Evaluation of current strategies for surveillance and management of donor-specific antibodies: Single-center study.

BACKGROUND: Although the presence of donor-specific antibodies (DSA) is known to impact lung allograft, limited data exist regarding DSA management. METHODS: We did a retrospective study at our center evaluating DSA management in adult lung transplant recipients undergoing lung transplantation between January 1, 2010 and June 30, 2014. Study follow-up was completed through October 2017. All recipients were stratified into 2 groups based on the presence or absence of DSA. Those with DSA were evaluated for the impact of treatment of DSA. The primary outcomes were postlung transplant survival and freedom from bronchiolitis obliterans syndrome (BOS), subset of chronic lung allograft dysfunction (CLAD). Simon-Makuch method was used to estimate overall survival and BOS-free survival to account for DSA as time-dependent covariate. Survival differences between the groups were analyzed using time-dependent Cox proportional hazards model. RESULTS: Sixty-four percent of 194 total subjects developed post-lung transplant DSA. Overall survival was different with worse survival in the DSA positive group that never cleared DSA (P = .002). BOS-free survival was lower, but did not reach significance in this group. Response to treatment was poor, with only 12 of 47 (25.5%) who received treatment demonstrating clearance of DSA. CONCLUSIONS: Donor-specific antibodies prevalence is high after lung transplantation. Clearance of DSA correlated with improved outcomes. Current therapeutic strategies against DSA are relatively ineffective. Multicenter collaborative studies will be required to evaluate current treatment strategies and other innovative modalities.

Hospital length of stay after lung transplantation: Independent predictors and association with early and late survival.

BACKGROUND: Duration of index hospitalization after lung transplantation (LTx) is an important variable that has not received much attention. We sought to determine independent predictors of prolonged hospital length of stay (LOS) and its association with early and late outcomes. METHODS: The United Network of Organ Sharing database was queried for adult patients undergoing LTx between 2006 and 2014 (N = 14,320). Patients with dual organ or previous transplantation and patients who died during the first 25 days after LTx were excluded (n = 12,647, mean age 55.2 years ± 13.1). Primary outcome was prolonged LOS (>25 days) (3,251/12,647; 25.7%). Donor, recipient, and procedure-related variables were analyzed as potential predictors of prolonged LOS. Association of prolonged LOS with 1-year and 5-year survival was evaluated using Cox proportional hazards analysis. RESULTS: Independent predictors of prolonged LOS included serum albumin, lung allocation score, functional status, and need of extracorporeal membrane oxygenation or ventilator support at the time of transplant; donor age >40 years; gender mismatch (female donor to male recipient); donor body mass index; African American ethnicity; ischemic time >6 hours; and double LTx. Prolonged LOS was independently associated with increased mortality at 1 year (hazard ratio, 3.96; 95% confidence interval, 3.48-4.50; p < 0.001) and 5 years (hazard ratio, 2.00; 95% confidence interval, 1.79-2.25; p < 0.001). CONCLUSIONS: A significant proportion of patients have a prolonged LOS after LTx, and several recipient, donor, and procedure-related variables are independent predictors of this outcome. Patients with prolonged LOS after LTx have significantly increased risk of death at 1 year and 5 years.

Contemporary analysis of incidence of post-operative atrial fibrillation, its predictors, and association with clinical outcomes in lung transplantation.

BACKGROUND: Atrial fibrillation (AF) is a common complication after lung transplantation (LT). Since the lung allocation score (LAS) was implemented in 2005, there has been significant evolution in the practice of LT, necessitating re-evaluation of this arrhythmia. METHODS: One hundred thirty-one patients undergoing LT between January 2011 and April 2013 were reviewed retrospectively to assess the occurrence of AF and its outcomes (mortality, morbidity measures, treatment strategies). Uni- and multivariate logistic regression models were constructed to ascertain predictors of AF. RESULTS: Forty-six patients (35.1%) developed post-operative AF at 4.65 ± 3.68 days post-LT. The AF group was older (60.07 vs 54.48 years, p = 0.01), and had higher rates of cardiopulmonary bypass (CPB) (73.33% vs 43.53%, p = 0.001). There was no difference in mortality, ICU length of stay (LOS) and ventilator days; however, the AF group had a significantly higher mean hospital LOS by 8.43 days (17.09 vs 25.52, p = 0.04). Age (OR = 1.04, p = 0.03) and CPB (OR = 3.68, p = 0.002) were identified as predictors of AF by stepwise logistic regression after adjusting for gender, history of AF, type of LT, pulmonary hypertension and LT indication. In the AF group, 78.26% of patients required combination therapy. Anti-arrhythmics were used in 52.17% of patients. Dofetilide/ibutilide use was not associated with increased mortality. A total of 97.82% were in sinus rhythm at discharge. CONCLUSIONS: To our knowledge, this is the first study to examine post-operative AF exclusively in the post-LAS era. Incidence of AF after LT is 35%. It increases hospital LOS, but not mortality. Management of AF is challenging and dofetilide/ibutilide serve as effective adjuncts to current therapy.

