| 1. |
- Braekeveldt, N., et al.
(författare)
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Patient-Derived Xenograft Models Reveal Intratumor Heterogeneity and Temporal Stability in Neuroblastoma
- 2018
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Ingår i: Cancer Research. - 0008-5472. ; 78:20, s. 5958-5969
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Tidskriftsartikel (refereegranskat)abstract
- Patient-derived xenografts (PDX) and the Avatar, a single PDX mirroring an individual patient, are emerging tools in preclinical cancer research. However, the consequences of intratumor heterogeneity for PDX modeling of biomarkers, target identification, and treatment decisions remain under-explored. In this study, we undertook serial passaging and comprehensive molecular analysis of neuroblastoma orthotopic PDXs, which revealed strong intrinsic genetic, transcriptional, and phenotypic stability for more than 2 years. The PDXs showed preserved neuroblastoma-associated gene signatures that correlated with poor clinical outcome in a large cohort of patients with neuroblastoma. Furthermore, we captured spatial intratumor heterogeneity using ten PDXs from a single high-risk patient tumor. We observed diverse growth rates, transcriptional, proteomic, and phosphoproteomic profiles. PDX-derived transcriptional profiles were associated with diverse clinical characteristics in patients with high-risk neuroblastoma. These data suggest that high-risk neuroblastoma contains elements of both temporal stability and spatial intratumor heterogeneity, the latter of which complicates clinical translation of personalized PDX-Avatar studies into preclinical cancer research. Significance: These findings underpin the complexity of PDX modeling as a means to advance translational applications against neuroblastoma. (C) 2018 AACR.
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| 2. |
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| 3. |
- Adem, C, et al.
(författare)
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ETV6 rearrangements in patients with infantile fibrosarcomas and congenital mesoblastic nephromas by fluorescence in situ hybridization
- 2001
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Ingår i: Modern Pathology. - : Elsevier BV. - 1530-0285 .- 0893-3952. ; 14:12, s. 1246-1251
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Tidskriftsartikel (refereegranskat)abstract
- Congenital mesoblastic nephroma (CMN) and infantile fibrosarcoma (IFS) are two pediatric tumors arising in the kidneys and soft tissues of infants, respectively. Recently, a t(12;15)(p13;q25) resulting in ETV6-NTRK3 gene fusion was detected in patients with IFS and in patients with the cellular type of CMN, suggesting a common pathogenetic pathway. We investigated the presence or absence of ETV6 rearrangements and numerical abnormalities of chromosome 11 by using fluorescence in situ hybridization on paraffin-embedded material from five cases of IFS, two of CMN, and one of mixed type (CMN and IFS) found in our files. In three cases of IFS, we found ETV6 gene rearrangement but a normal copy number of chromosome 11. One case each of IFS, the cellular type of CMN, and the mixed type (CMN and IFS) had both abnormalities. In a case of classic CMN, neither trisomy 11 nor gene rearrangement was found. It is possible that trisomy 11 is a later, nonessential event in the pathogenetic process or that this secondary aberration is associated with still-unrecognized clinical or biological characteristics. We confirmed that IFS and the cellular type of CMN are cytogenetically related and can occur synchronously in the same organ.
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| 4. |
- Gisselsson, D, et al.
(författare)
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A case of dermatofibrosarcoma protuberans with a ring chromosome 5 and a rearranged chromosome 22 containing amplified COL1A1 and PDGFB sequences
- 1998
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Ingår i: Cancer Letters. - 0304-3835 .- 1872-7980. ; 133:2, s. 34-129
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Tidskriftsartikel (refereegranskat)abstract
- Dermatofibrosarcoma protuberans (DFSP) is a cutaneous tumour of borderline malignancy, the cytogenetic features of which include the translocation t(17;22)(q22;q13) or, more commonly, supernumerary ring chromosomes containing material from 17q22 and 22q13. These rearrangements result in the COL1A1/PDGFB fusion gene. Here, we describe a case of DFSP displaying a ring chromosome 5 together with a large marker chromosome composed of chromosome 22 alphoid DNA, material from distal 12q and amplified COL1A1 and PDGFB sequences. This is the first case of DFSP with multiple copies of COL1A1 and PDGFB not confined to ring chromosomes, showing that DFSP is similar to other borderline malignant mesenchymal tumours, where rings and giant markers are alternative vehicles for amplified material.
