Meriem Khyatti

Dr. Meriem Khyatti


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2014 in European Journal of Public Health
Verified
Journal Article
Open access
PDF file
MKMeriem Khyatti
Meriem Khyatti
RTRoxana-Delia Trimbitas
Roxana-Delia Trimbitas
YZYassine Zouheir
Yassine Zouheir
ABAbdelouaheb Benani
Abdelouaheb Benani
MMMoulay-Driss El Messaoudi
Moulay-Driss El Messaoudi
KHKari Hemminki
Kari Hemminki
The epidemiological transition has reduced infectious diseases mortality in most European countries, yet increased migrant influx risks importing diseases. All reported prevalence rates must be considered on a case-by-case basis depending on the disease in question, respective European Union (EU) country and migratory patterns at work. Tuberculosis has seen a re-emergence in Europe and is concentrated among migrants. Migrants arriving from North Africa (NA) and sub-Saharan Africa (SSA) carry higher rates of hepatitis C and B than the local EU population. The human immunodeficiency virus (HIV) impact of NA migrants to Europe is very low but a hallmark of the HIV epidemic is the penetration and circulation of non-B strains, recombinant forms and HIV-drug–resistant profiles through SSA migrants using NA as a transit point into Europe. Leishmaniasis is a re-emerging zoonotic disease prevalent to Southern Europe although not specifically isolated in migrant groups. Although not endemic in NA countries, malaria represents a risk in terms of re-emergence in Europe through transitory migrants arriving from SSA with the destination to Europe. Schistosomiasis has been largely eliminated from NA. High migrant flux into European countries has resulted in changing patterns of communicable disease and collectively requires a continuous surveillance. World Health Organization guidelines recommend targeted screening and preventative vaccination, followed by integration of migrants into the local health-care systems allowing for long-term treatment and follow-up. Finally, effective public health campaigns as a form of prevention are essential for the mitigation of disease dissemination in the migrant pool and for second-generation children of migrants.

16 August 2013 in BMC Infectious Diseases
Verified
Journal Article
Open access
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ZQZineb Qmichou
Zineb Qmichou
MKMeriem Khyatti
Meriem Khyatti
MBMohamed Berraho
Mohamed Berraho
MEMOULAY MUSTAPHA ENNAJI
MOULAY MUSTAPHA ENNAJI
LBLaila Benbacer
Laila Benbacer
MMMohammed EL MZIBRI
Mohammed EL MZIBRI
Background: Worldwide, cervical cancer is the second most common cancer in women. High-risk human papillomavirus (HPV) play a crucial role in the etiology of cervical cancer and the most prevalent genotype is HPV16. HPV 16 intratypic variants have been reported to differ in their prevalence, biological and biochemical properties. The present study was designed to analyze and identify HPV type 16 E6 variants among patients with cervical cancer in Morocco. Methods: A total of 103 HPV16 positive samples were isolated from 129 cervical cancer cases, and variant status was subsequently determined by DNA sequencing of the E6 gene. Results: Isolates from patients were grouped into the European (E), African (Af) and North-American (NA1) phylogenetic clusters with a high prevalence of E lineage (58.3%). The Af and NA1 variants were detected in 31.1% and 11.6% of the HPV16 positive specimens, respectively, whereas, only 3% of cases were prototype E350T. No European-Asian (EA), Asian (As) or Asian-American (AA) variants were observed in our HPV16-positive specimens. At the amino acid level, the most prevalent non-synonymous variants were L83V (T350G), H78Y (C335T), E113D (A442C), Q14D (C143G/G145T) and R10I (G132T), and were observed respectively in 65%, 41.8%, 38.8%, 30.1% and 23.3% of total samples. Moreover, HPV16 European variants were mostly identified in younger women at early clinical diagnosis stages. Whereas, HPV16 Af variants were most likely associated with cervical cancer development in older women with pronounced aggressiveness. Conclusion: This study suggests a predominance of E lineage strains among Moroccan HPV 16 isolates and raises the possibility that HPV16 variants have a preferential role in progression to malignancy and could be associated with the more aggressive nature of cervical cancer.

