Strategies to determine positive anti-SARS-CoV-2 memory T lymphocyte response during the evolution of an epidemic.

During SARS-CoV-2 pandemic, the assessment of immune protection of people at risk of severe infection was an important goal. The appearance of VOCs (Variant of Concern) highlighted the limits of evaluating immune protection through the humoral response. While the humoral response partly loses its neutralizing activity, the anti-SARS-CoV-2 memory T cell response strongly cross protects against VOCs becoming an indispensable tool to assess immune protection. We compared two techniques available in laboratory to evaluate anti-SARS-CoV-2 memory T cell response in a cohort of infected or vaccinated patients with different levels of risk to develop a severe disease: the ELISpot assay and the T-Cell Lymphocyte Proliferation Assay respectively exploring IFNγ production and cell proliferation. We showed that the ELISpot assay detected more anti-Spike memory T cell response than the Lymphocyte Proliferation Assay. We next observed that the use of two different suppliers as antigenic source in the ELISpot assay did not affect the detection of anti-Spike memory T cell response. Finally, we explored a new approach for defining the positivity threshold, using unsupervised mixed Gaussian modeling, challenging the traditional ROC curve used by the supplier. That will be helpful in endemic situation where it could be difficult to recruit "negative" patients.

Rapid decrease in IL-1Ra and IP-10 plasma levels following tuberculosis treatment initiation.

OBJECTIVES: Monitoring tools that could provide quick predictions of tuberculosis (TB) treatment outcomes are urgently needed. Here, we assessed whether the evolution of selected biomarkers of innate immunity may help monitoring TB treatment response within 2 weeks of treatment initiation. METHODS: ANRS12394-LILAC-TB was a proof-of-concept prospective study: adults with a rifampicin-susceptible TB who are HIV-negative and HIV-infected documented by a positive Xpert MTB/RIF test were enrolled in Cambodia and Côte d'Ivoire. Plasma concentrations of interleukin-1 receptor antagonist (IL-1Ra), interferon-γ-induced protein-10 and clusters of differentiation (CD) (scavenging CD163) were measured by commercial enzyme-linked immunosorbent assay kits. A Wilcoxon test for paired data was used for longitudinal comparisons. RESULTS: A total of 55 patients were enrolled (women: 31%, median age: 37 years; median CD4 count in the 10 of 13 participants with HIV: 53 cells/mm3). Overall, 83% were considered in TB treatment success. Compared with baseline, the IL-1Ra plasma levels significantly decreased as soon as week (W) 1, independent of HIV status (-71% in HIV-positive vs -33% in HIV-negative; P <0.001). The IP-10 plasma levels significantly decreased at W1 and W2 compared with baseline (P <0.0001); however, that decrease was less marked in participants with HIV. CONCLUSIONS: Our findings suggest that measuring IL-1Ra plasma levels with a standard enzyme-linked immunosorbent assay technique at baseline and then 1 week after TB treatment onset could help clinicians to quickly assess TB treatment response.

Optimizing COVID-19 Vaccination Strategy in Pediatric Kidney Transplant Recipients: Humoral and Cellular Response to SARS-CoV-2 mRNA Vaccination.

In this retrospective cohort study, we analyze the early humoral and cellular response in 64 adolescents KTx recipients, after two or three doses of mRNA vaccine BNT162b2 against different variants of COVID-19. After 2 doses, 77.8% % of children with no history of infection had a positive humoral response with a median anti-S IgG level of 1107 (IQR, 593-2,658) BAU/mL. All the patients with a history of infection responded with a higher median IgG level (3,265 (IQR, 1,492-8,178) BAU/mL). In non-responders after 2 doses, 75% responded after a third dose with a median Ab titer at 355 (IQR, 140-3,865 BAU/mL). Neutralizing activity was significantly lower against the delta and the omicron variants compared to the wild-type strain and did not improve after a 3rd dose, while infection did provide higher levels of neutralizations against the variants. T cell specific response correlated with humoral response and no patient displayed a cellular response without a humoral response. Adolescent KTx recipients exhibit a high seroconversion rate after only two doses. A third injection, induces a response in the majority of the non-responders patients but did not counterbalance the strong decrease in neutralizing antibody activities against variants highlighting the need for boosters with specific vaccines.

