Si-yuan Fan

Dr. Si-yuan Fan

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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1 February 2018 in International Journal of Infectious Diseases
Verified
Journal Article
Open access
SFSi-yuan Fan
Si-yuan Fan
HRHaitao Ren
Haitao Ren
YWYanping Wei
Yanping Wei
CMChenhui Mao
Chenhui Mao
ZMZhenzi Ma
Zhenzi Ma
HGHongzhi Guan
Hongzhi Guan
Brucellosis is the most common zoonotic infection in the world. Brucellosis with nervous system involvement is known as 'neurobrucellosis' (NB). The diagnosis of NB is difficult because its clinical manifestations are non-specific and the sensitivity of routine culture tests is low. Next-generation sequencing (NGS) of cerebrospinal fluid (CSF) was used to detect pathogens in patients with clinically suspected central nervous system (CNS) infections at a tertiary referral center in China between June 1, 2016 and June 1, 2017. The clinical characteristics and NGS results of patients with the diagnosis of NB were reviewed in this study. Four patients were rapidly diagnosed with NB using NGS of the CSF in patients with clinically suspected CNS infections, although the clinical manifestations varied dramatically between these patients. NGS of the CSF revealed that the sequence reads identified that corresponded to Brucella species ranged from 11 to 104, with genomic coverage ranging from 0.043% to 0.4%. Rapid diagnosis led to prompt treatment with the appropriate antibiotics. This study demonstrates the power of NGS of the CSF coupled with a bioinformatic pipeline in the diagnosis of NB.

7 September 2020 in Asia-Pacific Journal of Clinical Oncology
Verified
Journal Article
Open access
PDF file
SFSi-yuan Fan
Si-yuan Fan
HRHaitao Ren
Haitao Ren
LZLuo Zhao
Luo Zhao
JYJian Yin
Jian Yin
GFGuodong Feng
Guodong Feng
HGHongzhi Guan
Hongzhi Guan
Immune checkpoint inhibitors (ICIs) have made a breakthrough in cancer therapy. Patients treated with ICIs may develop immune‐related adverse events (irAEs) due to the upregulated activity of the immune system. With the increasing use of ICIs, irAEs are more frequently reported and have become important challenges in many patients. Neurological irAEs, which include encephalitis, myelitis, aseptic meningitis, peripheral neuropathy, myasthenia gravis, and myositis, consist of a distinct group of neuroinflammatory disorders. These disorders are rare but frequently severe with high mortality and morbidity. Patients with neurological irAEs are generally responsive to immune‐modulating therapy. Therefore, early recognition and treatment are the most important ways to improve their prognosis. Here, we provide a comprehensive review of neurological irAEs associated with ICIs and focus on these affecting central nervous systems.

27 September 2021 in Neurology Neuroimmunology & Neuroinflammation
Verified
Journal Article
Open access
PDF file
MLMange Liu
Mange Liu
HRHaitao Ren
Haitao Ren
SFSi-yuan Fan
Si-yuan Fan
WZWeihe Zhang
Weihe Zhang
YXYao Xu
Yao Xu
TGthe Encephalitis Collaborative Group
the Encephalitis Collaborative Group
Background and Objective To present 6 new cases with Homer-3 antibodies that expand their clinical spectra and to evaluate the effect of immunotherapy. Methods Patients with suspected autoimmune cerebellar disorder were tested for rare autoimmune cerebellar ataxia (ACA) antibodies (anti-Tr(DNER)/Zic4/ITPR1/Homer-3/NCDN/PKCγ/PCA-2/AP3B2/mGluR1/ATP1A3 antibodies) using both cell-based and tissue-based assays. Patients with positive serum or CSF results who were diagnosed with ACA were registered and followed up. This study reports and analyzes cases with Homer-3 antibodies. Results Of the serum and CSF samples of 750 patients tested, 6 were positive for Homer-3 antibodies. All manifested subacute or insidious-onset cerebellar ataxia. Furthermore, 2 patients each exhibited encephalopathy, myeloradiculopathy, REM sleep behavior disorder, and autonomic dysfunction. Brain magnetic resonance images were normal (n = 1) or revealed cerebellar atrophy (n = 1), cerebellum and pons atrophy with the hot cross bun sign (n = 2), and bilateral cerebral abnormalities (n = 2). Definite leukocytosis was identified in the CSF of 2 patients, protein concentration elevation was observed in the CSF of 1 patient, and oligoclonal bands were present in 2 patients. All patients received immunotherapy, including corticosteroid, IV immunoglobulin, plasma exchange, and mycophenolate mofetil, after which the residual disability was still severe (modified Rankin Scale score ≥3 at the last follow-up in 4 patients and final Scale for the Assessment and Rating of Ataxia scores of 12–29), although 4 patients partially improved and 1 patient stabilized. The remaining 1 patient continued to deteriorate after repeated immunotherapy. Two patients relapsed. Discussion Disorders associated with Homer-3 antibody can mimic multiple system atrophy with cerebellar features in both clinical and radiologic aspects. Accurate identification of autoimmune-mediated cases is critical. Timely, comprehensive immunotherapy is warranted, given the possibility of long-term clinical benefit.

