Plasma CXCL10 correlates with HAND in HIV-infected women.

HIV-associated neurocognitive disorder (HAND) is characterized by chronic immune activation. We aimed to identify biomarkers associated with HAND and to investigate their association with cognitive function and sex, in a homogenous cohort of HIV-infected (HIV+) young adults, parenterally infected during early childhood. One hundred forty-four HIV+ Romanian participants (51% women) without major confounders underwent standardized neurocognitive and medical evaluation in a cross-sectional study. IFN-γ, IL-1ß, IL-6, CCL2, CXCL8, CXCL10, and TNF-α were measured in plasma in all participants and in cerebrospinal fluid (CSF) in a subgroup of 56 study participants. Biomarkers were compared with neurocognitive outcomes, and the influence of sex and HIV disease biomarkers was assessed. In this cohort of young adults (median age of 24 years), the rate of neurocognitive impairment (NCI) was 36.1%. Median current CD4+ count was 479 cells/mm3 and 36.8% had detectable plasma viral load. Women had better HIV-associated overall status. In plasma, controlling for sex, higher levels of IL-6 and TNF-α were associated with NCI (p < 0.05). Plasma CXCL10 showed a significant interaction with sex (p = 0.02); higher values were associated with NCI in women only (p = 0.02). Individuals with undetectable viral load had significantly lower plasma CXCL10 (p < 0.001) and CCL2 (p = 0.02) levels, and CSF CXCL10 (p = 0.01), IL-6 (p = 0.04), and TNF-α (p = 0.04) levels. NCI in young men and women living with HIV was associated with higher IL-6 and TNF-α in plasma, but not in the CSF. CXCL10 was identified as a biomarker of NCI specifically in women with chronic HIV infection.

Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection.

We evaluated the impact of latent toxoplasmosis (LT) on neurocognitive (NC) and neurobehavioural functioning in young adults with and without chronic HIV infection, using a standardised NC test battery, self-reported Beck Depression Inventory, Frontal System Behavior Scale, MINI-International Neuropsychiatric Interview and risk-assessment battery. 194 young adults (median age 24years, 48.2% males) with chronic HIV infection (HIV+) since childhood and 51 HIV seronegative (HIV-) participants were included. HIV+ individuals had good current immunological status (median CD4: 479 cells/µl) despite a low CD4 nadir (median: 93 cells/µl). LT (positive anti-Toxoplasma IgG antibodies) was present in one third of participants. The impairment rates in the HIV- with and without Toxo were not significantly different (p=0.17). However, we observed an increasing trend (p<0.001) in impairment rates with HIV and LT status: HIV-/LT- (6.1%); HIV-/LT+ (22%), HIV+/LT- (31%), HIV+/LT+ (49%). In a multivariable analysis using the entire study group there were main effects on cognition for HIV and also for LT. Within the HIV+ group LT was associated with worse performance globally (p=0.006), in memory (p=0.009), speed of information processing (p=0.01), verbal (p=0.02) and learning (p=0.02) domains. LT was not associated with depressive symptoms, frontal systems dysfunction or risk behaviors in any of the groups. HIV participants with lower Toxoplasma antibody concentration had worse NC performance, with higher GDS values (p=0.03) and worse learning (p=0.002), memory (p=0.006), speed of information processing (p=0.01) T scores. Latent Toxoplasmosis may contribute to NC impairment in young adults, including those with and without chronic HIV infection.

How much do antiretroviral drugs penetrate into the central nervous system?

The central nervous system can act as a compartment in which HIV can replicate independently from plasma, and also as a sanctuary in which, under suboptimal drug pressure, HIV antiretroviral genetic variants can occur. Continuous replication of HIV in brain can contribute to neurocognitive impairment. Therefore, reaching adequate concentrations of antiretrovirals in the central nervous system might be essential in providing neuroprotection and improving neurocognition. Antiretrovirals have a restricted entry into the brain, due to several factors: the unique structure of the blood-brain barrier, and the existence of efficient efflux mechanisms. However, there is a high variability of antiretrovirals in reaching therapeutic drug concentrations in cerebrospinal fluid, that depend on the characteristics of the antiretrovirals (molecular weight, lipophilicity, protein binding) and on their capacity to be substrate for efflux transporters. The review aims to discuss the main mechanisms that interfere with antiretroviral penetration into central nervous system, and to summarize the current data concerning the penetrability of different antiretrovirals into the cerebrospinal fluid.

