Absence of JC polyomavirus in stool samples of patients with multiple sclerosis despite high anti-JCV antibodies in serum.

BACKGROUND: Natalizumab is an effective treatment for relapsing multiple sclerosis (MS). During therapy, individuals are at increased risk of developing progressive multifocal leukoencephalopathy (PML). So far, the relevant reservoir for PML-type JC polyomavirus (JCV) remains elusive. We here tested if the detection of JCV-DNA in stool of persons with MS treated with natalizumab could be a future tool for PML risk assessment. METHODS: The presence of JCV-DNA in stool, urine, and whole blood of MS patients treated with natalizumab and known serum anti-JCV antibodies index values (IV) was studied. Different DNA extraction methods, real-time (RT) and droplet digital (dd) PCR techniques were compared. JCV isolates were screened for PML-associated variants by sequencing. RESULTS: Thirty MS patients treated with natalizumab were screened. For 21 patients, blood, stool, and urine samples were available. These patients were stratified according to their serum anti-JCV antibody IV (high (>1.5, n = 12); medium (1.5-0.9, n = 2); low (<0.9, n = 1); negative (n = 6)). JCV-DNA could not be detected in the whole blood or stool samples. Four urine samples had measurable JCV-DNA, ranging from 1.71×104-1.07×108 international units (IU)/mL detected by RT-PCR, corresponding to 4.62×104-9.85×106 copies/mL measured by ddPCR. All JCV variants were wild-type and derived from patients with high antibody IV. CONCLUSION: Stool-specific DNA extraction methods provided the highest quality of DNA, while the sensitivity of ddPCR and RT- PCR was comparable. Our findings do not support assessing stool samples for PML risk stratification in persons with MS. Further studies are needed to explore where PML-associated viral variants arise.

Cognitive decline in post-COVID-19 syndrome does not correspond with persisting neuronal or astrocytic damage.

Cognitive impairment is the most frequent symptom reported in post-COVID-19 syndrome (PCS). Aetiology of cognitive impairment in PCS is still to be determined. Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are increased in acute COVID-19. Their role as biomarkers in other neurological disorders is under debate. We analysed serum levels of NfL and GFAP as markers for neuronal and astrocytic damage in 53 patients presenting to a PCS Neurology outpatient clinic. Only individuals with self-reported cognitive complaints were included. In these individuals, cognitive complaints were further assessed by comprehensive neuropsychological assessment (NPA). Patients were categorized into subgroups of subjective cognitive decline, single domain impairment, or multi-domain impairment. Serum NfL was in normal range, however an increase of serum GFAP was detected in 4% of patients. Serum NfL and GFAP levels correlated with each other, even when adjusting for patient age (r = 0.347, p = 0.012). NPA showed deficits in 70%; 40% showing impairment in several tested domains. No significant differences were found between serum NfL- and GFAP-levels comparing patients with subjective cognitive decline, single domain impairment, or multi-domain impairment. Persistent neuronal or astrocytic damage did not correlate with cognitive impairment in PCS.

Cerebrospinal fluid findings in patients with neurological manifestations in post-COVID-19 syndrome.

BACKGROUND: Information on cerebrospinal fluid (CSF) findings in patients with neurological manifestations in post-COVID-19 syndrome is scarce. METHODS: Retrospective evaluation of 84 CSF samples in patients fulfilling post-COVID-19 criteria in two neurological post-COVID-19 outpatient clinics. RESULTS: In 68% of samples, all CSF parameters were normal. The most frequent pathological CSF finding was elevation of total protein (median total protein 33.3 mg/dl [total range 18.5-116.2]) in 20 of 83 (24%) samples. The second most prevalent pathological finding was a blood-CSF barrier dysfunction as measured by elevation of QAlb (median QAlb 4.65 [2.4-13.2]) in 11/84 (13%). Pleocytosis was found in only 5/84 (6%) samples and was mild in all of them. CSF-restricted oligoclonal bands were found in 5/83 (6%) samples. Anti-neuronal autoantibodies in CSF were negative in most cases, whilst 12/68 (18%) samples were positive for anti-myelin autoantibodies in serum. PCR for herpesviridae (HSV-1/-2, VZV, EBV, CMV, HHV6) showed, if at all, only weakly positive results in CSF or EDTA whole blood/plasma. CONCLUSIONS: The majority of samples did not show any pathologies. The most frequent findings were elevation of total protein and blood-CSF barrier dysfunction with no signs of intrathecal inflammation. CSF analysis still keeps its value for exclusion of differential diagnoses.

