Pathology of the central nervous system in patients infected with the human immunodeficiency virus (HIV): a report of 252 autopsy cases from Brazil

AIDS-related cytomegalovirus encephalitis in the late ART era: A retrospective cohort study at a referral center in Brazil

BACKGROUND

AIDS-related cytomegalovirus (CMV) encephalitis has declined in the combined antiretroviral therapy (ART) era in high-income countries. However, there is scarce information on CMV encephalitis in low- and middle-income countries. The objectives of this study were to identify the prevalence of AIDS-related CMV encephalitis and describe its main features.

METHODS

This was a retrospective cohort study carried out at a referral center in São Paulo, Brazil. We included adult people living with HIV/AIDS (PLWHA), hospitalized in 2019, with a CD4 cell count ≤100/mm³ and quantitation CMV DNA results in plasma. Cases with compatible neurological manifestations and detection of CMV DNA by polymerase chain reaction (PCR) in cerebrospinal fluid samples were defined as CMV encephalitis.

RESULTS

Among 761 PLWHA hospitalized, 248 (32.5%) cases were included in this study. Prevalence of CMV encephalitis was 2.4% (6/248) among all included cases and 7.7% (6/78) among individuals with neurological opportunistic diseases. The six patients with CMV encephalitis were males and had CD4 cell count <50/mm³. Five (83%) cases had CMV encephalitis as AIDS-defining disease and showed CMV DNA detection by PCR >50,000 UI/mL plasma. All six cases received anti-CMV therapy (ganciclovir, n = 4; ganciclovir plus foscarnet, n = 2) and five were discharged to home. CMV encephalitis was not uncommon among hospitalized PLWHA with neurological opportunistic diseases.

CONCLUSIONS

The epidemiological and immunological profile of individuals with CMV encephalitis was similar to that described in the pre-ART era, but in contrast, most cases were treated and discharged from the hospital.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Mortality by cryptococcosis in Brazil from 2000 to 2012: A descriptive epidemiological study

BACKGROUND

Cryptococcosis is a neglected and predominantly opportunistic mycosis that, in Brazil, poses an important public health problem, due to its late diagnosis and high lethality.

METHODS

The present study analysed cryptococcosis mortality in Brazil from January 2000 to December 2012, based on secondary data (Mortality Information System/SIM-DATASUS and IBGE).

RESULTS

Out of 5,755 recorded deaths in which cryptococcosis was mentioned as one of the morbid states that contributed to death, two distinct groups emerged: 1,121 (19.5%) registered cryptococcosis as the basic cause of death, and 4,634 (80.5%) registered cryptococcosis associated with risk factors, mainly AIDS (75%), followed by other host risks (5.5%). The mortality rate by cryptococcosis as the basic cause was 6.19/million inhabitants, whereas the mortality rate by cryptococcosis as an associated cause was 25.19/million inhabitants. Meningitis was the predominant clinical form (80%), males were the more affected (69%), and 39.5 years old was the mean age. The highest mortality rate due to cryptococcosis as basic cause occurred in the state of Mato Grosso (10.96/million inhabitants). Mortality rates due to cryptococcosis as associated cause were highest in the states of Santa Catarina (70.41/million inhabitants) and Rio Grande do Sul (64.40/million inhabitants), both in the South Region. Southeast, Northeast and South showed significant time trends in mortality rates.

CONCLUSIONS

This study is relevant because it shows the magnitude of cryptococcosis mortality linked to AIDS and removes the invisibility of a particular non-AIDS-related disease, accounting for almost 20% of all cryptococcosis deaths. It can also contribute to control and surveillance programs, beyond highlighting the urgent prioritization of early diagnosis and proper treatment to reduce the unacceptable mortality rate of this neglected mycosis in Brazil.

HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Quality of life and handgrip strength of HIV patients diagnosed with neurotoxoplasmosis

Abstract HIV / AIDS epidemic continues to be a major public health problem, and when there is poor adherence to treatment, patients become susceptible to other infections such as toxoplasmosis. The aim of this study was to evaluate the handgrip strength and quality of life of HIV infected patients diagnosed with neurotoxoplasmosis. A cross-sectional study was conducted with 40 HIV-infected patients, with and without diagnosis of neuroxoplasmosis.Sociodemographic and clinical profile information was collected, and handgrip strength and quality of life were evaluated. Almost all patients of both groups used antiretroviral therapy. In the handgrip strength evaluation, no statistical difference was observed for the right and left hand between groups with and without neurotoxoplasmosis (p> 0.05). However, the classifica-1 Federal University of Pará. Gradution of inadequate handgrip strength in the neurotoxoplasmosis group was significantly higher.ate Program in Tropical Diseases. In the quality of life domain, it was observed that financial concern had lower scores in the Belém, PA. Brazil. group with neurotoxoplasmosis (p = 0.0379). It was observed that neurotoxoplasmosis showedno association with epidemiological, clinical, handgrip strength and quality of life variables.2 State University of Pará. Center However, patients with neurotoxoplasmosis showed a trend towards lower muscle strength.

