Nguyen, Justin H.

BACKGROUND AND OBJECTIVES: Stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs) can cause radiation-induced changes (RIC), but its interactions with AVM embolization are not well established. The aim of this study was to assess the effect of previous embolization on RIC in SRS-treated AVM patients. METHODS: Data of AVM patients treated with single-session SRS from 1987 to 2018 were retrieved from the International Radiosurgery Research Foundation. Univariable and stepwise backward logistic regression models were used to identify RIC predictors. Patients were stratified into those who received pre-SRS embolization (E + SRS) vs those who did not (SRS-only). Radiologic RIC (rRIC) was the primary end point. Secondary outcomes included symptomatic RIC (sRIC) and permanent symptomatic RIC (pRIC). RESULTS: Among 1187 AVM patients, the mean age was 36.4 years (SD 16.8), with 50.4% female patients. AVMs had a mean untreated AVM volume of 5.2 cm 3 . A total of 130 patients (11%) underwent neoadjuvant embolization (E + SRS). The overall rRIC and sRIC rates were 32.8% and 12.1%, respectively, with time to rRIC and sRIC being significantly longer in the E + SRS vs SRS-only cohorts (103.6 ± 339.4 vs 11.3 ± 12.5 and 60.4 ± 262.9 vs 9.5 ± 9.0 months, respectively). Seizures at presentation and ≥3-cm untreated AVM volume significantly correlated with a higher likelihood of rRIC (adjusted odds ratio [aOR] 2.32 [1.25-4.30] and aOR 2.77 [1.24-6.16], respectively). Age and pre-SRS embolization were associated with a significantly lower risk of rRIC (aOR 0.97 [0.96-0.99] and aOR 0.32 [0.13-0.74], respectively). The E + SRS cohort had significantly reduced odds of rRIC (aOR = 0.37 [0.15-0.89]) and pRIC (aOR = 0.04 [0.00-0.30]) after adjusting for significant covariates. CONCLUSION: Seizures at presentation and larger untreated AVM volume were independently associated with an increased risk of rRIC, whereas older age and pre-SRS embolization were protective. Notably, patients who underwent embolization before SRS had lower odds of rRIC and pRIC, with delayed onset of complications compared with SRS-only.

Abstract The highest risk for liver allograft rejection is within the first weeks to months after a liver transplant; however, while later-stage mechanisms are well described, the initial window at the moment of alloantigen influx (e.g., ~ 1 h post-reperfusion) remains unmapped. T-cell priming is initiated in lymph nodes, yet these sites are rarely profiled in humans and their relationship to rejection risk is unclear. To address this gap, we profiled paired pre- and ~ 1 h post-reperfusion hepatic draining lymph nodes from liver transplant recipients using multiplexed immunofluorescence and GeoMx whole-transcriptome profiling to identify features that predict rejection versus non-rejection. Early after reperfusion, CD4 + and CD8 + T cells became proximal to macrophages in rejection compared to dendritic cells in non-rejection, which also displayed an immunoregulatory-leaning profile marked by PD-1, IDO1, and CD39, suggesting that macrophages and dendritic cells differentially influence early T-cell alloimmunity. These results provide nodal targets for precise immune modulation.

Abstract Objectives Studies on the impact of hormone replacement therapy (HRT) on hepatocellular carcinoma (HCC) have been investigated in the past. This study aims to further address this topic using a large population dataset of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial (NIH, USA). Methods Multivariable logistic regression was used for the analysis of women in the entire PLCO cohort. Results A non-significant reduction in the risk of developing HCC was observed in women using HRT compared to never users (OR=0.61, 95 % CI: 0.21–1.79, p=0.367). Oral contraceptive use was significantly associated with reduced risk of HCC in the HRT group, (OR=0.17, 95 % CI: 0.00–0.82, p=0.028), and there was a nearly-significant interaction between HRT use and oral contraceptive use (p=0.054). Regardless of HRT use, those with pre-existing liver comorbidities of hepatitis or cirrhosis were at the highest risk of developing HCC (OR=5.09, 95 % CI: 1.13–22.81, p=0.034). However, liver comorbidities of hepatitis or cirrhosis and exposure to HRT showed a significant interaction (p=0.0001). Conclusions In those taking HRT, oral contraceptive use was significantly protective against HCC, suggesting that a longer period of hormone use (oral contraceptive plus HRT) provides additional protection against HCC than HRT alone. Overall, the low numbers of HCC diagnoses, which reflect the wider healthy female population, limited our ability to establish statistical significance regarding the impact of HRT on HCC incidence, which requires further prospective studies of larger populations.