Characteristics of circulating KSHV-infected viroblasts during active KSHV+ multicentric Castleman disease.

Kaposi sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8-associated multicentric Castleman disease (MCD) is a polyclonal B-cell lymphoproliferative disorder that mainly occurs in immunocompromised hosts. The diagnosis relies on lymph node biopsy demonstrating KSHV-infected cells located in the mantle zone with a marked interfollicular plasma cell infiltration. Infected cells are large cells positive for immunoglobulin M (IgM), λ light chain, and CD38, described initially as infected plasmablasts. We show that IgM+λ+CD38high cells were also detectable in the peripheral blood of 14 out of 18 (78%) patients with active KSHV-MCD and absent in 40 controls. Using immunofluorescence and flow-fluorescence in situ hybridization, we demonstrate that these cells are KSHV infected and express both latent and lytic KSHV transcripts. These KSHV-infected viroblasts (KIVs) harbor a distinct phenotype compared with conventional plasmablasts. We also identified several putative mechanisms of immune escape used by KSHV, because KIVs displayed an overall decrease of costimulatory molecules, with a remarkable lack of CD40 expression and are interleukin-10-producing cells. The identification of this specific and easily accessible KSHV+ circulating population brings new elements to the understanding of KSHV-MCD but also raises new questions that need to be clarified.

Comparison between enzyme-linked immunospot assay and intracellular cytokine flow cytometry assays for the evaluation of T cell response to SARS-CoV-2 after symptomatic COVID-19.

INTRODUCTION: Evaluation of different cell-based assays for the study of adaptive immune responses against SARS-CoV-2 is crucial for studying long-term and vaccine-induced immunity. METHODS: Enzyme-linked immunospot assay (ELISpot) and intracellular cytokine staining (ICS) using peptide pools spanning the spike protein and nucleoprotein of SARS-CoV-2 were performed in 25 patients who recovered from paucisymptomatic (n = 19) or severe COVID-19 (n = 6). RESULTS: The proportion of paucisymptomatic patients with detectable SARS-CoV-2 T cells was low, as only 44% exhibit a positive T cell response with the ICS and 67% with the ELISpot. The magnitude of SARS-CoV-2 T cell responses was low, both with ICS (median at 0.12% among total T cells) and ELISpot (median at 61 SFCs/million peripheral blood mononuclear cells [PBMC]) assays. Moreover, T cell responses in paucisymptomatic patients seemed lower than among patients with severe disease. In the paucisymptomatic patients, the two assays were well correlated with 76% of concordant responses and a Cohen's kappa of 55. Furthermore, in four patients SARS-CoV-2 T cells were detected by ELISpot but not with ICS. Short-term culture could improve the detection of specific T cells. CONCLUSIONS: In patients who recovered from paucisymptomatic COVID-19, the proportion of detectable anti-SARS-CoV-2 responses and their magnitude seemed lower than in patients with more severe symptoms. The ELISpot appeared to be more sensitive than the ICS assay. Short-term culture revealed that paucisymptomatic patients had nonetheless few SARS-CoV-2 T cells at a very low rate in peripheral blood. These data indicate that various ex-vivo assays may lead to different conclusions about the presence or absence of SARS-CoV-2 T cell immunity.

PD-1 blockade with pembrolizumab in classic or endemic Kaposi's sarcoma: a multicentre, single-arm, phase 2 study.

