Diagnostic accuracy of prenatal ultrasound in coarctation of aorta: systematic review and individual participant data meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA).

METHODS

An individual participant data meta-analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally. MEDLINE, EMBASE and CINAHL were searched for studies published between January 2000 and November 2021. Inclusion criteria were fetuses with suspected isolated CoA, defined as ventricular and/or great vessel disproportion with right dominance on ultrasound assessment. Individual participant-level data were obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for extracting data, and the QUADAS-2 tool was used for assessing quality and applicability. The reference standard was CoA, defined as narrowing of the aortic arch, diagnosed after birth. The most commonly evaluated parameters on ultrasound, both in B-mode and on Doppler, constituted the index test. Summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and likelihood ratios were computed using the hierarchical summary receiver-operating-characteristics model.

RESULTS

The initial search yielded 72 studies, of which 25 met the inclusion criteria. Seventeen studies (640 fetuses) were included. On random-effects logistic regression analysis, tricuspid valve/mitral valve diameter ratio > 1.4 and > 1.6, aortic isthmus/arterial duct diameter ratio < 0.7, hypoplastic aortic arch (all P < 0.001), aortic isthmus diameter Z-score of < -2 in the sagittal (P = 0.003) and three-vessel-and-trachea (P < 0.001) views, pulmonary artery/ascending aorta diameter ratio > 1.4 (P = 0.048) and bidirectional flow at the foramen ovale (P = 0.012) were independently associated with CoA. Redundant foramen ovale was inversely associated with CoA (P = 0.037). Regarding diagnostic accuracy, tricuspid valve/mitral valve diameter ratio > 1.4 had a sensitivity of 72.6% (95% CI, 48.2-88.3%), specificity of 65.4% (95% CI, 46.9-80.2%) and DOR of 5.02 (95% CI, 1.82-13.9). The sensitivity and specificity values were, respectively, 75.0% (95% CI, 61.1-86.0%) and 39.7% (95% CI, 27.0-53.4%) for pulmonary artery/ascending aorta diameter ratio > 1.4, 47.8% (95% CI, 14.6-83.0%) and 87.6% (95% CI, 27.3-99.3%) for aortic isthmus diameter Z-score of < -2 in the sagittal view and 74.1% (95% CI, 58.0-85.6%) and 62.0% (95% CI, 41.6-78.9%) for aortic isthmus diameter Z-score of < -2 in the three-vessel-and-trachea view. Hypoplastic aortic arch had a sensitivity of 70.0% (95% CI, 42.0-88.6%), specificity of 91.3% (95% CI, 78.6-96.8%) and DOR of 24.9 (95% CI, 6.18-100). The diagnostic yield of prenatal ultrasound in detecting CoA did not change significantly when considering multiple categorical parameters. Five of the 11 evaluated continuous parameters were independently associated with CoA (all P < 0.001) but all had low-to-moderate diagnostic yield.

CONCLUSIONS

Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. However, diagnostic accuracy is only moderate, even when combinations of parameters are considered. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Local aromatase excess with recruitment of unusual promoters of CYP19A1 gene in prepubertal patients with gynecomastia

OBJECTIVES

Gynecomastia may be due to aromatase excess in several diseases such as obesity and cancer. Aromatase excess syndrome (AEXS) is an autosomal dominant disorder caused by overexpression of CYP19A1. Germinal mutations occurring in AEXS include various genomic rearrangements including duplication, deletion, and inversion identified in the upstream region of CYP19A1. Aromatase overexpression caused by a CYP19A1 somatic mutation has been rarely described.

METHODS

Breast adipose tissue biopsies or surgical specimens were obtained from 19 subjects with gynecomastia. Aromatase quantification was performed by digital PCR and CYP19A1 sequencing by RACE PCR products.

RESULTS

We observed localized aromatase overexpression (>10 fold greater than normal) in breast adipose tissue from three prepubertal males with gynecomastia out of the 19 cases. One carried a chromosomal rearrangement between CYP19A1 and DMXL2, consistent with AEXS. In the 2 others, the first exon of CYP19A1 contained 11 different tissue-specific promoter subtypes, specifically I.4 or I.3 normally expressed by adipose tissue, but also the placental I.2 promoter and the more ubiquitous I.7 which is usually expressed in breast cancer, uterine, and endothelial tissues. No differences in clinical or biochemical characteristics were observed between these 3 subjects and 16 others without aromatase overexpression.

CONCLUSIONS

We describe two cases of aromatase overexpression in breast adipose tissue associated with nonspecific promoter recruitment. Further investigations are necessary to understand the mechanisms involved in aberrant promoter selection.

Abstract B84: Decipher the role of IL-33 as an activator of NK cells’ antitumor activity

Interleukin (IL)-33 is an alarmin belonging to the IL-1 family. Through its receptor ST2, IL-33 promotes both type 1 and type 2 immune responses, depending on the type of responding cells and the microenvironment in damaged tissues. Consistently, paradoxical roles of IL-33 have been reported in the context of cancer. These observations prompted us to investigate i) the expression of IL-33/ST2 in breast tumors and ii) the role of IL-33/ST2 in NK cell activation in physiologic and tumor contexts. Using immunohistochemistry (IHC) and transcriptomic analyses, we observed that IL-33 is expressed at higher levels in ductal carcinoma in situ (DCIS) compared to invasive breast cancer (IBC), especially in the stroma and in luminal BC subtype. In situ, IL-33 was mainly detected in endothelial cells and at lower extent in scattered cells within the stroma of breast tumors. Furthermore, we unraveled a new pathway for NK cells’ activation where IL-12 upregulates ST2 on human NK cells, which in turn become responsive to IL-33 by secreting high levels of IFN-γ and increasing their cytotoxic activity. This effect was specific to a subset of human CD56dim NK cells (20%) and was dependent on STAT-4 phosphorylation. In mice, we also observed a strong activation of spleen NK cell by IL-33 in combination with IL-12 in vitro. Finally, using IL-33ko mice, preliminary results show a contribution of endogenous IL-33 in the prevention of experimental lung metastasis development following B16 iv injection in therapeutic settings using exogenous administration of IL-12. Following up on these results, our aim is now to i) better characterize IL-33-responsive NK cells subpopulation in blood, ii) understand why human CD56bright NK cells do not upregulate ST2 despite response to IL-12 by phosphorylating STAT-4, iii) characterize NK cells’ response to IL-33 in human breast tumors, iv) evaluate ST2 expression by immune cells infiltrating breast and ovarian tumors, and v) confirm the activating role of IL-33 on NK cells’ biology in tumor models in vivo. All together, our observations are in favor of an NK-mediated antitumor role of IL-33 that we are currently pursuing as a potential novel therapeutic strategy in cancer.

Citation Format: Anais Eberhardt, Elena Blanc, Emilie Lardenois, Sarah Renaudineau, Jennifer Herbulot, Benoit Dumont, Isabelle Durand, Emilie Charrier, Pauline Schmitt, Jean-Philippe Girard, Antoine Marçais, Thierry Walzer, Christophe Caux, Nathalie Bendriss-Vermare. Decipher the role of IL-33 as an activator of NK cells’ antitumor activity [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B84.

