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Dive into the research topics where Johanna Ekström is active.

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Featured researches published by Johanna Ekström.


Journal of Clinical Oncology | 2013

Evaluation of Human Papillomavirus Antibodies and Risk of Subsequent Head and Neck Cancer

Aimée R. Kreimer; Mattias Johansson; Tim Waterboer; Rudolf Kaaks; Jenny Chang-Claude; Dagmar Drogen; Anne Tjønneland; Kim Overvad; J. Ramón Quirós; Carlos A. González; Maria José Sánchez; Nerea Larrañaga; Carmen Navarro; Aurelio Barricarte; Ruth C. Travis; Kay-Tee Khaw; Nicholas J. Wareham; Antonia Trichopoulou; Pagona Lagiou; Dimitrios Trichopoulos; Petra H.M. Peeters; Salvatore Panico; Giovanna Masala; Sara Grioni; Rosario Tumino; Paolo Vineis; H. Bas Bueno-de-Mesquita; Göran Laurell; Göran Hallmans; Jonas Manjer

PURPOSE Human papillomavirus type 16 (HPV16) infection is causing an increasing number of oropharyngeal cancers in the United States and Europe. The aim of our study was to investigate whether HPV antibodies are associated with head and neck cancer risk when measured in prediagnostic sera. METHODS We identified 638 participants with incident head and neck cancers (patients; 180 oral cancers, 135 oropharynx cancers, and 247 hypopharynx/larynx cancers) and 300 patients with esophageal cancers as well as 1,599 comparable controls from within the European Prospective Investigation Into Cancer and Nutrition cohort. Prediagnostic plasma samples from patients (collected, on average, 6 years before diagnosis) and control participants were analyzed for antibodies against multiple proteins of HPV16 as well as HPV6, HPV11, HPV18, HPV31, HPV33, HPV45, and HPV52. Odds ratios (ORs) of cancer and 95% CIs were calculated, adjusting for potential confounders. All-cause mortality was evaluated among patients using Cox proportional hazards regression. RESULTS HPV16 E6 seropositivity was present in prediagnostic samples for 34.8% of patients with oropharyngeal cancer and 0.6% of controls (OR, 274; 95% CI, 110 to 681) but was not associated with other cancer sites. The increased risk of oropharyngeal cancer among HPV16 E6 seropositive participants was independent of time between blood collection and diagnosis and was observed more than 10 years before diagnosis. The all-cause mortality ratio among patients with oropharyngeal cancer was 0.30 (95% CI, 0.13 to 0.67), for patients who were HPV16 E6 seropositive compared with seronegative. CONCLUSION HPV16 E6 seropositivity was present more than 10 years before diagnosis of oropharyngeal cancers.


International Journal of Cancer | 2011

High throughput sequencing reveals diversity of human papillomaviruses in cutaneous lesions.

Johanna Ekström; Davit Bzhalava; Daniel Svenback; Ola Forslund; Joakim Dillner

There are at least 120 completely characterized human papillomavirus (HPV) types and putative new types are continuously found. Both squamous cell carcinoma of the skin (SCC) and other skin lesions commonly contain multiple cutaneous HPV types. The objective of this study was to achieve an improved resolution of the diversity of HPV types in lesions such as SCCs, actinic keratoses (AKs) and keratoacanthomas (KAs). Fresh frozen biopsies from 37 SCC lesions, 36 AK lesions and 92 KA lesions and swab samples from the top of the lesion from 86 SCCs and 92 AKs were amplified using the general HPV primers FAP and mixed to three pools followed by high throughput sequencing. We obtained 2196 reads with homology to HPV. In the pool of SCC/AK biopsies 48 different HPV types were found. Eighty‐three types were found in the pool of SCC/AK swab samples and 64 types in the KA biopsies, respectively. For 9 novel putative HPV types most of the amplimer sequence was obtained, whereas for an additional 35 novel putative HPV types only partial amplimer sequences were obtained. Most of the novel putative types belonged to the genus Gamma. In conclusion, high throughput sequencing was an effective means to identify both known and previously unknown HPV types in putatively HPV‐associated lesions and has revealed an extended diversity of HPV types.