Immunomodulatory effects of intravenous and subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy: An observational study.

BACKGROUND AND PURPOSE: It is not known whether the route of administration affects the mechanisms of action of therapeutic immunoglobulin in chronic inflammatory demyelinating polyneuropathy (CIDP). The aim of this study, therefore, was to compare the immunomodulatory effects of intravenous (IVIg) and subcutaneous immunoglobulin (SCIg) in patients with CIDP and in IVIg-treated common variable immunodeficiency (CVID) patients. METHODS: Serum and peripheral blood mononuclear cell samples were obtained from 30 CIDP patients receiving IVIg, 10 CIDP patients receiving SCIg, and 15 patients with CVID receiving IVIg. Samples and clinical data were obtained prior to IVIg/SCIg and at 3 days, 7 days, and, in CIDP patients receiving IVIg, 21 days post-administration. Serum cytokines were assessed by Luminex-based multiplex assay and enzyme-linked immunosorbent assay. Immune cells were characterized by flow cytometry. RESULTS: Immune cell profiles of CIDP and CVID patients differed in frequencies of myeloid dendritic cells and cytotoxic natural killer cells. During treatment with IVIg or SCIg in CIDP patients, cellular immunomarkers were largely similar. CIDP patients receiving IVIg had higher macrophage inflammatory protein (MIP)-1α (p = 0.01), interleukin (IL)-4 (p = 0.04), and IL-33 (p = 0.04) levels than SCIg recipients. IVIg treatment more broadly modulated cytokines in CIDP than SCIg treatment. CONCLUSIONS: Our study demonstrates that the modulation of cellular immunomarkers in CIDP is independent of the application route of therapeutic immunoglobulin. Minor differences were observed between CIDP and CVID patients. In contrast, cytokines were differentially modulated by IVIg and SCIg in CIDP.

Progressive Multifocal Leukoencephalopathy: Pathogenesis, Diagnostic Tools, and Potential Biomarkers of Response to Therapy.

JC polyomavirus (JCV) establishes an asymptomatic latent and/or persistent infection in most of the adult population. However, in immunocompromised individuals, JCV can cause a symptomatic infection of the brain, foremost progressive multifocal leukoencephalopathy (PML). In the past 2 decades, there has been increasing concern among patients and the medical community because PML was observed as an adverse event in individuals treated with modern (selective) immune suppressive treatments for various immune-mediated diseases, especially multiple sclerosis. It became evident that this devastating complication also needs to be considered beyond the patient populations historically at risk, including those with hematologic malignancies or HIV-infected individuals. We review the clinical presentation of PML, its variants, pathogenesis, and current diagnostic approaches. We further discuss the need to validate JCV-directed interventions and highlight current management strategies based on early diagnosis and restoring JCV-specific cellular immunity, which is crucial for viral clearance and survival. Finally, we discuss the importance of biomarkers for diagnosis and response to therapy, instrumental in defining sensitive study end points for successful clinical trials of curative or preventive therapeutics. Advances in understanding PML pathophysiology, host and viral genetics, and diagnostics in conjunction with novel immunotherapeutic approaches indicate that the time is right to design and perform definitive trials to develop preventive options and curative therapy for JCV-associated diseases.

Adoptive Allogeneic T-Cell Therapy Improves the Clinical Outcome of JC Virus Granule Cell Neuronopathy: A Case Report.

