Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

Abstract 3124: Prognostic biomarkers for pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has the lowest 5-year-survival rate of common cancers (< 7%), but despite intensive research efforts over the past several decades, its dismal prognosis has barely improved. Recent genome-wide association studies (GWAS) have linked several genetic factors with pancreatic cancer, but there is generally poor overlap in the results from such studies, presumably due to population heterogeneity. In this study, we collected previously published pancreatic risk loci from multiple GWAS studies, and correlated these loci with clinical information gathered on a well-characterized cohort of 148 PDAC patients from the University Health Network in Toronto Canada, and several other North American hospitals, which have undergone whole-genome sequencing. Using this cohort, we attempted to identify prognostic genomic biomarkers by correlating the germline genomic alterations observed in our cohort to overall survival (OS). By understanding the mechanism of germline variants that alter OS, we hope to develop insights that will lead to improved detection and therapy for PDAC patients.

Among the 67 published risk loci we tested using a multivariate Cox proportional hazard model, we found a strong positive association of the single nucleotide polymorphism rs4785367 (RefSNP alleles: C/T on forward strand; MAF = 0.474) with overall survival of PDAC donors: HR = 0.426; CI = 0.268 - 0.686; p-value = 0.00029. A more detailed analysis at the genotype level revealed that the presence of the homozygous minor allele has a stronger effect than either the heterozygous or homozygous major allele. The SNP falls within the intergenic region between the ZNF423 and TMEM188 genes, within the exon 2 of lncRNA RP11-305A4.3 and overlaps a CTCF regulatory domain. Preliminary gene expression analysis from RNA sequencing data on a subset of PDAC donors (n = 28) shows that patients carrying the minor allele have significant higher TMEM188 expression than of the major type (p-value = 0.012), suggesting that this allele may influence the course of PDAC via TMEM188 activity. A recent study linked the gene product to activation of NK cells, which in turns increases the defense mechanism against the pathogens, infections and transformed tumors. These findings suggest a possible molecular mechanism influencing the course of PDAC. We are also exploring the effect of the presence of the minor allele on the regulatory CTCF region, by applying an integrative pipeline for risk SNP analysis to pancreatic cancer. This will possibly detect the effect on the NANOG motif binding and/or on CTCF looping.

In summary, the present study detected the rs4785367 as a prognostic biomarker for pancreatic cancer, with the novelty of increased TMEM188 gene expression being linked to the presence of the alternate allele in PDAC patients. Further investigations on this and on assessing the effect of the polymorphism on the regulatory CTCF feature are in progress.

Citation Format: Cristina Baciu, Robert Grant, Hansen He, Musaddeque Ahmed, Robert E. Denroche, Lee Timms, Gun Ho Jang, Ayelet Borgida, Xihui Lin, Paul C. Boutros, Dianne Chadwich, Sheng-Ben Liang, Sagedeh Shahabi, Michael H.A. Roehrl, Sean Cleary, Julie M. Wilson, John D. McPherson, Lincoln Stein, Steven Gallinger. Prognostic biomarkers for pancreatic cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3124.

Sub-lethal doses of photodynamic therapy affect biofilm formation ability and metabolic activity of Enterococcus faecalis

BACKGROUND

During photodynamic therapy (PDT) in the treatment of a primary endodontic infection, it is extremely likely that microorganisms would be exposed to sub-lethal doses of PDT (sPDT). Although sPDT cannot kill microorganisms, it can considerably influence microbial virulence. This study was conducted to characterize the effect of sPDT using toluidine blue O (TBO), methylene blue (MB), and indocyanine green (ICG) on biofilm formation ability and metabolic activity of Enterococcus faecalis.

METHODS

The antimetabolic and antibiofilm potential of ICG-, TBO-, and MB-sPDT against E. faecalis was analyzed at sub-lethal doses (1/2-1/64 minimum inhibitory concentration) using the XTT reduction assay, crystal violet assay, and scanning electron microscopy.

