Short Course Training on a Quality Management System for Pathologists, Trainees, and Histotechnologists During the African Pathology Assembly

OBJECTIVES

Provide quality management training in anatomic pathology so that slides are of adequate quality and can be interpreted.

METHODS

During the first African Pathology Assembly, we performed a needs assessment and knowledge quizzes, then presented 4 modules of the quality management system (personnel management, process control, sample management, and equipment) that are used to train quality in vertical programs by the World Health Organization.

RESULTS

Participants included 14 (34%) trainees, 14 (34%) pathologists, and 9 (22%) technologists from South Africa (11), Nigeria (6), Tanzania (4), and other countries (18). Thirty (73%) participants took the course because they had interest in the topic while 6 (15%) did it because it was recommended by a supervisor. Most participants thought that the quality of slides was medium to high in their institution and that clinicians trust results. The most frequent quality issues cited included problems from processing to staining, long turnaround times, and preanalytical issues (fixation, lack of clinical history). The average result of the knowledge quiz was 6.7 (range, 2-10) before (38 participants) the course and 8.3 (range, 5-10) after (30 participants) the course.

CONCLUSIONS

This assessment suggests there is a need for quality management courses in pathology in Africa.

Survey of blood collection and transfusion practices among institutions in Africa

INTRODUCTION

Dramatic improvements in blood transfusion have occurred during the last two decades. Transfusion medicine services and practices in Africa remain underexplored.

METHODS

A survey of blood bank/transfusion medicine (BBTM) practices, available blood products, blood product source(s), pre-transfusion testing, and blood donor infectious disease testing methodologies across Africa was performed using the American Society for Clinical Pathology (ASCP) listserv. Survey recipients included hospital-based laboratories/blood banks, national transfusion medicine services, and free-standing laboratories (collectively referred to as institutions).

RESULTS

Responses from a total of 81 institutions across 22 countries were analyzed. All 81 institutions provide at least one type of blood product-whole blood, red blood cells (RBCs), platelets, plasma, and cryoprecipitate, with whole blood (90.1%, 73 of 81) and RBCs (79.0%, 64 of 81) most common, while cryoprecipitate is least common (12.4%, 10 of 81). Only five countries had a responding institution that provides all types of products. Among institutions that collect blood onsite, the most common sources of blood products are patients' family members (94.1%, 48 of 51) and pre-screened on-demand volunteer donors (82.4%, 42 of 51). The most commonly screened infectious agents are HIV and hepatitis B virus (both 81.5%), while 70.4% (57 of 81) test for hepatitis C virus (HCV) and Treponema pallidum.

DISCUSSION

This study highlights significant variability and restrictions in blood product availability, pre-transfusion testing, and blood donor infectious disease testing across Africa. Further studies are needed to ascertain barriers to improving blood donor availability, blood product safety, and infectious disease testing.

Analysis of Cancer Research Projects in Sub-Saharan Africa: A Quantitative Perspective on Unmet Needs and Opportunities

PURPOSE

To evaluate the scope and types of cancer research projects in sub-Saharan Africa (SSA) to identify research gaps and inform future efforts.

METHODS

This retrospective observational study summarized information on cancer research projects in SSA from the International Cancer Research Partnership (ICRP) between 2015 and 2020, alongside 2020 cancer incidence and mortality data from the Global Cancer Observatory. SSA cancer research projects were identified as led by investigators in SSA countries, or by investigators in non-SSA countries with collaborators in SSA, or in database keyword searches. Projects from the Coalition for Implementation Research in Global Oncology (CIRGO) were also summarized.

RESULTS

A total of 1,846 projects were identified from the ICRP database, funded by 34 organizations in seven countries (only one, Cancer Association of South Africa, based in SSA); only 156 (8%) were led by SSA-based investigators. Most projects focused on virally induced cancers (57%). Across all cancer types, projects were most frequently related to cervical cancer (24%), Kaposi sarcoma (15%), breast cancer (10%), or non-Hodgkin lymphoma (10%). Gaps were observed for several cancers with higher incidence/mortality burden in SSA; for example, prostate cancer accounted for only 4% of projects but 8% of cancer-related deaths and 10% of new cases. Approximately 26% were dedicated to etiology. Treatment-related research declined over the study period (14%-7% of all projects), while projects related to prevention (15%-20%) and diagnosis/prognosis (15%-29%) increased. Fifteen CIRGO projects were identified; seven were relevant across multiple cancer types, and 12 focused either wholly or partially on cancer control (representing 50% of the total research effort).

CONCLUSION

This analysis shows notable discrepancies between cancer burden and research projects and identifies opportunities for future strategic investments in cancer care in SSA.

Validating Whole Slide Imaging Systems for Diagnostic Purposes in Pathology

CONTEXT.—

The original guideline, "Validating Whole Slide Imaging for Diagnostic Purposes in Pathology," was published in 2013 and included 12 guideline statements. The College of American Pathologists convened an expert panel to update the guideline following standards established by the National Academies of Medicine for developing trustworthy clinical practice guidelines.

OBJECTIVE.—

To assess evidence published since the release of the original guideline and provide updated recommendations for validating whole slide imaging (WSI) systems used for diagnostic purposes.

DESIGN.—

An expert panel performed a systematic review of the literature. Frozen sections, anatomic pathology specimens (biopsies, curettings, and resections), and hematopathology cases were included. Cytology cases were excluded. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, the panel reassessed and updated the original guideline recommendations.

RESULTS.—

Three strong recommendations and 9 good practice statements are offered to assist laboratories with validating WSI digital pathology systems.

CONCLUSIONS.—

Systematic review of literature following release of the 2013 guideline reaffirms the use of a validation set of at least 60 cases, establishing intraobserver diagnostic concordance between WSI and glass slides and the use of a 2-week washout period between modalities. Although all discordances between WSI and glass slide diagnoses discovered during validation need to be reconciled, laboratories should be particularly concerned if their overall WSI-glass slide concordance is less than 95%.

