P3509Leukocyte derived tumour necrosis factor modulates cardiac function in health and disease

Purpose

Tumour necrosis factor alpha (TNFα) regulates both normal and pathophysiological cardiac function. The regulatory role of TNFα derived from different sources (leukocyte versus cardiac cells) in cardiac physiology is unclear. Deficiency of iRhom2 protein prevents circulating immune cells from shedding TNFα (and CD62L, an adhesion molecule essential for effective immune function). Here we investigated the role of leukocyte derived TNFα in constitutive cardiac function and after cardiac injury.

Methods

Adult iRhom2-deficient mice (KO) and wildtype (Wt) littermates, of both genders, underwent echocardiography to assess cardiac physiologic function at least 1 week before receiving a single dose of isoproterenol (300mg/kg IP) to induce cellular death in 10% of the cardiomyoctes [1]. Cardiac echocardiography was repeated 36 hours after isoproterenol. Peripheral and cardiac-resident leukocytes were phenotyped by flow cytometry and molecular markers of cardiac stress (atrial and brain natriuretic protein, ANP, BNP) and inflammation (NFkB) were quantified using RT-PCR.

Results

Peripheral leukocytes from iRhom2 KO mice failed to shed CD62L in response to isoproterenol induced cardiac injury (e.g. neutrophils CD62L Mean Fluorescence Intensity KO: 9149±4616, Wt: 972±558, p<0.0001, n=9). iRhom2-deficient mice had higher cardiac output at baseline (KO 23±2 mL/min, n=11) compared to their wildtype littermates (Wt 18±3 mL/min, n=9). Wild type mice increased contractility after isoproterenol (Wt ejection fraction: baseline 60±6%, isoproterenol 68±6%, n=8) whilst iRhom2-deficient mice were unable to (KO ejection fraction: baseline 66±9%, isoproterenol 61±5%, n=8). ANP and BNP mRNA were elevated in ventricular tissue of iRhom2-knockout mice after isoproterenol, when compared to naïve tissue (ANP 2ΔCT: 3x increase, BNP 2ΔCT: 1.6x increase) whereas only ANP was elevated in wildtypes (ANP 2ΔCT: 2.7x increase, BNP 2ΔCT: 0.9x increase). No difference in immune cell infiltration of ventricular cardiac tissue was observed (number of CD45+ cells KO: 3014±3482, Wt: 2555±1411, p=0.7, n=9) NFkB mRNA was upregulated at baseline (2ΔCT KO: 0.2±0.08, Wt: 0.1±0.09) suggesting constitutive cardiac inflammation in iRhom2-deficient mice.

Conclusions

Inability to shed CD62L and TNFα is associated with constitutive and acquired cardiac dysfunction in iRhom2-deficient mice. These data support the hypothesis that leukocyte-derived TNFα is required for maintaining cardiac function in health and disease.

Acknowledgement/Funding

National Institute of Academic Anaesthesia/Royal College of Anaesthetists/British Journal of Anaesthesia; National Institute for Health Research

P4684Differential right ventricular adaptation patterns to chronic pressure overload

Background

Right ventricular (RV) dysfunction is the most important prognostic factor in chronic pulmonary hypertension (PH), but its underlying mechanisms are unknown. Clinical observation and prior experimental work suggest that RV pressure overload is not the only cause since the degree of RV adaptation varies with similar RV end-systolic pressures.

Purpose

Our aim was to characterize serial RV adaptation by cardiac magnetic resonance (CMR) in 3 different experimental large-animal models of increased afterload: a model of chronic postcapillary PH, a model of PH secondary to systemic-to-pulmonary shunt and a model of mechanical RV pressure overload (generated by pulmonary artery [PA] banding).

Methods

Four-week old piglets underwent pulmonary vein banding surgery to generate the chronic postcapillary PH model (n=20), aorto-pulmonary shunt (n=6), PA banding (n=7) or sham operation (n=7). They were followed up monthly with CMR and right heart catheterization (RHC). All procedures followed the “Principles of laboratory animal care”. Comparison of continuous variables among groups was performed with Mann-Whitney U test.

