Leiden Cytology and Pathology Laboratory

Leiden, Netherlands

Leiden Cytology and Pathology Laboratory

Leiden, Netherlands
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Smit P.W.,Leiden Cytology and Pathology Laboratory | Elliott I.,Leiden Cytology and Pathology Laboratory | Elliott I.,University of Nottingham | Peeling R.W.,Leiden Cytology and Pathology Laboratory | And 5 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2014

Tropical infectious diseases diagnosis and surveillance are often hampered by difficulties of sample collection and transportation. Filter paper potentially provides a useful medium to help overcome such problems. We reviewed the literature on the use of filter paper, focusing on the evaluation of nucleic acid and serological assays for diagnosis of infectious diseases using dried blood spots (DBS) compared with recognized gold standards. We reviewed 296 eligible studies and included 101 studies evaluating DBS and 192 studies on other aspects of filter paper use. We also discuss the use of filter paper with other body fluids and for tropical veterinary medicine. In general, DBS perform with sensitivities and specificities similar or only slightly inferior to gold standard sample types. However, important problems were revealed with the uncritical use of DBS, inappropriate statistical analysis, and lack of standardized methodology. DBS have great potential to empower healthcare workers by making laboratory-based diagnostic tests more readily accessible, but additional and more rigorous research is needed. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.


Gao L.,Leiden University | Van Den Hurk K.,Maastricht University | Moerkerk P.T.M.,Leiden University | Goeman J.J.,Leiden Cytology and Pathology Laboratory | And 6 more authors.
Journal of Investigative Dermatology | Year: 2014

Dysplastic nevi are melanocytic lesions that represent an intermediate stage between common nevus and melanoma. Histopathological distinction of dysplastic nevus from melanoma can be challenging and there is a requirement for molecular diagnostic markers. In this study, we examined promoter CpG island methylation of a selected panel of genes, identified in a genome-wide methylation screen, across a spectrum of 405 melanocytic neoplasms. Promoter methylation analysis in common nevi, dysplastic nevi, primary melanomas, and metastatic melanomas demonstrated progressive epigenetic deregulation. Dysplastic nevi were affected by promoter methylation of genes that are frequently methylated in melanoma but not in common nevi. We assessed the diagnostic value of the methylation status of five genes in distinguishing primary melanoma from dysplastic nevus. In particular, CLDN11 promoter methylation was specific for melanoma, as it occurred in 50% of primary melanomas but in only 3% of dysplastic nevi. A diagnostic algorithm that incorporates methylation of the CLDN11, CDH11, PPP1R3C, MAPK13, and GNMT genes was validated in an independent sample set and helped distinguish melanoma from dysplastic nevus (area under the curve 0.81). Melanoma-specific methylation of these genes supports the utility as epigenetic biomarkers and could point to their significance in melanoma development. © 2014 The Society for Investigative Dermatology.


Dols J.A.M.,Rotterdam University | Smit P.W.,Leiden Cytology and Pathology Laboratory | Kort R.,Applied Scientific Research | Reid G.,University of Western Ontario | And 5 more authors.
American Journal of Obstetrics and Gynecology | Year: 2011

Objective: The objective was to examine the use of a tailor-made DNA microarray containing probes representing the vaginal microbiota to examine bacterial vaginosis. Study Design: One hundred one women attending a health center for HIV testing in South Africa were enrolled. Stained, liquid-based cytology slides were scored for bacterial vaginosis. An inventory of organisms was obtained using microarray technology, probing genera associated with bacterial vaginosis in more detail, namely Gardnerella, Atopobium, Dialister, Leptotrichia, Megasphaera, Mobiluncus, Peptostreptococcus, Prevotella, and Sneathia. Results: Of 101 women, 34 were diagnosed positive for bacterial vaginosis. This condition was associated with an increased microbial diversity. It is no longer useful to base the diagnosis of bacterial vaginosis on Gardnerella alone. Rather, its presence with Leptotrichia and Prevotella species, and especially Atopobium was more indicative of an aberrant state of the vaginal flora. Conclusion: To understand the vaginal microbiota in more detail, microarray-based identification can be used after microscopic scoring. © 2011 Mosby, Inc. All rights reserved.