Epstein-Barr virus prevalence among subtypes of malignant lymphoma in Rwanda, 2012 to 2018

Few data exist on Epstein-Barr virus (EBV) prevalence across the full spectrum of lymphoma subtypes, particularly in sub-Saharan Africa. The objective of our study was to test the presence of EBV in a nationally representative sample of malignant lymphomas diagnosed in the Butaro Cancer Center of Excellence (BCCOE) in Rwanda. Of 102 Hodgkin (HL) and 378 non-Hodgkin lymphomas (NHL) diagnosed in BCCOE between 2012 and 2018, 52 HL and 207 NHL were successfully tested by EBV-encoding RNA in situ hybridization. EBV prevalence was 54% in HL, being detected in all classical HL subtypes: mixed-cellularity (n = 3/8), nodular-sclerosis (n = 7/17) and lymphocyte-rich (n = 2/3). EBV prevalence was 9% in NHL, being 10% among 158 B-cell NHL, 3% among 35 T-cell NHL and the single NK-cell NHL was EBV-positive. Among B-cell NHL, EBV was present in the majority of Burkitt (n = 8/13), and was also rarely detected in follicular (n = 1/4) and acute B-cell lymphoblastic (n = 1/45) lymphomas. Five of the 45 (11%) diffuse large B-cell lymphomas (DLBCLs) were EBV-positive, including three out of five plasmablastic lymphoma (PBL). Of 39 HL and 163 NHL of known human immunodeficiency virus (HIV) status, 2 (5%) and 14 (9%) were HIV-positive, respectively, of which only four were also EBV-positive (2 PBL, 2 HL). In summary, we report rare regional-level data on the association of EBV with classical HL, Burkitt and DLBCLs, and report sporadic detection in other subtypes possibly related to EBV. Such data inform the burden of disease caused by EBV and can help guide application of future advances in EBV-specific prevention and therapeutics.

International perspectives on the development, application, and evaluation of a multicancer early detection strategy

The development and implementation of a multicancer early detection (MCED) test that is effective and affordable has the potential to change cancer care systems around the world. However, careful consideration is needed within the context of different health care settings (both low- and middle-income countries and high-income countries) to roll out an MCED test and promote equity in access.

Can pathology diagnostic services for cancer be stratified and serve global health?

BACKGROUND

Before initiating cancer therapy, a diagnostic tumor tissue sample evaluated within a pathology laboratory by a pathologist is essential to confirm the malignancy type and provide key prognostic factors that direct the treatment offered.

METHODS

Pathology evaluation includes multiple expensive reagents, complex equipment, and both laboratory and pathologist technical skills. By using breast cancer as an example, at a minimum, key tumor prognostic information required before the initiation of treatment includes subtype, tumor grade, tumor size, lymph node status when possible, and biomarker expression determined by immunohistochemistry for estrogen receptor. The additional determination of biomarker expression of progesterone receptor and human epidermal growth factor receptor (HER2) is the standard of care in high-resource settings, but assays may not be affordable in low-income and middle-income countries.

RESULTS

With positive tests, patients are eligible for either tamoxifen (for estrogen receptor-positive/progesterone receptor-positive cancers) or monoclonal antibody therapy (for HER2-positive cancers). For settings in which endocrine therapy and/or HER2-targeted therapy is unavailable, biomarker studies have no utility, and high-resource setting standards for pathology evaluation and reporting are unachievable. Resource-stratified pathology evaluation guidelines in cancer diagnosis have not been developed, in contrast to excellent comprehensive, resource-stratified clinical guidelines for use in low-income and middle-income countries, and these are long overdue.

CONCLUSIONS

The challenges of pathology evaluation in the context of global health are being met by innovative solutions, which may change the face of pathology practice.

Adipose tissue parasite sequestration drives leptin production in mice and correlates with human cerebral malaria

Circulating levels of the adipokine leptin are linked to neuropathology in experimental cerebral malaria (ECM), but its source and regulation mechanism remain unknown. Here, we show that sequestration of infected red blood cells (iRBCs) in white adipose tissue (WAT) microvasculature increased local vascular permeability and leptin production. Mice infected with parasite strains that fail to sequester in WAT displayed reduced leptin production and protection from ECM. WAT sequestration and leptin induction were lost in CD36KO mice; however, ECM susceptibility revealed sexual dimorphism. Adipocyte leptin was regulated by the mechanistic target of rapamycin complex 1 (mTORC1) and blocked by rapamycin. In humans, although Plasmodium falciparum infection did not increase circulating leptin levels, iRBC sequestration, tissue leptin production, and mTORC1 activity were positively correlated with CM in pediatric postmortem WAT. These data identify WAT sequestration as a trigger for leptin production with potential implications for pathogenesis of malaria infection, prognosis, and treatment.

Statistical Methods in Experimental Pathology: A Review and Primer

Correct use of statistical methods is important to ensure the reliability and value of the published experimental pathology literature. Considering increasing interest in the quality of statistical reporting in pathology, the statistical methods used in 10 recent issues of the American Journal of Pathology were reviewed. The statistical tests performed in the articles were summarized, with attention to their implications for contemporary pathology research and practice. Among the 195 articles identified, 93% reported using one or more statistical tests. Retrospective statistical review of the articles revealed several key findings. First, tests for normality were infrequently reported, and parametric hypothesis tests were overutilized. Second, studies reporting multisample hypothesis tests (eg, analysis of variance) infrequently performed post hoc tests to explore differences between study groups. Third, correlation, regression, and survival analysis techniques were underutilized. On the basis of these findings, a primer on relevant statistical concepts and tests is presented, including issues related to optimal study design, descriptive and comparative statistics, and regression, correlation, survival, and genetic data analysis.

Biomarkers to distinguish bacterial from viral pediatric clinical pneumonia in a malaria endemic setting

Background

Differential etiologies of pediatric acute febrile respiratory illness pose challenges for all populations globally, but especially in malaria-endemic settings because the pathogens responsible overlap in clinical presentation and frequently occur together. Rapid identification of bacterial pneumonia with high-quality diagnostic tools would enable appropriate, point-of-care antibiotic treatment. Current diagnostics are insufficient, and the discovery and development of new tools is needed. We report a unique biomarker signature identified in blood samples to accomplish this.

Methods

Blood samples from 195 pediatric Mozambican patients with clinical pneumonia were analyzed with an aptamer-based, high-dynamic-range, quantitative assay (~1200 proteins). We identified new biomarkers using a training set of samples from patients with established bacterial, viral, or malarial pneumonia. Proteins with significantly variable abundance across etiologies (false discovery rate <0.01) formed the basis for predictive diagnostic models derived from machine learning techniques (Random Forest, Elastic Net). Validation on a dedicated test set of samples was performed.

Results

Significantly different abundances between bacterial and viral infections (219 proteins) and bacterial infections and mixed (viral and malaria) infections (151 proteins) were found. Predictive models achieved >90% sensitivity and >80% specificity, regardless of number of pathogen classes. Bacterial pneumonia was strongly associated with neutrophil markers—in particular, degranulation including HP, LCN2, LTF, MPO, MMP8, PGLYRP1, RETN, SERPINA1, S100A9, and SLPI.

Conclusions

Blood protein signatures highly associated with neutrophil biology reliably differentiated bacterial pneumonia from other causes. With appropriate technology, these markers could provide the basis for a rapid diagnostic for field-based triage for antibiotic treatment of pediatric pneumonia.