"Trial moves rapidly on, when the judge has determined the sentence beforehand" (W. Scott: Ivanhoe, 36) or pitfalls in serosurvey of anti-hepatitis C antibody in children.

Hepatitis C is and will be a major public health concern. Confirmed infections were reported from all Romanian counties but important differences between regions raise several explanations. Differences may reflect the different levels of testing, the performances of laboratories in confirming initially reactive samples or the risk factors higher prevalence. We have suggested that the prevalence of anti HCV infections can be a surrogate marker for the quality of parenteral medical or paramedical interventions. Present report identified additional problems in the surveillance of HCV infection in children. We screened 1787 samples from children hosted in orphanages (children under three years old) or in preschool children institutions (between 3-7 years old). We detected 31 repeatedly reactive samples with two EIA screening kits but confirmed only 8 in WB anti HCV. Four confirmed samples come from children under four months old suggesting maternally transmitted antibodies. In highly endemic area, many infants have maternally derived antibodies and the wane of reactivity comes with age above 12 months. Therefore, the prevalence of anti HCV antibody in infants reflects the prevalence in adult population. Confirmatory tests are mandatory for the serosurvey in children. More frequent than adults samples, children EIA reactive samples give indeterminate or negative Western Blot profiles. Only the viral load evaluation can confirm those samples as false positive or, on the contrary, samples at the beginning of seroconversion.

Assessment of the anti-hepatitis B vaccination efficacy in high risk children.

In October 1995, The Ministry of Health has initiated the national immunization program of newborns against hepatitis B. Owing to the frequency of asymptomatic Hepatitis B clinical forms in children, as well as the deficiencies in the surveillance system, the assessment of the vaccination efficacy can be performed objectively only by the detection of the prevalence of anti HBs antibodies in children to whom the complete three doses of immunization schedule have been administered (at 0, 2 and 6 months of age). We report in this study the results of a seroprevalence research carried out on a group of 272 children from orphanages who have been vaccinated. A protective anti HBs titer (> 10 mIU) was recorded only in 66.3% of cases; other 10 samples contained antibodies at a titer lower than the protective level. In the 80 children without seroconversion the presence of anti HBc antibodies (marker for the natural infection) was investigated. 30% of the seronegative children have anti HBc antibodies from which 54.2% have also HbsAg. Significant differences were recorded in the seroconversion level and in the geometric mean of titers between the various units in which sera were collected. In four orphanages (district Arad, Jassy, Sibiu and Teleorman) the seroconversion exceeded 90%, in 5 orphanages it was over 80% and in the others it ranged from 30% to 70%. The lowest seroconversions were recorded in the orphanages in Bucharest, Botosani, Galati and Olt. The possible causes of the low immunogenicity are analyzed: non-vaccination or incomplete vaccination; low immunoreactivity of children, many of whom are premature; high HbsAg carriage rate among the mother's etc. Although the evolution of the post vaccinal seroconversion is not a routine practice in the appraisement of Hepatitis B vaccine immunogenicity, our results require the extension of the study in order to adopt the most effective vaccinal strategy.

Cerebrospinal fluid western Blot profiles in the evolution of HIV-1 pediatric encephalopathy.

