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Dehydrated hereditary stomatocytosis (DHS) (MIM#194380) is a rare autosomal dominant disorder of red blood cell permeability, characterized by a partially or fully compensated nonimmune hemolytic anemia. PIEZO1 is the major gene involved with hundreds of families described, some of which present transient perinatal edema of varying severity. A smaller subset of individuals harbors pathogenic variants in KCNN4, sometimes referred as "Gardos channelopathy." Up to now, only six pathogenic variants in KCNN4 have been reported in 13 unrelated families. Unlike PIEZO1-DHS, neither perinatal edema nor fetal loss has ever been observed linked to KCNN4-DHS. We report the first fetal loss due to non-immune hydrops fetalis related to a pathogenic 28 bp deletion (NM_002250.2: c.1109_1119+17del) in KCNN4. This observation underlies the need for very close monitoring of pregnancies when one parent is affected by DHS regardless of genotype (PIEZO1 or KCNN4).

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BackgroundTo date, the usage of Galaxy, an open-source bioinformatics platform, has been reported primarily in research. We report 5 years’ experience (2015 to 2020) with Galaxy in our hospital, as part of the “Assistance Publique–Hôpitaux de Paris” (AP-HP), to demonstrate its suitability for high-throughput sequencing (HTS) data analysis in a clinical laboratory setting.MethodsOur Galaxy instance has been running since July 2015 and is used daily to study inherited diseases, cancer, and microbiology. For the molecular diagnosis of hereditary diseases, 6970 patients were analyzed with Galaxy (corresponding to a total of 7029 analyses).ResultsUsing Galaxy, the time to process a batch of 23 samples—equivalent to a targeted DNA sequencing MiSeq run—from raw data to an annotated variant call file was generally less than 2 h for panels between 1 and 500 kb. Over 5 years, we only restarted the server twice for hardware maintenance and did not experience any significant troubles, demonstrating the robustness of our Galaxy installation in conjunction with HTCondor as a job scheduler and a PostgreSQL database. The quality of our targeted exome sequencing method was externally evaluated annually by the European Molecular Genetics Quality Network (EMQN). Sensitivity was mean (SD)% 99 (2)% for single nucleotide variants and 93 (9)% for small insertion-deletions.ConclusionOur experience with Galaxy demonstrates it to be a suitable platform for HTS data analysis with vast potential to benefit patient care in a clinical laboratory setting.