New Insights into Malaria Pathogenesis

Malaria remains a major public health threat in tropical and subtropical regions across the world. Even though less than 1% of malaria infections are fatal, this leads to about 430,000 deaths per year, predominantly in young children in sub-Saharan Africa. Therefore, it is imperative to understand why a subset of infected individuals develop severe syndromes and some of them die and what differentiates these cases from the majority that recovers. Here, we discuss progress made during the past decade in our understanding of malaria pathogenesis, focusing on the major human parasite Plasmodium falciparum.

Comparison of CD8+ T Cell Accumulation in the Brain During Human and Murine Cerebral Malaria

CD8⁺ T cells have been shown to play a critical role in the pathogenesis of experimental cerebral malaria (ECM) in mice, but their role in development of human cerebral malaria (HCM) remains unclear. Thus, in this study we have provided the first direct contrast of the accumulation of CD8⁺ T cells in the brain during HCM and ECM. HCM cases were from children who died of Plasmodium falciparum cerebral malaria at Queen Elizabeth Central Hospital (Malawi) between 2003 and 2010. ECM was induced by infecting C57BL/6J mice with P. berghei ANKA. We demonstrate similarities in the intracerebral CD8⁺ T cell responses in ECM and HCM, in particular an apparent shared choroid plexus-meningeal route of CD8⁺ T cell accumulation in the brain. Nevertheless, we also reveal some potentially important differences in compartmentalization of CD8⁺ T cells within the cerebrovascular bed in HCM and ECM.

Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary field that addresses heterogeneous effects of exogenous and endogenous factors (collectively termed 'exposures'), including microorganisms, on disease occurrence and consequences, utilising molecular pathological signatures of the disease. In parallel with the paradigm of precision medicine, findings from MPE research can provide aetiological insights into tailored strategies of disease prevention and treatment. Due to the availability of molecular pathological tests on tumours, the MPE approach has been utilised predominantly in research on cancers including breast, lung, prostate, and colorectal carcinomas. Mounting evidence indicates that the microbiome (inclusive of viruses, bacteria, fungi, and parasites) plays an important role in a variety of human diseases including neoplasms. An alteration of the microbiome may be not only a cause of neoplasia but also an informative biomarker that indicates or mediates the association of an epidemiological exposure with health conditions and outcomes. To adequately educate and train investigators in this emerging area, we herein propose the integration of microbiology into the MPE model (termed 'microbiology-MPE'), which could improve our understanding of the complex interactions of environment, tumour cells, the immune system, and microbes in the tumour microenvironment during the carcinogenic process. Using this approach, we can examine how lifestyle factors, dietary patterns, medications, environmental exposures, and germline genetics influence cancer development and progression through impacting the microbial communities in the human body. Further integration of other disciplines (e.g. pharmacology, immunology, nutrition) into microbiology-MPE would expand this developing research frontier. With the advent of high-throughput next-generation sequencing technologies, researchers now have increasing access to large-scale metagenomics as well as other omics data (e.g. genomics, epigenomics, proteomics, and metabolomics) in population-based research. The integrative field of microbiology-MPE will open new opportunities for personalised medicine and public health. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Insights into Pathogenic Interactions Among Environment, Host, and Tumor at the Crossroads of Molecular Pathology and Epidemiology

Evidence indicates that diet, nutrition, lifestyle, the environment, the microbiome, and other exogenous factors have pathogenic roles and also influence the genome, epigenome, transcriptome, proteome, and metabolome of tumor and nonneoplastic cells, including immune cells. With the need for big-data research, pathology must transform to integrate data science fields, including epidemiology, biostatistics, and bioinformatics. The research framework of molecular pathological epidemiology (MPE) demonstrates the strengths of such an interdisciplinary integration, having been used to study breast, lung, prostate, and colorectal cancers. The MPE research paradigm not only can provide novel insights into interactions among environment, tumor, and host but also opens new research frontiers. New developments-such as computational digital pathology, systems biology, artificial intelligence, and in vivo pathology technologies-will further transform pathology and MPE. Although it is necessary to address the rarity of transdisciplinary education and training programs, MPE provides an exemplary model of integrative scientific approaches and contributes to advancements in precision medicine, therapy, and prevention.

City Cancer Challenge: Changing the Future of Cancer in Urban Populations

Incidence and mortality from cancer is increasing in most countries in the world, with the highest burden in developing countries. City Cancer Challenge (C/Can), an initiative launched in 2017, aims to improve access to quality cancer care in metropolitan areas (1 million inhabitants or more) in low- and upper-middle income countries by transforming the way stakeholders at the city, regional, and national levels collectively design, plan, and implement local cancer solutions. The approach is built on the core principle that local leaders in cities define their own needs and craft solutions with the support of a network of global, regional, and local partners that reflect an understanding of the unique local context. C/Can aims to build a collective movement of cities that can together deliver quality, equitable, and sustainable cancer control solutions for all.

Integrative analysis of exogenous, endogenous, tumour and immune factors for precision medicine

Immunotherapy strategies targeting immune checkpoints such as the CTLA4 and CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) T-cell coreceptor pathways are revolutionising oncology. The approval of pembrolizumab use for solid tumours with high-level microsatellite instability or mismatch repair deficiency by the US Food and Drug Administration highlights promise of precision immuno-oncology. However, despite evidence indicating influences of exogenous and endogenous factors such as diet, nutrients, alcohol, smoking, obesity, lifestyle, environmental exposures and microbiome on tumour-immune interactions, integrative analyses of those factors and immunity lag behind. Immune cell analyses in the tumour microenvironment have not adequately been integrated into large-scale studies. Addressing this gap, the transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to integrate tumour immunology into population health sciences, and link the exposures and germline genetics (eg, HLA genotypes) to tumour and immune characteristics. Multilevel research using bioinformatics, in vivo pathology and omics (genomics, epigenomics, transcriptomics, proteomics and metabolomics) technologies is possible with use of tissue, peripheral blood circulating cells, cell-free plasma, stool, sputum, urine and other body fluids. This immunology-MPE model can synergise with experimental immunology, microbiology and systems biology. GI neoplasms represent exemplary diseases for the immunology-MPE model, given rich microbiota and immune tissues of intestines, and the well-established carcinogenic role of intestinal inflammation. Proof-of-principle studies on colorectal cancer provided insights into immunomodulating effects of aspirin, vitamin D, inflammatory diets and omega-3 polyunsaturated fatty acids. The integrated immunology-MPE model can contribute to better understanding of environment-tumour-immune interactions, and effective immunoprevention and immunotherapy strategies for precision medicine.