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| 5. |
- Gisselsson, D, et al.
(författare)
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Abnormal nuclear shape in solid tumors reflects mitotic instability
- 2001
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Ingår i: American Journal of Pathology. - 1525-2191. ; 158:1, s. 199-206
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Tidskriftsartikel (refereegranskat)abstract
- Abnormalities in nuclear morphology are frequently observed in malignant tissues but the mechanisms behind these phenomena are still poorly understood. In this study, the relation between abnormal nuclear shape and chromosomal instability was explored in short-term tumor cell cultures. Mitotically unstable ring and dicentric chromosomes were identified by fluorescence in situ hybridization at metaphase and subsequently localized in interphase nuclei from five malignant soft tissue tumors. The vast majority (71 to 86%) of nuclear blebs, chromatin strings, and micronuclei contained material from the unstable chromosomes, whereas few (<11%) were positive for stable chromosomes. Nuclear morphology was also evaluated in fibroblasts and an osteosarcoma cell line exposed to irradiation. A linear correlation was found between the frequency of abnormalities in nuclear shape, on one hand, and cells with unstable chromosomes (r = 0.87) and anaphase bridge configurations (r = 0.98), on the other hand. The relation between nuclear shape and karyotypic pattern was investigated further in cultures from 58 tumors of bone, soft tissue, and epithelium. Blebs, strings, and micronuclei were significantly more frequent in tumors that contained rings, dicentrics, or telomeric associations than in those exhibiting only stable aberrations (P: < 0.001) and a positive correlation (r = 0.78) was found between the frequency of such nuclear abnormalities and the intratumor heterogeneity of structural chromosome aberrations. These results indicate that the formation of nuclear blebs, chromatin strings, and micronuclei in malignant tissues is closely related to the breakage-fusion-bridge type of mitotic disturbances. Abnormalities in nuclear shape may thus primarily be regarded as an indicator of genetic instability and intratumor heterogeneity, independent of cytogenetic complexity and the grade of malignancy.
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| 6. |
- Gisselsson, D, et al.
(författare)
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Amplification of 12q13 and 12q15 sequences in a sclerosing epithelioid fibrosarcoma
- 1998
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Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 107:2, s. 102-106
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Tidskriftsartikel (refereegranskat)abstract
- Sclerosing epithelioid fibrosarcoma (SEF) is a recently described entity. It is a low-grade sarcoma that occurs primarily in the deep soft tissues of the extremities of adults. It may histologically simulate benign lesions such as fibroma and myxoma or malignancies such as sclerosing carcinoma and lymphoma, extraskeletal myxoid chondrosarcoma, clear cell sarcoma of tendons and aponeuroses, and synovial sarcoma, depending on the lesion's cellularity, degree of fibrosis, and amount of myxoid matrix. There are no previously published cytogenetic studies of this tumor. We found the karyotype 40-45,XY,add(9)(p13),add(10)(p11),-12,-13,-18,add(18)(q11),add(20)(q11) in a SEF of a 14-year-old boy, by using chromosome banding. Fluorescence in situ hybridization showed that both the add(10) and the add(18) contained amplified sequences from 12q13 and 12q15, including the HMGIC gene. Chromosome 18 material was present in the add(9) and terminally in the add(10). The karyotype of this case indicates that SEF is unrelated to extraskeletal myxoid chondrosarcoma, clear cell sarcoma, and synovial sarcoma. When compared with the findings in other soft tissue tumors such as well-differentiated liposarcoma and low-grade malignant fibrous histiocytoma, the chromosome banding and in situ hybridization data add support to the notion that SEF is a relatively low grade variant of fibrosarcoma.
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| 7. |
- Gisselsson, D, et al.
(författare)
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Centrosomal abnormalities, multipolar mitoses, and chromosomal instability in head and neck tumours with dysfunctional telomeres.
