Clinical trial links oncolytic immunoactivation to survival in glioblastoma.

Immunotherapy failures can result from the highly suppressive tumour microenvironment that characterizes aggressive forms of cancer such as recurrent glioblastoma (rGBM)1,2. Here we report the results of a first-in-human phase I trial in 41 patients with rGBM who were injected with CAN-3110-an oncolytic herpes virus (oHSV)3. In contrast to other clinical oHSVs, CAN-3110 retains the viral neurovirulence ICP34.5 gene transcribed by a nestin promoter; nestin is overexpressed in GBM and other invasive tumours, but not in the adult brain or healthy differentiated tissue4. These modifications confer CAN-3110 with preferential tumour replication. No dose-limiting toxicities were encountered. Positive HSV1 serology was significantly associated with both improved survival and clearance of CAN-3110 from injected tumours. Survival after treatment, particularly in individuals seropositive for HSV1, was significantly associated with (1) changes in tumour/PBMC T cell counts and clonal diversity, (2) peripheral expansion/contraction of specific T cell clonotypes; and (3) tumour transcriptomic signatures of immune activation. These results provide human validation that intralesional oHSV treatment enhances anticancer immune responses even in immunosuppressive tumour microenvironments, particularly in individuals with cognate serology to the injected virus. This provides a biological rationale for use of this oncolytic modality in cancers that are otherwise unresponsive to immunotherapy (ClinicalTrials.gov: NCT03152318 ).

Mimics of Pediatric Small Vessel Primary Angiitis of the Central Nervous System.

OBJECTIVE: Small vessel primary angiitis of the central nervous system is a rare and often severe disease characterized by central nervous system-restricted inflammatory vasculitis on histopathology. Diagnosis requires brain biopsy for confirmation and is suggested prior to starting immunotherapy when feasible. However, emerging evidence suggests that other neuroinflammatory conditions may have a clinical and radiographic phenotype that mimics small vessel primary angiitis, at times with overlapping pathologic features as well. Such diagnoses, including myelin oligodendrocyte glycoprotein antibody-associated disease and central nervous system-restricted hemophagocytic lymphohistiocytosis, can be non-invasively diagnosed with serum antibody or genetic testing that would prompt different monitoring and treatment paradigms. To determine the ultimate diagnosis of patients who were suspected prior to biopsy to have small vessel primary angiitis, we reviewed the clinical, radiographic, and pathological features of a cohort of patients at a single center undergoing brain biopsy for non-oncologic indications. METHODS: Clinical data were retrospectively extracted from the medical record. Pathology and neuroimaging review was conducted. RESULTS: We identified 21 patients over a 19-year time-period, of whom 14 (66.7%) were ultimately diagnosed with entities other than small vessel primary angiitis that would have obviated the need for brain biopsy. Diagnoses included anti-myelin oligodendrocyte glycoprotein antibody associated disease (n = 9), central nervous system-restricted hemophagocytic lymphohistiocytosis (n = 3), anti-GABAA receptor encephalitis (n = 1), and Aicardi-Goutières syndrome (n = 1). INTERPRETATION: This study highlights the importance of pursuing now readily available non-invasive testing for mimicking diagnoses before performing a brain biopsy for suspected small vessel primary angiitis of the central nervous system. ANN NEUROL 2023;93:109-119.

Teaching Infectious Disease Pathology and Taking it To Africa.

With the advent of increasing emerging infectious diseases, rising antibiotic resistance, and the growing number of immunocompromised patients, there is increasing demand for infectious disease (ID) pathology expertise and microbiology testing. Currently, ID pathology training and emerging molecular microbiology techniques (eg, metagenomic next-generation sequencing and whole genome sequencing) are not included in the most American Council of Graduate Medical Education medical microbiology fellowship curricula, and not surprisingly, many institutions lack anatomical pathologists with expertise in ID pathology and advanced molecular diagnostics. In this article, we describe the curriculum and structure of the Franz von Lichtenberg Fellowship in Infectious Disease and Molecular Microbiology at Brigham and Women's Hospital in Boston, MA. We emphasize the value of a training model that strives to integrate anatomical pathology, clinical pathology, and molecular pathology by providing examples in a case-based format and presenting selected metrics of the potential effect of such integrative ID pathology service and briefly describing opportunities and challenges of our global health efforts in Rwanda.

