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Objectives@#. Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by recurrent epistaxis, telangiectasia, and visceral arteriovenous malformations (AVMs). Activin A receptor-like type 1 (ACVRL1/ALK1) and endoglin (ENG) are the principal genes whose mutations cause HHT. No multicenter study has yet investigated correlations between genetic variations and clinical outcomes in Korean HHT patients. @*Methods@#. Seventy-two members from 40 families suspected to have HHT based on symptoms were genetically screened for pathogenic variants of ACVRL1 and ENG. Patients with genetically diagnosed HHT were also evaluated. @*Results@#. In the HHT genetic screening, 42 patients from 24 of the 40 families had genetic variants that met the pathogenic criteria (pathogenic very strong, pathogenic strong, pathogenic moderate, or pathogenic supporting) based on the American College of Medical Genetics and Genomics Standards and Guidelines for either ENG or ACVRL1: 26 from 12 families (50%) for ENG, and 16 from 12 families (50%) for ACVRL1. Diagnostic screening of 42 genetically positive HHT patients based on the Curaçao criteria revealed that 24 patients (57%) were classified as having definite HHT, 17 (41%) as having probable HHT, and 1 (2%) as unlikely to have HHT. Epistaxis was the most common clinical presentation (38/42, 90%), followed by visceral AVMs (24/42, 57%) and telangiectasia (21/42, 50%). Five patients (12%) did not have a family history of HHT clinical symptoms. @*Conclusion@#. Only approximately half of patients with ACVRL1 or ENG genetic variants could be clinically diagnosed as having definite HHT, suggesting that genetic screening is important to confirm the diagnosis.
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BACKGROUND: Mesenchymal stem cells (MSCs) may be useful for reducing graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The GVHD and a graft-versus-leukemia (GVL) effect are inversely related. We therefore wanted to determine whether MSCs can preserve the GVL effect following experimental allo-HSCT. METHODS: After non-myeloablative allogeneic hematopoietic stem cell transplantation (NM-HSCT) using C57BL/6 (H-2b)-->B6D2F1 (H-2b/d), some mice received donor lymphocyte infusion (DLI) for induction of GVL effects by virtue of complete chimerism (CC), while the other groups did not receive DLI with persistence of mixed chimerism (MC). All mice were inoculated subcutaneously with P815 tumor cells and were intravenously treated with either donor MSCs or diluents. RESULTS: Between the DLI-treated groups with CC, tumor-related deaths and tumor growths were comparable irrespective to the infusion of MSCs. On the contrary, among mice without DLI which showed MC, the administration of MSCs significantly delayed tumor-related deaths compared to those without the administration of MSCs (50-day percent survival, 54.5% vs. 18.1%, P=0.0225). In the MC animals, tumor growth seemed to be more delayed in the mice injected with MSCs than in the controls (P=0.09). Donor MSCs injection was associated with increased donor effector/memory CD62L- T cells in MC but not in CC. CONCLUSION: In spite of the observed immunosuppressive effects of donor MSCs, our results indicate that the GVL effects were not influenced by the injection of MSCs but that under a given condition such as MC, the injection of donor MSCs could result in enhanced GVL effects.
