Central Nervous System Infection Research Articles

Microglia influence immune responses and restrict neurologic disease in response to central nervous system infection by a neurotropic murine coronavirus.

Intracranial (i.c.) inoculation of susceptible mice with a glial-tropic strain of mouse hepatitis virus (JHMV), a murine coronavirus, results in an acute encephalomyelitis followed by viral persistence in white matter tracts accompanied by chronic neuroinflammation and demyelination. Microglia serve numerous functions including maintenance of the healthy central nervous system (CNS) and are among the first responders to injury or infection. More recently, studies have demonstrated that microglia aid in tailoring innate and adaptive immune responses following infection by neurotropic viruses including flaviviruses, herpesviruses, and picornaviruses. These findings have emphasized an important role for microglia in host defense against these viral pathogens. In addition, microglia are also critical in optimizing immune-mediated control of JHMV replication within the CNS while restricting the severity of demyelination and enhancing remyelination. This review will highlight our current understanding of the molecular and cellular mechanisms by which microglia aid in host defense, limit neurologic disease, and promote repair following CNS infection by a neurotropic murine coronavirus.

NLRP3/Caspase 1/Gsdmd Mediated Pyroptosis Exerts a Crucial Role in Blood-Brain Barrier Pathological Injury Induced By Cryptococcus Neoformans

Background: Cryptococcus neoformans (Cn) traversal of the blood-brain barrier (BBB), composed of human brain microvascular endothelial cells (HBMECs), is a critical process in central nervous system infection. Previous studies have achieved significant progress in pathogenic mechanisms how Cn penetrates BBB. However, it is still largely elusive about the cellular and molecular mechanism of the abrasive interaction between Cn and HBMECs. Here, we focus on the pathogenesis of direct damage to the HBMECs by Cn. Methods: The immortalized HBMECs were incubated with Cryptococcus neoformans strain B-4500FO2 in different final concentrations (1×10^6/mL, 1×10^7/mL) for 3 hours at 37℃. The control group was treated with isovolumic phosphate buffered saline. Then, total soluble proteins of HBMECs in each group were extracted with RIPA lysis buffer for immunoblotting analysis. ImageJ and SPSS software were used for grayscale and statistical analysis respectively. Results: We found that the expression levels of pyroptosis-related protein, including NLRP3, Caspase 1, N-terminal of GSDMD especially, were significantly upregulated in HBMECs treated with higher concentrations (1×10^7/mL) of Cn compared to control group ( P < 0.05), in spite of the fact that there was no statistically significant difference in the expression of GSDMD ( P > 0.05). Conclusion: These data support that Cn might impair BBB through facilitating pyroptosis of HBMECs via NLRP3/Caspase 1/GSDMD signaling. More intensive investigations are still required to elucidate the underlying mechanism how pyroptosis is triggered and transmitted in the interaction between Cn and HBMECs. ( Acknowledgements: Undergraduate Training Program for Innovation and Entrepreneurship of SMU, China, No. 202312121330; Corresponding author: Hong Cao, gzhcao@smu.edu.cn )

The Risk of Infections in Adults with Primary Immune Thrombocytopenia (ITP)