Three multicenter studies have shown that the addition of mycophenolate mofetil (MMF) to an immunosuppressive regime consisting of cyclosporin A (CSA) and prednisone (PRED) decreases the incidence of acute rejection episodes when compared with azathioprine (AZA) or placebo (1–3). In those patients receiving 3 g/d of MMF, the highest dose used in the studies, there was a trend towards an increased incidence of cytomegaloviral sepsis (CMV). We postulated therefore that MMF may represent an independent risk factor for the development of CMV infection in patients receiving renal allografts and MMF at our institution. Having altered the triple drug regime from CSA, AZA (2‐2.5 mg/kg/d) and PRED to CSA. MMF (2 g/d) and PRED in July 1995, we elected to study all patients undergoing kidney transplantation for the 33‐month period January 1994‐September 1996, by undertaking a case control analysis to determine independent risk factors for the development of CMV infection, as defined by CMV viremia or tissue‐invasive CMV. Three CMV disease‐free control patients were matched to each case, these patients having been randomly selected from the entire pool of patients in the observation period. There were 31 CMV case patients and 102 control patients. Univariate analysis indicated that gender, a concomitant pancreas transplant, acute rejection and CMV seropositivity in the donor were risk factors. However, multivariate analysis indicated that only acute rejection and donor CMV seropositivity were independently linked (p<0.05) to CMV disease in this sample. Specifically, the odds ratio (OR) for CMV disease between MMF and AZA was 1.0 (95% confidence interval (CI): 0.46‐2.18). Therefore, in this case control study we find no evidence that MMF at a dose of 2 g/d is an independent risk factor for primary CMV viremia or tissue invasion in renal allograft recipients.

BACKGROUND AND OBJECTIVES: Stereotactic radiosurgery (SRS) with neoadjuvant embolization is a treatment strategy for brain arteriovenous malformations (AVMs), especially for those with large nidal volume or concomitant aneurysms. The aim of this study was to assess the effects of pre-SRS embolization in AVMs with an associated intracranial aneurysm (IA). METHODS: The International Radiosurgery Research Foundation AVM database from 1987 to 2018 was retrospectively reviewed. SRS-treated AVMs with IAs were included. Patients were categorized into those treated with upfront embolization (E + SRS) vs stand-alone SRS (SRS). Primary end point was a favorable outcome (AVM obliteration + no permanent radiation-induced changes or post-SRS hemorrhage). Secondary outcomes included AVM obliteration, mortality, follow-up modified Rankin Scale, post-SRS hemorrhage, and radiation-induced changes. RESULTS: Forty four AVM patients with associated IAs were included, of which 23 (52.3%) underwent pre-SRS embolization and 21 (47.7%) SRS only. Significant differences between the E + SRS vs SRS groups were found for AVM maximum diameter (1.5 ± 0.5 vs 1.1 ± 0.4 cm 3 , P = .019) and SRS treatment volume (9.3 ± 8.3 vs 4.3 ± 3.3 cm 3 , P = .025). A favorable outcome was achieved in 45.4% of patients in the E + SRS group and 38.1% in the SRS group ( P = .625). Obliteration rates were comparable (56.5% for E + SRS vs 47.6% for SRS, P = .555), whereas a higher mortality rate was found in the SRS group (19.1% vs 0%, P = .048). After adjusting for AVM maximum diameter, SRS treatment volume, and maximum radiation dose, the likelihood of achieving favorable outcome and AVM obliteration did not differ between groups ( P = .475 and P = .820, respectively). CONCLUSION: The likelihood of a favorable outcome and AVM obliteration after SRS with neoadjuvant embolization in AVMs with concomitant IA seems to be comparable with stand-alone SRS, even after adjusting for AVM volume and SRS maximum dose. However, the increased mortality among the stand-alone SRS group and relatively low risk of embolization-related complications suggest that these patients may benefit from a combined treatment approach.

