Reduction of CFU-GM and circulating hematopoietic progenitors in a subgroup of children with chronic neutropenia associated with severe infections and delayed recovery

Royal Jelly Increases Hematopoietic Stem Cells in Peripheral Blood: A Double-Blind, Placebo-Controlled, Randomized Trial in Healthy Subjects

Objectives

Royal jelly (RJ), produced by honeybees, influences stem cell functions, such as pluripotency maintenance of mouse embryonic stem cells and prevention of aging-related muscle stem cell functional deterioration. Thus, we hypothesized that RJ administration has various health-promoting effects based on stem cells. However, its effects are unknown in humans. In this study, we have attempted for the first time to clarify whether the administration of RJ in humans affects stem cells.

Materials and Methods

This randomized, double-blind, placebo-controlled study was performed on healthy subjects (n = 90) who received protease-treated RJ at a dose of 1200 mg/day or placebo daily for four weeks. Also, the participants with a low number of hematopoietic stem cells (HSCs) in peripheral blood were preferentially selected. HSC counts, endothelial progenitor cell (EPC) counts, blood cell counts in peripheral blood, cytokines in serum, and physical conditions were evaluated. Results and Conclusion. Eligible data from 86 subjects (placebo: 42, RJ: 44) who completed the study were analyzed. There were no significant differences between the two groups regarding the changes in peripheral HSC count (p=0.103), while diastolic blood pressure showed a significant improvement in the RJ group compared to that in the placebo group (p=0.032). The subgroup analysis excluded 14 subjects who complained of cold symptoms at baseline or within five days of the four-week study. The changes in the HSC populations were significantly higher in the RJ group than those in the placebo group (p=0.042). No adverse effects were observed in any of the groups. These results suggest that RJ administration affected the peripheral HSC count and may influence stem cell functions. Further research is needed to reveal the various health-promoting benefits of RJ based on stem cells.

Polystyrene micro-/nanoplastics induced hematopoietic damages via the crosstalk of gut microbiota, metabolites, and cytokines

Micro-/nanoplastics (MNPLs), novel environmental pollutants, widely exist in the environment and life and bring health risks. Previous studies have shown that NMPLs can penetrate bone marrow, but whether they cause hematopoietic damage remains uncertain. In this study, C57BL/6J mice were treated with polystyrene MNPLs (PS-MNPLs, 10 μm, 5 μm and 80 nm) at 60 μg doses for 42 days by intragastric administration. We evaluated the hematopoietic toxicity induced by MNPLs and potential mechanisms via combining 16S rRNA, metabolomics, and cytokine chips. The results demonstrated that PS-MNPLs induced hematopoietic toxicity, which was manifested by the disorder of bone marrow cell arrangement, the reduction in colony-forming, self-renewal and differentiation capacity, and the increased proportion of lymphocytes. PS-MNPLs also disrupted the homeostasis of the gut microbiota, metabolism, and inflammation, all of which were correlated with hematotoxicity, suggesting that abnormal gut microbiota-metabolite-cytokine axes might be the crucial pathways in MNPLs-induced hematopoietic injury. In conclusion, our study systematically demonstrated that multi-scale PS-MNPLs induced hematopoietic toxicity via the crosstalk of gut microbiota, metabolites, and cytokines and provided valuable insights into MNPLs toxicity, which was conducive to health risk assessment and informed policy decisions regarding PS-MNPLs.

The blood protein hCAP-18 in neutropenia: An 18-month experience of a new ELISA for clinical use

Neutropenia as an isolated clinical finding may include aetiologies ranging from severe disease to a transient condition, and differential diagnosis may be challenging. Previous data and clinical experience suggest that low levels of the neutrophil-derived protein human 18 kDa cathelicidin antimicrobial protein (hCAP-18) in the blood are predictive of more severe forms of neutropenia. The objective of this study was to present the results from a newly developed ELISA method that has been used in clinical routine in Sweden since 2018 for quantification of hCAP-18 in blood plasma. Using this method, we report that patients with severe disease analysed during the study period presented with low or undetectable levels of blood plasma hCAP-18, validating its use as screening tool for severe neutropenia. Furthermore, neutropenic patients as a group displayed lower levels of hCAP-18 as compared to blood donors. Within the group of neutropenic patients, those with neutrophil antibodies displayed significantly higher hCAP-18 levels compared to patients with idiopathic neutropenia. By including an analysis of hCAP-18 in the primary investigation of neutropenia, an increased accuracy in differential diagnosis is achieved, thus contributing to reduced costs of neutropenia management.