BACKGROUND: Although the treatment of iatrogenic and HIV-related Kaposi sarcoma is well defined and mostly based on restoring immune function, the treatment of classic and endemic Kaposi sarcoma is less well established. Chemotherapy or interferon α is used for patients with extensive cutaneous or visceral Kaposi sarcoma, but tolerance might be poor and long-term remission is rare. We aimed to evaluate the activity of pembrolizumab in classic and endemic Kaposi sarcoma with cutaneous extension requiring systemic treatment. METHODS: We did a multicentre, single-arm, proof-of-concept, phase 2 trial in adults aged 18 years or older with histologically proven classic or endemic Kaposi's sarcoma with progressive cutaneous extension requiring systemic treatment and an Eastern Cooperative Oncology Group performance status of 0-1 in three hospitals in France. The patients were treated with 200 mg pembrolizumab intravenously every 3 weeks for 6 months (eight cycles) or until severe toxicity. The primary endpoint was the best overall response rate within the 6-month timeframe, defined by the occurrence of a complete response or partial response and assessed by an investigator using the modified AIDS Clinical Trial Group (ACTG) criteria. Three or more responses among a total 17 patients were needed for the primary endpoint to be met, using a Simon's two-stage optimal design assuming a 30% response rate as desirable. For this final study analysis, all patients were included following the intention-to-treat principle. This study is registered with ClinicalTrials.gov, NCT03469804, and is closed to new participants. FINDINGS: 30 patients were screened for eligibility and 17 patients (eight [47%] with classic and nine [53%] with endemic Kaposi's sarcoma) were enrolled between July 2, 2018, and Dec 16, 2019. The median follow-up was 20·4 months (IQR 18·1-24·1). Two (12%) patients had a complete response, ten (59%) had a partial response, and five (29%) had stable disease as the best response within the 6-month treatment timeframe, with a best overall response rate of 71% (95% CI 44-90), meeting the predefined primary outcome (ie, exceeding a response rate of 30%). Treatment-related adverse events occurred in 13 (76%) of 17 patients, including two grade 3 adverse events (one [6%] acute cardiac decompensation and one [6%] granulomatous reaction). Treatment was prematurely discontinued in two (12%) patients due to grade 3 acute reversible cardiac decompensation and grade 2 pancreatitis, and one other patient had a grade 3 granulomatous reaction in mediastinal lymph nodes requiring steroids and methotrexate treatment. There were no serious adverse events or treatment-related deaths. INTERPRETATION: In this prospective trial, which to our knowledge is the first to assess the role of PD-1 blockade in patients with classic and endemic Kaposi's sarcoma, pembrolizumab showed promising anti-tumour activity with an acceptable safety profile. If this result is supported by further studies, treatment with anti-PD-1 could be part of the therapeutic armamentarium for patients with classic and endemic Kaposi's sarcoma. FUNDING: MSD France.

Tuberculosis Diagnosis in HIV-Infected Children: Comparison of the 2012 and 2015 Clinical Case Definitions for Classification of Intrathoracic Tuberculosis Disease.

BACKGROUND: There is no gold standard for tuberculosis diagnosis in children. Clinical Case Definitions for Classification of Intrathoracic Tuberculosis in Children were proposed by international experts in 2012 and updated in 2015. We aimed to compare the 2012 and 2015 Clinical Case Definitions in HIV-infected children with suspected tuberculosis. METHODS: We enrolled HIV-infected children with suspected tuberculosis in Burkina Faso, Cambodia, Cameroon, and Vietnam (ANRS [Agence Nationale de Recherches sur le SIDA et les hépatites virales] 12229 PAANTHER [Pediatric Asian African Network for Tuberculosis and HIV Research] 01 Study). We classified children using the 2012 and 2015 Case Definitions considering as tuberculosis cases those with confirmed tuberculosis and those with probable and unconfirmed tuberculosis in the 2012 and the 2015 classifications, respectively. We assessed agreement between both classifications. RESULTS: Of 438 children enrolled, 197 (45.0%) children were classified as tuberculosis (45 confirmed, 152 probable) using the 2012 Case Definition and 251 (57.3%) were classified as tuberculosis (55 confirmed, 196 unconfirmed) using the 2015 classification. Inter-classification agreement for tuberculosis diagnosis was 364/438, 83.1%, with a kappa statistic of 0.667 (95% confidence interval 0.598-0.736). Of 152 children with probable tuberculosis (2012), 142 (93.4%) were considered as tuberculosis by the 2015 version and 10 (6.6%) as unlikely tuberculosis including 9 with spontaneous clinical improvement. Of 132 possible tuberculosis (2012), 58 (43.9%) were reclassified as tuberculosis (2015). CONCLUSIONS: Agreement between the 2 versions of the Case Definition was substantial but more children were considered as tuberculosis using the 2015 version. Spontaneous symptom resolution reinforces both confidence in the "unlikely" category as being children without tuberculosis and the importance of the clinician's treatment decision in the study.

