Faculty Bibliography

Background: The treatment paradigm of adult patients with acute lymphoblastic leukemia (ALL) is primarily derived from successful pediatric chemotherapy regimens. Pegasparagase (PEG) is a key component of pediatric therapy and is the backbone of cytotoxic ALL regimens. However, among the adult population the use of PEG has been limited by the difficulty in tolerating prolonged asparagine depletion. Hepatotoxicity is among the most common adverse events reported with the use of PEG, with grade 3/4 hepatotoxicity seen in 20% of young adults compared to 40-60% of older adults. Incorporating PEG into the treatment of ALL patients under 40 remains an accepted practice despite some studies that report up to 75% of patients have grade 3/4 adverse events as a result of asparagine depletion. In a study of 85 patients with ALL, 3-year overall survival (OS) was significantly different between patients older and younger than 35 (52% vs 83% p = 0.003). Whether this difference is due to PEG toxicity or to other factors remains to be determined. At NYU hospitals, PEG-containing protocols are frequently deployed to treat adult ALL. In our study, we sought to look at the difference in PEG toxicity and response rate (RR) in patients older and younger than 35 and whether these toxicities contributed to a delay in subsequent treatments and to a worse outcome. XXMethod(s): We conducted a retrospective chart review of patients older than 18 diagnosed with ALL or lymphoblastic lymphoma, who received at least 1 dose of PEG at our institution between 2014 and 2018. All patients received PEG as part of their first line treatment protocol. Our main objective was to compare the tolerability and toxicity profile of intravenous PEG in patients >=35 years old versus <35. Our secondary objective was to investigate its effects on chemotherapy delay, RR, and relapse rate. XX= 35 (46%). Mean age was 34.4 (Range: 18.9-63.1). The 2 groups shared similar distributions in gender, race, and Philadelphia chromosome (Ph) subtypes (Table 1). The older group received significantly less PEG, 5114.8 vs. 25353.7 units (p=0.0007) and 1.65 vs. 3.59 doses (p<0.0001) compared to the younger group. Grade 1-4 toxicity profiles were similar as both groups had high hepatotoxicity rates: transaminitis 100% vs. 89% (p=0.079) and hyperbilirubinemia 78% vs. 78% (p=0.104) in the older vs younger group, respectively. Grade 3-4 hepatotoxicity was significantly more pronounced in patients >=35 years old (transaminitis 65% vs. 33% [p=0.0245], hyperbilirubinemia 48 vs. 15% [p=0.0111]). Coagulopathy rates evaluated with hypofibrinogenemia and thrombosis were similar between the older and the younger groups at 52% vs. 44% [p=0.104] and 17% vs. 7%, [p=0.855], respectively, and the frequency of pancreatitis and anaphylaxis were 4% vs. 18.5% (p=0.422) and 0% vs. 14.8% (p=0.115), respectively. In the older group, only 13% completed the planned PEG dosages compared to 59% in the younger group (p=0.0008), and delay in other chemotherapy by more than 30 days due to PEG hepatotoxicity occurred in 55% of older patients compared to 22% of younger patients (p=0.02). MRD negativity rate after induction was similar in the older and younger group (50% vs. 60% [p=0.491], respectively), but the 12-month relapse free survival was significantly lower in the older group (41%, [95% CI: 55.7%-89%] vs. 77%, [95% CI: 21%-61%], p=0.022) (Figure 1). XXConclusion(s): Patients aged >= 35 received significantly less PEG during their treatments but were more likely to develop severe grade 3-4 hepatotoxicity compared to their younger counterparts. The response rates were similar with comparable MRD negativity rates after induction regardless of total amount of PEG administered. However, relapse occurred more frequently in the older group, possibly resulting from more frequent delays in administering other chemotherapy agents due to PEG toxicity. Incorporation of PEG is important in the treatment of ALL but should be used with caution in patients >=35 years old, and will likely require dose and schedule modifications. A larger prospective trial investigating adequate dosing and scheduling of PEG in this age group is warranted, specifically comparing delays in chemotherapy, relapse, and survival rates in regimens with and without PEG. [Formula presented] Disclosures: No relevant conflicts of interest to declare.XXCopyright