- 2002
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 87:2, s. 202-207
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Tidskriftsartikel (refereegranskat)abstract
- Carcinomas of the head and neck typically exhibit complex chromosome aberrations but the underlying mutational mechanisms remain obscure. Evaluation of cell division dynamics in low-passage cell lines from three benign and five malignant head and neck tumours revealed a strong positive correlation between multipolarity of the mitotic spindle and the formation of bridges at anaphase in both benign and malignant tumours. Cells exhibiting a high rate of mitotic abnormalities also showed several chromosome termini lacking TTAGGG repeats and a high frequency of dicentric chromosomes. Multicolour karyotyping demonstrated a preferential involvement in structural rearrangements of chromosomes with deficient telomeres. The majority of malignant, mitotically unstable tumours expressed the reverse transcriptase subunit of telomerase. These data indicate that some of the genomic instability in head and neck tumours is initiated by telomere dysfunction, leading to the formation of dicentric chromosomes. These form chromosome bridges at mitosis that could prevent the normal anaphase-telophase transition. In turn, this may cause an accumulation of centrosomes and mitotic multipolarity. Telomerase expression does not confer total stability to the tumour genome but could be crucial for moderating the rate of chromosomal evolution.
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| 8. |
- Gisselsson, D, et al.
(författare)
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Chromosomal organization of amplified chromosome 12 sequences in mesenchymal tumors detected by fluorescence in situ hybridization
- 1998
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Ingår i: Genes, Chromosomes and Cancer. - 1045-2257. ; 23:3, s. 203-212
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Tidskriftsartikel (refereegranskat)abstract
- The chromosomal organization of amplified chromosome 12 sequences was studied with fluorescence in situ hybridization in six mesenchymal tumors: two osteosarcomas, one lipoma, two liposarcomas, and one fibrosarcoma. All except the fibrosarcoma contained ring and/or giant marker chromosomes. Amplification of chromosome 12 sequences, demonstrated with whole-chromosome paint in all cases, was confined to ring and giant marker chromosomes in four tumors. In one of the osteosarcomas and in the fibrosarcoma, amplified sequences were added to chromosome 12 and to chromosomes 10, 12, 18, and the Y chromosome, respectively. Hybridizations with single-copy probes demonstrated considerable inter- and intracellular variation in the arrangement of chromosome 12 sequences in ring and marker chromosomes. Amplification of 12q13-15 sequences, predominantly from the HMGIC-MDM2 region, was detected in all cases, but the two osteosarcomas also contained amplification of 12p material. This finding, combined with results from previous studies, indicates that 12p amplification is a feature distinguishing osteosarcomas from adipose tissue tumors. A novel finding was the presence of positive signals for chromosome 12 alpha-satellite sequences in ring and marker chromosomes in four cases. Rod chromosomes carrying amplified material, in particular those that were relatively stable, frequently exhibited chromosome 12 negative terminal segments; two of these, present in two separate cases, were shown by C-banding to contain constitutive heterochromatin. The significant intercellular heterogeneity in the number and structure of rings and giant markers in a subset of mesenchymal tumors could be explained by continuous recombination through breakage-fusion-bridge cycles. If so, this process will continue until broken ends become stabilized, for example by acquisition of telomeric segments from other chromosomes.
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| 9. |
- Gisselsson Nord, David, et al.
(författare)
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Interphase chromosomal abnormalities and mitotic missegregation of hypomethylated sequences in ICF syndrome cells
- 2005
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Ingår i: Chromosoma. - : Springer Science and Business Media LLC. - 0009-5915 .- 1432-0886. ; 114:2, s. 118-126
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Tidskriftsartikel (refereegranskat)abstract
- The immunodeficiency, centromeric region instability, facial anomalies (ICF) syndrome is a rare autosomal recessive disease. Usually, it is caused by mutations in the DNA methyltransferase 3B gene, which result in decreased methylation of satellite DNA in the juxtacentromeric heterochromatin at 1qh, 16qh, and 9qh. Satellite II-rich 1qh and 16qh display high frequencies of abnormalities in mitogen-stimulated ICF lymphocytes without these cells being prone to aneuploidy. Here we show that in lymphoblastoid cell lines from four ICF patients, there was increased colocalization of the hypomethylated 1qh and 16qh sequences in interphase, abnormal looping of pericentromeric DNA sequences at metaphase, formation of bridges at anaphase, chromosome 1 and 16 fragmentation at the telophase-interphase transition, and, in apoptotic cells, micronuclei with overrepresentation of chromosome 1 and 16 material. Another source of anaphase bridging in the ICF cells was random telomeric associations between chromosomes. Our results elucidate the mechanism of formation of ICF chromosome anomalies and suggest that 1qh-16qh associations in interphase can lead to disturbances of mitotic segregation, resulting in micronucleus formation and sometimes apoptosis. This can help explain why specific types of 1qh and 16qh rearrangements are not present at high frequencies in ICF lymphoid cells despite diverse 1qh and 16qh aberrations continuously being generated.
