Zakaria Saied

Dr. Zakaria Saied

National Institute of Neurology Mongi-Ben Hamida, Tunis, Tunisia

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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20 April 2021 in Journal of Alzheimer’s Disease
Verified
Journal Article
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NJNajla Jouini
Najla Jouini
ZSZakaria Saied
Zakaria Saied
SSSamia Ben Sassi
Samia Ben Sassi
FNFatma Nebli
Fatma Nebli
TMTaieb Messaoud
Taieb Messaoud
SBSamir Belal
Samir Belal
Background: Iron plays an important role in maintaining cell survival, with normal iron trafficking known to be regulated by the ceruloplasmin-transferrin (Cp-Tf) antioxidant system. Disruption to this system is thought to be detrimental to normal brain function. Objective: To determine whether an imbalance of iron and the proteins involved in its metabolism (ceruloplasmin and transferrin) are linked to Alzheimer’s disease (AD) and to the expression of amyloid-beta (Aβ) peptide 1–42 (Aβ1–42), which is a major species of Aβ, and the most toxic. Methods: We evaluated the concentrations of iron, calcium, magnesium, and Aβ1–42 in the cerebrospinal fluid (CSF) of patients with AD and cognitively normal controls. Correlations between the components of the Cp-Tf antioxidant system in plasma were studied to determine the role of peripheral blood in the onset and/or development of AD. We used commercial ELISA immunoassays to measure Aβ1–42, immunoturbidimetry to quantify ceruloplasmin and transferrin, and colorimetry to quantify iron, calcium, and magnesium. Results: We found that the AD group had lower CSF concentrations of Aβ1–42 (p < 0.001) and calcium (p < 0.001), but a higher CSF concentration of iron (p < 0.001). Significantly lower plasma concentrations of ceruloplasmin (p = 0.003), transferrin (mean, p < 0.001), and iron (p < 0.001) were observed in the AD group than in cognitively normal adults. Moreover, we found a strong interdependence between most of these components. Conclusion: Iron dyshomeostasis has a crucial role in the onset of AD and/or its development. Correcting metal misdistribution is an appealing therapeutic strategy for AD.

29 April 2021 in Acta Neurologica Scandinavica
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Journal Article
Open access
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ZSZakaria Saied
Zakaria Saied
ARAmine Rachdi
Amine Rachdi
STSaber Thamlaoui
Saber Thamlaoui
FNFatma Nabli
Fatma Nabli
CJCyrine Jeridi
Cyrine Jeridi
SSSamia Ben Sassi
Samia Ben Sassi
Objective To describe presenting symptoms, clinical outcomes, and therapeutic management of concurrent Coronavirus disease 2019 (COVID‐19) infections in patients with a pre‐existing myasthenia gravis (MG). Methods We conducted a retrospective study in patients with preexisting MG presenting with concurrent COVID‐19 between September 21st and November 4th, 2020 when attending the emergency department or routine neurology consultation at the National Institute Mongi Ben Hamida of Neurology of Tunis, Tunisia. Results Five patients were identified. The Myasthenia Gravis Foundation of America scores (MGFA) prior to COVID‐19 infection were class I in one patient, class II (IIa, IIb) in two patients, and class IIIb in one patient. Four patients had mild to moderate courses of COVID‐19 infection. One patient presented a critical infection with acute respiratory disease syndrome (ARDS) requiring mechanical ventilation. Two of them also demonstrated signs of MG exacerbation requiring the use of intravenous immunoglobulin in one case. We maintained immunosuppressant therapy to MG in all our patients. All our patients received Azithromycin (AZM) as a part of specific drug treatment of COVID‐19 infection. Outcome was favorable in 4 patients and rapidly fatal evolution was observed in the patient with ADRS. Discussions and conclusion The results from our study suggest that prior MG activity could partially influence the subsequent clinical outcomes. It emerged also that ongoing long‐term immunosuppressive immunotherapy to MG should be maintained during the COVID‐19 pandemic and that AZM can be used safely in MG patients and concurrent COVID‐19 infection.

12 April 2022 in Cells
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Journal Article
Open access
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OMolfa maghrebi
olfa maghrebi
MBMeriam Belghith
Meriam Belghith
CJCyrine Jeridi
Cyrine Jeridi
ARAmine Rachdi
Amine Rachdi
FFFatma Nabli Fatnassi
Fatma Nabli Fatnassi
MBMohamed-Ridha Barbouche
Mohamed-Ridha Barbouche
Remitting-RelapsingMultiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuroinflammatory disorders leading to neurological damage. Herein, we investigated in these patients the IL-10-producing cells during the early stages of these disorders. Cellular and molecular investigations were carried out on treatment naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that CSF-B cells from NBD patients, but not RRMS, are the major source of intrathecal IL-10 as compared to T-CD4 cells. Moreover, we showed a lower expression of TGF-β and IL35, in the CSF cells of NBD patients as compared to the control group. Specific in vitro CpG stimulation of peripheral blood B cells from NBD patients resulted in a concomitant early mRNA expression of IL6 and IL10 but was limited to IL10 for RRMS patients. Furthermore, mRNA expression of IL-6 and IL-10 receptors was assessed and intriguingly IL6ST receptor subunit was significantly lower in NBD CSF, but not RRMS while IL10RB was increased in both. Deciphering the role of increased IL-10-producing B cells and IL10RB despite relapsing disease as well as the discordant expression of IL6 and IL6ST may pave the way for a better understanding of the pathophysiology of these neuro-inflammatory disorders.