In order to obtain information on neurologic AIDS, 54 white caucasian children infected by nosocomial route with a median age of 46.2 +/- 7 months were followed up prospectively for a median of 12 months with three months Denver tests neurologic evaluation and six months serologic investigations in CSF and sera. Paired CSF and serum samples, collected on the same day, from children with AIDS encephalopathy, were analysed for the permeability of the blood brain barrier (BBB) and for intrathecal production of anti HIV specific antibodies. A prospective follow-up and repeated comparison of WB profiles and the presence of anti V3 antibodies in CSF and sera was done, as well as an evaluation of the modification in the CSF antibody specificity (anti gag Western Blot scoring) with disease progression. An increased intrathecal synthesis of IgG was recorded in all subjects, in spite of an unaltered BBB permeability. No significant differences were recorded for the anti gag score in the serum samples, which was stable between 9.1-10.4. By contrast, the score for CSF samples decreases significantly with disease progression, from 8.7 in children without encephalopathy, to 6.5 in those with stationary disease and 3.6 in the progressive encephalopathy group. A strong correlation was found between the level of anti p24 antibodies determined by ELISA and the anti gag score quantified by WB for the same CSF samples. The p24 antigen was found to be positive only in 3 cases, even after immune complex dissociation. Anti V3 antibodies were not detected in CSF samples from patients with functional BBB. The decline in anti-gag antibody reactivity in CSF is an early indicator of disease progression, reflecting a severe course of neurological impairments. The absence of anti V3 antibodies in the CSF samples suggests that the PND of neurotropic strains mapped in distinct positions into the V3 loop. These results reflect the selection of antigenic escape mutants which evolve in the CNS, distinct from the blood lymphotropic isolates.

A high number of severe neurologic clinical forms during an epidemic of West Nile virus infection.

The serologic confirmation of more than 800 cases hospitalized during the viral meningoencephalitis epidemic caused by the West Nile virus (WNV) that affected the South-East of Romania during the summer of 1996 consolidated the case definition in over 80% of the patients admitted to the hospital with neurological impairments. Other clinical forms of the WN infection were reported only scarcely during the epidemic and were seroconfirmed at a lower rate (60%). IgM capture ELISA (MAC-ELISA) is a test of choice for the rapid diagnosis. The major advantage of MAC-ELISA procedure is the high probability of accurate diagnosis of WN infection when the test is performed only with acute serum or cerebrospinal fluid (CSF) specimens obtained while the patient is still hospitalized. Rapid diagnosis by MAC-ELISA is important for the institution of public health control, but the results obtained have also some predictive values. We report the serological patterns of 65 pairs of CSF and serum samples collected in the early days of neuroinfection for diagnostic purposes. An unexpected onset of the intrathecal specific humoral immune response before serum immunoglobulins synthesis was recorded in 25% of cases. For 14 patients with intrathecal onset of IgM synthesis, their records evaluated retrospectively showed a severe evolution. The presence of only IgM antibodies in CSF is a characteristic which matched with other laboratory variables described which predict poor evolution in viral encephalitis: pleocytosis, elevated protein concentration in CSF (> 100 mg per deciliter), hyponatremia (< 130 mmol per liter).

Syncytium forming capacity of HIV 1 strains in inhibited by pretreatment of CD4 expressing cells with 3'-azido-3'-deoxythymidine but not by alpha interferon.

3'azido-3'deoxythymidine (AZT) inhibits the ability of uninfected CD4 expressing cells to participate in syncytium formation, when cocultured with cells chronically infected with human immunodeficiency virus type 1 (HIV 1). The inhibition of giant cells formation is similar, irrespective of the AZT-sensitive or resistant phenotype of the HIV1 strains. The effect on syncytium formation occurs when the uninfected target cells are pretreated with AZT, the therapeutic index varying between 290 (CEMss, H9 and > 2000 (HeLa CD4 beta gal). The syncytium reducing effect of AZT is an additional antiviral property, distinct from the inhibition of HIV replication. The HIV 1 phenotype (AZT sensitive or resistant) determines differences both in the morphology of syncytia and in the kinetics of syncytium formation. Pretreatment of the target cells with alpha interferon (125-2000 UI/ml) either alone or in combination with AZT, has no effect on the ability of these cells to participate in syncytium formation, probably owing to the basal IFN synthesis in the system.

Considerations about the prophylactic role of T cell vaccination in HIV infection.

The AIDS epidemic in Romania has properties that are both common to countries of Eastern Europe and unique to Romania. The unique aspects include the large number of cases in children infected parenterally and a relatively low but steadily increasing number of HIV infected adults. Other groups of children and adults were also exposed at risk to acquire HIV by transfusion with unscreened blood or by multiple parenteral treatments with potentially contaminated needles. Our hypothesis was that a substantial number of people in area of high endemicity was "silently" infected but did not undergo specific immune response or clinical signs. In an attempt to explore the possibility that immunization with autologous proteins (consequence of multiple transfusions) can play a role in the protection from HIV infection or in slowing down the progression of disease, we compared the incidence of autoantibodies (anti-nuclear, smooth muscle and anti-HEp-2) in a group of long survivors children with AIDS, in HIV infected children with rapid evolution and in adults at risk for parenteral acquisition of blood borne viral disease. We analyzed also the incidence of some blood borne viral infections and the presence of anti-HLA antibodies in the same groups of patients. Our results do not support the suggestion that HIV infection or AIDS can be prevented, respectively, delayed by T-cell vaccination.