RESULTS

Higher doses of sPDT adversely affected biofilm formation ability and metabolic activity. ICG-, TBO-, and MB-PDT at a maximum sub-lethal dose markedly reduced the formation of biofilm up to 42.8%, 22.6%, and 19.5%, respectively. ICG-, TBO-, and MB-sPDT showed a marked reduction in bacterial metabolic activity by 98%, 94%, and 82%, respectively. ICG-PDT showed a stronger inhibitory effect on biofilm formation in E. faecalis than MB- and TBO-PDT at sub-lethal levels. Interestingly, a gradual increase in metabolic activity and biofilm formation upon exposure to a lower dose of test sPDT were observed.

CONCLUSION

sPDT showed dual effect on biofilm formation ability and metabolic activity of E. faecalis. High doses revealed antimetabolic and antibiofilm potential activity, whereas lower doses had conflicting results. Hence, when PDT is prescribed in clinical settings, the dose of PDT used in vivo should be taken into consideration.

Evaluation of antimicrobial photodynamic therapy with indocyanine green and curcumin on human gingival fibroblast cells: An in vitro photocytotoxicity investigation

Recent investigations have suggested that antimicrobial photodynamic therapy (aPDT) can be an alternative treatment for the management of periodontal infections. However, currently there is very limited data regarding the photocytotoxicity of this method on human gingival fibroblast (HuGu) cells.

AIM

The in vitro optimal concentrations of indocyanine green (ICG) and curcumin as photosensitizers (PSs) and the irradiation time of diode laser emission were evaluated by assessing the photocytotoxicity of the treatment on HuGu cells.

MATERIALS AND METHOD

Monolayers of HuGu cells were incubated with various final concentrations of ICG (500, 750, 1000, 1250, 1500, 1750, and 2000μg/ml) and curcumin (3, 4, 5, 10, and 20mM). Three exposure times of the diode laser (30s, 60s, and 2×30s irradiation with an interval of 1min between each) and one of exposure time of 5min for LED were tested; cell viability was determined using neutral red assay. Chlorhexidine (CHX) as a gold standard antimicrobial agent for periodontal disease was considered as a control group.

RESULTS

ICG and curcumin significantly reduced HuGu cell viability at concentrations below 1000μg/ml and 10mM, respectively (P<0.01). Cytotoxicity was higher when the cells were treated for 2×30s irradiation with an interval of 1min and then again exposed to the laser for 30s (2% and 0.1%). CHX demonstrated no significant reduction in HuGu cell survival.

CONCLUSION

Photocytotoxicity is influenced by PS concentration, exposure time of PS, and time of irradiation. High doses of ICG and curcumin with lowest exposure time of light source and without cytotoxic effects may be an effective strategy for aPDT as an alternative treatment for periodontal disease.

The effect of low level laser therapy on pain reduction after third molar surgery

AIM

The aim of this study was to evaluate the effects of low level laser on the postoperative pain of patients who had to undergo third molar surgery.

METHODS

In a randomized clinical setting, 100 patients were assigned to two groups of 50 in each. Every patient underwent surgical removal of one mandibular third molar (with osteotomy). After suturing the flap, the soft laser was applied to every patient. In group I laser radiation was applied by the dental assistant with output power of 100 mW, in continuous mode with sweeping motion, in group II, the laser hand piece was only brought into position without releasing energy, so that no patient knew which group he belonged to. The patient was given a pain evaluation form where they could determine their individual pain level and duration.

RESULTS

The statistical tests showed significant difference in pain level between laser and control group (P<0.001) but no significant difference found in pain duration in two groups (P=0.019).

CONCLUSION

The result of this study verifies the positive effect of the soft-laser therapy in the postoperative complication after third molar extraction.

Class III β-tubulin (TUBB3): more than a biomarker in solid tumors?

Class III β-tubulin (TUBB3) is a prominent mechanism of drug resistance expressed in a variety of solid tumors and particularly in lung and ovarian cancer. In the classical view, TUBB3 expression and drug resistance have been linked, and together they have been associated with a perturbation in microtubule dynamics. In keeping with this observation, TUBB3 was associated with drug resistance only when chemotherapy included a taxane in its chemical composition. In this review, we demonstrate that the classical supposition about TUBB3 is not correct, and that instead TUBB3 expression is linked to drug resistance as a complex survival mechanism activated by microenvironmental conditions such as poor nutrient supply and hypoxia.

Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method

OBJECTIVE

One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.

MATERIALS AND METHODS

Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.

RESULTS

The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05).

CONCLUSION

Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.

Effect of Ramadan fasting on serum heat shock protein 70 and serum lipid profile

INTRODUCTION

Ramadan, the holy month for the Islamic world, is a period every year when food and fluid intake is restricted to the pre-sunrise and post-sunset hours. The aim of this study was to evaluate the effect of Ramadan fasting on the serum concentration of heat shock protein 70 (HSP70) and serum lipid profile in healthy men.

METHODS

A total of 32 male volunteers with a mean age of 28.5 (range 23-37) years were selected for the study. Blood samples were obtained one day prior to Ramadan and on the 3rd and 25th days of fasting. Serum HSP70, triglyceride (TG), cholesterol (Chol), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), LDL/HDL and Chol/HDL ratios were investigated.

RESULTS

It was observed that the mean concentrations of serum HSP70 and HDL on the 25th day of Ramadan were significantly higher than those recorded one day before Ramadan and on the 3rd day of Ramadan, and the levels on the 3rd day of Ramadan was significantly higher than those recorded one day before Ramadan. Mean concentrations of serum TG, Chol, LDL, and LDL/HDL and Chol/HDL ratios on the 25th day of Ramadan were significantly lower than those recorded one day before Ramadan and on the 3rd day of Ramadan, and the levels found on the 3rd day of Ramadan were also significantly lower than those recorded one day before Ramadan.

CONCLUSION

Ramadan fasting increases serum HSP70 and improves serum lipid profile.

Gp96 rich lysate as a vaccine candidate against infection with Salmonella typhimurium

BACKGROUND AND OBJECTIVES

Glycoprotein 96 is the primary chaperone of the endoplasmic reticulum. Immunization with it induced potent Cytotoxic T lymphocyte responses to intracellular bacteria. S. typhimurium is a facultative intracellular bacterium and acquired resistance against this bacterium mainly depends on activity of Cytotoxic T cells. This study aimed to evaluate the capacity of Glycoprotein 96 rich lysate as a vaccine candidate to induce a protective immune response in mice against a lethal dose challenge with Salmonella typhimurium.

MATERIALS AND METHODS

Mice were infected with S. typhimurium. Then their spleens and livers were harvested and homogenized and the protein content of whole crude lysate was enriched using ammonium sulfate precipitation. SDS-polyacrylamide gel electrophoresis transfer method was used for enrichment of the protein from crude sample. Immunoblotting was conducted to detect Glycoprotein 96. Isoelectric point was achieved through the use of isoelectric focusing. PBS and whole crude lysate (from uninfected and infected mice) were injected to mice of test group, mice of control-1 group and mice of control-2 group, respectively, on days 0 and 14. Twenty-one days after the last immunization, the LD50 and bacterial loads of livers and spleens were determined.

RESULTS AND CONCLUSION

Immunization with Glycoprotein 96 rich lysate isolated from livers and spleens of S. typhimuriuminfected mice induced protection against infection by S. typhimurium. Also, the bacterial burden of livers and spleens in mice that received gp96 rich lysate significantly decreased when compared to that of mice in the control groups.

The relevance of rising CA-125 levels within the normal range in predicting recurrence in patients with advanced stage ovarian cancer: A validation study

