CAR T-cell therapy for central nervous system lymphomas: blood and cerebrospinal fluid biology, and outcomes

Not available.

Identification of natural killer markers associated with fatal outcome in COVID-19 patients

Introduction

Increasing evidence has shown that coronavirus disease 19 (COVID-19) severity is driven by a dysregulated immunological response. Previous studies have demonstrated that natural killer (NK) cell dysfunction underpins severe illness in COVID-19 patients, but have lacked an in-depth analysis of NK cell markers as a driver of death in the most critically ill patients.

Methods

We enrolled 50 non-vaccinated hospitalized patients infected with the initial virus or the alpha variant of SARS-CoV-2 with moderate or severe illness, to evaluate phenotypic and functional features of NK cells.

Results

Here, we show that, consistent with previous studies, evolution NK cells from COVID-19 patients are more activated, with the decreased activation of natural cytotoxicity receptors and impaired cytotoxicity and IFN-γ production, in association with disease regardless of the SARS-CoV-2 strain. Fatality was observed in 6 of 17 patients with severe disease; NK cells from all of these patients displayed a peculiar phenotype of an activated memory-like phenotype associated with massive TNF-α production.

Discussion

These data suggest that fatal COVID-19 infection is driven by an uncoordinated inflammatory response in part mediated by a specific subset of activated NK cells.

Anti-PD-1 immune-related adverse events are associated with high therapeutic antibody fixation on T cells

Immune checkpoint inhibitors (ICI) widely improved the treatment of solid and hematologic malignancies. Yet, a remarkable proportion of patients receiving ICI develop immune related adverse events (irAEs) which are difficult to define as treatment-related. This underlines the need to develop a biomarker to guide irAE diagnosis. We developed a novel flow cytometry assay combining measurement of anti-PD-1 (programmed cell death protein-1) occupancy and evaluation of remaining PD-1 receptor availability with anti-IgG4 PE and anti-PD-1 BV421. We prospectively collected blood and biological fluids samples from patients treated by IgG4 anti-PD-1 therapy (nivolumab or pembrolizumab), with (n=18) or without (n=12) current irAE. We analyzed PD-1+ and IgG4+ staining pattern and MFI values of these parameters on CD4 and CD8 T cells, and IgG4+/PD-1+ MFI ratios are calculated. A higher mean fluorescence intensity IgG4+/PD-1+ ratio was measured on peripheral CD4+ T cells of irAE cases, when compared to controls (p=0.003). ICI-related toxicity is therefore associated with increased therapeutic antibody occupancy of PD-1 receptors on CD4+ T cells. Furthermore, in one case of ICI-related pneumonitis, binding of therapeutic antibody was stronger on lung CD4+ T cell than in blood. In another case of ICI-related encephalitis, the PD-1 receptor occupancy was total on CSF CD4 T cells, but only partial on peripherical CD4 T cells. Our results suggest that flow cytometry monitoring of ICI occupancy can be used in patients treated with monoclonal ICI to guide irAE diagnosis.

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

Methods

Results

Conclusions

Memory CD4+ T-Cell Lymphocytic Angiopathy in Fatal Forms of COVID-19 Pulmonary Infection

The immunopathological pulmonary mechanisms leading to Coronavirus Disease (COVID-19)-related death in adults remain poorly understood. Bronchoalveolar lavage (BAL) and peripheral blood sampling were performed in 74 steroid and non-steroid-treated intensive care unit (ICU) patients (23-75 years; 44 survivors). Peripheral effector SARS-CoV-2-specific T cells were detected in 34/58 cases, mainly directed against the S1 portion of the spike protein. The BAL lymphocytosis consisted of T cells, while the mean CD4/CD8 ratio was 1.80 in non-steroid- treated patients and 1.14 in steroid-treated patients. Moreover, strong BAL SARS-CoV-2 specific T-cell responses were detected in 4/4 surviving and 3/3 non-surviving patients. Serum IFN-γ and IL-6 levels were decreased in steroid-treated patients when compared to non-steroid treated patients. In the lung samples from 3 (1 non-ICU and 2 ICU) additional deceased cases, a lymphocytic memory CD4 T-cell angiopathy colocalizing with SARS-CoV-2 was also observed. Taken together, these data show that disease severity occurs despite strong antiviral CD4 T cell-specific responses migrating to the lung, which could suggest a pathogenic role for perivascular memory CD4 T cells upon fatal COVID-19 pneumonia.

Impact of Anti PD-1 Immunotherapy on HIV Reservoir and Anti-Viral Immune Responses in People Living with HIV and Cancer

The role of immune checkpoints (ICPs) in both anti-HIV T cell exhaustion and HIV reservoir persistence, has suggested that an HIV cure therapeutic strategy could involve ICP blockade. We studied the impact of anti-PD-1 therapy on HIV reservoirs and anti-viral immune responses in people living with HIV and treated for cancer. At several timepoints, we monitored CD4 cell counts, plasma HIV-RNA, cell associated (CA) HIV-DNA, EBV, CMV, HBV, HCV, and HHV-8 viral loads, activation markers, ICP expression and virus-specific T cells. Thirty-two patients were included, with median follow-up of 5 months. The CA HIV-DNA tended to decrease before cycle 2 (p = 0.049). Six patients exhibited a ≥0.5 log₁₀ HIV-DNA decrease at least once. Among those, HIV-DNA became undetectable for 10 months in one patient. Overall, no significant increase in HIV-specific immunity was observed. In contrast, we detected an early increase in CTLA-4 + CD4+ T cells in all patients (p = 0.004) and a greater increase in CTLA-4+ and TIM-3 + CD8+ T cells in patients without HIV-DNA reduction compared to the others (p ≤ 0.03). Our results suggest that ICP replacement compensatory mechanisms might limit the impact of anti-PD-1 monotherapy on HIV reservoirs, and pave the way for combination ICP blockade in HIV cure strategies.

