Nikos Papadogiannakis

Hepatocellular carcinoma in ten children under five years of age with bile salt export pump deficiency

Hepatocellular carcinoma (HCC) is rare in young children. We attempted to see if immunohistochemical and mutational‐analysis studies could demonstrate that deficiency of the canalicular bile acid transporter bile salt export pump (BSEP) and mutation in ABCB11, encoding BSEP, underlay progressive familial intrahepatic cholestasis (PFIC)—or “neonatal hepatitis” suggesting PFIC—that was associated with HCC in young children. We studied 11 cases of pediatric HCC in the setting of PFIC or “neonatal hepatitis” suggesting PFIC. Archival liver were retrieved and immunostained for BSEP. Mutational analysis of ABCB11 was performed in leukocyte DNA from available patients and parents. Among the 11 nonrelated children studied aged 13‐52 months at diagnosis of HCC, 9 (and a full sibling, with neonatal hepatitis suggesting PFIC, of a tenth from whom liver was not available) had immunohistochemical evidence of BSEP deficiency; the eleventh child did not. Mutations in ABCB11 were demonstrated in all patients with BSEP deficiency in whom leukocyte DNA could be studied (n = 7). These mutations were confirmed in the parents (n = 14). With respect to the other 3 children with BSEP deficiency, mutations in ABCB11 were demonstrated in all 5 parents in whom leukocyte DNA could be studied. Thirteen different mutations were found. In conclusion, PFIC associated with BSEP deficiency represents a previously unrecognized risk for HCC in young children. Immunohistochemical evidence of BSEP deficiency correlates well with demonstrable mutation in ABCB11. (HEPATOLOGY 2006;44:478–486.)

Frequency of human parvovirus B19 infection in intrauterine fetal death

BACKGROUND Parvovirus B19 is known to cause fetal death in the second trimester, mainly in combination with hydrops fetalis. However, the frequency of parvovirus-B19-associated non-hydropic fetal loss in the late second and third trimester has not been thoroughly investigated. We aimed to investigate the frequency of parvovirus B19 infection in unselected cases of intrauterine fetal death and to assess the sensitivity of different diagnostic procedures. METHODS Of 14147 deliveries in three hospitals in the major Stockholm area of Sweden, all cases of intrauterine fetal death (>22 gestational weeks) that occurred between January, 1998, and May, 1999 (n=47), referred cases of miscarriage (<22 gestational weeks, n=37), and induced abortions (n=29), were included in the study. Placental and fetal tissues were examined by means of parvovirus-B19-specific PCR, histopathology, and immunohistochemistry. Placental tissues from 53 normal pregnancies at term were also examined. FINDINGS Significantly more cases of intrauterine fetal death were positive for parvovirus B19 DNA (seven [15%]) than were normal pregnancies at term (zero, p=0.049). Furthermore, parvovirus B19 DNA was found in two (5%) of the miscarriages but not in any of the cases of induced abortion. Only three of nine DNA-positive cases had parvovirus-B19-associated inclusions and stained positive for viral proteins. All but one of the DNA-positive cases of intrauterine fetal death were non-hydropic. INTERPRETATION The presence of parvovirus B19 DNA in cases of late second-trimester and third-trimester fetal death is common, and most are non-hydropic. The sensitivity of conventional diagnostic procedures for intrauterine fetal death could be greatly improved by addition of parvovirus B19 PCR.

Parvovirus B19 infection: association with third‐trimester intrauterine fetal death

Objective To identify the presence of parvovirus B19 infection as a possible cause of fetal loss in the third trimester.

On the origin of trisomy 21 Down syndrome

BackgroundDown syndrome, characterized by an extra chromosome 21 is the most common genetic cause for congenital malformations and learning disability. It is well known that the extra chromosome 21 most often originates from the mother, the incidence increases with maternal age, there may be aberrant maternal chromosome 21 recombination and there is a higher recurrence in young women. In spite of intensive efforts to understand the underlying reason(s) for these characteristics, the origin still remains unknown. We hypothesize that maternal trisomy 21 ovarian mosaicism might provide the major causative factor.ResultsWe used fluorescence in situ hybridization (FISH) with two chromosome 21-specific probes to determine the copy number of chromosome 21 in ovarian cells from eight female foetuses at gestational age 14–22 weeks. All eight phenotypically normal female foetuses were found to be mosaics, containing ovarian cells with an extra chromosome 21. Trisomy 21 occurred with about the same frequency in cells that had entered meiosis as in pre-meiotic and ovarian mesenchymal stroma cells.ConclusionWe suggest that most normal female foetuses are trisomy 21 ovarian mosaics and the maternal age effect is caused by differential selection of these cells during foetal and postnatal development until ovulation. The exceptional occurrence of high-grade ovarian mosaicism may explain why some women have a child with Down syndrome already at young age as well as the associated increased incidence at subsequent conceptions. We also propose that our findings may explain the aberrant maternal recombination patterns previously found by family linkage analysis.