Background Immunosuppressive treatment has remained a cornerstone in the management of primary ITP (pITP) for decades. Infections are known complications to immunosuppressive therapy, but the actual risk is not well studied in ITP. We have previously shown that the overall mortality risk is increased in pITP patients and specifically that death due to infections is 1.5-2.4-fold elevated compared to the general population. In this study,we aimed at quantifying the risk of infection, including infection subtypes, in adults with pITP and matched comparators from the general population. Study design We constructed a nationwide cohort of patients ≥18 years with pITP using the Danish Civil Registration System (CRS) and the Danish National Patient Registry (DNPR). We identified ITP patients using the specific ICD-10 diagnosis registration and age-sex matched these with up to 40 comparators without ITP from the general population. We excluded prevalent ITP, non-ITP thrombocytopenic disorders, and secondary ITP defined as one or more associated diagnosis registered any time before or up to 30 days after diagnosis of ITP. The latter included ITP in combination with hematological malignancies, autoimmune disorders etc. Hospital registered infections were identified through the DNPR, prior to 1995 using ICD-8 and ICD-10 diagnoses codes thereafter. Diagnosis codes were grouped, defining the following seven types or sites of infection: respiratory, urogenital, bloodstream, gastrointestinal, tissue and musculoskeletal, central nervous system (CNS), candidiasis and other fungal infections. Date of first registration of pITP marked start of follow-up and comparators were assigned the same start date. Patients and comparators were followed to the first of following events in each of the seven subgroups: infection, emigration, death, or end of study period (31 st of December 2016). Infections occurring before start date were categorized as prevalent. We computed 1-year, 5-year, and 10-year as well as overall cumulative incidences. In addition, relative increases in risk were estimated using Cox-specific hazard (csHR) and Fine-Gray subhazard ratios (subHR) with and without equivalent time-splits, and death as competing event. Results We identified 4,030 pITP patients and 161,020 matched comparators. In the combined group of all types of infections total follow-up time was 22,075 person-years (average 5.5 years) for pITP patients and 1,118,304 person-years (average 6.9 years) for comparators. Median age was 60 years [IQR 40-74]. Previous hospital registered infections had occurred in 37% of patients and 27% of comparators. Comorbidity was more frequent among pITP patients than among comparators. The 1-year cumulative incidences in all subgroups of infections were higher in patients compared with the general population (Figure 1). For blood stream infections the 1-year cumulative incidence reached 3.36% [95% CI 2.83-3.96] in patients and 0.47% [95% CI 0.44-0.51] in comparators. The cumulative incidences for all subtypes of infections remained higher for patients than comparators throughout the study period, but differences decreased over time. During the first year adjusted csHR for infections overall was 2.82 [95%CI 2.61-3.05] and the adjusted subHR was 2.20 [95% CI 2.01-2.41]. Blood stream infections had the relative highest risk with an adjusted csHR of 6.58 [95% CI 5.46-7.92] and adjusted subHR of 2.08 [95% CI 1.71-2.54] (Figure 2). Risks of the other types of infections were also increased during first year but diminished over time in general (Figure 2). For the entire study period the overall adjusted csHR of all infections was 1.51 [95% CI 1.35-1.67] with a subHR of 1.34 [95% CI 1.20-1.49]. Blood stream infections continued having the highest risk in the period between 6 th-10 th year with a csHR of 1.40 [95% CI 1.03-1.91]. Conclusion The risk of incident infection in patients with pITP is increased compared with the general population. This risk is especially elevated within the first year after diagnosis but remains higher than the general population also in subsequent years. The risk of blood stream infection is especially high within the first year after diagnosis, but remains higher even 20 years after diagnosis. These data may help clinicians to improve management of ITP and support shared decision making with patients.

Central nervous system infection in a pediatric population in West Java.

Central nervous system (CNS) viral infections are critical causes of morbidity and mortality in children; however, comprehensive data on etiology is lacking in developing countries such as Indonesia. To study the etiology of CNS infections in a pediatric population, 50 children admitted to two hospitals in Bandung, West Java, during 2017-2018 were enrolled in a CNS infection study. Cerebrospinal fluid and serum specimens were tested using molecular, serological, and virus isolation platforms for a number of viral and bacteriological agents. Causal pathogens were identified in 10 out of 50 (20%) and included cytomegalovirus (n = 4), Streptococcus pneumoniae (n = 2), tuberculosis (n = 2), Salmonella serotype Typhi (n = 1) and dengue virus (n = 1). Our study highlights the importance of using a wide range of molecular and serological detection methods to identify CNS pathogens, as well as the challenges of establishing the etiology of CNS infections in pediatric populations of countries with limited laboratory capacity.

819. Experience with Isavuconazole Use for Treatment of Invasive Fungal Infections

Abstract Background The treatment of invasive fungal infections (IFI) is often complicated by drug-drug interactions, toxicities, and host comorbidities. Isavuconazole (ISA) has a favorable side effect profile and has FDA approval for invasive aspergillosis and mucormycosis, but there are fewer data on its efficacy for other microbes and non-pulmonary infections. We report our experience of ISA in IFI treatment, with a particular focus on non-pulmonary sites and other microbial etiologies. Methods We identified patients who received ISA as part of IFI treatment from 1/1/2015–4/1/2020 at Mayo Clinic. We categorized them by organ involvement and by pathogens, and identified patterns of ISA use and clinical outcomes. Results A total of 131 patients were identified. Similar to the existing literature, the majority were pulmonary infections (60%), with 12% invasive sinus infection, 12% central nervous system (CNS) infection, and 7% fungemia. Aspergillus was the most common pathogen (39%), yeast comprised 19%, dimorphic fungi 15%, Mucormycosis 12%, phaeohyphomycosis 5%, and other molds 3%. ISA was used as secondary/salvage therapy in 89% of cases. The response rate varied by organ involvement and pathogen. ISA had complete/partial resolution or achieved stability in 57% of fungemia cases, 63% of invasive sinus infections, 64% of pulmonary infections, and 73% of CNS infections. Aspergillus species had a 67% response rate, with 72% response in yeast infections, 65% rate in dimorphic fungi, 53% for mucormycosis, and 86% in dematiaceous molds. Conclusion Although limited by a small sample size, the subgroup review based on organ site and microbial etiology did seem to show roughly similar results to approved uses. The CNS infections treated with ISA were particularly of interest, given the limited options available with reliable CNS penetration. The current available literature has little to say on the efficacy of ISA in these off-label uses, with the majority being similar case series. This report highlights the importance of prospective trials comparing ISA to other antifungals in a greater variety of indications to better identify when this better-tolerated agent can be safely used. Disclosures Courtney E. Harris, MD, Dynamed: Advisor/Consultant