Evolution of anti-SARS-CoV-2 immune response in a cohort of French healthcare workers followed for 7 months

Objectives

We aimed to understand the immune response among healthcare workers (HCWs) following SARS-CoV-2 infection, and to determine the infection prevalence during the first wave of the pandemic among workers in our hospital.

Methods

Determination of the serological status against SARS-CoV-2 (nucleocapsid) was offered to all HCWs. All HCWs with positive SARS-CoV-2 serology were proposed to be included in a longitudinal medical and serological follow-up (anti-spike) for 7 months.

Results

We included 3062 HCWs; 256 (8.4%) were positive for anti-SARS-CoV-2 nucleocapsid IgG. Among them, early decrease in the anti-nucleocapsid antibody index was observed between the first (S1) and second (S2) serology samplings in 208 HCWs (84.2%). The initial anti-nucleocapsid IgG index seemed to be related to the HCWs’ age. Seventy-four HCWs were included in the 7-month cohort study. Among them, 69 (90.5%) had detectable anti-spike IgG after 7 months and 24 (32.4%) reported persistent symptoms consistent with post-acute COVID-19 syndrome diagnosis.

Conclusion

The prevalence of serological positivity among HCWs was 6.7%. Infection should be followed by vaccination because of antibody decrease.

LOX-1-Expressing Immature Neutrophils Identify Critically-Ill COVID-19 Patients at Risk of Thrombotic Complications

Background

Lymphopenia and the neutrophil/lymphocyte ratio may have prognostic value in COVID-19 severity.

Objective

We investigated neutrophil subsets and functions in blood and bronchoalveolar lavage (BAL) of COVID-19 patients on the basis of patients’ clinical characteristics.

Methods

We used a multiparametric cytometry profiling based to mature and immature neutrophil markers in 146 critical or severe COVID-19 patients.

Results

The Discovery study (38 patients, first pandemic wave) showed that 80% of Intensive Care Unit (ICU) patients develop strong myelemia with CD10⁻CD64⁺ immature neutrophils (ImNs). Cellular profiling revealed three distinct neutrophil subsets expressing either the lectin‐like oxidized low‐density lipoprotein receptor‐1 (LOX‐1), the interleukin-3 receptor alpha (CD123), or programmed death-ligand 1 (PD-L1) overrepresented in ICU patients compared to non-ICU patients. The proportion of LOX-1- or CD123-expressing ImNs is positively correlated with clinical severity, cytokine storm (IL-1β, IL-6, IL-8, TNFα), acute respiratory distress syndrome (ARDS), and thrombosis. BALs of patients with ARDS were highly enriched in LOX-1-expressing ImN subsets and in antimicrobial neutrophil factors. A validation study (118 patients, second pandemic wave) confirmed and strengthened the association of the proportion of ImN subsets with disease severity, invasive ventilation, and death. Only high proportions of LOX-1-expressing ImNs remained strongly associated with a high risk of severe thrombosis independently of the plasma antimicrobial neutrophil factors, suggesting an independent association of ImN markers with their functions.

Conclusion

LOX-1-expressing ImNs may help identifying COVID-19 patients at high risk of severity and thrombosis complications.

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013-2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺ <300 cells/mm³ , p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³ ) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.

Nucleocapsid-specific and PD-L1+CXCR3+ CD8 polyfunctional T-cell abundances are associated with survival of critical SARS-CoV2-infected patients

The importance of the adaptive T cell response in the control and resolution of viral infection has been well established. However, the nature of T cell–mediated viral control mechanisms in life-threatening stages of COVID-19 has yet to be determined. The aim of the present study was to determine the function and phenotype of T cell populations associated with survival or death of patients with COVID-19 in intensive care as a result of phenotypic and functional profiling by mass cytometry. Increased frequencies of circulating, polyfunctional CD4⁺CXCR5⁺HLA-DR⁺ stem cell memory T cells (Tscms) and decreased proportions of granzyme B–expressing and perforin-expressing effector memory T cells were detected in recovered and deceased patients, respectively. The higher abundance of polyfunctional PD-L1⁺CXCR3⁺CD8⁺ effector T cells (Teffs), CXCR5⁺HLA-DR⁺ Tscms, and anti-nucleocapsid (anti-NC) cytokine-producing T cells permitted us to differentiate between recovered and deceased patients. The results from a principal component analysis show an imbalance in the T cell compartment that allowed for the separation of recovered and deceased patients. The paucity of circulating PD-L1⁺CXCR3⁺CD8⁺ Teffs and NC-specific CD8⁺ T cells accurately forecasts fatal disease outcome. This study provides insight into the nature of the T cell populations involved in the control of COVID-19 and therefore might impact T cell–based vaccine designs for this infectious disease.

