Occupational Exposure to Ultrafine Particles and Placental Histopathological Lesions: A Retrospective Study about 130 Cases.

Ultrafine particles (UFPs) are particles smaller than 100 nanometers that are produced unintentionally during human activities or natural phenomena. They have a higher biological reactivity than bigger particles and can reach the placenta after maternal exposure. One study has shown an association between maternal occupational exposure to UFPs and fetal growth restriction. Yet few studies have focused on the effects of UFP exposure on placental histopathological lesions. The aim of this study was to investigate the association between maternal occupational exposure to UFPs and histopathological lesions of their placenta. The analyses were based on data from the ARTEMIS Center. A job-exposure matrix was used to assess occupational exposure to UFPs. The histopathological placental exam was performed by two pathologists who were blinded to the exposure of each subject. The examination was conducted in accordance with the recommendations of the Amsterdam consensus. The study sample included 130 placentas (30 exposed, 100 unexposed). Maternal occupational exposure to UFPs during pregnancy is significantly associated with placental hypoplasia (the phenomenon affected 61% of the exposed patients and 34% of the unexposed ones, p < 0.01). Further research is needed to explain its pathophysiological mechanisms.

p57-discordant villi in hydropic products of conception: a clinicopathological study of 70 cases.

p57 immunostaining is performed on hydropic products of conception to diagnose hydatidiform moles (HMs), which can progress to gestational trophoblastic neoplasia. Partial hydatidiform mole (PHM) and hydropic abortion (HA) display positive staining in stromal and cytotrophoblastic cells, whereas complete hydatidiform mole (CHM) is characterized by loss of p57 expression in both cell types. In some cases, an aberrant pattern is observed, called discordant p57 expression, with positive cytotrophoblast staining and negative stromal staining, or vice versa. The aim of this study was to describe the clinical, biological, and pathological characteristics of p57-discordant villi (p57DV) and other associated populations in cases of divergent p57 expression and to compare the evolutions of p57DV-associated and classic CHMs. Seventy cases of p57DV diagnosed by referent pathologists were divided into two groups, G1: p57DV ± non-CHM component (n = 22) and G2: p57DV + CHM component (n = 48). p57DV morphology was similar in the two groups. Observation of more than two populations and hybrid villi on p57 immunostaining were significantly more frequent in G2. The clinical, ultrasound, and biological presentations of p57DV-associated and classic CHMs were similar. The initial pathological diagnosis was more frequently incorrect, missing the CHM component, for the p57DV-associated CHMs. Molecular genotyping was informative in seven cases and identified as androgenetic/biparental mosaicism in four cases. These results show that p57DV are a diagnostic challenge for pathologists and that most are associated with a CHM component. However, the clinical management of p57DV-associated CHMs should be the same as that of classic CHMs.

TAR syndrome: Clinical and molecular characterization of a cohort of 26 patients and description of novel noncoding variants of RBM8A.

Thrombocytopenia-absent radius (TAR) syndrome is characterized by radial defect and neonatal thrombocytopenia. It is caused by biallelic variants of RBM8A gene (1q21.1) with the association of a null allele and a hypomorphic noncoding variant. RBM8A encodes Y14, a core protein of the exon junction complex involved in messenger RNA maturation. To date, only two hypomorphic variants have been identified. We report on a cohort of 26 patients affected with TAR syndrome and carrying biallelic variants in RBM8A. Half patients carried a 1q21.1 deletion and one of the two known hypomorphic variants. Four novel noncoding variants of RBM8A were identified in the remaining patients. We developed experimental models enabling their functional characterization in vitro. Two variants, located respectively in the 5'-untranslated region (5'-UTR) and 3'-UTR regions, are responsible for a diminished expression whereas two intronic variants alter splicing. Our results bring new insights into the molecular knowledge of TAR syndrome and enabled us to propose genetic counseling for patients' families.

Foetal onset of EIF2B related disorder in two siblings: cerebellar hypoplasia with absent Bergmann glia and severe hypomyelination.