PubMed | Leiden Cytology and Pathology Laboratory, Lawson Health Research Institute, Applied Scientific Research, VU University Amsterdam and 2 more.
Type: | Journal: BMC infectious diseases | Year: 2016

To date, women are most often diagnosed with bacterial vaginosis (BV) using microscopy based Nugent scoring or Amsel criteria. However, the accuracy is less than optimal. The aim of the present study was to confirm the identity of known BV-associated composition profiles and evaluate indicators for BV using three molecular methods.Evaluation of indicators for BV was carried out by 16S rRNA amplicon sequencing of the V5-V7 region, a tailor-made 16S rRNA oligonucleotide-based microarray, and a PCR-based profiling technique termed IS-profiling, which is based on fragment variability of the 16S-23S rRNA intergenic spacer region. An inventory of vaginal bacterial species was obtained from 40 females attending a Dutch sexually transmitted infection outpatient clinic, of which 20 diagnosed with BV (Nugent score 7-10), and 20 BV negative (Nugent score 0-3).Analysis of the bacterial communities by 16S rRNA amplicon sequencing revealed two clusters in the BV negative women, dominated by either Lactobacillus iners or Lactobacillus crispatus and three distinct clusters in the BV positive women. In the former, there was a virtually complete, negative correlation between L. crispatus and L. iners. BV positive subjects showed cluster profiles that were relatively high in bacterial species diversity and dominated by anaerobic species, including Gardnerella vaginalis, and those belonging to the Families of Lachnospiraceae and Leptotrichiaceae. Accordingly, the Gini-Simpson index of species diversity, and the relative abundance Lactobacillus species appeared consistent indicators for BV. Under the conditions used, only the 16S rRNA amplicon sequencing method was suitable to assess species diversity, while all three molecular composition profiling methods were able to indicate Lactobacillus abundance in the vaginal microbiota.An affordable and simple molecular test showing a depletion of the genus Lactobacillus in combination with an increased species diversity of vaginal microbiota could serve as an alternative and practical diagnostic method for the assessment of BV.


Hrushesky W.J.M.,University of South Carolina | Sothern R.B.,University of Minnesota | Du-Quiton J.,University of South Carolina | Quiton D.F.T.,University of South Carolina | And 2 more authors.
Astrobiology | Year: 2011

Periodic episodes of increased sunspot activity (solar electromagnetic storms) occur with 10-11 and 5-6 year periodicities and may be associated with measurable biological events. We investigated whether this sunspot periodicity characterized the incidence of Pap smear-determined cervical epithelial histopathologies and human physiologic functions. From January 1983 through December 2003, monthly averages were obtained for solar flux and sunspot numbers; six infectious, premalignant and malignant changes in the cervical epithelium from 1,182,421 consecutive, serially independent, screening Pap smears (59°9″N, 4°29″E); and six human physiologic functions of a healthy man (oral temperature, pulse, systolic and diastolic blood pressure, respiration, and peak expiratory flow), which were measured ∼5 times daily during ∼34,500 self-measurement sessions (44°56″N, 93°8″W). After determining that sunspot numbers and solar flux, which were not annually rhythmic, occurred with a prominent 10-year and a less-prominent 5.75-year periodicity during this 21-year study span, each biological data set was analyzed with the same curve-fitting procedures. All six annually rhythmic Pap smear-detected infectious, premalignant and malignant cervical epithelial pathologies showed strong 10-year and weaker 5.75-year cycles, as did all six self-measured, annually rhythmic, physiologic functions. The phases (maxima) for the six histopathologic findings and five of six physiologic measurements were very near, or within, the first two quarters following the 10-year solar maxima. These findings add to the growing evidence that solar magnetic storm periodicities are mirrored by cyclic phase-locked rhythms of similar period length or lengths in human physiology and pathophysiology. © Mary Ann Liebert, Inc.