Streptococcus gordonii infective endocarditis complicated by brain abscess in a patient with a congenital bicuspid aortic valve: a case report

Abstract Background Infective endocarditis is associated with significant morbidity and mortality. Oral trauma through dental procedures can result in infective endocarditis through displacement of commensal organisms into the bloodstream. Streptococcus gordonii is an oral commensal and is rarely implicated as a cause of infective endocarditis but should be considered in febrile patients with a recent history of odontological procedures. Case summary We present a case of a previously healthy 26-year-old woman who presented with a 2-month history of fevers. Blood cultures on admission were positive for S. gordonii. Echocardiography demonstrated a congenital bicuspid aortic valve with vegetations and abscess, supporting a diagnosis of infective endocarditis. A magnetic resonance imaging (MRI) brain revealed a small cerebral empyema. She was treated with intravenous antibiotics and underwent an aortic valve replacement. Discussion Bicuspid aortic valve predisposes to infective endocarditis, and these patients have higher incidence of requiring cardiac surgery. Streptococcus gordonii belongs to the viridans group streptococci that are recognized as causative organisms for infective endocarditis particularly where dental sources are suspected. Patients with infective endocarditis may develop neurological sequelae including cerebrovascular accidents or central nervous system infections. If risk of haemorrhagic transformation is low, surgical intervention for valve replacement should not be delayed.

Complications of Intracranial Multimodal Monitoring for Neurocritical Care: A Systematic Review and Meta-Analysis.

Intracranial multimodal monitoring (iMMM) is increasingly used for neurocritical care. However, concerns arise regarding iMMM invasiveness considering limited evidence in its clinical significance and safety profile. We conducted a synthesis of evidence regarding complications associated with iMMM to delineate its safety profile. We performed a systematic review and meta-analysis (PROSPERO Registration Number: CRD42021225951) according to the Preferred Reporting Items for Systematic Review and Meta-Analysis and Peer Review of Electronic Search Strategies guidelines to retrieve evidence from studies reporting iMMM use in humans that mention related complications. We assessed risk of bias using the Newcastle-Ottawa Scale and funnel plots. The primary outcomes were iMMM complications. The secondary outcomes were putative risk factors. Of the 366 screened articles, 60 met the initial criteria and were further assessed by full-text reading. We included 22 studies involving 1206 patients and 1434 iMMM placements. Most investigators used a bolt system (85.9%) and a three-lumen device (68.8%), mainly inserting iMMM into the most injured hemisphere (77.9%). A total of 54 postoperative intracranial hemorrhages (pooled rate of 4%; 95% confidence interval [CI] 0-10%; I2 86%, p < 0.01 [random-effects model]) was reported, along with 46 misplacements (pooled rate of 6%; 95% CI 1-12%; I2 78%, p < 0.01) and 16 central nervous system infections (pooled rate of 0.43%; 95% CI 0-2%; I2 64%, p < 0.01). We found 6 system breakings, 18 intracranial bone fragments, and 5 cases of pneumocephalus. Currently, iMMM systems present a similar safety profile as intracranial devices commonly used in neurocritical care. Long-term outcomes of prospective studies will complete the benefit-risk assessment of iMMM in neurocritical care. Consensus-based reporting guidelines on iMMM use are needed to bolster future collaborative efforts.

STREPTOCOCCUS SUIS INFECTION (DIAGNOSIS, PREVENTION AND TREATMENT)

Streptococcus suis (S. suis) is an important zoonotic pathogen, which can cause serious diseases such as meningitis, pneumonia, endocarditis, polyserositis, arthritis, septicemia and abortion in pigs. In recent years, the incidence rate of streptococcal meningitis has shown a significant upward trend. For humans, the threat of S. suis is also increasing. Therefore, strengthening the prevention and control of the disease has become an urgent task. The premise of inducing meningitis is that S. suis invades the central nervous system and breaches the blood brain barrier (BBB). Due to the presence of the blood brain barrier, even though bacteria can enter the blood through the skin mucosa and other parts, a large number of bacteria in the blood cannot enter the brain through the blood brain barrier. The body relies on this barrier to protect the brain tissue from damage and maintain the homeostasis of the central nervous system. Brain microvascular endothelial cell (BMEC) is the basic component of the blood brain barrier, and a variety of neurological diseases are related to the dysfunction of the blood brain barrier, and S. suis can interact with brain microvascular endothelial cell and then cross the the blood brain barrier to cause central nervous system infection. However, the antibiotics used to treat the infection cannot pass through the barrier to reach the therapeutic target site, which is the key to the difficulty in the control of bacterial meningitis. Therefore, elucidating the mechanism of S. suis breaking through the blood brain barrier into central nervous system is an important breakthrough in developing S. suis meningitis control strategy. Due to long-term unjustified use of antibiotics, bacterial resistance has increased, and antibiotic treatment disrupts the normal homeostasis of the body and intestinal flora. The problems caused by long-term, large-scale use of antibiotics are becoming more and more serious. Meningitis caused by streptococcus suis can no longer be treated with conventional antibiotics. Therefore, It is necessary to have a thorough understanding of the pathogenesis of meningitis. This article reviews the discovery the clinical signs and symptoms of the disease, pathological changes, laboratory, measures of prevention and treatment for streptococcal infection of pigs in recent years.