Verified
Journal Article
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MBMeriam Belghith
Meriam Belghith
OMolfa maghrebi
olfa maghrebi
ACAroua Cherif
Aroua Cherif
KBkhadija bahrini
khadija bahrini
ZSZakaria Saied
Zakaria Saied
MKMariem Kchaou
Mariem Kchaou
When the central nervous system (CNS) is the primary affected site in an initial attack of Behçet’s disease (BD), the differential diagnosis is particularly challenging. Some cases remain unclassified or qualified as probable neuro-Behçet’s disease (NBD). Several cytokines are involved in the immunopathogenesis of this disease; however, studies establishing the differential cytokine pattern between probable and definite NBD are scarce. Twenty-eight parenchymal NBD patients, diagnosed according to the International Consensus Recommendation (ICR) criteria and classified into definite (D-NBD; n = 17) and probable (P-NBD; n = 11), were sampled at their first neurological symptoms, and compared with healthy control subjects (n = 20). Oligoclonal bands (OCB) of IgG were detected by isoelectric focusing on agarose, and immunoblotting of matched serum and cerebrospinal fluid (CSF) sample pairs. T cell cytokines (INF-γ, IL-4, IL-17, and IL-10) and transcription factors related to Th1, Th2, Th17, and T regulatory populations (respectively T-bet, GATA-3, ROR-γt, and Foxp3) were studied by quantitative RT-PCR in peripheral blood mononuclear cells (PBMCs) and CSF cells. Inflammatory cytokines such as IL-6, TNF-α, and IL-1β were also analyzed. CSF OCB pattern 2 was present in only 1 out of 28 neuro-Behçet’s patients who belonged to the P-NBD group. Two D-NBD patients had OCB in CSF showing pattern 4. In the D-NBD CSF samples, IL-17 and IL-10 expressions were significantly elevated compared to P-NBD. Moreover, D-NBD patients had increased levels of T-bet/GATA-3 and ROR-γt/Foxp3 ratios compared to P-NBD. Furthermore, a significant increase of CSF IL-6 in D-NBD, compared to P-NBD and the controls, was found. In addition to the increased IL-6 level, the data obtained suggest the existence in D-NBD patients of a significantly disrupted balance between Th17 effector and T regulatory cells, as reflected by the enhanced ROR-γt/Foxp3 ratio. This could be considered as an additional criterion for definite neuro-Behçet’s disease.

23 May 2022 in Journal of NeuroVirology
Verified
Journal Article
Closed access
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NFNabli Fatma
Nabli Fatma
ZSZakaria Saied
Zakaria Saied
ZMZouari Mourad
Zouari Mourad
BSBelal Samir
Belal Samir
SSSamia Ben Sassi
Samia Ben Sassi

22 April 2024 in Heliyon
Verified
Journal Article
Open access
ZSZakaria Saied
Zakaria Saied
RZRania Zouari
Rania Zouari
ARAmine Rachdi
Amine Rachdi
FNFatma Nabli
Fatma Nabli
DMDina Ben Mohamed
Dina Ben Mohamed
SSSamia Ben Sassi
Samia Ben Sassi
Primary Sjogren's syndrome (pSS) is an autoimmune exocrinopathy in which extraglandular signs of pSS are determinant for the prognosis. Involvement of both peripheral and central nervous system (CNS) are known to be among the sites of high systemic activity in pSS. We, herein, report a case of a 57-year-old female patient with pSS presenting with typical Guillan-Barré syndrome (GBS), shortly followed by acute headaches accompanied by cortical blindness. Cerebral magnetic resonance imaging (MRI) demonstrated T2 signal abnormalities on the occipital region with narrowing and irregularities of the cerebral arteries, suggestive of CNS vasculitis. Subtle sicca symptoms occurring prior to neurological symptoms by 8 months together with immunological disturbances (anti-SSA, anti-SSB antibodies positivity, type II cryoglobulins positivity, and C4 hypocomplementemia) allowed us to retain the diagnosis of pSS. Recovery of motor symptoms was possible under the combined use of immunoglobulins and corticotherapy during the initial phase. A three-years follow-up confirmed progressive motor recovery and stabilization under 6-months cyclophosphamide cycles relayed by azathioprine therapy. Neurological complications can be inaugural in lead to urgent investigations and treatment. Peripheral and central neurological manifestations can coexist. The approach should integrate careful clinical assessment, as well as radiological and immunological findings.