BACKGROUND:Activated vitamin D analog, paricalcitol, has been shown to attenuate the development of cardiac hypertrophy in Dahl salt sensitive (DSS) rats. To determine whether an antihypertrophic effect is class specific, we tested if doxercalciferol (a pro-hormone vitamin D2 analog) could also attenuate the development of cardiac hypertrophy in DSS rats. METHODS AND RESULTS/RESULTS:Male DSS rats were fed a high salt (HS) diet for 6 weeks beginning at 6 weeks of age. Doxercalciferol was administered intraperitoneally at 150 ng, 3 times per week (Monday, Wednesday, Friday) for 6 weeks. Pathological and echocardiographic findings demonstrated that rats on HS diet with doxercalciferol administration had significant decrease in cardiac hypertrophy and improved cardiac function compared to the HS + vehicle. In addition, there was a significant decrease in plasma brain natriuretic peptide (BNP) level and tissue atrial natriuretic factor (ANF) mRNA level with doxercalciferol treatment. Doxercalciferol also significantly reduced the level of protein kinase C-α (PKCα) suggesting that PKC-mediated cardiac hypertrophy may be associated with vitamin D deficiency. CONCLUSIONS:Administration of doxercalciferol attenuated the development of HS diet induced cardiac hypertrophy and cardiac dysfunction in DSS rats.

Exposure to tobacco smoke is known to have deleterious cardiovascular effects. In this study, we tested whether exposure to tobacco smoke exacerbates the severity of viral myocarditis in mice. Viral myocarditis was generated in 4-week-old male BALB/c mice by injection of Encephalomyocarditis virus (EMCV). Four groups were studied: (1) control (C, no smoke and no virus); (2) smoke only (S, exposure to cigarette smoke for 90 min/day for 15 days); (3) virus only (V); and (4) exposure to smoke for 5 days before plus 10 days following virus injection (S+V). We found that viral inoculation preceded by smoke exposure increased mortality more than twofold compared with virus inoculation alone. In addition, the mRNA level of atrial natriuretic factor was significantly higher in S+V than among any of the other 3 groups. Virus injection significantly decreased cardiac function compared with controls, with further deterioration observed in the S+V group. We also observed a significantly increased rate of apoptosis, with an increased activation of apoptosis-inducing factor in hearts exposed to S+V compared with those exposed to V alone. Our results suggest that preexposure to smoke significantly exacerbates the severity of viral myocarditis, likely through increased viral load and increased cardiomyocyte cell death.

AIMS/OBJECTIVE:The caspases are thought to be central mediators of the apoptotic program, but recent data indicate that apoptosis may also be mediated by caspase-independent mechanisms such as apoptosis-inducing factor (AIF). The role of AIF-induced apoptosis in heart, however, is currently not well understood. The aim of this study was to investigate the presence of and conditions for AIF-induced cardiac apoptosis in vitro. METHODS AND RESULTS/RESULTS:Hypertrophic cardiomyocyte (H-CM) cultures were prepared from the hearts of Dahl salt-sensitive rats fed a high salt diet. Apoptotic stimulation induced by hypoxia/reoxygenation or staurosporine (1 microM) enhanced AIF release in H-CMs compared with non-hypertrophic cardiomyocytes (N-CMs). Caspase inhibition using zVAD.fmk (25 microM) or overexpression of CrmA using recombinant adenovirus only partially protected N-CMs from apoptosis (63 +/- 0.93%) and provided no significant protection against apoptosis in hypertrophic cells (23 +/- 1.03%). On the other hand, poly-ADP-ribose polymerase inhibition using 4-AN (20 microM) during apoptotic stimulation blocked the release of AIF from mitochondria and significantly improved cell viability in hypertrophied cardiomyocytes (74 +/- 1.18%). CONCLUSION/CONCLUSIONS:A caspase-dependent, apoptotic pathway is important for N-CM death, whereas a caspase-independent, AIF-mediated pathway plays a critical role in H-CMs.