Is low-level HIV-1 viraemia associated with elevated levels of markers of immune activation, coagulation and cardiovascular disease?

OBJECTIVES: The clinical significance of low-level viraemia (LLV) during antiretroviral therapy (ART) is debated. We retrospectively investigated longitudinal levels of plasma markers associated with inflammation, altered coagulation and cardiovascular disease in Swedish HIV-positive adults in relation to LLV or permanent virological suppression during long-term ART. METHODS: Plasma levels of C-reactive protein (CRP), D-dimer, vascular cell adhesion molecule 1 (VCAM-1), suppression of tumorigenicity 2 (ST2), growth differentiation factor 15 (GDF-15), soluble CD14 (sCD14), soluble CD163 (sCD163), interferon-γ-induced protein 10 (IP-10) and ß-2-microglobulin were measured in 34 individuals with LLV (viral load 50-999 HIV-1 RNA copies/mL) and in matched controls with persistent virological suppression. Biomarker levels were analysed in samples obtained during episodes of LLV and follow-up samples obtained 1 year later (with similar timing for controls). All biomarkers were analysed using an independent sample t-test and analysis of covariance (ANCOVA) after logarithmic transformation. Log-rank analysis was applied for markers with concentration values out of range. RESULTS: Compared with controls, patients with LLV had significantly higher levels of GDF-15 [geometric mean 3416 (95% confidence interval (CI) 804-14 516) pg/mL versus 2002 (95% CI 355-11 295) pg/mL in controls; P = 0.026] and D-dimer [mean 1114 (95% CI 125-9917) ng/mL versus 756 (95% CI 157-3626) ng/mL; P = 0.038] after adjustment for age, CD4 count nadir and type of ART. In the unadjusted t-test, only GDF-15 was significantly higher and in the log-rank test, both GDF-15 and D-dimer were significantly elevated. No significant differences were observed for the other biomarkers analysed. CONCLUSIONS: Although levels of inflammation markers were similar in ART recipients with and without LLV, persons with LLV had significantly higher levels of GDF-15 and D-dimer. These findings suggest a potential link between LLV and cardiovascular outcomes.

Cerebrospinal fluid abacavir concentrations in HIV-positive patients following once-daily administration.

Abacavir is a widely used nucleotide reverse transcriptase inhibitor, for which cerebrospinal fluid (CSF) exposure has been previously assessed in twice-daily recipients. We studied abacavir CSF concentrations in 61 and nine HIV-positive patients taking abacavir once daily and twice daily, respectively. Patients on once-daily abacavir had higher plasma and CSF concentrations (96 vs. 22 ng ml-1 , P = 0.038 and 123 vs. 49 ng ml-1 , P = 0.038) but similar CSF-to-plasma ratios (0.8 vs. 0.5, P = 0.500). CSF abacavir concentrations were adequate in patients receiving once-daily treatment.

Sweden, the first country to achieve the Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 continuum of HIV care targets.

OBJECTIVES: The Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 goals propose that 90% of all people living with HIV should know their HIV status, 90% of those diagnosed should receive antiretroviral therapy (ART), and 90% of those should have durable viral suppression. We have estimated the continuum of HIV care for the entire HIV-1-infected population in Sweden. METHODS: The Swedish InfCare HIV Cohort Study collects viral loads, CD4 counts, and viral sequences, along with demographic and clinical data, through an electronic clinical decision support system. Almost 100% of those diagnosed with HIV infection are included in the database, corresponding to 6946 diagnosed subjects living with HIV-1 in Sweden by 31 December 2015. RESULTS: Using HIV surveillance data reported to the Public Health Agency of Sweden, it was estimated that 10% of all HIV-infected subjects in Sweden remain undiagnosed. Among all diagnosed patients, 99.8% were linked to care and 97.1% of those remained in care. On 31 December 2015, 6605 of 6946 patients (95.1%) were on ART. A total of 6395 had been on treatment for at least 6 months and 6053 of those (94.7%) had a viral load < 50 HIV-1 RNA copies/mL. CONCLUSIONS: The 2014 UNAIDS/WHO 90-90-90 goals for HIV care means that > 73% of all patients living with HIV should be virologically suppressed by 2020. Sweden has already achieved this target, with 78% suppression, and is the first country reported to meet all the UNAIDS/WHO 90-90-90 goals.

Viral co-infection, autoimmunity, and CSF HIV antibody profiles in HIV central nervous system escape.