In situ abdominal normothermic regional perfusion (A-NRP) has been used for liver transplantation (LT) with donation after circulatory death (DCD) liver grafts in Europe with excellent results; however, adoption of A-NRP in the United States has been lacking. The current report describes the implementation and results of a portable, self-reliant A-NRP program in the United States. Isolated abdominal in situ perfusion with an extracorporeal circuit was achieved through cannulation in the abdomen or femoral vessels and inflation of a supraceliac aortic balloon and cross-clamp. The Quantum Transport System by Spectrum was used. The decision to use livers for LT was made through an assessment of perfusate lactate (q15min). From May to November 2022, 14 A-NRP donation after circulatory death procurements were performed by our abdominal transplant team (N = 11 LT, N = 20 kidney transplants, and 1 kidney-pancreas transplant). The median A-NRP run time was 68 minutes. None of the LT recipients had post-reperfusion syndrome, nor were there any cases of primary nonfunction. All livers were functioning well at the time of maximal follow-up with zero cases of ischemic cholangiopathy. The current report describes the feasibility of a portable A-NRP program that can be used in the United States. Excellent short-term post-transplant results were achieved with both livers and kidneys procured from A-NRP.

Abstract Hepatocellular Carcinoma (HCC) and Cholangiocarcinoma (CCA) are the predominant forms of liver cancer, with a devastating combined incidence of 40,000 cases per year in the United States. Despite many differences between the cancers, liver transplant has found great success in treating both over traditional methods. However, up to 35% of patients’ cancer still recur within five years. Given the risk and resource intensiveness of this treatment, it is critical to identify factors that influence recurrence in these cancers. Previous studies have found the micro-environments of HCC tumors tend to be immune-active while those of CCA tumors tend to be immunosuppressive. Increased immune activity at the tumor level is associated with better patient outcomes, but the role and impact of the regional immune response in liver cancer is not well understood. Liver draining lymph node tissue was collected from patients undergoing orthotopic liver transplant (OLT) for HCC, CCA, or other reasons (control). Nanostring GeoMx Digital Spatial Profiler (DSP) was used to measure immune marker levelsWe found increased immune activity in the LNs of patients with HCC compared to CCA, showing significantly higher levels of lymphocytes and immune activity markers, matching previous tumor microenvironment findings. Additionally, comparing recurrent and non-recurrent HCC or CCA samples, we see generally increased immune activity in non-recurrent lymph nodes, also identifying specific immune markers in both cancer types that correlate with cancer recurrence or non-recurrence. These also reveal patterns of activity specific to both cancer type and recurrence status. Overall, this study provides novel insights into the regional immune response in liver cancers and identifies candidate proteins to serve as predictors of recurrence in liver cancer. We suggest CD163, CD66b, CD8, and CD56 as markers to predict post-OLT HCC recurrence and CD163, CD66b, ID01, and OX40L as candidate markers to predict post-OLT CCA recurrence using LN samples. Further spatial analysis of this data may further characterize immune activity in these lymph nodes, and future studies focusing on identified differences in immune activity may reveal factors affecting liver cancer aggressiveness and recurrence. Citation Format: Peyton Hickman, Aubrey E. Thompson, Justin Nguyen. The role of draining lymph nodes in the post-transplant recurrence of liver cancer: Examining immune response using spatial proteomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 624.

AbstractBackgroundThe aim of this study is to report the feasibility and short‐term outcomes of pancreaticoduodenectomy (PD) in patients who have undergone orthotopic liver transplantation (OLT).MethodsWe performed a retrospective review of a prospectively maintained pancreatic surgical database for all patients undergoing pancreaticoduodenectomy (PD) after liver transplant from January 1995 until June 2022. Demographics, indications for pancreatic resection, liver transplant and time from liver transplant to PD were reported. Operative mortality and morbidity were recorded within 90 days of surgery. Continuous variables were recorded as mean and range, while categorical variables were summarized using frequency and percentage. Postoperative complications within 90 days from PD were graded based on Clavien–Dindo classification with major complication recorded as grade IIIa or higher. Additionally, a comprehensive literature review was performed.ResultsA total of 916 patients who underwent PD at our institution between January 1995 and June 2022 were identified, and 9 patients had previous OLT. Five patients were females and 4 males with a mean age of 65 years (range 51–78). Average body mass index (BMI) was 30.8. Two patients had major complications, and three patients had minor complications. No clinically relevant POPF, PPH or DGE were observed. One patient died within 90 days from PD due to ischemic biliary pancreatic limb causing intrabdominal sepsis.ConclusionAlthough uncommon, PD after OLT is feasible with acceptable outcomes at high volume institutions and if performed by experienced surgeons.