Results

Animals with either postcapillary PH or PH secondary to aorto-pulmonary shunt presented significant RV dilatation, hypertrophy and dysfunction that was maintained during follow-up (median RV end-systolic volume [RVESV]=32.6 ml/m2 for postcapillary PH and 32.6 ml/m2 for shunt vs. 16.1 ml/m2 in sham controls; median RV ejection fraction [RVEF]=61.5% for postcapillary PH and 60.5% for shunt vs. 69.6% in sham controls at the end of follow-up). Animals with PA banding also presented with significant RV dilatation and hypertrophy at the first month follow-up, but unlike all other groups, they developed reverse RV remodeling from the second month onwards and maintained normal RV volumes and RVEF values until the end of follow-up despite having severe RV hypertrophy (RV mass 22.6 g/m2 in PA banding vs. 16.1 g/m2 in controls at the 4th month follow-up; Figure).

CMR parameters (median values).

Conclusion

In PH there is a maladaptive RV hypertrophy that is not present in a model of progressive RV pressure overload without alterations of the pulmonary circulation. Increased RV pressure overload alone does not fully explain PH-associated RV dysfunction. Further research is needed to clarify the underlying mechanisms of adaptive and maladaptive hypertrophy in PH.

Acknowledgement/Funding

The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence

P596Early markers of right ventricular involvement in experimental chronic postcapillary pulmonary hypertension

Background

In chronic pulmonary hypertension (PH), the main cause of death is right ventricular (RV) failure. However, the onset of RV dysfunction varies significantly among patients. Early recognition of RV maladaptation would be highly relevant.

Purpose

To identify cardiac magnetic resonance (CMR)-derived parameters affected in early stages of PH before the development of RV dysfunction.

Methods

Experimental chronic PH was generated by pulmonary vein banding in 76 pigs whereas 14 animals underwent sham operation. Animals were followed-up monthly with right heart catheterization (RHC) and immediate CMR for a maximum of 9 months. CMR exams included a T1-mapping sequence to quantify equilibrium-extracellular volume (ECV) at the RV insertion points. Pairs of RHC and CMR examinations were compared among controls and PH with normal RV ejection fraction (RVEF≥55%) or reduced (REVF<55%) using ANCOVA test with Bonferroni correction. All procedures followed the “Principles of laboratory animal care”.

Results

In the presence of PH confirmed by RHC and normal RVEF, the RV displays significant hypertrophy and increased myocardial native T1 and ECV, despite preserved ventricular dimensions and PA flow (Fig 1B). In advanced stages of the disease, RV-AP uncoupling and reduced PA pulsatility develop together with RV dilatation and failure (Fig 1C).

CMR parameters in sham and PH animals Sham controls (n=25 evaluations) PH with normal RVEF (n=155 evaluations) PH with low RVEF (n=70) RVEF (%) 62±5 61±4 47±8# RVEDV (mL/m2) 73±18 83±17 111±29# RVESV (mL/m2) 28±8 32±8 61±25# RV mass (g/m2) 17±4 23±5* 30±11# PA area (cm2/m2) 5.5±1.2 6.3±1.6 8.7±2.2# Native T1 anterior RVIP (ms) 983±75 1043±78* 1055±90# ECV anterior RVIP (%) 27±5 31±6* 36±7# Native T1 inferior RVIP (ms) 959±68 1022±71* 1032±99# ECV inferior RVIP (%) 25±5 31±6* 36±7# PA pulsatility (%) 29±6 27±7 21±3# Ea/Emax 40±16 47±11 97±65# RVEDV: RV end-diastolic volume; RVESV: RV end-systolic volume; RVIP: RV insertion point. *p<0.05 1 vs. 2; #1 vs. 3.

NativeT1: control, PH-normal RV, RV dysf

Conclusion

RV hypertrophy and ECV expansion are early mechanisms in RV adaptation to postcapillary PH, whereas ventricular and PA dilatation, RV-PA uncoupling and reduced pulsatility appear in more advanced stages concurring with systolic dysfunction.