Study on alpha-amylase hydrolysis of potato amylopectin by a quartz crystal microbalance.

Potato amylopectin with phosphate groups was immobilized on a quartz crystal microbalance with dissipation monitoring (QCMD) using the attractive interaction between opposite charges, and enzymatic starch hydrolysis was monitored directly. Poly( L-lysine) (PLL) proved to be an appropriate cationic linker between the QCMD silica sensor and potato amylopectin. Increased mass and dissipation were observed when amylopectin was adsorbed onto the PLL layer and reversed when alpha-amylase was added. The effect of chitosan with cationic property on the hydrolysis of amylopectin was studied. Chitosan was observed to be adsorbed onto the amylopectin surface and to suppress hydrolysis by alpha-amylase. The formation of alternating layers of amylopectin and chitosan was monitored by QCMD. Amylopectin-chitosan trilayers increased resistance to digestion by alpha-amylase compared to one layer and to control without chitosan.

Extraction and characterization of Foeniculum vulgare pectins and their use for preparing biopolymer films in the presence of phaseolin protein.

Pectins from Foeniculum vulgare were extracted under acidic conditions. The obtained pectins were mainly composed of uronic acid but also contained traces of rhamnose, galactose, and arabinose. Extracted pectins were used as a carbohydrate source to prepare biopolymer films in the absence and in the presence of phaseolin protein. The swelling characteristics of the films were examined as a function of ionic strength, pH, and the applied osmotic stress. The swelling behavior was dominated by a Donnan-type effect, which decreases with increasing ionic strength and counterion valency. In all cases the swelling of films containing phaseolin was reduced, suggesting a network formation between protein and pectins. Mechanical property studies have also estimated the validity of the obtained novel biopolymer films in terms of mechanical resistance.

Deposition of pectin/poly-L-lysine multilayers with pectins of varying degrees of esterification.

The effect of pectin esterification on the assembly of multilayers consisting of poly-L-lysine (PLL) and pectin was studied using surface plasmon resonance (SPR), Fourier transform infrared-attenuated total reflection spectroscopy (FTIR-ATR), and a quartz crystal microbalance with dissipation monitoring (QCMD). With each layer deposited, there was a progressive increase in mass. The net charge of the multilayers was positive and increased with increasing degree of esterification of the pectin. Multilayer fabrication involved a limited fractionation of the pectin preparations, with the more highly esterified pectins having a weaker affinity for PLL. The multilayers were relatively hydrated structures with estimates of solids content in the range 10-32% w/w. The more highly esterified pectins had a tendency to form more hydrated structures, which showed a strong deswelling when PLL was added to a freshly deposited pectin layer.

Characterization of starch from tubers of yam bean (Pachyrhizus ahipa).

Detailed studies of the starch present in tubers of six accessions of Pachyrhizus ahipa (ahipa) have been carried out using starches from tubers of P. erosus (Mexican yam bean) and seeds of ahipa and wheat for comparison. Starch accounted for 56-58% of the tuber dry weight with granules occurring in a range of geometric forms and in sizes from below 5 microm to about 35 microm (mean about 10 microm in all accessions except two). The amylose content ranged from 11.6 to 16.8% compared with 16.9% in P. erosus tubers and over 23% in the seed starches. X- ray diffraction analysis showed A-type or C(A)-type diffraction patterns. The chain-length distribution of the amylopectin after enzyme debranching showed a peak at DP11 similar to that of wheat starch, but had a less marked shoulder at DP 21-22 and contained a higher proportion of longer chains. Differential scanning calorimitry showed an endothermic peak corresponding to gelatinization with T(max) ranging from 59 to 63 degrees C, which was similar to the T(max) of wheat (about 64 degrees C). The composition of the ahipa starch may mean that it is suitable for food applications that require low amylose content and low retrogradation after processing.