No indication of aberrant neutrophil extracellular trap release in indolent or advanced systemic mastocytosis

In disease states with chronic inflammation, there is a crosstalk between mast cells and neutrophil granulocytes in the inflamed microenvironment, which may be potentiated by tryptase. In systemic mastocytosis (SM), mast cells are constitutively active and tryptase is elevated in blood. Mast cell activation in SM leads to symptoms from various organs depending on where the active mast cells reside, for example, palpitations, flush, allergic symptoms including anaphylactic reactions, and osteoporosis. Whether neutrophil function is altered in SM is not well understood. In the current study, we assessed nucleosomal citrullinated histone H3 (H3Cit-DNA) as a proxy for neutrophil extracellular trap release in plasma from 55 patients with indolent and advanced SM. We observed a strong trend towards a correlation between leukocyte count, eosinophil count and neutrophil count and H3Cit-DNA levels in patients with advanced SM but not in indolent SM; however, no differences in H3Cit-DNA levels in SM patients compared with healthy controls. H3Cit-DNA levels did not correlate with SM disease burden, tryptase levels, history of anaphylaxis or presence of cutaneous mastocytosis; thus, there is no evidence of a general neutrophil extracellular trap release in SM. Interestingly, H3Cit-DNA levels and leukocyte counts were elevated in a subgroup of SM patients with aberrant mast cell CD2 expression, which warrants further investigation. In conclusion, we found no evidence of global increase in neutrophil extracellular trap release in SM.

Proteomic and transcriptomic screening demonstrates increased mast cell-derived CCL23 in systemic mastocytosis

BACKGROUND

Systemic mastocytosis (SM) is a heterogeneous group of mast cell-driven diseases diagnosed by bone marrow sampling. However, there are a limited number of available blood disease biomarkers.

OBJECTIVE

Our aim was to identify mast cell-derived proteins that could potentially serve as blood biomarkers for indolent and advanced forms of SM.

METHODS

We performed a plasma proteomics screening coupled with single-cell transcriptomic analysis in SM patients and healthy subjects.

RESULTS

Plasma proteomics screening identified 19 proteins upregulated in indolent disease compared to healthy, and 16 proteins in advanced disease compared to indolent. Among these, 5 proteins, CCL19, CCL23, CXCL13, IL-10, and IL-12Rβ1, were higher in indolent relative to healthy and in advanced disease compared to indolent. Single-cell RNA sequencing demonstrated that CCL23, IL-10, and IL-6 were selectively produced by mast cells. Notably, plasma CCL23 levels correlated positively with known markers of SM disease severity, namely tryptase levels, percentage bone marrow mast cell infiltration, and IL-6.

CONCLUSION

CCL23 is produced predominantly by mast cells in SM, and CCL23 plasma levels are associated with disease severity, correlating positively with established markers of disease burden, thus suggesting that CCL23 is a specific SM biomarker. In addition, the combination of CCL19, CCL23, CXCL13, IL-10, and IL-12Rβ1 may be useful for defining disease stage.

Influence of continuous phase viscosity on emulsification by ultrasound

Power ultrasound is one means among others of mechanically producing emulsions. In spite of numerous publications on the basic principles of this technique, there is insufficient knowledge of continuous ultrasound emulsification processes and the main parameters of practical relevance. A comparison of this system with other continuous mechanical emulsifying devices is made. The effect of continuous phase viscosity on droplet disruption due to ultrasound is the subject of a more detailed investigation. Continuous phase viscosity is varied by means of water soluble stabilizers (o/w systems) and different oils (w/o systems). At constant energy density, droplet size decreases when adding stabilizers, whereas the viscosity of the oil in w/o emulsions has no effect. Qualitative investigations of the local distribution of cavitation have shown very small penetration depths of cavitation into the liquid. This emphasizes the need for improvement of apparatus design to optimize the emulsification process.