Increased SARS-CoV-2 reactive low avidity T cells producing inflammatory cytokines in pediatric post-acute COVID-19 sequelae (PASC).

BACKGROUND: A proportion of the convalescent SARS-CoV-2 pediatric population presents nonspecific symptoms, mental health problems, and a reduction in quality of life similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID-19 symptomatic. However, data regarding its clinical manifestation and immune mechanisms are currently scarce. METHODS: In this study, we perform a comprehensive clinical and immunological profiling of 17 convalescent COVID-19 children with post-acute COVID-19 sequelae (PASC) manifestation and 13 convalescent children without PASC manifestation. A detailed medical history, blood and instrumental tests, and physical examination were obtained from all patients. SARS-CoV-2 reactive T-cell response was analyzed via multiparametric flow cytometry and the humoral immunity was addressed via pseudovirus neutralization and ELISA assay. RESULTS: The most common PASC symptoms were shortness of breath/exercise intolerance, paresthesia, smell/taste disturbance, chest pain, dyspnea, headache, and lack of concentration. Blood count and clinical chemistry showed no statistical differences among the study groups. We detected higher frequencies of spike (S) reactive CD4+ and CD8+ T cells among the PASC study group, characterized by TNFα and IFNγ production and low functional avidity. CRP levels are positively correlated with IFNγ producing reactive CD8+ T cells. CONCLUSIONS: Our data might indicate a possible involvement of a persistent cellular inflammatory response triggered by SARS-CoV-2 in the development of the observed sequelae in pediatric PASC. These results may have implications on future therapeutic and prevention strategies.

Fading SARS-CoV-2 humoral VOC cross-reactivity and sustained cellular immunity in convalescent children and adolescents.

Cross-reactive cellular and humoral immunity can substantially contribute to antiviral defense against SARS-CoV-2 variants of concern (VOC). While the adult SARS-CoV-2 cellular and humoral immunity and its cross-recognition potential against VOC is broadly analyzed, similar data regarding the pediatric population are missing. In this study, we perform an analysis of the humoral and cellular SARS-CoV-2 response immune of 32 convalescent COVID-19 children (children), 27 convalescent vaccinated adults(C + V+) and 7 unvaccinated convalescent adults (C + V-). Similarly to adults, a significant reduction of cross-reactive neutralizing capacity against delta and omicron VOC was observed 6 months after SARS-CoV-2 infection. While SAR-CoV-2 neutralizing capacity was comparable among children and C + V- against all VOC, children demonstrated as expected an inferior humoral response when compared to C + V+. Nevertheless, children generated SARS-CoV-2 reactive T cells with broad cross-recognition potential. When compared to V + C+, children presented even comparable frequencies of WT-reactive CD4 + and CD8 + T cells with high avidity and functionality. Taking into consideration the limitations of study - unknown disease onset for 53% of the asymptomatic pediatric subjects, serological detection of SARS-CoV-2 infection-, our results suggest that following SARS-CoV-2 infection children generate a humoral SARS-CoV-2 response with neutralizing potential comparable to unvaccinated COVID-19 convalescent adults as well a sustained SARS-CoV-2 cellular response cross-reactive to VOC.

Dexamethasone Does not Compensate for Local Anesthetic Cytotoxic Effects on Tenocytes: Morphine or Morphine Plus Dexamethasone May Be a Safe Alternative.

Purpose: The purposes of this in vitro study were to investigate whether the addition of dexamethasone can compensate for any cytotoxic effects of the amide-type local anesthetics (LA) bupivacaine and ropivacaine and whether morphine and morphine-6-glucuronide (M6G) may be a safe alternative for peritendinous application. Methods: Biopsies of human biceps tendons (n = 6) were dissected and cultivated. Cells were characterized by the expression for tenocyte markers, collagen I, biglycan, tenascin C, scleraxis, and RUNX via reverse transcriptase-polymerase chain reaction and immunohistochemistry. Tenocytes were incubated with bupivacaine, ropivacaine, morphine, M6G, or a saline control with and without addition of dexamethasone for 15, 60, or 240 min. Cell viability was determined by quantifying the presence of adenosine-triphosphate. Results: Significant time-dependent cytotoxic effects were observed for LA after all exposure times. After 15, 60, and 240 minutes, cell viability decreased to 81.1%, 49.4% and 0% (P < .001) for bupivacaine and to 81.4%, 69.6%, and 9.3% (P < .001) for ropivacaine compared to saline control. Dexamethasone did not compensate for these cytotoxic effects. Cell viability was not affected after 15, 60-min exposures to morphine and M6G but decreased significantly (P < .001) after 240 minutes compared to saline control. However, in combination with dexamethasone, tenocyte viability was significantly increased at all times for morphine (P < .01) and at 15 and 60 minutes for M6G (P < .01). Conclusions: The results showed that amide-type LA have a time-dependent cytotoxic effect on human tenocytes in vitro, which could not be compensated for by dexamethasone, whereas morphine and M6G had no cytotoxic effects on tenocytes after 15 and 60 minutes. The addition of dexamethasone to morphine and M6G had a positive effect on viability, which increased significantly compared to the opioids. Clinical Relevance: It is known that amide-type local anesthetics used for local joint analgesia have chondrotoxic side-effects. The combined application of morphine and dexamethasone may be a safe alternative.

Biomarkers for Malignant Pleural Mesothelioma-A Novel View on Inflammation.