Background The SAME device (i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage and wash both red blood cells and platelets. This study evaluated the device performances using human whole blood with the hypothesis that the device will be able to salvage platelets while achieving a erythrocyte yield of 80% and removal ratios of 90% for heparin and 80% for major plasma proteins without inducing signification activation of salvaged cells. Methods Thirty healthy human whole blood units (median volume, 478 ml) were diluted, heparinized, and processed by the device in two consecutive treatment cycles. Samples from the collection reservoir and the concentrated blood were analyzed. Complete blood count was performed to measure blood cell recovery rates. Flow cytometry evaluated the activation state and function of platelets and leukocytes. Heparin and plasma proteins were measured to assess washing performance. Results The global erythrocyte yield was 88.1% (84.1 to 91.1%; median [25th to 75th]) with posttreatment hematocrits of 48.9% (44.8 to 51.4%) and 51.4% (48.4 to 53.2%) for the first and second cycles, respectively. Ektacytometry did not show evidence of erythrocyte alteration. Platelet recovery was 36.8% (26.3 to 43.4%), with posttreatment counts of 88 × 109/l (73 to 101 × 109/l) and 115 × 109/l (95 to 135 × 109/l) for the first and second cycles, respectively. Recovered platelets showed a low basal P-selectin expression at 10.8% (8.1 to 15.2%) and a strong response to thrombin-activating peptide. Leukocyte yield was 93.0% (90.1 to 95.7%) with no activation or cell death. Global removal ratios were 98.3% (97.8 to 98.9%), 98.2% (96.9 to 98.8%), and 88.3% (86.6 to 90.7%) for heparin, albumin, and fibrinogen, respectively. The processing times were 4.4 min (4.2 to 4.6 min) and 4.4 min (4.2 to 4.7 min) for the first and second cycles, respectively. Conclusions This study demonstrated the performance of the SAME device. Platelets and red blood cells were salvaged without significant impact on cell integrity and function. In the meantime, leukocytes were not activated, and the washing quality of the device prevented reinfusion of high concentrations of heparin and plasma proteins. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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Primary lymphedema, a rare disease, has a genetic cause in ~40% of patients. Recently, loss-of-function mutations in PIEZO1, which encodes the mechanotransducer protein PIEZO1, were described as causing primary lymphedema, when gain-of-function PIEZO1 mutations were attributed to dehydrated hereditary stomatocytosis type-1 (DHS), a dominant red cell hemolytic disorder, with ~20% of patients having perinatal edema. Lymphedema was diagnosed in a 36-year-old man from a three-generation DHS family, with a PIEZO1-allele harboring 3 missense mutations in cis. Four affected family members had severe fetal and neonatal edema, most severe in the proband, whose generalized edema with prevailing ascites resolved after 8 months. Our patient's intermittent lower limb-lymphedema episodes during hot periods appeared at puberty; they became persistent and bilateral at age 32. Clinical Stemmer's sign confirmed lymphedema. Lower leg lymphoscintigraphy showed substantial dermal backflow in both calves, predominantly on the right. Noncontrast magnetic resonance lymphography showed bilateral lower limb lymphedema, dilated dysplastic lymphatic iliac, and inguinal trunks. Exome-sequencing analysis identified no additional pathogenic variation in primary lymphedema-associated genes. This is the first description of well-documented lymphedema in an adult with PIEZO1-DHS. The pathophysiology of PIEZO1-associated primary lymphedema is poorly understood. Whether it infers overlapping phenotypes or different mechanisms of gain- and loss-of-function PIEZO1 mutations deserves further investigation.

What is understood as “healing” is often culturally and socially embedded. One’s culture helps to define what it means to be well or unwell, and what it means to heal or recover. Sometimes, one’s culture sits in contrast to the mainstream, western scientific approach to health, often seen as the freedom from illness. A Métis worldview is holistic in itself, and it incorporates notions and practices of well-being that go beyond just being “illness or problem free”. Wellbeing is often directly linked to our relationship with the food that sustains us, to the various animal and plant worlds, to the elements, and to being in “right relationship” to the world and others. Dr. Catherine Richardson Kinewesquao presents an approach to healing which she refers to as transformative, energetic and spiritual. She draws from Cree teachings related to “mamatowisowin”, the life force inherent in all beings and the act of calling forth this energy into the healing process. This life force is connected to dignity, justice and care. Metaphorically, it can be talked about as being released or made available when an individual opens to discussing/facing fears and sorrows, distressing events and losses, and to finding a way to integrate them into their whole being. It is a form of energy transmutation, of becoming more emotionally fluid and liberated from the negativity of what is “acting upon them”. When energy is unblocked or released, particularly in the presence of a compassionate listener, the person may then have more energy for their chosen life projects. By using a response-based approach in the aftermath of violence and degradation, and by contextualizing events through exploratory conversations, one may transform stress into productive energy to fuel life, growth and action. Kinewesquao articulates the use of cultural processes for stress management and working with the natural world to enhance well-being. Ultimately, she makes a case that “positive social responses” (e.g., love, care, compassionate listening, support and cultural rituals) to one’s suffering can be some of the best healing medicines.