Acknowledgement/Funding

The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence

Relationship between tumor-associated immune infiltrate and p16 staining over clinicopathological features in acral lentiginous melanoma

PURPOSE

This study aims to evaluate the association between composition of tumor-infiltrating lymphocytes (TIL) and expression of p16 in acral lentiginous melanoma (ALM), and their impact on prognosis.

MATERIALS AND METHODS

A cohort of 148 surgical pathology specimens of ALM was studied. TIL were evaluated by immunohistochemical detection of CD3 and CD8, along with CD20, CD4, CD68, and CD163 in a subset of 43 cases. p16 protein expression was also investigated in all the cases.

RESULTS

The median age was 66 years, median Breslow thickness was 6.0 mm, grade III TIL was found in 28.4% and lymph nodes were involved in 54.2%. Breslow thickness (p < 0.001), stage I-II (p < 0.001), negative lymph nodes (p < 0.001) and < 10% p16 (p = 0.01) were associated with longer survival. Grade III of TIL was associated with thinner Breslow thickness (p = 0.008) and lower mitosis (p = 0.047). A higher density of CD3 TIL was associated with male gender (p = 0.008), thinner Breslow thickness (p = 0.047), negative lymph node (p = 0.031), early stage (p = 0.046), and p16 nuclear expression of > 10% (p = 0.045). Higher CD8 TIL was associated with > p16 (p = 0.03). Survival analysis found that longer survival had a trend to be associated with high TIL (p = 0.090). Levels of CD3+ and CD8+ cells were correlated with those of CD4+, CD20+, CD68+ and CD163+ immune cells.

CONCLUSIONS

Higher levels of TIL tend to be associated with better overall survival in ALM. Loss of expression of p16 is associated with lower levels of CD3+ and CD8+ TIL, indicating a probable relationship between p16 and TIL immune response in ALM .

Prurigo pigmentosa in a fair-skinned European woman: Dramatic improvement with doxycycline

INTRODUCTION

Prurigo pigmentosa is a rare inflammatory, pruriginous skin disease seen predominantly in young Asian women, with average age of onset in the mid-20s.

OBSERVATION

A 25-year-old fair-skinned European woman presented with a two-year history of pruriginous skin lesions recurring fortnightly. The initial lesions were inflammatory papules, which first emerged on the back of the neck before spreading to the shoulders, below the breasts and the back. The papules resolved leaving a reticular hyperpigmented network that gradually worsened after each episode. The clinical presentation and histopathological findings were consistent with a diagnosis of prurigo pigmentosa. Doxycycline 200mg/day was initiated, with rapid resolution, absence of any further flare-ups and gradual regression of the reticular pigmentation.

DISCUSSION

Prurigo pigmentosa is a skin disease of stereotypical presentation marked by frequent inflammatory flare-ups involving the trunk that are followed by periods of remission with residual hyperpigmentation. Herein we report a case observed in a fair-skinned French female subject. It is important that dermatologists are able to recognize it and distinguish it from other forms of pruriginous papular dermatosis, owing to the dramatic efficacy of tetracyclines in controlling the inflammatory flares and in reducing the adverse aesthetic impact of hyperpigmentation.

Prevalence of hock, knee, and neck skin lesions and associated risk factors in dairy herds in the Maritime Provinces of Canada