Pathogen quantitative efficacy of different spike-in internal controls and clinical application in central nervous system infection with metagenomic sequencing.

Metagenomic next-generation sequencing (mNGS) has been used broadly for pathogens detection of infectious diseases. However, there is a lack of method for the absolute quantitation of pathogens by mNGS. We compared the quantitative efficiency of three mNGS internal controls (ICs) Thermus thermophilus, T1 phages, and artificial DNA sequence and developed the most applicable strategies for pathogen quantitation via mNGS in central nervous system infection. The IC application strategy we developed will enable mNGS analysis to assess the pathogen load simultaneously with the detection of pathogens, which should provide critical information for quick decision-making of treatment as well as clinical prognosis.

Comparison of clinical and microbiological characteristics of community-acquired hypervirulent Klebsiella pneumoniae liver abscess in diabetic and non-diabetic patients.

Invasive infection caused by hypervirulent Klebsiella pneumoniae (HvKP) has been reported worldwide. Most of the patients are community population, related to diabetes mellitus (DM), chronic liver disease and other basic diseases, which prone to systemic migratory infection. In this study, we collected 377 patients with community acquired Klebsiella pneumoniae liver abscess in our hospital from January 2013 to December 2018, 65.8% of whom were male, and 49.6% had DM. Patients with DM are prone to eye and central nervous system (CNS) infection, which need continuous local abscess drainage during treatment. Among them, patients with poor blood glucose control have a higher rate of blood stream infections (BSI). 219 strains of HvKP were obtained, with K1/K2 Serotype accounted for 81.7%. The incidence of BSI in K2 patients was higher than that in K1 patients. The PCR results indicate that the carrying rate of virulence genes (rmpA、areo、kfu、allS、iroN、magA、uge、wcaG) in K1/K2 type strains is significantly higher than that in non K1/K2 type strains. ST23 and ST65 are the most common multilocus sequence typing (MLST), which belong to K1 and K2 Serotype respectively. All of HvKP strains showed high sensitivity to commonly used clinical antibiotics other than ampicillin, with 54.3% of the strains exhibiting high viscosity characteristics. Meanwhile, 35 classic Klebsiella pneumoniae (cKP) strains were collected, and their serum typing is mainly non K1/K2. The carrying rate of virulence genes and viscosity degree in HvKP are significantly higher than those in cKP. Primary liver abscess caused by HvKP is prone to multiple tissue and organ infections, but it shows higher sensitivity to most commonly used antibiotics in clinical practice except for ampicillin. After effective treatment, the overall prognosis of patients is better. This study analyzes the pathogenic characteristics of HvKP and elaborates on the clinical characteristics of patients, which can provide reference for clinical and scientific research work.

Natural Terpenes Inhibit the Cytopathogenicity of Naegleria fowleri Causing Primary Amoebic Meningoencephalitis in the Human Cell Line Model.

Naegleria fowleri is one of the free-living amoebae and is a causative agent of a lethal and rare central nervous system infection called primary amoebic meningoencephalitis. Despite the advancement in antimicrobial chemotherapy, the fatality rate in the reported cases is more than 95%. Most of the treatment drugs used against N. fowleri infection are repurposed drugs. Therefore, a large number of compounds have been tested against N. fowleri in vitro, but most of the compounds showed high toxicity. To overcome this, we evaluated the effectiveness of naturally occurring terpene compounds against N. fowleri. In this study, we evaluated the antiamoebic potential of natural compounds including Thymol, Borneol, Andrographolide, and Forskolin againstN. fowleri. Thymol showed the highest amoebicidal activity with IC50/24 h at 153.601 ± 19.6 μM. Two combinations of compounds Forskolin + Thymol and Forskolin + Borneol showed a higher effect on the viability of trophozoites as compared to compounds alone and hence showed a synergistic effect. The IC50 reported for Forskolin + Thymol was 81.30 ± 6.86 μM. Borneol showed maximum cysticidal activity with IC50/24 h at 192.605 ± 3.01 μM. Importantly, lactate dehydrogenase release testing revealed that all compounds displayed minimal cytotoxicity to human HaCaT, HeLa, and SH-SY5Y cell lines. The cytopathogenicity assay showed that Thymol and Borneol also significantly reduced the host cell cytotoxicity of pretreated amoeba toward the human HaCaT cell line. So, these terpene compounds hold potential as therapeutic agents against infections caused by N. fowleri and are potentially a step forward in drug development against this deadly pathogen as these compounds have also been reported to cross the blood-brain barrier. Therefore, an in vivo study using animal models is necessary to assess the efficacy of these compounds and the need for further research into the intranasal route of delivery for the treatment of these life-threatening infections.

