Induction of suppressive allogeneic regulatory T cells via rabbit antithymocyte polyclonal globulin during homeostatic proliferation in rat kidney transplantation

Experimental studies have shown that rabbit antithymocyte polyclonal globulin (ATG) can expand human CD4+CD25++Foxp3+ cells (Tregs). We investigated the major biological effects of a self‐manufactured rabbit polyclonal anti‐rat thymoglobulin (rATG) in vitro, as well as its effects on different peripheral T‐cell subsets. Moreover, we evaluated the allogeneic suppressive capacity of rATG‐induced Tregs in an experimental rat renal transplant model. Our results show that rATG has the capacity to induce apoptosis in T lymphocyte lymphocytes as a primary mechanism of T‐cell depletion. Our in vivo studies demonstrated a rapid but transient cellular depletion of the main T cell subsets, directly proportional to the rATG dose used, but not of the effector memory T cells, which required significantly higher rATG doses. After rATG administration, we observed a significant proliferation of Tregs in the peripheral blood of transplanted rats, leading to an increase in the Treg/T effector ratio. Importantly, rATG‐induced Tregs displayed a strong donor‐specific suppressive capacity when assessed in an antigen‐specific allogeneic co‐culture. All of these results were associated with better renal graft function in rats that received rATG. Our study shows that rATG has the biological capacity immunomodulatory to promote a regulatory alloimmune milieu during post‐transplant homeostatic proliferation.     

Cytomegalovirus prevention strategies in seropositive kidney transplant recipients: an insight into current clinical practice

There is notable heterogeneity in the implementation of cytomegalovirus (CMV) prevention practices among CMV‐seropositive (R+) kidney transplant (KT) recipients. In this prospective observational study, we included 387 CMV R+ KT recipients from 25 Spanish centers. Prevention strategies (antiviral prophylaxis or preemptive therapy) were applied according to institutional protocols at each site. The impact on the 12‐month incidence of CMV disease was assessed by Cox regression. Asymptomatic CMV infection, acute rejection, graft function, non‐CMV infection, graft loss, and all‐cause mortality were also analyzed (secondary outcomes). Models were adjusted for a propensity score (PS) analysis for receiving antiviral prophylaxis. Overall, 190 patients (49.1%) received preemptive therapy, 185 (47.8%) antiviral prophylaxis, and 12 (3.1%) no specific intervention. Twelve‐month cumulative incidences of CMV disease and asymptomatic infection were 3.6% and 39.3%, respectively. Patients on prophylaxis had lower incidence of CMV disease [PS‐adjusted HR (aHR): 0.10; 95% confidence interval (CI): 0.01–0.79] and asymptomatic infection (aHR: 0.46; 95% CI: 0.29–0.72) than those managed preemptively, with no significant differences according to the duration of prophylaxis. All cases of CMV disease in the prophylaxis group occurred after prophylaxis discontinuation. There were no differences in any of the secondary outcomes. In conclusion, antiviral prophylaxis was associated with a lower occurrence of CMV disease in CMV R+ KT recipients, although such benefit should be balanced with the risk of late‐onset disease.     

Design features of the Avasimibe and Progression of coronary Lesions assessed by intravascular UltraSound (A-PLUS) clinical trial

Background Although statins have been shown to be beneficial in the management of hyperlipidemia and the reduction of cardiovascular morbidity and mortality, rates of major cardiovascular events remain high despite their use. Inhibition of the acyl coenzyme A: cholesterol acyltransferase (ACAT) enzyme in the arterial wall may prevent excess accumulation of cholesteryl esters in macrophages. In addition to ACAT inhibitor monotherapy, combination of a statin with an ACAT inhibitor may be a promising approach to further prevent the progression of atherosclerosis. Methods This report describes the design and methodologic features of a double-blind, randomized, placebo-controlled trial to assess the effect of the ACAT inhibitor avasimibe at 50-, 250-, and 750-mg daily dosages on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients receive background lipid-lowering therapy when necessary. The study population consists of patients with at least one 20% to 50% diameter stenosis in a coronary artery with a reference diameter of ≥2.5 mm. IVUS and coronary angiography are performed at baseline and repeated at 24 months. The primary study end point is the change from baseline in plaque volume in a 30-mm segment of the coronary artery assessed by 3-dimensional IVUS. Several other IVUS and angiographic end points are measured. Conclusions The Avasimibe and Progression of coronary Lesions assessed by intravascular UltraSound (A-PLUS) trial is among the first large imaging trials to use IVUS as a primary end point and assesses the effects of the ACAT inhibitor avasimibe on atherosclerosis progression. (Am Heart J 2002;144:589-96.)     

Evaluación multimodal de la degeneración estructural de válvulas percutáneas en el seguimiento a largo plazo

Introduction and objectivesWe assessed the long-term hemodynamic performance of transcatheter heart valve (THV) by paired transthoracic echocardiography (TTE), and the incidence, characteristics and factors associated with THV structural valve degeneration (SVD).MethodsA total of 212 patients who underwent transcatheter aortic valve replacement and had a potential follow-up > 5 years with at least 1 TTE ≥ 1-year postprocedure were included. All patients had a TTE at 1 to 5 years and 36 had another one at 6 to 10 years. SVD was defined as subclinical (increase > 10 mmHg in mean transvalvular gradient +  decrease > 0.3 cm² in valve area and/or new-onset mild or moderate aortic regurgitation) and clinically relevant (increase > 20 mmHg in mean transvalvular gradient + decrease > 0.6 cm² in valve area and/or new-onset moderate-to-severe aortic regurgitation). Fifteen patients had a transesophageal echocardiography at the time of SVD diagnosis, and 85 an opportunistic computed tomography examination at 1 (0.5-2) years.ResultsTransvalvular mean gradient increased and valve area decreased over time (P < .01). At 8 years of follow-up, SVD occurred in 30.2% of patients (clinically relevant: 9.3%). Transesophageal echocardiography revealed thickened and reduced-mobility leaflets in 80% and 73% of SVD cases, respectively. No baseline or procedural factors were associated with SVD. THV underexpansion (3.5%) or eccentricity (8.2%) had no impact on valve hemodynamics/SVD at follow-up.ConclusionsA gradual THV hemodynamic deterioration occurred throughout a 10-year period, leading to SVD in ～30% of patients (clinically relevant in < 10%). Leaflet morphology/mobility were frequently impaired in SVD cases, but THV geometry did not influence valve hemodynamics or SVD.     

Evaluación de la validez de las funciones SCORE de bajo riesgo y calibrada para población española en las cohortes FRESCO

Introduction and objectives

To assess the validity of the original low-risk SCORE function without and with high-density lipoprotein cholesterol and SCORE calibrated to the Spanish population.

In Vitro and In Vivo Efficacy of Amphotericin B Combined with Posaconazole against Experimental Disseminated Sporotrichosis

We evaluated the combination of posaconazole with amphotericin B in vitro and in a murine model of systemic infections caused by Sporothrix brasiliensis and Sporothrix schenckii sensu stricto. In vitro data demonstrated a synergistic effect, and although posaconazole alone was effective against sporotrichosis, efficacy in terms of survival and burden reduction was increased with the combination. This combination might be an option against disseminated sporotrichosis, especially when itraconazole or amphotericin B at optimal doses are contraindicated.