19 January 2026 in Diagnostics
Verified
Journal Article
Open access
PDF file
RBRui Ban
Rui Ban
YYYueyi Yu
Yueyi Yu
JJJingli Jiang
Jingli Jiang
DSDongchao Shen
Dongchao Shen
MLMange Liu
Mange Liu
HGHongzhi Guan
Hongzhi Guan
Background/Objectives : Anti-mGluR1 encephalitis is a rare form of autoimmune encephalitis predominantly manifesting as acute/subacute cerebellar ataxia. We describe a newly diagnosed case series from our center and conduct a comprehensive review of reported cases worldwide to compare clinical manifestations, treatment options, and outcomes. Methods: We consecutively identified 11 patients at Peking Union Medical College Hospital, and additionally extracted clinical data from 42 previously published cases identified via PubMed and Google Scholar (search updated to 1 August 2025). Demographics, phenotypes, laboratory findings, imaging, treatment, and outcomes were systematically summarized. This pooled review was not prospectively registered, and extracted data from 21 published articles were analyzed alongside our 11 newly diagnosed cases. Results: The integrated cohort comprised 53 patients with anti-mGluR1 encephalitis, including 29 males and 24 females, with patients reported from Asia (n = 18), North America (n = 11), and Europe (n = 24). The median age at onset was 50 years (IQR 29.5–58.5; range 3–81), with North American patients presenting later than their Asian and European counterparts (median 60 vs. 48 and 45 years, respectively; all p < 0.05). Disease onset was subacute in most cases (58.7%). Comorbid tumors were present in nine patients, most commonly lymphomas. Clinical phenotypes were classified as pure cerebellar syndrome (n = 31), cerebellar ataxia with encephalitic features (n = 20), and non-cerebellar presentations (n = 2). Baseline severity differed across phenotypes (χ2 = 35.7, p < 0.001). Regional variability in severity was observed but did not reach significance. CSF analyses revealed pleocytosis in 59% (23/39), elevated protein in 31.3% (5/16), and oligoclonal bands in 52.2% (12/23). MRI abnormalities were detected in 34.7% (17/49) of patients, with 21.9% (7/32) developing cerebellar atrophy on follow-up. Therapeutic strategies varied significantly across regions (p = 0.041), with Asian cohorts more frequently receiving long-term immunosuppression, European cohorts favoring combined regimens, and North American cases relying predominantly on first-line therapies. Overall, 65.9% (29/44) of patients clinically improved, 13.6% (6/44) relapsed and 20.5% (9/44) remained unaffected. Conclusions: Anti-mGluR1 encephalitis presents with significant clinical heterogeneity, ranging from cerebellar-dominant ataxia to neuropsychiatric or non-cerebellar phenotypes, and demonstrates differences in reported age of onset, disease severity, and therapeutic approaches across publication regions. Our findings underscore the importance of early recognition, sustained immunotherapy, and international collaboration to establish standardized, evidence-based management for this rare but disabling disorder.

1 January 2025 in Journal of Clinical Neurology
Verified
Journal Article
Open access
PDF file
CGChang Geng
Chang Geng
YJYalin Ju
Yalin Ju
JWJing Wang
Jing Wang
WZWeihua Zhang
Weihua Zhang
XYXiao Yang
Xiao Yang
HGHongzhi Guan
Hongzhi Guan
Geng C, et al. J Clin Neurol. 2025 Jun;21:e20. https://doi.org/10.3988/jcn.2025.0061

1 September 2024 in Journal of Digestive Diseases
Verified
Journal Article
Closed access
YSYing Hao Sun
Ying Hao Sun
XBXiaoyin Bai
Xiaoyin Bai
TGTao Guo
Tao Guo
SFSi-yuan Fan
Si-yuan Fan
GRGe Chong Ruan
Ge Chong Ruan
HYHong Yang
Hong Yang