Toxoplasmosis in humans and animals in Brazil: high prevalence, high burden of disease, and epidemiology

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Brazil. The burden of clinical toxoplasmosis in humans is considered to be very high. The high prevalence and encouragement of the Brazilian Government provides a unique opportunity for international groups to study the epidemiology and control of toxoplasmosis in Brazil. Many early papers on toxoplasmosis in Brazil were published in Portuguese and often not available to scientists in English-speaking countries. In the present paper we review prevalence, clinical spectrum, molecular epidemiology, and control of T. gondii in humans and animals in Brazil. This knowledge should be useful to biologists, public health workers, veterinarians, and physicians. Brazil has a very high rate of T. gondii infection in humans. Up to 50% of elementary school children and 50-80% of women of child-bearing age have antibodies to T. gondii. The risks for uninfected women to acquire toxoplasmosis during pregnancy and fetal transmission are high because the environment is highly contaminated with oocysts. The burden of toxoplasmosis in congenitally infected children is also very high. From limited data on screening of infants for T. gondii IgM at birth, 5-23 children are born infected per 10 000 live births in Brazil. Based on an estimate of 1 infected child per 1000 births, 2649 children with congenital toxoplasmosis are likely to be born annually in Brazil. Most of these infected children are likely to develop symptoms or signs of clinical toxoplasmosis. Among the congenitally infected children whose clinical data are described in this review, several died soon after birth, 35% had neurological disease including hydrocephalus, microcephaly and mental retardation, 80% had ocular lesions, and in one report 40% of children had hearing loss. The severity of clinical toxoplasmosis in Brazilian children may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil.

Co-infection of HIV and tropical infectious agents that affect the nervous system

Tropical infections refer to a group of diseases usually located in regions with a warm climate, particularly affecting developing countries, partly because of the conditions that allow them to thrive. However, due to the increased international travel, infectious agents that were previously limited to tropical regions pose an increasing threat to populations at risk for opportunistic infection (OI), especially those infected with the HIV. Tropical infections can facilitate HIV transmission and accelerate the progression of asymptomatic HIV infection to AIDS. Some have the potential to alter the epidemiology, natural history, and/or response to treatment of the other. The introduction of highly active antiretroviral therapy has provided a huge benefit for the vast majority of patients infected with the HIV, by allowing the immune system to recover, improving the clinical and radiological results and reducing the number of OI. On the other hand, some patients have developed various disorders of immune reconstitution, resulting in either hyper-immune inflammatory response to an exogenous antigen or autoimmunity. A significant proportion of these cases have been reported in immigrants from tropical countries to high-income countries, therefore awareness of these phenomena is needed since clinical presentations are often atypical and pose diagnostic challenges. This article reviews some of the key diagnostic aspects of tropical infections associated with HIV infection.

Neuropathology of AIDS: An Autopsy Review of 284 Cases from Brazil Comparing the Findings Pre- and Post-HAART (Highly Active Antiretroviral Therapy) and Pre- and Postmortem Correlation

A retrospective study of central nervous system (CNS) in 284 autopsy AIDS cases in Brazil (1989–2008) divided into 3 groups: A (without antiretroviral treatment: 163 cases); B (other antiretroviral therapies: 76 cases); C (HAART for 3 months or more: 45 cases). In 165 (58.1%) cases, relevant lesions were found, predominantly infections (54.2%); the most frequent was toxoplasmosis (29.9%) followed by cryptococcosis (15.8%), purulent bacterial infections (3.9%), and HIV encephalitis (2.8%); non-Hodgkin lymphomas occurred in 1.4% and vascular lesions in 1.1%. There was no difference when compared the frequency of lesion among the groups; however, toxoplasmosis was less common while HIV encephalitis was more frequent in group C related to A. CNS lesions remain a frequent cause of death in AIDS; however, the mean survival time was four times greater in group C than in A. In 91 (55.1%) of 165 cases with relevant brain lesions (or 32% of the total 284 cases), there was discordance between pre- and postmortem diagnosis; disagreement type 1 (important disease that if diagnosed in life could change the patient prognosis) occurred in 49 (53.8%) of 91 discordant cases (17.6% of the total 284) indicating the autopsy importance, even with HAART and advanced diagnostics technologies.

Aids-related progressive multifocal leukoencephalopathy: a retrospective study in a referral center in São Paulo, Brazil

Few data are available about progressive multifocal leukoencephalopathy (PML) in patients with acquired immunodeficiency syndrome (AIDS) from Brazil. The objectives of this study were to describe the main features of patients with PML and estimate its frequency among AIDS patients with central nervous system (CNS) opportunistic diseases admitted to the Instituto de Infectologia Emílio Ribas, São Paulo, Brazil, from April 2003 to April 2004. A retrospective and descriptive study was performed. Twelve (6%) cases of PML were identified among 219 patients with neurological diseases. The median age of patients with PML was 36 years and nine (75%) were men. Nine (75%) patients were not on antiretroviral therapy at admission. The most common clinical manifestations were: focal weakness (75%), speech disturbances (58%), visual disturbances (42%), cognitive dysfunction (42%), and impaired coordination (42%). The median CD4+ T-cell count was 45 cells/µL. Eight (67%) of 12 patients were laboratory-confirmed with PML and four (33%) were possible cases. Eleven (92%) presented classic PML and only one case had immune reconstitution inflammatory syndrome (IRIS)-related PML. In four (33%) patients, PML was the first AIDS-defining illness. During hospitalization, three patients (25%) died as a result of nosocomial pneumonia and nine (75%) were discharged to home. Cases of PML were only exceeded by cases of cerebral toxoplasmosis, cryptococcal meningoencephalitis, and CNS tuberculosis, the three more frequent neurologic opportunistic infections in Brazil. The results of this study suggest that PML is not an uncommon HIV-related neurologic disorder in a referral center in Brazil.

