Characterization of Extracellular Vesicles in Osteoporotic Patients Compared to Osteopenic and Healthy Controls.

Extracellular vesicles (EVs) are mediators of a range of pathological conditions. However, their role in bone loss disease has not been well understood. In this study we characterized plasma EVs of 54 osteoporotic (OP) postmenopausal women compared to 48 osteopenic (OPN) and 44 healthy controls (CN), and we investigated their effects on osteoclasts and osteoblasts. We found no differences between the three groups in terms of anthropometric measurements and biochemical evaluation of serum calcium, phosphate, creatinine, PTH, 25-hydroxy vitamin D and bone biomarkers, except for an increase of CTX level in OP group. FACS analysis revealed that OP patients presented a significantly increased number of EVs and RANKL+ EVs compared with both CN and OPN subjects. Total EVs are negatively associated with the lumbar spine T-score and femoral neck T-score. Only in the OPN patients we observed a positive association between the total number of EVs and RANKL+ EVs with the serum RANKL. In vitro studies revealed that OP EVs supported osteoclastogenesis of healthy donor peripheral blood mononuclear cells at the same level observed following RANKL and M-CSF treatment, reduced the ability of mesenchymal stem cells to differentiate into osteoblasts, while inducing an increase of OSTERIX and RANKL expression in mature osteoblasts. The analysis of miRNome revealed that miR-1246 and miR-1224-5p were the most upregulated and downregulated in OP EVs; the modulated EV-miRNAs in OP and OPN compared to CN are related to osteoclast differentiation, interleukin-13 production and regulation of canonical WNT pathway. A proteomic comparison between OPN and CN EVs evidenced a decrease in fibrinogen, vitronectin, and clusterin and an increase in coagulation factors and apolipoprotein, which was also upregulated in OP EVs. Interestingly, an increase in RANKL+ EVs and exosomal miR-1246 was also observed in samples from patients affected by Gorham-Stout disease, suggesting that EVs could be good candidate as bone loss disease biomarkers. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Expanding the novel MAPKAPK5-related developmental disorder's genotype-phenotype correlation: Patient report and 19 months of follow-up.

This study aimed to widen the knowledge of a recently identified, autosomal-recessive, multiple congenital anomalies syndrome to date observed in only other three children. This is the second report of biallelic mutations in MAPKAPK5 whose impairment during human development has been associated with neurological, cardiac, and facial anomalies combined with fingers and toes malformations. Through the affected patients' genetic and phenotypic features overlap, this report confirms MAPKAPK5 as causative gene and adds unique neurodevelopmental characterization. Moreover, based on the complex congenital genitourinary anomalies reported and MAPKAPK5 literature review, we also propose kidney and external genitalia involvement as a key syndromic feature whose expressivity may be more severe in males.

Stimulation of Treg Cells to Inhibit Osteoclastogenesis in Gorham-Stout Disease.

Gorham-Stout disease (GSD) is a very rare syndrome displaying excessive bone erosion and vascular lesion. Due to the rarity of the disease and to the limited studies, its etiopathogenesis is not entirely known. The involvement of immune system in the progressive osteolysis was recently suggested. Indeed, extensive reciprocal interactions between the immune and skeletal systems have been demonstrated. This study aimed to evaluate alterations of immune cells in GSD. An increase of CD8+ cells and reduction of CD4+ and CD4+CD25+CD127low cells was revealed in patients. Interestingly, patients' regulatory T cells maintain the ability to respond to extracellular stimuli and to regulate osteoclastogenesis; GSD cells proliferate under aCD3/CD28 signal reaching similar levels to those observed in control culture and exert their immunomodulatory activity on effector T cells. GSD Treg cells preserved their inhibitory effects on the osteoclastogenesis. These results suggest that stimulation of Treg cells could open the way for the identification and testing of new therapeutic approaches for patients affected by GSD.

Dysregulated miRNAs in bone cells of patients with Gorham-Stout disease.