International audience; Hereditary xerocytosis is a dominantly inherited red cell membrane disorder caused in most cases by gain-of-function mutations in PIEZO1, encoding a mechanosensitive ion channel that translates a mechanic stimulus into calcium influx. We found that PIEZO1 was expressed early in erythroid progenitor cells, and investigated whether it could be involved in erythropoiesis, besides having a role in the homeostasis of mature red cell hydration. In UT7 cells, chemical PIEZO1 activation using YODA1 repressed glycophorin A expression by 75%. This effect was PIEZO1-dependent since it was reverted using specific short hairpin-RNA knockdown. The effect of PIEZO1 activation was confirmed in human primary progenitor cells, maintaining cells at an immature stage for longer and modifying the transcriptional balance in favor of genes associated with early erythropoiesis, as shown by a high GATA2/GATAI ratio and decreased alpha/beta-globin expression. The cell proliferation rate was also reduced, with accumulation of cells in G0/G1 of the cell cycle. The PIEZO1-mediated effect on UT7 cells required calcium-dependent activation of the NFAT and ERK1/2 pathways. In primary erythroid cells, PIEZO1 activation synergized with erythropoietin to activate STATS and ERK, indicating that it may modulate signaling pathways downstream of erythropoietin receptor activation. Finally, we studied the in-vitro erythroid differentiation of primary cells obtained from 14 PIEZO1-mutated patients, from 11 families, carrying ten different mutations. We observed a delay in erythroid differentiation in all cases, ranging from mild (n=3) to marked (n=8). Overall, these data demonstrate a role for PIEZO1 during erythropoiesis, since activation of PIEZO1 both chemically and through activating mutations - delays erythroid maturation, providing new insights into the pathophysiology of hereditary xerocytosis.

International audience; No abstract available

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Hereditary xerocytosis is a rare red blood cell disease related to gain-of-function mutations in the FAM38A gene, encoding PIEZO1, in 90% of cases. PIEZO1 is a broadly expressed mechano-transducer that plays a major role in many cell systems and tissues that respond to mechanical stress. In erythrocytes, PIEZO1 adapts the intracellular ionic content and cell hydration status to the mechanical constraints induced by the environment. Until recently, the pathophysiology of hereditary xerocytosis was mainly believed to be based on the "PIEZO1-Gardos channel axis" in erythrocytes, according to which PIEZO1-activating mutations induce a calcium influx that secondarily activates the Gardos channel, leading to potassium and water efflux and subsequently to red blood cell dehydration. However, recent studies have demonstrated additional roles for PIEZO1 during early erythropoiesis and reticulocyte maturation as well as roles in other tissues and cells such as lymphatic vessels, hepatocytes, macrophages and platelets that may affect the pathophysiology of the disease. These findings, presented and discussed in this review, broaden our understanding of hereditary xerocytosis beyond that of primarily being a red blood cell disease and identify potential therapeutic targets. This article is protected by copyright. All rights reserved.

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Background Congenital hemolytic anemia constitutes a heterogeneous group of rare genetic disorders of red blood cells. Diagnosis is based on clinical data, family history and phenotypic testing, genetic analyses being usually performed as a late step. In this study, we explored 40 patients with congenital hemolytic anemia by whole exome sequencing: 20 patients with hereditary spherocytosis and 20 patients with unexplained hemolysis. Results A probable genetic cause of disease was identified in 82.5% of the patients (33/40): 100% of those with suspected hereditary spherocytosis (20/20) and 65% of those with unexplained hemolysis (13/20). We found that several patients carried genetic variations in more than one gene (3/20 in the hereditary spherocytosis group, 6/13 fully elucidated patients in the unexplained hemolysis group), giving a more accurate picture of the genetic complexity of congenital hemolytic anemia. In addition, whole exome sequencing allowed us to identify genetic variants in non-congenital hemolytic anemia genes that explained part of the phenotype in 3 patients. Conclusion The rapid development of next generation sequencing has rendered the genetic study of these diseases much easier and cheaper. Whole exome sequencing in congenital hemolytic anemia could provide a more precise and quicker diagnosis, improve patients’ healthcare and probably has to be democratized notably for complex cases.

