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The present study describes the case of a patient with refractory diabetic cystoid macular edema who underwent vitrectomy with en bloc removal of the cystoid lesion component. The current study also performed histopathological and immunohistochemical analyses of the cystoid lesion component to assess fibrin/fibrinogen and advanced glycation end-products (AGEs) immunoreactivity. A 69-year-old Japanese man presented with visual loss in the left eye due to residual cystoid macular edema (CME) refractory to anti-vascular endothelial growth factor therapy. Best-corrected visual acuity was 1.2 in the right eye (OD) and 0.5 in the left eye (OS). Fundus examination showed dot hemorrhages and hard exudates in the peri-macular region with pan-retinal photocoagulation scars in both eye. Swept-source optical coherence tomography revealed CME with slight hyperreflectivity in the cyst OS. A total of 3 months after the initial visit, pars plana vitrectomy was performed, and the translucent solidified component within the cystoid lesion was isolated. Histopathologically, the excised component was elliptical in shape, measuring 0.7x0.4 mm and exhibited homogeneous eosinophilic material without cellular components. No membranous structure was observed surrounding the component. Immunohistochemistry demonstrated that the tissue was positive for fibrin/fibrinogen and weakly positive for AGEs, but was negative for glial fibrillary acidic protein, type 1 collagen and receptor for AGEs. To the best of our knowledge, the present case report is the first to histopathologically examine the contents of refractory CME, and to immunohistochemically demonstrate that fibrin in diabetic CME may be post-translationally modified by AGEs. These results suggested that fibrin in CME may escape degradation by plasmin due to post-translational modifications. [ABSTRACT FROM AUTHOR]

Background: Peripheral pulmonary stenosis (PPS) is a condition characterized by the narrowing of the pulmonary arteries, which impairs blood flow to the lung. The mechanisms underlying PPS pathogenesis remain unclear. Thus, the aim of this study was to investigate the genetic background of patients with severe PPS to elucidate the pathogenesis of this condition., Methods and Results: We performed genetic testing and functional analyses on a pediatric patient with PPS and Williams syndrome (WS), followed by genetic testing on 12 patients with WS and mild-to-severe PPS, 50 patients with WS but not PPS, and 21 patients with severe PPS but not WS. Whole-exome sequencing identified a rare PTGIS nonsense variant (p.E314X) in a patient with WS and severe PPS. Prostaglandin I 2 synthase (PTGIS) expression was significantly downregulated and cell proliferation and migration rates were significantly increased in cells transfected with the PTGIS p.E314X variant-encoding construct when compared with that in cells transfected with the wild-type PTGIS -encoding construct. p.E314X reduced the tube formation ability in human pulmonary artery endothelial cells and caspase 3/7 activity in both human pulmonary artery endothelial cells and human pulmonary artery smooth muscle cells. Compared with healthy controls, patients with PPS exhibited downregulated pulmonary artery endothelial prostaglandin I 2 synthase levels and urinary prostaglandin I metabolite levels. We identified another PTGIS rare splice-site variant (c.1358+2T>C) in another pediatric patient with WS and severe PPS., Conclusions: In total, 2 rare nonsense/splice-site PTGIS variants were identified in 2 pediatric patients with WS and severe PPS. PTGIS variants may be involved in PPS pathogenesis, and PTGIS represents an effective therapeutic target.

Cryoglobulins are immunoglobulins that precipitate in cold conditions. Type I cryoglobulinemic vasculitis is associated with hematological malignancies. We herein report a case of steroid-resistant type 1 cryoglobulinemic vasculitis associated with monoclonal gammopathy of undetermined significance (MGUS) in a 47-year-old woman. By immunofixation of cryoglobulin, we found that the main component of cryoglobulin was the M protein due to MGUS, so treatment of MGUS was needed. Bortezomib+dexamethasone therapy resulted in a rapid decrease in cryoglobulin and improvement in the symptoms of cryoglobulinemic vasculitis. In refractory type I cryoglobulinemic vasculitis, treatment of the underlying gammaglobulinopathy should be considered.