Multiantigen print immunoassay (MAPIA) for the diagnosis of neurocysticercosis: a single-center diagnostic optimization and accuracy study in Lima, Peru.

Neurocysticercosis (NCC) is the most common helminthic infection of the human central nervous system. The antibody detection assay of choice is the enzyme-linked immunoelectrotransfer blot assay using lentil-lectin purified parasite antigens (LLGP-EITB, Western blot), an immunoassay with exceptional performance in clinical samples. However, its use is mainly restricted to a few research laboratories because the assay is labor-intensive and requires sophisticated equipment, expertise, and large amounts of parasite material for preparation of reagents. We report a new immunoprint assay (MAPIA) that overcomes most of these barriers. We initially compared the performance of five different antigen combinations in a subset of defined samples in the MAPIA format. After selecting the best-performing assay format (a combination of rGP50 + rT24H + sTs14 antigens), 148 archived serum samples were tested, including 40 from individuals with parenchymal NCC, 40 with subarachnoid NCC, and 68 healthy controls with no evidence of neurologic disease. MAPIA using three antigens (rGP50 + rT24H + sTs14) was highly sensitive and specific for detecting antibodies in NCC. It detected 39 out of 40 (97.5%) parenchymal NCC cases and 40/40 (100%) subarachnoid cases and was negative in 67 out of 68 (98.53%) negative samples. MAPIA using three recombinant and synthetic antigens is a simple and economical tool with a performance equivalent to the LLGP-EITB assay for the detection of specific antibodies to NCC. The MAPIA overcomes existing barriers to adoption of the EITG LLGP and is a candidate for worldwide use.

Optic nerve sheath diameter and severity of central nervous infection

Background Central nervous system (CNS) infection affects the brain, and can cause cerebral edema, increased intracranial pressure (ICP), cerebral herniation, and death. Measurement of the optic nerve sheath diameter (ONSD) by ultrasound is a new, non–invasive examination to predict ICP, with high sensitivity and specificity.Objective To analyze for a possible association between ONSD measured by ultrasonographic examination and severity of CNS infection.&#x0D; Methods This cross–sectional study was performed in the Pediatric Department of Hasan Sadikin Hospital, Bandung, West Java. Subjects were chosen by consecutive sampling. We measured ONSD, examined clinical manifestations, as well as performed a cerebrospinal fluid (CSF) study and imaging of CNS infection. Data analysis was done by paired T–test and one–way ANOVA, followed by Tukey test on significant variables.&#x0D; Results Subjects consisted of 32 children with CNS infection. The most common clinical symptoms were fever, decreased consciousness, and nuchal rigidity. Bivariate analysis revealed strong positive associations between ONSD and Glasgow Coma Scale (GCS), increased protein levels in CSF, and type of CNS infection.&#x0D; Conclusion Larger ONSD is significantly associated with lower GCS, increases CSF protein, and particular CNS infections. The ONSD is also associated with meningitis tuberculosis grade III, with a higher mean ONSD of both eyes compares to other CNS infections. Hence, the higher the ONSD, the more severe the degree of CNS infection.

Characteristics and long-term prognosis of Danish residents with a positive intrathecal antibody index test for herpes simplex virus or varicella-zoster virus compared with individuals with a positive cerebrospinal fluid PCR: a nationwide cohort study

ObjectivesWe compared characteristics and outcomes of individuals who in the cerebrospinal fluid (CSF) were positive for herpes simplex virus (HSV) or varicella-zoster virus (VZV)-intrathecal antibody index test ([AI]-positive) vs. individuals who were PCR-positive for HSV type 1 (HSV1), type 2 (HSV2), and for VZV. MethodsNationwide cohort study of all Danish residents with positive CSF-AI or -PCR for HSV or VZV (1995–2021). We calculated short- and long-term risks as age-, sex-, and comorbidity-adjusted odds ratios (aOR), adjusted hazard ratios (aHR), and absolute risk differences with 95% CIs. ResultsCompared with individuals with positive PCR for HSV1 (n = 321), HSV2 (n = 497), and VZV (n = 1054), individuals with a positive AI for HSV (n = 177) and VZV (n = 219) had CSF pleocytosis less frequently (leucocyte count >10/μL: HSV-AI: 39%, VZV-AI: 52%, HSV1-PCR: 81%, HSV2-PCR: 92%, VZV-PCR: 83%), and were less frequently diagnosed with central nervous system infection ([aOR {95%CI}]: HSV-AI vs. HSV1-PCR: [0.1 {0.1, 0.2}], HSV-AI vs. HSV2-PCR: [0.1 {0.0, 0.1}], VZV-AI vs. VZV-PCR: [0.2 {0.2, 0.3}]). Individuals with a positive HSV-AI or VZV-AI had increased risk of demyelinating disease ([aOR {95%CI}; aHR {95%CI}]: HSV-AI vs. HSV1-PCR: [4.6 {0.9, 24.5}; aHR not applicable], HSV-AI vs. HSV2-PCR: [10.4 {2.3, 45.9}; 12.4 {2.3, 66.0}], VZV-AI vs. VZV-PCR: [aOR not applicable; 10.3 {1.8, 58.8}]). Disability pension was less frequent among HSV-AI than HSV1-PCR cohort members (5-year risk difference: −23.6%, 95%CI: −35.2, −11.8), and more frequent among VZV-AI than VZV-PCR cohort members (5-year risk difference: 16.8%, 95%CI: 5.0, 28.7). DiscussionAI-positive individuals differ from PCR-positive individuals in several aspects. AI appears unspecific for current central nervous system infections.