Antiretroviral therapy (ART) suppresses plasma and cerebrospinal fluid (CSF) HIV replication. Neurosymptomatic (NS) CSF escape is a rare exception in which CNS HIV replication occurs in the setting of neurologic impairment. The origins of NS escape are not fully understood. We performed a case-control study of asymptomatic (AS) escape and NS escape subjects with HIV-negative subjects as controls in which we investigated differential immunoreactivity to self-antigens in the CSF of NS escape by employing neuroanatomic CSF immunostaining and massively multiplexed self-antigen serology (PhIP-Seq). Additionally, we utilized pan-viral serology (VirScan) to deeply profile the CSF anti-viral antibody response and metagenomic next-generation sequencing (mNGS) for pathogen detection. We detected Epstein-Barr virus (EBV) DNA more frequently in the CSF of NS escape subjects than in AS escape subjects. Based on immunostaining and PhIP-Seq, there was evidence for increased immunoreactivity against self-antigens in NS escape CSF. Finally, VirScan revealed several immunodominant epitopes that map to the HIV envelope and gag proteins in the CSF of AS and NS escape subjects. Whether these additional inflammatory markers are byproducts of an HIV-driven process or whether they independently contribute to the neuropathogenesis of NS escape will require further study.

Severe multisystem inflammatory syndrome (MIS-C/A) after confirmed SARS-CoV-2 infection: a report of four adult cases.

BACKGROUND: Multisystem inflammatory syndrome (MIS) triggered by a recent SARS-Cov-2 infection has been recognised worldwide. Although predominantly affecting children (MIS-C), similar presentations have been reported among adults (MIS-A). METHOD: A retrospective case series describing four critically ill patients with MIS-C/A diagnosed between January and April 2021 at Sahlgrenska University Hospital, Gothenburg, Sweden. Clinical presentation, laboratory and radiological findings, treatment and outcome are reported. RESULTS: Cases occurred in previously healthy patients with a history of laboratory-confirmed mild SARS-CoV-2 infection four to seven weeks earlier. The median age was 24 years (range 19-43) and 3/4 were male. All fulfilled suggested MIS-C/A criteria according to the US Centre for Disease Control and all required care at an intensive care unit. Treatment was initiated with intravenous immunoglobulin, interleukin-1-receptor antagonists, and pulse steroids in 3/4 cases which resulted in rapid clinical improvement. No severe complications were noticed in any case during a three-month follow-up period. CONCLUSION: MIS-C/A should be considered, irrespective of age, in patients with fever, hyperinflammation and multiple organ system involvements emerging weeks after COVID-19. Previously suggested treatment regimens for MIS-C seem to be applicable also for MIS-A.

An intersectional analysis of sociodemographic disparities in Covid-19 vaccination: A nationwide register-based study in Sweden.

BACKGROUND: Studies on sociodemographic disparities in Covid-19 vaccination uptake in the general population are still limited and mostly focused on older adults. This study examined sociodemographic differences in Covid-19 vaccination uptake in the total Swedish population aged 18-64 years. METHODS: National Swedish register data within the SCIFI-PEARL project were used to cross-sectionally investigate sociodemographic differences in Covid-19 vaccination among Swedish adults aged 18-64 years (n = 5,987,189) by 12 October 2021. Using logistic regression models, analyses were adjusted for sociodemographic factors, region of residence, history of Covid-19, and comorbidities. An intersectional analysis approach including several cross-classified subgroups was used to further address the complexity of sociodemographic disparities in vaccination uptake. FINDINGS: By 12 October 2021, 76·0% of the Swedish population 18-64 years old had received at least two doses of Covid-19 vaccine, an additional 5·5% had received only one dose, and 18·5% were non-vaccinated. Non-vaccinated individuals were, compared to vaccinated, more often younger, male, had a lower income, were not gainfully employed, and/or were born outside Sweden. The social patterning for vaccine dose two was similar, but weaker, than for dose one. After multivariable adjustments, findings remained but were attenuated indicating the need to consider different sociodemographic factors simultaneously. The intersectional analysis showed a large variation in vaccine uptake ranging from 32% to 96% in cross-classified subgroups, reflecting considerable sociodemographic heterogeneity in vaccination coverage. INTERPRETATION: Our study, addressing the entire Swedish population aged 18-64 years, showed broad sociodemographic disparities in Covid-19 vaccine uptake but also wide heterogeneities in coverage. The intersectional analysis approach indicates that focusing on specific sociodemographic factors in isolation and group average risks without considering the heterogeneity within such groups will risk missing the full variability of vaccine coverage. FUNDING: SciLifeLab / Knut & Alice Wallenberg Foundation, Swedish Research Council, Swedish government ALF agreement, FORMAS.

