Structural brain differences in school-aged children who are HIV-exposed uninfected

Background: Antiretroviral therapy (ART) has dramatically reduced perinatal HIV transmission, leading to a growing population of children who are HIV-exposed but uninfected (CHEU). While the neuroanatomic developmental impacts of in utero HIV and ART exposure have been studied in young children, long-term effects on school-aged children are poorly understood, prompting this investigation. Methods: Fifty-eight CHEU and 38 children who are HIV-unexposed, uninfected (CHUU), 6–12 years old, were recruited through hospitals and community groups in Ontario, Canada. From T1-weighted magnetic resonance images, volume, cortical thickness, and gray-/white-matter tissue volume were extracted. Multiple linear regression models controlling for sex, age, household income, and total brain volume were fit to assess differences by in utero HIV exposure, with additional sex-stratified analyses to uncover sex-specific effects. Results: Compared with CHUU, CHEU showed total brain volumes that were significantly smaller by 49.7cm3 (95% CI [− 95.66, − 3.67]) and cortices thinner by 0.08 mm (95% CI [− 0.13, − 0.02]). In male CHEU, three regions displayed volumetric age-exposure interactions: the bilateral pars opercularis at 0.36 cm3/year (95% CI [0.10, 0.62]), left rolandic operculum at 0.22 cm3/year (95% CI [0.04, 0.39]) and left precentral gyrus at 0.71 cm3/year (95% CI [0.22, 1.21]), suggesting delayed maturation in those regions. Bilateral frontal lobe cortical thickness was reduced by 0.07 mm in CHEU (95% CI [− 0.14, − 0.006]), most pronounced in the left orbital middle frontal gyrus with a reduction of 0.20 mm among male CHEU (95% CI [− 0.32, − 0.07]). An age-exposure interaction of 0.06 cm3/year in bilateral amygdala volume (95% CI [− 0.11, − 0.01]) suggested reduced growth or altered developmental trajectory among CHEU, whereas male CHEU showed bilateral hippocampal volumes diminished by 0.21 cm3 (95% CI [− 0.40, − 0.01]). Conclusions: These findings suggest that in utero HIV and ART exposure have broad neuroanatomic developmental impacts, particularly in boys, with significant differences in brain regions critical for motor function, expressive language, memory, and emotion. These structural differences align with previously reported motor and language deficits and highlight the importance of early intervention and tailored support strategies for CHEU

Cynomolgus Macaque as an Animal Model for Severe Acute Respiratory Syndrome

BACKGROUND: The emergence of severe acute respiratory syndrome (SARS) in 2002 and 2003 affected global health and caused major economic disruption. Adequate animal models are required to study the underlying pathogenesis of SARS-associated coronavirus (SARS-CoV) infection and to develop effective vaccines and therapeutics. We report the first findings of measurable clinical disease in nonhuman primates (NHPs) infected with SARS-CoV. METHODS AND FINDINGS: In order to characterize clinically relevant parameters of SARS-CoV infection in NHPs, we infected cynomolgus macaques with SARS-CoV in three groups: Group I was infected in the nares and bronchus, group II in the nares and conjunctiva, and group III intravenously. Nonhuman primates in groups I and II developed mild to moderate symptomatic illness. All NHPs demonstrated evidence of viral replication and developed neutralizing antibodies. Chest radiographs from several animals in groups I and II revealed unifocal or multifocal pneumonia that peaked between days 8 and 10 postinfection. Clinical laboratory tests were not significantly changed. Overall, inoculation by a mucosal route produced more prominent disease than did intravenous inoculation. Half of the group I animals were infected with a recombinant infectious clone SARS-CoV derived from the SARS-CoV Urbani strain. This infectious clone produced disease indistinguishable from wild-type Urbani strain. CONCLUSIONS: SARS-CoV infection of cynomolgus macaques did not reproduce the severe illness seen in the majority of adult human cases of SARS; however, our results suggest similarities to the milder syndrome of SARS-CoV infection characteristically seen in young children

Molecular mechanisms of severe acute respiratory syndrome (SARS)

Severe acute respiratory syndrome (SARS) is a new infectious disease caused by a novel coronavirus that leads to deleterious pulmonary pathological features. Due to its high morbidity and mortality and widespread occurrence, SARS has evolved as an important respiratory disease which may be encountered everywhere in the world. The virus was identified as the causative agent of SARS due to the efforts of a WHO-led laboratory network. The potential mutability of the SARS-CoV genome may lead to new SARS outbreaks and several regions of the viral genomes open reading frames have been identified which may contribute to the severe virulence of the virus. With regard to the pathogenesis of SARS, several mechanisms involving both direct effects on target cells and indirect effects via the immune system may exist. Vaccination would offer the most attractive approach to prevent new epidemics of SARS, but the development of vaccines is difficult due to missing data on the role of immune system-virus interactions and the potential mutability of the virus. Even in a situation of no new infections, SARS remains a major health hazard, as new epidemics may arise. Therefore, further experimental and clinical research is required to control the disease

Quantiferon Gold-in-tube assay for TB screening in HIV infected children: influence of quantitative values

Abstract Background HIV infected children are at increased risk of TB disease and require annual TB screening. Data on use of IGRA for TB screening in them are limited. We retrospectively evaluated the usefulness of Quantiferon Gold-in-tube test (QFT), an IGRA in screening for LTBI in relatively healthy, immunologically stable HIV infected children. Methods HIV infected children with no prior history of TB were screened for latent TB as part of routine care. They underwent risk of TB assessment, TST and QFT. QFT was repeated twice or three times depending on the quantitative values. Independent test validation was also performed. Results Eighty one children had 109 QFT tests. All had adequate mitogen responses. The initial QFT was positive in 15 (18.5%) children; quantitative IGRA responses were 0.35-1.0 IU/mL in 9 (60%), 1.0-10 IU/mL in5 (33.3%) and >10 IU/mL in 1 (6.7%). None that tested positive had documented TB exposure or TB disease. Baseline characteristics in the QFT positive and negative groups were similar. Repeat testing within 17 weeks demonstrated reversion to negative in 79% of cases. Repeat blinded independent testing of all QFT positive results and a random selection of initial negative tests demonstrated concordance in 96% of cases. Seven children (QFT > 1.0 IU/mL or positive TST) were offered INH preventive therapy. In no case has TB disease developed in 2 years of close follow-up. Conclusions QFT is a valid method for LTBI screening relatively healthy, immunologically stable HIV infected children. However, reversion to negative on repeat testing and lack of correlation with TST results and risk of TB exposure makes interpretation difficult