Netrin-1 promotes naive pluripotency through Neo1 and Unc5b co-regulation of Wnt and MAPK signalling

In mouse embryonic stem cells (mESCs), chemical blockade of Gsk3α/β and Mek1/2 (2i) instructs a self-renewing ground state whose endogenous inducers are unknown. Here we show that the axon guidance cue Netrin-1 promotes naive pluripotency by triggering profound signalling, transcriptomic and epigenetic changes in mESCs. Furthermore, we demonstrate that Netrin-1 can substitute for blockade of Gsk3α/β and Mek1/2 to sustain self-renewal of mESCs in combination with leukaemia inhibitory factor and regulates the formation of the mouse pluripotent blastocyst. Mechanistically, we reveal how Netrin-1 and the balance of its receptors Neo1 and Unc5B co-regulate Wnt and MAPK pathways in both mouse and human ESCs. Netrin-1 induces Fak kinase to inactivate Gsk3α/β and stabilize β-catenin while increasing the phosphatase activity of a Ppp2r2c-containing Pp2a complex to reduce Erk1/2 activity. Collectively, this work identifies Netrin-1 as a regulator of pluripotency and reveals that it mediates different effects in mESCs depending on its receptor dosage, opening perspectives for balancing self-renewal and lineage commitment.

A key process of the nonstationary relationship between ENSO and the Western Pacific teleconnection pattern

Recent studies have discovered an intriguing nonstationary relationship between El Ninõ-Southern Oscillation (ENSO) and the Western Pacific (WP) teleconnection pattern, one of the most prominent winter atmospheric circulation patterns in the North Pacific, with a regime-dependent interdecadal modulation of significant and insignificant correlations. However, the physical process underlying the observed nonstationary ENSO-WP relationship is a puzzle and remains to be elucidated, which is also essential for clarifying the still-debated nontrivial issue on whether the WP is directly forced by ENSO or by midlatitude storm tracks-driven intrinsic processes. Based on empirical orthogonal function (EOF) analysis of the upper-tropospheric teleconnection patterns and associated Rossby wave sources (RWS), we show that the nonstationarity in question is due to the regime-dependent constructive or destructive interference in meridional overturning circulation between the two leading EOFs of RWS best correlated with ENSO and WP, respectively. The observed insignificant correlation between ENSO and the WP after the 1988 regime shift can be explained by interrupted teleconnection between the tropics and high latitudes due to the collapse of the subtropical bridge pillar in the jet entrance region, consequence of the destructive interference. This suggested interference mechanism related to the regime-dependent upper-level RWS fields has significant implications for resolving the puzzle that hinders better understanding of decadal regime behaviors of the climate system in the North Pacific.

Autocrine Adenosine Regulates Tumor Polyfunctional CD73+CD4+ Effector T Cells Devoid of Immune Checkpoints

The production of CD73-derived adenosine (Ado) by Tregs has been proposed as a resistance mechanism to anti-PD-1 therapy in murine tumor models. We reported that human Tregs express the ectonucleotidase CD39, which generates AMP from ATP, but do not express the AMPase CD73. In contrast, CD73 defined a subset of effector CD4⁺ T cells (Teffs) enriched in polyfunctional Th1.17 cells characterized by expression of CXCR3, CCR6, and MDR1, and production of IL17A/IFNγ/IL22/GM-CSF. CD39⁺ Tregs selectively targeted CD73⁺ Teffs through cooperative degradation of ATP into Ado inhibiting and restricting the ability of CD73⁺ Teffs to secrete IL17A. CD73⁺ Teffs infiltrating breast and ovarian tumors were functionally blunted by Tregs expressing upregulated levels of CD39 and ATPase activity. Moreover, tumor-infiltrating CD73⁺ Teffs failed to express inhibitory immune checkpoints, suggesting that CD73 might be selected under pressure from immune checkpoint blockade therapy and thus may represent a nonredundant target for restoring antitumor immunity.Significance: Polyfunctional CD73⁺ T-cell effectors lacking other immune checkpoints are selectively targeted by CD39 overexpressing Tregs that dominate the breast tumor environment. Cancer Res; 78(13); 3604-18. ©2018 AACR.

A novel regulation of PD-1 ligands on mesenchymal stromal cells through MMP-mediated proteolytic cleavage

Whether fibroblasts regulate immune response is a crucial issue in the modulation of inflammatory responses. Herein, we demonstrate that foreskin fibroblasts (FFs) potently inhibit CD3⁺ T cell proliferation through a mechanism involving early apoptosis of activated T cells. Using blocking antibodies, we demonstrate that the inhibition of T cell proliferation occurs through cell-to-cell interactions implicating PD-1 receptor expressed on T cells and its ligands, PD-L1 and PD-L2, on fibroblasts. Dual PD-1 ligand neutralization is required to abrogate (i) binding of the PD-1-Fc fusion protein, (ii) early apoptosis of T cells, and (iii) inhibition of T cell proliferation. Of utmost importance, we provide the first evidence that PD-1 ligand expression is regulated through proteolytic cleavage by endogenous matrix metalloproteinases (MMPs) without transcriptional alteration during culture-time. Using (i) different purified enzymatic activities, (ii) MMP-specific inhibitors, and (iii) recombinant human MMP-9 and MMP-13, we demonstrated that in contrast to CD80/CD86, PD-L1 was selectively cleaved by MMP-13, while PD-L2 was sensitive to broader MMP activities. Their cleavage by exogenous MMP-9 and MMP-13 with loss of PD-1 binding domain resulted in the reversion of apoptotic signals on mitogen-activated CD3⁺ T cells. We suggest that MMP-dependent cleavage of PD-1 ligands on fibroblasts may limit their immunosuppressive capacity and thus contribute to the exacerbation of inflammation in tissues. In contrast, carcinoma-associated fibroblasts appear PD-1 ligand-depleted through MMP activity that may impair physical deletion of exhausted defective memory T cells through apoptosis and facilitate their regulatory functions. These observations should be considered when using the powerful PD-1/PD-L1 blocking immunotherapies.

[Total isolated anomalous pulmonary venous return: Are there any clues for prenatal screening?]

Total anomalous pulmonary venous connection (TAPVC) is a serious congenital anomaly. TAPVC with obstruction of pulmonary venous return is an emergency requiring urgent intervention. Before 2010, very few isolated TAPVC were diagnosed prenatally. It has been suggested in the past literature that the use of Color flow Doppler is particularly useful for the screening of TAPVC prenatally. In fact, although color-Doppler is often useful to confirm a TAPVC diagnosis, it can be quite misleading in the screening process of the condition. Looking at data of missed TAPVC, we describe how to identify TAPVC during routine cardiac screening. Since 2010, our isolated TAPVC prenatal diagnosis rate is more than 40%.