Comparison of three immunoassays for infliximab trough level monitoring in paediatric inflammatory bowel diseases.

Many clinical studies in paediatric inflammatory bowel diseases (IBD) use infliximab trough level (IFX-TL) and detection of antibody against infliximab (ATI). Hence, comparison of commercially available assays is needed in paediatric samples to assess their reliability and their comparability. We measured IFX-TL and ATI-TL in sera samples of 53 IBD children using three ELISA kits: Lisa-Tracker® Duo Infliximab (Theradiag®), Ridascreen® IFX monitoring (R-Biopharm®) and Promonitor® IFX (Grifols®). Regarding IFX-TL, median values were comparable (p > 0.05), a good statistical correlation has been observed (0.73 ≤ R2 ≤ 0.85) between tested assays and the Bland-Altman analysis found an excellent agreement with a bias estimated between -0.56 and 0.12 and few values outside the 95% limits of agreement. However, qualitative comparison with therapeutic interval classifications showed some discrepancies (30.2%), mainly due to values near thresholds and more often than not with Theradiag® (22.6%). For ATI, because of non-standardized units, the qualitative comparison found a sensibly good agreement (98.1%). These data show a good agreement of IFX-TL and ATI measurement between three marketed ELISA assays with a small bias obtained. Variations in some results can lead to divergent therapeutic interval classifications and prompt us to be cautious in the interpretation of values near therapeutic thresholds.

Performance of 30 commercial SARS-CoV-2 serology assays in testing symptomatic COVID-19 patients.

We report evaluation of 30 assays' (17 rapid tests (RDTs) and 13 automated/manual ELISA/CLIA assay (IAs)) clinical performances with 2594 sera collected from symptomatic patients with positive SARS-CoV-2 rRT-PCR on a respiratory sample, and 1996 pre-epidemic serum samples expected to be negative. Only 4 RDT and 3 IAs fitted both specificity (> 98%) and sensitivity (> 90%) criteria according to French recommendations. Serology may offer valuable information during COVID-19 pandemic, but inconsistent performances observed among the 30 commercial assays evaluated, which underlines the importance of independent evaluation before clinical implementation.

Improvement of HIV-associated neurocognitive disorders after antiretroviral therapy intensification: the Neuro+3 study.

OBJECTIVES: Despite the effectiveness of antiretroviral (ARV) therapy to control HIV infection, HIV-associated neurocognitive disorders (HAND) remain frequent. The Neuro+3 study assessed the cognitive improvement associated with ARV intensification based on increased CNS penetration effectiveness (CPE) scoring ≥+3 and total CPE score ≥9. METHODS: Thirty-one patients, aged 18-65 years, with confirmed diagnosis of HAND and effective ARV therapy were included. The cognitive improvement was measured using Frascati three-stage classification and global deficit score (GDS) after 48 and 96 weeks of ARV intensification. Ultrasensitive HIV-RNA, neopterin, soluble CD14, CCL2, CXCL10, IL6, IL8 and NF-L were measured in plasma and cerebrospinal fluid at Day 0 (baseline), Week 48 (W48) and W96. RESULTS: The intensified ARV was associated with a median (IQR) CPE score increase from 6 (4-7) at baseline to 10 (9-11). From baseline to W96, the median (IQR) GDS decreased from 1.4 (0.8-2.2) to 1.0 (0.6-2.0) (P = 0.009); HAND classification improved from 2 to 1 HIV-associated dementia, 22 to 8 mild neurocognitive disorders, 7 to 17 asymptomatic neurocognitive impairment and 0 to 5 patients without any neurocognitive alterations (P = 0.001). In multivariable linear regression analysis, GDS improvement at W96 was significantly associated with CPE score ≥9 after intensification (P = 0.014), CD4 lymphocyte increase at W48 (P < 0.001) and plasma CXCL10 decrease at W96 (P = 0.001). CONCLUSIONS: In patients with HAND, a significant cognitive improvement was observed after the ARV intensification strategy, with a higher CPE score. Cognitive improvement was more often observed in the case of a switch of two drug classes, arguing for better control of CNS HIV immune activation.

Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 mimicking Kawasaki disease (Kawa-COVID-19): a multicentre cohort.

BACKGROUND: Current data suggest that COVID-19 is less frequent in children, with a milder course. However, over the past weeks, an increase in the number of children presenting to hospitals in the greater Paris region with a phenotype resembling Kawasaki disease (KD) has led to an alert by the French national health authorities. METHODS: Multicentre compilation of patients with KD in Paris region since April 2020, associated with the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ('Kawa-COVID-19'). A historical cohort of 'classical' KD served as a comparator. RESULTS: Sixteen patients were included (sex ratio=1, median age 10 years IQR (4·7 to 12.5)). SARS-CoV-2 was detected in 12 cases (69%), while a further three cases had documented recent contact with a quantitative PCR-positive individual (19%). Cardiac involvement included myocarditis in 44% (n=7). Factors prognostic for the development of severe disease (ie, requiring intensive care, n=7) were age over 5 years and ferritinaemia >1400 µg/L. Only five patients (31%) were successfully treated with a single intravenous immunoglobulin (IVIg) infusion, while 10 patients (62%) required a second line of treatment. The Kawa-COVID-19 cohort differed from a comparator group of 'classical' KD by older age at onset 10 vs 2 years (p<0.0001), lower platelet count (188 vs 383 G/L (p<0.0001)), a higher rate of myocarditis 7/16 vs 3/220 (p=0.0001) and resistance to first IVIg treatment 10/16 vs 45/220 (p=0.004). CONCLUSION: Kawa-COVID-19 likely represents a new systemic inflammatory syndrome temporally associated with SARS-CoV-2 infection in children. Further prospective international studies are necessary to confirm these findings and better understand the pathophysiology of Kawa-COVID-19. Trial registration number NCT02377245.

Assessment of the AQUIOS flow cytometer - An automated sample preparation system for CD4 lymphocyte PanLeucogating enumeration.

BACKGROUND: Flow cytometry has been the approach of choice for enumerating and documenting CD4-cell decline in HIV monitoring. Beckman Coulter has developed a single platform test for CD4+ T-cell lymphocyte count and percentage using PanLeucogating (PLG) technology on the automated AQUIOS flow cytometer (AQUIOS PLG). OBJECTIVES: This study compared the performance of AQUIOS PLG with the Flowcare PLG method and performed a reference interval for comparison with those previously published. METHODS: The study was conducted between November 2014 and March 2015 at 5 different centres located in Canada; Paris, France; Lyon, France; the United States; and South Africa. Two-hundred and forty samples from HIV-positive adult and paediatric patients were used to compare the performances of AQUIOS PLG and Flowcare PLG on a FC500 flow cytometer (Flowcare PLG) in determining CD4+ absolute count and percentage. A reference interval was determined using 155 samples from healthy, non-HIV adults. Workflow was investigated testing 440 samples over 5 days. RESULTS: Mean absolute and relative count bias between AQUIOS PLG and Flowcare PLG was -41 cells/µL and -7.8%. Upward and downward misclassification at various CD4 thresholds was ≤ 2.4% and ≤ 11.1%. The 95% reference interval (2.5th - 97.5th) for the CD4+ count was 453-1534 cells/µL and the percentage was 30.5% - 63.4%. The workflow showed an average number of HIV samples tested as 17.5 per hour or 122.5 per 8-hour shift for one technician, including passing quality controls. CONCLUSION: The AQUIOS PLG merges desirable aspects from conventional flow cytometer systems (high throughput, precision and accuracy, external quality assessment compatibility) with low technical operating skill requirements for automated, single platform systems.