Bone Marrow Is a Major Parasite Reservoir in Plasmodium vivax Infection

Plasmodium vivax causes heavy burdens of disease across malarious regions worldwide. Mature P. vivax asexual and transmissive gametocyte stages occur in the blood circulation, and it is often assumed that accumulation/sequestration in tissues is not an important phase in their development. Here, we present a systematic study of P. vivax stage distributions in infected tissues of nonhuman primate (NHP) malaria models as well as in blood from human infections. In a comparative analysis of the transcriptomes of P. vivax and Plasmodium falciparum blood-stage parasites, we found a conserved cascade of stage-specific gene expression despite the greatly different gametocyte maturity times of these two species. Using this knowledge, we validated a set of conserved asexual- and gametocyte-stage markers both by quantitative real-time PCR and by antibody assays of peripheral blood samples from infected patients and NHP (Aotus sp.). Histological analyses of P. vivax parasites in organs of 13 infected NHP (Aotus and Saimiri species) demonstrated a major fraction of immature gametocytes in the parenchyma of the bone marrow, while asexual schizont forms were enriched to a somewhat lesser extent in this region of the bone marrow as well as in sinusoids of the liver. These findings suggest that the bone marrow is an important reservoir for gametocyte development and proliferation of malaria parasites.IMPORTANCEPlasmodium vivax malaria continues to cause major public health burdens worldwide. Yet, significant knowledge gaps in the basic biology and epidemiology of P. vivax malaria remain, largely due to limited available tools for research and diagnostics. Here, we present a systematic examination of tissue sequestration during P. vivax infection. Studies of nonhuman primates and malaria patients revealed enrichment of developing sexual stages (gametocytes) and mature replicative stages (schizonts) in the bone marrow and liver, relative to those present in peripheral blood. Identification of the bone marrow as a major P. vivax tissue reservoir has important implications for parasite diagnosis and treatment.

Measuring Success in Global Health Training: Data From 14 Years of a Postdoctoral Fellowship in Infectious Diseases and Tropical Medicine

Background.

In modern academic medicine, especially in the fields of infectious diseases and global health, aspiring physician-scientists often wait years before achieving independence as basic, translational, and clinical investigators. This study employed mixed methods to evaluate the success of the Burroughs Wellcome Fund/American Society for Tropical Medicine and Hygiene (BWF/ASTMH) global health postdoctoral fellowship in promoting scientific independence.

Methods.

We examined quantitative data obtained from the National Institutes of Health (NIH) and qualitative data provided by the ASTMH and program participants to assess BWF/ASTMH trainees' success in earning NIH grants, publishing manuscripts, and gaining faculty positions. We also calculated the return on investment (ROI) associated with the training program by dividing direct costs of NIH research grants awarded to trainees by the direct costs invested by the BWF/ASTMH fellowship.

Results.

Forty-one trainees received fellowships between 2001 and 2015. Within 3 years of completing their fellowships, 21 of 35 (60%) had received career development awards, and within 5 years, 12 of 26 (46%) had received independent research awards. Overall, 22 of 35 (63%) received 1 or more research awards. BWF/ASTMH recipients with at least 3 years of follow-up data had coauthored a mean of 36 publications (range, 2-151) and 29 of 35 (82%) held academic positions. The return on investment was 11.9 overall and 31.8 for fellowships awarded between 2001 and 2004.

Conclusions.

Between 2001 and 2015, the BWF/ASTMH postdoctoral training program successfully facilitated progress to scientific independence. This program model underscores the importance of custom-designed postdoctoral training as a bridge to NIH awards and professional autonomy.

Strengthening Laboratory Management Toward Accreditation, A Model Program for Pathology Laboratory Improvement

The Strengthening Laboratory Management Toward Accreditation (SLMTA) program and subsequent Stepwise Laboratory Quality Improvement Process Toward Accreditation (SLIPTA) checklist were a response to the need for high-quality laboratories to combat the human immunodeficiency virus (HIV) epidemic and provide patients with the highest-quality care. The two tools work together to create a culture of quality in laboratories and allow the identification of gaps. The ultimate goal for any laboratory is to achieve a standard benchmark for quality and these programs have been highly successful in initially affecting the HIV epidemic but continuously improving laboratory quality across all diseases.

1.5 Tesla Magnetic Resonance Imaging to Investigate Potential Etiologies of Brain Swelling in Pediatric Cerebral Malaria

The hallmark of pediatric cerebral malaria (CM) is sequestration of parasitized red blood cells in the cerebral microvasculature. Malawi-based research using 0.35 Tesla (T) magnetic resonance imaging (MRI) established that severe brain swelling is associated with fatal CM, but swelling etiology remains unclear. Autopsy and clinical studies suggest several potential etiologies, but limitations of 0.35 T MRI precluded optimal investigations into swelling pathophysiology. A 1.5 T MRI in Zambia allowed for further investigations including susceptibility-weighted imaging (SWI). SWI is an ideal sequence for identifying regions of sequestration and microhemorrhages given the ferromagnetic properties of hemozoin and blood. Using 1.5 T MRI, Zambian children with retinopathy-confirmed CM underwent imaging with SWI, T2, T1 pre- and post-gadolinium, diffusion-weighted imaging (DWI) with apparent diffusion coefficients and T2/fluid attenuated inversion recovery sequences. Sixteen children including two with moderate/severe edema were imaged; all survived. Gadolinium extravasation was not seen. DWI abnormalities spared the gray matter suggesting vasogenic edema with viable tissue rather than cytotoxic edema. SWI findings consistent with microhemorrhages and parasite sequestration co-occurred in white matter regions where DWI changes consistent with vascular congestion were seen. Imaging findings consistent with posterior reversible encephalopathy syndrome were seen in children who subsequently had a rapid clinical recovery. High field MRI indicates that vascular congestion associated with parasite sequestration, local inflammation from microhemorrhages and autoregulatory dysfunction likely contribute to brain swelling in CM. No gross radiological blood brain barrier breakdown or focal cortical DWI abnormalities were evident in these children with nonfatal CM.

Malaria Pathogenesis

In the mosquito-human life cycle, the six species of malaria parasites infecting humans (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale wallickeri, Plasmodium ovale curtisi, Plasmodium malariae, and Plasmodium knowlesi) undergo 10 or more morphological states, replicate from single to 10,000+ cells, and vary in total population from one to many more than 10⁶ organisms. In the human host, only a small number of these morphological stages lead to clinical disease and the vast majority of all malaria-infected patients in the world produce few (if any) symptoms in the human. Human clinical disease (e.g., fever, anemia, coma) is the result of the parasite preprogrammed biology in concert with the human pathophysiological response. Caveats and corollaries that add variation to this host-parasite interaction include parasite genetic diversity of key proteins, coinfections, comorbidities, delays in treatment, human polymorphisms, and environmental determinants.

