Immunotherapy response evaluation with magnetic resonance elastography (MRE) in advanced HCC

Background

Currently, there are no imaging predictors of immunotherapy outcome in hepatocellular carcinoma (HCC). The study aim was to determine if stiffness changes measured by magnetic resonance elastography (MRE) can be a predictor of immunotherapy response in patients with advanced HCC.

Materials and methods

This was a prospective study of 15 patients with biopsy proven-advanced HCC treated with Pembrolizumab. All patients had liver MRE and liver biopsy at baseline and at 6 weeks of therapy. Change in HCC stiffness on MRE was compared with overall survival (OS), time to disease progression (TTP), and number of intratumoral CD3+ T lymphocytes. Analysis was performed using descriptive statistics and Spearman correlation (R); p-value < 0.05 was considered statistically significant.

Results

Nine patients were evaluable. Median age was 71 years (range, 54–78). Etiology of liver disease was HCV (n = 4), HBV (n = 1) and NASH (n = 4). Median OS and TTP were 44 weeks and 13 weeks, respectively. Average baseline HCC stiffness and change in HCC stiffness were 5.0 kPa and 0.12 kPa, respectively. In contrast, average non-tumor liver stiffness was 3.2 kPa, and did not significantly change at 6 weeks (p = 0.42). Average size of measured tumor and change in size were 4 cm and − 0.32 cm, respectively. Change in HCC stiffness at 6 weeks correlated significantly with OS (R = 0.81), and TTP (R = 0.88,p < 0.01). Abundance of intratumoral T lymphocytes on tumor biopsy correlated significantly with HCC stiffness (R = 0.79,p = 0.007).

Conclusion

Our pilot MRE data suggests early change in tumor stiffness may be an indicator of immunotherapy response in patients with advanced HCC.

Lentiviral delivery of short hairpin RNAs

In less than a decade after discovery, RNA interference-mediated gene silencing is already being tested as potential therapy in clinical trials for a number of diseases. Lentiviral vectors provide a means to express short hairpin RNA (shRNA) to induce stable and long-term gene silencing in both dividing and non-dividing cells and thus, are being intensively investigated for this purpose. However, induction of long-term shRNA expression can also cause toxicities by inducing off-target effects and interference with the endogenous micro-RNA (miRNA) pathway that regulates cellular gene expression. Recently, several advances have been made in the shRNA vector design to mimic cellular miRNA processing and to express multiplex siRNAs in a tightly regulated and reversible manner to overcome toxicities. In this review we describe some of these advances, focusing on the progress made in the development of lentiviral shRNA delivery strategies to combat viral infections.

Fever and neutropenia in pediatric hematopoietic stem cell transplant patients

The objective of this study was to identify patterns of fever and neutropenia in pediatric patients undergoing initial hospitalization for hematopoietic stem cell transplantation. A retrospective review of 75 HSCTs over a 4-year period at a single institution was performed, of which 68% were allogeneic and 32% were autologous. Stem cell sources included bone marrow (29%), PBSC (52%) and umbilical cord blood (16%). Fever occurred in 74 (98%) of the episodes. Unexplained fever (FUO) occurred in 43%. Bacteremia without an anatomic focus occurred in 29%, while CVC associated infections occurred in 17%. In 49% of transplants at least one blood culture was positive. The incidence of bacteremia was higher in allogeneic HSCTs (58%) than in autologous transplants (29%). Gram-positive bacteria accounted for 71% of the isolates. Lower rates of bacteremia were observed in patients receiving oral fluoroquinolone prophylaxis. The median duration of fever was 12.5 days and time to engraftment 14 days. Regression analysis demonstrated that duration of fever was strongly associated with time to engraftment, and that time to engraftment was associated with source of cells and number of CD34+ cells/kg administered. Recipients of autologous PBSC had the shortest durations of fever and time to engraftment, while recipients of allogeneic umbilical cord blood had the longest. Bone Marrow Transplantation (2000) 25, 59-65.