e16521

Background: Small published series suggested that three progressively rising CA-125 values, doubling of CA-125, and an absolute rise of 5 U/mL from the nadir, all while remaining in the normal range were highly associated with disease recurrence. This study aims to validate these proposed criteria in a larger population. Methods: We conducted a retrospective review of the records of patients with stages IIIC and IV epithelial ovarian cancer treated with primary surgery and adjuvant chemotherapy between 1994 and 2006. Only patients who had a complete response to chemotherapy verified by normal CT scan, CA-125 and physical examination were included. Nadir CA-125 level was defined as the first CA-125 measurement after completing chemotherapy. Available CA-125 values from diagnosis to recurrence or to last follow up were collected and evaluated for meeting any of the criteria above. Results: 91 patients with a median age of 59 (42 - 88) met the inclusion criteria. 82 patients had stage IIIC (90%) and 9 patients (10%) had stage IV. 86 patients (94.5%) had papillary serous histology and 88 patients had grade 3 (96.7%) disease. Median follow up was 43.7 months (12.6 - 156). Table 1 shows the number of patients who met any of the above CA-125 criteria in total and divided by the presence or absence of recurrence. There was no statistically significant difference in meeting any of the CA-125 criteria between the recurrence and no recurrence groups. Meeting at least one of the CA-125 criteria had 50% sensitivity, 65% specificity, and 86% positive predictive value for recurrence. The median time to recurrence in patients who met at least one CA-125 criteria was 3.8 months (0.2 - 12.4) and the median follow up time after meeting one of the CA 125 criteria in patients who did not recur was 88.5 months (10.4 - 188) Conclusions: Rising CA-125 levels within the normal range that meet any of the above criteria are highly predictive (86%) of recurrence within 12 months and closer observation is warranted. [Table: see text]

No significant financial relationships to disclose.

Immune response to measles vaccine after mass vaccination in Urmia, Islamic Republic of Iran

We investigated the effectiveness of the mass measles vaccination campaign in Urmia, Islamic Republic of Iran, by examining the measles IgG seroprevalence and antibody response from paired data before and after the campaign. The overall seropositive rate of 624 subjects aged 5-25 years increased 1 year after the mass vaccination (from 53.0% to 72.3%). A rise in antibody titre occurred in all age groups except the 21-25 years group, which had the highest titre before mass vaccination. On logistic regression analysis, only immune status prior to vaccination was significantly associated with the seroresponse. It may be cost-effective to check antibody titres before mass vaccinations, especially in high vaccine coverage regions with circulating wild virus.

The role of hyperglycosylated hCG in trophoblast invasion and the prediction of subsequent pre-eclampsia

OBJECTIVE

Hyperglycosylated hCG (HhCG) is the predominant form of chorionic gonadotrophin in states characterized by aggressive trophoblast invasion such as early pregnancy or choriocarcinoma. Pre-eclampsia may be the result of failed or inadequate trophoblast invasion. We investigated whether low levels of maternal urine HhCG levels would predict subsequent pre-eclampsia.

STUDY DESIGN

Mid-trimester urine (14-21 weeks) was collected and frozen from non-hypertensive women undergoing genetic amniocentesis. Inclusion criteria were: normal singleton pregnancies without a prior history of pre-eclampsia, hypertension, diabetes or other vascular disorders. The specimens were subsequently thawed, and HhCG levels standardized to urine creatinine were measured. Maternal charts were reviewed after delivery to determine the development of pre-eclampsia. There were a total of 568 study subjects.

RESULTS

Pre-eclampsia developed in 26 (4.6%) women. There was a significant correlation between low urine HhCG and subsequent pre-eclampsia (Mantel-Haenszel test of linear association: Chi-square 10.52, p=0.001). The mean HhCG level (ng/mg creatinine) was significantly greater in normals than in those destined to develop pre-eclampsia: 42.7 versus 20.3, p=0.002 (Mann-Whitney U-test). There was a progressive increase in the risk of subsequent pre-eclampsia as HhCG levels fell: HhCG < or =0.9 MoM RR (95% CI)=1.51 (1.15-1.98) compared with < or =0.1 MoM 10.42 (2.0-54.3).

CONCLUSION

Low maternal mid-trimester urine HhCG predicted subsequent pre-eclampsia. This appears to support the view that pre-eclampsia results at least in part from poor trophoblast invasion. Thus, HhCG may play a role in trophoblast invasion and measurement of this in urine identifies women at high risk for developing pre-eclampsia.

Management of a ruptured basilar artery aneurysm during pregnancy

A 36 year old woman who ruptured a basilar artery aneurysm at 38 weeks gestation in her second pregnancy was managed successfully by endovascular embolisation 36 hours after an emergency Caesarean section. The timing of treatment along with the obstetric, neurosurgical and anaesthetic aspects of this complex problem are discussed along with a review of the current literature on the subject.