Difference in drug resistance patterns between minor HIV-1 populations in cerebrospinal fluid and plasma.

OBJECTIVE: The aim of the study was to determine to what extent unique drug resistance patterns appear in minor and major HIV-1 quasispecies in cerebrospinal fluid (CSF) as compared with blood. METHODS: Forty-four plasma and CSF samples from 13 multi-treatment-experienced patients, seven of whom provided longitudinal samples, were included in the study. The subjects had failed antiretroviral therapy including lamivudine. The reverse transcriptase (RT) gene was examined by selective real-time polymerase chain reaction (SPCR), which can detect M184I/V mutants down to 0.2% of the viral population. RESULTS: SPCR revealed differences at amino acid position 184 in the plasma/CSF populations in 12 paired samples from eight patients. One plasma sample was positive by SPCR where direct sequencing showed wild-type M184. The other 11 paired samples showed quantitative differences in the mixed populations of the mutant or wild-type M184 quasispecies. Differences in other resistance-associated mutations between plasma and CSF viruses were also found by direct sequencing. CONCLUSIONS: In multi-treatment-experienced patients with therapy failure, differences in drug resistance patterns were found frequently between plasma and CSF in both minor and major viral populations. To what extent this was a true biological phenomenon remains to be established, and the clinical relevance of these findings is yet to be determined.

Comparison of HIV-1 pol and env sequences of blood, CSF, brain and spleen isolates collected ante-mortem and post-mortem.

OBJECTIVES: HIV-1 infects the central nervous system (CNS) early in the course of infection. However, it is not known to what extent the virus evolves independently within the CNS and whether the HIV-RNA in cerebrospinal fluid (CSF) reflects the viral population replicating within the brain parenchyma or the systemic infection. The aim of this study was to investigate HIV-1 evolution in the CNS and the origin of HIV-1 in CSF. MATERIALS AND METHODS: Longitudinally derived paired blood and CSF samples and post-mortem samples from CSF, brain and spleen were collected over a period of up to 63 months from three HIV-1 infected men receiving antiretroviral treatment and presenting with symptoms of AIDS dementia complex (ADC). RESULTS: Phylogenetic analyses of HIV-1 V3, reverse transcriptase (RT) and protease sequences from patient isolates suggest compartmentalization with distinct viral strains in blood, CSF and brain. We found a different pattern of RT and accessory protease mutations in the systemic infection compared to the CNS. CONCLUSIONS: We conclude that HIV-1 may to some extent evolve independently in the CNS and the viral population in CSF mainly reflects the infection in the brain parenchyma in patients with ADC. This is of importance in understanding HIV pathogenesis and can have implications on treatment of HIV-1 patients.

High levels in serum, but no signs of intrathecal synthesis of anti-sulfatide antibodies in HIV-1 infected individuals with or without central nervous system complications.

Myelin degeneration is commonly found in the central nervous system (CNS) of individuals infected with human immunodeficiency virus type 1 (HIV-1), especially in patients with HIV-1-associated dementia. We analysed cerebrospinal fluid (CSF) and serum samples from 25 HIV-1 infected individuals for the presence of antibodies directed against sulfatide, the major acidic glycosphingolipid in myelin. Nine of the patients had CNS complications, including 3 with HIV-1-associated dementia, and 16 had no neurological symptoms. Elevated titres of anti-sulfatide antibodies were found in serum from 24/25 HIV-1-infected individuals but in none of them in the CSF. Although the vast majority of HIV-1-infected individuals harbour autoantibodies directed against sulfatide in serum, the lack of detectable intrathecal production indicates that anti-sulfatide antibodies are not a major component in the pathogenesis of CNS myelin damage in HIV-1 infection.

Intrathecal immune activation is associated with cerebrospinal fluid markers of neuronal destruction in AIDS patients.

We analysed the relationship between cerebrospinal fluid (CSF) concentrations of the light subunit of the neurofilament protein (NFL, a marker of neurons, mainly axons), neopterin (a marker of immune activation), and quantitative HIV RNA levels in 47 patients with HIV-1 infection, 25 of whom had AIDS. In the AIDS patients, the mean levels of CSF NFL were high indicating neuronal destruction. The CSF NFL and the CSF neopterin concentrations were correlated in the subgroup of patients without CNS opportunistic infection (p < 0.05). There was no significant correlation between NFL and HIV RNA levels in CSF. In HIV seropositive patients without AIDS, only 3/22 had CSF NFL concentrations above the upper normal reference value. The results suggest that CNS neuronal destruction occurs frequently in patients with AIDS but rarely in those without AIDS, and that immune activation rather than the HIV viral load is associated with neurochemical signs of axonal destruction.