Human natural killer cells promote cross-presentation of tumor cell-derived antigens by dendritic cells

Dendritic cells (DCs) cross-present antigen (Ag) to initiate T-cell immunity against most infections and tumors. Natural killer (NK) cells are innate cytolytic lymphocytes that have emerged as key modulators of multiple DC functions. Here, we show that human NK cells promote cross-presentation of tumor cell-derived Ag by DC leading to Ag-specific CD8(+) T-cell activation. Surprisingly, cytotoxic function of NK cells was not required. Instead, we highlight a critical and nonredundant role for IFN-γ and TNF-α production by NK cells to enhance cross-presentation by DC using two different Ag models. Importantly, we observed that NK cells promote cell-associated Ag cross-presentation selectively by monocytes-derived DC (Mo-DC) and CD34-derived CD11b(neg) CD141(high) DC subsets but not by myeloid CD11b(+) DC. Moreover, we demonstrate that triggering NK cell activation by monoclonal antibodies (mAbs)-coated tumor cells leads to efficient DC cross-presentation, supporting the concept that NK cells can contribute to therapeutic mAbs efficiency by inducing downstream adaptive immunity. Taken together, our findings point toward a novel role of human NK cells bridging innate and adaptive immunity through selective induction of cell-associated Ag cross-presentation by CD141(high) DC, a process that could be exploited to better harness Ag-specific cellular immunity in immunotherapy.

Aberrant drainage of the umbilical vein into the coronary sinus without ductus venosus agenesis

We describe a case series of 4 fetuses with ectopic connections of the ductus venosus to the coronary sinus detected prospectively between August 2011 and February 2012 in 2 congenital cardiologic centers. An enlarged coronary sinus alerted the sonographer. Fetal echocardiography showed ectopic connection of the ductus venosus in an enlarged coronary sinus in all 4 cases. To our knowledge, this anatomic form of ectopic umbilical vein drainage has not previously been reported. The infants were doing well. This venous variant should be considered in cases of isolated coronary sinus dilatation after elimination of a left superior vena cava and a totally anomalous pulmonary vein connection.

Tumor promotion by intratumoral plasmacytoid dendritic cells is reversed by TLR7 ligand treatment

Plasmacytoid dendritic cells (pDC) are key regulators of antiviral immunity. In previous studies, we reported that pDC-infiltrating human primary breast tumors represent an independent prognostic factor associated with poor outcome. To understand this negative impact of tumor-associated pDC (TApDC), we developed an orthotopic murine mammary tumor model that closely mimics the human pathology, including pDC and regulatory T cell (Treg) infiltration. We showed that TApDC are mostly immature and maintain their ability to internalize antigens in vivo and to activate CD4(+) T cells. Most importantly, TApDC were specifically altered for cytokine production in response to Toll-like receptor (TLR)-9 ligands in vitro while preserving unaltered response to TLR7 ligands (TLR7L). In vivo pDC depletion delayed tumor growth, showing that TApDC provide an immune-subversive environment, most likely through Treg activation, thus favoring tumor progression. However, in vivo intratumoral administration of TLR7L led to TApDC activation and displayed a potent curative effect. Depletion of pDC and type I IFN neutralization prevented TLR7L antitumoral effect. Our results establish a direct contribution of TApDC to primary breast tumor progression and rationalize the application of TLR7 ligands to restore TApDC activation in breast cancer. Cancer Res; 73(15); 4629-40. ©2013 AACR.

Ebstein's anomaly and tricuspid valve dysplasia: prognosis after diagnosis in utero

Tricuspid valve malformation is a rare congenital heart disease. Prenatal diagnosis of Ebstein's anomaly (EA) and tricuspid valve dysplasia (TVD) is associated with high mortality. There are conflicting reports concerning accurate prognostication after diagnosis in utero. The aim of our study was to assess prognostic factors based on our experience. We reviewed 37 fetuses between 1984 and June 2010 comprising 26 cases of EA and 11 cases of TVD. There were 10 terminations, 5 intrauterine deaths, 8 neonatal deaths, and 14 survivors. We found that the major prognostic factor for outcome was the flow pattern through the pulmonary valve on the first echocardiogram. Retrograde flow was strongly correlated with fetal or neonatal death (p = 8 × 10(-5)), and anterograde flow predicted good outcome (p = 8 × 10(-5)). In contrast, cardiothoracic indexes, right to left-ventricular ratio, and Celermajer index were not useful prognostic markers. The Simpson Andrews Sharland score, which was more complex, was well correlated with our series. Flow through the pulmonary valve on the first echocardiogram is a simple and excellent prognostic factor when major tricuspid valve disease is diagnosed in utero. Fetuses should be monitored throughout pregnancy, particularly those with retrograde ductus arteriosus, because several hemodynamic factors may worsen the prognosis.

Impaired IFN-α production by plasmacytoid dendritic cells favors regulatory T-cell expansion that may contribute to breast cancer progression

Infiltration and dysfunction of immune cells have been documented in many types of cancers. We previously reported that plasmacytoid dendritic cells (pDC) within primary breast tumors correlate with an unfavorable prognosis for patients. The role of pDC in cancer remains unclear but they have been shown to mediate immune tolerance in other pathophysiologic contexts. We postulated that pDC may interfere with antitumor immune response and favor tolerance in breast cancer. The present study was designed to decipher the mechanistic basis for the deleterious impact of pDC on the clinical outcome. Using fresh human breast tumor biopsies (N = 60 patients), we observed through multiparametric flow cytometry increased tumor-associated (TA) pDC (TApDC) rates in aggressive breast tumors, i.e., those with high mitotic index and the so-called triple-negative breast tumors (TNBT). Furthermore, TApDC expressed a partially activated phenotype and produced very low amounts of IFN-α following toll-like receptor activation in vitro compared with patients' blood pDC. Within breast tumors, TApDC colocalized and strongly correlated with TA regulatory T cells (TATreg), especially in TNBT. Of most importance, the selective suppression of IFN-α production endowed TApDC with the unique capacity to sustain FoxP3(+) Treg expansion, a capacity that was reverted by the addition of exogenous IFN-α. These findings indicate that IFN-α-deficient TApDC accumulating in aggressive tumors are involved in the expansion of TATreg in vivo, contributing to tumor immune tolerance and poor clinical outcome. Thus, targeting pDC to restore their IFN-α production may represent an attractive therapeutic strategy to overcome immune tolerance in breast cancer.

ICOS-ligand expression on plasmacytoid dendritic cells supports breast cancer progression by promoting the accumulation of immunosuppressive CD4+ T cells

Human breast tumors are infiltrated by memory CD4(+) T cells along with increased numbers of regulatory T cells (Treg) and plasmacytoid dendritic cells (pDC) that facilitate immune escape and correlate with poor prognosis. Here, we report that inducible costimulatory molecule (ICOS), a T cell costimulatory molecule of the CTLA4/PD1/CD28 family, is expressed mostly by tumor-associated Treg in primary breast tumors. A large proportion of these ICOS(+) Treg were Ki67(+) and this evident proliferative expansion was found to rely on interactions with tumor-associated pDC. Indeed, tumor-associated Treg highly expanded in presence of pDC but failed to proliferate under CD3/CD28 signal. In vitro experiments revealed that the addition of a neutralizing anti-ICOS antibody blocked pDC-induced Treg expansion and interleukin-10 secretion by memory CD4(+) T cells, establishing a pivotal role for ICOS in this process. Supporting these findings, the presence of ICOS(+) cells in clinical specimens of breast cancer correlated with a poor prognosis. Together, our results highlight an important relationship between Treg and pDC in breast tumors, and show that ICOS/ICOS-L interaction is a central event in immunosuppression of tumor-associated memory CD4(+) T cells. These findings strongly rationalize antibody-mediated ICOS blockade as a powerful clinical strategy to correct immune escape and promote therapeutic responses in breast cancer.