[Immunomonitoring of patients treated with CAR-T cells for hematological malignancy: Guidelines from the CARTi group and the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

CAR-T cells represent a new anti-tumor immunotherapy which has shown its clinical efficacy in B-cell malignancies. The results of clinical trials carried out in this context have shown that certain immunological characteristics of patients before (at the time of apheresis) and after the administration of the treatment, or of the CAR-T cells themselves, are correlated with the response to the treatment or to its toxicity. However, to date, there are no recommendations on the immunological monitoring of patients treated in real life. The objectives of this workshop were to determine, based on data from the literature and the experience of the centers, the immunological analyses to be carried out in patients treated with CAR-T cells. The recommendations relate to the characterization of the patient's immune cells at the time of apheresis, the characterization of the injected CAR-T cells, as well as the monitoring of the CAR-T cells and other parameters of immune reconstitution in the patient after administration of the treatment. Harmonization of practices will allow clinical-biological correlation studies to be carried out in patients treated in real life with the aim of identifying factors predictive of response and toxicity. Such data could have a major medico-economic impact by making it possible to identify the patients who will optimally benefit from these expensive treatments.

IgA dominates the early neutralizing antibody response to SARS-CoV-2

Humoral immune responses are typically characterized by primary IgM antibody responses followed by secondary antibody responses associated with immune memory and composed of IgG, IgA, and IgE. Here, we measured acute humoral responses to SARS-CoV-2, including the frequency of antibody-secreting cells and the presence of SARS-CoV-2-specific neutralizing antibodies in the serum, saliva, and bronchoalveolar fluid of 159 patients with COVID-19. Early SARS-CoV-2-specific humoral responses were dominated by IgA antibodies. Peripheral expansion of IgA plasmablasts with mucosal homing potential was detected shortly after the onset of symptoms and peaked during the third week of the disease. The virus-specific antibody responses included IgG, IgM, and IgA, but IgA contributed to virus neutralization to a greater extent compared with IgG. Specific IgA serum concentrations decreased notably 1 month after the onset of symptoms, but neutralizing IgA remained detectable in saliva for a longer time (days 49 to 73 post-symptoms). These results represent a critical observation given the emerging information as to the types of antibodies associated with optimal protection against reinfection and whether vaccine regimens should consider targeting a potent but potentially short-lived IgA response.

Recurrence and Occurrence of Kaposi's Sarcoma in Patients Living With Human Immunodeficiency Virus (HIV) and on Antiretroviral Therapy, Despite Suppressed HIV Viremia

In 21 cutaneous and/or visceral Kaposi's sarcoma cases, occurring in patients living with human immunodeficiency virus (HIV) who were on antiretroviral therapy with suppressed HIV viremia and high CD4 T cell counts, the efficacy of conventional chemotherapies was limited due to cumulative toxicities, comedications, and a lack of immune improvement.

[Observational study of QuantiFERON® management for ocular tuberculosis diagnosis: Analysis of 244 consecutive tests]

INTRODUCTION

Ocular tuberculosis (TB) diagnosisremains difficult and quantiferon (QFT) contribution needs still yet to be specified, despite its generalization in France. The purpose of this observational study is to assess in which ocular inflammation (OI) presentation QFT is prescribed and to evaluate the added value of new QuantiFERON®-TB Gold Plus (QFT-Plus) test for diagnosis ocular TB diagnosis.

PATIENTS AND METHODS

Monocentric, observational study, carried out in an ophthalmology department over a period of 5 months. Inclusion criteria were defined as an existence of an OI for which a QFT-Plus test was part of the etiological investigations. Of the 316 consecutive files, 72 were excluded (indeterminate test, prescription before anti-TNFα or immunosuppressant initiation, missing data, wrong indication) and 244 were selected and divided into two groups: group one (anterior uveitis/episcleritis, n=129) and group two (intermediate/posterior uveitis/optic neuritis/ocular myositis, n=115). All positive QFT patients underwent an etiological investigation including thoracic imaging.

RESULTS

Forty-five patients, aged 52±12 years, had positive QFT (18.5%), including 18 patients for group 1 and 27 for group 2. Living in TB-endemic area, TB exposure and chest imaging abnormalities were identified in 70%, 27% and 22% of cases, respectively. OI was chronic in 36% of cases (group one, 4/18; group two, 12/27). None of the 18 patients, in group 1, received anti-tuberculosis treatment (ATT) or experienced a relapse during one-year follow-up. Four QFT+ patients, from group 2 (15%) had another associated disease explaining their uveitis. Among the 23 other patients without identified etiology, 13 had at least one relevant ophthalmological signs predictive of TB uveitis (posterior synechiae, retinal vasculitis and/or choroidal granuloma) (59%). Eleven patients received a 6-month ATT trial. Radiological abnormalities and granulomas at angiography were significantly more frequent among treated patients (p=0.03 and 0.001, respectively). A full OI recovery was observed for 8 patients (73%), considered ex-post as ocular TB. Nine patients in group 2 received rifampicin/isoniazid dual therapy for 3 months, but no conclusion could be drawn as to the benefit of such prescription on OI. QFT rate comparison, according to CD4 stimulation by ESAT-6/CFP-10 peptides or by CD4/CD8 co-stimulation, was comparable and found only 4 cases of discrepancy (1.6%). None of these 4 cases had ocular TB diagnosis.