Clinical manifestations and outcome of patients with primary amoebic meningoencephalitis in Pakistan. A single-center experience.

Primary amoebic meningoencephalitis (PAM) is a rapidly progressing central nervous system (CNS) infection caused by Naegleria fowleri, a free-living amoeba found in warm freshwater. The disease progression is very rapid, and the outcome is nearly always fatal. We aim to describe the disease course in patients admitted with PAM in a tertiary care center in Karachi, Pakistan between the periods of 2010 to 2021. A total of 39 patients were included in the study, 33 males (84.6%). The median age of the patients was 34 years. The most frequent presenting complaint was fever, which was found in 37 patients (94.9%) followed by headache in 28 patients (71.8%), nausea and vomiting in 27 patients (69.2%), and seizures in 10 patients (25.6%). Overall, 39 patients underwent lumbar puncture, 27 patients (69.2%) had a positive motile trophozoites on CSF wet preparation microscopy, 18 patients (46.2%) had a positive culture, and 10 patients had a positive PCR. CSF analysis resembled bacterial meningitis with elevated white blood cell counts with predominantly neutrophils (median, 3000 [range, 1350-7500] cells/μL), low glucose levels median, 14 [range, 1-92] mg/dL), and elevated protein levels (median, 344 [range, 289-405] mg/dL). Imaging results were abnormal in approximately three-fourths of the patients which included cerebral edema (66.7%), hydrocephalus (25.6%), and cerebral infarctions (12.8%). Only one patient survived. PAM is a fatal illness with limited treatment success. Early diagnosis and prompt initiation of treatment can improve the survival of the patients and reduce mortality.

Metagenomic next-generation sequencing for diagnosis of infectious encephalitis and meningitis: a retrospective study of 90 patients

ABSTRACT Background Infections of the central nervous system (CNS) are potentially life-threatening and can cause serious morbidity. We evaluated the clinical value of metagenomic next-generation sequencing (mNGS) in the diagnosis of infectious encephalitis and meningitis and explored the factors affecting the results of mNGS. Methods Patients with suspected cases of encephalitis or meningitis who presented in Northern Jiangsu People’s Hospital from 1 March 2018 to 30 September 2022 were collected. Demographic, historical, and clinical information were obtained, and cerebrospinal fluid (CSF) samples were treated with mNGS. The pathogen was identified using National Center for Biotechnology Information (NCBI) GenBank sequence data. Results Ninety-six patients were screened and finally 90 subjects enrolled. Of the 90 enrolled cases, 67 (74.4%) were diagnosed with central nervous system infections, which included 48 cases (71.6%) of viral infection, 11 (12.2%) of bacterial infection, 5 (7.5%) of mycobacterium tuberculosis, 2 (3.0%) of fungal infection, and 1 (1.5%) of rickettsia infection. From these cases, mNGS identified 40 (44.4%) true-positive cases, 3 (3.3%) false-positive case, 22 (24.4%) true-negative cases, and 25 (27.8%) false-negative cases. The sensitivity and specificity of mNGS were 61.5% and 88%, respectively. mNGS of CSF could show a higher positive rate in patients with marked CSF abnormalities, including elevated protein concentrations and monocyte counts. Conclusion mNGS of CSF is an effective method for detecting infectious encephalitis and meningitis, and the results should be analyzed combined with conventional microbiological testing results.

Neither Conditioning Chemotherapy Nor GvHD-Prophylaxis: CD7 CAR-T Treatment Bridging to Haplo-HSCT