Elevated cerebrospinal fluid sulfatide concentrations as a sign of increased metabolic turnover of myelin in HIV type I infection.

Cerebrospinal fluid (CSF) sulfatide concentrations were analyzed in 18 patients with asymptomatic HIV-1 infection, in 16 patients with AIDS who were free from opportunistic infections in the central nervous system (CNS), in 12 HIV-1-infected patients with opportunistic CNS infections or lymphoma, and in 19 HIV-negative controls, by thin-layer chromatography overlay technique using an antisulfatide antibody to estimate the metabolic turnover of myelin. The majority of asymptomatic HIV-1-infected patients had normal CSF sulfatide concentrations, but the mean CSF sulfatide concentration was still elevated compared to that in HIV-negative controls (152 compared to 99 nmol/liter, p < 0.05). The CSF sulfatide concentrations in the AIDS group (mean 395 nmol/liter) were significantly increased compared to those in asymptomatic HIV-1-infected patients (p < 0.01) and in HIV-negative controls (p < 0.001), but did not differ significantly between patients with and without dementia. Increased CSF sulfatide concentrations were also found in patients with opportunistic infection or lymphoma in the CNS. In the entire study population, the sulfatide levels were associated with blood-brain barrier function, but not with intrathecal immunoglobulin production or with positive HIV isolations from CSF. Thus, signs of white matter changes, measured as increased CSF sulfatide concentrations, could be found in some asymptomatic HIV-1-infected patients, but the highest levels were seen in patients with AIDS.

Increased cerebrospinal fluid ganglioside GD3 concentrations as a marker of microglial activation in HIV type 1 infection.

Human immunodeficiency virus type 1 (HIV-1) invades the central nervous system (CNS) early in the infectious course. The predominant, productively infected cell type within the CNS is the microglial cell. We have analyzed the cerebrospinal fluid (CSF) levels of the ganglioside GD3, a microglia/macrophage and astrocyte marker, in 22 HIV-1-infected individuals at different stages of the disease, and in 44 age-matched HIV-negative, healthy controls. To distinguish between microglial/macrophage and astroglial involvement, the GD3 levels were compared with CSF levels of the glial fibrillary acidic protein (GFAp), which is expressed exclusively in astrocytes. A significantly higher mean CSF concentration of GD3 was found in HIV-1-infected patients compared to controls (56.7 and 40.1 nmol/L, respectively, p < 0.001). Seven of 22 HIV-1-infected patients had increased CSF levels of GD3 (above mean + 2 SD in controls), all but one of these had normal levels of GFAp, indicating a microglial activation or proliferation as the major source of the increased GD3 levels.

Tryptophan concentrations increase in cerebrospinal fluid and blood after zidovudine treatment in patients with HIV type 1 infection.

Cerebrospinal fluid (CSF) and blood concentrations of indoleamines and catecholamines were analyzed in 14 HIV-1-seropositive individuals before antiviral treatment with zidovudine, after 3-14 months of treatment, and, in 8 of the patients, also after 14-30 months. The median pretreatment concentrations of tryptophan in CSF and blood were low (224 ng/ml and 6.0 micrograms/ml, respectively), but an increase in these values by an average of 40% in CSF and 23% in blood was seen after 3-14 months of zidovudine treatment (p < 0.01) and remained undiminished after 14-30 months of treatment. No significant change was observed in the 5-hydroxytryptamine (5-HT, serotonin) level in blood or in the CSF concentrations of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the dopamine metabolite homovanillic acid (HVA). The CSF concentrations of the noradrenalin metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) had decreased by 12% on average (p < 0.01) by the time of the second follow-up, that is, after 14-30 months of zidovudine treatment. A decrease in neopterin during antiretroviral treatment correlated with an increase in tryptophan (p < 0.01). The data suggest that an association between decreased immune stimulation and reduced tryptophan degradation in patients treated with zidovudine.

Low cerebrospinal fluid beta-amyloid 42 in patients with acute bacterial meningitis and normalization after treatment.