OBJECTIVES: JC virus granule cell neuronopathy is a potentially fatal otherwise highly disabling disease without an approved therapeutic option. This case report presents the positive record to T-cell therapy in JC virus granule cell neuronopathy. METHODS: The patient represented with subacute cerebellar symptoms. Diagnosis of JC virus granule cell neuronopathy was made because of infratentorially accentuated brain volume atrophy shown by brain MRI and the detection of JC virus DNA in the CSF. RESULTS: Six doses of virus-specific T cells were administered. Within 12 months after therapy initiation, the patient showed clear clinical benefit with improvement of symptoms, and JC viral DNA load significantly declined. DISCUSSION: We present the case report of a positive response to T-cell therapy in JC virus granule cell neuronopathy, leading to an improvement of symptoms.

CIDP: Analysis of Immunomarkers During COVID-19 mRNA-Vaccination and IVIg-Immunomodulation: An Exploratory Study.

Availability of COVID-19 mRNA vaccine for patients with chronic inflammatory demyelinating polyneuropathy (CIDP) treated with intravenous immunoglobulin (IVIg) raises the question of whether COVID-19 mRNA vaccine influences disease activity or IVIg-mediated immunomodulation in CIDP. In this exploratory study, blood samples of CIDP patients on IVIg treatment were longitudinally analyzed before and after vaccination with a COVID-19 mRNA vaccine. A total of 44 samples of eleven patients were characterized at four timepoints by ELISA and flow cytometry in terms of immunomarkers for disease activity and IVIg-immunomodulation. Apart from a significantly lower expression of CD32b on naïve B cells after vaccination, no significant alteration of immunomarkers for CIDP or IVIg-mediated immunomodulation was observed. Our exploratory study suggests that COVID-19 mRNA vaccine does not have a relevant impact on immune activity in CIDP. In addition, immunomodulatory effects of IVIg in CIDP are not altered by COVID-19 mRNA vaccine. This study was registered in the German clinical trial register (DRKS00025759). Overview over the study design. Blood samples of CIDP patients on recurrent IVIg treatment and vaccination with a COVID-19 mRNA vaccine were obtained at four timepoints for cytokine ELISA and flow cytometry, to assess key cytokines and cellular immunomarkers for disease activity and IVIg-immunomodulation in CIDP.

Association of cerebrospinal fluid brain-binding autoantibodies with cognitive impairment in post-COVID-19 syndrome.

BACKGROUND: Neurological symptoms, in particular cognitive deficits, are common in post-COVID-19 syndrome (PCS). There is no approved therapy available, and the underlying disease mechanisms are largely unknown. Besides others, autoimmune processes may play a key role. DESIGN: We here present data of a prospective study conducted between September 2020 and December 2021 and performed at two German University hospitals with specialized Neurology outpatient clinics. Fifty patients with self-reported cognitive deficits as main complaint of PCS and available serum and CSF samples were included. Cell-based assays and indirect immunofluorescence on murine brain sections were used to detect autoantibodies against intracellular and surface antigens in serum and CSF and analyzed for associations with cognitive screening assessment. RESULTS: Clearly abnormal cognitive status (MoCA ≤ 25/30 points) was only seen in 18/50 patients with self-reported cognitive deficits. Most patients (46/50) had normal routine CSF parameters. anti-neuronal autoantibodies were found in 52 % of all patients: n = 9 in serum only, n = 3 in CSF only and n = 14 in both, including those against myelin, Yo, Ma2/Ta, GAD65 and NMDA receptor, but also a variety of undetermined epitopes on brain sections. These included cerebral vessel endothelium, Purkinje neurons, granule cells, axon initial segments, astrocytic proteins and neuropil of basal ganglia or hippocampus as well as a formerly unknown perinuclear rim pattern. Pathological MoCA results were associated with the presence of anti-neuronal antibodies in CSF (p = 0.0004). CONCLUSIONS: Autoantibodies targeting brain epitopes are common in PCS patients and strongly associate with pathological cognitive screening tests, in particular when found in CSF. Several underlying autoantigens still await experimental identification. Further research is needed to inform on the clinical relevance of these autoantibodies, including controlled studies that explore the potential efficacy of antibody-depleting immunotherapy in PCS.