Laboratories as the Core for Health Systems Building

If it is accepted that health care access to diagnosis and treatment is a universal human right, the principal challenge is how to deliver that health care to all people. Health systems that function are the most effective way to deliver such care; these health systems should cover all of the diseases facing a population. The central role of laboratories in making medical decisions is crucial. If organizations engaged in health systems building tackle a disease category, such a cancer, multiple modalities within and outside of the laboratory have to be improved or installed to make an effective system.

Evaluation of Opportunities to Improve Hematopathology Diagnosis for Vietnam Pathologists

OBJECTIVES

We evaluate the need for, feasibility of, and impediments to improving hematopathology diagnoses for cancer hospitals in Vietnam.

METHODS

Two hematopathologists from the United States visited three major cancer treatment hospitals in Vietnam to workshop a sampling of difficult hematopathology cases. With Vietnamese pathologists, they toured histopathology, immunohistochemistry, and ancillary laboratory facilities.

RESULTS

Automated tissue processors and slide staining equipment were documented for each of the three hospitals. Between seven and 11 hematopathology cases were reviewed for each hospital. Exact/complete diagnostic concordance was 50% or less for all three laboratories. The major impediments to accurate specific diagnoses were limitations of immunohistochemical stains, limited stains available in house, and, for one of the hospitals, difficulty with interpretation of the immunohistochemistry.

CONCLUSIONS

Vietnamese pathologists would benefit from hematopathology training or opportunities to consult with hematopathologists in the United States. Expert hematopathology consultation services are currently unavailable within Vietnam, as postgraduate training for laboratory physicians consists of residency training in anatomic pathology only. Limitations in the quality of histopathology and immunohistochemistry could impose a barrier to success of efforts to improve hematopathology diagnosis. Implementation of a histopathology and immunohistochemistry quality improvement program might overcome this limitation.

Rapid Diagnostic Testing of Hospitalized Malawian Children Reveals Opportunities for Improved HIV Diagnosis and Treatment

Recent World Health Organization (WHO) guidelines recommend antiretroviral therapy (ART) for all HIV-infected people; previously CD4+ T lymphocyte quantification (CD4 count) or clinical staging determined eligibility for children ≥ 5 years old in low- and middle-income countries. We examined positive predictive value (PPV) of a rapid diagnostic test (RDT) algorithm and ART eligibility for hospitalized children with newly diagnosed HIV infection. We enrolled 363 hospitalized Malawian children age 2 months to 16 years with two serial positive HIV RDT from 2013 to 2015. Children aged ≤ 18 months whose nucleic acid testing was negative or unavailable were later excluded from the analysis (N = 16). If RNA PCR was undetectable, human immunodeficiency virus (HIV) enzyme immunoassay (EIA) and western blot (WB) were performed. Those with negative or discordant EIA and WB were considered HIV negative and excluded from further analysis (N = 6). ART eligibility was assessed using age, CD4 count, and clinical HIV stage. Among 150 patients with HIV RNA PCR results, 15 had undetectable HIV RNA. Of those, EIA and WB were positive in nine patients and negative or discordant in six patients. PPV of serial RDT was 90% versus RNA PCR alone and 96% versus combined RNA PCR, EIA, and WB. Of all patients aged ≥ 5 years, 8.9% were ineligible for ART under previous WHO guidelines. Improved HIV testing algorithms are needed for accurate diagnosis of HIV infection in children as prevalence of pediatric HIV declines. Universal treatment will significantly increase the numbers of older children who qualify for ART.

Transcriptional Categorization of the Etiology of Pneumonia Syndrome in Pediatric Patients in Malaria-Endemic Areas

Background

Pediatric acute respiratory distress in tropical settings is very common. Bacterial pneumonia is a major contributor to morbidity and mortality rates and requires adequate diagnosis for correct treatment. A rapid test that could identify bacterial (vs other) infections would have great clinical utility.

Methods and Results

We performed RNA (RNA-seq) sequencing and analyzed the transcriptomes of 68 pediatric patients with well-characterized clinical phenotype to identify transcriptional features associated with each disease class. We refined the features to predictive models (support vector machine, elastic net) and validated those models in an independent test set of 37 patients (80%-85% accuracy).

Conclusions

We have identified sets of genes that are differentially expressed in pediatric patients with pneumonia syndrome attributable to different infections and requiring different therapeutic interventions. Findings of this study demonstrate that human transcription signatures in infected patients recapitulate the underlying biology and provide models for predicting a bacterial diagnosis to inform treatment.

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.

A quantitative brain map of experimental cerebral malaria pathology

The murine model of experimental cerebral malaria (ECM) has been utilised extensively in recent years to study the pathogenesis of human cerebral malaria (HCM). However, it has been proposed that the aetiologies of ECM and HCM are distinct, and, consequently, no useful mechanistic insights into the pathogenesis of HCM can be obtained from studying the ECM model. Therefore, in order to determine the similarities and differences in the pathology of ECM and HCM, we have performed the first spatial and quantitative histopathological assessment of the ECM syndrome. We demonstrate that the accumulation of parasitised red blood cells (pRBCs) in brain capillaries is a specific feature of ECM that is not observed during mild murine malaria infections. Critically, we show that individual pRBCs appear to occlude murine brain capillaries during ECM. As pRBC-mediated congestion of brain microvessels is a hallmark of HCM, this suggests that the impact of parasite accumulation on cerebral blood flow may ultimately be similar in mice and humans during ECM and HCM, respectively. Additionally, we demonstrate that cerebrovascular CD8+ T-cells appear to co-localise with accumulated pRBCs, an event that corresponds with development of widespread vascular leakage. As in HCM, we show that vascular leakage is not dependent on extensive vascular destruction. Instead, we show that vascular leakage is associated with alterations in transcellular and paracellular transport mechanisms. Finally, as in HCM, we observed axonal injury and demyelination in ECM adjacent to diverse vasculopathies. Collectively, our data therefore shows that, despite very different presentation, and apparently distinct mechanisms, of parasite accumulation, there appear to be a number of comparable features of cerebral pathology in mice and in humans during ECM and HCM, respectively. Thus, when used appropriately, the ECM model may be useful for studying specific pathological features of HCM.

Abstract P2-05-07: Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries

Breast cancer care in the developing world is limited by access to quality ER and HER2 IHC diagnostic assays needed to justify hormone and HER2 therapeutics. Shipping pathology specimens to a central testing site often out of country delays therapy and is costly. The Xpert Breast Cancer Stratifier assay makes quantitative measurements of ESR1, PGR, ERBB2, and MKi67 mRNAs from FFPE specimens in &lt;2 hours on an easy-to-use automated diagnostic platform, the GeneXpert (GX). 10,000 GX machines are currently in use in 182 countries offering the possibility of a point-of-care solution. We compared concordance in tumor samples between IHC and mRNA intending to challenge the limits of the GX mRNA assay.