Bacterial infections

The organisms that produce bacterial infections of the nervous system in tropical regions are similar to those existing in the rest of the world. However, because of poor socio-economic conditions in the former areas, preventing the implementation of appropriate prophylactic and therapeutic measures, the incidence and course of these diseases may vary. In this paper the neuropathological appearances of the main bacterial diseases are reviewed and the main differences between those occurring in developed and developing countries emphasized. Despite great efforts by governments and communities, tuberculosis still remains a scourge in many countries and leprosy has not been eradicated from earth. Earlier optimism that antibiotics could finally put an end to syphilis have been dashed and the disease still persists. Moreover, the explosion of AIDS not only has produced a recrudescence of many of these diseases, but has also changed their clinical and pathological presentation.

Infectious diseases in paediatric pathology: experience from a developing country

Infectious and parasitic diseases have always challenged man. Although many of them are typically seen in some areas of the world and can be adequately managed by just improving socioeconomic status and sanitary conditions, they are still quite prevalent and may sometimes be seen outside their original geographical areas. Human migration due to different reasons, tourism, blood transfusion and solid organ transplantation has created new concerns for health professionals all over the world. If not for diagnostic purposes, at least these tropical and infectious diseases should be largely known because their epidemiology, pathogenesis, host/parasite interaction, inflammatory and reparative responses are quite interesting and teach us about human biology. Curiosity is inherent to pathology practice and so we are compelled to look for things other than tumours or degenerative diseases. This review focuses on infectious and parasitic diseases found in a developing country and brings up-to-date information on diseases caused by viruses (dengue, yellow fever), bacteria (typhoid fever, leprosy), parasites (Chagas' disease, cutaneous and visceral leishmaniasis, amoebiasis, Capillaria hepatica, schistosomiasis, cysticercosis) and caused by fungi (paracoccidioidomycosis, cryptococcosis, histoplasmosis) that may be useful for pathologists when facing somewhat strange cases from developing countries.

Cytomegalovirus retinitis: the neglected disease of the AIDS pandemic

The authors describe CMV retinitis in resource-poor settings and suggest possibilities for management.

Infection as a risk factor for stroke

Persisting disability requiring professional healthcare or help in daily life activities can be expected in a third to a half of all stroke survivors. It is mainly the elderly that are affected. For the increasingly aging population of Western societies, stroke represents an increasing social and economic burden. Besides the existing therapeutic options, additional treatment and prevention strategies are needed. Traditional risk factors do not explain all clinical and epidemiological features of stroke. Recently, the association between infectious and inflammatory processes and the occurrence of vascular disease has been established. This review summarizes the current evidence of infections as stroke risk factors and of potential anti-infective strategies as future methods of stroke prevention.

Degenerative and inflammatory lesions in sympathetic ganglia: further morphological evidence for an autonomic neuropathy in AIDS

There is accumulating evidence that autonomic dysfunction occurs in HIV infection. While many studies have demonstrated autonomic abnormalities on clinical basis, only one has studied the morphology of sympathetic ganglia. The superior sympathetic ganglia of 12 randomly selected AIDS patients and those of 6 controls were examined morphologically in order to determine the frequency and severity of their involvement. Although they had not been investigated for autonomic dysfunction, 5 had suffered from non-infectious diarrhoea, one showed bilateral ptosis and another had non-specified visual problems. All cases showed clusters, and perivascular mononuclear inflammatory cells, occasionally infiltrating vessel walls, some evidence of nerve cell degeneration, and proliferation of capsule cells. Immunostainings showed T lymphocytes and an increased number of macrophages. HIV antigens were detected in macrophages, in 6 cases (50%). This study provides further morphological support for the autonomic dysfunction in association with HIV infection. As for the mechanism of this dysfunction, it has been postulated a direct infection, the virus entering the ganglia through macrophages and acting as a reservoir for HIV, and an autoimmune pathogenesis. Since HIV antigens were not detected in 50% of the cases in this and in a previous study, despite the existence of morphological lesions, it is possible that, as in HIV-related sensory-motor peripheral neuropathies, an autoimmune mechanism may also play a role in the development of the autonomic lesions.

Neurological disease in HIV-infected patients in the era of highly active antiretroviral treatment: a Brazilian experience

To study characteristics of neurological disorders in HIV/AIDS patients and their relationship to highly active antiretroviral treatment, a cross-sectional study was conducted in an infectious disease public hospital in Belo Horizonte, Brazil, between February 1999 and March 2000. Of the 417 patients enrolled, neurological disease was observed in 194 (46.5%) and a new AIDS-defining neurological event developed in 23.7% of individuals. Toxoplasmosis (42.3%), cryptococcosis meningitis (12.9%) and tuberculosis (10.8%) were the most common causes of neurological complications. The majority (79.3%) of patients were on highly active antiretroviral treatment and these individuals using HAART showed higher CD4 cell counts (p = 0.014) and presented stable neurological disease (p= 0.0001), although no difference was found with respect to the profile of neurological complications. The neurological diseases continue to be a frequent complication of HIV/AIDS and infections are still its main causes in Brazil, even in the highly active antiretroviral treatment era.

The epidemiology of HIV and AIDS among Central American, South American, and Caribbean immigrants to Houston, Texas

A retrospective study with respect to demographics and clinical parameters was conducted of all HIV/AIDS patients born in Central America, South America, and the Caribbean region, presenting to the Harris County Hospital District (public facilities) between 1994 and 1998. The original case definition criteria were fulfilled by 240 patients, 168 (70.0%) of whom were from Central America (including Panama), 42 (17.5%) of whom were from the Caribbean, and 30 (12.5%) of whom were from South America. The Central America group contained the highest proportion of women (37.5% compared with 20.8% among the group from the Caribbean and South America, P = 0.01, chi-square). The mean age was significantly lower among those born in Central America (32.4 vs. 38.8 for those born in the other two areas). The most commonly observed opportunistic infections were toxoplasmosis (14.8%), pneumocystosis (19.9%), and tuberculosis (12.1%). These data confirm the distinct epidemiologic parameters among Central American residents compared to the non-Central American populations as the Central American patients present with HIV infection to our health care system at a younger age and are more often women. The high rate of toxoplasmosis, pneumocystosis, and tuberculosis among those immigrants from the areas assessed in this study are a reminder of the need for intensified prophylaxis against these infections when working with patients from these populations.