Abstract 5402: Functionally altered plasmacytoid DC in breast tumor environment play a central role in Treg and Tr1-like expansion through ICOS engagement

Tumor immunosubversion occurs through various mechanisms including the selective recruitment of CD4+ regulatory T cell (Treg) and the alteration of dendritic cell (DC) physiology. We reported that the presence of high number of both Treg and/or plasmacytoid DC (pDC) correlates with poor prognosis in breast (1-2) and ovarian carcinoma (3). We previously demonstrated that CCR4+ Treg are recruited from the periphery to the breast tumor through CCL22 production by breast tumor cells under exposure to IFNg, IL-1b and TNFa, consecutively to Macrophages and Natural killer cell detection of transformed cells (4). We report here that Tumor-associated Treg (Ta-Treg) are highly activated (GITRhighHLA-DRhighCD39high) and show a selective expression of high levels of ICOS, proliferate in situ (Ki-67+) but unlike blood Treg, did not proliferate ex vivo under CD3/CD28 co-stimulation in presence of IL-2. On the other hand, Ta-pDC expressed a partially activated phenotype but lacked their principal function, i.e., their type-I interferon production (key mediator of antiviral and tumoral immune responses), is strongly impaired. We show that Ta-Treg and Ta-pDC colocalize within lymphoid structures in vivo and demonstrate the unique capacity of Ta-pDC to favour proliferation of Ta-Treg and CD4+ T cells secreting IL-10. Of importance, this Treg amplification is strongly reduced by addition of exogenous IFNa. Furthermore, targeting ICOS with a neutralizing antibody suppresses Ta-Treg proliferation as well as IL-10 secretion in pDC/CD4+ T cell co-culture, demonstrating a role of ICOS-ICOS-L interaction in Ta-Treg proliferation mediated by Ta-pDC. In contrast, blocking ICOS does not impact T cell responses induced by mDC that, contrary to pDC, do not support Treg enrichment or high IL-10 secretion. Altogether these observations suggest that ICOS represents a therapeutic target in breast cancer that may allow to restore anti-tumor immunity. Grant supports: BCRF, Ligue nationale contre le cancer, ARC, Comité départementaux de la Ligue contre le cancer, INCa. 1. Treilleux I, Blay JY, Bendriss-Vermare N, et al. Dendritic cell infiltration and prognosis of early stage breast cancer. Clin Cancer Res. 2004; 10:7466-74. 2. Gobert M.., Caux C., Blay JY. and Ménétrier-Caux C. Treg recruited through CCL22/CCR4 are selectively activated in lymphoid infiltrates surrounding primary breast tumors and lead to an adverse clinical outcome. Cancer Research 2009; 69:2000-9. 3. Labidi-Galy SI, Ray-Coquard I, Ménétrier-Caux C, Caux C, Blay JY and Bendriss-Vermare N. Systemic and local dysfunctions of pDC in ovarian carcinoma could contribute to immune tolerance. Cancer Res. 2011; 71:5423-34 4. Faget J., Blay J.Y., Caux C. and Ménétrier-Caux C. Early detection of tumor cells by innate immune cells leads to Treg recruitment through CCL22 production by tumor cells. Cancer Res. 2011; 71:6143-52

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5402. doi:1538-7445.AM2012-5402

Early detection of tumor cells by innate immune cells leads to T(reg) recruitment through CCL22 production by tumor cells

In breast carcinomas, patient survival seems to be negatively affected by the recruitment of regulatory T cells (T(reg)) within lymphoid aggregates by CCL22. However, the mechanisms underpinning this process, which may be of broader significance in solid tumors, have yet to be described. In this study, we determined how CCL22 production is controlled in tumor cells. In human breast carcinoma cell lines, CCL22 was secreted at low basal levels that were strongly increased in response to inflammatory signals [TNF-α, IFN-γ, and interleukin (IL)-1β], contrasting with CCL17. Primary breast tumors and CD45(+) infiltrating immune cells appeared to cooperate in driving CCL22 secretion, as shown clearly in cocultures of breast tumor cell lines and peripheral blood mononuclear cells (PBMC) or their supernatants. We determined that monocyte-derived IL-1β and TNF-α are key players as monocyte depletion or neutralization of these cytokines attenuated secretion of CCL22. However, when purified monocytes were used, exogenous human IFN-γ was also required to generate this response suggesting a role for IFN-γ-producing cells within PBMCs. In this setting, we found that human IFN-γ could be replaced by the addition of (i) IL-2 or K562-activated natural killer (NK) cells or (ii) resting NK cells in the presence of anti-MHC class I antibody. Taken together, our results show a dialogue between NK and tumor cells leading to IFN-γ secretion, which in turn associates with monocyte-derived IL-1β and TNF-α to drive production of CCL22 by tumor cells and subsequent recruitment of T(reg). As one validation of this conclusion in primary breast tumors, we showed that NK cells and macrophages tend to colocalize within tumors. In summary, our findings suggest that at early times during tumorigenesis, the detection of tumor cells by innate effectors (monocytes and NK cells) imposes a selection for CCL22 secretion that recruits T(reg) to evade this early antitumor immune response.

Quantitative and functional alterations of plasmacytoid dendritic cells contribute to immune tolerance in ovarian cancer

In ovarian cancer, the immune system fails to eradicate established tumors partly due to the induction of immune tolerance within tumor microenvironment. In this study, we investigated the contribution of plasmacytoid dendritic cells (pDC) in the establishment of immune tolerance in a cohort of 44 ovarian cancer patients. In the tumor and malignant ascites, CD4(+)CD123(+)BDCA2(+) pDC were the most abundant dendritic cell subset; however, they were profoundly depleted in peripheral blood. The presence of pDC in primary ovarian cancer, but not ascites, was an independent prognostic factor associated with early relapse. Following chemotherapy, we observed a partial restoration of blood pDC levels in patients in complete remission. These findings show preferential recruitment of pDC into tumors where they express a partially mature phenotype that may reflect an in situ activation. Importantly, compared with pDC found in ascites or blood, tumor-associated pDC (TApDC) produced less IFN-α, TNF-α, IL-6, macrophage inflammatory protein-1β, and RANTES in response to toll-like receptor stimulation, and alterations in pDC functions were mainly mediated through tumor-derived TNF-α and TGF-β. Unlike ascites-derived pDC, TApDC induced IL-10 production from allogeneic naive CD4(+) T lymphocytes, suggesting the existence of a paracrine immunosuppressive loop. Taken together, our findings indicate that both local and systemic dysfunction of pDC play a critical role in the progression of ovarian cancer via induction of immune tolerance.