Mechanism of Accumulation of Cholesterol and Cholestanol in Tendons and the Role of Sterol 27-hydroxylase (CYP27A1)

Objective—Tendon xanthomas are deposits of lipids and connective tissue commonly found in hypercholesterolemic patients. Macrophages are likely to be responsible for the lipid accumulation. Normolipidemic patients with the rare disease cerebrotendinous xanthomatosis, lacking the enzyme sterol 27-hydroxylase (CYP27A1), develop prominent xanthomas in tendons and brain containing both cholestanol and cholesterol, with a cholestanol:cholesterol ratio higher than that in the circulation. Because of its ability to convert cholesterol into polar metabolites that leave the cells faster, CYP27A1 has been suggested to be an antiatherogenic enzyme. The hypothesis was tested that tendons contain CYP27A1 that may be of importance for the normal efflux of both steroids. Methods and Results—Western blotting and combined gas chromatography-mass spectrometry showed that human tendons contain significant amounts of CYP27A1 and its product, 27-hydroxycholesterol. Immunohistochemistry showed that CYP27A1 is present in macrophages and tenocytes. The tendons also contained cholestanol, with a cholestanol:cholesterol ratio slightly higher than that in the circulation. Recombinant human CYP27A1, and cultured human macrophages containing this enzyme, had similar activity toward cholesterol and cholestanol. After loading of macrophages with labeled cholesterol and cholestanol, there was an efflux of these steroids in both unmetabolized and 27-oxygenated form, resulting in a significant cellular accumulation of cholestanol compared with cholesterol. Conclusion—The results are consistent with the possibility that CYP27A1 is of importance for the efflux of both cholesterol and cholestanol from tendons.

Association studies on 11 published colorectal cancer risk loci

Background:Recently, several genome-wide association studies (GWAS) have independently found numerous loci at which common single-nucleotide polymorphisms (SNPs) modestly influence the risk of developing colorectal cancer. The aim of this study was to test 11 loci, reported to be associated with an increased or decreased risk of colorectal cancer: 8q23.3 (rs16892766), 8q24.21 (rs6983267), 9p24 (rs719725), 10p14 (rs10795668), 11q23.1 (rs3802842), 14q22.2 (rs4444235), 15q13.3 (rs4779584), 16q22.1 (rs9929218), 18q21.1 (rs4939827), 19q13.1 (rs10411210) and 20p12.3 (rs961253), in a Swedish-based cohort.Methods:The cohort was composed of 1786 cases and 1749 controls that were genotyped and analysed statistically. Genotype–phenotype analysis, for all 11 SNPs and sex, age of onset, family history of CRC and tumour location, was performed.Results:Of eleven loci, 5 showed statistically significant odds ratios similar to previously published findings: 8q23.3, 8q24.21, 10p14, 15q13.3 and 18q21.1. The remaining loci 11q23.1, 16q22.1, 19q13.1 and 20p12.3 showed weak trends but somehow similar to what was previously published. The loci 9p24 and 14q22.2 could not be confirmed. We show a higher number of risk alleles in affected individuals compared to controls. Four statistically significant genotype–phenotype associations were found; the G allele of rs6983267 was associated to older age, the G allele of rs1075668 was associated with a younger age and sporadic cases, and the T allele of rs10411210 was associated with younger age.Conclusions:Our study, using a Swedish population, supports most genetic variants published in GWAS. More studies are needed to validate the genotype–phenotype correlations.

A Radiographic and Histologic Evaluation of the Patellar Tendon after Harvesting Its Central Third

Nineteen consecutive patients undergoing anterior cruciate ligament reconstruction using the central third of the ipsilateral patellar tendon were included in the study. Serial magnetic resonance images revealed that the donor-site gap in the tendon decreased with time (mean follow-up, 26 months). The thickness was significantly increased compared with the intact contralateral patellar tendon, regardless of when the magnetic resonance imaging was performed. Ultrasonography showed the same findings at a mean follow-up of 26 months. Histologic evaluation of the repair tissue in the central part of the tendon, as well as the tissue in the peripheral part of the patellar tendon at the donor site, revealed a significant increase in cellularity and vascularity as compared with normal control tendons. Thus, 2 years after the harvesting procedure, the patellar tendon displayed significant radiographic and histologic abnormalities. On the basis of these findings, reharvest of the patellar tendon, at least up to 2 years after primary harvest, cannot be recommended.