Utility of commonly used commercial human chorionic gonadotropin immunoassays in the diagnosis and management of trophoblastic diseases

BACKGROUND

Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the beta-subunit C-terminal segment, hyperglycosylated hCG, and free beta subunit) that are recognized to differing extents by automated immunometric hCG (or hCG beta) assays. This has led to low or false-negative results and misdiagnosis of persistent disease. False-positive hCG immunoreactivity has also been detected, leading to needless therapy for trophoblastic diseases. Here we compare seven commonly used hCG assays.

METHODS

Standards for five irregular forms hCG produced in trophoblastic diseases, serum samples from 59 patients with confirmed trophoblastic diseases, and serum samples from 12 women with previous false-positive hCG results (primarily in the Abbott AxSYM assay) were blindly tested by commercial laboratories in the Beckman Access hCG beta, the Abbott AxSYM hCG beta, the Chiron ACS:180 hCG beta, the Baxter Stratus hCG test, the DPC Immulite hCG test, the Serono MAIAclone hCG beta tests, and in the hCG beta RIA.

RESULTS

Only the RIA and the DPC appropriately detected the five irregular hCG standards. Only the Beckman, DPC, and Abbott assays gave results similar to the RIA in the patients with confirmed trophoblastic diseases (values within 25% of RIA in 49, 49, and 54 of 59 patients, respectively). For samples that were previously found to produce false-positive hCG results, no false-positive results were detected with the DPC and Chiron tests (5 samples, median <2 IU/L), but up to one-third of samples were false positive (>10 IU/L) in the Beckman (1 of 5), Serono (2 of 9), and Baxter assays (1 of 5), and the hCG beta RIA (3 of 9; median for all assays, <5 IU/L). These samples, which produced false-positive results earlier in the Abbott AxSYM assay, continued to produce high values upon reassessment (median, 81 IU/L).

CONCLUSIONS

Of six frequently used hCG immunometric assays, only the DPC detected the five irregular forms of beta hCG, agreed with the RIA, and avoided false-positive results in the samples tested. This assay, and similarly designed assays not tested here, seem appropriate for hCG testing in the diagnosis and management of trophoblastic diseases.

The role of laparoscopy in the diagnosis and treatment of peritoneal carcinomatosis: a case report

A patient presented with deep venous thrombosis and an elevated CA-125 level, but normal pelvic ultrasound and abdominal and pelvic CT scans. Laparoscopy revealed diffuse carcinomatosis and a diagnosis of stage IIIc, poorly differentiated epithelial ovarian carcinoma was made. Laparoscopy may provide an alternative means of diagnosis when conventional imaging fails, and may facilitate the placement of catheters for subsequent intraperitoneal therapy.

The role of chemotherapy and prophylactic bilateral oophorectomy in a case of colorectal adenocarcinoma with ovarian metastases

A 66-year-old female presented with a large abdominal mass and accompanying systemic complaints of abdominal pain, constipation. and fever. On exploratory laparotomy, the mass was found to be a moderately differentiated adenocarcinoma of the sigmoid colon with metastasis to the left ovary. A primary colorectal carcinoma that has metastasized to the ovaries can be difficult to distinguish clinically from an advanced primary ovarian tumor. Histology and tumor markers are currently the most useful tools available in making an accurate diagnosis. If the nature of the primary tumor is uncertain and the initial response to chemotherapy is poor, the patient's prognosis will also he poor. Though controversy exists regarding the role of prophylactic bilateral oophorectomy during resection for primary colorectal cancer, later confusion can be avoided by performing this procedure when the colorectal carcinoma is first diagnosed. However the possibility of a concurrent primary ovarian tumor must not be overlooked.