Bi-allelic pathogenic variants in genes of the EIF2B family are responsible for Childhood Ataxia with Central nervous system Hypomyelination/Vanishing White Matter disease, a progressive neurodegenerative disorder of the central white matter. Only seven molecularly proven cases with antenatal onset have been reported so far. We report for the first time the neuropathological findings obtained from two foetuses harbouring deleterious variants in the EIF2B5 gene who presented in utero growth retardation and microcephaly with simplified gyral pattern that led to a medical termination of the pregnancy at 27 and 32 weeks of gestation. Neuropathological examination confirmed microcephaly with delayed gyration, periventricular pseudo-cysts and severe cerebellar hypoplasia. Histologically, the cerebellar cortex was immature, the dentate nuclei were fragmented and myelin stains revealed almost no myelination of the infratentorial structures. Bergmann glia was virtually absent associated to a drastic decreased number of mature astrocytes in the cerebellar white matter, multiple nestin-positive immature astrocytes as well as increased numbers of PDGRFα-positive oligodendrocyte precursors. Whole exome sequencing performed in the two foetuses and their parents allowed the identification of two EIF2B5 compound heterozygous variants in the two foetuses: c.468C > G p.Ile156Met and c.1165G > A p.Val389Met, the parents being heterozygous carriers. These variants are absent in the genome Aggregation Database (gnomAD r2.0.2). Contrary to the variant Ile156Met already described in a patient with CACH syndrome, the variant p.Val389Met is novel and predicted to be deleterious using several softwares. Neuropathological findings further expand the phenotypic spectrum of the disease that very likely occurs during early gestation and may manifest from the second half of pregnancy by a severe impairment of cerebral and cerebellar development.

Human interleukin-2 receptor ß mutations associated with defects in immunity and peripheral tolerance.

Interleukin-2, which conveys essential signals for immunity, operates through a heterotrimeric receptor. Here we identify human interleukin-2 receptor (IL-2R) ß chain (IL2RB) gene defects as a cause of life-threatening immune dysregulation. We report three homozygous mutations in the IL2RB gene of eight individuals from four consanguineous families that cause disease by distinct mechanisms. Nearly all patients presented with autoantibodies, hypergammaglobulinemia, bowel inflammation, dermatological abnormalities, lymphadenopathy, and cytomegalovirus disease. Patient T lymphocytes lacked surface expression of IL-2Rß and were unable to respond to IL-2 stimulation. By contrast, natural killer cells retained partial IL-2Rß expression and function. IL-2Rß loss of function was recapitulated in a recombinant system in which IL2RB mutations caused reduced surface expression and IL-2 binding. Stem cell transplant ameliorated clinical symptoms in one patient; forced expression of wild-type IL-2Rß also increased the IL-2 responsiveness of patient T lymphocytes in vitro. Insights from these patients can inform the development of IL-2-based therapeutics for immunological diseases and cancer.

Bardet-Biedl syndrome: Antenatal presentation of forty-five fetuses with biallelic pathogenic variants in known Bardet-Biedl syndrome genes.

Bardet-Biedl syndrome (BBS) is an emblematic ciliopathy associated with retinal dystrophy, obesity, postaxial polydactyly, learning disabilities, hypogonadism and renal dysfunction. Before birth, enlarged/cystic kidneys as well as polydactyly are the hallmark signs of BBS to consider in absence of familial history. However, these findings are not specific to BBS, raising the problem of differential diagnoses and prognosis. Molecular diagnosis during pregnancies remains a timely challenge for this heterogeneous disease (22 known genes). We report here the largest cohort of BBS fetuses to better characterize the antenatal presentation. Prenatal ultrasound (US) and/or autopsy data from 74 fetuses with putative BBS diagnosis were collected out of which molecular diagnosis was established in 51 cases, mainly in BBS genes (45 cases) following the classical gene distribution, but also in other ciliopathy genes (6 cases). Based on this, an updated diagnostic decision tree is proposed. No genotype/phenotype correlation could be established but postaxial polydactyly (82%) and renal cysts (78%) were the most prevalent symptoms. However, autopsy revealed polydactyly that was missed by prenatal US in 55% of the cases. Polydactyly must be carefully looked for in pregnancies with apparently isolated renal anomalies in fetuses.

Fraser syndrome: features suggestive of prenatal diagnosis in a review of 38 cases.

OBJECTIVE: Fraser syndrome (FS) is a rare malformation recessive disorder. Major criteria are cryptophtalmos, syndactyly, respiratory, genital and urinary tract anomalies. Few prenatal presentations have been reported. METHOD: We analyzed the prenatal and postnatal fetal phenotype in 38 cases of FS, including 25 pregnancy termination cases, 8 intra-uterine death cases and 4 cases that died after birth. RESULTS: Including both prenatal and postnatal fetal phenotypic evaluation, all cases presented dysmorphic features with nose and ear dysplasia. Renal anomalies and syndactyly were present in 37/38 cases, cryptophtalmos in 36/38, airways anomalies in 30/37 and genital anomalies in 30/35 cases. Anomalies of the abdominal wall such as low set umbilicus and omphalocele were found in 31 cases. Among the 26 cases for which ultrasound data were available, detectable anomalies included oligohydramnios (22), ascites/hydrops (9), renal anomalies (20), evidence for high airways obstruction (11), ophthalmologic anomalies (4), ear dysplasia (2) and syndactyly (2). CONCLUSION: This study shows that the postnatal phenotype of FS is very specific, whereas oligohydramnios hampers the prenatal recognition of the cardinal FS diagnosis criteria. Association of oligohydramnios, kidney agenesis and CHAOS should lead to consider this diagnosis. © 2016 John Wiley & Sons, Ltd.