83 breast tumor samples were chosen including those with low cellularity, small volume disease, unusual subtypes, ER- tumors with surrounding benign epithelium, and low level HER2+ tumors. mRNA, IHC and FISH assays were performed. Slides were tested following macrodissection of invasive carcinoma and as non-macrodissected whole sections. GX measurements for Ki67 were compared with mitotic rate as an alternative to Ki67 IHC.

Overall percent agreement following macrodissection was 95% for ER, 89% for HER2, 76% for PR, and 80% for Ki67 (&gt;20% positive cut), and using whole section, 99% for ER, 80% for PR, 92% for HER2, and 73% for Ki67. Concordance was 92% for both macrodissection and whole section using mitotic rate to assess proliferation. Ignoring HER2 2+ calls which represented low level amplified tumors by FISH, the concordance rates were 95% for macrodissection and 99% for whole section. Discordance when testing long-term stored 4μm sections was resolved in a number of cases by using a fresh cut from the FFPE block. Half the ER discrepancies were in very small volume tumors ≤25mm2 and 75% were classified as ER-ve by IHC, and positive by Stratifier. 80% of ER IHC- cases were appropriately identified as ER- by the Stratifier in the presence of benign breast epithelium. HER2+ DCIS adjacent to HER2- invasive tumor resulted in a discrepant HER2 mRNA result even with macrodissection. No ER or HER2 discrepancies occurred in low cellularity tumors (≤30% cellularity) nor in lobular and mucinous subtypes.

In a study intended to challenge an mRNA breast biomarker assay, concordance between mRNA results and IHC was high for ER and HER2, the two most important prognostic markers needed for therapeutic decision making. Use of whole sections rather than tumor macrodissection did not decrease concordance. Discrepant ER cases were more prevalent when analyzing low volumes of tumor and in this setting were seen in ER IHC- tumors surrounded by ER+ normal epithelium, or with weak IHC expression, highlighting predictable limitations of the assay. Concordance was better between Ki67 mRNA and mitotic rate than with IHC. Re-test data suggested that a fresh cut of the FFPE block yields the best results by GX, perhaps due to mRNA degradation in stored 4μm sections. The Xpert Breast Cancer Stratifier may provide a rapid, cost-effective solution to the problem of obtaining accurate diagnostic results at the point-of-care in low resource settings, and deserves further evaluation in developing countries.

Citation Format: Brock JE, Milner DA, Ho K, Natalie W, Victor C, Annaliza R, Teresa B, Kathryn G-F, Edwin LW, Jodi W, Wendy W, Michael B. Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-07.

Statistical Literacy Among Academic Pathologists: A Survey Study to Gauge Knowledge of Frequently Used Statistical Tests Among Trainees and Faculty

Context.—Statistical literacy can be defined as understanding the statistical tests and terminology needed for the design, analysis, and conclusions of original research or laboratory testing. Little is known about the statistical literacy of clinical or anatomic pathologists.

Objective.—To determine the statistical methods most commonly used in pathology studies from the literature and to assess familiarity and knowledge level of these statistical tests by pathology residents and practicing pathologists.

Design.—The most frequently used statistical methods were determined by a review of 1100 research articles published in 11 pathology journals during 2015. Familiarity with statistical methods was determined by a survey of pathology trainees and practicing pathologists at 9 academic institutions in which pathologists were asked to rate their knowledge of the methods identified by the focused review of the literature.

Results.—We identified 18 statistical tests that appear frequently in published pathology studies. On average, pathologists reported a knowledge level between “no knowledge” and “basic knowledge” of most statistical tests. Knowledge of tests was higher for more frequently used tests. Greater statistical knowledge was associated with a focus on clinical pathology versus anatomic pathology, having had a statistics course, having an advanced degree other than an MD degree, and publishing research. Statistical knowledge was not associated with length of pathology practice.

Conclusions.—An audit of pathology literature reveals that knowledge of about 12 statistical tests would be sufficient to provide statistical literacy for pathologists. On average, most pathologists report they can interpret commonly used tests but are unable to perform them. Most pathologists indicated that they would benefit from additional statistical training.

Fusobacterium nucleatum in colorectal carcinoma tissue and patient prognosis

OBJECTIVE

Accumulating evidence links the intestinal microbiota and colorectal carcinogenesis. Fusobacterium nucleatum may promote colorectal tumour growth and inhibit T cell-mediated immune responses against colorectal tumours. Thus, we hypothesised that the amount of F. nucleatum in colorectal carcinoma might be associated with worse clinical outcome.

DESIGN

We used molecular pathological epidemiology database of 1069 rectal and colon cancer cases in the Nurses' Health Study and the Health Professionals Follow-up Study, and measured F. nucleatum DNA in carcinoma tissue. Cox proportional hazards model was used to compute hazard ratio (HR), controlling for potential confounders, including microsatellite instability (MSI, mismatch repair deficiency), CpG island methylator phenotype (CIMP), KRAS, BRAF, and PIK3CA mutations, and LINE-1 hypomethylation (low-level methylation).

RESULTS

Compared with F. nucleatum-negative cases, multivariable HRs (95% CI) for colorectal cancer-specific mortality in F. nucleatum-low cases and F. nucleatum-high cases were 1.25 (0.82 to 1.92) and 1.58 (1.04 to 2.39), respectively, (p for trend=0.020). The amount of F. nucleatum was associated with MSI-high (multivariable odd ratio (OR), 5.22; 95% CI 2.86 to 9.55) independent of CIMP and BRAF mutation status, whereas CIMP and BRAF mutation were associated with F. nucleatum only in univariate analyses (p<0.001) but not in multivariate analysis that adjusted for MSI status.

CONCLUSIONS

The amount of F. nucleatum DNA in colorectal cancer tissue is associated with shorter survival, and may potentially serve as a prognostic biomarker. Our data may have implications in developing cancer prevention and treatment strategies through targeting GI microflora by diet, probiotics and antibiotics.

Fusobacterium nucleatum in Colorectal Carcinoma Tissue According to Tumor Location

Objectives:

Evidence suggests a possible role of Fusobacterium nucleatum in colorectal carcinogenesis, especially in right-sided proximal colorectum. Considering a change in bowel contents and microbiome from proximal to distal colorectal segments, we hypothesized that the proportion of colorectal carcinoma enriched with F. nucleatum might gradually increase along the bowel subsites from rectum to cecum.