25 February 2011 in Infectious Agents and Cancer
Verified
Journal Article
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NFNajaf Allahyari Fard
Najaf Allahyari Fard
MAMohammed Attaleb
Mohammed Attaleb
MKMostafa Kandil
Mostafa Kandil
FNFadwa Naji
Fadwa Naji
TMTarik Mouttaki
Tarik Mouttaki
MKMeriem Khyatti
Meriem Khyatti
Background: Nasopharyngeal carcinoma (NPC) is a malignant tumor which arises in surface epithelium of the posterior wall of the nasopharynx. There's is evidence that Epstein Barr virus (EBV) is associated to NPC development. However, many epidemiologic studies point to a connection between viral infections by the human papillomavirus (HPV) and NPC. Method: Seventy Moroccan patients with NPC were screened for EBV and HPV. EBV detection was performed by PCR amplification of BZLF1 gene, encoding the ZEBRA (Z Epstein-Barr Virus Replication Activator) protein, and HPV infection was screened by PCR amplification with subsequent typing by hybridization with specific oligonucleotides for HPV types 16, 18, 31, 33, 35, 45 and 59. Results: The age distribution of our patients revealed a bimodal pattern. Sixty two cases (88.9%) were classified as type 3 (undifferentiated carcinoma), 6 (8.6%) as type 2 (non keratinizing NPC) and only 2 (2.9%) cases were classified as type 1 (keratinizing NPC). EBV was detected in all NPC tumors, whereas HPV DNA was revealed in 34% of cases (24/70). Molecular analysis showed that 20.8% (5/24) were infected with HPV31, and the remaining were infected with other oncogenic types (i.e., HPV59, 16, 18, 33, 35 and 45). In addition, statistical analysis showed that there's no association between sex or age and HPV infection (P > 0.1). Conclusion: Our data indicated that EBV is commonly associated with NPC in Moroccan patients and show for the first time that NPC tumours from Moroccan patients harbour high risk HPV genotypes.

1 January 2022 in Pan African Medical Journal
Verified
Journal Article
Open access
IAImane EL Alami
Imane EL Alami
AGAmina Gihbid
Amina Gihbid
HCHicham Charoute
Hicham Charoute
WKWafaa Khaali
Wafaa Khaali
SBSelma Mohamed Brahim
Selma Mohamed Brahim
MKMeriem Khyatti
Meriem Khyatti
The present meta-analysis was conducted to evaluate the prognostic value of pre and post-Epstein Barr Virus (EBV) DNA load testing and to assess the clinical benefit of using this molecular approach in the prognosis for a better nasopharyngeal carcinoma (NPC) management. Relevant studies were searched in different database until May 2020. Patient´s outcomes overall survival (OS), disease free survival (DFS), progression-free survival (PFS), distant-metastasis-free survival (DMFS), and local-regional-failure-free survival (LRFS), hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted from selected studies. The association of pre and post-EBV DNA load and survival outcomes was assessed using review manager and the pooled HRs with 95% CIs were calculated. Twenty-six eligible studies were included in this meta-analysis, with a total of 9966 patients. Pooled HRs showed that EBV DNA levels before and after treatment are significantly associated with survival outcomes, with HR (95% CI) of 2.09 [1.74, 2.51] for OS, 1.77 [1.19, 2.62] for DFS, 2.53 [2.18, 2.92] for DMFS, 1.78 [1.45, 2.19] for LRFS and 2.17 [1.91, 2.47] for PFS in pre-EBV DNA, and an HR (95%) of 4.52 [2.44, 8.36], 4.08 [2.38, 6.99], 5.59 [ 3.58, 8.71] and 8.88 [5.29, 14.90] for OS, DFS and PFS and DMFS in post-EBV DNA, respectively. High pre and post-EBV DNA levels were significantly associated with poor NPC patient´s survival outcomes; which clearly confirm the high interest to introduce viral EBV DNA load as a prognostic biomarker for NPC management.