Highly active antiretroviral therapy access and neurological complications of human immunodeficiency virus infection: Impact versus resources in Brazil

Currently, there are almost 600,000 human immunodeficiency virus (HIV)-infected individuals in Brazil. From 1984 to 2004, 362,364 acquired immunodeficiency virus (AIDS) cases were officially reported and 155,000 patients are under highly active antiretroviral therapy (HAART) treatment. Like in developed countries, universal access to treatment in Brazil has definitively changed both mortality and morbidity of AIDS. Today, the median survival time is 58 months, with a 2-year survival of 63%, versus 18 months before HAART. As expected, the incidence of nervous system opportunistic infectious diseases and tumors has also decreased in Brazil. However, few Brazilian reports about neurological manifestations of HIV infection are available, particularly after the beginning of more effective antiretroviral therapy. Autopsy series report that toxoplasmosis is the most prevalent neurological disease, followed by cryptococcosis and HIV encephalitis. A much lower incidence of progressive multifocal leukoencephalopathy has been described in Brazil than in reports from developed countries. A possibility for this discrepancy could be differences in terms of JC virus (JCV) isolates or even the interactions between JCV and local HIV strains. Some particularities about the involvement of the nervous system in Brazilian patients are worthy of note, such as the occurrence of central nervous system involvement in chronic Chagas' disease in patients with AIDS, and the concomitance of leprosy and HIV infection. National surveillance of neurological manifestations of HIV infection is needed to ascertain the real impact of HAART on nervous system diseases associated with AIDS in Brazil.

CD4+ T-cell reconstitution reduces cytomegalovirus in the immunocompromised brain

Cytomegalovirus (CMV) infection is the most common opportunistic infection of the central nervous system in patients with human immunodeficiency virus or AIDS or on immunosuppressive drug therapy. Despite medical management, infection may be refractory to treatment and continues to cause significant morbidity and mortality. We investigated adoptive transfer as an approach to treat and prevent neurotropic CMV infection in an adult immunodeficient mouse model. SCID mice were challenged with intracranial murine CMV (MCMV) and reconstituted with MCMV- or vesicular stomatitis virus (VSV)-sensitized splenocytes, T cells, or T-cell subsets. T cells labeled with vital dye or that constitutively generated green fluorescent protein (GFP) were identified in the brain as early as 3 days following peripheral transfer. Regardless of specificity, activated T cells localized to regions of the brain containing CMV, however, only those specific for CMV were effective at clearing virus. Reconstitution with unsorted MCMV-immune splenocytes, enriched T-cell fractions, or CD4(+) cells significantly reduced virus levels in the brain within 7 days and also prevented clinical disease, in significant contrast with mice given VSV-immune unsorted splenocytes, MCMV-immune CD8(+) T cells, and SCID control mice. Results suggest CMV-immune T cells (particularly CD4(+)) rapidly cross the blood-brain barrier, congregate at sites of specific CMV infection, and functionally eliminate acute CMV within the brain. In addition, when CMV-immune splenocytes were administered prior to a peripheral CMV challenge, CMV entry into the immunocompromised brain was prevented. Systemic adoptive transfer may be a rapid and effective approach to preventing CMV entrance into the brain and for reducing neurotropic infection.

Cytomegalovirus induces T-cell independent apoptosis in brain during immunodeficiency

BACKGROUND

Cytomegalovirus (CMV) is the most common opportunistic viral pathogen associated with HIV/AIDS or immunosuppressive therapy. Systemic pathology may be caused either through direct virus-mediated infection or by indirect mechanisms such as 'by-stander' apoptosis. CMV infection of the central nervous system (CNS) occurs late in disease progression and understanding of pathology in the brain is fundamental for selection of appropriate therapies.

OBJECTIVES

Using a model of disseminated neurotropic CMV disease, these experiments are designed to identify cellular predilection of murine CMV (MCMV) within mature brain and to determine, if CMV induces apoptosis within CNS cells.

STUDY DESIGN

Adult immunodeficient (SCID) and normal BALB/c mice were infected via the tail vein with 4.5 x 10(5)pfu recombinant MCMV expressing a green fluorescent protein reporter. Animals were perfused at various time periods from 3 to 35 days post inoculation and tissues were stained for MCMV, GFAP, NEU-N, MBP, TUNEL, and caspase-3.

RESULTS

CMV infection within brain was observed in multiple, independent foci affecting several different cell types, including neurons, glial cells, meninges, ependymal cells, and cerebral vessels. Cellular changes included nuclear karyopyknosis and karyorrhexis, and associated meningitis, choroiditis, encephalitis, vasculitis, and necrosis. TUNEL and caspase-3 staining of brain-demonstrated apoptosis of nearby 'by-stander' meningial, glial, and neuronal cells, but only in immunodeficient mice lacking T- and B-lymphocytes. Generally, only large CMV infection foci were associated with apoptosis of non-infected adjacent cells.

CONCLUSIONS

These results indicate that MCMV may cause both direct and indirect pathology to brain and that T-cell independent apoptosis of surrounding cells of the CNS may be an important mechanism of disease in the pathogenesis of neurotropic CMV.

