The NLRP3 gene mutations are the cause of autosomal dominant autoinflammatory disorders (NLRP3-AID). Recently, hearing loss (HL) has been found to be the sole or major manifestation of NLRP3-AID. Here, we tested 110 autosomal dominant HL families with a custom panel of 237 HL genes and found one family carrying the NLRP3 c.1872C>G, p.Ser624Arg mutation. Functional studies revealed that this novel variant is a gain of function mutation, leading to increased activity of caspase-1 and subsequent oversecretion of proinflammatory interleukin-1β. Clinical reanalysis of the affected individuals, together with serological evidence of inflammation and pathological cochlear enhancement on FLAIR-MRI images, guided our diagnosis to atypical NLRP3-AID. The study highlights the role of genetic analysis in patients with progressive postlingual HL. This can help to identify individuals with hereditary HL as a consequence of NLRP3-AID and allow timely and effective treatment with interleukin-1-receptor antagonist.

Purpose:The development of targeted biological therapies for coronavirus disease 2019 (COVID-19) requires reliable biomarkers that could help indicate how patients are responding. The hyperactivation of inflammasomes by the SARS-CoV2 virus is hypothesized to contribute to a more severe course of the COVID-19 disease. Therefore, we aimed to evaluate the prognostic value of several inflammasome-related cytokines and proteins upon admission to the intensive care unit (ICU).Patients and Methods:We performed a prospective cohort study. Plasma samples were obtained from 45 critically ill COVID-19 patients and 10 patients without any signs of infection (traumatic brain injury [TBI]) on admission to the ICU. Concentrations of IL-1a, IL-1β, IL-18, IL-1RA, galectin-1, apoptosis-associated speck-like proteins, LDH, ferritin, and gasdermin D were analyzed. A cell-free caspase-1 plasma assay was done by inhibitor-based immunoprecipitation followed by a Western Blot. Demographic and clinical characteristics were recorded.Results:Inhospital mortality in COVID-19 patients was 62%. Galectin-1 was 1.8-fold lower in COVID-19 than in TBI patients (17101.84 pg/mL vs. 30764.20 pg/mL, P = 0.007), but other inflammasome-related biomarkers had similar concentrations. Patients with a Sequential Organ Failure Assessment (SOFA) score of > 9 on admission who were at high risk of death had significantly higher galectin-1 but lower IL-1RA in comparison with low-risk patients (25551.3 pg/mL vs. 16302.7 pg/mL, P = 0.014; 14.5 pg/mL vs. 39.4pg/mL, P = 0.04, respectively). Statistically significant correlations were observed between: IL-1a and platelets (r = –0.37), IL-1 β and platelets (r = –0.36), ferritin and INR (r = 0.39). Activated caspase-1 p35, whose presence was related to higher fibrinogen and lower D-dimers, was detected in 12 out of 22 COVID-19 patients and in none of the TBI patients. Moreover, densitometric analysis showed a significantly higher amount of p35 in patients with a SOFA score > 9.Conclusion:We found that the systemic markers of activation of inflammasomes in critically ill COVID-19 patients were not directly related to outcome. Therefore, potential interventions aimed at the inflammasome pathway in this group of patients may be of limited effectiveness and should be biomarker-guided.

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Adult hematopoietic stem and progenitor cells (HSPCs) respond to bacterial infections by expansion to myeloid cells. Sepsis impairs this process by suppressing differentiation of stem cells subsequently contributing to an ineffective immune response. Whether the magnitude of HSPCs impairment in sepsis is severity-dependent remains unknown. This study investigated dynamics of the HSPC immune-inflammatory response in the bone marrow, splenic, and blood compartments in moribund and surviving septic mice. The 12-week-old outbred CD-1 female mice (n=65) were subjected to a cecal ligation and puncture (CLP) sepsis, treated with antibiotics and fluid resuscitation, and stratified into predicted-to-die (P-DIE) and predicted-to-survive (P-SUR) cohorts for analysis. CLP strongly reduced the common myeloid and multipotent progenitors, short- and long-term hematopoietic stem cell (HSC) counts in the bone marrow; lineage−ckit+Sca-1+ and short-term HSC suppression was greater in P-DIE versus P-SUR mice. A profound depletion of the common myeloid progenitors occurred in the blood (by 75%) and spleen (by 77%) of P-DIE. In P-SUR, most common circulating HSPCs subpopulations recovered to baseline by 72 h post-CLP. Analysis of activated caspase-1/-3/-7 revealed an increased apoptotic (by 30%) but not pyroptotic signaling in the bone marrow HSCs of P-DIE mice. The bone marrow from P-DIE mice revealed spikes of IL-6 (by 5-fold), CXCL1/KC (15-fold), CCL3/MIP-1α (1.7-fold), and CCL2/MCP-1 (2.8-fold) versus P-SUR and control (TNF, IFN-γ, IL-1β, -5, -10 remained unaltered). Summarizing, our findings demonstrate that an early sepsis-induced impairment of myelopoiesis is strongly outcome-dependent but varies among compartments. It is suggestive that the HSCPC loss is at least partly due to an increased apoptosis but not pyroptosis.

PurposeDevelopment of targeted biological therapies for COVID-19 requires reliable biomarkers that could help indicate the responding patients. Hyperactivation of the inflammasome by SARS-CoV2 virus is hypothesized to contribute to severe course of the COVID-19 disease. Therefore, we aimed to evaluate the prognostic value of several inflammasome-related cytokines and proteins at the admission to the intensive care unit (ICU).Patients and methodsPlasma samples were obtained from 45 critically ill COVID-19 patients and from10 patients with severe traumatic brain injury (TBI) at the admission to the ICU. The concentration of IL-1α, IL-1β, IL-18, IL-1RA, galectin-1, ASC, LDH, ferritin, and gasdermin D were analyzed. A novel cell-free caspase-1 plasma assay was developed by inhibitor-based immunoprecipitation followed by Western Blot. Demographic and clinical characteristics were recorded.ResultsThe inflammasome-related biomarkers were in similar concentration in COVID-19 and TBI patients except for galectin-1 being lower in the former. None of the tested markers were related to the outcome, length of stay or development of secondary infections. Patients with SOFA score of >9 at admission who were at high risk of death had significantly higher galectin-1 but lower IL-1RA in comparison to low-risk patients. Weak but significant correlations were observed between: IL-1α and platelets, IL-1β and platelets, ferritin and INR. Activated caspase-1 p35 was detectable in 12/22 COVID-19 patients but in none of the TBI patients. Its presence was related with higher fibrinogen and lower D-dimers. It was also significantly higher in patients with SOFA>9.ConclusionOur results indicate that the activation of the inflammasome in critically ill COVID-19 patients is a heterogenous process and is not directly related with outcome. Therefore, potential interventions aimed at the inflammasome pathway in this group of patients may be of limited effectiveness and should be biomarker-guided.