CONCLUSION

Positive QFT frequency among patients consulting for posterior OI remains high. In this study, radiological abnormalities and granulomas at angiography seemed to be more closely related to clinician decision for starting ATT trial in QFT+ patients, which was effective in 73% of cases. QFT-Plus does not seem more relevant than QFT-TB in exploring an OI. Prospective studies are necessary to codify QFT management in the etiological assessment of OI and clearly define ATT trial indications as well as their modalities.

Cell-Mediated Immune Responses to COVID-19 Infection

An unprecedented outbreak of pneumonia caused by a novel coronavirus (CoV), subsequently termed COVID-19 by the World Health Organization, emerged in Wuhan City (China) in December 2019. Despite rigorous containment and quarantine efforts, the incidence of COVID-19 continues to expand, causing explosive outbreaks in more than 160 countries with waves of morbidity and fatality, leading to significant public health problems. In the past 20 years, two additional epidemics caused by CoVs have occurred: severe acute respiratory syndrome-CoV, which has caused a large-scale epidemic in China and 24 other countries; and respiratory syndrome-CoV of the Middle East in Saudi Arabia, which continues to cause sporadic cases. All of these viruses affect the lower respiratory tract and manifest as pneumonia in humans, but the novel SARS-Cov-2 appears to be more contagious and has spread more rapidly worldwide. This mini-review focuses on the cellular immune response to COVID-19 in human subjects, compared to other clinically relevant coronaviruses to evaluate its role in the control of infection and pathogenesis and accelerate the development of a preventive vaccine or immune therapies.

Short Communication: Extremely Severe CD4 Lymphopenia During HIV-1 Primary Infection

We report the case of a patient with a very profound CD4 T cell lymphopenia <20 cells/mm³ in the context of a primary HIV-1 infection, associated with both delayed HIV-specific antibody and CD8 T cell responses. A long-term immune reconstitution was observed after immediate initiation of antiretroviral therapy.

First Report of CD4 Lymphopenia and Defective Neutrophil Functions in a Patient with Amebiasis Associated with CMV Reactivation and Severe Bacterial and Fungal Infections

We report the case of a patient with acute necrotizing colitis due to invasive amebiasis associated with CD4 lymphopenia and impaired neutrophil responses. The course of the disease was characterized by CMV reactivation and severe and recurrent bacterial and fungal infections, which might be related to the decreased CD4 T cell count and the impaired functional capacities of neutrophils, respectively. The clinical outcome was positive with normalization of both CD4 cell count and neutrophil functions.

Non-AIDS-related malignancies: expert consensus review and practical applications from the multidisciplinary CANCERVIH Working Group

Malignancies represent a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients. The introduction of combined antiretroviral therapy has modified the spectrum of malignancies in HIV infection with a decreased incidence of acquired immunodeficiency syndrome (AIDS) malignancies such as Kaposi's sarcoma and non-Hodgkin's lymphoma due to partial immune recovery and an increase in non-AIDS-defining malignancies due to prolonged survival. Management of HIV-infected patients with cancer requires a multidisciplinary approach, involving both oncologists and HIV physicians to optimally manage both diseases and drug interactions between anticancer and anti-HIV drugs. The French CANCERVIH group presents here a review and an experience of managing non-AIDS malignancies in HIV-infected individuals.

Soluble biomarkers of immune activation and inflammation in HIV infection: impact of 2 years of effective first-line combination antiretroviral therapy

OBJECTIVES

The aim of the study was to assess the impact of rapid and sustained viral control produced by combination antiretroviral therapy (cART) on HIV-associated immune activation and inflammation.

METHODS

In this longitudinal observational study, we examined changes in interleukin-6 (IL-6), interferon-γ-inducible protein-10 (IP-10), monokine induced by interferon-γ (MIG) and soluble CD14 (sCD14) levels during 2 years of effective first-line cART. Biomarker levels before and after cART were compared with those observed in healthy subjects, using the Wilcoxon signed rank test. Elevated biomarker levels were defined with respect to values for healthy subject (mean + 2 standard deviations). Factors associated with persistently elevated biomarker levels after 2 years of cART were identified by logistic regression.

RESULTS

We included in the study 139 patients with a median HIV-1 RNA level of 4.8 log10 HIV-1 RNA copies/mL and a median CD4 cell count of 294 cells/μL at cART initiation [day 0 (D0)]. At D0, all biomarker levels were higher than in healthy subjects (P < 0.05). After 2 years of cART, IL-6, IP-10 and MIG levels fell significantly, by a median of 0.54, 420 and 1107 pg/mL, respectively (all P < 0.001), and were no longer elevated in > 75% of patients. In contrast, sCD14 levels did not change significantly (0.18 × 10(6)  pg/mL; P = 0.102) and remained elevated. Older age was associated with elevated levels of IP-10 [odds ratio (OR) 1.60 per 10 years older; P = 0.047] and MIG (OR 1.92 per 10 years older; P = 0.007) after 2 years of cART.

