Intérêt du diagnostic biologique de coqueluche lors de malaises graves du nourrisson (à propos de 3 cas)

La coqueluche reste une maladie contagieuse qui depuis la vaccination généralisée touche actuellement les petits nourrissons chez qui elle peut engager le pronostic vital. En effet c'est la première cause infectieuse, et plus précisément bactérienne, de décès chez le petit nourrisson. Le réservoir de cette maladie étant constitué par les jeunes adultes. Nous avons étudié dans un service de pédiatrie générale à Paris, trois cas de malaise graves du nourrisson avec notamment un diagnostic biologique de coqueluche. Ces nourrissons se contaminent auprès de leur parents ou de leur frères ou sœurs dans 40 % des cas environ. Contamination d'autant plus importante que la coqueluche est le plus souvent atypique et pauci-symptomatique chez les adultes. La vaccination anticoqueluche ne confère pas de protection définitive, rendant les adolescents et les adultes à nouveau réceptifs à l'infection et transmetteurs. Une toux de plus de 7 jours chez un adolescent ou un jeune adulte doit faire systématiquement évoquer et rechercher une coqueluche. L'identification en PCR des sécrétions naso-pharyngées devient essentielle pour le diagnostic de coqueluche. La résurgence de la coqueluche est actuellement manifeste chez les nouveau-nés, cibles prioritaires de la prévention. Un rappel obligatoire à 11 ans dans le calendrier vaccinal, le dépistage rigoureux des adultes réinfectés et le traitement par macrolides des personnes recensées dans l'entourage d'un nourrisson infecté, en sont les 3 principales mesures. Par ailleurs, l'introduction de nouveaux rappels vaccinaux à l'âge adulte semble désormais nécessaire, afin de mieux protéger les jeunes nourrissons en modifiant de nouveau l'épidémiologie de la coqueluche.PARIS7-Xavier Bichat (751182101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Plasma Endocan as a Biomarker of Thrombotic Events in COVID-19 Patients

(1) Background: Endocan is a marker of endothelial dysfunction that may be associated with thrombotic events. The aim of the study was to investigate the performance of endocan as a marker of thrombotic events in COVID-19 patients. (2) Methods: We measured endocan in plasma from 79 documented COVID-19 patients classified according to disease severity (from mild to critical). Thrombotic events were recorded. (3) Results: Endocan concentrations at admission were significantly increased according to COVID-19 severity. Levels of endocan were significantly increased in patients experiencing thrombotic events in comparison with those without (16.2 (5.5–26.7) vs. 1.81 (0.71–10.5) ng/mL, p < 0.001). However, endocan concentrations were not different between pulmonary embolism and other thrombotic events. The Receiver Operating Characteristic (ROC) analysis for the identification of thrombotic events showed an area under the ROC curve (AUC) of 0.776 with an optimal threshold at 2.83 ng/mL (93.8% sensitivity and 54.7% specificity). When combining an endocan measurement with D-dimers, the AUC increased to 0.853. When considering both biomarkers, the Kaplan–Meier survival curves showed that the combination of endocan and D-dimers better discriminated patients with thrombotic events than those without. The combination of D-dimers and endocan was independently associated with thrombotic events. (4) Conclusions: Endocan might be a useful and informative biomarker to better identify thrombotic events in COVID-19 patients

Usefulness of Plasma SARS-CoV-2 RNA Quantification by Droplet-based Digital PCR to Monitor Treatment Against COVID-19 in a B-cell Lymphoma Patient

International audienceWe report the case of an HIV-1-infected patient, treated with anti-CD20 monoclonal antibody for a B-cell lymphoma previously treated by autologous stem cell transplant. He suffered from chronic COVID19 and we monitored by plasma SARS-CoV-2 RNA by highly sensitive droplet-based digital PCR technology (ddPCR). Under tocilizumab therapy and despite a first clinical improvement biologically associated with decreasing inflammatory markers, a slight increase of SARS-CoV-2 RNAaemia quantified by ddPCR was highlighted, confirming the absence of viral efficacy of this treatment and predicting the subsequent observed deterioration. As expected, his complete recovery, finally achieved after COVID-19 convalescent plasmatherapy, strictly paralleled plasma SARS-CoV-2 RNA clearance. With these results, we confirmed the interest of SARS-CoV-2 RNAaemia monitoring by ddPCR in COVID-19 patients, particularly during treatment, and firstly showed that this new and specific biomarker could be helpful to select eligible patient for anti-IL6 receptors therapy considering the variable levels of efficacy recently observed with such therapy

Data from: Immune checkpoint inhibitor–related myositis and myocarditis in patients with cancer

