Platelets in Early Antibody-Mediated Rejection of Renal Transplants

Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.     

Cellular mechanisms of hereditary photoreceptor degeneration – Focus on cGMP

The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations.In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca²⁺-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca²⁺-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development.Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.     

Comparison between a new platelet count drop method PL-11, light transmission aggregometry,VerifyNow aspirin system and thromboelastography for monitoring short-term aspirin effects in healthy individuals

Platelet function has been described by many laboratory assays, and PL-11 is a new point-of-care platelet function analyzer based on platelet count drop method, which counts platelet before and after the addition of agonists in the citrated whole blood samples. The present study sought to compare PL-11 with other three major more established assays, light transmission aggregometry (LTA), VerifyNow? aspirin system and thromboelastography (TEG), for monitoring the short-term aspirin responses in healthy individuals. Ten healthy young men took 100?mg/d aspirin for 3-day treatment. Platelet function was measured via PL-11, LTA, VerifyNow and TEG, respectively. The blood samples were collected at baseline, 2 hour, 1 day during the aspirin treatment and 1 day, 5?±?1 days, 8?±?1 days after the aspirin withdrawal. Moreover, 90 additional healthy subjects were recruited to establish a reference range for PL-11. Platelet function of healthy subjects decreased significantly 2 hours after 100?mg/d aspirin intake and began to recover during 4–6 days after the aspirin withdrawal. Correlations between methods were PL-11 vs. LTA (r?=?0.614, p?<?0.01); PL-11 vs. VerifyNow (r?=?0.829, p?<?0.01); PL-11 vs. TEG (r?=?0.697, p?<?0.001). There was no significant bias between PL-11 and LTA at baseline (bias?=?1.94%, p?=?0.804) using Bland-Altman analysis, while the data of PL-11 were significantly higher than LTA (bias?=?24.02%, p?<?0.001) during the aspirin therapy. The reference range for PL-11 in healthy young individuals was from 66.8 to 90.5% (95%CI). When aspirin low-responsiveness was defined as LTA?>?20%, the cut-off values for each method were, respectively: PL-11?>?50%, VerifyNow?>?533 ARU, TEG?>?60.2%. The results of different platelet function assays were uninterchangeable for monitoring aspirin response and correlations among them were also varied. Correlations among PL-11 and other three major assays suggested the ability of PL-11 to assess the treatment effects of aspirin. But a large cohort study is needed to confirm the cut-off value of aspirin response detected by PL-11.     

新生儿高胆红素血症的临床治疗分析

目的探讨布拉氏酵母菌散治疗对新生儿高胆红素血症的临床疗效。方法在2018年1月—2019年1月期间,将医院诊治的110例新生儿高胆红素血症患儿纳入研究对象,按照治疗方法的不同,将患儿分成两组,采用常规蓝光照射治疗的患儿定为对照组,55例,在蓝光治疗基础上增加布拉氏酵母菌散治疗的患儿定为观察组,55例,对比两组患儿治疗的临床效果。结果观察组和对照组治疗的有效率分别为98.18%和87.27%,有统计学意义(P<0.05);治疗后3 d和1周,两组患儿的胆红素水平明显下降,且观察组患儿下降更加明显,与对照组相比差异有统计学意义(P<0.05);观察组患儿黄疸消退时间为(5.12±1.21)d,对照组患儿黄疸消退时间为(7.21±1.22)d,有统计学意义(P<0.05);观察组不良反应发生率为5.45%,明显低于对照组的12.73%,有统计学意义(P<0.05)。结论对新生儿高胆红素血症患儿在常规蓝光治疗的基础上增加布拉氏酵母菌散进行治疗,可以显著提高临床治疗效果。     

Terapia de luz pulsada intensa regulada: un tratamiento complementario prometedor para la enfermedad de ojo seco

ObjectiveTo propose the Intense Pulsed Light (IPL) therapy as a helpful supplementary treatment in patients with dry eye disease.Material and methodsRetrospective cross sectional design. Medical records of patients in whom dry eye disease symptoms were not satisfactorily controlled with medical therapy alone and who underwent additional IPL with at least three sessions completed. Data were analyzed before therapy and 3 weeks after its completion to asses improvement. Determination of symptoms, through a visual analog scale; tear film stability, through tear Break Up Time (tBUT); measurement of tear secretion, through Schirmer Test; and ocular surface staining with Van Bijsterveld score were evaluated. SPSS software and nonparametric analysis of repeated measures were used. The study was approved by the ethics committee.Results50 eyes from 25 subjects were reviewed. There were 9 males (36%) and 16 females (64%), with a median age of 59 years (IQR 52-64). The median of the symptoms scale was 8 (IQR 8-9) and 3 (IQR 2-4) before and after the therapy respectively (P < .05). The median of BUT was 4 (IQR 3-5) and 10 (IQR 8-11), Schirmer test was 13 (IQR 12-15) and 15 (IQR 13-20), and Van Bijsterveld score was 3 (RIC 3-4) and 2 (IQR 2-3) before and after the therapy respectively (P < .05, for all measurements).ConclusionIPL treatment has excellent results regarding both: dry eye disease symptoms improvement and in office objective tests such as tBUT, Schirmer test and Van Bijsterveld score; IPL could be considered as an effective adjunct for dry eye disease.