Skin lesions are commonly seen in dairy herds and have been associated with animal-, environmental-, and management factors. These lesions are not only a welfare concern, but they also affect profitability. Three areas on the cattle were examined for skin lesions: the hock, knee, and neck. Previous Canadian studies estimating the prevalence of lesions and the risk factors associated with them have not included the Maritime Provinces. In this study, 73 herds in the Maritime Provinces were chosen voluntarily to participate, with both tiestalls (n = 33) and freestalls (n = 40) represented. Within each herd, 67 to 90% of the lactating cows were selected and assessed for potential animal-, environmental-, and management-based risk factors. If producers were aware of the potential risk factors, this could help them reduce the prevalence in their herd. Leg lesions were scored on a 4-point scale (0-3) based on hair loss, swelling, and scabs, with a lesion defined as a score of 2 or 3 on at least 1 hock or knee. Necks were scored on a 3-point scale (0-2), with a lesion defined as score 2. For freestalls, the prevalence (95% confidence interval) of hock lesions was 39% (29-49%), knee lesions was 14% (11-18%), and neck lesions was 1% (<1-2%). Similarly, for tiestalls the prevalence (95% confidence interval) of hock lesions was 39% (33-46%), knee lesions was 17% (13-22%), and neck lesions was 5% (3-8%). Due to differences in management and methods of assessment between facility types, tiestalls and freestalls were analyzed separately. Due to dichotomization of cows as having a skin lesion or not, random-effects multivariable logistic regression was used to determine the risk factors for each lesion and facility type. Several environmental-based measurements, such as the stall base, type and dryness of bedding, and type of milking parlor, were associated with leg lesions. An environmental-based measurement that was associated with neck lesions was the design of the feed rail barrier in freestalls and the dimensions of the tie rail in tiestalls. Animal-based risk factors, such as stage of lactation, parity, and body condition, were also associated with all 3 types of lesions. This study showed that lesions to the hock, knee, and neck were common in the Maritime Provinces of Canada. Although differences were seen between facility types, in general, the results suggest that improving stall design and management and feed bunk design would help producers reduce the number of skin lesions seen in dairy cattle.

Prevalence of lameness and associated risk factors on dairy farms in the Maritime Provinces of Canada

Lameness in dairy cattle is a major issue for the industry due to the effects on the welfare of the animal, the economic impact, and consumer perception. The aim of this study was to determine the prevalence of lameness and explore potential risk factors in the Maritime Provinces of Canada. Cows were scored for lameness and potential risk factors and were assessed in 46 freestall herds and 33 tiestall herds in Nova Scotia, New Brunswick, and Prince Edward Island. In freestall herds, lameness was assessed using the most common method, locomotion scoring. A cow with a gait score of ≥3 out of 5 was considered to be lame. In tiestall herds, lameness was assessed using an alternative method known as stall lameness scoring. This assessment consisted of observation of the cow for 4 behavioral changes: standing on the edge of the stall, shifting weight, resting a limb, and uneven weight bearing when moved side to side. A cow displaying 2 or more of these behaviors was considered to be lame. At the time of the assessment, other animal-, environmental-, and management-based measurements were collected. These measurements were used in multivariable logistic regression analysis to determine risk factors that were associated with lameness for both freestalls and tiestalls independently. The prevalence of lameness was 21% for freestall-housed cattle and 15% for tiestall-housed cattle. Of the 1,488 tiestall-housed cows that were assessed, 68% showed no behavioral changes, whereas 15, 15, 2, and <1% showed 1, 2, 3, or 4 changes, respectively. In freestalls, higher odds of lameness were seen when cows spent ≥3 h/d in the holding area for milking compared with those that spent <3 h/d. In tiestall herds, higher odds of lameness were seen when bedding material was wet compared with when it was dry. For both lactating cow facility types, housing the dry cows and heifers on a deep bedded pack compared with tiestalls or freestalls was associated with a decreased odds of lameness. There were also many cow-level variables associated with lameness, including parity, daily milk production, stage of production, body condition, and width at the tuber coxae (hook bones). If producers become aware of the risk factors associated with lameness, they can make informed decisions on where to implement changes to help reduce the level of lameness in their herd.

Diversity, distribution and parasitism rates of fleas (Insecta: Siphonaptera) on sigmodontine rodents (Cricetidae) from Argentinian Patagonia

Fleas have great medical relevance as vectors of the causative agents of several diseases in animals and humans and rodents are the principal reservoirs for these pathogens. Argentinian Patagonia has the highest diversity of rodent fleas in South America. However, parasitism rates of rodents by fleas, the factors that influence them and the ecological aspects that modulate geographical distributions of flea-host association remain unknown for this region. This is the first study to record the diversity, prevalence, abundance, geographical distributions and host ranges of fleas in Argentinian Patagonia. It also compares parasitism rates among Patagonian ecoregions and host species. We captured 438 rodents belonging to 13 species, which harboured 624 fleas from 11 species and subspecies (P = 46%; mean abundance = 1.44). The high parasitism rates obtained were consistent with previous records for other arid regions, suggesting that Patagonia favours the survival and development of Siphonaptera. Host geographic range and abundance were related to the parasitological indexes: host species with high-density populations had the highest mean flea abundance and prevalence, whereas widely distributed hosts had the highest richness and diversity of flea species. Our results contribute to the knowledge of the flea-host-environment complex. Our analysis of flea distributions and parasitism rate in Central Patagonia may be useful in epidemiological studies of flea-borne diseases and provide a basis for implementing surveillance systems for better risk assessment of emerging zoonoses in the region.