Severe X-linked chondrodysplasia punctata in nine new female fetuses.

OBJECTIVES: Conradi-Hünermann-Happle [X-linked dominant chondrodysplasia punctata 2 (CDPX2)] syndrome is a rare X-linked dominant skeletal dysplasia usually lethal in men while affected women show wide clinical heterogeneity. Different EBP mutations have been reported. Severe female cases have rarely been reported, with only six antenatal presentations. METHODS: To better characterize the phenotype in female fetuses, we included nine antenatally diagnosed cases of women with EBP mutations. All cases were de novo except for two fetuses with an affected mother and one case of germinal mosaicism. RESULTS: The mean age at diagnosis was 22 weeks of gestation. The ultrasound features mainly included bone abnormalities: shortening (8/9 cases) and bowing of the long bones (5/9), punctuate epiphysis (7/9) and an irregular aspect of the spine (5/9). Postnatal X-rays and examination showed ichthyosis (8/9) and epiphyseal stippling (9/9), with frequent asymmetric short and bowed long bones. The X-inactivation pattern of the familial case revealed skewed X-inactivation in the mildly symptomatic mother and random X-inactivation in the severe fetal case. Differently affected skin samples of the same fetus revealed different patterns of X-inactivation. CONCLUSION: Prenatal detection of asymmetric shortening and bowing of the long bones and cartilage stippling should raise the possibility of CPDX2 in female fetuses, especially because the majority of such cases involve de novo mutations.

[Incidental intraplacental gestational choriocarcinoma on a full-term placenta]. / Choriocarcinome gestationnel intra-placentaire de découverte fortuite sur un placenta à terme.

Of all the gestational trophoblastic tumors, the gestational choriocarcinomas have the worst prognosis and the most uncommon. We report a case diagnosed on a full-term placenta, discovered incidentally. The patient, gravida 2, para 1, delivered a hypotrophic infant at 38 weeks gestation. The placenta was examined in the laboratory to perform anatomo-pathological examination in order to explain the growth retardation. This study revealed the presence of an intraplacental choriocarcinoma. Disease staging was negative for both mother and child, and beta-HCG levels remained at zero. These two factors are rather good prognosis for choriocarcinoma. With this observation, we highlight the added-value of placental examination, which seems essential for any fetal pathology, pathological pregnancy and intrapartum complications. Anatomo-pathological examination must be meticulous and systematized in order to not overlook an intraplacental tumor.

[Placental pathology of uteroplacental vascular deficiency]. / Anatomie pathologique de l'insuffisance vasculaire utéroplacentaire.

The indications of the pathological examination of the placenta are mainly represented by uteroplacental vascular deficiency. The clinical context is often evocative, but it can sometimes be solely an intra-uterine growth retardation or an unexplained in utero fetal death. So, the pathological lesions of this uteroplacental vascular deficiency must be well-known to be correctly interpreted, for none of these lesions is truly specific. The pathological diagnosis is based on a group of macroscopic and microscopic arguments. Various physiopathological mechanisms, often imperfectly known, can be at the origin of an uteroplacental vascular insufficiency, but in the current position, the pathological examination does not allow etiopathogenic orientation. The development of the trophoblastic biopsies gives us access to a new material which, in parallel with the cytogenetic analysis, often allows us, in front of an unexplained intra-uterine growth retardation, to direct the diagnosis towards uteroplacental vascular insufficiency. The histological analysis of the chorionic villous sampling taken precociously during pathological pregnancies is thus a major diagnostic contribution. But especially, this analysis gives access to new information which, in the near future, will enable us to better define the pathological evolution of the lesions of hypoxic chorionic villous and to contribute to a better knowledge of this pathology which, under many aspects, still conceals many mysteries.

Reduced placental telomere length during pregnancies complicated by intrauterine growth restriction.