22 August 2015 in Clinical Epigenetics
Verified
Journal Article
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INImran Nawaz
Imran Nawaz
KMKhalid Moumad
Khalid Moumad
DMDebora Martorelli
Debora Martorelli
MEMOULAY MUSTAPHA ENNAJI
MOULAY MUSTAPHA ENNAJI
XZXiaoying Zhou
Xiaoying Zhou
LHLifu Hu
Lifu Hu
Silencing of tumor suppressor genes (TSGs) or activation of oncogenes by, e.g., aberrant promoter methylation, may be early events during carcinogenesis. The methylation status of such genes can be used for early detection of cancer. We are pursuing this approach in our efforts to develop markers for early detection and follow-up of nasopharyngeal carcinoma (NPC). We set out to develop this approach to allow identification of NPC from Morocco and then also compared with NPC samples from different geographical locations and different ethnicity with different NPC incidences, Epstein-Barr virus (EBV) prevalence, and environments. By multiplex methylation-specific PCR (MMSP), multiple relevant genes can be detected simultaneously, to achieve high sensitivity and specificity. The strong association of EBV with NPC is also very useful in such an approach. We have initially screened for 12 potential marker genes including EBV genes coding for EBV nuclear antigen 1 (EBNA1) and latent membrane protein-1 (LMP1) and ten potential TSGs obtained from previously published data. The resulting assay included EBNA1, LMP1, and three cellular TSGs: ITGA9, RASSF1A, and P16. We evaluated this assay on 64 NPC patient biopsies from Morocco, Italy, and China compared to deoxyribonucleic acid (DNA) from 20 nasopharyngeal control tissues. In the Moroccan NPC cohort (n = 44), prevalence of the EBNA1 gene showed the highest sensitivity (36/44; 82 %) with 94 % specificity. Out of eight (18 %) EBNA1 negative Moroccan samples, only three were positive for at least one methylated cellular gene. By detection of cellular marker genes, the sensitivity increased from 82 to 89 % (39/44). In the whole material of 64 biopsies from three geographical locations, at least any one marker (viral or cellular) could be detected in 91 % of biopsies with 90 % specificity. In a pilot evaluating assay performance on serum DNA from NPC and controls including samples from Italy (n = 11) and China (n = 5), at least any one marker from the MMSP assay could be detected in 88 %, but the specificity was only 50 %. An MMSP assay has the potential for detection of NPC by screening in high-risk populations. Serum-derived DNA seems not as good as earlier published NPC swab DNA for screening purpose.

1 June 2018 in Papillomavirus Research
Verified
Journal Article
Open access
AEAmal ElAmrani
Amal ElAmrani
TGTarik Gheit
Tarik Gheit
BMBenhessou Mustapha Mustapha
Benhessou Mustapha Mustapha
SMSandrine McKay-Chopin
Sandrine McKay-Chopin
MAMohammed Attaleb
Mohammed Attaleb
MKMeriem Khyatti
Meriem Khyatti
Due to recent technical improvements and some encouraging new results, there has been a resurgence of interest in the possibility that a substantial proportion of breast cancers (BCs) may be caused by viral infections, including Human papillomavirus (HPV). The aim of this study was to determine the prevalence of mucosal and cutaneous HPV in tumours from Moroccan BC patients. Frozen tumours from 76 BC cases and 12 controls were evaluated for the presence of 62 HPV-types using highly sensitive assays that combine multiplex polymerase chain reaction and bead-based Luminex technology. HPV DNA was found in 25.0% of BC tumours and only 8.3% of controls. Beta and gamma HPV types were found in 10.5% and 6.6% of BC tumours, respectively. High-risk mucosal types HPV16 and 18 were not detected in the subjects, but other probable/possible high-risk or high-risk -HPV types (HPV51, 52, 58, 59, and 66) were found in 5.3% of BC tumours. Statistical analysis showed no significant difference between, controls, BC cases and the inflammatory status (p > 0.05). HPV DNA was found 3 times as frequently in the BC tumours as in the controls. However, this difference requires confirmation in a larger sample.