CONCLUSIONS

The rapid and sustained viral suppression produced by first-line cART reduced IL-6, IP-10 and MIG to normal levels, while sCD14, a marker of monocyte activation, remained elevated. High levels of IP-10 and MIG tended to persist in older patients.

The HIV-1 antisense protein (ASP) induces CD8 T cell responses during chronic infection

Background

CD8+ T cells recognize HIV-1 epitopes translated from a gene’s primary reading frame (F1) and any one of its five alternative reading frames (ARFs) in the forward (F2, F3) or reverse (R1-3) directions. The 3’ end of HIV-1’s proviral coding strand contains a conserved sequence that is directly overlapping but antiparallel to the env gene (ARF R2) and encodes for a putative antisense HIV-1 protein called ASP. ASP expression has been demonstrated in vitro using HIV-transfected cell lines or infected cells. Although antibodies to ASP were previously detected in patient sera, T cell recognition of ASP-derived epitopes has not been evaluated. We therefore investigated the ex vivo and in vitro induction of ASP-specific T cell responses as a measure of immune recognition and protein expression during HIV-1 infection.

Results

A panel of overlapping peptides was initially designed from the full-length ASP sequence to perform a global assessment of T cell responses. Recognition of ASP-derived antigens was evaluated in an IFN-γELISpot assay using PBMCs from HIV-1 seropositive and seronegative individuals. Eight of 25 patients had positive responses to ASP antigens and none of the seronegative donors responded. As a complimentary approach, a second set of antigens was designed using HLA-I binding motifs and affinities. Two ASP-derived peptides with high predicted binding affinities for HLA-A*02 (ASP-YL9) and HLA-B*07 (ASP-TL10) were tested using PBMCs from HIV-1 seropositive and seronegative individuals who expressed the matching HLA-I-restricting allele. We found that HLA-I-restricted ASP peptides were only recognized by CD8+ T cells from patients with the relevant HLA-I and did not induce responses in any of the seronegative donors or patients who do not express the restrictive HLA alleles. Further, ASP-YL9-specific CD8+ T cells had functional profiles that were similar to a previously described HLA-A*02-restricted epitope (Gag-SL9). Specific recognition of ASP-YL9 by CD8+ T cells was also demonstrated by tetramer staining using cells from an HLA-A*02 HIV-infected patient.

Conclusion

Our results provide the first description of CD8+ T cell-mediated immune responses to ASP in HIV-1-infected patients, demonstrating that ASP is expressed during infection. Our identification of epitopes within ASP has implications for designing HIV vaccines.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0135-y) contains supplementary material, which is available to authorized users.

Low titers of serum antibodies inhibiting hemagglutination predict fatal fulminant influenza A(H1N1) 2009 infection

RATIONALE

The biology of fatal pandemic influenza infection remains undefined.

OBJECTIVES

To characterize the virologic and immune parameters associated with severity or death in patients who required mechanical ventilation for A(H1N1) 2009 pneumonia of various degrees of severity during the two waves of the 2009-2011 pandemic in Paris, France.

METHODS

This multicenter study included 34 unvaccinated patients with very severe or fatal confirmed influenza A(H1N1) infections. It analyzed plasma A(H1N1) 2009 reverse-transcriptase polymerase chain reaction, hemagglutinin 222G viral mutation, and humoral and cellular immune responses to the virus, assessed in hemagglutination inhibition (HI), microneutralization, ELISA, lymphoproliferative, ELISpot IFN-γ, and cytokine and chemokine assays.

MEASUREMENTS AND MAIN RESULTS

The patients' median age was 35 years. Influenza A(H1N1) 2009 viremia was detected in 4 of 34 cases, and a 222G hemagglutinin mutation in 7 of 17 cases, all of them with sequential organ failure assessment greater than or equal to 8. HI antibodies were detectable in 19 of 26 survivors and undetectable in all six fatal fulminant cases. ELISA and microneutralization titers were concordant. B-cell immunophenotyping and plasma levels of immunoglobulin classes did not differ between patients who survived and died. After immune complex dissociation, influenza ELISA serology became strongly positive in the bronchoalveolar lavage of the two fatal cases tested. H1N1-specific T-cell responses in lymphoproliferative and IFN-γ assays were detectable in survivors' peripheral blood, and lymphoproliferative assays were negative in the three fatal cases tested. Plasma levels of IL-6 and IL-10 were high in fatal cases and correlated with severity. Finally, a negative HI serology 4 days after the onset of influenza symptoms predicted death from fulminant influenza (P = 0.04).

CONCLUSIONS

Early negative A(H1N1) 2009 HI serology can predict death from influenza. This negative serology in fatal cases in young adults reflects the trapping of anti-H1N1 antibodies in immune complexes in the lungs, associated with poor specific helper T-cell response. Clinical trial registered with www.clinicaltrials.gov (NCT 01089400).