Systemic immune deficiency necessary for cytomegalovirus invasion of the mature brain

Cytomegalovirus (CMV) is a significant opportunistic pathogen associated with AIDS and immunosuppressive therapy. Infection of the mature central nervous system (CNS) can cause significant pathology with associated neurological deficits, mental disorders, and cognitive impairment and may have potentially fatal consequences. Using genetically immunocompromised mice, we studied mechanisms of CMV invasion into, and behavior within, the CNS. Adult immunodeficient (nude and SCID) and control mice were peripherally infected with recombinant mouse CMV expressing a green fluorescent protein reporter gene. Control mice actively eliminated acute peripheral infection and were resistant to invasion of CMV into the brain. In contrast, virus infected brains of immunodeficient mice but only after a minimum of 21 days postinoculation. After inoculation, CMV was found in circulating leukocytes (MAC-3/CD45(+)) and in leukocytes within the brain, suggesting these cells as a possible source of CMV entry into the CNS. CNS infection was observed in many different cell types, including neurons, glial cells, meninges, ependymal cells, and cells of cerebral vessels. Infection foci progressively expanded locally to adjacent cells, resulting in meningitis, choroiditis, encephalitis, vasculitis, and necrosis; clear indication of axonal transport of CMV was not found. Regional distribution of CMV was unique in each brain, consisting of randomly distributed, unilateral foci. Testing whether CMV gained access to brain through nonspecific vascular disruption, vascular injections of a tracer molecule revealed no obvious disruption of the blood brain barrier in mice with CMV in the brain. Results indicate the importance of host adaptive immunity (particularly T cells) in controlling entry and dissemination of CMV into the brain and are consistent with the view that virus may be carried into the brain by circulating mononuclear cells that traffic through the blood brain barrier.

Concomitant progressive multifocal leucoencephalopathy and primary central nervous system lymphoma expressing JC virus oncogenic protein, large T antigen

This report describes the concomitant occurrence of the JC virus (JCV) induced demyelinating disease progressive multifocal leucoencephalopathy (PML) and a primary central nervous system lymphoma (PCNS-L) in a patient with AIDS. Postmortem neuropathological examination revealed characteristic features of PML including multiple lesions of demyelination, enlarged oligodendrocytes with hyperchromatic nuclei (many containing eosinophilic intranuclear inclusions), and enlarged astrocytes with bizarre hyperchromatic nuclei. Immunohistochemical analysis demonstrated the expression of the JCV capsid protein VP-1 in the nuclei of infected oligodendrocytes and astrocytes. The PCNS-L lesion located in the basal ganglia was highly cellular, distributed perivascularly, and consisted of large atypical plasmacytoid lymphocytes. Immunohistochemical examination of this neoplasm identified it to be of B cell origin. Moreover, expression of the JCV oncogenic protein, T antigen, was detected in the nuclei of the neoplastic lymphocytes. This study provides the first evidence for a possible association between JCV and PCNS-L.

Predicted amino acid sequences for 100 JCV strains

DNA sequence variation between JCV genotypes is confined largely to noncoding intergenic regions and introns. Nevertheless, evidence suggests that the amino acid sequence variations among the 8 genotypes of JCV can influence the potential for neurovirulence of the virus. In the current study, the amino acid sequences for 100 JCV genomes were translated and grouped into genotype families. Subtype consensus sequences were determined and the type-specific amino acid sequence variants were identified.

Cerebral infarction in adult AIDS patients: observations from the Edinburgh HIV Autopsy Cohort

BACKGROUND AND PURPOSE

Autopsy series of patients with AIDS have found a 4% to 29% prevalence of cerebral infarction. Little is known of the prevalence of cerebral infarction when not associated with non-HIV central nervous system (CNS) infection, lymphoma, or cardioembolic sources. Clinical correlation has seldom been available. We describe the pathological and clinical features of patients from the Edinburgh HIV Cohort Study found to have had cerebral infarcts without evidence of non-HIV CNS infection, CNS lymphoma, or cardioembolic sources at autopsy.

METHODS

From 183 autopsy cases, 26 without evidence of opportunistic cerebral infection or lymphoma were selected. These 26 cases went through a second selection process in which the presence of cerebral infarction, in the absence of the conditions mentioned, was verified. Histology and clinical records for the remaining patients were reviewed.

RESULTS

Ten (5.5%) cases fulfilled the inclusion criteria and demonstrated similar hypoxic-ischemic lesions. Small-vessel thickening was seen in all cases, and perivascular space dilatation, rarefaction, and pigment deposition, with vessel wall mineralization and perivascular inflammatory cell infiltrates, were seen in some cases. Vasculitis was not found. One patient had had a transient ischemic attack, and no patient had had a stroke.

CONCLUSIONS

Cerebral infarcts in HIV-infected patients are not common in the absence of cerebral non-HIV infection, lymphoma, or embolic sources. We found an HIV-associated vasculopathy with similar features in all risk groups. In AIDS patients presenting with stroke or transient ischemic attack, potentially treatable causes, such as cerebral coinfection or tumor, should be sought.