Roeters A.M.E.,Leiden Cytology and Pathology Laboratory | Boon M.E.,Leiden Cytology and Pathology Laboratory | Van Haaften M.,Diakonessenhuis | Vernooij F.,University Utrecht | And 2 more authors.
Diagnostic Cytopathology | Year: 2010

The Dutch cytological coding system, KOPAC, enables to code for eight inflammatory events, that is koilocytosis (related to human papillomavirus (HPV)), Trichomonas, dysbacteriosis [related to bacterial vaginosis (BV)], Candida, Gardnerella, Actinomyces, Chlamydia, and non-specific inflammation (leucocytosis). This study presents an analysis of 1,008,879 smears. Of each smear, the age of the woman and the reason for smear taking (screening or indication) was available. The cytoscores (per mille) for these codes were calculated. For the screening smears, the cytoscores were for koilocytosis (HPV) 2.6, for Trichomonas vaginalis 1.9, for dysbacteriosis 31.4, for Candida albicans 9.8, for Gardnerella vaginalis 0.7, for Actinomyces 6.9, for Chlamydia 0.8, and for non-specific inflammatory changes 66.4. For the calculation of the Odds Ratio (OR), normal smears were used as a reference. The cytoscores for Chlamydia and Gardnerella covaried with high grade SIL (HSIL), with an OR of 7 and 12, respectively. In addition, the OR for Trichomonas vaginalis, for dysbacteriosis, and for leucocytosis proved to be significantly high in the indication smears. This study provides an oversight of HSIL and the full range of cervical infections as detected by cytology, proving that this infectious byproduct of screening can be very valuable. © 2009 Wiley-Liss, Inc.


Gao L.,Leiden University | Smit M.A.,Netherlands Cancer Institute | van den Oord J.J.,Catholic University of Leuven | Goeman J.J.,Leiden University | And 9 more authors.
Pigment Cell and Melanoma Research | Year: 2013

The involvement of epigenetic alterations in the pathogenesis of melanoma is increasingly recognized. Here, we performed genome-wide DNA methylation analysis of primary cutaneous melanoma and benign melanocytic nevus interrogating 14 495 genes using BeadChip technology. This genome-wide view of promoter methylation in primary cutaneous melanoma revealed an array of recurrent DNA methylation alterations with potential diagnostic applications. Among 106 frequently hypermethylated genes, there were many novel methylation targets and tumor suppressor genes. Highly recurrent methylation of the HOXA9, MAPK13, CDH11, PLEKHG6, PPP1R3C, and CLDN11 genes was established. Promoter methylation of MAPK13, encoding p38δ, was present in 67% of primary and 85% of metastatic melanomas. Restoration of MAPK13 expression in melanoma cells exhibiting epigenetic silencing of this gene reduced proliferation, indicative of tumor suppressive functions. This study demonstrates that DNA methylation alterations are widespread in melanoma and suggests that epigenetic silencing of MAPK13 contributes to melanoma progression. © 2013 John Wiley & Sons A/S.


Risse E.K.J.,Leiden Cytology and Pathology Laboratory | Ouwerkerk-Noordam E.,Leiden Cytology and Pathology Laboratory | Boon M.E.,Leiden Cytology and Pathology Laboratory
Acta Cytologica | Year: 2011

Objective: It was our aim to assess the usefulness of cytohistology in cervical thin layer brush samples with problems in the differential diagnosis of endometrial cells. Study Design: This study reveals the cytological, cytohistological and immunohistochemistry findings of 8 cases suspicious of adenocarcinoma in situ (AIS)/adenocarcinoma (AC) in cervical liquid-based cytology (LBC) preparations that turned out to be normal endometrial cells. Results: All 8 cervical LBCs featured endometrial and atypical endocervical-like columnar cells with frequent ragged 'feathered' edge appearance and rosette formations. Overlapping atypical glandular cell groups were present on 2 ThinPrep slides as well. In cytohistology of 7 cases, the recognition of endometrial stroma with endometrial glands easily allowed the diagnosis of normal endometrium. In 1 case with very small loose tissue fragments without glands, the diagnosis could be established by positivity for CD10 marker (endometrial stroma) and without proliferative activity in the Ki-67 immunostaining. Conclusion: In cervical LBC preparations, nuclear hyperchromasia, pleomorphism and nucleoli in normal endometrial cells are more obvious than in conventional smears, and their arrangement is sometimes suggestive of AIS or AC. In the 8 cases presented, we could avoid a false-positive diagnosis of AIS or AC through cytohistology/ immunohistochemistry, and in consequence, unnecessary colposcopical/histological examination. Copyright © 2011 S. Karger AG, Basel.