Comparison of urinary hyperglycosylated human chorionic gonadotropin concentration with the serum triple screen for Down syndrome detection in high-risk pregnancies

OBJECTIVE

Both modest screening performance and declining patient and physician acceptance have stimulated interest in alternative markers to the triple screen for the detection of Down syndrome. Our purpose was to compare the concentration of a single urinary analyte, hyperglycosylated human chorionic gonadotropin, with the serum triple screen (alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol concentrations combined with age) for second-trimester Down syndrome detection.

STUDY DESIGN

Urine and blood were obtained from pregnant women in the second trimester undergoing genetic amniocentesis. Urinary hyperglycosylated human chorionic gonadotropin concentration and serum triple-screen values were measured. Individuals undergoing amniocentesis because of abnormal triple-screen results were excluded. Individual Down syndrome risks on the basis of urinary hyperglycosylated human chorionic gonadotropin concentration plus maternal age and on the basis of the triple-screen results were calculated. For each algorithm the sensitivity and false-positive rate for Down syndrome detection at different risk thresholds were determined. From these values receiver operating characteristic curves were constructed, and the area under the curve was determined for each algorithm. Finally, the performance of a new combination in which urinary hyperglycosylated human chorionic gonadotropin concentration replaced serum human chorionic gonadotropin concentration in the triple screen was ascertained.

RESULTS

We studied 24 pregnancies complicated by Down syndrome and 500 unaffected pregnancies between 14 and 22 weeks' gestation in a mostly white (93.5%) population undergoing amniocentesis primarily because of advanced maternal age. The sensitivity and false-positive rate for urinary hyperglycosylated human chorionic gonadotropin concentration were 75. 0% and 5.6%, respectively, whereas those for the triple screen were 75.0% and 33.2%, respectively. Urinary hyperglycosylated human chorionic gonadotropin concentration was superior to the triple screen (area under the curve, 0.9337 vs 0.7887; P =.02). The substitution of urinary hyperglycosylated human chorionic gonadotropin concentration for serum human chorionic gonadotropin concentration in the triple screen resulted in a 91.7% sensitivity at a 10.0% false-positive rate, versus a 54.2% sensitivity for the traditional triple screen at the same false-positive rate.

CONCLUSION

The performance of urinary hyperglycosylated human chorionic gonadotropin concentration was statistically superior to that of the serum triple screen in a high-risk population. The use of urinary hyperglycosylated human chorionic gonadotropin concentration as an alternative test or substitution of this measurement for serum human chorionic gonadotropin concentration in the triple screen would improve diagnostic accuracy and address many current concerns related to the triple screen.

Spontaneous rupture of a splenic artery aneurysm in pregnancy: report of two cases

The spontaneous rupture of a splenic artery aneurysm during pregnancy is a rare but catastrophic event. Two cases are reported, both involving fetal death and one maternal death as well. A review of the literature covering this condition shows that mortality amongst pregnant women remains high at 75% with 95% fetal loss, which compares with a 25% mortality rate amongst non-pregnant women. Clinical presentation is often non-specific, with good haemodynamic compensation, followed by a rapid deterioration. The best investigation appears to be a diagnostic laparotomy. The discussion stresses the importance of early diagnosis faced with this serious condition, as well as the potential benefits of a prompt lower mid-line incision in terms of statistical survival for both mother and fetus.

Urine hyperglycosylated hCG plus ultrasound biometry for detection of down syndrome in the second trimester in a high-risk population

OBJECTIVE

To evaluate measurement of levels of urine hyperglycosylated hCG, a form of hCG with abnormally branched oligosaccharide side chains, in conjunction with ultrasound biometry for Down syndrome risk prediction in an at-risk group.

METHOD

We prospectively measured urine hyperglycosylated hCG levels, humeral length, and nuchal thickness in women who had second-trimester amniocentesis. Urine hyperglycosylated hCG levels were measured by a two-step enzyme-immunometric assay using monoclonal antibody beta152. Humeral length, nuchal thickness, and hyperglycosylated hCG values were expressed as multiples of the median, and the Down syndrome screening efficiency of the three analytes plus age was determined. A receiver operating characteristic (ROC) curve was generated, and the area under the curve was used to assess the Down syndrome screening performance of the algorithm.

