Mesenchymal Stem Cell-derived Extracellular Vesicles Prevent Experimental Bronchopulmonary Dysplasia Complicated By Pulmonary Hypertension.

Mesenchymal stem cell (MSC) extracellular vesicles (EVs) have beneficial effects in preclinical bronchopulmonary dysplasia and pulmonary hypertension (BPD-PH) models. The optimal source, dosing, route, and duration of effects are however unknown. The objectives of this study were to (a) compare the efficacy of GMP-grade EVs obtained from Wharton's Jelly MSCs (WJ-MSCs) and bone marrow (BM-MSCs), (b) determine the optimal dosing and route of administration, (c) evaluate its long-term effects, and (d) determine how MSC EVs alter the lung transcriptome. Newborn rats exposed to normoxia or hyperoxia (85% O2) from postnatal day (P)1-P14 were given (a) intra-tracheal (IT) BM or WJ-MSC EVs or placebo, (b) varying doses of IT WJ-MSC EVs, or (c) IT or intravenous (IV) WJ-MSC EVs on P3. Rats were evaluated at P14 or 3 months. Early administration of IT BM-MSC or WJ-MSC EVs had similar beneficial effects on lung structure and PH in hyperoxia-exposed rats. WJ-MSC EVs however had superior effects on cardiac remodeling. Low, medium, and high dose WJ-MSC EVs had similar cardiopulmonary regenerative effects. IT and IV WJ-MSC EVs similarly improved vascular density and reduced PH in hyperoxic rats. Gene-set enrichment analysis of transcripts differentially expressed in WJ-MSC EV-treated rats showed that induced transcripts were associated with angiogenesis. Long-term studies demonstrated that a single early MSC EV dose has pulmonary vascular protective effects 3 months after administration. Together, our findings have significant translational implications as it provides critical insight into the optimal source, dosing, route, mechanisms of action, and duration of effects of MSC-EVs for BPD-PH.

Successful haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide in a child with X-linked chronic granulomatous disease: A first report in Asia.

BACKGROUND: HLA-matched hematopoietic stem cell transplantation (HSCT) is the curative treatment for chronic granulomatous disease (CGD). OBJECTIVE: To report a case of X-linked CGD with active infection successfully treated by haploidentical HSCT with post-transplant high dose cyclophosphamide (PTCY). METHODS: A 5-year-old Thai boy with CGD was undergone for haploidentical HSCT using PTCY with correction of the phagocytic function. He presented with Chromobacterium violaceum liver abscess at the age of 9 months and experienced recurrent perianal abscess and invasive pulmonary aspergillosis even receiving antimicrobial prophylaxis. PTCY was given on day 3 and 4, after CD34+ cells infusion. RESULTS: The peripheral blood-nucleated cell chimerism showed 100% on day 16 and remained 100%. Dihydrorhodamine (DHR) assay on day 108 and day 214 showed normal results. Currently at 22 months post HSCT, he does not receive antibiotic and anti-fungal prophylaxis. CONCLUSIONS: Haploidentical HSCT with PTCY could be an effective treatment option for children with CGD.