What Can We Still Learn from Brain Autopsies in COVID-19?

Neuropathological findings have been published from ∼900 patients who died with or from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, representing less than 0.01% of the close to 6.4 million deaths reported to the World Health Organization 2 years into the coronavirus disease 2019 (COVID-19) pandemic. In this review, we extend our prior work summarizing COVID-19 neuropathology by including information on published autopsies up to June 2022, and neuropathological studies in children, COVID-19 variants, secondary brain infections, ex vivo brain imaging, and autopsies performed in countries outside of the United States or Europe. We also summarize research studies that investigate mechanisms of neuropathogenesis in nonhuman primates and other models. While a pattern of cerebrovascular pathology and microglial-predominant inflammation remains the primary COVID-19-associated neuropathological finding, there is no singular understanding of the mechanisms that underlie neurological symptoms in acute COVID-19 or the post-acute COVID-19 condition. Thus, it is paramount that we incorporate microscopic and molecular findings from brain tissue into what we know about the clinical disease so that we attain best practice guidance and direct research priorities for the study of the neurological morbidity of COVID-19.

Rigidoporus corticola Colonization and Invasive Fungal Disease in Immunocompromised Patients, United States.

We report 2 cases of Rigidoporus corticola (Oxyporus corticola) infection in humans in the United States. Clinical manifestations consisted of angioinvasive fungal sinusitis in 1 patient and pulmonary intracavitary fungus ball in the other patient. These cases illustrate previously undescribed clinicopathologic manifestations of infection by this filamentous basidiomycete in humans.

Absence of SARS-CoV-2 Spike glycoprotein expression in placentas from individuals after mRNA SARS-CoV-2 vaccination.

Current public health initiatives to contain the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) global pandemic focus on expanding vaccination efforts to include vulnerable populations such as pregnant people. Vaccines using messenger ribonucleic acid (mRNA) technology rely on translation by immune cells, primarily at the injection site. Hesitancy remains among the general population regarding the safety of mRNA vaccines during gestation, and it remains unknown whether the SARS-CoV-2 Spike protein (the product of mRNA vaccines available) accumulates in the placenta after vaccination. Objective: To determine whether Spike protein translation and accumulation occurs in placental tissue in the context of recent mRNA SARC-CoV-2 vaccination during pregnancy. We identified 48 patients receiving one or two doses of mRNA SARS-CoV-2 vaccine during gestation and used immunohistochemistry against SARS-CoV-2 Spike protein in formalin-fixed, paraffin-embedded placental tissue. One placenta, positive for SARS-CoV-2 RNA by in situ hybridization (ISH) was used as positive control. Seven term placentas collected prior to the emergence of SARS-CoV-2 served as negative controls. Eighty one percent of patients in the study group underwent third-trimester delivery; remaining had a first-trimester spontaneous abortion or elective second-trimester termination. Patients received two (52%) or one (48%) vaccine doses during pregnancy, with a median interval between latest dose and delivery of 13 days (range 2-79 days). Most (63%) cases had their latest dose within 15 days prior to delivery. All the placentas in the study and negative control groups were negative for SARS-CoV-2 immunohistochemistry. Six study cases with short vaccine-delivery intervals (2-7 days) were subjected to SARS-CoV-2 ISH and were negative. Our findings suggest that mRNA vaccines do not reach significant concentrations in the placenta given the absence of definitive SARS-CoV-2 Spike protein accumulation in placental tissue. This observation provides evidence supporting the safety of mRNA vaccines to the placental-fetal unit.

Mechanisms of Entry Into the Central Nervous System by Neuroinvasive Pathogens.