OBJECTIVES: Recent studies have shown that telomere length was significantly reduced in placentas collected at delivery from pregnancies complicated by intrauterine growth restriction secondary to placental insufficiency. Placental telomere length measurement during ongoing pregnancies complicated by intrauterine growth restriction has never been reported. This was the main objective of our study. METHODS: In our center, late chorionic villus samplings were performed between 18 and 37 weeks of amenorrhea in 24 subjects with severe intrauterine growth restriction (cases) and in 28 subjects with other indications for prenatal diagnosis (controls). Placental insufficiency was assessed by histo-pathological examination. Relative measurement of telomere length was carried out prospectively by quantitative Fluorescent In Situ Hybridization using fluorescent Peptide Nucleic Acid probes on interphase nuclei obtained from long-term cultured villi and with an automated epifluorescent microscope. A quantitative Polymerase Chain Reaction technique was performed to confirm the quantitative Fluorescent In Situ Hybridization results. The number of copies of gene loci encoding the RNA template (hTERC) and the catalytic subunit (hTERT) of the enzyme complex telomerase were also estimated in these placentas by Fluorescent In Situ Hybridization. RESULTS: Mean fluorescence intensity of telomere probes estimated by quantitative Fluorescent In Situ Hybridization was significantly less for cases compared to controls (p<0.001). This result indicated that mean telomere length was significantly reduced in placentas during pregnancies complicated by intrauterine growth restriction. Reduced telomere length was confirmed by the quantitative Polymerase Chain Reaction technique. No copy number variation of the hTERC and hTERT loci was noticed for cases, or for controls. CONCLUSION: This study clearly demonstrates a reduction of placental telomere length in ongoing pregnancies (from 18 to 37 weeks of amenorrhea) complicated by severe intrauterine growth restriction secondary to placental insufficiency.

Cobblestone lissencephaly: neuropathological subtypes and correlations with genes of dystroglycanopathies.

Cobblestone lissencephaly represents a peculiar brain malformation with characteristic radiological anomalies, defined as cortical dysplasia combined with dysmyelination, dysplastic cerebellum with cysts and brainstem hypoplasia. Cortical dysplasia results from neuroglial overmigration into the arachnoid space, forming an extracortical layer, responsible for agyria and/or 'cobblestone' brain surface and ventricular enlargement. The underlying mechanism is a disruption of the glia limitans, the outermost layer of the brain. Cobblestone lissencephaly is pathognomonic of a continuum of autosomal recessive diseases with cerebral, ocular and muscular deficits, Walker-Warburg syndrome, muscle-eye-brain and Fukuyama muscular dystrophy. Mutations in POMT1, POMT2, POMGNT1, LARGE, FKTN and FKRP genes attributed these diseases to α-dystroglycanopathies. However, studies have not been able to identify causal mutations in the majority of patients and to establish a clear phenotype/genotype correlation. Therefore, we decided to perform a detailed neuropathological survey and molecular screenings in 65 foetal cases selected on the basis of histopathological criteria. After sequencing the six genes of α-dystroglycanopathies, a causal mutation was observed in 66% of cases. On the basis of a ratio of severity, three subtypes clearly emerged. The most severe, which we called cobblestone lissencephaly A, was linked to mutations in POMT1 (34%), POMT2 (8%) and FKRP (1.5%). The least severe, cobblestone lissencephaly C, was linked to POMGNT1 mutations (18%). An intermediary type, cobblestone lissencephaly B, was linked to LARGE mutations (4.5%) identified for the first time in foetuses. We conclude that cobblestone lissencephaly encompasses three distinct subtypes of cortical malformations with different degrees of neuroglial ectopia into the arachnoid space and cortical plate disorganization regardless of gestational age. In the cerebellum, histopathological changes support the novel hypothesis that abnormal lamination arises from a deficiency in granule cells. Our studies demonstrate the positive impact of histoneuropathology on the identification of α-dystroglycanopathies found in 66% of cases, while with neuroimaging criteria and biological values, mutations are found in 32-50% of patients. Interestingly, our morphological classification was central in the orientation of genetic screening of POMT1, POMT2, POMGNT1, LARGE and FKRP. Despite intensive research, one-third of our cases remained unexplained; suggesting that other genes and/or pathways may be involved. This material offers a rich resource for studies on the affected neurodevelopmental processes of cobblestone lissencephaly and on the identification of other responsible gene(s)/pathway(s).

Contribution of referent pathologists to the quality of trophoblastic diseases diagnosis.