Multidomain cognitive impairment in non-hospitalized patients with the post-COVID-19 syndrome: results from a prospective monocentric cohort.

BACKGROUND: A fraction of patients with asymptomatic to mild/moderate acute COVID-19 disease report cognitive deficits as part of the post-COVID-19 syndrome. This study aimed to assess the neuropsychological profile of these patients. METHODS: Assessment at baseline (three months or more following acute COVID-19) of a monocentric prospective cohort of patients with post-COVID-19 syndrome. Multidomain neuropsychological tests were performed, and questionnaires on depression, anxiety, fatigue, sleep, and general health status were administered. RESULTS: Of the 58 patients screened, six were excluded due to possible alternative causes of cognitive impairment (major depression, neurodegenerative disease). Of the remaining 52 individuals, only one had a below-threshold screening result on Mini-Mental State Examination, and 13 scored below the cut-off on Montreal Cognitive Assessment. Extended neuropsychological testing revealed a neurocognitive disorder (NCD) in 31 (59.6%) participants with minor NCD in the majority of cases (n = 26). In patients with NCD, the cognitive domains learning/memory and executive functions were impaired in 60.7%, complex attention in 51.6%, language in 35.5%, and perceptual-motor function in 29.0%. Cognitive profiles were associated with daytime sleepiness but not with depression, anxiety, sleep quality, total general health status, or fatigue. CONCLUSION: Neurocognitive impairment can be confirmed in around 60% of individuals with self-reported deficits as part of post-COVID-19 syndrome following a mild acute COVID-19 disease course. Notably, screening tests cannot reliably detect this dysfunction. Standard psychiatric assessments showed no association with cognitive profiles. Longitudinal studies are needed to further evaluate the course of neurocognitive deficits and clarify pathophysiology.

A therapeutic vaccine strategy to prevent Pneumocystis pneumonia in an immunocompromised host in a non-human primate model of HIV and Pneumocystis co-infection.

Introduction: Pneumocystis is a ubiquitous fungal pathogen that causes pneumonia (PCP) and pulmonary sequelae in HIV-infected individuals and other immunocompromised populations. With the success of anti-retroviral therapy for HIV-infected individuals the frequency of PCP in that population has decreased, however, PCP remains a significant cause of morbidity and mortality in individuals with hematologic and solid malignancies, and in individuals treated with immunosuppressive therapies for autoimmune diseases, and following bone marrow and solid organ transplantation. Despite the clinical need, there is no approved vaccine to prevent PCP in vulnerable populations. The ultimate goal of the field is to develop an effective vaccine that can overcome immune deficits in at risk populations and induce long-lasting protective immunity to Pneumocystis. Toward this goal, our laboratory has established a model of PCP co-infection in simian immunodeficiency virus (SIV)-infected non-human primates (NHP) and identified a recombinant protein sub-unit vaccine, KEX1, that induces robust anti-Pneumocystis immunity in immune-competent macaques that is durable and prevents PCP following simian immunodeficiency virus (SIV)-induced immunosuppression. Type I, or invariant natural killer T (iNKT) cells have the potential to provide B cell help under conditions of reduced CD4+ T cell help. Methods: In the present study, we used the SIV model of HIV infection to address whether therapeutic vaccination with the iNKT cell-activating adjuvant α-galactosylceramide (α-GC) and KEX1 (α-GC+KEX1) can effectively boost anti-Pneumocystis humoral immunity following virus-induced immunosuppression. Results: Immunization of antigen-experienced NHPs with α-GC+KEX1 during the early chronic phase of SIV-infection significantly boosted anti-Pneumocystis humoral immunity by increasing memory B cells and antibody titers, and enhanced titer durability during SIV-induced immunosuppression. This therapeutic vaccination strategy boosted anti-Pneumocystis immune responses during SIV-infection and contributed to protection against Pneumocystis co-infection in KEX1-vaccinated macaques. Conclusion: These studies present a novel strategy for stimulating durable anti-Pneumocystis humoral immunity in the context of complex, chronic SIV-induced immunosuppression and may be further applied to immunization of other immunosuppressed populations, and toward other common recall antigens.