Gorham-Stout disease (GSD) is a very rare disease characterized by increased bone erosion with angiomatous proliferation. The mechanisms underlying this disorder have not been deeply investigated. Due to its rarity, no guidelines are currently available for treatment and management of GSD. We recently evaluated the cellular alterations of the bone remodeling in patients showing that osteoclast precursors displayed increased ability to differentiate into osteoclasts and that affected osteoclasts resorb bone more actively than control cells. Moreover, osteoblasts isolated from a patient showed a defective ability to form mineralized nodules. In this paper, we investigated the molecular pathways involved in the cellular defects of GSD bone cells. For this study, we recruited nine patients and performed miRNome analysis of bone cells. Between the 178 miRNAs robustly expressed in GSD osteoclasts, significant modulation of three miRNAs (miR-1246, miR-1-3p, and miR-137-3p) involved in the regulation of osteoclast formation and activity or in the angiomatous proliferation was found in patients' cells. Interestingly, miR-1246 was also up-regulated in serum exosomes from patients. Analysis of miRNAs from patient osteoblasts suggested alteration of miR-204a-5p, miR-615-3p and miR-378a-3p regulating osteoblast function and differentiation. The resulting miRNA pattern may help to understand better the mechanisms involved in GSD and to identify new potential therapeutic targets for this rare disease.

Diffuse infantile hepatic hemangiomas in a patient with Beckwith-Wiedemann syndrome: A new association?

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome, caused by alterations in a cluster of imprinted genes located within the chromosome region 11p15.5. Common clinical features are overgrowth, macroglossia, lateralized overgrowth, abdominal wall defects, neonatal hypoglycemia and an increased risk of embryonal tumors, such as hepatoblastomas. Periodic screening for abdominal tumors is recommended. Vascular tumors are uncommon in BWS. Diffuse infantile hepatic hemangiomas (DIHHs) are rare vascular tumors with potentially lethal complications, in particular acquired consumptive hypothyroidism, high-output cardiac failure, liver failure and abdominal compartment syndrome. We describe a 2-month-old patient with hallmark clinical features of BWS and confirmed a genetic diagnosis with mosaic paternal uniparental disomy of chromosome 11p15.5 (UPD[11]pat). The patient developed hepatomegaly and elevated alpha-fetoprotein (AFP) and was therefore suspected of having a hepatoblastoma. Abdominal echo-color Doppler and a CT-scan allowed diagnosis of DIHHs. She was closely monitored and underwent treatment with propranolol. Oral propranolol was effective in reducing hepatic lesions without side effects. This report may suggest that vascular tumors can also be associated with BWS.

Dissecting the mechanisms of bone loss in Gorham-Stout disease.

Gorham-Stout disease (GSD) is a rare disorder characterized by progressive osteolysis and angiomatous proliferation. Since the mechanisms leading to bone loss in GSD are not completely understood, we performed histological, serum, cellular and molecular analyses of 7 patients. Increased vessels, osteoclast number and osteocyte lacunar area were revealed in patients' bone biopsies. Biochemical analysis of sera showed high levels of ICTP, Sclerostin, VEGF-A and IL-6. In vitro experiments revealed increased osteoclast differentiation and activity, and impaired mineralization ability of osteoblasts. To evaluate the involvement of systemic factors in GSD, control cells were treated with patients' sera and displayed an increase of osteoclastogenesis, bone resorption activity and a reduction of osteoblast function. Interestingly, GSD sera stimulated the vessel formation by endothelial cells EA.hy926. These results suggest that bone cell autonomous alterations with the cooperation of systemic factors are involved in massive bone loss and angiomatous proliferation observed in GSD patients.

Treatment of homozygous familial hypercholesterolaemia in paediatric patients: A monocentric experience.

Background Homozygous familial hypercholesterolaemia is a rare life-threatening disease characterized by markedly elevated low-density lipoprotein cholesterol (LDL-C) concentrations and accelerated atherosclerosis. The presence of double gene defects in the LDL-Receptor, either the same defect (homozygous) or two different LDL-raising mutations (compound heterozygotes) or other variants, identify the homozygous phenotype (HopFH). Apheresis is a procedure in which plasma is separated from red blood cells before the physical removal of LDL-C or the LDL-C is directly removed from whole blood. It is currently the treatment of choice for patients with HopFH whose LDL-C levels are not able to be reduced to target levels with conventional lipid-lowering drug therapy. Design The aim of this study is to report a cohort of six paediatric patients and to evaluate the long term efficacy of combined medical therapy and LDL-apheresis on LDL-C reduction. Methods We collected data from six children with confirmed diagnosis of HopFH (two females and four males; age range at diagnosis 3-8 years, mean 6 ± 1 years) from a single clinical hospital in Italy from 2007 to 2017. Results Clinical manifestations and outcomes may greatly vary in children with HopFH. Medical therapy and LDL-apheresis for the severe form should be started promptly in order to prevent cardiovascular disease. Conclusions Lipoprotein apheresis is a very important tool in managing patients with HopFH at high risk of cardiovascular disease. Based on our experience and the literature data, the method is feasible in very young children, efficient regarding biological results and cardiac events, and safe with minor side-effects and technical problems. We advise treating homozygous and compound heterozygous children as soon as possible.