Abstract 472: In vivo activation of plasmacytoid dendritic cells using TLR7-L induced an efficient antitumoral effect in a murine mammary preclinical tumor model

Dendritic cells (DC) are professional antigen presenting cells involved in both the induction and the polarization of adaptive immune response. Among them figure conventional myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC), the last ones being involved in the induction of antiviral immune response through type I interferons production. In human breast cancer, we have previously shown that pDC infiltration is an independent factor correlated with a poor prognosis. Although pDC can induce efficient T cell responses against viral or endogenous antigens, it remains unclear whether pDC are efficient for cross presentation of tumor antigens acquired from dying tumor cells. Moreover, pDC have been described in some contexts to be involved in the induction of immune tolerance by promoting regulatory T cell (Treg) differentiation. Thus herein we evaluate their ability to induce efficient antitumoral response after activation by viral signals such as TLR7L or TLR9L.

First, we developed several preclinical murine mammary tumor models derived from spontaneous mammary tumors arose in transgenic mice MMTV-Her2/neu expressing the rat proto-oncogene neu under the control of MMTV promoter. Several tumor cell lines (NEU) expressing HER2/Neu were derived from these spontaneous mammary tumors and were implanted in the 4th fad pad of immunotolerant transgenic mice MMTV-Her2/neu or in immunocompetent FVB wild type mice witch developed an antibody immune response against the rat Her2/neu proto-oncogene. All NEU cell lines were highly tumorigeneic in immunotolerant mice but interestingly when implanted in FVBwt mice some were rejected, some escape by immunoediting with a selection of a NEU negative variant and one (NEU15) escape by another mechanism showing as in human breast cancer the maintenance of Her2/Neu expression despite an anti-tumoral immune response. We showed that NEU15 tumors in FVBwt mice (NEU15wt) were significantly more infiltrated by pDC and Treg than NEU15 tumors in immunotolerant transgenic mice (NEU15Tg). Secondly, we focused on this NEU15wt preclinical model and analyzed the functional status of tumor associated pDC (TApDC) and TAmDC. We showed that TApDC are altered for their capacity to secrete type I IFN in response to TLR9 engagement while preserving their ability to respond to viral signals such as Influenza and TLR7 ligands. TAmDC undergo a spontaneous maturation in culture independently of TLR engagement and secrete inflammatory cytokines (TNFα, RANTES) but also IL-10 and no IL12. In vivo immuno intervention using intra-tumoral injection of TLR-7L (50μg D13 and D20) in pre-established NEU15wt tumors allowed 50% of complete tumor rejection. IFNα production was detected in mice sera 3 hours after TLR-7L intratumoral injection. The impact of in vivo depletion of pDC on the therapeutic efficiency of TLR7L is under investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 472. doi:10.1158/1538-7445.AM2011-472

TLR3 and Rig-like receptor on myeloid dendritic cells and Rig-like receptor on human NK cells are both mandatory for production of IFN-gamma in response to double-stranded RNA

Cross-talk between NK cells and dendritic cells (DCs) is critical for the potent therapeutic response to dsRNA, but the receptors involved remained controversial. We show in this paper that two dsRNAs, polyadenylic-polyuridylic acid and polyinosinic-polycytidylic acid [poly(I:C)], similarly engaged human TLR3, whereas only poly(I:C) triggered human RIG-I and MDA5. Both dsRNA enhanced NK cell activation within PBMCs but only poly(I:C) induced IFN-gamma. Although myeloid DCs (mDCs) were required for NK cell activation, induction of cytolytic potential and IFN-gamma production did not require contact with mDCs but was dependent on type I IFN and IL-12, respectively. Poly(I:C) but not polyadenylic-polyuridylic acid synergized with mDC-derived IL-12 for IFN-gamma production by acting directly on NK cells. Finally, the requirement of both TLR3 and Rig-like receptor (RLR) on mDCs and RLRs but not TLR3 on NK cells for IFN-gamma production was demonstrated using TLR3- and Cardif-deficient mice and human RIG-I-specific activator. Thus, we report the requirement of cotriggering TLR3 and RLR on mDCs and RLRs on NK cells for a pathogen product to induce potent innate cell activation.

Regulatory T cells recruited through CCL22/CCR4 are selectively activated in lymphoid infiltrates surrounding primary breast tumors and lead to an adverse clinical outcome

Immunohistochemical analysis of FOXP3 in primary breast tumors showed that a high number of tumor-infiltrating regulatory T cells (Ti-Treg) within lymphoid infiltrates surrounding the tumor was predictive of relapse and death, in contrast to those present within the tumor bed. Ex vivo analysis showed that these tumor-infiltrating FOXP3(+) T cells are typical Treg based on their CD4(+)CD25(high)CD127(low)FOXP3(+) phenotype, their anergic state on in vitro stimulation, and their suppressive functions. These Ti-Treg could be selectively recruited through CCR4 as illustrated by (a) selective blood Treg CCR4 expression and migration to CCR4 ligands, (b) CCR4 down-regulation on Ti-Treg, and (c) correlation between Ti-Treg in lymphoid infiltrates and intratumoral CCL22 expression. Importantly, in contrast to other T cells, Ti-Treg are selectively activated locally and proliferate in situ, showing T-cell receptor engagement and suggesting specific recognition of tumor-associated antigens (TAA). Immunohistochemical stainings for ICOS, Ki67, and DC-LAMP show that Ti-Treg were close to mature DC-LAMP(+) dendritic cells (DC) in lymphoid infiltrates but not in tumor bed and were activated and proliferating. Furthermore, proximity between Ti-Treg, CD3(+), and CD8(+) T cells was documented within lymphoid infiltrates. Altogether, these results show that Treg are selectively recruited within lymphoid infiltrates and activated by mature DC likely through TAA presentation, resulting in the prevention of effector T-cell activation, immune escape, and ultimately tumor progression. This study sheds new light on Treg physiology and validates CCR4/CCL22 and ICOS as therapeutic targets in breast tumors, which represent a major health problem.

Effect of natural iron fertilization on carbon sequestration in the Southern Ocean

The availability of iron limits primary productivity and the associated uptake of carbon over large areas of the ocean. Iron thus plays an important role in the carbon cycle, and changes in its supply to the surface ocean may have had a significant effect on atmospheric carbon dioxide concentrations over glacial-interglacial cycles. To date, the role of iron in carbon cycling has largely been assessed using short-term iron-addition experiments. It is difficult, however, to reliably assess the magnitude of carbon export to the ocean interior using such methods, and the short observational periods preclude extrapolation of the results to longer timescales. Here we report observations of a phytoplankton bloom induced by natural iron fertilization--an approach that offers the opportunity to overcome some of the limitations of short-term experiments. We found that a large phytoplankton bloom over the Kerguelen plateau in the Southern Ocean was sustained by the supply of iron and major nutrients to surface waters from iron-rich deep water below. The efficiency of fertilization, defined as the ratio of the carbon export to the amount of iron supplied, was at least ten times higher than previous estimates from short-term blooms induced by iron-addition experiments. This result sheds new light on the effect of long-term fertilization by iron and macronutrients on carbon sequestration, suggesting that changes in iron supply from below--as invoked in some palaeoclimatic and future climate change scenarios--may have a more significant effect on atmospheric carbon dioxide concentrations than previously thought.

