AB0307 MERKEL CELL CARCINOMA RECURRENCE RISK IS LOWER IN PATIENTS WITH AUTOIMMUNE DISEASE THAN IN THOSE WITH OTHER TYPES OF IMMUNE SUPPRESSION

Background

Merkel cell carcinoma (MCC) is twice as likely to recur in immunosuppressed (IS) patients as in immunocompetent (IC) patients. Iatrogenic IS due to autoimmune disease (AD) may influence prognosis differently than intrinsic IS such as due to hematologic malignancy. Moreover, modification of IS medication may improve prognosis.

Objectives

Our objective was to evaluate the risk of MCC recurrence among patients with AD diseases relative to other immunosuppressive conditions among 762 MCC patients from an Institutional review board-approved registry.

Methods

We categorized patients into 3 groups: IS due to AD (ISAD); IS from other causes (lSnon-AD) such as hematologic malignancy, solid organ transplant, human immunodeficiency virus; or immune competent (n=31, 70, and 661 respectively). ISAD patients were subcategorized into rheumatoid arthritis (RA) (ADRA, n=13) vs. AD except for RA (ADnon-RA, n=18). Descriptive statistics were used to compare the features of different characteristics in each group. Kaplan-Meier survival curves were constructed to assess the cumulative incidence of recurrence in different patient groups. In order to estimate the associations between baseline patient characteristics and the risk of MCC recurrence, Fine and Gray regression models were used with death as a competing risk for recurrence. The multivariable models adjusted for age, sex, and extent of MCC at initial presentation.

Results

Patients with ISAD had lower stage disease (local disease: 58% vs. 36%, p = 0.003) and smaller primary tumors than ISnon-AD (<= 2 cm: 83% vs. 57%, p=0.023). After adjusting for age, sex, and stage, ISAD patients (ADRA and ADnon-RA) overall had a 54% higher recurrence rate (hazard ratio (HR): 1.54, p=0.21) than IC patients. In comparison, ISnon-AD group had a 165% higher recurrence rate (HR: 2.65, p<0.001) than IC patients (Figure 1). When considered separately, ADRA pts appeared to have a similar recurrence rate as IC pts (HR: 1.19, p=0.76) while ADnon-RA pts had a higher recurrence rate (HR: 1.83, p=0.16) relative to IC pts. At the time of MCC diagnosis, 80% (n=24) of AD pts were on IS medication including conventional disease modifying drugs, biologics, or oral steroids. After MCC diagnosis, 22% (5 patients) stopped all immunosuppressive medications. Among patients on biologics, 89% (8/9 pts) elected to stop the drug. Eleven pts with AD experienced recurrences. Our study was underpowered to demonstrate associations regarding use of a particular immunosuppressive medication and MCC recurrence.

Figure 1.

Cumulative incidence of Merkel cell carcinoma recurrence in different patient groups.

AD = autoimmune disease; IS = immunosuppressed; RA = rheumatoid arthritis.There were 4/13, 8/18, 49/70, and 217/661 recurrences in the RA, ADnon-RA, other immunosuppressed, and not chronically immunosuppressed groups, respectively. Follow-up time ranged from 26 days to 16 years, with median follow-up times of 4.7 years, 1.6 years, 1.6 years, and 3.9 years for the RA, ADnon-RA, other immunosuppressed and not chronically immunosuppressed groups, respectively.

Conclusion

In this cohort, pts with AD appeared to have a better prognosis than intrinsic IS, with RA conferring very little risk above that for immune competent pts.

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

Effects of alirocumab on carotid plaque lipid content and inflammation: a time course study using serial vessel wall imaging

Background

PCSK9 inhibition has emerged as a potent pharmaceutical approach to lowering LDL cholesterol (LDL-C). Monoclonal anti-PCSK9 antibodies have been shown in recent clinical trials to reduce cardiovascular events in patients with atherosclerotic cardiovascular disease, but the underlying mechanisms are not fully understood. Meanwhile, circulatory inflammation markers were not reduced with PCSK9 inhibitors, thus their effects on plaque inflammation remain elusive. Vessel wall imaging with magnetic resonance (VW-MRI) has enabled serial monitoring of changes in carotid plaque lipid content and inflammation noninvasively that correlates with coronary and carotid vascular events.