BACKGROUND: The literature on neurological manifestations, cerebrospinal fluid analyses, and autopsies in patients with COVID-19 continues to grow. The proposed mechanisms for neurological disease in patients with COVID-19 include indirect processes such as inflammation, microvascular injury, and hypoxic-ischemic damage. An alternate hypothesis suggests direct viral entry of SARS-CoV-2 into the brain and cerebrospinal fluid, given varying reports regarding isolation of viral components from these anatomical sites. EVIDENCE ACQUISITION: PubMed, Google Scholar databases, and neuroanatomical textbooks were manually searched and reviewed. RESULTS: We provide clinical concepts regarding the mechanisms of viral pathogen invasion in the central nervous system (CNS); advances in our mechanistic understanding of CNS invasion in well-known neurotropic pathogens can aid in understanding how viruses evolve strategies to enter brain parenchyma. We also present the structural components of CNS compartments that influence viral entry, focusing on hematogenous and transneuronal spread, and discuss this evidence as it relates to our understanding of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). CONCLUSIONS: Although there is a paucity of data supporting direct viral entry of SARS-CoV-2 in humans, increasing our knowledge of the structural components of CNS compartments that block viral entry and pathways exploited by pathogens is fundamental to preparing clinicians and researchers for what to expect when a novel emerging virus with neurological symptoms establishes infection in the CNS, and how to design therapeutics to mitigate such an infection.

Fatal Case of Chronic Jamestown Canyon Virus Encephalitis Diagnosed by Metagenomic Sequencing in Patient Receiving Rituximab.

A 56-year-old man receiving rituximab who had months of neurologic symptoms was found to have Jamestown Canyon virus in cerebrospinal fluid by clinical metagenomic sequencing. The patient died, and postmortem examination revealed extensive neuropathologic abnormalities. Deep sequencing enabled detailed characterization of viral genomes from the cerebrospinal fluid, cerebellum, and cerebral cortex.

In situ detection of SARS-CoV-2 in lungs and airways of patients with COVID-19.

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has led to a global public health crisis. In elderly individuals and those with comorbidities, COVID-19 is associated with high mortality, frequently caused by acute respiratory distress syndrome. We examine in situ expression of SARS-CoV-2 in airways and lung obtained at autopsy of individuals with confirmed COVID-19 infection. Seven autopsy cases (male, N = 5; female, N = 2) with reverse transcriptase-polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection and a median age of 66 years (range, 50-77 years) were evaluated using a rabbit polyclonal antibody against SARS Nucleocapsid protein in correlation with clinical parameters. The median time from symptom onset to death was 9 days (range, 6-31 days), from hospitalization 7 days (range, 1-21 days), from positive RT-PCR 7 days (range, 0-18 days), and from intensive care unit admission defining onset of respiratory failure 3 days (range, 1-18 days). Chest imaging identified diffuse airspace disease in all patients corresponding to acute and (N = 5) or organizing (N = 2) diffuse alveolar damage (DAD) on histologic examination. Among five patients with acute-phase DAD (≤7 days from onset of respiratory failure), SARS-CoV-2 was detected in pulmonary pneumocytes and ciliated airway cells (N = 5), and in upper airway epithelium (N = 2). In two patients with organizing DAD (>14 days from onset of respiratory failure), no virus was detected in lungs or airways. No endothelial cell infection was observed. The findings suggest that SARS-CoV-2 infection of epithelial cells in lungs and airways of patients with COVID-19 who developed respiratory failure can be detected during the acute phase of lung injury and is absent in the organizing phase.

Use of triazoles for the treatment of invasive aspergillosis: A three-year cohort analysis.

In a 3-year cohort study of adult patients with proven or probable IA, fewer patients initially treated with isavuconazole experienced adverse events compared with voriconazole, but more patients required a change in therapy due to lack of clinical efficacy.

Learning from history: Lord Brain and Hashimoto's encephalopathy.

We present two historic cases of severe encephalopathy associated with antithyroid antibodies. The first was published by Lord Brain of Eynsham, and the second was from our department's archives. Although both cases are from archival sources, they continue to inform current clinical care. We briefly review the poorly defined entity, Hashimoto's encephalopathy, and discuss diagnostic advances for autoimmune encephalopathy and for Creutzfeldt-Jakob disease. We advocate for giving a trial of corticosteroids to patients with 'encephalopathy, not otherwise specified' while awaiting antibody results or more definitive testing. Our case, initially diagnosed as having Creutzfeldt-Jakob disease, responded remarkably (with video evidence) to a trial of corticosteroids.

Frozen sections are unreliable for the diagnosis of necrotizing soft tissue infections.