Molecular characterization of Clostridium difficile clinical isolates in a geriatric hospital

The discriminatory potential of a combination of various typing methods was evaluated on a set of 21 Clostridium difficile isolates obtained from symptomatic patients hospitalized in a geriatric unit and 7 non-toxigenic isolates from the same hospital. Isolates were firstly serotyped and toxinotyped. Of the 28 isolates, 19 belonged to serogroup A. PCR-ribotyping and PCR-RFLP on the fliC and slpA genes were then applied to these 19 isolates. The results suggest that the combination of PCR-ribotyping with PCR-RFLP analysis of slpA could be more discriminatory and suitable for studying C. difficile epidemiology.

Human CD4+CD25high regulatory T cells modulate myeloid but not plasmacytoid dendritic cells activation

Human CD4(+)CD25(+) regulatory T cells (Treg) play an essential role in the prevention of autoimmune diseases. However, the mechanisms of immune suppression and the spectrum of cells they target in vivo remain incompletely defined. In particular, although Treg directly suppress conventional T cells in vitro, they have been shown to inhibit the Ag-presenting functions of macrophage- and monocyte-derived dendritic cells (DC). We have now studied the maturation of human blood-derived myeloid DC and plasmacytoid DC activated with TLR ligands in the presence of Treg. Preactivated Treg suppressed strongly TLR-triggered myeloid DC maturation, as judged by the blocking of costimulatory molecule up-regulation and the inhibition of proinflammatory cytokines secretion that resulted in poor Ag presentation capacity. Although IL-10 played a prominent role in inhibiting cytokines secretion, suppression of phenotypic maturation required cell-cell contact and was independent of TGF-beta and CTLA-4. In contrast, the acquisition of maturation markers and production of cytokines by plasmacytoid DC triggered with TLR ligands were insensitive to regulatory T cells. Therefore, human Treg may enlist myeloid, but not plasmacytoid DC for the initiation and the amplification of tolerance in vivo by restraining their maturation after TLR stimulation.

Methylglyoxal impairs the insulin signaling pathways independently of the formation of intracellular reactive oxygen species

Nonenzymatic glycation is increased in diabetes and leads to elevated levels of advanced glycation end products (AGEs), which link hyperglycemia to the induction of insulin resistance. In hyperglycemic conditions, intracellularly formed alpha-ketoaldehydes, such as methylglyoxal, are an essential source of intracellular AGEs, and the abnormal accumulation of methylglyoxal is related to the development of diabetes complications in various tissues and organs. We have previously shown in skeletal muscle that AGEs induce insulin resistance at the level of metabolic responses. Therefore, it was important to extend our work to intermediates of the biosynthetic pathway leading to AGEs. Hence, we asked the question whether the reactive alpha-ketoaldehyde methylglyoxal has deleterious effects on insulin action similar to AGEs. We analyzed the impact of methylglyoxal on insulin-induced signaling in L6 muscle cells. We demonstrate that a short exposure to methylglyoxal induces an inhibition of insulin-stimulated phosphorylation of protein kinase B and extracellular-regulated kinase 1/2, without affecting insulin receptor tyrosine phosphorylation. Importantly, these deleterious effects of methylglyoxal are independent of reactive oxygen species produced by methylglyoxal but appear to be the direct consequence of an impairment of insulin-induced insulin receptor substrate-1 tyrosine phosphorylation subsequent to the binding of methylglyoxal to these proteins. Our data suggest that an increase in intracellular methylglyoxal content hampers a key molecule, thereby leading to inhibition of insulin-induced signaling. By such a mechanism, methylglyoxal may not only induce the debilitating complications of diabetes but may also contribute to the pathophysiology of diabetes in general.

[ENVOL study on the medical management of varicella and its complications in French ambulatory care]

OBJECTIVE

The authors had for aim to describe the management of varicella and its complications in French ambulatory care.

METHODS

A descriptive prospective national survey was carried out in France on patients visiting a random sample of French GPs and pediatricians (investigators) having diagnosed varicella. During an inclusion period of 4 months, the investigators enrolled all patients (adults-children) who presented with varicella or varicella related complications, and who had not previously visited the investigator for this episode. Three questionnaires were used to record the data.

RESULTS

One thousand two hundred patients were enrolled by 393 physicians 75% of whom were GPs. Ninety-four percent of patients were children under 13 years of age (group I). The sex ratio (M/F) was 1.1. The mean age was 3.5 years in group I and 23.8 years in patients over 13 years of age (group II). The mean length of the varicella episode was about 10.7 days. Most patients were given a pharmaceutical prescription on inclusion, 1% were also prescribed medical procedures, 0.3% were given local treatment, and 0.09% underwent physical therapy sessions. A proportion of 12.6% of patients visited their physician twice or more for the same episode. Six group I children were hospitalized. Eighty-seven patients presented with at least one complication i.e. 7.8% (95%CI=6.3-9.3) of all episodes, mainly bacterial superinfections.

CONCLUSIONS

The rate of complications associated with varicella infection was higher than usually reported in France but in the same order of magnitude as in other developed countries. Bacterial superinfections were found to be the most frequent complications of varicella.

Seroprevalence of varicella in the French population

OBJECTIVES

To assess the age-specific seroprevalence of varicella in the French population and to explore age-adjusted differences according to gender and geographic region.

METHODS

Data were obtained from 1257 randomly selected, frozen serum samples, from subjects 1-30 years of age, that were sent to the Pasteur-Cerba laboratory in November 2003 to January 2004 for the following clinical indications: allergies, respiratory infections, herpes virus infections excluding varicella and endocrinologic tests. IgG concentrations were tested with an indirect enzyme immunoassay. Statistical analyses included use of locally weighted, scatterplot smoothers.

RESULTS

Age-specific seroprevalence of varicella increased by >6-fold between 1 and 8 years of age, ie, from 15.0% (95% confidence interval, 8.6-23.5%) for subjects 1-2 years of age to 89.0% (95% confidence interval, 81.0-94.3%) for those 7-8 years of age. The smoothed curve of age-specific seroprevalence suggested that the steepest rate of increase occurred between 1 and 8 years of age, followed by a considerable slowing in the rate of increase, reaching a prevalence of approximately 95% by age 30. Varicella seroprevalence rates were similar for the samples referred for the 4 clinical indications, as follows: allergies, 76.2%; respiratory infections, 74.0%; herpes virus infections excluding varicella, 73.3%; endocrinologic tests, 73.7% (P = 0.84).

CONCLUSIONS

Most varicella-zoster virus infections occur during early childhood. Seroprevalence rates reach approximately 50% by 4 years of age and approximately 90% by 8 years. Therefore, the best strategy to reduce the prevalence of wild-type varicella-zoster virus in the French population would be to immunize children 12-18 months of age, as is currently performed in the United States.

Risk of malaria among French adult travellers

BACKGROUND

Imported malaria remains an important, but often unrecognised, health problem in Europe. Little information exists on the incidence of imported malaria with respect to exposure. This study aimed to estimate the incidence of malaria in a cohort of travellers with respect to protection measures.