Scientific Reports | 2015

Deep sequencing extends the diversity of human papillomaviruses in human skin

Davit Bzhalava; Laila Sara Arroyo Mühr; Camilla Lagheden; Johanna Ekström; Ola Forslund; Joakim Dillner; Emilie Hultin

Most viruses in human skin are known to be human papillomaviruses (HPVs). Previous sequencing of skin samples has identified 273 different cutaneous HPV types, including 47 previously unknown types. In the present study, we wished to extend prior studies using deeper sequencing. This deeper sequencing without prior PCR of a pool of 142 whole genome amplified skin lesions identified 23 known HPV types, 3 novel putative HPV types and 4 non-HPV viruses. The complete sequence was obtained for one of the known putative types and almost the complete sequence was obtained for one of the novel putative types. In addition, sequencing of amplimers from HPV consensus PCR of 326 skin lesions detected 385 different HPV types, including 226 previously unknown putative types. In conclusion, metagenomic deep sequencing of human skin samples identified no less than 396 different HPV types in human skin, out of which 229 putative HPV types were previously unknown.


International Journal of Cancer | 2014

Smoking as a major risk factor for cervical cancer and pre-cancer: Results from the EPIC cohort

Esther Roura; Xavier Castellsagué; Michael Pawlita; Noémie Travier; Tim Waterboer; Núria Margall; F. Xavier Bosch; Silvia de Sanjosé; Joakim Dillner; Inger Torhild Gram; Anne Tjønneland; Christian Munk; Valeria Pala; Domenico Palli; Kay-Tee Khaw; Ruanne V. Barnabas; Kim Overvad; Françoise Clavel-Chapelon; Marie-Christine Boutron-Ruault; Guy Fagherazzi; Rudolf Kaaks; Annekatrin Lukanova; Annika Steffen; Antonia Trichopoulou; Dimitrios Trichopoulos; Eleni Klinaki; Rosario Tumino; Carlotta Sacerdote; Salvatore Panico; H. B. Bueno-de-Mesquita

A total of 308,036 women were selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) study to evaluate the association between tobacco smoking and the risk of cervical intraepithelial neoplasia of grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC). At baseline, participants completed a questionnaire and provided blood samples. During a mean follow‐up time of 9 years, 261 ICC cases and 804 CIN3/CIS cases were reported. In a nested case–control study, the baseline sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11, 16, 18, 31, 33, 35, 45, 52, 58, and antibodies against Chlamydia trachomatis (CT), and Human Herpes Virus 2 (HHV‐2). Cervical samples were not available for HPV‐DNA analysis in this study. Multivariate analyses were used to estimate associations between smoking and risk of CIN3/CIS and ICC in the cohort and the case–control studies. In the cohort analyses smoking status, duration and intensity showed a two‐fold increased risk of CIN3/CIS and ICC, while time since quitting was associated with a two‐fold reduced risk. In the nested case–control study, consistent associations were observed after adjustment for HPV, CT and HHV‐2 serostatus, in both HPV seronegative and seropositive women. Results from this large prospective study confirm the role of tobacco smoking as an important risk factor for both CIN3/CIS and ICC, even after taking into account HPV exposure as determined by HPV serology. The strong beneficial effect of quitting smoking is an important finding that will further support public health policies for smoking cessation.


Sexually Transmitted Diseases | 2013

Human papillomavirus typing in reporting of condyloma.

Erik Sturegård; Hanna K Johansson; Johanna Ekström; Bengt-Göran Hansson; Annika Johnsson; Eva Gustafsson; Joakim Dillner; Ola Forslund

Background Monitoring of condylomas is an early evidence of population effectiveness of human papillomavirus (HPV) vaccination programs. If reporting could include HPV typing, the contribution by vaccine HPV types to condyloma burden could be monitored. Methods A sentinel site for reporting of condyloma including HPV typing was established at the Centre for Sexual Health in Malmö, Sweden. In 2006 to 2009, when there were few HPV vaccines, 621 subjects with condyloma were reported and HPV genotyped. Results Ninety-four percent of the condylomas contained genital HPV types. Thirty-five different genital HPV types were identified, with HPV6 (62%), HPV16 (13%), and HPV11 (10%) being the most common. At least 1 of the 4 HPV types in the HPV6/11/16/18 vaccine was detected in 77%. High-risk HPV types were more common in females (45%) than among males (27%) (odds ratio, 1.9; confidence interval, 1.3–2.8). Extended testing among subjects initially negative for HPV found 21 patients with cutaneous types of HPV, including a novel type (HPV153). Conclusions This report provides a baseline distribution of HPV types in condylomas before the introduction of an HPV vaccination program in this population. Human papillomavirus typing is feasible in routine condyloma reporting.