Pulmonary manifestations of human herpesvirus-8 during HIV infection

Human herpesvirus (HHV)-8 is an oncogenic gamma herpesvirus that was first described in 1994 in Kaposi sarcoma lesions. HHV-8 is involved in the pathophysiological features of multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL), both rare B-cell lymphoproliferative diseases. HHV-8-related tumours occur almost exclusively in immunocompromised patients, mostly those with HIV infection. Combined antiretroviral therapies have reduced the incidence of Kaposi sarcoma but not MCD and PEL. HHV-8-related diseases frequently exhibit pulmonary involvement, which may indicate the disease. Kaposi sarcoma in the lung is often asymptomatic but may require specific therapy. It mostly shows cutaneous or mucosal involvement. Patients with typical MCD present fever and lymphadenopathy associated with interstitial lung disease without opportunistic infection. Specific treatment may be urgent. PEL provokes a febrile, lymphocytic-exudative pleural effusion, without a pleural mass on computed tomography scan. Rapid diagnosis prevents unnecessary examinations and leads to specific, rapid treatment. Therapy is complex, combining antiretroviral therapy and chemotherapy.

Performance of Quantiferon(®) for the diagnosis TB

OBJECTIVES

The aim of the study was to evaluate the performance of Quantiferon Gold-In-Tube(®) (QFN) for the diagnosis of tuberculosis (TB) during hospitalization in an infectious diseases department.

PATIENTS AND METHODS

QFN was performed in 245 patients recently hospitalized for suspected TB. Subsets of patients underwent tuberculin skin tests (TST), and microbiological cultures were performed.

RESULT

TB was diagnosed in 57 (23%) patients: pulmonary in 23 (40%), extrapulmonary in 16 (28%), and disseminated in 18 (32%). Seventeen (30%) of these TB patients were immunocompromised, including 12 with HIV infection. The sensitivity of QFN was 74%, its specificity 56%, its positive predictive value 43% and negative predictive value (NPV) 92%. The sensitivity was similar in pulmonary and extrapulmonary TB but lower in disseminated TB, although not significantly so. The sensitivity was also lower (P=0.04) in immunocompromised patients. The specificity was lower in migrants than in native French patients (P=0.01), and lower in patients with a history of TB than in those without (P<0.001). Finally, combining culture with QFN significantly increased the sensitivity (P=0.008), and produced a higher NPV, as for the combination with TST, but not significantly different than with QFN alone.

CONCLUSION

The performance of QFN was weak in this context, especially in subgroups at high risk for latent TB. However, combined negative results of QFN or TST and culture could be useful to rule out active TB.

Old age and anti-cytomegalovirus immunity are associated with altered T-cell reconstitution in HIV-1-infected patients

OBJECTIVE AND DESIGN

Increasing evidence supports a parallel between HIV-1 infection and immune aging, which is particularly apparent with common changes in naive versus memory T-cell proportions. Here, we aimed at refining the value of common T-cell-associated markers of immunosenescence during HIV disease progression or aging, and at exploring further the impact in this context of old age as well as cytomegalovirus (CMV) co-infection, which is predominant in HIV-1-infected individuals.

METHODS

Frequencies of naive or CD57(+) memory T cells as well as the magnitude of CMV-pp65 T cells were measured in HIV-1-infected patients grouped according to disease progression status, treatment and age.

RESULTS

Our results indicate that the decline in naive T-cell levels rather than the accumulation of CD57(+) senescent T cells identifies best the premature development of an immunosenescence phenotype with HIV disease progression. Moreover, advanced age or mounting of strong CMV-specific responses impact independently on CD4(+) T-cell counts and recovery with antiretroviral therapy.

CONCLUSIONS

The present findings indicate that HIV-1 infection amplifies the effect of age on naive T-cell levels, and highlight the constraint on the capacity of treated patients to reconstitute their CD4(+) T-cell compartment due to age and CMV co-infection.

CTL escape mediated by proteasomal destruction of an HIV-1 cryptic epitope

Cytotoxic CD8+ T cells (CTLs) play a critical role in controlling viral infections. HIV-infected individuals develop CTL responses against epitopes derived from viral proteins, but also against cryptic epitopes encoded by viral alternative reading frames (ARF). We studied here the mechanisms of HIV-1 escape from CTLs targeting one such cryptic epitope, Q9VF, encoded by an HIVgag ARF and presented by HLA-B*07. Using PBMCs of HIV-infected patients, we first cloned and sequenced proviral DNA encoding for Q9VF. We identified several polymorphisms with a minority of proviruses encoding at position 5 an aspartic acid (Q9VF/5D) and a majority encoding an asparagine (Q9VF/5N). We compared the prevalence of each variant in PBMCs of HLA-B*07+ and HLA-B*07- patients. Proviruses encoding Q9VF/5D were significantly less represented in HLA-B*07+ than in HLA-B*07- patients, suggesting that Q9FV/5D encoding viruses might be under selective pressure in HLA-B*07+ individuals. We thus analyzed ex vivo CTL responses directed against Q9VF/5D and Q9VF/5N. Around 16% of HLA-B*07+ patients exhibited CTL responses targeting Q9VF epitopes. The frequency and the magnitude of CTL responses induced with Q9VF/5D or Q9VF/5N peptides were almost equal indicating a possible cross-reactivity of the same CTLs on the two peptides. We then dissected the cellular mechanisms involved in the presentation of Q9VF variants. As expected, cells infected with HIV strains encoding for Q9VF/5D were recognized by Q9VF/5D-specific CTLs. In contrast, Q9VF/5N-encoding strains were neither recognized by Q9VF/5N- nor by Q9VF/5D-specific CTLs. Using in vitro proteasomal digestions and MS/MS analysis, we demonstrate that the 5N variation introduces a strong proteasomal cleavage site within the epitope, leading to a dramatic reduction of Q9VF epitope production. Our results strongly suggest that HIV-1 escapes CTL surveillance by introducing mutations leading to HIV ARF-epitope destruction by proteasomes.