Antibody response after COVID-19 vaccination in intravenous immunoglobulin-treated immune neuropathies.

BACKGROUND AND PURPOSE: This study assessed the prevalence of anti-SARS-CoV-2 antibodies in therapeutic immunoglobulin and their impact on serological response to COVID-19 mRNA vaccine in patients with intravenous immunoglobulin (IVIg)-treated chronic immune neuropathies. METHODS: Forty-six samples of different brands or lots of IVIg or subcutaneous IgG were analyzed for anti-SARS-CoV-2 IgG using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Blood sera from 16 patients with immune neuropathies were prospectively analyzed for anti-SARS-CoV-2 IgA, IgG, and IgM before and 1 week after IVIg infusion subsequent to consecutive COVID-19 mRNA vaccine doses and after 12 weeks. These were compared to 42 healthy subjects. RESULTS: Twenty-four (52%) therapeutic immunoglobulin samples contained anti-SARS-CoV-2 IgG. All patients with immune neuropathies (mean age = 65 ± 16 years, 25% female) were positive for anti-SARS-CoV-2 IgG after COVID-19 vaccination. Anti-SARS-CoV-2 IgA titers significantly decreased 12-14 weeks after vaccination (p = 0.02), whereas IgG titers remained stable (p = 0.2). IVIg did not significantly reduce intraindividual anti-SARS-CoV-2 IgA/IgG serum titers in immune neuropathies (p = 0.69). IVIg-derived anti-SARS-CoV-2 IgG did not alter serum anti-SARS-CoV-2 IgG decrease after IVIg administration (p = 0.67). CONCLUSIONS: Our study indicates that IVIg does not impair the antibody response to COVID-19 mRNA vaccine in a short-term observation, when administered a minimum of 2 weeks after each vaccine dose. The infusion of current IVIg preparations that contain anti-SARS-CoV-2 IgG does not significantly alter serum anti-SARS-CoV-2 IgG titers.

Cerebrospinal Fluid Analysis Post-COVID-19 Is Not Suggestive of Persistent Central Nervous System Infection.

This study was undertaken to assess whether SARS-CoV-2 causes a persistent central nervous system infection. SARS-CoV-2-specific antibody index and SARS-CoV-2 RNA were studied in cerebrospinal fluid following COVID-19. Cerebrospinal fluid was assessed between days 1 and 30 (n = 12), between days 31 and 90 (n = 8), or later than 90 days (post-COVID-19, n = 20) after COVID-19 diagnosis. SARS-CoV-2 RNA was absent in all patients, and in none of the 20 patients with post-COVID-19 syndrome were intrathecally produced anti-SARS-CoV-2 antibodies detected. The absence of evidence of SARS-CoV-2 in cerebrospinal fluid argues against a persistent central nervous system infection as a cause of neurological or neuropsychiatric post-COVID-19 syndrome. ANN NEUROL 2022;91:150-157.

Neuro-COVID-19 is more than anosmia: clinical presentation, neurodiagnostics, therapies, and prognosis.

PURPOSE OF REVIEW: To provide an overview on current knowledge of neurological symptoms and complications of COVID-19, and to suggest management concepts. RECENT FINDINGS: Headache, dizziness, excessive tiredness, myalgia, anosmia/hyposmia, and ageusia/dysgeusia are common nonspecific neurological manifestations during early COVID-19 disease found in the majority of patients. Less frequent but more severe and specific neurological manifestations include Guillain--Barré syndrome, encephalopathy, encephalitis/meningitis, epileptic seizures, and cerebrovascular events. Beyond standard neurological examination, these require a more extensive work-up, including cerebrospinal fluid assessment, neurophysiological evaluation, neuroimaging, and cognitive testing. Symptomatic treatment is advisable unless the neurological complication's immune pathogenesis is proven. SUMMARY: Neurological manifestations of COVID-19 occur during the acute, para-infectious, and 'recovery' phase. Therapeutic management depends on the clinical presentation and neurological work-up.