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| 10. |
- Gürtl-Lackner, B., et al.
(författare)
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Solide Kindertumoren : Ein Streifzug durch das Raritätenkabinett
- 2017
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Ingår i: Der Pathologe. - : Springer Science and Business Media LLC. - 0172-8113 .- 1432-1963. ; 38:4, s. 278-285
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Tidskriftsartikel (refereegranskat)abstract
- Solid tumors in childhood are extremely rare entities, which are usually treated in specialized centers. Diagnosis and therapy are carried out according to a joint European protocol, whereby the pathological evaluation and therapy are carried out according to international guidelines. For the correct diagnosis and/or therapy of most tumors, analysis of specific genetic changes is mandatory; therefore, tumors have to be adequately sampled for parallel genetic analysis during the pathological work-up. A second opinion reference of the histopathological assessment is part of the international guidelines. Neuroblastomas, congenital mesoblastic nephromas and rhabdoid tumors are examples of solid tumors in childhood that are not restricted to one organ and occur exclusively during childhood.
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| 11. |
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| 12. |
- Perotti, Daniela, et al.
(författare)
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Hallmark discoveries in the biology of Wilms tumour
- 2023
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Ingår i: Nature Reviews Urology. - 1759-4812.
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Forskningsöversikt (refereegranskat)abstract
- The modern study of Wilms tumour was prompted nearly 50 years ago, when Alfred Knudson proposed the ‘two-hit’ model of tumour development. Since then, the efforts of researchers worldwide have substantially expanded our knowledge of Wilms tumour biology, including major advances in genetics — from cloning the first Wilms tumour gene to high-throughput studies that have revealed the genetic landscape of this tumour. These discoveries improve understanding of the embryonal origin of Wilms tumour, familial occurrences and associated syndromic conditions. Many efforts have been made to find and clinically apply prognostic biomarkers to Wilms tumour, for which outcomes are generally favourable, but treatment of some affected individuals remains challenging. Challenges are also posed by the intratumoural heterogeneity of biomarkers. Furthermore, preclinical models of Wilms tumour, from cell lines to organoid cultures, have evolved. Despite these many achievements, much still remains to be discovered: further molecular understanding of relapse in Wilms tumour and of the multiple origins of bilateral Wilms tumour are two examples of areas under active investigation. International collaboration, especially when large tumour series are required to obtain robust data, will help to answer some of the remaining unresolved questions.
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| 13. |
- Petersén, Åsa, et al.
(författare)
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Euploidy in somatic cells from R6/2 transgenic Huntington's disease mice
- 2005
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Ingår i: BMC Cell Biology. - : Springer Science and Business Media LLC. - 1471-2121. ; 6:34
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Tidskriftsartikel (refereegranskat)abstract
- Background: Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by a CAG repeat expansion in the HD gene. The huntingtin protein expressed from HD has an unknown function but is suggested to interact with proteins involved in the cell division machinery. The R6/2 transgenic mouse is the most widely used model to study HD. In R6/2 fibroblast cultures, a reduced mitotic index and high frequencies of multiple centrosomes and aneuploid cells have recently been reported. Aneuploidy is normally a feature closely connected to neoplastic disease. To further explore this unexpected aspect of HD, we studied cultures derived from 6- and 12-week- old R6/2 fibroblasts, skeletal muscle cells, and liver cells. Results: Cytogenetic analyses revealed a high frequency of polyploid cells in cultures from both R6/2 and wild-type mice with the greatest proportions of polyploid cells in cultures derived from skeletal muscle cells of both genotypes. The presence of polyploid cells in skeletal muscle in vivo was confirmed by fluorescence in situ hybridisation with centromeric probes. Enlarged and supernumerary centrosomes were found in cultures from both R6/ 2 and wild-type mice. However, no aneuploid cells could be found in any of the tissues. Conclusion: We conclude that polyploid cells are found in fibroblast and skeletal muscle cultures derived from R6/2 and wild-type littermate mice and that aneuploidy is unlikely to be a hallmark of HD.