The Stockholm classification of stillbirth

Objective. To design and validate a classification system for audit groups working with stillbirth. The classification includes well‐defined primary and associated conditions related to fetal death. Design. Descriptive. Setting. All delivery wards in Stockholm. Population. Stillbirths from 22 completed weeks in Stockholm, Sweden. Methods. Parallel to audit work, the Stockholm stillbirth group has developed a classification of conditions related to stillbirth. The classification has been validated. Main outcome measure. The classification and the results of the validation are presented. Result. The classification with 17 groups identifying underlying conditions related to stillbirth (primary diagnoses) and associated factors which may have contributed to the death (associated diagnoses) is described. The conditions are subdivided into definite, probable and possible relation to the death. An evaluation of 382 cases of stillbirth during 2002–2005 resulted in 382 primary diagnoses and 132 associated diagnoses. The most common conditions identified were intrauterine growth restriction/placental insufficiency (23%), infection (19%), malformations/chromosomal abnormalities (12%). The ‘unexplained’ group together with the ‘unknown’ group comprised 18%. Validation was done by reclassification of 95 cases from 2005 by six investigators. The overall agreement regarding primary diagnosis was substantial (kappa=0.70). Conclusions. The Stockholm classification of stillbirth consists of 17 diagnostic groups allowing one primary diagnosis and if needed, associated diagnoses. Diagnoses are subdivided according to definite, probable and possible relation to stillbirth. Validation showed high degree of agreement regarding primary diagnosis. The classification can provide a useful tool for clinicians and audit groups when discussing cause and underlying conditions of fetal death.

Fetal intracranial haemorrhages caused by fetal and neonatal alloimmune thrombocytopenia: an observational cohort study of 43 cases from an international multicentre registry

Objective To characterise pregnancies where the fetus or neonate was diagnosed with fetal and neonatal alloimmune thrombocytopenia (FNAIT) and suffered from intracranial haemorrhage (ICH), with special focus on time of bleeding onset. Design Observational cohort study of all recorded cases of ICH caused by FNAIT from the international No IntraCranial Haemorrhage (NOICH) registry during the period 2001–2010. Setting 13 tertiary referral centres from nine countries across the world. Participants 37 mothers and 43 children of FNAIT pregnancies complicated by fetal or neonatal ICH identified from the NOICH registry was included if FNAIT diagnosis and ICH was confirmed. Primary and secondary outcome measures Gestational age at onset of ICH, type of ICH and clinical outcome of ICH were the primary outcome measures. General maternal and neonatal characteristics of pregnancies complicated by fetal/neonatal ICH were secondary outcome measures. Results From a total of 592 FNAIT cases in the registry, 43 confirmed cases of ICH due to FNAIT were included in the study. The majority of bleedings (23/43, 54%) occurred before 28 gestational weeks and often affected the first born child (27/43, 63%). One-third (35%) of the children died within 4 days after delivery. 23 (53%) children survived with severe neurological disabilities and only 5 (12%) were alive and well at time of discharge. Antenatal treatment was not given in most (91%) cases of fetal/neonatal ICH. Conclusions ICH caused by FNAIT often occurs during second trimester and the clinical outcome is poor. In order to prevent ICH caused by FNAIT, at-risk pregnancies must be identified and prevention and/or interventions should start early in the second trimester.

Maternal microchimerism in human fetal tissues.

OBJECTIVE The aim of the present study was to analyze the presence of maternal cells in human fetal tissues in the second trimester. STUDY DESIGN Tissues from 11 second-trimester fetuses terminated because of social reasons or because of malformations and/or trisomy were investigated. By cell sorting and polymerase chain reaction amplification, we studied the presence of maternal CD3+, CD19+, CD34+, and CD45+ in different fetal tissues and in placenta. RESULTS In the group of fetuses with normal karyotype and normal autopsy findings, 4 of 5 fetuses were positive for maternal microchimerism. In the group in which the fetuses were diagnosed with trisomy 21 and/or malformations, we found cells of maternal origin in 3 of 6 fetuses. CONCLUSION The results from this study indicate that maternal microchimerism is a common phenomenon in the second-trimester fetuses. Maternal cells of lymphoid and myeloid lineages and hematopoietic progenitors are widely distributed in the second-trimester fetuses.