Toxoplasma encephalitis in AIDS patients in São Paulo during 1988 and 1991. A comparative retrospective analysis

We conducted a retrospective analysis of Toxoplasma encephalitis patients from Instituto de Infectologia Emílio Ribas, the main AIDS hospital of São Paulo, Brazil, during two different stages of the HIV epidemics, in 1988 (38 patients) and 1991 (33 patients). There were AIDS-related demographic differences, but the clinical presentation and diagnostic efficiency were similar, usually based on tomography and clinical response to therapy, with a clear distinction from other CNS infections, based on clinical and laboratory findings. Specific serologic studies were performed less often in 1991, with a high frequency of therapy change. The direct acute death rate from Toxoplasma encephalitis was high during both periods, i.e. 8/38 in 1988 and 10/33 in 1991. The direct acute death rate for the patients from the two periods as a whole was 25.4% (18/71), related to the time of HIV infection, absence of fever and presence of meningeal irritation at presentation, blood leukocytes higher than 10,000/mm3 and blood lymphocytes lower than 350/mm3. Toxoplasma encephalitis is a preventable disease when adequate prophylactic therapy is used and is relatively easy to treat in diagnosed HIV patients. Unfortunately, this severe and deadly disorder is the HIV diagnostic disease in several patients, and our data support the need for careful management of these patients, especially in those countries with a high toxoplasmosis prevalence where AIDS is concurrent with economic and public health problems.

Cytomegalovirus cell tropism, replication, and gene transfer in brain

Cytomegalovirus (CMV) infects a majority of adult humans. During early development and in the immunocompromised adult, CMV causes neurological deficits. We used recombinant murine cytomegalovirus (mCMV) expressing either green fluorescent protein (GFP) or beta-galactosidase under control of human elongation factor 1 promoter or CMV immediate early-1 promoter as reporter genes for infected brain cells. In vivo and in vitro studies revealed that neurons and glial cells supported strong reporter gene expression after CMV exposure. Brain cultures selectively enriched in either glia or neurons supported viral replication, leading to process degeneration and cell death within 2 d of viral exposure. In addition, endothelial cells, tanycytes, radial glia, ependymal cells, microglia, and cells from the meninges and choroid were infected. Although mCMV showed no absolute brain cell preference, relative cell preferences were detected. Radial glia cells play an important role in guiding migrating neurons; these were viral targets in the developing brain, suggesting that cortical problems including microgyria that are a consequence of CMV may be caused by compromised radial glia. Although CMV is a species-specific virus, recombinant mCMV entered and expressed reporter genes in both rat and human brain cells, suggesting that mCMV might serve as a vector for gene transfer into brain cells of non-murine species. GFP expression was sufficiently strong that long axons, dendrites, and their associated spines were readily detected in both living and fixed tissue, indicating that mCMV reporter gene constructs may be useful for labeling neurons and their pathways.

Progressive multifocal leukoencephalopathy and JC virus genotypes in West African patients with acquired immunodeficiency syndrome: a pathologic and DNA sequence analysis of 4 cases

OBJECTIVE

Progressive multifocal leukoencephalopathy is caused by polyomavirus JC in immunosuppressed patients. JC virus genotypes are identified by sequence analysis of the viral genome. Despite the prevalence of acquired immunodeficiency syndrome in sub-Saharan Africa, few cases of progressive multifocal leukoencephalopathy have been reported from this region. Here we describe 4 African cases and provide an analysis of viral genotypes.

METHODS

Immunohistochemical staining by labeled streptavidin-biotin for capsid protein antigen was performed on all cases. Polymerase chain reaction amplification of viral genomic DNA was followed by direct cycle sequencing.

RESULTS

JC virus type 3 was identified in 2 cases, and type 6 was isolated in 1 case. The viral regulatory region from 1 case showed an uncommon rearrangement pattern.

CONCLUSIONS

Progressive multifocal leukoencephalopathy in West African patients with acquired immunodeficiency syndrome is caused by African genotypes of JC virus (types 3 and 6). The prevalence of disease in this autopsy series from sub-Saharan Africa (1.5%) was less than has been reported from Europe and the United States (4% to 10%) and may be partly due to biological differences in JC virus genotypes. Further studies will be needed to confirm this observation.

Molecular epidemiology of human polyomavirus JC in the Biaka Pygmies and Bantu of Central Africa

Polyomavirus JC (JCV) is ubiquitous in humans and causes a chronic demyelinating disease of the central nervous system, progressive multifocal leukoencephalopathy which is common in AIDS. JCV is excreted in urine of 30-70% of adults worldwide. Based on sequence analysis of JCV complete genomes or fragments thereof, JCV can be classified into geographically derived genotypes. Types 1 and 2 are of European and Asian origin respectively while Types 3 and 6 are African in origin. Type 4, a possible recombinant of European and African genotypes (1 and 3) is common in the USA. To delineate the JCV genotypes in an aboriginal African population, random urine samples were collected from the Biaka Pygmies and Bantu from the Central African Republic. There were 43 males and 25 females aged 4-55 years, with an average age of 26 years. After PCR amplification of JCV in urine, products were directly cycle sequenced. Five of 23 Pygmy adults (22%) and four of 20 Bantu adults (20%) were positive for JC viruria. DNA sequence analysis revealed JCV Type 3 (two), Type 6 (two) and one Type 1 variant in Biaka Pygmies. All the Bantu strains were Type 6. Type 3 and 6 strains of JCV are the predominant strains in central Africa. The presence of multiple subtypes of JCV in Biaka Pygmies may be a result of extensive interactions of Pygmies with their African tribal neighbors during their itinerant movements in the equatorial forest.

Profile of central nervous system pathology in patients with AIDS: an autopsy study from India

OBJECTIVE

To study the spectrum of neuropathological brain lesions in HIV/AIDS cases.

DESIGN

Retrospective autopsy study between 1988 and mid-1996 at a tertiary level public hospital.

METHODS

Eighty-five adult brains, with at least 21 sections from each, were examined using routine and special stains.