A Treatment-Decision Score for HIV-Infected Children With Suspected Tuberculosis.

BACKGROUND: Diagnosis of tuberculosis should be improved in children infected with HIV to reduce mortality. We developed prediction scores to guide antituberculosis treatment decision in HIV-infected children with suspected tuberculosis. METHODS: HIV-infected children with suspected tuberculosis enrolled in Burkina Faso, Cambodia, Cameroon, and Vietnam (ANRS 12229 PAANTHER 01 Study), underwent clinical assessment, chest radiography, Quantiferon Gold In-Tube (QFT), abdominal ultrasonography, and sample collection for microbiology, including Xpert MTB/RIF (Xpert). We developed 4 tuberculosis diagnostic models using logistic regression: (1) all predictors included, (2) QFT excluded, (3) ultrasonography excluded, and (4) QFT and ultrasonography excluded. We internally validated the models using resampling. We built a score on the basis of the model with the best area under the receiver operating characteristic curve and parsimony. RESULTS: A total of 438 children were enrolled in the study; 251 (57.3%) had tuberculosis, including 55 (12.6%) with culture- or Xpert-confirmed tuberculosis. The final 4 models included Xpert, fever lasting >2 weeks, unremitting cough, hemoptysis and weight loss in the past 4 weeks, contact with a patient with smear-positive tuberculosis, tachycardia, miliary tuberculosis, alveolar opacities, and lymph nodes on the chest radiograph, together with abdominal lymph nodes on the ultrasound and QFT results. The areas under the receiver operating characteristic curves were 0.866, 0.861, 0.850, and 0.846, for models 1, 2, 3, and 4, respectively. The score developed on model 2 had a sensitivity of 88.6% and a specificity of 61.2% for a tuberculosis diagnosis. CONCLUSIONS: Our score had a good diagnostic performance. Used in an algorithm, it should enable prompt treatment decision in children with suspected tuberculosis and a high mortality risk, thus contributing to significant public health benefits.

Cost-effectiveness analysis of strategies using new immunological diagnostic tests of latent tuberculosis infection before TNF-blockers therapy.

Several tests have been proposed to detect latent tuberculosis (LTB). OBJECTIVE: To evaluate the cost-effectiveness of different interferon-gamma release assays based strategies used to screen LTB before tumour necrosis factor (TNF) blockers initiation. METHODS: Consecutive patients with rheumatoid arthritis, spondyloarthritis or Crohn's disease for whom TNF-blockers were considered, were recruited in 15 tertiary care centres. All were screened for LTB with tuberculin skin test (TST), QuantiFERON TB Gold® in tube (QFT) and T-SPOT.TB® (TSpot) on the same day. Cost-minimization and cost-effectiveness analysis, testing 8 screening test combinations, were conducted. Effectiveness was defined as the percentage of LTB treatment avoided and compared with TST alone. Cost were elicited in the payer perspective, included all the costs related to the screening procedure. RESULTS: No tuberculosis reactivation was observed after TNF-blocker initiation. TST followed by QFT if TST was positive was found as the best screening strategy, i.e. the less costly (-54€ compared to reference) and most effective (effectiveness 0.93), resulting in an incremental cost-effectiveness ratio of -192€ per treatment avoided. A probabilistic sensitivity analysis confirmed this result in 72.3% of simulations. CONCLUSION: TST followed by QFT if TST was positive is the most cost-effective strategy in screening for LTB in patients before starting anti-TNF therapy. TRIALREGNO: NCT00811343.