Management of travelers with fever and exanthema, notably dengue and chikungunya infections

Febrile exanthema frequently presents as an acute condition in travelers. Sixty-two travelers who presented with febrile exanthema were prospectively included over a 20-month period. Diagnostic tests were performed according to clinical presentation and risk exposures. Symptoms occurred after return in 56% of these travelers, and the median interval between return and symptom onset was 2 days. The 3 main travel destinations were the Indian Ocean (35%), Africa (21%), and Asia (18%). The 3 main etiologies were chikungunya (35%), dengue (26%), and African tick bite fever (ATBF) (10%). Travel to the Indian Ocean and South Africa was significantly associated with respectively chikungunya and ATBF. Arthralgias were significantly more frequent in chikungunya than in dengue, whereas leucopenia, neutropenia, and thrombopenia were significantly more frequent in dengue. Travelers presenting with febrile exanthema should therefore be screened for arboviral infections according to the area visited.

Thoracic Radiographic and CT Findings of Multicentric Castleman Disease in HIV-infected Patients

Multicentric HIV-related Castleman disease (MCD) is a rare and severe disorder of lymphoid tissue inducing high-grade fever, hepatosplenomegaly, and diffuse peripheral lymphadenopathy. During clinical exacerbations, bilateral interstitial pneumonia may occur. In this pictorial essay, we describe different thoracic imaging of MCD, with particular emphasis on computed tomography findings, in 13 HIV-infected patients with histologically proved MCD.

Telemetric Monitoring of Pulmonary Function After Allogeneic Hematopoietic Stem Cell Transplantation

BACKGROUND

Late-onset noninfectious pulmonary complications (LONIPC) are both frequent and severe after allogeneic hematopoietic stem cell transplantation (HSCT). The high mortality rate (40-80%) may be related to delayed diagnosis. We assessed the use of telemetric home surveillance of pulmonary function for early diagnosis of LONIPC in transplant recipients.

METHODS

This prospective study monitored pulmonary function in 37 allogeneic HSCT recipients. About 3 months after HSCT, they received a portable spirometer that measured forced vital capacity, forced expiratory volume per second, and midexpiratory flow 25-75 (MEF25-75). Data were transmitted twice weekly by telephone. Conventional plethysmography confirmed any significant deterioration (>20%).

RESULTS

Thirteen episodes of spirometric deterioration were detected by telemetry in 11 patients during a median 17-month (4-41) follow-up period after transplantation. In these cases, examinations including spirometry, high-resolution thoracic computed tomography and bronchoalveolar lavage diagnosed LONIPC in eight episodes in seven patients (cumulative incidence 23.4%, SE 0.08, at month 24 after transplant): bronchiolitis obliterans (BO, n=3), interstitial pneumonia (IP, n=4), or both BO and IP (n=1). Five episodes improved and three were stabilized with increased immunosuppressive therapy. At the last follow-up, of the seven patients with LONIPC, one successfully stopped immunosuppressive therapy, two were receiving low-dose mycophenolate mofetil, and four were receiving low-dose corticosteroid therapy. There were no cases of respiratory failure and no patient died from LONIPC.

CONCLUSION

Telemetric home monitoring of pulmonary function is a useful procedure for early diagnosis of LONIPC before clinical pulmonary symptoms and may improve outcome after allogeneic HSCT.

Bioterrorism: management of major biological agents

Bioterrorism is defined by the intentional or threatened of microorganisms or toxins derived from living organisms to cause death or diseases in humans, animals or plants on which we depend. The other major point is to generate fear in the population. More than 180 pathogens have been reported to be potential agents for bioterrorism. The following is an overview of several agents that could be involved in a biological attack.