CSF-A beta 42 may be a marker of Alzheimer's disease (AD). A decreased level of CSF-A beta 42 is consistently found in AD and has been suggested to be related to the deposition of amyloid plaques in the brain. However, low CSF-A beta 42 levels have also been found in disorders devoid of plaques, for instance Creutzfeldt-Jakob disease. To examine if the level of A beta 42 in CSF is related to inflammatory processes, we studied CSF-A beta 42 levels in eight patients with acute purulent bacterial meningitis, 10 patients with acute viral meningitis and 18 age-matched controls. In acute purulent bacterial meningitis, the CSF-A beta 42 level was markedly reduced (28% of that in controls, P<0.0001), whereas no change was found in viral meningitis. After successful treatment of bacterial meningitis, the CSF-A beta 42 level increased (P<0.05 compared to baseline) and did no longer differ from that in controls (ns). The decrease could not be explained by interference with high protein levels, since addition of increasing volumes of serum did not influence the CSF-A beta 42 levels. Our findings suggest that the reduction in CSF-A beta 42 found in bacterial meningitis is not a direct consequence of the inflammatory process. The cause may be disturbance of the clearance of A beta 42 from the brain.

Increased cerebrospinal fluid protein tau concentration in neuro-AIDS.

OBJECTIVES: Assessment of cerebrospinal fluid (CSF) levels of protein tau in human immunodeficiency virus type 1 (HIV-1) infection. MATERIAL AND METHODS: CSF tau levels were analyzed in 52 HIV-1-infected patients, 37 of whom had no neurological symptoms, eight had aquired immunodeficiency syndrome (AIDS) dementia complex (ADC), and seven had AIDS with other neurological complications. RESULTS: A significantly higher mean CSF tau concentration was found in patients with ADC (380 pg/ml) compared with patients with neuroasymptomatic HIV-1 infection (120 pg/ml, P<0.01) and HIV-negative controls (150 pg/ml, P<0.05). No difference in CSF tau levels was found between patients with ADC and patients with AIDS with other neurological complications. CONCLUSION: CSF tau might be used as a biochemical marker for axonal degeneration and might be of use to identify HIV-1-infected patients with ADC and other neurological complications, but it cannot discriminate between ADC and other neurological complications in HIV-1-infection.

Increase of tryptophan in serum and in cerebrospinal fluid of patients with HIV infection during zidovudine therapy.

A high percentage of patients with human immunodeficiency virus infection presents with decreased tryptophan concentrations in serum and cerebrospinal fluid. In parallel degradation products of tryptophan like kynurenine and quinolinic acid are increased. We investigated the behavior of tryptophan concentrations in 14 patients with HIV infection before and during treatment with zidovudine, and we found a significant increase of tryptophan in serum and cerebrospinal fluid after 4-14 months of therapy. In parallel, neopterin concentrations decreased significantly. Moreover, an association existed in cerebrospinal fluid between the degree of tryptophan increase and neopterin decrease. Thus, treatment with zidovudine contributes to a gradual normalization of tryptophan metabolism in patients with HIV-1 infection. The data imply that zidovudine therapy is associated not only with a reduction of virus replication but also immune activation is reduced.

CYP3A induction and inhibition by different antiretroviral regimens reflected by changes in plasma 4beta-hydroxycholesterol levels.

OBJECTIVE AND METHODS: A member of the major human cytochrome P450 superfamily of hemoproteins, CYP3A4/5, converts cholesterol into 4beta-hydroxycholesterol. We studied plasma 4beta-hydroxycholesterol levels prior to and 4 weeks after initiating antiretroviral therapy that included efavirenz, ritonavir-boosted atazanavir or ritonavir-boosted lopinavir with the aim of exploring the usefulness of plasma 4beta-hydroxycholesterol levels as an endogenous biomarker of CYP3A activity. Efavirenz is an inducer of CYP3A, whereas the ritonavir-boosted regimens are net inhibitors of CYP3A. RESULTS: In patients treated with efavirenz, the median plasma 4beta-hydroxycholesterol level increased by 46 ng/mL (p = 0.004; n = 11). In contrast, patients given ritonavir-boosted atazanavir showed a median decrease in plasma 4beta-hydroxycholesterol of -9.4 ng/mL (p = 0.0003; n = 22), and those given ritonavir-boosted lopinavir showed a median change from baseline of -5.8 ng/mL (p = 0.38; n = 19). There were significant between-group differences in the effects of antiretroviral treatment on plasma 4beta-hydroxycholesterol levels (p < 0.0001). CONCLUSION: Changes in plasma 4beta-hydroxycholesterol following the initiation of efavirenz- or atazanavir/ritonavir-based antiretroviral therapy reflected the respective net increase and decrease of CYP3A activity of these regimens. The plasma 4beta-hydroxycholesterol level did not indicate a net CYP3A inhibition in the lopinavir/ritonavir arm, possibly because of concomitant enzyme induction.