109 Game Changing Magnetic Experience in Rural and Urban Wirral Peninsula - Our Experience with Magseed Localisation of Impalpable Breast Tumours and Axillary Nodes

Introduction

Magseed is a novel localization technology in which a tiny seed is inserted to accurately mark the site of breast tumour. These can be detected intra-operatively by sentimag localization system. It aids localization of impalpable breast lesions improving margin clearance rates.

Method

A prospective study of first fifty Magseed localised breast tumour and axillary node excisions in Clatterbridge General Hospital.

Results

A total of 50 patients had 52 Magseed inserted. n = 14 was symptomatic, n = 35 was screen detected and n = 1 was an incidental finding on surveillance mammogram for a B3 lesion. 30 seeds were inserted on the right and 22 were inserted on the left (two were bilateral). 44 seeds were inserted under ultrasound guidance and the rest were targeted under stereo guidance (n = 8). Deployment of two resulted in malposition requiring wire localization. Mean age of subjects was 59.76 (range 31-81) years. Mean time to surgery after magseed insertion was 8.04 (range 1-27) days. Mean weight of the specimen was 48.57(range 10-264) gm. Mean size of the lesions was 20.32 (range 8-65) mm. Redo surgery for margin clearance was performed bringing the re-excision rate to 15.38% (n = 8).

Conclusions

We conclude that Magseed localization of breast tumours is a safe and reliable technique

Abstract P132: Differential and Sex Dependent Expression of Vasopressin Receptors by B Cells, NK Cells, and Dendritic Cells

Arginine vasopressin (AVP) has been shown to play a role in preeclampsia, a hypertensive and immune-mediated disorder in pregnancy. Chronic infusion of AVP during gestation into wild-type mice results in the pregnancy-specific physiological changes (hypertension, kidney damage, fetal growth restriction) as well as increased CD4+ T H 1 and T H 17 associated cytokine responses observed in human pregnancies affected by preeclampsia. Further, human CD4+ T cells isolated from preeclamptic women were found to differentially express AVP receptors (AVPRs) 1a and 2 compared to control pregnancies. Abnormalities in other immune cells are seen during preeclampsia, including auto-antibody production (B cells), poor placental development (natural killer (NK) cells), and increased pro-inflammatory T cells responses (via dendritic cells (DC)). We, therefore, hypothesize that B cells, NK cells, and DC express AVPRs. To begin to understand 1) the expression pattern of AVPRs on CD4- lymphocytes and 2) if there are differences in expression between males and females, we evaluated the expression of AVPR 1a, 2, and 1b specifically on B cells, NK cells, and DC. Each subset was purified via negative selection from de-identified human peripheral blood mononuclear cells obtained through Leukocyte Reduction System (LRS) cone donors at the DeGowin Blood Center followed by qPCR for AVPR 1a, 2, and 1b expression (N=6 per cell type). B cells, NK cells, and DC expressed all three AVPRs 1a, 2, and 1b. All three lymphocyte populations showed a lower expression of AVPR1b compared to expression of 1a and 2, with B cells having the lowest expression of AVPR1b (p<0.05). Interestingly, while B cells and NK cells showed no differences in expression based on sex of the donor, DC isolated from male donors more highly expressed AVPR1b compared to female donors (p=0.0035). In conclusion, we demonstrate that B cells, NK cells, and DC highly express AVPR1a and 2, and that DC expression of AVPRs is sex dependent. Further investigation into the utilization of these receptors by these immune cells and the potential impact of sex-specific differences may elucidate newly identified mechanisms of AVP and immune interactions in not only preeclampsia, but possibly other cardiovascular-related diseases as well.

Interactions between the complement and endothelin systems in normal pregnancy and following placental ischemia

Preeclampsia is characterized by new onset hypertension and fetal growth restriction and is associated with aberrant activation of the innate immune complement system and stressed or ischemic placenta. Previous studies have suggested a role for both endothelin and complement system activation products in new onset hypertension in pregnancy, but inter-relationships of the pathways are unclear. We hypothesized that complement activation following placental ischemia stimulates the endothelin pathway to cause hypertension and impair fetal growth. The Reduced Uterine Perfusion Pressure (RUPP) model results in hypertension and fetal growth restriction in a pregnant rat due to placental ischemia caused by mechanical obstruction of blood flow to uterus and placenta. The effect of inhibitor of complement activation soluble Complement Receptor 1 (sCR1) and endothelin A receptor (ET_A) antagonist atrasentan on hypertension, fetal weight, complement activation (systemic circulating C3a and local C3 placental deposition) and endothelin [circulating endothelin and message for preproendothelin (PPE), ET_A and endothelin B receptor (ET_B) in placenta] in the RUPP rat model were determined. Following placental ischemia, sCR1 attenuated hypertension but increased message for PPE and ET_A in placenta, suggesting complement activation causes hypertension via an endothelin independent pathway. With ET_A antagonism the placental ischemia-induced increase in circulating C3a was unaffected despite inhibition of hypertension, indicating systemic C3a alone is not sufficient. In normal pregnancy, inhibiting complement activation increased plasma endothelin but not placental PPE message. Atrasentan treatment increased fetal weight, circulating endothelin and placental ET_A message, and unexpectedly increased local complement activation in placenta (C3 deposition) but not C3a in circulation, suggesting endothelin controls local placental complement activation in normal pregnancy. Atrasentan also significantly decreased message for endogenous complement regulators Crry and CD55 in placenta and kidney in normal pregnancy. Results of our study indicate that complement/endothelin interactions differ in pregnancies complicated with placental ischemia vs normal pregnancy, as well as locally vs systemically. These data clearly illustrate the complex interplay between complement and endothelin indicating that perturbations of either pathway may affect pregnancy outcomes.

Elevated vasopressin in pregnant mice induces T-helper subset alterations consistent with human preeclampsia

The pathogenesis of preeclampsia (PreE), a hypertensive disorder of pregnancy, involves imbalanced T helper (TH) cell populations and resultant changes in pro- and anti-inflammatory cytokine release. Elevated copeptin (an inert biomarker of arginine vasopressin (AVP)), secretion precedes the development of symptoms in PreE in humans, and infusion of AVP proximal to and throughout gestation is sufficient to initiate cardiovascular and renal phenotypes of PreE in wild-type C57BL/6J mice. We hypothesize that AVP infusion in wild-type mice is sufficient to induce the immune changes observed in human PreE. AVP infusion throughout gestation in mice resulted in increased pro-inflammatory interferon γ (IFNg) (TH1) in the maternal plasma. The TH17-associated cytokine interleukin (IL)-17 was elevated in the maternal plasma, amniotic fluid, and placenta following AVP infusion. Conversely, the TH2-associated anti-inflammatory cytokine IL-4 was decreased in the maternal and fetal kidneys from AVP-infused dams, while IL-10 was decreased in the maternal kidney and all fetal tissues. Collectively, these results demonstrate the sufficiency of AVP to induce the immune changes typical of PreE. We investigated if T cells can respond directly to AVP by evaluating the expression of AVP receptors (AVPRs) on mouse and human CD4+ T cells. Mouse and human T cells expressed AVPR1a, AVPR1b, and AVPR2. The expression of AVPR1a was decreased in CD4+ T cells obtained from PreE-affected women. In total, our data are consistent with a potential initiating role for AVP in the immune dysfunction typical of PreE and identifies putative signaling mechanism(s) for future investigation.