Virology | 2010

Three novel papillomaviruses (HPV109, HPV112 and HPV114) and their presence in cutaneous and mucosal samples.

Johanna Ekström; Ola Forslund; Joakim Dillner

To expand our knowledge of the genomic diversity of human papillomaviruses (HPVs), we searched for new HPVs in squamous cell carcinomas of the skin (SCC) and seemingly HPV-negative, otherwise typically HPV-associated lesions. We describe the characterization of three novel HPV types. HPV109 was isolated from an SCC, HPV112 from a condyloma and HPV114 from a low-grade cervical lesion. Pairwise alignment of the L1 sequences classified HPV114 to genus alpha species 3, whereas HPV112 defined a new species in the genus gamma. HPV109 had uncertain classification because of a low and about equal similarity in the L1 gene (between 60% and 65%) to different genera. Type-specific real-time PCRs of cervical samples, a majority from women with low grade atypical cytology, (n=2856) and various cutaneous samples (n=538), found HPV114 in 1.7% (48/2856) of the genital samples, whereas both HPV109 and 112 were rare viruses found at high viral loads only in their index samples.


The Journal of Infectious Diseases | 2011

Antibodies to Merkel Cell Polyomavirus Correlate to Presence of Viral DNA in the Skin

Helena Faust; Diana V. Pastrana; Christopher B. Buck; Joakim Dillner; Johanna Ekström

To validate whether Merkel cell polyomavirus (MCV) serology correlates with MCV infection, we compared real-time polymerase chain reaction results for MCV DNA on fresh-frozen biopsy specimens from various skin lesions and healthy skin from 434 patients to MCV serology results using viruslike particles (VLPs) and MCV neutralization assays. Sixty-five percent of participants were MCV seropositive and 18% were MCV DNA positive. The presence of antibodies was correlated with the presence of virus DNA (odds ratio, 27.85 [95% confidence interval, 6.6-166.5]), with 97% of patients who tested positive for MCV DNA being MCV seropositive. VLP antibody levels correlated to neutralization titers (r=.72), and high antibody levels correlated to high MCV load (P<.01).


PLOS ONE | 2013

Unbiased approach for virus detection in skin lesions.

Davit Bzhalava; Hanna K Johansson; Johanna Ekström; Helena Faust; Birgitta Moller; Carina Eklund; Peter Nordin; Bo Stenquist; John Paoli; Bengt Persson; Ola Forslund; Joakim Dillner

To assess presence of virus DNA in skin lesions, swab samples from 82 squamous cell carcinomas of the skin (SCCs), 60 actinic keratoses (AKs), paraffin-embedded biopsies from 28 SCCs and 72 kerathoacanthomas (KAs) and fresh-frozen biopsies from 92 KAs, 85 SCCs and 92 AKs were analyzed by high throughput sequencing (HTS) using 454 or Ion Torrent technology. We found total of 4,284 viral reads, out of which 4,168 were Human Papillomavirus (HPV)-related, belonging to 15 known (HPV8, HPV12, HPV20, HPV36, HPV38, HPV45, HPV57, HPV59, HPV104, HPV105, HPV107, HPV109, HPV124, HPV138, HPV147), four previously described putative (HPV 915 F 06 007 FD1, FA73, FA101, SE42) and two putatively new HPV types (SE46, SE47). SE42 was cloned, sequenced, designated as HPV155 and found to have 76% similarity to the most closely related known HPV type. In conclusion, an unbiased approach for viral DNA detection in skin tumors has found that, although some new putative HPVs were found, known HPV types constituted most of the viral DNA.


International Journal of Cancer | 2015

Human papillomavirus type 197 is commonly present in skin tumors.