OBJECTIVE: To evaluate the contribution of referent pathologists (RPs) to the quality of diagnosis of trophoblastic diseases and to study the level of diagnostic agreement between the initial pathologists and the RPs. METHODS: This observational retrospective study was carried between 1 November 1999 and 11 January 2011 using the database of the French Trophoblastic Disease Reference Centre in Lyon. All files for hydatiform moles (HMs), trophoblastic tumours and non-molar pregnancies for which there was an initial suspicion of trophoblastic disease were included, whenever there was rereading of the slides by an RP. A total of 1851 HMs and 150 gestational trophoblastic tumours were analysed. RESULTS: When the initial pathologist diagnosed a complete mole, the RP confirmed the diagnosis in 96% of cases. When the initial pathologist diagnosed a partial mole, the RP confirmed the diagnosis in only 64% of cases. For trophoblastic tumours, when the initial pathologist diagnosed a choriocarcinoma, the RP confirmed the diagnosis in 86% of cases. When the initial anatomopathology suggested an invasive mole, the diagnosis was confirmed in 96% of cases. Finally, when the initial diagnosis was a placental site trophoblastic tumour or an epithelioid trophoblastic tumour, the RP confirmed the diagnosis in 60 and 100% of cases, respectively. CONCLUSION: A systematic policy of rereading of slides for all suspicious moles improves the quality of management of trophoblastic diseases at a national level.

[Maze-like vascular anomaly in partial mole. Interest for the pathological diagnosis of partial mole on chorionic villous sampling]. / Aspect labyrinthique des vaisseaux villositaires dans les môles partielles. Intérêt pour le diagnostic anatomopathologique de môle partielle sur biopsie de villosités choriales.

A case of maze-like angiomatoid anomaly in villi obtained by chorionic villous sampling (CVS) is described. This feature is pathognomonic of partial mole (triploid syndrome) and it was later confirmed by chromosomal analysis. Maze-like angiomatoid anomaly was previously described on specimen submitted after spontaneous or induced abortions, but it was never reported on CVS. This report emphasized that microscopic investigation of CVS cannot be conclusive for cytogenetic anomaly in almost all cases excepted for partial mole where diagnosis criteria are usually characteristic.

[Advantages and limitations of chorionic villous sampling]. / Intérêt et limites de l'examen histopathologique des biopsies de villosités choriales.

Chorionic villous sampling (CVS) has been available for more than twenty years. Together with amniocentesis, it helps the cytogenetician to determine the fetal karyotype for prenatal diagnosis. The choice between these two methods depends on the team and the indication. CVS can now provide sufficient material for both histopathologic and cytogenetic analyses. We evaluated the accuracy of microscopic examination of CVS for detecting primary ovular, uteroplacental vascular (preeclampsia) and inflammatory disorders. Four hundred CVS were examined in the pathology laboratory of Pellegrin Hospital, Bordeaux, France, from January 1995 to February 2008. The results were analyzed according to the indication, the karyotype, the results of placental examination, pregnancy outcome and, when available (following spontaneous or medical termination), fetoplacental findings. The sample was representative of patients requiring CVS for prenatal diagnosis, with respect to maternal age, the stage of pregnancy, and the indications. When used to screen for preeclamsia (prevalence 29.6% in the sample), the sensitivity and specificity of placental biopsy were respectively 56.8% and 87.2% (76.9% in case of intra-uterine growth retardation). When used to screen for chromosomal aberrations (prevalence 7.4%), the specificity was 14.3% and the sensitivity 93.2%. The prevalence of other disorders, and particularly chronic intervillitis, was too low for meaningful analysis. This study shows that histopathologic analysis of chorionic villous samples is useful for detecting the utero-placental vascular origin of intrauterine growth retardation in the absence of other clinical, biological or ultrasound signs, and that it is complementary to cytogenetic analysis. Being a simple and inexpensive examination, histopathologic analysis of CVS could be performed systematically in this indication. Its value and diagnostic signs in other settings need to be determined in larger series.

Genetic rescue of Cdk4 null mice restores pancreatic beta-cell proliferation but not homeostatic cell number.

Lack of Cdk4 expression in mice leads to insulin-deficient diabetes and female infertility owing to a reduced number of pancreatic beta cells and prolactin-producing pituitary lactotrophs, respectively. Cdk4 null mice display also reduced body and organ size. Here, we show that Cdk4 is essential for the postnatal proliferation of pancreatic beta cells but not for embryonic neogenesis from ductal epithelial cells. Re-expression of endogenous Cdk4 in beta cells and in the pituitary gland of Cdk4 null mice restores cell proliferation and results in fertile and normoglycemic animals, thus, demonstrating that the proliferation defects in these cellular populations are cell autonomous because of the lack of Cdk4 expression. However, these mice remain small in size, indicating that this phenotype is not because of pancreatic- or pituitary-mediated endocrine defects. This phenotype is a consequence of reduced cell numbers rather than reduced cell size. Thus, mammalian Cdk4 is not only involved in controlling proliferation of specific cell types but may play a wider role in establishing homeostatic cell numbers.