RESULTS

Risk factors in 64 men (75%) and 21 women (25%) included heterosexual contact with multiple sexual partners (83 cases, 98%), homosexual behaviour (one case, 1%) and blood transfusion (one case, 1%). Central nervous system (CNS) lesions were observed in 67 cases (79%). Opportunistic infections were present in 33 cases (39%), which included toxoplasmosis (11 cases, 13%), tuberculosis (10 cases, 12%), cryptococcosis (seven cases, 8%), and cytomegalovirus infection (six cases, 7%). Multifocal myelin loss was observed in 18 cases (21%), microglial nodules in 15 cases (18%), and angiocentric pallor in five cases (6%). Infarcts/haemorrhages were present in 13 cases (15%), choroid plexitis in 21 cases (25%), lymphocytic meningitis without opportunistic infection in 21 cases (25%), and calcification in four cases (5%). A dual infectious pathology was observed in one case (1%). Multinucleated giant cells and primary CNS lymphoma were not found in any of our cases.

CONCLUSIONS

Patient profile and risk factors for AIDS in India differ from those reported in industrialized countries. Although not reported from India in the pre-AIDS era, toxoplasmosis was the most frequently observed CNS opportunistic infection in our study. CNS tuberculosis is frequently observed in Indian AIDS cases compared with reports from industrialized countries where its occurrence is uncommon. Death due to systemic opportunistic infections may punctuate the course of HIV encephalitis and prevent its full-blown morphological expression.

Progressive multifocal leukoencephalopathy in a child with acquired immunodeficiency syndrome (AIDS)

Progressive multifocal leukoencephalopathy is a rare viral-induced demyelinating disease associated to immunodeficiency. A 10-year-old boy with AIDS is reported, who developed subacute cerebellar signs and symptoms with multiple cranial nerve involvement and dementia. A computed tomography scan revealed a focal nonenhancing area of low attenuation in the cerebellum. On magnetic resonance imaging high signal lesions in T2 weighted sequences were shown. The biopsy of one of those lesions showed the typical histological findings of progressive multifocal leukoencephalopathy. It seems important to consider this diagnosis in children with AIDS who present with progressive neurological features.

Fungal infections

Fungal infections have increased in frequency in the last decades because of the growing number of immunocompromised patients who survive longer periods of time than in the past, the widespread use of immunosuppressive drugs, a large aging population with increased numbers of malignancies, and the spread of AIDS. Although fungi are present everywhere, some mycoses predominate in the tropics, not only in view of warm temperature and humid climate, which favor their growth, but also because of inadequate hygienic and working conditions brought about by poverty. Mycotic diseases in the brain are usually secondary to infections elsewhere in the body, usually the lungs, less often from other extracranial sites, and in the vast majority of the cases spread via blood circulation. Only occasionally they result from direct extensions from infections of the sinuses or bone, and less frequently from prosthetic heart valves. Candida may be endogenous in origin, inhabiting the digestive tract. Most fungi cause basal meningitis or intraparenchymal abscesses. Direct extension from the cribriform plate cause necro-hemorrhagic lesions in the base of the frontal lobe. Although fungi are common in our environment, few are pathogenic. In this paper mycotic infections are divided into opportunistic and pathogenic; although most of the latter have also been described in immunosuppressed patients, some of those caused by opportunistic organisms, have also occurred in the absence of predisposing factors.

Cytomegalovirus infection of the brain in AIDS: a clinicopathological study

Based on neuropathological findings, a retrospective case control study of 39 patients with acquired immune deficiency syndrome (AIDS) and confirmed cytomegalovirus (CMV) infection of the brain is presented. Since 1989, the incidence has increased progressively and, in 1994, CMV was the most frequent opportunistic central nervous system (CNS) infection. Of the patients with CMV infections of the brain 16 had one or more coexisting secondary opportunistic and/or tumorous lesions in the CNS. Cerebral involvement by CMV was more frequent in patients with multiple extracerebral organ infections, while 7 among the 39 reported cases showed isolated CMV infection of the brain. The evaluation of the clinical records of 21 patients revealed neuropsychiatric signs and symptoms in 10, while these were absent in 11. All of these patients revealed various types of cerebral lesions related to CMV infection: ventriculitis, focal lesions, and microglial nodule encephalitis. The extent and distribution of cerebral lesions showed no significant correlations with clinical, radiological, or laboratory findings. Further clinicopathological studies are warranted to recognize CMV infections of the CNS and to allow earlier and more efficient treatment of this rather frequent complication of AIDS.

[Clarithromycin combined with pyrimethamine in cerebral toxoplasmosis--a report of 2 cases]

The authors report the use and the outcome of claritromycin associated with pyrimethamine in the treatment of toxoplasma encephalites in two patients with AIDS. Both patients had the diagnosis stablished on clinical grounds, positive sorology (IgG) for toxoplasmosis and computed-tomographic (CT) scan of the brain showing lesions consistent with T. gondii encephalitis. The two patients were initially treated with pyrimethamine and sulfadiazine, which was changed to clindamycin due to allergic reactions. These reactions (skin rash) occurred with clindamycin as well and the patients were treated with claritromycin and pyrimethamine. The scheduled regimens were 1.5 to 2 g of clarithromycin plus 25 mg of pyrimethamine. The clinical response was very good in both cases with regression of neurologic signs and encephalitic abnormalities observed on CT scan. The authors suggest that clarithromycin associated with pyrimethamine may be an alternative treatment for toxoplasmosis in AIDS patients, who cannot receive or tolerate sulfa treatment.