Severe iron overload is frequent in dehydrated hereditary stomatocytosis (DHSt) despite well-compensated hemolysis and no or little transfusion requirement. We investigated 4 patients with proven DHSt, in whom the degree of hemolysis was closely related to iron status. Genetic modifiers increasing iron stores (HFE:pCys282Tyr, HAMP:c-153C>T mutations) were accompanied with high liver iron concentrations and increased hemolysis, whereas therapeutic phlebotomies alleviated the hemolytic phenotype. There were no manifestations of hemolysis in one patient with low iron stores. Hemolysis reappeared when iron supplementation was given. The search for genetic or acquired modifiers of iron status and the modulation of iron stores may help in the management of these patients.

31st International Symposium of the International-Society-for-Laboratory-Hematology (ISLH) on Technological Innovations in Laboratory Hematology, Brussels, BELGIUM, 2018; International audience; Hydration status is critical for erythrocyte survival and is mainly determined by intracellular cation content. Active pumps, passive transporters, and ion channels are the key components of volume homeostasis, whereas water passively fits ionic movements. Whenever cation content increases, erythrocyte swells, whereas it shrinks when cation content decreases. Thus, inappropriate cation leak causes erythrocyte hydration disorders, hemolytic anemia, and characteristic red cell shape abnormalities named stomatocytosis. All types of stomatocytosis either overhydrated or dehydrated are linked to inherited or de novo mutations in genes encoding ion transporters or channels. Although intracellular ion content can be assessed by experimental methods, laboratory diagnosis is guided by a combination of red blood cell parameters and deformability measurement when possible, and confirmed by sequencing of the putative genes. A better knowledge of the mechanisms underlying erythrocyte hydration imbalance will further lead to therapeutic improvements.

International audience; We describe the clinical, hematologic and genetic characteristics of a retrospective series of 126 subjects from 64 families with hereditary xerocytosis. Twelve patients from six families carried a KCNN4 mutation, five had the recurrent p.Arg352His mutation and one had a new deletion at the exon 7-intron 7 junction. Forty-nine families carried a PIEZO1 mutation, which was a known recurrent mutation in only one-third of the cases and private sequence variation in others; 12 new probably pathogenic missense mutations were identified. The two dominant features leading to diagnosis were hemolysis that persisted after splenectomy and hyperferritinemia, with an inconstant correlation with liver iron content assessed by magnetic resonance imaging. PIEZO1-hereditary xerocytosis was characterized by compensated hemolysis in most cases, perinatal edema of heterogeneous severity in more than 20% of families and a major risk of post-splenectomy thrombotic events, including a high frequency of portal thrombosis. In KCNN4-related disease, the main symptoms were more severe anemia, hemolysis and iron overload, with no clear sign of red cell dehydration; therefore, this disorder would be better described as a ‘Gardos channelopathy’. These data on the largest series to date indicate that PIEZO1-hereditary xerocytosis and Gardos channelopathy are not the same disease although they share hemolysis, a high rate of iron overload and inefficient splenectomy. They demonstrate the high variability in clinical expression as well as genetic bases of PIEZO1-hereditary xerocytosis. These results will help to improve the diagnosis of hereditary xerocytosis and to provide recommendations on the clinical management in terms of splenectomy, iron overload and pregnancy follow-up.

Introduction: Southeast Asian Ovalocytosis is a dominantly inherited pathology due to a red blood cell membrane abnormal band 3 protein which is prevalent in Southeast Asia. It is associated with no clinical manifestations or induced hemolytic anemia. Case Report: We report herein a case of a 30 years old patient with both Southeast Asian Ovalocytosis and sickle cell trait who had three splenic infarctions without hypoxic situation. Since the last episode, there was no anemia and reticulocyte count and bilirubin reached normal levels. Conclusion: This abnormal band 3 protein lead to a red blood cell deshydratation which could explain polymerization of HbS and clinical manifestations. Only one case of a retinal stroke in a patient from the Comoros Islands with both Southeast Asian Ovalocytosis and a sickle cell trait has been previously reported in 2009. Splenic infarctions could be therefore another clinical manifestation of this association.

