Donor-derived Cell-free DNA Shows High Sensitivity for the Diagnosis of Pancreas Graft Rejection in Simultaneous Pancreas-kidney Transplantation

BACKGROUND

Pancreas graft status in simultaneous pancreas-kidney transplant (SPKTx) is currently assessed by nonspecific biochemical markers, typically amylase or lipase. Identifying a noninvasive biomarker with good sensitivity in detecting early pancreas graft rejection could improve SPKTx management.

METHODS

Here, we developed a pilot study to explore donor-derived cell-free DNA (dd-cfDNA) performance in predicting biopsy-proven acute rejection (P-BPAR) of the pancreas graft in a cohort of 36 SPKTx recipients with biopsy-matched plasma samples. dd-cfDNA was measured using the Prospera test (Natera, Inc.) and reported both as a fraction of the total cfDNA (fraction; %) and as concentration in the recipient's plasma (quantity; copies/mL).

RESULTS

In the absence of P-BPAR, dd-cfDNA was significantly higher in samples collected within the first 45 d after SPKTx compared with those measured afterward (median, 1.00% versus 0.30%; median, 128.2 versus 35.3 cp/mL, respectively with both; P  = 0.001). In samples obtained beyond day 45, P-BPAR samples presented a significantly higher dd-cfDNA fraction (0.83 versus 0.30%; P  = 0.006) and quantity (81.3 versus 35.3 cp/mL; P  = 0.001) than stable samples. Incorporating dd-cfDNA quantity along with dd-cfDNA fraction outperformed dd-cfDNA fraction alone to detect active rejection. Notably, when using a quantity cutoff of 70 cp/mL, dd-cfDNA detected P-BPAR with a sensitivity of 85.7% and a specificity of 93.7%, which was more accurate than current biomarkers (area under curve of 0.89 for dd-cfDNA (cp/ml) compared with 0.74 of lipase and 0.46 for amylase).

CONCLUSIONS

dd-cfDNA measurement through a simple noninvasive blood test could be incorporated into clinical practice to help inform graft management in SPKTx patients.

Systematic review and network meta-analysis of clinical outcomes associated with isavuconazole versus relevant comparators for patients with invasive aspergillosis

OBJECTIVES

Voriconazole, amphotericin B (AmB) formulations, and isavuconazole are all included in guideline recommendations for treatment of patients with invasive aspergillosis (IA) but the relative efficacy of isavuconazole versus AmB formulations has not been directly compared. We aimed to estimate the relative efficacy of isavuconazole compared with AmB deoxycholate (AmB-D), liposomal AmB (L-AmB), and voriconazole for the treatment of patients with proven/probable IA.

METHODS

Nine literature databases were screened for randomized controlled trials comparing treatments with any of voriconazole, AmB-D, L-AmB and isavuconazole for treatment of proven/probable IA. Articles meeting the criteria were included in a meta-analysis to determine the efficacy of AmB-D, L-AmB and voriconazole relative to isavuconazole based on all-cause mortality (ACM) and overall response using a fixed-effects model.

RESULTS

Four articles were identified that compared L-AmB with AmB-D (Study 1), standard-dose L-AmB (3-5 mg/kg/day) with high-dose L-AmB (10 mg/kg/day; Study 2), voriconazole with AmB-D (Study 3), and isavuconazole with voriconazole (Study 4). In the network meta-analysis, isavuconazole was statistically superior to AmB-D on both ACM (odds ratio [95% credible intervals] shown as natural log, 1.00 [0.26, 1.74]) and overall response (-1.39 [-2.21, -0.63]). Differences between isavuconazole, and standard-dose L-AmB, high-dose L-AmB and voriconazole were not statistically significant for either ACM (0.18 [-1.17, 1.53], 0.50 [-1.11, 2.13] and 0.32 [-0.19, 0.84], respectively) or overall response (-0.99 [-2.21, 0.29], -0.89 [-2.41, 0.65] and 0.06 [-0.43, 0.57], respectively).

CONCLUSIONS

This data suggests that the efficacy of isavuconazole for treatment of IA is superior to AmB-D and comparable with both L-AmB and voriconazole.

The cost of treating mucormycosis with isavuconazole compared with standard therapy in the UK

AIM

Mucormycosis is a fungal infection associated with high mortality. Until recently, the only licensed treatments were amphotericin B (AMB) formulations. Isavuconazole (ISAV) is a new mucormycosis treatment. A UK-based economic model explored treatment costs with ISAV versus liposomal AMB followed by posaconazole.