Prognostic implications of residual disease tumor-infiltrating lymphocytes and residual cancer burden in triple-negative breast cancer patients after neoadjuvant chemotherapy

BACKGROUND

For primary triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), higher pretreatment tumor-infiltrating lymphocytes (TILs) correlates with increased pathologic complete response (pCR) rates, and improved survival. We evaluated the added prognostic value of residual disease (RD) TILs to residual cancer burden (RCB) in predicting survival post-NAC.

PATIENTS AND METHODS

We combined four TNBC NAC patient cohorts who did not achieve pCR. RD TILs were investigated for associations with recurrence-free survival (RFS), and overall survival (OS) using Cox models with stromal TILs as a continuous variable (per 10% increment). The likelihood ratio test was used to evaluate added prognostic value of RD TILs.

RESULTS

A total of 375 RD TNBC samples were evaluable for TILs and RCB. The median age was 50 years, with 62% receiving anthracycline/taxane chemotherapy. The RCB class after NAC was 11%, 50%, and 39% for I, II, and III, respectively. The median RD TIL level was 20% (IQR 10-40). There was a positive correlation between RD TIL levels and CD8+ T-cell density (ρ = 0.41). TIL levels were significantly lower with increasing post-NAC tumor (P = 0.005), nodal stage (P = 0.032), but did not differ by RCB class (P = 0.84). Higher RD TILs were significantly associated with improved RFS (HR: 0.86; 95% CI 0.79-0.92; P < 0.001), and improved OS (HR: 0.87; 95% CI 0.80-0.94; P < 0.001), and remained significant predictors in multivariate analysis (RFS P = 0.032; OS P = 0.038 for OS). RD TILs added significant prognostic value to multivariate models including RCB class (P < 0.001 for RFS; P = 0.021 for OS). The positive prognostic effect of RD TILs significantly differed by RCB class for RFS (PInt=0.003) and OS (PInt=0.008) with a greater magnitude of positive effect observed for RCB class II than class III.

CONCLUSIONS

TIL levels in TNBC RD are significantly associated with improved RFS and OS and add further prognostic information to RCB class, particularly in RCB class II.

Knowledge of tuberculosis and vaccine trial preparedness in Lima, Peru

SETTING

A safe, effective vaccine would improve tuberculosis (TB) control worldwide. Extensive community engagement will be essential to ensure the interest and participation of populations at highest risk.

OBJECTIVE/METHOD

To inform the potential implementation of efficacy studies, we assessed TB knowledge, attitudes towards licensed vaccines and willingness to participate in future TB vaccine efficacy trials among 262 household contacts of 79 recently diagnosed pulmonary TB cases in Lima, Peru.

RESULTS

Overall knowledge of TB was low. Only 41.6% of household contacts perceived themselves as being at high risk of acquiring TB. Slightly above half (54.2%) indicated willingness to participate in a TB vaccine trial. After clustered analysis adjusting for homogeneity among families, willingness to enroll was associated with belief that receiving all recommended vaccinations is important (adjusted OR [aOR] 3.28, P = 0.016), desire to know more about TB risk factors and clinical trials (aOR 2.60, P = 0.004), older age (aOR 1.02, P = 0.027) and TB knowledge (aOR 0.05, P = 0.039).

CONCLUSION

Barriers to participation in TB vaccine trials exist among individuals at high risk for TB. Targeted education about TB risk factors, TB transmission and education about the clinical trial process will be critical for laying the groundwork for future vaccine trials.