Methods:

A retrospective, cross-sectional analysis was conducted on 1,102 colon and rectal carcinomas in molecular pathological epidemiology databases of the Nurses’ Health Study and the Health Professionals Follow-up Study. We measured the amount of F. nucleatum DNA in colorectal tumor tissue using a quantitative PCR assay and equally dichotomized F. nucleatum-positive cases (high vs. low). We used multivariable logistic regression analysis to examine the relationship of a bowel subsite variable (rectum, rectosigmoid junction, sigmoid colon, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon, and cecum) with the amount of F. nucleatum.

Results:

The proportion of F. nucleatum-high colorectal cancers gradually increased from rectal cancers (2.5% 4/157) to cecal cancers (11% 19/178), with a statistically significant linear trend along all subsites (P<0.0001) and little evidence of non-linearity. The proportion of F. nucleatum-low cancers was higher in rectal, ascending colon, and cecal cancers than in cancers of middle segments.

Conclusions:

The proportion of F. nucleatum-high colorectal cancers gradually increases from rectum to cecum. Our data support the colorectal continuum model that reflects pathogenic influences of the gut microbiota on neoplastic and immune cells and challenges the prevailing two-colon (proximal vs. distal) dichotomy paradigm.

Responses to Bacteria, Virus, and Malaria Distinguish the Etiology of Pediatric Clinical Pneumonia

RATIONALE

Plasma-detectable biomarkers that rapidly and accurately diagnose bacterial infections in children with suspected pneumonia could reduce the morbidity of respiratory disease and decrease the unnecessary use of antibiotic therapy.

OBJECTIVES

Using 56 markers measured in a multiplexed immunoassay, we sought to identify proteins and protein combinations that could discriminate bacterial from viral or malarial diagnoses.

METHODS

We selected 80 patients with clinically diagnosed pneumonia (as defined by the World Health Organization) who also met criteria for bacterial, viral, or malarial infection based on clinical, radiographic, and laboratory results. Ten healthy community control subjects were enrolled to assess marker reliability. Patients were subdivided into two sets: one for identifying potential markers and another for validating them.

MEASUREMENTS AND MAIN RESULTS

Three proteins (haptoglobin, tumor necrosis factor receptor 2 or IL-10, and tissue inhibitor of metalloproteinases 1) were identified that, when combined through a classification tree signature, accurately classified patients into bacterial, malarial, and viral etiologies and misclassified only one patient with bacterial pneumonia from the validation set. The overall sensitivity and specificity of this signature for the bacterial diagnosis were 96 and 86%, respectively. Alternative combinations of markers with comparable accuracy were selected by support vector machine and regression models and included haptoglobin, IL-10, and creatine kinase-MB.

CONCLUSIONS

Combinations of plasma proteins accurately identified children with a respiratory syndrome who were likely to have bacterial infections and who would benefit from antibiotic therapy. When used in conjunction with malaria diagnostic tests, they may improve diagnostic specificity and simplify treatment decisions for clinicians.

ASCP's Partners for Cancer Diagnosis and Treatment in Africa

Abstract 38

A primary goal of any health care system should be to attain universal access for all patients within a catchment area. The cancer care model requires that physicians encountering patients who they suspect of having a malignancy have access to a system that ensures rapid, accurate, and reliable pathology for primary diagnosis of cancer. Sub-Saharan Africa faces immense challenges in providing adequate coverage. Each region, country, and district has unique obstacles to overcome when meeting the health needs of the population. The American Society of Clinical Pathology (ASCP), in partnership with the White House Office of Science Technology Policy and the Clinton Global Initiative, recently launched a $26.5 million multi-year initiative. The initiative begins with assessment of potential countries with the greatest need--including collaboration and capacity program building with local officials and staff--to deploy full service pathology infrastructure for eligible countries to strategically meet their population needs. Working in parallel and together, steering committees for Diagnostics and Technology, Care and Treatment, In-Country Medical Education, Bioethics, and Monitoring & Evaluation have focused on each potential country to optimize success. The maximal intervention includes deployment of automated histopathology systems and integrated whole slide imaging systems. Imaging systems are linked through a customized laboratory information system to a dedicated team of pathologists from the United States. This long-term project will roll out to 10 or more countries in Africa as well as Haiti. An overview of the project will be presented as well as experiences data from countries launched to date.

AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST:

No COIs from either author.

Neuropathology of Zika Virus Infection

Zika virus (ZIKV) is a member of the Flaviviridae family that had been associated only with mild disease prior to the 2015 outbreak in Brazil. A dramatic increase in reported cases of microcephaly and Guillain-Barré syndrome during this time prompted significant research into possible associations with ZIKV and its neurotropic properties. Infection of neural progenitor cells and organoids have been shown to induce apoptosis and dysregulation of growth, and mouse studies have demonstrated viral replication in brain tissue in adults, as well as vertical transmission resulting in embryonic brain abnormalities. Large case series of clinical and radiological findings of congenital ZIKV infection have begun to be published; however, pathology reports have been limited to two case reports and two small case series. Thus far, the findings have largely been restricted to the brain and include diffuse grey and white matter involvement consisting of dystrophic calcifications, gliosis, microglial nodules, neuronophagia, and scattered lymphocytes. Mild chronic villitis was observed in the placental tissue in some cases, and the remaining organs were essentially uninvolved. Larger, systematic studies, including correlation of histological findings with gestational age at the time of maternal infection, will be required to determine the full range of Zika virus-induced abnormalities and to help guide future clinical decision making.

Clinical Sequencing Uncovers Origins and Evolution of Lassa Virus

The 2013-2015 West African epidemic of Ebola virus disease (EVD) reminds us of how little is known about biosafety level 4 viruses. Like Ebola virus, Lassa virus (LASV) can cause hemorrhagic fever with high case fatality rates. We generated a genomic catalog of almost 200 LASV sequences from clinical and rodent reservoir samples. We show that whereas the 2013-2015 EVD epidemic is fueled by human-to-human transmissions, LASV infections mainly result from reservoir-to-human infections. We elucidated the spread of LASV across West Africa and show that this migration was accompanied by changes in LASV genome abundance, fatality rates, codon adaptation, and translational efficiency. By investigating intrahost evolution, we found that mutations accumulate in epitopes of viral surface proteins, suggesting selection for immune escape. This catalog will serve as a foundation for the development of vaccines and diagnostics. VIDEO ABSTRACT.