Objective: To report the clinicopathological features and outcome of myositis in patients treated with immune checkpoint inhibitors (irMyositis). Methods: We retrospectively analyzed patients diagnosed with irMyositis in tertiary centers in Paris, France, and Berlin, Germany, from January 2015, to July 2017. Main outcomes were clinical manifestations and muscle histology, which included MHC-I, C5b-9, CD3, CD4, CD8, CD20, CD68, PD-1, PD-L1 and PD-L2 immunohistochemical stains. Results: Ten patients with metastatic cancer were included; median age was 73 years (range, 56-87). Median follow-up duration was 48 weeks (range 16-88). Six patients developed myositis during nivolumab therapy, one during pembrolizumab, one during durvalumab, and two during combined nivolumab and ipilimumab. Median delay between immune checkpoint inhibitor (ICI) initiation and myositis onset was 25 days (range, 5-87). Clinical manifestations were dominated by acute or subacute myalgia (8 patients), limb-girdle (7), axial (7) and oculomotor (7) weakness. Four patients had evidence of myocarditis. In all patients, CK levels were elevated (median 2668 U/L, range 1059-16620), while anti-acetylcholine receptor and myositis-associated antibodies were negative. Electrodiagnostic studies showed myopathic process without decrement in all patients. Muscle biopsy constantly showed multifocal necrotic myofibers, sarcolemmal MHC-I and endomysial inflammation, mainly consisting of CD68+ cells expressing PD-L1 and CD8+ cells expressing PD-1. ICI treatment was withdrawn in all patients; nine patients received immunosuppressive therapy, which consistently led to marked clinical improvement. Conclusions: irMyositis presents with remarkably homogeneous and unique clinicopathological features, expanding the nosological spectrum of inflammatory myopathies in patients with cancer. ICI withdrawal and treatment with corticosteroids improve outcome

Platelet activation in critically ill COVID-19 patients

International audienceBackground Microvascular, arterial and venous thrombotic events have been largely described during severe coronavirus disease 19 (COVID-19). However, mechanisms underlying hemostasis dysregulation remain unclear. Methods We explored two independent cross-sectional cohorts to identify soluble markers and gene-expression signatures that discriminated COVID-19 severity and outcomes. Results We found that elevated soluble (s)P-selectin at admission was associated with disease severity. Elevated sP-selectin was predictive of intubation and death (ROC AUC = 0.67, p = 0.028 and AUC = 0.74, p = 0.0047, respectively). An optimal cutoff value was predictive of intubation with 66% negative predictive value (NPV) and 61% positive predictive value (PPV), and of death with 90% NPV and 55% PPV. An unbiased gene set enrichment analysis revealed that critically ill patients had increased expression of genes related to platelet activation. Hierarchical clustering identified ITG2AB , GP1BB , PPBP and SELPLG to be upregulated in a grade-dependent manner. ROC curve analysis for the prediction of intubation was significant for SELPLG and PPBP (AUC = 0.8, p = 0.046 for both). An optimal cutoff value for PBPP was predictive of intubation with 100% NPV and 45% PPV, and for SELPLG with 100% NPV and 50% PPV. Conclusion We provide evidence that platelets contribute to COVID-19 severity. Plasma sP-selectin level was associated with severity and in-hospital mortality. Transcriptional analysis identified PPBP/CXCL7 and SELPLG as biomarkers for intubation. These findings provide additional evidence for platelet activation in driving critical COVID-19. Specific studies evaluating the performance of these biomarkers are required

Immune checkpoint inhibitor-related myositis and myocarditis in patients with cancer

International audienceObjective To report the clinicopathologic features and outcome of myositis in patients treated with immune checkpoint inhibitors (ICIs) (irMyositis). Methods We retrospectively analyzed patients diagnosed with irMyositis in tertiary centers in Paris, France, and Berlin, Germany, from January 2015 to July 2017. The main outcomes were clinical manifestations and muscle histology, which included major histocompatibility complex class I (MHC-I), C5b-9, CD3, CD4, CD8, CD20, CD68, programmed cell death protein 1 (PD-1), programmed cell death 1 ligand 1 (PD-L) 1, and programmed cell death 1 ligand 2 (PD-L2). Results Ten patients with metastatic cancer were included; median age was 73 (range 56–87) years. Median follow-up duration was 48 (range 16–88) weeks. Six patients developed myositis during nivolumab therapy, 1 patient during pembrolizumab, 1 patient during durvalumab, and 2 patients during combined nivolumab and ipilimumab. Median delay between ICI initiation and myositis onset was 25 (range 5–87) days. Clinical manifestations were dominated by acute or subacute myalgia (8 patients) and limb-girdle (7), axial (7), and oculomotor (7) weakness. Four patients had evidence of myocarditis. In all patients, creatine kinase levels were elevated (median 2,668, range 1,059–16,620 U/L), while anti-acetylcholine receptor and myositis-associated antibodies were negative. Electrodiagnostic studies showed myopathic process without decrement in all patients. Muscle biopsy constantly showed multifocal necrotic myofibers, sarcolemmal MHC-I, and endomysial inflammation, consisting mainly of CD68+ cells expressing PD-L1 and CD8+ cells expressing PD-1. ICI treatment was withdrawn in all patients; 9 patients received immunosuppressive therapy, which consistently led to marked clinical improvement. Conclusions irMyositis presents with remarkably homogeneous and unique clinicopathologic features, expanding the nosologic spectrum of inflammatory myopathies in patients with cancer. ICI withdrawal and treatment with corticosteroids improve outcome