Identifying Cytomegalovirus Complications Using the Quantiferon-CMV Assay After Allogeneic Hematopoietic Stem Cell Transplantation.

Background: A simple test to identify recovery of CMV-specific T-cell immunity following hematopoietic stem cell transplantation (HSCT) could assist clinicians in managing CMV-related complications. Methods: In an observational, multicenter, prospective study of 94 HSCT recipients we evaluated CMV-specific T-cell immunity at baseline, 3, 6, 9, and 12 months after transplant using the Quantiferon-CMV, an enzyme-linked immunosorbent spot assay (ELISpot), and intracellular cytokine staining. Results: At 3 months after HSCT, participants who developed CMV disease (n = 8) compared with CMV reactivation (n = 26) or spontaneous viral control (n = 25) had significantly lower CD8+ T-cell production of interferon-γ (IFN-γ) in response to CMV antigens measured by Quantiferon-CMV (P = .0008). An indeterminate Quantiferon-CMV result had a positive predictive value of 83% and a negative predictive value of 98% for identifying participants at risk of further CMV reactivation. Participants experiencing CMV reactivation compared with patients without CMV reactivation had a reduced proportion of polyfunctional (IFN-γ+/tumor necrosis factor α-positive) CD4+ and CD8+ T cells and a higher proportion of interleukin 2-secreting cells (P = .01 and P = .002, respectively). Conclusions: Quantifying CMV-specific T-cell immunity after HSCT can identify participants at increased risk of clinically relevant CMV-related outcomes.

iNKT and memory B-cell alterations in HHV-8 multicentric Castleman disease.

Human herpesvirus 8 (HHV-8) is the causative agent of Kaposi sarcoma (KS) and multicentric Castleman disease (MCD), a life-threatening, virally induced B-cell lymphoproliferative disorder. HHV-8 is a B-lymphotropic γ-herpesvirus closely related to the Epstein-Barr virus (EBV). Invariant natural killer T (iNKT) cells are innate-like T cells that play a role in antiviral immunity, specifically in controlling viral replication in EBV-infected B cells. Decline of iNKT cells is associated with age or HIV infection, both situations associated with HHV-8-related diseases. We analyzed iNKT cells in both blood (n = 26) and spleen (n = 9) samples from 32 patients with HHV-8 MCD and compared them with patients with KS (n = 24) and healthy donors (n = 29). We determined that both circulating and splenic iNKT cell frequencies were markedly decreased in patients with HHV-8 MCD and were undetectable in 6 of them. Moreover, iNKT cells from patients with HHV-8 MCD displayed a proliferative defect after stimulation with α-galactosylceramide. These iNKT cell alterations were associated with an imbalance in B-cell subsets, including a significant decrease in memory B cells, particularly of marginal zone (MZ) B cells. Coculture experiments revealed that the decrease in iNKT cells contributed to the alterations in the B-cell subset distribution. These observations contribute to a better understanding of the complex interactions between HHV-8 and immune cells that cause HHV-8-related MCD.

Determinants of a Low CD4/CD8 Ratio in HIV-1-Infected Individuals Despite Long-term Viral Suppression.