Purpose

Using serial VW-MRI, we studied the effects and time course of PCSK9 inhibition with alirocumab on carotid plaque lipid content and inflammation.

Methods

Patients with LDL-C ≥70 mg/dl on ≤70 mg per week atorvastatin or an equivalent (due to statin intolerance or treating-physician discretion) and soft carotid plaque(s) identified on ultrasound underwent carotid VW-MRI. Those with confirmed lipid-rich plaque(s) on VW-MRI received alirocumab (150 mg subcutaneously every other week) and were re-scanned at 3, 6, and 12 months after treatment. Carotid VW-MRI included pre- and post-contrast images for measuring percent lipid-rich necrotic core volume (%LRNC) and dynamic contrast-enhanced images for measuring the extravasation rate of gadolinium contrast (Ktrans, reflecting tissue blood flow, endothelial surface area, and microvessel permeability), a marker of plaque inflammation. The co-primary endpoints were changes in %LRNC and Ktrans at 12 months from baseline.

Results

Of 31 patients enrolled, 27 completed the study (mean age: 69±9; male: 67%; on statins and/or ezetimibe: 41%; median LDL-C: 120 mg/dl [interquartile range: 99, 158]). Alirocumab induced a 59% reduction in LDL-C (p&lt;0.001) on average at 3 months to a median of 54 mg/dl (interquartile range: 29, 69), which was maintained at later time points. From 9.8% at baseline, %LRNC was progressively reduced to 8.4% at 3 months, 7.5% at 6 months, and 7.2% at 12 months, representing a rapid 14% reduction (p=0.032) at 3 months and a total reduction of 20% (p=0.019) at 12 months. From 0.07±0.02 min-1 at baseline, Ktrans was not reduced at 3 or 6 months but was significantly reduced by 17% (p=0.029) at 12 months to 0.06±0.02 min-1. No significant changes in lumen or wall area were observed during the study period.

Conclusions

Serial VW-MRI documented plaque-stabilizing effects of PCSK9 inhibition with alirocumab, including plaque delipidation and attenuation of plaque inflammation. The reduction in plaque lipid content was apparent as early as 3 months. The reduction in Ktrans was not seen until 12 months of treatment and may indicate a later effect on microvascular structure and/or function. This observation represents the earliest time course of plaque morphology modification by non-statin therapy reported to date.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): The study was funded by an investigator-initiated grant from Regeneron and Sanofi.

Pro- and anti-apoptotic activities of protozoan parasites

During infection, programmed cell death, i.e. apoptosis, is an important effector mechanism of innate and adaptive host responses to parasites. In addition, it fulfils essential functions in regulating host immunity and tissue homeostasis. Not surprisingly, however, adaptation of parasitic protozoa to their hosts also involves modulation or even exploitation of cell death in order to facilitate parasite survival in a hostile environment. During recent years, considerable progress has been made in our understanding of apoptosis during parasitic infections and there is now convincing evidence that apoptosis and its modulation by protozoan parasites has a major impact on the parasite-host interaction and on the pathogenesis of disease. This review updates our current knowledge on the diverse functions apoptosis may fulfil during infections with diverse protozoan parasites including apicomplexans, kinetoplastids and amoebae. Furthermore, we also summarize common mechanistic themes of the pro- and anti-apoptotic activities of protozoan parasites. The diverse and complex effects which parasitic protozoa exert on apoptotic cell death within the host highlight fascinating interactions of parasites and their hosts. Importantly, they also stress the importance of further investigations before the modulation of host cell apoptosis can be exploited to combat parasitic infections.