Defective activation and regulation of type I interferon immunity is associated with increasing COVID-19 severity

International audienceHost immunity to infection with SARS-CoV-2 is highly variable, dictating diverse clinical outcomes ranging from asymptomatic to severe disease and death. We previously reported reduced type I interferon in severe COVID-19 patients preceded clinical worsening. Further studies identified genetic mutations in loci of the TLR3- or TLR7-dependent interferon-I pathways, or neutralizing interferon-I autoantibodies as risk factors for development of COVID-19 pneumonia. Here we show in patient cohorts with different severities of COVID-19, that baseline plasma interferon α measures differ according to the immunoassay used, timing of sampling, the interferon α subtype measured, and the presence of autoantibodies. We also show a consistently reduced induction of interferon-I proteins in hospitalized COVID-19 patients upon immune stimulation, that is not associated with detectable neutralizing autoantibodies against interferon α or interferon ω. Intracellular proteomic analysis shows increased monocyte numbers in hospitalized COVID-19 patients but impaired interferon-I response after stimulation. We confirm this by ex vivo whole blood stimulation with interferon-I which induces transcriptomic responses associated with inflammation in hospitalized COVID-19 patients, that is not seen in controls or non-hospitalized moderate cases. These results may explain the dichotomy of the poor clinical response to interferon-I based treatments in late stage COVID-19, despite the importance of interferon-I in early acute infection and may guide alternative therapeutic strategies

Defective type I interferon immunity is associated with increasing COVID-19 severity

Host immunity to infection with SARS-CoV-2 is highly variable, dictating diverse clinical outcomes ranging from asymptomatic to severe disease and death. We previously reported that reduced blood type I interferon (IFN-I) in severe COVID-19 patients preceded clinical worsening. These results were supported by studies which identified genetic mutations in loci of the TLR3- or TLR7-dependent IFN-I pathways, or autoantibodies neutralizing IFNα or IFNω, as major risk factors for development of severe and critical COVID-19 pneumonia. Here, we analyzed a range of IFN-I associated responses in patient cohorts with different severities of COVID-19, showing that baseline plasma IFNα measures differed significantly according to the immunoassay used, as well as timing of sampling, the IFNα subtype measured, and the presence of autoantibodies. We then compared immune responses induced by ex vivo stimulation between non-hospitalized moderate cases (n=27) and hospitalized (n=17) adult patients that required oxygen supplementation. This showed a consistently reduced induction of IFN-I proteins in hospitalized COVID-19 patients upon stimulation, that was not associated with detectable neutralizing autoantibodies against IFNα or IFNω. We confirmed the poor induction of IFN-I in an independent patient cohort (n=33), and showed it was more pronounced with severe disease. Intracellular proteomic analysis showed that while monocyte numbers were increased in hospitalized COVID-19 patients, they did not secrete IFN-I in response to stimulation. This was further confirmed by ex vivo whole blood stimulation with IFN-I which induced a transcriptomic response associated with inflammation in hospitalized COVID-19 patients, that was not seen in controls or non-hospitalized moderate cases. These results may explain the dichotomy of the poor clinical response to IFN-I based treatments in late stage COVID-19, despite the critical importance of IFN-I in early acute infection. An improved understanding of such variable responses to treatment may help to identify potential alternative therapeutic strategies

Convalescent plasma therapy for B-cell depleted patients with protracted COVID-19 disease

International audienceAnti-CD20 monoclonal antibodies are widely used for the treatment of hematological malignancies or autoimmune disease but may be responsible for a secondary humoral deficiency. In the context of COVID-19 infection, this may prevent the elicitation of a specific SARS-CoV-2-antibody response. We report a series of 17 consecutive patients with profound B-cell lymphopenia and prolonged COVID-19 symptoms, negative IgG-IgM SARS-CoV-2 serology and a positive RNAemia measured by digital PCR who were treated with four units of COVID-19 convalescent plasma. Within 48 hours following transfusion, all patients except one experienced an amelioration of their clinical symptoms. The inflammatory syndrome abated within a week. Only one patient who needed mechanical ventilation for severe COVID-19 disease died of bacterial pneumonia. SARS-CoV-2 RNAemia decreased to below the sensitivity threshold in 9 out of 9 evaluated patients. Analysis of virus-specific T-cell responses using T-cell enzyme linked immunoSpot (ELISPOT) assay was analyzed before convalescent plasma transfusion in 3 patients. All showed a conserved SARS-CoV-2 T-cell response and poor cross-response to other coronaviruses. No adverse event was reported. In COVID-19 patients unable to mount a specific humoral response to SARS-CoV-2, convalescent plasma with anti-SARS-CoV-2 antibodies appears to be a very promising approach in the context of protracted COVID-19 symptoms