BACKGROUND: Relapsed/refractory (R/R) acute leukemia patients ineligible for allo-HSCT have poor prognosis. CAR-T therapy has shown promising therapeutic outcomes for these patients, but simultaneously confers the risk of pancytopenia and potential tumor relapse. Bridging CAR-T therapy with allo-HSCT has the potential to restore hematopoiesis and consolidate long-term efficacy. However, GvHD remains a major impediment, and the myeloablative conditioning regimen eradicates residual CAR-T cells and compromises CAR-mediated antitumor function. Furthermore, the implementation of conditioning regimen and GvHD-prophylaxis could lead to severe toxicities. Novel strategies are therefore warranted to preserve CAR-T cells, enhance antitumor potency and minimize complications. METHODS: In this study, we presented 10 patients (enrolled between November 2021 and June 2023) with R/R CD7-positive acute leukemia who proceeded directly to haploidentical HSCT (haplo-HSCT) after CAR-T therapy. All patients received allogeneic CD7 CAR-T therapy, manufactured from either haploidentical donors (n=8) in a phase I clinical trial of donor-derived CAR-T cells (NCT04599556) or (n=1) universal CD7 CAR-T cells (RD13-02) therapy (NCT05716113) or as a compassionate use program after the end of a phase I clinical trial of universal CD7 CAR-T cells (RD13-01) (NCT04538599). CAR-T cell doses were at 2´10 6(haploidentical donor, n=8), 4´10 6 (RD13-02, n=1) or 5´10 6 (RD13-01, n=1) cells/kg. After achieving complete remission with incomplete hematological recovery (CRi), all patients underwent haplo-HSCT without conditioning regimen or GvHD prophylaxis. The primary end point was efficacy, safety, hematopoiesis recovery, and donor chimerism. RESULTS: All patients relapsed from multiple lines of chemotherapy or immunotherapy (median, 7; range, 4-13), were ineligible for allo-HSCT and received palliative care. After CAR-T infusion, 9 patients achieved MRD-negative CRi, and 1 achieved MRD-positive CRi, on day 15 after CD7 CAR-T therapy. 9 patients developed grade 1-2 cytokine release syndrome, and no neurological toxicity was reported. All patients exhibited grade 4 pancytopenia and bone marrow hypocellularity and were directly bridging to haplo-HSCT. The median time from CAR-T infusion to haplo-HSCT was 19 (range, 15-89) days. One patient died of HHV6 infection in central nervous system on day 13 after haplo-HSCT and was not evaluable for the following safety and efficacy. 3 patients experienced short-term grade II acute GvHD, which was resolved completely after low dose steroid, anti-TNF-α or ruxolitinib therapy. One patient developed PTLD at 2.1 months post-HSCT. In 9 evaluable patients, 8 showed full donor chimerism at 1-month post-HSCT, and 1 showed autologous hematopoiesis recovery. At a median follow-up of 10.2 (range, 2.2-20.7) months after CAR-T therapy, 6 patients remained in MRD-negative CR with normal hematopoiesis (including the patient with autologous hematopoietic recovery), 1 had CD7-negative relapse at 5.6 months, 1 developed CD7-negative relapse at 4.3 months and died at 4.8 months, and 1 died from septic shocks at 3.7 months. OS, PFS, NRM, and CIR at 1 year were 64.3% (95% CI, 38.5%-100%), 51.4% (95% CI, 26.2%-100%), 22.9% and 25.7%, respectively. Peripheral normal T cells in 8/10 of patients remained CD7-negative at the last follow-up, illustrating a well-maintained CAR-T function post-HSCT. CONCLUSIONS: Our findings demonstrate a novel strategy to simultaneously achieve CAR-T persistence and complete HSC engraftment, while reducing the risks of GvHD, providing valuable insights into combining cellular therapy with allo-HSCT for the treatment of R/R acute leukemia patients ineligible for conventional allo-HSCT.

Clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion in children

Objective: To explore the clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion(AESD) in children. Methods: For the case series study, 21 children with AESD from Peking University First Hospital, Provincial Children's Hospital Affiliated to Anhui Medical University, Children's Hospital of Fudan University, and Shanxi Children's Hospital who were diagnosed and treated from October 2021 to July 2023 were selected. Clinical data were collected to summarize their clinical information, imaging, and laboratory tests, as well as treatment and prognostic characteristics. Descriptive statistical analysis was applicated. Results: Of the 21 cases with AESD, 11 were males and 10 were females, with the age of onset of 2 years and 6 months (1 year and 7 months, 3 years and 6 months). Of the 21 cases, 18 were typical cases with biphasic seizures. All typical cases had early seizures within 24 hours before or after fever onset. Among them, 16 cases had generalized seizures, 2 cases had focal seizures, and 7 cases reached the status epilepticus. Of the 21 cases, 3 atypical cases had late seizures in biphasic only. The late seizures in the 21 cases occurred on days 3 to 9. The types of late seizures included focal seizures in 12 cases, generalized seizures in 6 cases, and both focal and generalized seizures in 3 cases. Diffusion-weighted imaging (DWI) test on days 3 to 11 showed reduced diffusion of subcortical white matter which was named "bright tree sign" in all cases. The diffuse cerebral atrophy predominantly presented in the front-parietal-temporal lobes was found in 19 cases between day 12 and 3 months after the onset of the disease. Among 21 cases, 20 had been misdiagnosed as autoimmune encephalitis, central nervous system infection, febrile convulsions, posterior reversible encephalopathy syndrome, acute disseminated encephalomyelitis, and hemiconvulsion-hemiplegia-epilepsy syndrome. All the cases received high-dose gammaglobulin and methylprednisolone pulse therapy with poor therapeutic effect. By July 2023, 18 cases were under follow-up. Among them, 17 cases were left with varying degrees of neurologic sequelae, including 11 cases with post-encephalopathic epilepsy; 1 recovered completely. Conclusions: AESD is characterized by biphasic seizures clinically and "bright tree sign" on DWI images. Symptomatic and supportive treatments are recommended. The immunotherapy is ineffective. The prognosis of AESD is poor, with a high incidence of neurological sequelae and a low mortality.