MATERIALS & METHODS

As a matched case-control analysis showed similar efficacy for ISAV and AMB, a cost-minimization approach was taken. Direct costs - drug acquisition, monitoring and administration, and hospitalization costs - were estimated from the National Health Service perspective.

RESULTS

Per-patient costs for ISAV and liposomal AMB + posaconazole were UK£26,810 and UK£41,855, respectively, with savings primarily driven by drug acquisition and hospitalization costs.

CONCLUSION

ISAV may reduce costs compared with standard mucormycosis therapy.

Do patient characteristics influence efficacy and renal outcomes in liver transplant patients receiving everolimus?

Data from the 24-month randomized, multicenter, open-label H2304 study in 719 de novo liver transplant recipients were analyzed to evaluate the influence of variables potentially affecting immunological or renal response: recipient age, gender, end-stage disease, hepatitis C virus (HCV) status, and Model for End-stage Liver Disease score and estimated glomerular filtration rate (eGFR) at randomization (day 30). Treated BPAR was similar between everolimus with reduced tacrolimus (EVR + Reduced TAC) vs. conventional tacrolimus-based therapy (TAC Control) in all subpopulations, with a trend to lower risk under everolimus with reduced tacrolimus (EVR + Reduced TAC) in patients < 60 yrs and HCV-negative recipients. Risk of graft loss or death was similar in both treatment groups for all subpopulations. The change in eGFR to month 24 showed a benefit for EVR + Reduced TAC vs. TAC Control in all subpopulations other than those with the lowest baseline eGFR (30 to < 55 mL/min/1.73 m(2)), with a significant difference in favor of EVR + Reduced TAC for younger recipients (< 60 yr), female patients, HCV-negative patients and those with baseline eGFR of 55 to < 70 mL/min/1.73 m(2). Everolimus with reduced tacrolimus maintains efficacy to at least two yr after liver transplantation even in patients with risk factors for rejection, with particular renal benefits in specific patient subpopulations.

Localisation of endothelin like immunoreactivity in adult and developing human gut

The distribution of immunoreactivity for the potent vasoconstrictor endothelin-1 was studied in adult and developing human gut using antisera to endothelin-1 (1-21) and the C terminus of big endothelin-1. The coexistence of these peptides with other neuropeptides was investigated using comparative immunocytochemistry. Endothelin-1 like immunoreactivity was detected in extracts of adult (range 20-60 fmol/g wet weight) and fetal (33 fmol/g) gastrointestinal tract and was shown by chromatography to be the predominant isoform of endothelin present in both. It was localised by immunocytochemistry to ganglion cells in the submucous and myenteric plexuses and to scattered nerves, whereas big endothelin-1 like immunoreactivity was found in the submucous plexus only. Colocalisation studies showed immunoreactivity for both endothelin-1 and vasoactive intestinal peptide in the same ganglion cells of the submucous plexus. Although endothelin-1 immunoreactivity was not detected by immunocytochemistry in the fetal human gut until the 32nd week of gestation, big endothelin-1 was found as early as 11 weeks in the developing neural structures and epithelial cells. The latter were shown to be endocrine cells by their immunoreactivity for chromogranin. Our results indicate that endothelin is a neuropeptide found in adult human gut which shows transient expression in endocrine cells during development.

Localization of endothelinlike immunoreactivity and endothelin binding sites in human colon

The potent vasoconstrictor endothelin was originally isolated from vascular endothelial cells but has since been found in several other tissues. The aim of this study was to establish whether endothelinlike immunoreactivity occurs in human enteric nerves and to identify endothelin binding sites using immunocytochemical and in vitro autoradiographic techniques. Endothelinlike immunoreactivity was localized to nerve bundles throughout the colon and to most of the ganglion cells of the two major plexuses, many of which costored vasoactive intestinal polypeptide. High-affinity (dissociation constant = 0.35 +/- 0.014 nmol/L; mean +/- SEM) binding sites for endothelin 1, with an apparent binding capacity of 92 +/- 6.3 amol/mm2 (mean +/- SEM), were demonstrated in the myenteric plexus, with less dense binding being found in the submucous plexus, mucosa, muscle layers, and blood vessel walls. Competition data suggested two populations of binding sites, both showing high affinities for endothelins 1 and 2, vasoactive intestinal constrictor, and sarafatoxin b but differentiated by their affinity for endothelin 3 and sarafatoxin c. This study provides evidence that endothelin is a neuropeptide in the human intestine with binding sites on neural plexuses and mucosa, suggesting a role in the modulation of intestinal motility and secretion.