Benschop C.C.G.,Netherlands Forensic Institute | Quaak F.C.A.,Netherlands Forensic Institute | Boon M.E.,Leiden Cytology and Pathology Laboratory | Sijen T.,Netherlands Forensic Institute | Kuiper I.,Netherlands Forensic Institute
International Journal of Legal Medicine | Year: 2012

Forensic analysis of biological traces generally encompasses the investigation of both the person who contributed to the trace and the body site(s) from which the trace originates. For instance, for sexual assault cases, it can be beneficial to distinguish vaginal samples from skin or saliva samples. In this study, we explored the use of microbial flora to indicate vaginal origin. First, we explored the vaginal microbiome for a large set of clinical vaginal samples (n0240) by next generation sequencing (n0338,184 sequence reads) and found 1,619 different sequences. Next, we selected 389 candidate probes targeting genera or species and designed a microarray, with which we analysed a diverse set of samples; 43 DNA extracts from vaginal samples and 25 DNA extracts from samples from other body sites, including sites in close proximity of or in contact with the vagina. Finally, we used the microarray results and next generation sequencing dataset to assess the potential for a future approach that uses microbial markers to indicate vaginal origin. Since no candidate genera/species were found to positively identify all vaginal DNA extracts on their own, while excluding all non-vaginal DNA extracts, we deduce that a reliable statement about the cellular origin of a biological trace should be based on the detection of multiple species within various genera. Microarray analysis of a sample will then render a microbial flora pattern that is probably best analysed in a probabilistic approach. © Springer-Verlag 2011.


Risse E.K.J.,Leiden Cytology and Pathology Laboratory | Ouwerkerk-Noordam E.,Leiden Cytology and Pathology Laboratory | Meijer-Marres E.M.,Leiden Cytology and Pathology Laboratory | Boon M.E.,Leiden Cytology and Pathology Laboratory
Acta Cytologica | Year: 2010

Objective: To exploit cervical thin layer brush samples through cytohistology in cases with invasive carcinoma with application of antibodies. Study Design: Fourteen cases from women with carcinoma diagnosed in 2006 were selected out of 29 invasive carcinomas. From these 14 cases liquid-based cervical cytology material was available to prepare cytohistology. Eight women had squamous cell carcinoma, 4 endocervical adenocarcinoma, 1 endometrial adenocarcinoma and 1 ovarian adenocarcinoma. The residual material from the thin layer sample, collected by brushes by general practitioners, was used to prepare paraffin sections. These were stained with the Papanicolaou method and for the biomarkers Ki-67 and p16 and, if desired, for differentiation markers, including carcinoembryonic antigen, vimentin, cytokeratin 7 and cytokeratin 20 to establish the immunoprofile of the carcinoma. Results: The morphologic details in the cancer nuclei in the paraffin sections were excellent, while in all cases the thin layer cytology slide contained thick epithelial fragments with blurred nuclei. In 5 of the 6 adenocarcinomas, the glandular architecture diagnostic of adenocarcinoma was visible in the cytohistology, which was highlighted in the biomarker stainings, particularly so in the Ki-67 sections. With the exception of endometrial adenocarcinoma, all p16INK4a stainings were positive, as they were in the ovarian adenocarcinoma case. Conclusion: Cytohistology is an adjunct to routine cervical cytologic examination of thin layer samples, allowing an unequivocal and refined diagnosis. © The International Academy of Cytology.

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