Elevated phospholipids and acylcarnitines C4 and C5 in cerebrospinal fluid distinguish viral CNS infections from autoimmune neuroinflammation

BackgroundViral and autoimmune encephalitis may present with similar symptoms, but require different treatments. Thus, there is a need for biomarkers to improve diagnosis and understanding of pathogenesis. We hypothesized that virus-host cell interactions lead to different changes in central nervous system (CNS) metabolism than autoimmune processes and searched for metabolite biomarkers in cerebrospinal fluid (CSF) to distinguish between the two conditions.MethodsWe applied a targeted metabolomic/lipidomic analysis to CSF samples from patients with viral CNS infections (n = 34; due to herpes simplex virus [n = 9], varicella zoster virus [n = 15], enteroviruses [n = 10]), autoimmune neuroinflammation (n = 25; autoimmune anti-NMDA-receptor encephalitis [n = 8], multiple sclerosis [n = 17), and non-inflamed controls (n = 31; Gilles de la Tourette syndrome [n = 20], Bell’s palsy with normal CSF cell count [n = 11]). 85 metabolites passed quality screening and were evaluated as biomarkers. Standard diagnostic CSF parameters were assessed for comparison.ResultsOf the standard CSF parameters, the best biomarkers were: CSF cell count for viral infections vs. controls (area under the ROC curve, AUC = 0.93), Q-albumin for viral infections vs. autoimmune neuroinflammation (AUC = 0.86), and IgG index for autoimmune neuroinflammation vs. controls (AUC = 0.90). Concentrations of 2 metabolites differed significantly (p < 0.05) between autoimmune neuroinflammation and controls, with proline being the best biomarker (AUC = 0.77). In contrast, concentrations of 67 metabolites were significantly higher in viral infections than controls, with SM.C16.0 being the best biomarker (AUC = 0.94). Concentrations of 68 metabolites were significantly higher in viral infections than in autoimmune neuroinflammation, and the 10 most accurate metabolite biomarkers (AUC = 0.89–0.93) were substantially better than Q-albumin (AUC = 0.86). These biomarkers comprised six phosphatidylcholines (AUC = 0.89–0.92), two sphingomyelins (AUC = 0.89, 0.91), and acylcarnitines isobutyrylcarnitine (C4, AUC = 0.92) and isovalerylcarnitine (C5, AUC = 0.93). Elevated C4 and C5 concentrations suggested dysfunctional mitochondrial β-oxidation and correlated only moderately with CSF cell count (Spearman ρ = 0.41 and 0.44), indicating that their increase is not primarily driven by inflammation.ConclusionsChanges in CNS metabolism differ substantially between viral CNS infections and autoimmune neuroinflammation and reveal CSF metabolites as pathophysiologically relevant diagnostic biomarkers for the differentiation between the two conditions. In viral CNS infections, the observed higher concentrations of free phospholipids are consistent with disruption of host cell membranes, whereas the elevated short-chain acylcarnitines likely reflect compromised mitochondrial homeostasis and energy generation.

Loss to Hospital Follow-Up in Pediatric Cerebral Malaria Survivors: A Case-Control Study.

Children surviving central nervous system (CNS) infections are at high risk of neurological, behavioral, and cognitive sequalae. Early identification, characterization, and treatment of these sequelae may improve child and family health. In Africa, it is unclear if there are demographic or clinical factors that increase the risk of post-hospital loss to follow-up in children with CNS infections. If these factors exist, targeted educational efforts to increase rates of post-hospital retention could be focused on families at highest risk. We performed a case-control study of Malawian children with cerebral malaria, a locally common CNS infection, previously admitted to a specialized research unit in Blantyre, Malawi. Routine survivor post-hospital follow-up was scheduled for 1 month, 6 months, and 12 months. We compared demographic and clinical characteristics between 84 children who missed one or more of these post-hospital visits with 120 children who attended all visits. There were no statistically significant differences in demographic or clinical characteristics between children whose families returned for all follow-up visits and those who did not. Specifically, when comparing these groups, we found no differences in age (P = 00.646), sex (P = 0.789), duration of hospitalization (P = 0.903), distance from home to hospital (P = 0.355), type or severity of neurological sequelae (P = 0.837), guardian literacy (P = 0.057), or number of discharge medications (P = 0.464). No factors assessed in this study were associated with higher risk of loss to follow-up in Malawian child survivors of CNS infections. During hospitalization, educational efforts to increase post-hospital retention should focus on all families.