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| 14. |
- Snape, Katie, et al.
(författare)
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Mutations in CEP57 cause mosaic variegated aneuploidy syndrome
- 2011
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 43:6, s. 527-529
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Tidskriftsartikel (refereegranskat)abstract
- Using exome sequencing and a variant prioritization strategy that focuses on loss-of-function variants, we identified biallelic, loss-of-function CEP57 mutations as a cause of constitutional mosaic aneuploidies. CEP57 is a centrosomal protein and is involved in nucleating and stabilizing microtubules. Our findings indicate that these and/or additional functions of CEP57 are crucial for maintaining correct chromosomal number during cell division.
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| 15. |
- Williams, Richard D, et al.
(författare)
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Multiple mechanisms of MYCN dysregulation in Wilms tumour.
- 2015
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Ingår i: Oncotarget. - 1949-2553. ; 6:9, s. 7232-7243
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Tidskriftsartikel (refereegranskat)abstract
- Genomic gain of the proto-oncogene transcription factor gene MYCN is associated with poor prognosis in several childhood cancers. Here we present a comprehensive copy number analysis of MYCN in Wilms tumour (WT), demonstrating that gain of this gene is associated with anaplasia and with poorer relapse-free and overall survival, independent of histology. Using whole exome and gene-specific sequencing, together with methylation and expression profiling, we show that MYCN is targeted by other mechanisms, including a recurrent somatic mutation, P44L, and specific DNA hypomethylation events associated with MYCN overexpression in tumours with high risk histologies. We describe parallel evolution of genomic copy number gain and point mutation of MYCN in the contralateral tumours of a remarkable bilateral case in which independent contralateral mutations of TP53 also evolve over time. We report a second bilateral case in which MYCN gain is a germline aberration. Our results suggest a significant role for MYCN dysregulation in the molecular biology of Wilms tumour. We conclude that MYCN gain is prognostically significant, and suggest that the novel P44L somatic variant is likely to be an activating mutation.
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| 16. |
- Zaigham, Mehreen, et al.
(författare)
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Clinical-pathological features in placentas of pregnancies with SARS-CoV-2 infection and adverse outcome: case series with and without congenital transmission
- 2022
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Ingår i: BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY. - : Wiley. - 1470-0328 .- 1471-0528. ; 129:8, s. 1361-1374
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Tidskriftsartikel (refereegranskat)abstract
- Objective To correlate clinical outcomes to pathology in SARS-CoV-2 infected placentas in stillborn and live-born infants presenting with fetal distress. Design Retrospective, observational. Setting Nationwide. Population Five stillborn and nine live-born infants from 13 pregnant women infected with SARS-CoV-2 seeking care at seven different maternity units in Sweden. Methods Clinical outcomes and placental pathology were studied in 14 cases (one twin pregnancy) of maternal SARS-CoV-2 infection with impaired fetal outcome. Outcomes were correlated to placental pathology in order to investigate the impact of virus-related pathology on the villous capillary endothelium, trophoblast and other cells. Main outcome measures Maternal and fetal clinical outcomes and placental pathology in stillborn and live-born infants. Results Reduced fetal movements were reported (77%) and time from onset of maternal COVID-19 symptoms to signs of fetal distress among live-born infants was 6 (3-12) days and to diagnosis of stillbirth 11 (2-25) days. Two of the live-born infants died during the postnatal period. Signs of fetal distress led to emergency caesarean section in all live-born infants with umbilical cord blood gases and low Apgar scores confirming intrauterine hypoxia. Five stillborn and one live-born neonate had confirmed congenital transmission. Massive perivillous fibrinoid deposition, intervillositis and trophoblast necrosis were associated with SARS-CoV-2 placental infection and congenital transmission. Conclusions SARS-CoV-2 can cause rapid placental dysfunction with subsequent acute fetal hypoxia leading to intrauterine fetal compromise. Associated placental pathology included massive perivillous fibrinoid deposition, intervillositis and trophoblast degeneration.
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