L. Sara Arroyo Mühr; Emilie Hultin; Davit Bzhalava; Carina Eklund; Camilla Lagheden; Johanna Ekström; Hanna K Johansson; Ola Forslund; Joakim Dillner

Non‐melanoma skin cancers commonly contain Human Papillomavirus (HPV), but the types found have varied depending on the polymerase chain reaction (PCR) primer systems used. Whole genome amplified DNA (not amplified by any specific PCR primers) from 91 skin lesions [41 squamous cell skin carcinomas (SCCs), 8 keratoacanthomas, 22 actinic keratoses, 3 basal cell carcinomas and 17 SCCs in situ] were sequenced. All samples were sequenced both at 160 Mb and 1.8 Gb sequencing depth per sample. The sequences from 10 different HPVs in 47/91 specimens were found. Sequences represented four established HPV types (HPV types 16, 22, 120, 124), two previously known putative types (present in GenBank) and four previously unknown HPV sequences (new putative types). The most commonly detected virus was cloned, sequenced and designated as HPV197. Type‐specific real‐time PCR detected HPV197 in 34/91 specimens. For comparison, a pool of the same samples after general primer PCR amplification was also sequenced. This revealed 40 different HPVs, but only two HPV types were detected both with sequencing without prior PCR and with sequencing PCR amplicons, suggesting that sequencing without prior PCR gives a more unbiased representation of the HPVs present. In summary, it was found that HPV can be sequenced from most skin disease specimens and HPV197 appeared to be the most commonly present virus.


Cancer Epidemiology, Biomarkers & Prevention | 2015

Human Papillomavirus 16 E6 Antibodies in Individuals without Diagnosed Cancer: A Pooled Analysis

Krystle A. Lang Kuhs; Devasena Anantharaman; Tim Waterboer; Mattias Johansson; Paul Brennan; Angelika Michel; Martina Willhauck-Fleckenstein; Mark P. Purdue; Ivana Holcatova; Wolfgang Ahrens; Pagona Lagiou; Jerry Polesel; Lorenzo Simonato; Franco Merletti; Claire M. Healy; Kristina Kjaerheim; David I. Conway; Tatiana V. Macfarlane; Peter Thomson; Xavier Castellsagué; Ariana Znaor; Amanda Black; Wen Yi Huang; Vittorio Krogh; Antonia Trichopoulou; H. B. Bueno-de-Mesquita; Françoise Clavel-Chapelon; Elisabete Weiderpass; Johanna Ekström; Elio Riboli

Background: The increasing incidence of oropharyngeal cancer in many developed countries has been attributed to human papillomavirus type 16 (HPV16) infections. Recently, HPV16 E6 serology has been identified as a promising early marker for oropharyngeal cancer. Therefore, characterization of HPV16 E6 seropositivity among individuals without cancer is warranted. Methods: A total of 4,666 controls were pooled from several studies of cancer and HPV seropositivity, all tested within the same laboratory. HPV16 E6 seropositive controls were classified as having (i) moderate [mean fluorescent intensity (MFI) ≥ 484 and <1,000] or (ii) high seroreactivity (MFI ≥ 1,000). Associations of moderate and high HPV16 E6 seroreactivity with (i) demographic risk factors; and seropositivity for (ii) other HPV16 proteins (E1, E2, E4, E7, and L1), and (iii) E6 proteins from non-HPV16 types (HPV6, 11, 18, 31, 33, 45, and 52) were evaluated. Results: Thirty-two (0.7%) HPV16 E6 seropositive controls were identified; 17 (0.4%) with moderate and 15 (0.3%) with high seroreactivity. High HPV16 E6 seroreactivity was associated with former smoking [odds ratio (OR), 5.5; 95% confidence interval (CI), 1.2–51.8], and seropositivity against HPV16 L1 (OR, 4.8; 95% CI, 1.3–15.4); E2 (OR, 7.7; 95% CI, 1.4–29.1); multiple HPV16 proteins (OR, 25.3; 95% CI, 2.6–119.6 for three HPV16 proteins beside E6) and HPV33 E6 (OR, 17.7; 95% CI, 1.9–81.8). No associations were observed with moderate HPV16 E6 seroreactivity. Conclusions: High HPV16 E6 seroreactivity is rare among individuals without diagnosed cancer and was not explained by demographic factors. Impact: Some HPV16 E6 seropositive individuals without diagnosed HPV-driven cancer, especially those with seropositivity against other HPV16 proteins, may harbor a biologically relevant HPV16 infection. Cancer Epidemiol Biomarkers Prev; 24(4); 683–9. ©2015 AACR.

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Tim Waterboer

German Cancer Research Center

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Antonia Trichopoulou

National and Kapodistrian University of Athens

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Kay-Tee Khaw

University of Cambridge

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Rosario Tumino

International Agency for Research on Cancer

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