METHOD

In all 13,017 participants enrolled in a French general population cohort (SU.VI.MAX cohort) and followed-up over 8 years were investigated. All participants received a retrospective questionnaire about travel to malaria-endemic countries relating to countries visited, duration of stay, use of protection measures and chemoprophylaxis. Malaria cases was confirmed from medical records.

RESULTS

Data were obtained for 752 individuals who made 1,393 trips to malaria-endemic areas. This sample was predominantly middle-class and high-risk groups such as migrants were not represented. Mechanical protection was used in 589 trips (42.3%) and chemoprophylaxis in 1,017 trips (73.0%). This was appropriate for the zone in 615 trips (44.0%) and adequate compliance was reported in the case of 497 trips (35.6%). Appropriate chemoprophylaxis and physical protection measures were used in 21.7% of the trips. Six laboratory-confirmed cases of imported malaria yielded an estimated incidence density of 148 cases/month of exposure/10,000 travellers. In five cases, appropriate protection measures had not been taken.

CONCLUSION

Appropriate chemoprophylaxis and physical protection measures against malaria infection are used by less than one-quarter of a sample of predominantly middle-class travellers from France to endemic areas. More intense education measures need to be implemented to reduce the risk of imported malaria.

Virus overrides the propensity of human CD40L-activated plasmacytoid dendritic cells to produce Th2 mediators through synergistic induction of IFN-{gamma} and Th1 chemokine production

Depending on the activation status, plasmacytoid dendritic cells (PDC) and myeloid DC have the ability to induce CD4 T cell development toward T helper cell type 1 (Th1) or Th2 pathways. Thus, we tested whether different activation signals could also have an impact on the profile of chemokines produced by human PDC. Signals that induce human PDC to promote a type 1 response (i.e., viruses) and a type 2 response [i.e., CD40 ligand (CD40L)] also induced PDC isolated from tonsils to secrete chemokines preferentially attracting Th1 cells [such as interferon-gamma (IFN-gamma)-inducible protein (IP)-10/CXC chemokine ligand 10 (CXCL10) and macrophage inflammatory protein-1beta/CC chemokine ligand 4 (CCL4)] or Th2 cells (such as thymus and activation-regulated chemokine/CCL17 and monocyte-derived chemokine/CCL22), respectively. Activated natural killer cells were preferentially recruited by supernatants of virus-activated PDC, and supernatants of CD40L-activated PDC attracted memory CD4(+) T cells, particularly the CD4(+)CD45RO(+)CD25(+) T cells described for their regulatory activities. It is striking that CD40L and virus synergized to trigger the production of IFN-gamma by PDC, which induces another Th1-attracting chemokine monokine-induced by IFN-gamma/CXCL9 and cooperates with endogenous type I IFN for IP-10/CXCL10 production. In conclusion, our studies reveal that PDC participate in the selective recruitment of effector cells of innate and adaptive immune responses and that virus converts the CD40L-induced Th2 chemokine patterns of PDC into a potent Th1 mediator profile through an autocrine loop of IFN-gamma.

Economic evaluation of a combined DTPa, hepatitis B, polio, Hib vaccine. Potential impact of the introduction of Infanrix-Hexa in the French childhood immunisation schedule

A new hexavalent combination vaccine, Infanrix-HEXA, including a recombinant hepatitis B vaccine in addition to the vaccines for diphtheria, tetanus, pertussis, poliomyelitis, and Haemophilus influenzae type B, has recently become available in France. The objectives of this study were to: (1) estimate the break-even price of Infanrix-Hexa for the National Sickness Fund; (2) evaluate its potential impact on vaccine coverage for hepatitis B and the corresponding budget impact. The public price of Infanrix-HEXA associated with a break-even point would be 53.77 euro. Our analyses suggested that other estimates based on a societal perspective including opportunity and indirect costs remained close to this value. The annual additional reimbursed cost of protecting an infant against the risk of hepatitis B would be 28.20 euro per child, or about 21 million euro for an annual cohort of 760,000 births (total cost, 35 million euro). The number of infants protected against hepatitis B could increase from 230,000 in the current situation to about 600,000.

OSCAR is an FcRgamma-associated receptor that is expressed by myeloid cells and is involved in antigen presentation and activation of human dendritic cells

We have isolated a novel cell surface molecule, the human homolog of osteoclast-associated receptor (OSCAR). Unlike mouse OSCAR, hOSCAR is widely transcribed in cells of the myeloid lineage. Notably, hOSCAR is expressed on circulating blood monocytes and CD11c(+) dendritic cells but not on T and B cells. hOSCAR is continually expressed during differentiation of CD14(+) monocytes into dendritic cells and maintained after maturation. hOSCAR associates with the FcRgamma as shown by translocation of FcRgamma to the cell surface in presence of hOSCAR and coimmunoprecipitation from transfected cell lines and ex vivo cells. Engagement of hOSCAR with specific mAb leads to Ca(2+) mobilization and cytokine release, indicators of cellular activation. Endocytosis of the receptor in dendritic cells was observed, followed by passage of the internalized material into Lamp-1(+) and HLA-DR(+) compartments, suggesting a role in antigen uptake and presentation. Dendritic cells were able to stimulate a T-cell clone specific for an epitope of mouse IgG1 after uptake and processing of the hOSCAR-specific antibody, demonstrating the capacity of this receptor to mediate antigen presentation. hOSCAR thus represents a novel class of molecule expressed by dendritic cells involved in the initiation of the immune response.

Estimating the Cost-Effectiveness of Stroke Units in France Compared With Conventional Care

Background and Purpose— The incidence of stroke in France is estimated at between 120 000 and 150 000 cases per year. This modeling study assessed the clinical and economic benefits of establishing specialized stroke units compared with conventional care.

Methods— Data from the Dijon stroke registry were used to determine healthcare trajectories according to the degree of autonomy and organization of patient care. The relative risks of death or institutionalization or death or dependence after passage through a stroke unit were compared with conventional care. These risks were then inserted with the costing data into a Markov model to estimate the cost-effectiveness of stroke units.

Results— Patients cared for in a stroke unit survive more trimesters without sequelae in the 5 years after hospitalization than those cared for conventionally (11.6 versus 8.28 trimesters). The mean cost per patient at 5 years was estimated at 30 983 for conventional care and 34 638 in a stroke unit. An incremental cost-effectiveness ratio for stroke units of 1359 per year of life gained without disability was estimated.

Conclusions— The cost-effectiveness ratio for stroke units is much lower than the threshold (53 400 ) of acceptability recognized by the international scientific community. This finding justifies organizational changes in the management of stroke patients and the establishment of stroke units in France.

Cost-effectiveness of hepatitis A vaccine in prevention of secondary hepatitis A infection

Using a decision-tree based model, we investigated the cost-effectiveness of several vaccination strategies for household, day care center and nursery/primary school contacts of primary cases of hepatitis A in France. Depending on the age groups vaccinated, the cost per symptomatic case avoided varied between 700 and 1,300 Euro (1 Euro = 0.93 US dollars) for household contacts. Vaccination of contacts in day care centers and schools resulted in cost-savings. However, these findings are contingent on the limited and controversial data available on vaccine protective efficacy. In particular, the question of the relative efficacy of vaccination as compared with the use of immunoglobulins needs further study.