In order to identify very early prognostic factors that can provide insights into subsequent clinical complications, we performed a comprehensive longitudinal multi-center cohort study on 57 infants with sickle cell anemia (55 SS; 2 Sβ°) during the first 2 years of life (ClinicalTrials.gov: NCT01207037). Time to first occurrence of a severe clinical event-acute splenic sequestration (ASS), vaso-occlusive (VOC) event requiring hospitalization, transfusion requirement, conditional/ abnormal cerebral velocities, or death-was used as a composite endpoint. Infants were recruited at a mean age of 4.4 ±1 months. Median follow-up was 19.4 months. During the study period, 38.6% of infants experienced ≥1 severe event: 14% ASS, 22.8% ≥ 1 VOC (median age: 13.4 and 12.8 months, respectively) and 33.3% required transfusion. Of note, 77% of the cohort was hospitalized, with febrile illness being the leading cause for admission. Univariate analysis of various biomarkers measured at enrollment showed that fetal hemoglobin (HbF) was the strongest prognostic factor of subsequent severe outcome. Other biomarkers measured at enrolment including absolute neutrophil or reticulocyte counts, expression of erythroid adhesion markers, % of dense red cells, cellular deformability or ϒ-globin genetic variants, failed to be associated with severe clinical outcome. Multivariate analysis demonstrated that higher Hb concentration and HbF level are two independent protective factors (adjusted HRs (95% CI) 0.27 (0.11-0.73) and 0.16 (0.06-0.43), respectively). These findings imply that early measurement of HbF and Hb levels can identify infants at high risk for subsequent severe complications, who might maximally benefit from early disease modifying treatments.

Non-immune hemolytic anemia (NIHA) is characterized by positive routine hemolytic tests but negative anti-human immunoglobulin (Coombs) test. Hereditary non-immune hemolysis includes disorders of erythrocytic enzymes, membrane, hemoglobin (qualitative and quantitative disorders), as well as the rare hereditary forms of thrombotic microangiopathies. Acquired NIHA includes paroxysmal nocturnal hemolysis (PNH), infections, drug and metal intoxications with as a target red blood cells or endothelium of capillaries, the rare acquired forms of thalassemia or erythrocytic membrane disorders, and hemolysis secondary to a dysfunctioning artificial (prosthetic) cardiac valve. Identification of the specific cause of NIHA is sometimes difficult and requires not only a good knowledge of this entity but mainly a qualified specialized hematologic laboratory. An algorithm to be used in every new patient consulting for NIHA is proposed in the last part of this article.

Key Clinical Message Infantile pyknocytosis is a rare cause of neonatal jaundice and hemolytic anemia. We report on two cases in twin girls that were diagnosed on peripheral blood smear reading. Pyknocytosis should be considered in cases of early unexplained severe hemolytic anemia, and systematic peripheral smear review performed. Its management consists of phototherapy and RBC transfusion.

To the editor: Red cells of patients with hereditary spherocytosis (HS) have a decreased surface-to-volume ratio,[1][1] leading to their trapping and destruction during their passage through the splenic cords.[2][2][⇓][3]-[4][4] Therefore, surgical total splenectomy (TS) by removing the main site

Le théâtre de Baelo Claudia a principalement connu deux phases de construction, qui nécessitent diverses explications : l’une dans les dernières années du règne de Néron et l’autre au tout début de l’époque flavienne. Elles font partie de l’important programme de rénovation qui modifia profondément la physionomie de l’équipement public du municipe durant la seconde moitié du 1er s. En el teatro romano de Baelo Claudia se identifican, principalmente, dos fases constructivas que son susceptibles de diferentes interpretaciones. La primera de ellas corresponde al final del reinado de Nerón; la segunda, a comienzos de la época flavia. Ambas pueden enmarcarse dentro del importante programa de renovación encargado de transformar profundamente la fisionomía de los ámbitos públicos del municipio durante la segunda mitad del siglo I. In the Roman theatre at Baelo Claudia two main phases of construction have been identified, both susceptible of different interpretations. The first belongs to the 6th decade of the 1st century CE; the second, to the beginning of the Flavian period. Both were part of a major renovation programme intended to transform the appearance of the town’s public spaces during the second half of the 1st century.