Necrotizing soft tissue infections are rare but are associated with high rates of morbidity and mortality. The use of bedside or intraoperative frozen sections has been reported to be associated with faster diagnosis and better outcomes; however, to date no large studies have been published to determine the sensitivity and specificity of frozen sections in this setting. Twenty years of cases suspicious for necrotizing soft tissue infection at a large academic referral center were reviewed, blinded to the final clinical diagnosis (gold standard). Cases were assessed for the number of neutrophils, extent of necrosis, presence of thrombi, bacteria, karyorrhexis, and fibrin, and concordance with permanent sections. A total of 166 cases suspicious for necrotizing soft tissue infection had frozen section slides available for review. Sixty-three cases were clinically determined to be positive and 103 negative. Neutrophils, necrosis, thrombi, bacteria, karyorrhexis, and fibrin were present in both positive and negative cases; however, no histological feature or combination of features was found to be both sensitive and specific for necrotizing soft tissue infection. The combined presence of necrosis and frequent neutrophils was 73% sensitive and 68% specific, with a 58% positive predictive value and 80% negative predictive value. The additional observation of bacteria decreased sensitivity to 32%, whereas raising specificity to 91%, with 69% positive predictive value and 68% negative predictive value. Thirty-two cases (19%) contained findings identified on permanent sections (eg, bacteria) not observed on frozen section slides, highlighting the risk of false negatives owing to technical limitations or sampling errors. Frozen sections in necrotizing soft tissue infections and negative cases may show similar histological findings. Combined with the risk of false negatives, these results suggest that frozen sections are likely to be of limited clinical utility due to lack of sensitivity and specificity, and risk for delayed diagnosis and treatment.

Immunophenotyping of pediatric brain tumors: correlating immune infiltrate with histology, mutational load, and survival and assessing clonal T cell response.

There is little known regarding the immune infiltrate present in pediatric brain tumors and how this compares to what is known about histologically similar adult tumors and its correlation with survival. Here, we provide a descriptive analysis of the immune infiltrate of 22 fresh pediatric brain tumor tissue samples of mixed diagnoses and 40 peripheral blood samples. Samples were analyzed using a flow cytometry panel containing markers for immune cell subtypes, costimulatory markers, inhibitory signals, and markers of activation. This was compared to the standard method of immunohistochemistry (IHC) for immune markers for 89 primary pediatric brain tumors. Both flow cytometry and IHC data did not correlate with the grade of tumor or mutational load and IHC data was not significantly associated with survival for either low grade or high grade gliomas. There is a trend towards a more immunosuppressive phenotype in higher grade tumors with more regulatory T cells present in these tumor types. Both PD1 and PDL1 were present in only a small percentage of the tumor infiltrate. T cell receptor sequencing revealed up to 10% clonality of T cells in tumor infiltrates and no significant difference in clonality between low and high grade gliomas. We have shown the immune infiltrate of pediatric brain tumors does not appear to correlate with grade or survival for a small sample of patients. Further research and larger studies are needed to fully understand the interaction of pediatric brain tumors and the immune system.

Histopathology of vaccine-preventable diseases.

The widespread use of vaccines has been one of the most important medical advances in the last century, saving trillions of dollars and millions of lives. Despite local eradication of some infections, travellers returning from affected areas may cause outbreaks through reintroduction of pathogens to individuals who are unable to receive vaccines for medical reasons or who have declined vaccination for non-medical reasons. Infections that would otherwise be uncommonly encountered by anatomical pathologists should therefore remain in the differential diagnosis for immunocompromised and unvaccinated patients. We review here the histopathological features and ancillary testing required for diagnosis of all illnesses preventable by vaccines that are currently approved for use by the United States Food and Drug Administration, organized into three sections: viral infections preventable by routine vaccination (measles, mumps, rubella, varicella, rotavirus, polio, hepatitis A, hepatitis B, influenza, and human papillomavirus), bacterial infections preventable by routine vaccination (diptheria, tetanus, pertussis, Haemophilus influenzae, pneumococcus, and meningococcus), and infections with specific vaccine indications (anthrax, typhoid, tuberculosis, rabies, Japanese encephalitis, yellow fever, smallpox, and adenovirus). Histopathology for the less common diseases is illustrated in this review. Awareness of a patient's immune and/or vaccine status is a crucial component of the infectious disease work-up, especially for rare diseases that may not otherwise be seen.