The neuropathology and epidemiology of AIDS. A Berlin experience. A review of 200 cases

The brains of 200 patients who died with Acquired Immunodeficiency Syndrome (AIDS) from Berlin were examined retrospectively. This study was specifically intended to evaluate and document the prevalence of neuropathologic abnormalities, establishing the frequency of the various types of structural lesions, their combinations, their relative incidence, and the risk factors involved in different age groups. The data were compared and contrasted with the findings reported from other parts of the world and other German cities. It was found that the mean age of this group of patients was 41.4 years old, 75% were homosexual/bisexuals (H/B) and 18.5% were drug abusers (DA). Only 5.5% were women. Brain parenchymal changes, called in this report, HIV-related encephalopathy (HIVRE), characterized by vacuolization or spongy changes and astrocytosis in the subcortical white matter, and occasionally in gray matter, were found in 67 patients (33.5%). Drug abusers had a higher incidence of HIVRE (59.5%) compared with homosexual/bisexuals (28%). This is statistically significant (p < 0.0005). CMV encephalitis was found in 26 patients (13%) (8% of the drug abusers in contrast to 13% in the homosexual/bisexuals group). Primary central nervous system lymphoma (PCNSL) was seen in 28 patients (14%) regardless of the risk factor involved. 20 (13%) of the 150 H/B and 3 (8%) of the 37 DA had CMV encephalitis. Of the 150 H/B, 24 (16%) had PCNSL compared with only 4 of 37 (11%) of the DA. A significant incidence of opportunistic infections, both protozoal and viral was found in all groups. Cerebral toxoplasmosis occurred in 68 patients (34%). Microglial (phagocytic) nodules, probably related to CMV or cerebral Toxoplasmosis, were observed in 40 cases (20%). Diffuse microglial proliferation was noted in 104 patients (52%). Cerebral cryptococcosis was found in three patients. Progressive multifocal leukoencephalopathy was seen in 16 patients (8%). Various combinations of CNS pathological processes were found in 44 of the patients (22%). These include concomitant infections with Toxoplasma gondii and HIVRE in 13 patients; Toxoplasmosis and PCNSL in 8 patients; Toxoplasmosis with CMV and HIVRE in 4 patients; Toxoplasmosis with CMV in 2 patients; Toxoplasmosis with PCNSL and CMV in 2 patients; Toxoplasmosis with PCNSL and HIVRE in 2 patients and Toxoplasmosis with PML and HIVRE in 2 patients; Cerebral CMV with PCNSL and HIVRE in 4 patients; Cerebral CMV with HIVRE in 2 patients; PML with PCNSL in one patient; PML with HIVRE in 2 patients; and PML with PCNSL and HIVRE in one patient. Cerebrovascular lesions were found in 34 patients (17%).(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of Strongyloides stercoralis in the cerebrospinal fluid of a patient with acquired immunodeficiency syndrome

We report a case of Strongyloides stercoralis hyperinfection syndrome in a patient with acquired immunodeficiency syndrome with CNS involvement who died despite prompt institution of thiabendazole.

Experience with brain biopsy in acquired immune deficiency syndrome-related focal lesions of the central nervous system

Involvement of the central nervous system (CNS) in patients with acquired immune deficiency syndrome (AIDS) is an increasing clinical problem. The most common brain complications are toxoplasmosis (50-70 per cent), primary CNS lymphoma (20-30 per cent) and progressive multifocal leucoencephalopathy (10-20 per cent). Almost two-thirds of these conditions can be treated, early diagnosis and therapy leading to survival with a good quality of life. Although clinical and neuroradiological criteria alone may have high predictive value, they are not sufficient to distinguish the broad spectrum of diseases reliably. Consequently, biopsy appears necessary for definite diagnosis in some cases. The potential role and timing of brain biopsy have been assessed. Twenty-four of 50 human immunodeficiency virus-seropositive patients with focal cerebral lesions were considered for biopsy between October 1991 and December 1992. Twelve underwent brain biopsy, seven stereotactic and five ultrasonographically guided. A diagnosis was achieved in 11 patients: six primary lymphoma, three progressive multifocal leucoencephalopathy, and one mycotic and one tuberculous abscess. Both techniques proved to be safe and reliable, with a 92 per cent diagnostic rate. These data confirm the usefulness of biopsy in patients with AIDS with its wide range of associated cerebral lesions that require different aggressive treatments. On the basis of this preliminary experience and reports in the literature, it is considered that brain biopsy is indicated for patients with focal enhancing cerebral mass lesions seen on computed tomography and magnetic resonance imaging who do not respond to an appropriate trial of empirical antitoxoplasmosis therapy and for those showing rapid clinical deterioration in whom imaging and serology do not suggest toxoplasmosis.

[The neuropathology of the acquired immunodeficiency syndrome (AIDS)]

The nervous system is frequently involved in patients with AIDS. The lesions can be due to the human immunodeficiency virus (HIV), to opportunistic agents, to the development of tumours, and to occasional nonspecific factors, such as circulatory, metabolic and degenerative changes. The changes directly related to the presence of the HIV include the HIV encephalitis and leucoencephalopathy, the diffuse polydystrophy and the vacuolar myelopathy. The pathogenesis of these lesions is not yet completely clear. Macrophages are the main cells infected by the HIV, and it seems that the cytotoxic effects on the nervous tissue are indirect, may be due to the release of substances by infected macrophages. Among the opportunistic infections, the most frequent is toxoplasmosis followed by cryptococcosis and cytomegalovirus infection, with some differences in series from various countries. Many other agents have been observed in the brain of patients with AIDS. B-cell lymphoma is the most frequent tumour found in the brain and it is not uncommon the association of infections and/or tumours.