache in ambulatory HIV-1-infected men enrolled in a longitudinal study.

OBJECTIVE: To report headache (HA) data collected from subjects in a longitudinal study of human immunodeficiency virus (HIV)-1 and the central nervous system (CNS) DESIGN/METHODS: Baseline data from 229 ambulatory HIV-seropositive (HIV+) and 53 sero... expand abstractnegative control subjects were analyzed. Subjects were classified by the presence or absence of HIV-1-associated HAs and HIV-1-associated systemic and neurologic disease. Subjects were followed longitudinally for up to 5 years. RESULTS: In the cross-sectional analysis, significant associations were observed between HIV-1-associated HAs and (1) anxiety and depression, and (2) a history of drug use, psychiatric disease, and non-HIV-1 neurologic disease. No significant differences in laboratory values were found between subjects with HIV-1-associated HA compared with those without HA. When HIV+ subjects were followed longitudinally, onset of new HIV-1-associated systemic or neurologic disease over 1 year was not predicted by the presence of an HIV-1-associated HA at baseline. CONCLUSION: Headaches are common in HIV+ persons at all stages of disease. Presence of HIV-1-associated HAs at baseline were not associated with neurologic disease progression over 1 year of follow-up in our sample. collapse abstract

Co-infection with two JC virus genotypes in brain, cerebrospinal fluid or urinary tract detected by direct cycle sequencing of PCR products.

The human polyomavirus JC (JCV), which exists in different geographically based genotypes, causes the central demyelinating disease known as progressive multifocal leukoencephalopathy (PML). A coding region recombinant JCV Type 1/Type 3 (Type 4) is e... expand abstractxcreted in the urine of some 16% of individuals in the USA. In addition, occasional 'crossovers' in viral DNA sequence at type-specific sites in the coding region occur between JCV genotypes amplified from PML brain. For recombination to occur requires the existence of two different genotypes in the same host. Here we provide evidence from direct cycle sequencing of PCR products that different genotypes of JCV can be found in a single tissue sample. After non-type-specific PCR amplification, cycle sequencing produced 'split bands' at type determining sites which were resolved into type or subtype-specific sequences by subcloning of the PCR products. PCR products with split bands at typing sites were found in two brain samples and in one cerebrospinal fluid (CSF) from AIDS patients with PML and in the urine of four immunocompetent individuals. This indicates that co-infection with two viral types does not depend on severe immunocompromise. Combinations of genotypes found were Types 1A & 1B, 1A & 2, 1B & 2 and 2 & 3. In one doubly infected patient the major JCV type excreted in the urine changed within 1 week. collapse abstract

Quantifying HIV-1 RNA using the polymerase chain reaction on cerebrospinal fluid and serum of seropositive individuals with and without neurologic abnormalities.

We quantified HIV-1 RNA levels (copies per milliliter) in cerebrospinal fluid (CSF) and serum from subjects at various stages of HIV-1 disease and determined the relationship of RNA levels to clinical and neurologic disease status (HND) and to labora... expand abstracttory values. Ninety-seven HIV-1-seropositive men without CNS opportunistic infections, tumors, or neurosyphilis and 13 high-risk seronegative controls were included in the study. Each individual underwent a structured interview and physical and neurologic examinations, followed by standardized collection of blood and CSF. A custom-designed, fully automated polymerase chain reaction (PCR) system was used to perform a minimum of four separate amplifications per specimen, using two HIV-1 gag primer pairs. Southern blotting followed by hybridization with product-specific probes was used for post-PCR detection. The number of copies per milliliter was determined by relating unknowns to a built-in dilution-series standard curve using an image analysis system. HIV-1 RNA was detectable in 96% of the sera, 78% of the concentrated CSF samples, and 54% of the unconcentrated CSF samples. Serum RNA levels were significantly higher than in CSF. Serum RNA levels were significantly inversely correlated with CD4+ cell counts (p = -0.34; p = 0.03): i.e., higher RNA levels in seropositive subjects were associated with lower numbers of CD4+ cells. Serum RNA levels correlated positively with number of AIDS-related symptoms, dysfunction scores for total neurological examination, mental status score, cranial nerve score, and CNS motor signs score. Serum RNA levels did not correlate significantly with length of time on zidovudine therapy, intrathecal IgG synthesis rate, or albumin leakage. RNA levels in CSF significantly correlated only with intrathecal IgG synthesis rate and with serum RNA levels. These results confirm that serum levels of HIV-1 RNA correlate with HND and inversely correlate with CD4 counts, demonstrating that HND occurs predominantly in late stages of HIV-1 disease, although HIV-1 RNA can be detected in CSF from a majority of HIV-1-seropositive individuals at all stages of disease, which suggests that there can be early penetration of HIV into the CNS. However, HND can occur in the absence of high levels of CSF HIV-1 RNA. We also found that the concentration of HIV-1 in CSF is correlated with intrathecal IgG synthesis rate. collapse abstract