RESULTS

There were 23 cases of Down syndrome among 1016 singleton pregnancies. Mean gestational age (+/- standard deviation) was 16.1 +/- 1.2 weeks at the time of amniocentesis. Mean maternal age was 37.1 +/- 3.2 years. Biometry and measurement of hyperglycosylated hCG levels had a 91.3% detection rate at a 3.2% false-positive rate and a 100% detection rate at a 10.7% false-positive rate. The area under the ROC curve was 0.986 (P <.001), and that for measurement of hyperglycosylated hCG levels plus age was 0.941 (P <.001). The area under the curve was significantly larger with combined biochemical and biometry markers compared with measurement of hyperglycosylated hCG levels plus age alone (P <.02), proving that the former was superior to the latter.

CONCLUSION

A new Down syndrome biochemical marker combined with ultrasound biometry had a high screening efficiency in a high-risk group. All cases of Down syndrome in this study population would have been detected at an amniocentesis rate of less than 10.7%. Our results appear superior to those found with other second-trimester algorithms. The combination is promising as an alternative to "automatic" genetic amniocentesis in women of advanced maternal age and other high-risk groups.

Hyperglycosylated human chorionic gonadotropin (invasive trophoblast antigen) immunoassay: A new basis for gestational Down syndrome screening

BACKGROUND

Serum human chorionic gonadotropin (hCG) and hCG free beta-subunit tests are used in combination with unconjugated estriol and alpha-fetoprotein in the triple screen test, and with the addition of inhibin-A in the quadruple marker test for detecting Down syndrome in the second trimester of pregnancy. These tests have a limited detection rate for Down syndrome: approximately 40% for hCG or free beta-subunit alone, approximately 60% for the triple screen test, and approximately 70% for the quadruple marker test, all at 5%, or a relatively high, false-positive rate. New tests are needed with higher detection and lower false rates. Hyperglycosylated hCG (also known as invasive trophoblast antigen or ITA) is a new test. It specifically detects a unique oligosaccharide variant of hCG associated with Down syndrome pregnancies. We evaluated this new Down syndrome-directed test in prenatal diagnosis.

METHODS

Hyperglycosylated hCG was measured in urine samples from women undergoing amniocentesis for advanced maternal age concerns at 14-22 weeks of gestation, 1448 with normal karyotype and 39 with Down syndrome fetuses.

RESULTS

The median hyperglycosylated hCG value was 9.5-fold higher in Down syndrome cases (9.5 multiples of the normal karyotype median). The single test detected 80% of Down syndrome cases at a 5% false-positive rate. Urine hyperglycosylated hCG was combined with urine beta-core fragment (urine breakdown product of serum hCG free beta-subunit), serum alpha-fetoprotein, and maternal age-related risk. This urine-serum combination detected 96% of Down syndrome cases at a 5% false-positive rate, 94% of cases at a 3% false-positive rate, and 71% of cases at a 1% false-positive rate. These detection rates exceed those of any previously reported combination of biochemical markers.

CONCLUSIONS

Hyperglycosylated hCG is a new base marker for Down syndrome screening in the second trimester of pregnancy. The measurement of hyperglycosylated hCG can fundamentally improve the performance of Down syndrome screening protocols.

Maternal urine hyperglycosylated hCG in pregnancies with Down syndrome

Stored maternal urine samples were used to determine the distribution of hyperglycosylated human chorionic gonadotrophin (H-hCG) levels in pregnancies with Down syndrome. A total of 349 samples from singleton pregnancies, including 45 with Down syndrome, were tested at 10-19 weeks' gestation. Urinary concentration was allowed for by expressing H-hCG in ng per mmol creatinine. The median level in Down syndrome was 3.63 multiples of the gestation-specific median in unaffected pregnancies (p<0.0001, Wilcoxon rank-sum test, two-tail). However, creatinine levels were relatively low in cases and creatinine did not fully correct for concentration. When this bias was allowed for, the median level was 3.34 multiples of the normal median (MoM). The H-hCG elevation in affected pregnancies was more marked at 14 weeks' gestation or later: a median of 4.64 MoM and allowing for creatinine bias 4.46 MoM.