Malignant pleural mesothelioma (MPM) is an aggressive disease with limited treatment response and devastating prognosis. Exposure to asbestos and chronic inflammation are acknowledged as main risk factors. Since immune therapy evolved as a promising novel treatment modality, we want to reevaluate and summarize the role of the inflammatory system in MPM. This review focuses on local tumor associated inflammation on the one hand and systemic inflammatory markers, and their impact on MPM outcome, on the other hand. Identification of new biomarkers helps to select optimal patient tailored therapy, avoid ineffective treatment with its related side effects and consequently improves patient's outcome in this rare disease. Additionally, a better understanding of the tumor promoting and tumor suppressing inflammatory processes, influencing MPM pathogenesis and progression, might also reveal possible new targets for MPM treatment. After reviewing the currently available literature and according to our own research, it is concluded that the suppression of the specific immune system and the activation of its innate counterpart are crucial drivers of MPM aggressiveness translating to poor patient outcome.

Tumour cell PD-L1 expression is prognostic in patients with malignant pleural effusion: the impact of C-reactive protein and immune-checkpoint inhibition.

Malignant pleural effusion (MPE) confers dismal prognosis and has limited treatment options. While immune-checkpoint inhibition (ICI) proved clinical efficacy in a variety of malignancies, data on the prognostic role of PD-L1 in MPE is scarce. We retrospectively studied PD-L1 tumour proportion score and Ki-67 index in pleural biopsies or cytologies from 123 patients (69 lung cancer, 25 mesothelioma, and 29 extrathoracic primary malignancies). Additionally, the impact of C-reactive protein (CRP) and platelet count was also analysed. Median overall survival (OS) after MPE diagnosis was 9 months. Patients with PD-L1 positive tumours (≥1%) had significantly shorter OS than patients with negative PD-L1 status (p = 0.031). CRP and Ki-67 index were also prognostic and remained independent prognosticators after multivariate analysis. Interestingly, Ki-67 index and CRP influenced the prognostic power of PD-L1. Finally, patients receiving ICI tended to have a longer median OS and CRP - but not PD-L1 - was a significant prognosticator in this subgroup. In summary, histological and circulating biomarkers should also be taken into account as potential biomarkers in ICI therapy and they may have an impact on the prognostic power of PD-L1. Our findings might help personalizing immune-checkpoint inhibition for patients with MPE and warrant further prospective validation.

A novel mutation of the folliculin gene causing Birt-Hogg-Dubé syndrome as rare cause for secondary pneumothorax.

The Birt-Hogg-Dubé syndrome is an orphan genetic disease characterized by the development of renal neoplasms, fibrofolliculomas, pulmonary cysts and spontaneous pneumothoraces. Here, we report on the case of a 21-year-old man presenting with a primary event of a persistent spontaneous pneumothorax. Computed tomography images and a positive family history for pneumothoraces led to the suspicion of Birt-Hogg-Dubé syndrome. Genetic testing then confirmed the suspected clinical diagnosis, however with a mutation that has not yet been reported.

Opioids as an alternative to amide-type local anaesthetics for intra-articular application.

PURPOSE: Recently, the safety profile of local anaesthetics in intra-articular use became into focus of investigation. Opioid drugs have a different mode of action and may be a safe and potent alternative for intra-articular application. The purpose of this in vitro study is to provide evidence for significant chondrotoxicity of amide-type local anaesthetics even after short-term application on human chondrocytes and to demonstrate the absence of such negative effects for opioids [morphine, morphine-6-glucuronide (M6G)]. METHOD: Visually intact cartilage explants of human, mainly osteoarthritic joints (n = 9), were harvested and cultivated in monolayer for expansion and transferred into alginate bead. The beads were incubated for increasing incubation times (15 min, 1 and 4 h) in decreasing concentrations (full, ½, » for 15 min) of bupivacaine, ropivacaine, morphine, M6G or saline control. Adenosine triphosphate content of 798 beads was measured 3 days post-incubation to assess cell viability. RESULTS: A clear ranking of cytotoxic potency: bupivacaine > ropivacaine > morphine = M6G = saline was observed. Results reveal a dose- and time-dependent manner of cytotoxic effects on human chondrocytes for bupivacaine and ropivacaine but not for opioids. Cell viability after exposure to morphine and M6G was comparable to exposure to saline. CONCLUSION: The results confirm dose- and time-dependent cytotoxic effects on human chondrocytes for amide-type local anaesthetics. This study confirms the safety of morphine and M6G in terms of an absence of cytotoxic effects after intra-articular application, making them safe potential alternatives in clinical practice.

Can thrombin-activated platelet releasate compensate the age-induced decrease in cell proliferation of MSC?

Mesenchymal progenitor cells (MSCs) are promising for cell-based regeneration therapies. In elderly patients a reduced proliferation of MSCs has been described. Platelet-rich plasma (PRP) contains important factors necessary for osteogenic regeneration. The aim of this study was to find out whether the age-induced decrease in cell proliferation can be compensated by the use of supernatant of centrifuged, activated PRP (tPR). MSCs of donors of three age groups (A: young, 14-16 years, B: middle age, 36-46 years, C: older, 74-83 years) were expanded with 20% FCS alone or supplemented with thrombin-activated platelet releasate (tPR) (1%, 2.5%, and 5%) or platelet-poor plasma (PPP 5%). Cell proliferation and differentiation was measured on days 0, 3, and 7. Proliferation increased significantly in groups A and B with tPR, and non-significantly in group C. The generation times of MSCs of elderly patients were significantly increased in group C compared to groups A and B. Addition of 1% or 2.5% tPR significantly reduced population doubling times of all age groups. Adding tPR stimulates the proliferation rate of MSCs independent of donor age. For juvenile and middle-aged patients this influence was significant. Cells differentiation into osteoblasts was not influenced by addition of tPR.