Summary Background Heparin and its analogs, mediating their anticoagulant activity through antithrombin (AT) activation, remain largely used for the preventive and curative treatment of thrombosis. The major adverse reaction of these drugs is the bleeding risk associated with overdose. Unfractionnated heparin (UFH) can be efficiently and rapidly neutralized by protamine sulfate, but this reversal partially neutralizes low-molecular-weight heparin (LMWH) and is inefficient in reversing fondaparinux. To secure administration of AT-mediated anticoagulants and counteract bleeding disorders, we previously designed a recombinant inactive AT as an antidote to heparin derivatives. Objectives To get around the limited production level of recombinant AT, we propose in this study an alternative strategy to produce a chemically modified inactive AT, exhibiting increased heparin affinity, as an antagonist of heparin analogs. Methods Plasma-derived AT was chemically modified with 2,3 butanedione, a diketone known to specifically react with the arginine side chain. The chemical reaction was conducted in the presence of heparin to preserve basic residues within the heparin binding site from modifications. Results AT treated by butanedione and selected for its high heparin affinity (AT-BD) was indeed modified on reactive Arg393 and thus exhibited decreased anticoagulant activity and increased heparin affinity. AT-BD was able to neutralize anticoagulant activity of heparin derivatives in vitro and in vivo and was devoid of intrinsic anticoagulant activity, as assessed by activated partial thromboplastin time assay. Conclusions AT-BD appears to be as efficient as protamine to neutralize UFH in vivo but could be more largely used because it also reverses fondaparinux and LMWH.

SummaryInherited quantitative (type I) or qualitative (type II) antithrombin deficiency (ATD) due to mutations in the SERPINC1 gene is a well-known risk factor for venous thromboembolism. ATD may also increase risk for arterial thrombosis. Few studies have investigated risk for thrombosis according to mutations. We addressed this topic in a large retrospective cohort study of 540 heterozygous carriers of SERPINC1 mutations and compared risk for first venous or arterial thrombosis associated with carrying of different type II or type I mutations. No clear difference in risk for first venous thrombotic event was observed among type I (missense or null), type IIRS or type IIPE mutation carriers except for a few variants that displayed lower risk [all events, adjusted relative risk: Cambridge II: 0.42 (95%CI 0.25–0.70), Dublin: 0.35 (95%CI 0.13–0.99)]. IIHBS mutation carrying was associated with a clearly lower risk than type I mutation carrying [0.28 (95%CI 0.20–0.40)]. These differences in risk were observed for both all venous thrombotic events and pulmonary embolism associated with deep venous thrombosis. The HBS group was also heterogeneous, with AT Budapest 3 carriers displaying a non-significantly different risk [0.61 (95%CI 0.31–1.20)] compared to type I mutation carriers. We also studied risk for arterial thrombosis and found no significant influence of mutation type. Altogether, our findings suggest a place for SERPINC1 genotyping in the diagnosis of ATD.Supplementary Material to this article is available online at www.thrombosis-online.com.

L’ouverture d’une première tranchée de sondage dans la cour intérieure du château de Morlanne en 2012 a permis de mettre au jour une maçonnerie en pierres manifestement antérieure au château actuel sur laquelle viennent se rattacher deux tronçons de mur construits en briques et/ou pierres plates. Mais la petitesse de la tranchée ne permettait pas d’extrapoler sur la disposition de ces maçonneries. Si l’ouverture d’un second sondage à l’intérieur du corps de logis n’a pas permis de mettre au jour d’autres maçonneries, elle a offert l’opportunité de confirmer la présence de l’argile rapportée constituant la motte primitive. C’est la décision de remplacer le pavement de la cour qui a motivé l’emplacement de sondages périphériques, lesquels ont permis la découverte de maçonneries très importantes situées sous le seuil du logis seigneurial. Cette découverte a motivé une petite fouille en urgence pour relever, topographier les maçonneries mises au jour. Le bâtiment datant du XIVe siècle a subi plusieurs restructurations au cours des siècles avant que M et Mme Ritter, propriétaires privés, lui redonnent un caractère de forteresse médiévale. L’opération d’archéologie du bâti permet d’’identifier les époques de restructuration grâce à la nature des matériaux utilisés, les largeurs d’ouvertures, les formes des ouvertures, les cheminées. Le décrépissage des murs a permis de faire des observations sur les matériaux utilisés dans la construction de l’enceinte et de la façade donnant sur la cour intérieure. Pour le premier étage, il est possible de restituer l’éclairage de la grande salle d’honneur du XIVe siècle par des fenêtres en plein cintre. Il est maintenant établi, grâce à l’étude de bâti, que le percement de l’entrée occidentale du château est largement postérieur à l’époque médiévale. L’étude de bâti et la fouille ont donc permis de renouveler complètement nos connaissances sur ce château et d’émettre de nouvelles hypothèses sur la construction antérieure à la réalisation de Gaston Fébus.