A systematic review of neurological symptoms and complications of COVID-19.

OBJECTIVE: To study the frequency of neurological symptoms and complications in COVID-19 patients in a systematic review of the literature. METHODS: Relevant studies were identified through electronic explorations of PubMed, medRxiv, and bioRxiv. Besides, three Chinese databases were searched. A snowballing method searching the bibliographies of the retrieved references was applied to identify potentially relevant articles. Articles published within 1 year prior to April 20th, 2020, were screened with no language restriction imposed. Databases were searched for terms related to SARS-CoV-2/COVID-19 and neurological manifestations, using a pre-established protocol registered on the International Prospective Register of Systematic Reviews database (ID: CRD42020187994). RESULTS: A total of 2441 articles were screened for relevant content, of which 92 full-text publications were included in the analyses of neurological manifestations of COVID-19. Headache, dizziness, taste and smell dysfunctions, and impaired consciousness were the most frequently described neurological symptoms, the latter more often among patients with a severe or critical disease course. To date, only smaller cohort studies or single cases have reported cerebrovascular events, seizures, meningoencephalitis, and immune-mediated neurological diseases, not suitable for quantitative analysis. CONCLUSION: The most frequent neurological symptoms reported in association with COVID-19 are non-specific for the infection with SARS-CoV-2. Although SARS-CoV-2 may have the potential to gain direct access to the nervous system, so far, SARS-CoV-2 was detected in the cerebrospinal fluid in two cases only. Standardized international registries are needed to clarify the clinical relevance of the neuropathogenicity of SARS-CoV-2 and to elucidate a possible impact of SARS-CoV-2 infection on common neurological disease, such as Alzheimer's, Parkinson's disease or multiple sclerosis.

Statin treatment prevents the development of pulmonary arterial hypertension in a nonhuman primate model of HIV-associated PAH.

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by pulmonary vascular remodeling, elevated pulmonary arterial pressure, and right heart failure. Human immunodeficiency virus (HIV)-infected individuals have a higher incidence of PAH than the non-HIV infected population and evidence suggests a role for systemic and pulmonary inflammation in the pathogenesis of HIV-associated PAH. Due to their pleiotropic effects, including immune-modulatory and anti-inflammatory effects, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been considered for the treatment of PAH, with conflicting results. The effects of statins on HIV-associated PAH have not been specifically evaluated. We have developed a non-human primate (NHP) model of HIV-associated PAH that closely mimics HIV-PAH using simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta). We determined that treatment of healthy macaques with atorvastatin prior to and throughout SIV infection prevented the development of SIV-associated PAH. Additionally, SIV-infected macaques that initiated atorvastatin treatment during the early chronic disease stage had reduced incidence of PAH compared to untreated animals. Statin treatment reduced inflammatory mediators TGF-ß, MIP-1α, and TNF-α and the numbers of CD14dimCD16+ non-classical monocytes, and CD14+CCR7-CD163-CD206+ alveolar macrophages previously shown to be associated with SIV-PAH. These results support the concept that statins reduce inflammatory processes that contribute to PAH and may provide a safe and effective prophylactic strategy for the prevention of PAH in HIV-infected individuals.

Age and the risks of high-efficacy disease modifying drugs in multiple sclerosis.