Pulmonary manifestations of multicentric Castleman's disease in HIV infection: a clinical, biological and radiological study

The aim of the present study was to report clinical, radiological and bronchoalveolar lavage (BAL) findings in patients with pulmonary manifestations of HIV-associated multicentric Castleman's disease (MCD). This was a retrospective study of 12 patients with histologically proven MCD. Clinical manifestations were as follows: dyspnoea (nine out of 12 cases), cough (n = 10), bilateral crackles (n = 10), together with high fever, malaise, peripheral lymphadenopathy (n = 12), and hepatosplenomegaly (n = 10). Two patients developed acute respiratory distress syndrome. Chest radiographs and computed tomography scans showed reticular (n = 7) and/or nodular (n = 7) interstitial patterns, with mediastinal lymphadenopathy (n = 9), and bilateral pleural effusion (n = 3). Fibreoptic endoscopy was normal in all cases. BAL analysis showed hypercellularity (n = 6) and/or lymphocytosis (n = 6), and human herpesvirus-8 DNA was detected in two out of two cases. Specific stains and cultures for pathogens were negative. All patients received etoposide and/or vinblastine, and improved after 2-4 days. Relapses were frequent (50 attacks in 12 patients). Six patients developed a non-Hodgkin's lymphoma, and five died. In conclusion, the pulmonary manifestation of HIV-related multicentric Castleman's disease is an acute reticulo-nodular interstitial pneumonitis, associated with severe systemic symptoms and peripheral lymphadenopathy. In bronchoalveolar lavage fluid, cellularity is not specific and human herpesvirus-8 DNA is detected. The clinical course is specific due to a rapid onset and regression, frequent relapses and a high occurrence of non-Hodgkin's lymphoma.

[Emerging or re-emerging infections that can be used for bioterrorism]

USED FOR WARFARE: Bioterrorism is a perfectly foreseeable eventuality. It is defined by the international use, or menace of use, of living organisms whatever their nature, or of substances derived from these organisms, aimed at provoking a disease or the death of human beings, animals or plants. UPDATED COUNTERACTING STRATEGIES: More than 180 infectious agents could be used for terrorist ends. The recent events in the dawn of this twenty-first century have reactivated and notably updated the strategies to counteract such an event. Clinical and therapeutic guidelines have been circulated in many countries. INFECTIONS THAT REQUIRE RECOGNITION: The role of practitioners in the rapid recognition of bioterrorism-related infections is crucial. Hence, updated knowledge on these potentially emerging or reemerging infections is required.

[Bioterrorism with brucellosis]

A CONTAMINATING SPRAY: Brucellosis is a zoonosis due to a bacteria of the Brucella. B. melitensis species and is the principle agent of human brucellosis. The interest of Brucella as a biological weapon resides in the fact that transmission through a spray is possible, as has been reported with human contamination during abortion of infected animals or bacterial spraying in laboratories. The bacteria is highly contagious. It is suggested that 10 to 100 bacteria would be sufficient to produce a contaminating spray for humans. THE MENACE: In 1954, B. suis was the first infectious agent used as a biological weapon in the United States. Several other countries have been suspected of studying the agent as a biological weapon, but to date, no use of Brucella in a bioterrorist attack has been reported. THE EXTENT OF RISK: Brucella, and notably B. melitensis and B. suis, are considered as agents unlikely to be used as biological weapons: their incubation is long, the majority of infections are asymptomatic and mortality is low. However, the morbidity of this agent should not be underrated since it leads to chronic and disabling pathologies.

[Severe acute respiratory syndrome: a singular epidemic of viral pneumonia]

INFECTIOUS AGENT: The severe acute respiratory syndrome (SARS) is a febrile pneumonia initially observed in China at the end of 2002. The infectious agent has rapidly been identified as a new coronavirus, baptised SARS-associated coronavirus (CoV-SARS). Transmission is inter-human, via respiratory particles mainly.

CLINICAL PRESENTATION AND TREATMENT

The clinical presentation is highly variable, from a mild fever to an acute respiratory distress syndrome. There is no specific treatment. Ribavirin associated with steroids have been used with success in numerous cases.

EPIDEMIOLOGY

During the first half of 2003, the spreading of the virus has been very fast, with a pandemic mode of evolution. More than 8,000 people were infected and 774 died. The reservoir of the virus, which may be animal, is still unknown. The epidemic seems to be controlled, but sporadic or epidemic re-emergences may occur and have been observed in China during January 2004.

[Q fever, a potential biowarfare agent]

SEVERAL POSSIBLE METHODS OF TRANSFUSION: Q fever is a zoonosis due to Coxiella burnetii. Its interest as a potential biowarfare agent is in its possible transmission by inhalation of sprayed particles. This form of transmission would probably be used: the inhalation of 1 to 10 bacteria could provoke the development of an infection in humans. Another possible method of transmission in the context of a terrorist act would be the intentional introduction of the bacteria into foodstuff. A DISABLING WEAPON: However, C. burnetii has never been used as a biological weapon. The probability that this germ could be used is very low: indeed, the incubation of Q fever is very long, and the majority of the infections is asymptomatic and mortality is low. In fact C. burnetii would more likely be used as a disabling weapon.

[Severe acute respiratory syndrome: update]

Propos et points forts. – Le syndrome respiratoire aigu sévère (SRAS) a récemment été reconnu comme étant associé à une infection virale émergente, hautement contagieuse et pouvant être mortelle.

Actualités. – À fin juin 2003, plus de 8500 cas d’infections humaines et 800 décès ont été rapportés dans 30 pays. L’agent responsable de cette infection a été identifié comme étant un nouveau coronavirus. La présentation clinique, les anomalies biologiques et radiologiques, ainsi que l’évolution et le traitement des patients infectés par ce virus sont décrits dans cet article.

Perspectives et projets. – La recherche de thérapeutiques efficaces et de vaccins est en cours d’évaluation.