To the editor: Southeast Asian ovalocytosis (SAO) is caused by a heterozygous 27-nucleotide deletion in SLC4A1 coding for band 3, the anion-exchange protein of the red cell membrane.[1][1][⇓][2]-[3][3] This asymptomatic dominant trait is considered as a host genetic adaptation to malaria in

The aim of the study was to evaluate the influence of the MDR1 C3435T polymorphism on the therapeutic response in 23 patients treated with cetuximab plus irinotecan for irinotecan refractory liver metastatic colorectal cancer considering their KRAS status. Indeed, irinotecan and its active metabolite (SN-38) are both substrates of P-glycoprotein (P-gp) encoded by MDR1. Patients received cetuximab and irinotecan up to progression. The overall survival was 55% at 10 months. Overall, four patients had an undetermined KRAS status and two patients with mutated KRAS were in progression disease. The response to treatment was observed after 3 months among the 17 wild-type KRAS patients. Two patients presented a progressive disease (1 TT and 1 CT), eight patients had a stable disease (5 CC and 3CT) and five patients had a partial response (3 CC and 2 CT). Importantly, 2 patients (2 TT) were in complete response and still alive 5 years after starting the treatment, which suggests that the combination of wild-type KRAS and MDR1 3435 TT may be a factor of good prognosis. These results suggest that EGFR inhibition by cetuximab may overcome this irinotecan resistance by abrogating drug efflux depending on MDR1 3435 polymorphism. Among patients resistant to irinotecan, it is still possible to use the association of cetuximab plus irinotecan to obtain a complete resection of hepatic metastases that is necessary to improve their survival.

Prolonged cannabis use has a significant impact on health and well-being. Genetic factors are known to influence cannabis dependence, but few specific genetic markers have been identified. ABCB1 polymorphisms are known to modify drug pharmacokinetics but have yet to be studied for their role in generating and maintaining cannabis dependence. The objective of this study is to determine if ABCB1 C3435T polymorphism may represent an independent genetic marker for cannabis dependence risk. An open bi-centric association study was conducted in two French Addiction Centres. Caucasian patients diagnosed with isolated cannabis dependence were compared with healthy age-matched controls for socio-demographic, clinical and genetic data using chi-square test, Fisher's exact test, or Mann-Whitney U test. Independent association between ABCB1 C3435T SNP marker and cannabis dependence was evaluated using multiple logistic regression analysis. Versus controls (n=40), patients with cannabis dependence (n=40) had a significantly higher 3435C allele frequency (62.5% versus 43.8% respectively, P=0.017) and CC genotype (50% versus 20%, P=0.005, OR=4.00 [1.50-10.60]). Multiple logistic regression analysis of the C3435T SNP and variables identified in univariate analyses indicated that the CC genotype was independently associated with cannabis dependence (P=0.045, OR=6.61 [1.05-46.58]). This is the first time a significant specific genetic marker has been shown in cannabis dependence. ABCB1 polymorphisms may alter Delta9THC distribution, its psychoactive effects and individual vulnerability to dependence. These results pave the way to a new pharmacogenetic hypothesis in cannabis dependence.