NK cell effector functions in a Chédiak-Higashi patient undergoing cord blood transplantation: Effects of in vitro treatment with IL-2.

NK cell cytotoxicity in Chédiak-Higashi syndrome (CHS) is strongly impaired as lytic granules are not released upon NK-target cell contact, contributing to several defects typical of this severe immunodeficiency. Correction of NK cell defects in CHS should improve the outcome of hematopoietic stem-cell transplantation, proposed as therapy. We investigated NK cell functions in a CHS patient before and after cord-blood transplantation, and the ability of in vitro IL-2 treatment to restore them. Before the transplant, the strong defect in NK cell-mediated natural and antibody-dependent cytotoxicity, as well as in IFN-γ production, could be restored up to normal levels by in vitro IL-2 treatment. This cytokine also caused the appearance of smaller lysosomal granules and their orientation towards the NK-target cell contact area, thus suggesting that IL-2 had a more general capacity to restore NK cell effector functions. Moreover after the transplant, although the successful engraftment, NK cell cytotoxicity resulted still partially impaired at one year, almost normal at ten years and, anyhow, fully recovered by in vitro IL-2 treatment. Taken together, our results indicate that IL-2 had a wide capacity to restore NK cell effector functions, being able to reverse the altered cytotoxic activity, lytic granule pattern, and cytokine production observed in the CHS patient.

Assent, consent and paediatric bioethics. Commentary.

In the ethics of relations between physicians and paediatric patients the question of autonomy and its corollary, consent, is crucial. While the importance attached to autonomy in the clinical setting is not the same as that accorded in research, it nonetheless assumes greater relevance when minors are involved, and a careful case-by-case assessment becomes obligatory.

For an alliance between science, ethics and politics in promoting paediatric trials. Commentary.

After several decades during which children tended to be excluded from clinical trials, provisions to encourage trials with children have been in place for some years both at international level and in individual countries. The Nuffield Council on Bioethics has published a broad-ranging report on the subject, which makes concrete proposals for decision-makers and comes at a crucial moment in the definition of European Union regulations on this topic.

Longitudinal Evaluation of Immune Reconstitution and B-cell Function After Hematopoietic Cell Transplantation for Primary Immunodeficiency.

PURPOSE: Hematopoietic cell transplantation (HCT) provides a curative therapy for severe forms of primary immunodeficiencies (PID). While the timing and extent of T-cell reconstitution following transplant for PID has been studied in depth, less is known about the kinetics of B-cell development and long-term restoration of humoral functions, which been often reported to be suboptimal after HCT. METHODS: We studied longitudinally B-cell development and function in a cohort of 13 PID patients transplanted between 1997 and 2010, with a follow-up ranging from 0.7 to 15 years. Flow cytometric analysis of naïve and antigen-experienced B-cell subsets and in vitro functional responses to CpG were compared with data from healthy children and correlated with the degree of B-cell chimerism and in vivo antibody production. RESULTS: We found that total memory B-cells count remained below normal levels for the first 2 years of follow up and progressively normalized. Switched memory B-cells (CD19+CD27+IgD-IgM-) were restored early and better than IgM memory B-cells (CD19+CD27+IgD+IgM+), which remained significantly reduced long-term. The recovery of memory B-cells correlated with good in vivo humoral function and normalization of CpG-response. A complete B-cell reconstitution was usually associated with donor B-cells chimerism and pre-transplant conditioning. Donor source and the underlying genetic defect represented also important variables. CONCLUSION: Monitoring of phenotypic and functional changes on B-cells following HCT may prove clinically relevant to tailor patients' care. In particular the analysis of IgM memory and switched memory B-cells in addition to in vitro B-cells stimulation are recommended before Ig replacement therapy (IgRT) discontinuation.