PURPOSE OF REVIEW: A variety of high-efficacy disease-modifying therapies (DMTs) are available for the treatment of multiple sclerosis (MS). After evaluation and approval by regulatory agencies, DMTs are likely to be administered to patients whose characteristics differ from those enrolled in clinical trials. This may contribute to the emergence of unexpected adverse events observed in the real-world setting. Higher age may be a relevant factor that could change the benefit-risk balance of DMTs, as it may associate with lower efficiency and higher frequency of adverse events. RECENT FINDINGS: The absolute and relative number of patients with MS who reach the age of 55 and higher increases. Growing evidence demonstrates lower efficacy of DMTs in older persons with MS. Specific risks during DMTs for MS, such as the risk of developing progressive multifocal leukoencephalopathy (PML) or the outcome following PML, have been associated with age. It is hypothesized that age-related and therapy-induced alterations to the immune system may have (super)additive effects, resulting in an acceleration of physiological immunosenescence and inflamm-aging. SUMMARY: In this article, we review the risks of high-efficacy DMTs in MS with a specific focus on age-related efficacy and risks, including opportunistic infections, malignancies, and autoimmune reactions.

Monocyte and Alveolar Macrophage Skewing Is Associated with the Development of Pulmonary Arterial Hypertension in a Primate Model of HIV Infection.

We investigated the relationship of monocytes, alveolar, and tissue-resident macrophage populations and the development of pulmonary arterial hypertension (PAH) in a nonhuman primate model of HIV infection. A prospective study of simian immunodeficiency virus-associated pulmonary arterial hypertension (SIV-PAH) was done. Rhesus macaques (n = 21) were infected with SIV. Blood, bronchoalveolar lavage fluid (BALF), and lung tissue were analyzed for monocyte and macrophage phenotypes and inflammatory mediators. Serial right heart catheterizations were performed at three time points throughout the study to assess hemodynamic alterations and the development of PAH. All 21 animals showed similar courses of SIV infection with an increasing proinflammatory plasma environment. At 6 months postinfection (mpi), 11 of 21 animals developed SIV-PAH (mPAP ≤25 mmHg; right ventricular systolic pressure [RVSP] ≤36 mmHg). PAH+ animals had an increased frequency of proinflammatory, nonclassical monocytes (CD14dimCD16+) (p = .06) in the peripheral blood and CD14+CCR7-CD163-CD206+ macrophages (p = .04) in BALF compared with PAH- animals at 6 mpi. Increased frequencies of these monocyte and macrophage phenotypes correlated with elevated RVSP (p = .04; p = .03). In addition, PAH+ animals had greater frequencies of tissue resident inflammatory M1-like CD68+STAT1+ (p = .001) and M2a-like CD68+STAT3+ macrophages (p = .003) and a lower frequency of anti-inflammatory M2c-like CD68+STAT6+ macrophages (p = .003) as well as fewer interleukin (IL)-10+ cells (p = .01). The results suggest that HIV-PAH is associated with skewing of monocytes and alveolar macrophages toward a proinflammatory, profibrotic phenotype. Furthermore, PAH+ animals may have diminished capacity to downregulate exaggerated chronic inflammation, as indicated by lower levels of IL-10 in PAH+ animals, contributing to disease progression.

Longitudinal Evaluation of Pulmonary Arterial Hypertension in a Rhesus Macaque (Macaca mulatta) Model of HIV Infection.

Pulmonary arterial hypertension (PAH) is a life-threatening disease with higher incidence in HIV-infected compared with noninfected patients. SIV-infected NHP develop clinical manifestations of HIV infection, including PAH. To understand the pathogenesis of PAH and determine the relationship between hemodynamic changes and clinical characteristics associated with SIV infection, we performed right heart catheterization and echocardiographic imaging of 21 rhesus macaques before and after SIV infection. Between 6 and 12 mo after infection, 11 of the 21 animals had elevated mean pulmonary arterial pressure (mPAP; greater than 25 mm Hg). RV involvement was evident as increased RV glucose uptake in PAH+ macaques on positron emission tomography-coupled CT compared with uninfected animals. RV and pulmonary vascular collagen deposition were elevated in PAH+ animals. At 12 mo after infection, 6 of the 21 macaques (28.6%) exhibited continued increase in mPAP (progressive PAH), whereas 5 animals (23.8%) had reduced pressure (transient PAH). SIV infection of rhesus macaques led to 3 distinct outcomes with regard to hemodynamic function. Hemodynamic alterations correlated with specific inflammatory profiles and increased RV and pulmonary arterial fibrosis but not with viral load, sex, or CD4+ T-cell levels. This model of a natural cause of PAH provides insight into disease pathways that are important for the development of novel therapeutic targets.