BACKGROUND: A low CD4/CD8 ratio in human immunodeficiency virus (HIV)-infected individuals despite effective antiretroviral therapy (ART) reflects ongoing immune activation and has been linked to a higher risk of non-AIDS morbidity and mortality. Our aim was to describe the proportion of individuals with a persistent CD4/CD8 ratio <1 despite long-term viral suppression and to determine associated risk factors. METHODS: This cross-sectional study was conducted in 2012 in a single clinical center. HIV type 1 (HIV-1)-infected individuals were eligible if they had a plasma HIV-1 RNA level <50 copies/mL for at least 2 years on a stable ART regimen. Logistic regression was used to identify risk factors for a persistent CD4/CD8 ratio <1. RESULTS: We enrolled 719 individuals with a median CD4/CD8 ratio of 0.8 (interquartile range [IQR], 0.6-1.1), CD4 and CD8 T-cell counts of 565 (IQR, 435-742) cells/µL and 727 (IQR, 530-991) cells/µL respectively, and viral suppression for 5.4 (IQR, 3.3-9.1) years. Cytomegalovirus (CMV) serology was positive in 564 of 645 individuals (87%). Persistent CD4/CD8 ratio <1 was observed in 471 patients (66%). The following factors were independently associated with a CD4/CD8 ratio <1: CMV seropositivity (odds ratio [OR], 1.9 [95% confidence interval {CI}, 1.1-3.1]), ART initiation before 1997 (OR, 1.9 [95% CI, 1.2-3.0] compared with 2002 or later), a lower CD4 T-cell nadir (OR, 0.7 [95% CI, .7-.8] per log2 increment), and shorter duration of viral suppression (OR, 0.6 [95% CI, .5-.8] per 5 years). CONCLUSIONS: Most HIV-infected individuals with long-term viral suppression still had a CD4/CD8 ratio <1. Early initiation and long-term effective ART appear to improve this ratio. CMV coinfection, which represents a potential target for therapeutic intervention, was strongly associated with a persistently suboptimal CD4/CD8 ratio.

Treatment interruption in chronically HIV-infected patients with an ultralow HIV reservoir.

OBJECTIVES: To investigate the potential for combination antiretroviral therapy (cART)-free remission following analytic treatment interruption (ATI) in chronically HIV-infected patients with ultralow cell-associated DNA. METHODS: Pilot study of patients (pts) with plasma viral load (pVL) less than 50 copies/ml for more than 2 years on cART, CD4 above 500 cells/µl, CD4/CD8 above 0.9, CD4 nadir above 300 cells/µl and HIV-DNA below 100 copies/10 peripheral blood mononuclear cells (PBMCs), undergoing treatment interruption. Ultrasensitive pVL, CD4 cell count, triplicate HIV-DNA were measured at D0, W2, W4, and every 4 weeks off-ART until W48 and at W4, W12 and W24 after ART resumption (RxR). RxR occurred in case of pVL rebound above 400 copies/ml or CD4 above 400 cells or HIV-related clinical event. The primary endpoint was the percentage of patients who did not reach RxR criteria at W24. Individuals were to be enrolled in three cohorts of five. Enrolment in cohort 2 began if at least one of five patients from cohort 1 remained in success at W8. Cohort 3 did not start. RESULTS: Ten patients were enrolled, with median (range) CD4 1118 cells/µl (608-1494), CD4/CD8 2.1 (1.4-2.6), HIV-DNA 66 copies/10 PBMC (<66-66) at screening, viral suppression of 4.9 years (2.9-8.3), CD4 nadir 495 cells/µl (330-739). One patient remained off-ART up to W48. Viral rebound occurred in nine of 10 patients at W2 (2 patients), W4 (6 patients) and W12 (one patient). pVL was resuppressed on cART at W4 (8 patients) and W12 (one patient). HIV DNA returned to baseline values within a median of 12 weeks following RxR. CONCLUSION: In a highly selected population of 10 patients with chronic HIV infection, an excellent immune status, durable virological suppression and ultralow reservoir, the success rate of ATI was 10% (95% confidence interval 0.3-44.5%) and nine of 10 patients had prompt rebound of plasma viremia. Resumption of ART led to return to baseline cell-associated total DNA.

Residual immune activation in combined antiretroviral therapy-treated patients with maximally suppressed viremia.

Residual immune activation was studied in 51 HIV-infected individuals, 16 with viral load between 1 and 20 copies/ml and 35 with viral load less than 1 copy/ml, and compared with results in 20 healthy blood donors. Higher T-cell activation and IP-10/CXCL10, MIG/CXCL9 and sCD14 plasma levels persisted in both HIV+ groups. The proportion of activated HLA-DR+ CD4 T cells was inversely correlated with the CD4 nadir and the current CD4 cell counts.