[Cost of colorectal cancer in France in 1999]

AIM

Due to high incidence and disease severity, colorectal cancer is a major public health concern in western countries. Few studies have been devoted to estimating its cost in France. The aim of this study was to analyze the direct (medical) and indirect (short-term disability, long-term disability, premature death) costs of colorectal cancer in France.

METHODS

This cost-of-illness study was based on data available for 1999. Two evaluation perspectives were considered: French social security system (medical care + daily allowances + disability allowances) and the society (medical care + production losses). Sources of data used in this analysis were: PMSI (hospital care), EPPM-IMS study (ambulatory care) and the GAZEL cohort (short-term disability).

RESULTS

Direct costs of colorectal cancer in France amounted in 1999 to more than 469.7 million euros, of which 98% were induced by hospitalisation (on an outpatient or an inpatient basis). Indirect costs represented in 1999 for the French social security system an amount of 85.9 million, of which 71% were due to disability allowances. Taking into account the society's point of view, indirect costs corresponded to production losses of 528.1 million. Total costs of colorectal cancer amounted 555.5 million for the social security system and 997 million for the society.

CONCLUSION

These results confirm the high economic burden of colorectal cancer for the French social security system and for the society in general.

Dilated coronary sinus in prenatal echocardiography; identification, associations and outcome

The dilated coronary sinus (DCS) has only recently been clearly visualised in the fetus due to progress in prenatal echography. This is a retrospective study of 22 fetuses presenting with DCS revealed by prenatal echography. We report the circumstances leading to the detection of a DCS and the neonatal outcome of these fetuses. The coronary sinus was defined as dilated depending on its visualisation in cross-section from the '4 chamber' view, as well as a pseudo inter-atrial septal defect from a more posterior view. In each case the gestational age, circumstances of detection, associated anomalies and postnatal outcome are reported. The circumstances were: evaluation of a clearly identified DCS in four cases and during detailed fetal echocardiography because of suspected congenital heart disease in 18 cases. Five cases were associated with a cardiac anomaly, three with an extracardiac anomaly, six with both cardiac and extracardiac anomaly and eight were isolated. Postnatal outcome was related to the associated anomaly. In conclusion, it is important that the echography image be correctly interpreted, as a DCS often implies possible associated defects and therefore affects prognosis. When not associated with other anomalies this condition is not considered serious.

Sequential involvement of CCR2 and CCR6 ligands for immature dendritic cell recruitment: possible role at inflamed epithelial surfaces

To reach the site of antigen deposition at epithelial surfaces, dendritic cells (DC) have to traverse the endothelial barrier, progress through the tissue (i.e., dermis) and cross the dermo-epithelial junction (basal membrane). In the present study, we demonstrate that (1) circulating blood DC and monocytes express high levels of CCR2 and primarily respond to monocyte chemotactic protein (MCP) and not to macrophage inflammatory protein (MIP)-3alpha/CCL20; (2) while the CD34(+) hematopoietic progenitor cells (HPC)-derived CD1a(+) precursors committed to Langerhans cell differentiation primarily respond to MIP-3alpha/CCL20, the HPC-derived CD14(+) precursors respond to both MCP and MIP-3alpha/CCL20; (3) in concordance with the sequential expression of CCR2 and CCR6, the HPC-derived CD14(+) precursors initially acquire the ability to migrate in response to MCP-4/CCL13 and subsequently in response to MIP-3alpha/CCL20; and (4) in vivo, in inflamed epithelium, MCP-4/CCL13 and MIP-3alpha/CCL20 form complementary gradients, with MCP-4/CCL13 expressed in basal epithelial cells at the contact of blood vessels, while MIP-3alpha/CCL20 expression is restricted to epithelial cells bordering the external milieu. These observations suggest that the recruitment of DC to the site of infection is controlled by the sequential action of different chemokines: (i) CCR2(+) circulating DC or DC precursors are mobilized into the tissue via the expression of MCP by cells lining blood vessels, and (ii) these cells traffic from the tissue to the site of pathogen invasion via the production of MIP-3alpha/CL20 by epithelial cells and the up-regulation of CCR6 in response to the tissue environment.

Mouse type I IFN-producing cells are immature APCs with plasmacytoid morphology

We show here that mouse interferon-alpha (IFN-alpha)-producing cells (mIPCs) are a unique subset of immature antigen-presenting cells (APCs) that secrete IFN-alpha upon stimulation with viruses. mIPCs have a plasmacytoid morphology, can be stained with an antibody to Ly6G and Ly6C (anti-Ly6G/C) and are Ly6C+B220+CD11cloCD4+; unlike other dendritic cell subsets, however, they do not express CD8alpha or CD11b. Although mIPCs undergo apoptosis in vitro, stimulation with viruses, IFN-alpha or CpG oligonucleotides enhanced their survival and T cell stimulatory activity. In vivo, mIPCs were the main producers of IFN-alpha in cytomegalovirus-infected mice, as depletion of Ly6G+/C+ cells abrogated IFN-alpha production. mIPCs produced interleukin 12 (IL-12) in response to viruses and CpG oligodeoxynucleotides, but not bacterial products. Although different pathogens can selectively engage various APC subsets for IL-12 production, IFN-alpha production is restricted to mIPCs' response to viral infection.

Initial amplification of duck hepatitis B virus covalently closed circular DNA after in vitro infection of embryonic duck hepatocytes is increased by cell cycle progression

The relationship between the cell cycle and early amplification of duck hepatitis B virus covalently closed circular (CCC) DNA was studied after in vitro infection of fetal hepatocytes. We first showed that embryonic hepatocytes proliferated for at least 6 days after plating and that complete viral replication including CCC DNA amplification occurred in these proliferating cells. Addition of sodium butyrate or aphidicolin reversibly blocked cells in the G1 phase and diminished CCC DNA synthesis, which was restored after drug withdrawal, concomitantly with the entry of cells into S phase. Cell cycle progression of fetal hepatocytes can be triggered by stimulation with epidermal growth factor (EGF), hepatocyte growth factor (HGF), and tumor growth factor alpha (TGF-alpha). CCC DNA synthesis increased with progression to the S phase induced by EGF, HGF, and TGF-alpha alone or in combination. By contrast, tumor growth factor beta (TGF-beta) alone or in combination with EGF inhibited cell proliferation and viral DNA synthesis. By double labeling, viral nucleocapsids were found predominantly in bromodeoxyuridine-positive hepatocytes, indicating that high viral replication occurs preferentially in proliferating hepatocytes. CCC DNA was also detected mainly in cells in the S and G2/M phases separated from cells in the G1 phase by cell sorting. Taken together, these results show that hepatocyte proliferation may positively regulate the initial amplification of CCC DNA of avian hepadnaviruses, and may explain why mitosis is not necessarily associated with loss of CCC DNA.