[Human herpesvirus 6. General overview]. / Le virus herpétique humain du type 6. Présentation générale.

Human herpesvirus 6 (HHV6) was first isolated in 1985 and included in the Herpesviridae family and the beta-herpes virinae subfamily, mainly due to its genomic similarities to the human cytomegalic virus (HCMV). HHV6 is largely disseminated in the population. The contamination takes place very early, most frequently before the age of three. In some very rare cases, a benign illness is produced, known since 1911 as Roseolum infantum or Exanthemum subitum. Seroepidemiological surveys showed that anti-HHV6 IgG antibodies were present in more than 60% of the adult population. By now, there are good information about in vitro cultivability of the virus, viral genome and proteins, epidemiology of the infection and etiopathogenic relation between virus and Exanthemum subitum. Relations between virus and lymphoproliferative diseases, some auto-immune diseases, chronic fatigue syndrome and some other diseases are less clear. Relation between this virus and HIV-infection is another problem requiring more research.

Neuroophthalmological examination in children with AIDS.

Evaluation of HIV disease status includes physical examination (anthropomorphic measurements, neurological assessment, etc.) and laboratory examination. Consideration should be given to changes from baseline values, age adjusted normal values and the rapidity of changes. Here we compare results of neuroophthalmologic assessment with Western Blo (WB) profiles in cerebrospinal fluids (CSF) of 54 children with AIDS. Children were classified by Denver Developmental Screening Test (DDST) administration in encephalopathy positive (n = 44) and encephalopathy negative (n = 10) groups. Neuroophthalmological examination which included nine items with good test-retest reliability showed that two of them (nystagmus on following and visual memory impairment) appeared early in the encephalopathy free group and correlated with the loss of some gag band in Western Blot (lower gag score). No correlation was however, found with respect to p24 antigen level in cerebrospinal fluid, a marker which reflects CNS viral load.

Preliminary results of HIV screening in sentinel facilities in Romania.

In the first months of 1994, 393 patients (random consecutive clinic attenders) from three sentinel clinics were tested for anti-V3 loop antibodies in ELISA with a branched synthetic peptide reproducing eight copies of full V3 sequence. Compared with a commercial HIV 1/2 ELISA kit the sensitivity of anti-V3 assay was 97.6% and the specificity 89.7%. The seroprevalence in women attending prenatal clinic was 7.54% and in children with multiple hospitalization record, 3.82%. Both heterosexual and parenteral transmission through unsafe medical practices fuel actual AIDS epidemic in Romania.

Relevance of the reactivity of HIV 1 positive sera with synthetic peptides for understanding antigenic differences between circulating strains.

Several problems have arisen concerning the detection methodology of sources and chains of HIV transmission based on molecular and antigenic relatedness of HIV isolates. Great progress in mapping virus genome or provirus, especially in identifying the changes in the env gene provides interesting data for molecular epidemiology. We address the same problem by the investigation of the reactivity of sera from HIV 1 seropositive children with two panels of synthetic peptides mimicking immunoreactive fragment of HIV1 glycoproteins in solid phase EIA. The samples proceed from two distinct settings: an orphanage in which nosocomial transmission was highly suspected and from different hospitals caring for HIV infected children. The synthetic peptides have sequences which reproduce two target regions: one in the principal neutralization domain of gp 120 (V3 loop) and the other at the COOH end of gp 41. Our results indicate that minimal differences in aminoacids flanking central conserved GPGRA region in V3 loop of gp 120 evidence strain specific antibodies while the COOH end of gp 41 reveals antibodies which link HIV 1 strains in a broad fashion. Sera from HIV infected children collected in different settings recognize the same synthetic peptides panel with distinct frequencies suggesting circulation of different antigenic strains.