Longitudinal comparison of HIV-1 plasma viral load and cellular proviral load.

INTRODUCTION: The goal of antiretroviral treatment (ART) in HIV-1 infection is the permanent suppression of plasma viral load (pVL) below the currently existing limit of detection of 50 copies/mL (DAIG HIV-therapy guidelines). Therefore, treatment effectiveness is based on pVL. pVL measurements however do not give any information about the viral reservoir in peripheral blood mononuclear cells (PBMCs). Therefore, the proviral DNA of HIV-1 could be a useful marker for the investigation of viral reservoirs and monitoring ART in patients showing undetectable pVL. MATERIALS AND METHODS: Seventy-seven treatment-experienced HIV-1 infected patients with pVL <50 copies/mL were randomly selected. pVL and proviral DNA load were measured using the Roche COBAS TaqMan HIV-1 v2.0 assay. Additionally, CD4+ cell count per mL and the total white blood cell (wbc) count per mL were determined for each patient. Follow-up data were collected 24 weeks after the time point of the first measurement. Proviral DNA load per mL, CD4+ cell count per mL as well as wbc count per mL were observed over time and differences were estimated using the Mann-Whitney U test. Additionally, correlations between the clinical parameters were analyzed using the two-sided Pearson correlation analysis. RESULTS: Out of the 77 patients, 38 show a significant increase in proviral load per mL over time (p=0,001), whereas 39 patients show a significant decrease (p=0,001). No differences became visible in the CD4+ cell count per mL comparing week 0 and week 24 data. Thirty five patients show a significant increase in wbc count per mL over time (p<0,001), while 42 patients show a significant decrease (p<0,001). A significant correlation of increasing proviral load per mL and wbc count per mL for data of the first (p<0.001) and the second measurement (p<0.001) can be detected, while there are no correlations found between proviral load per mL and CD4+ cell count per mL. CONCLUSIONS: Our data show that the presence of viral reservoirs in other cell types and not only CD4+ cells is most probable. HIV-1 proviral DNA seems to be an interesting marker in patients with undetectable pVL and allows the assessment of replication under ART. Nevertheless, further longitudinal studies are needed to assess the usefulness and the clinical significance of this marker.

Influence of major HIV-1 protease inhibitor resistance mutations on CTL recognition.

BACKGROUND: HIV-1 protease is subjected to dual selection pressure exerted by protease inhibitors (PIs) and cytotoxic T lymphocytes (CTL). Recently, we identified KMIGGIGGF (KF9) as a HLA-B*1501-restricted CTL epitope, including several major PI resistance mutations (M46I/L, I47A/V, G48V, I50V). To assess potential interactions between KF9-specific CTL and emergence of these important resistance mutations, we studied CTL recognition of the mutations and analyzed protease sequences in an HLA-I­typed patient cohort. METHODS: CTL recognition of KF9 and resistance mutations in KF9 were studied in 38 HLA-B*1501-positive HIV-1­infected patients using variant KF9 peptides in interferon-g enzyme-linked immunospot assays. Protease sequences were analyzed in 302 HLA-I­typed HIV-1­infected patients. RESULTS: G48V abolished KF9 recognition by CTL in all patients. Furthermore, M46I, I47A, and I50V could impair or abolish CTL recognition in many patients. In contrast, M46L and I47V showed good CTL recognition in nearly all patients. HIV-1 protease sequence analysis showed no statistical correlation between the occurrence of resistance mutations in KF9 and HLA-B*1501. Viral load in patients failing therapy with KF9 mutations was significantly lower in HLA-B*1501-positive patients in comparison with HLA-B*1501-negative patients. CONCLUSIONS: PI mutations, G48V, M46I, and I47A, can abrogate CTL recognition, indicating potential interactions between development of drug resistance and CTL response. However, we could not find evidence that development of these PI mutations is influenced by KF9-specific CTL.