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- Hagey, DW, et al.
(författare)
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Myeloid cells from Langerhans cell histiocytosis patients exhibit increased vesicle trafficking and an altered secretome capable of activating NK cells
- 2023
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 108:9, s. 2422-2434
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Tidskriftsartikel (refereegranskat)abstract
- Langerhans cell histiocytosis (LCH) is a potentially life-threatening inflammatory myeloid neoplasia linked to paediatric neurodegeneration, whereby transformed LCH cells form agglomerated lesions in various organs. Although MAP-kinase pathway mutations have been identified in LCH cells, the functional consequences of these mutations and the mechanisms that cause the pathogenic behaviour of LCH cells are not well understood. In our study, we used an in vitro differentiation system and RNA-sequencing to compare monocyte-derived dendritic cells from LCH patients to those derived from healthy controls or patients with Crohn’s disease, a non-histiocytic inflammatory disease. We observed that Interferon-γ treatment exacerbated intrinsic differences between LCH patient and control cells, including strikingly increased endoand exocytosis gene activity in LCH patients. We validated these transcriptional patterns in lesions and functionally confirmed that LCH cells exhibited increased endo- and exocytosis. Furthermore, RNA-sequencing of extracellular vesicles (EV) revealed the enrichment of pathological transcripts involved in cell adhesion, MAP-kinase pathway, vesicle trafficking and T-cell activation in LCH patients. Thus, we tested the effect of the LCH secretome on lymphocyte activity and found significant activation of NK cells. These findings implicate EVs in the pathology of LCH for the first time, in line with their established roles in the formation of various other tumour niches. Thus, we describe novel traits of LCH patient cells and suggest a pathogenic mechanism of potential therapeutic and diagnostic importance.
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- Greenwood, Tatiana von Bahr, et al.
(författare)
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Clinical and laboratory signs of haemophagocytic lymphohistiocytosis associated with pandemic influenza A (H1N1) infection in patients needing extracorporeal membrane oxygenation A retrospective observational study
- 2021
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Ingår i: European Journal of Anaesthesiology. - : Lippincott Williams & Wilkins. - 0265-0215 .- 1365-2346. ; 38:7, s. 692-701
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Severe pandemic influenza has been associated with the hyperinflammatory condition secondary haemophagocytic lymphohistiocytosis (HLH).OBJECTIVES: To determine the frequency, degree, character and possible cause of influenza-associated HLH in critically ill patients with severe acute respiratory distress syndrome due to influenza A (H1N1) infection requiring extracorporeal membrane oxygenation (ECMO) support at our hospital.DESIGN: A retrospective observational study.PATIENTS AND SETTING: Medical data were retrieved retrospectively from 11 consenting patients of thirteen adults infected with pandemic influenza A (H1N1) 2009 requiring ECMO between July 2009 and January 2010 at the ECMO Centre of Karolinska University Hospital, Stockholm, Sweden. All patients were evaluated for HLH using HLH-2004 criteria and HScore.RESULTS: Eleven patients (median age 31 years) were included in the study and all survived. All patients showed signs of multiple organ dysfunction and pronounced inflammation, more severe in the four patients with HLH who had significantly higher peak serum concentrations of ferritin (P = 0.024), alkaline phosphatase (P = 0.012) and gamma-glutamyl transferase (P = 0.024), lower concentration of albumin (P = 0.0086) and more frequently hepatomegaly (P = 0.048). Abnormal lymphocyte cytotoxicity (lytic units <10) and a low proportion of natural killer (NK) cells were observed in three of four patients with HLH. Notably, we found a significant inverse correlation between serum ferritin concentration and NK cell and cytotoxic T lymphocyte percentages (r(s) = -0.74, P = 0.0013 and r(s) = -0.79, P = 0.0025, respectively). One HLH patient received HLH-directed cytotoxic therapy, another intravenous immunoglobulin and the other two no specific HLH-directed therapy.CONCLUSION: Critically ill patients, including healthy young adults, with pandemic influenza may develop HLH and should be monitored for signs of hyperinflammation and increasing organ dysfunction, and evaluated promptly for HLH because HLH-directed therapy may then be beneficial. The association of low NK percentages with hyperferritinaemia may suggest a role for reduced NK cell numbers, possibly also cytotoxic T lymphocytes, and subsequently reduced lymphocyte cytotoxicity, in the pathogenesis of hyperinflammation and secondary HLH.
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- von Bahr Greenwood, Tatiana, et al.
(författare)
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Elevated ferritin and soluble CD25 in critically ill are associated with parameters of (hyper)inflammation and lymphocyte cytotoxicity
- 2019
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Ingår i: Minerva Anestesiologica. - : Edizioni Minerva Medica. - 0375-9393 .- 1827-1596. ; 85:12, s. 1289-1298
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Critically ill may develop a potentially fatal hyperinflammation, secondary (acquired) hemophagocytic lymphohistiocytosis (sHLH), the cause of which is unclear. We evaluated serum ferritin and soluble CD25 (sCD25) in critically ill, and their association with other parameters of inflammation and critical illness. Moreover, aiming to better understand the pathogenesis of sHLH, we also evaluated lymphocyte cytotoxicity parameters and correlations with the inflammatory markers ferritin and sCD25.METHODS: In a prospective observational study, 32 patients with ferritin ≥500 μg/L (24 with sepsis) were studied on admission to an intensive care unit (ICU) with regard to ferritin and corresponding clinical and laboratory features including sCD25, and detailed lymphocyte cytotoxicity and genetic analyses whenever possible.RESULTS: Critically ill patients had elevated, positively correlated levels of serum ferritin and sCD25 (rs=0.465, p=0.008); both associated with other risk factors of poorer outcome in critically ill, such as thrombocytopenia (rs=-0.534, p=0.002 and rs=-0.421, p=0.018, respectively), and sCD25 with hypoalbuminemia (rs=-0.678, p<0.001) and life support treatments (rs=0.479, p=0.006). Interestingly, ferritin levels were inversely associated with NK- cell cytotoxicity (rs=-0.462, p=0.047) and degranulation (rs=-0.504, p=0.030). Moreover, of four patients with abnormally low cytotoxicity, three (75%) had <5% circulating NK-cells.CONCLUSIONS: Our study suggests that hyperferritinemia and sCD25 correlate with other laboratory parameters indicative of severe hyperinflammation and organ dysfunction in critically ill ICU-patients, indicating their value in identifying hyperinflammatory critically ill patients for early intervention. Furthermore, it suggests that hyperferritinemia and hyperinflammation may partly be associated with a low percentage circulating NK-cells, and hence, the associated low lymphocyte cytotoxicity.
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