Brain and liver pathology, amyloid deposition, and interferon responses among older HIV-positive patients in the late HAART era.

BACKGROUND: HIV+ patients on highly active antiretroviral therapy (HAART) with suppressed viral loads have a low incidence of HIV-associated dementia, but increased prevalence of milder forms of HIV-associated neurocognitive disorders (HAND). These milder forms of HAND are often associated with minimal histological abnormalities, and their pathophysiology is unclear. Comorbidities, altered amyloid metabolism, accelerated brain aging, and activated interferon responses are suspected to play a role in HAND pathogenesis in HAART-treated persons. METHODS: To investigate associations between liver disease, accelerated brain aging, and HAND in HIV+ patients in the late HAART era (2002-2015), we studied liver and brain autopsy tissues from 53 older subjects evaluated at UCLA and BWH using histopathological stains, a sensitive fluorescent amyloid stain (AmyloGlo), and targeted gene expression profiling (NanoString). RESULTS: The majority of HIV+ subjects (median age 56) were on HAART (89.3%) with last pre-mortem plasma viral load <400 copies/mL (81.5%); 50% had CD4+ counts <200 cells/µL. Compared to HIV- controls (median age 65), HIV+ subjects had more cancer (p = 0.04), illicit drug use (p <0.00001), and HCV co-infection (p = 0.002), less cardiovascular disease (p = 0.03), and similar prevalence of cerebrovascular disease (~40%), hypertension, hyperlipidemia, and diabetes. Deep frontal white matter showed increased gliosis in HIV+ subjects vs. HIV- controls (p = 0.09), but no significant differences in myelin loss, blood vessel thickening, or inflammation. Liver showed more severe fibrosis/cirrhosis (p = 0.02) and less steatosis (p = 0.03) in HIV+ subjects, but no significant differences in inflammation, blood vessel thickness, or pigment deposition. There were no significant associations between liver and brain pathologies. AmyloGlo staining detected large amyloid deposits in only one HIV+ case (age 69 with Alzheimer's disease pathology) and two HIV- controls (ages 66 and 74). White matter from HIV+ cases vs. HIV- seronegative controls showed a trend (p = 0.06) towards increased interferon response gene expression (ISG15, MX1, IFIT1, IFIT2, and IFITM1). CONCLUSIONS: Gliosis and cerebrovascular disease, but not accelerated amyloid deposition, are common brain pathologies among older HIV+ patients in the late HAART era. Although HIV+ subjects had more cirrhosis, liver pathology was not associated with any consistent pattern of brain pathology. Cerebrovascular disease, interferon responses, and neuroinflammation are likely factors contributing to brain aging and HAND in older HIV+ patients on current HAART regimens.

Rapid-Growing Mycobacteria Infections in Medical Tourists: Our Experience and Literature Review.

BACKGROUND: "Medical tourism" has gained popularity over the past few decades. This is particularly common with patients seeking elective cosmetic surgery in the developing world. However, the risk of severe and unusual infectious complications appears to be higher than for patients undergoing similar procedures in the United States. OBJECTIVES: The authors describe their experience with atypical mycobacterial infections in cosmetic surgical patients returning to the United States postoperatively. METHODS: A review of patient medical records presenting with infectious complications after cosmetic surgery between January 2010 and July 2015 was performed. Patients presenting with mycobacterial infections following cosmetic surgery were reviewed in detail. An extensive literature review was performed for rapid-growing mycobacteria (RGM) related to cosmetic procedures. RESULTS: Between January 2010 and July 2015, three patients presented to our institution with culture-proven Mycobacterium abscessus at the sites of recent cosmetic surgery. All had surgery performed in the developing world. The mean age of these patients was 36 years (range, 29-44 years). There was a delay of up to 16 weeks between the initial presentation and correct diagnosis. All patients were treated with surgical drainage and combination antibiotics with complete resolution. CONCLUSIONS: We present series of patients with mycobacterial infections after cosmetic surgery in the developing world. This may be related to the endemic nature of these bacteria and/or inadequate sterilization or sterile technique. Due to low domestic incidence of these infections, diagnosis may be difficult and/or delayed. Consulting physicians should have a low threshold to consider atypical etiologies in such scenarios. LEVEL OF EVIDENCE: 5 Therapeutic.