Evidence for spleen dysfunction in malaria-HIV co-infection in a subset of pediatric patients

The spleen has an important role in the clearance of malaria parasites, and the role of HIV co-infection on this process is yet to be described. Using a combination of histological and molecular methods, we systematically evaluated parasite load across multiple organs from HIV-positive and HIV-negative cases of an autopsy study of pediatric comatose children with malaria infection (n=103) in Blantyre, Malawi. Quantification of parasite load across organs was done using histology. A subset of cases was further characterized for parasite localization and stage of development using immunohistochemistry-based labeling of parasite and host cells (5 HIV-positive, 10 HIV-negative), and quantitative RT-PCR (qRT-PCR) of asexual and sexual-specific genes (4 HIV-positive, 5 HIV-negative). The results were compared with clinical information including HIV status. The HIV-positive rate was 21% for the group studied (20 of 95) and HIV-positive patients had a significantly shorter duration of time between onset of illness and death, and were significantly older than HIV-negative patients. We found that spleens of HIV-positive cases had significantly higher parasite loads compared with those of HIV-negative cases in each of the three methods we used: (i) standard histology, (ii) immunohistochemistry-based labeling of Plasmodium lactate dehydrogenase (pLDH), and (iii) molecular detection of asexual parasite transcript apical membrane antigen 1 (AMA1). Immunohistochemistry-based labeling of macrophage marker CD163 in a subset of spleens revealed fewer activated macrophages containing engulfed parasites and a greater number of free unphagocytosed parasites in the HIV-positive cases. The mechanism by which HIV infection is associated with more rapid progression to severe cerebral malaria disease is possibly impairment of parasite destruction by splenic macrophages, supported by published in vitro studies showing inefficient phagocytosis of malaria parasites by HIV-infected macrophages.

Fusobacterium nucleatum and T Cells in Colorectal Carcinoma

IMPORTANCE

Evidence indicates a complex link between gut microbiome, immunity, and intestinal tumorigenesis. To target the microbiota and immunity for colorectal cancer prevention and therapy, a better understanding of the relationship between microorganisms and immune cells in the tumor microenvironment is needed. Experimental evidence suggests that Fusobacterium nucleatum may promote colonic neoplasia development by downregulating antitumor T cell-mediated adaptive immunity.

OBJECTIVE

To test the hypothesis that a greater amount of F nucleatum in colorectal carcinoma tissue is associated with a lower density of T cells in tumor tissue.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional analysis was conducted on 598 rectal and colon carcinoma cases in 2 US nationwide prospective cohort studies with follow-up through 2006, the Nurses' Health Study (participants enrolled in 1976) and the Health Professionals Follow-up Study (participants enrolled in 1986). Tissue collection and processing were performed from 2002 through 2008, and immunity assessment, 2008 through 2009. From 2013 through 2014, the amount of F nucleatum in colorectal carcinoma tissue was measured by quantitative polymerase chain reaction assay; we equally dichotomized positive cases (high vs low). Multivariable ordinal logistic regression analysis was conducted in 2014 to assess associations of the amount of F nucleatum with densities (quartiles) of T cells in tumor tissue, controlling for clinical and tumor molecular features, including microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element-1 (LINE-1) methylation, and KRAS, BRAF, and PIK3CA mutation status. We adjusted the 2-sided α level to .013 for multiple hypothesis testing.

MAIN OUTCOMES AND MEASURES

Densities of CD3+, CD8+, CD45RO (protein tyrosine phosphatase receptor type C [PTPRC])+, and FOXP3+ T cells in tumor tissue, determined by means of tissue microarray immunohistochemical analysis and computer-assisted image analysis.

RESULTS

F nucleatum was detected in colorectal carcinoma tissue in 76 (13%) of 598 cases. Compared with F nucleatum-negative cases, F nucleatum-high cases were inversely associated with the density of CD3+ T cells (for a unit increase in quartile categories of CD3+ T cells as an outcome: multivariable odds ratio, 0.47 [95% CI, 0.26-0.87]; P for trend = .006). The amount of F nucleatum was not significantly associated with the density of CD8+, CD45RO+, or FOXP3+ T cells (P fortrend = .24, .88, and .014, respectively).

CONCLUSIONS AND RELEVANCE

The amount of tissue F nucleatum is inversely associated with CD3+ T-cell density in colorectal carcinoma tissue. On validation, our human population data may provide an impetus for further investigations on potential interactive roles of Fusobacterium and host immunity in colon carcinogenesis.

Fusobacterium nucleatum and T Cells in Colorectal Carcinoma

IMPORTANCE

Evidence indicates a complex link between gut microbiome, immunity, and intestinal tumorigenesis. To target the microbiota and immunity for colorectal cancer prevention and therapy, a better understanding of the relationship between microorganisms and immune cells in the tumor microenvironment is needed. Experimental evidence suggests that Fusobacterium nucleatum may promote colonic neoplasia development by downregulating antitumor T cell-mediated adaptive immunity.

OBJECTIVE

To test the hypothesis that a greater amount of F nucleatum in colorectal carcinoma tissue is associated with a lower density of T cells in tumor tissue.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional analysis was conducted on 598 rectal and colon carcinoma cases in 2 US nationwide prospective cohort studies with follow-up through 2006, the Nurses' Health Study (participants enrolled in 1976) and the Health Professionals Follow-up Study (participants enrolled in 1986). Tissue collection and processing were performed from 2002 through 2008, and immunity assessment, 2008 through 2009. From 2013 through 2014, the amount of F nucleatum in colorectal carcinoma tissue was measured by quantitative polymerase chain reaction assay; we equally dichotomized positive cases (high vs low). Multivariable ordinal logistic regression analysis was conducted in 2014 to assess associations of the amount of F nucleatum with densities (quartiles) of T cells in tumor tissue, controlling for clinical and tumor molecular features, including microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element-1 (LINE-1) methylation, and KRAS, BRAF, and PIK3CA mutation status. We adjusted the 2-sided α level to .013 for multiple hypothesis testing.

MAIN OUTCOMES AND MEASURES

Densities of CD3+, CD8+, CD45RO (protein tyrosine phosphatase receptor type C [PTPRC])+, and FOXP3+ T cells in tumor tissue, determined by means of tissue microarray immunohistochemical analysis and computer-assisted image analysis.

RESULTS

F nucleatum was detected in colorectal carcinoma tissue in 76 (13%) of 598 cases. Compared with F nucleatum-negative cases, F nucleatum-high cases were inversely associated with the density of CD3+ T cells (for a unit increase in quartile categories of CD3+ T cells as an outcome: multivariable odds ratio, 0.47 [95% CI, 0.26-0.87]; P for trend = .006). The amount of F nucleatum was not significantly associated with the density of CD8+, CD45RO+, or FOXP3+ T cells (P fortrend = .24, .88, and .014, respectively).

CONCLUSIONS AND RELEVANCE

The amount of tissue F nucleatum is inversely associated with CD3+ T-cell density in colorectal carcinoma tissue. On validation, our human population data may provide an impetus for further investigations on potential interactive roles of Fusobacterium and host immunity in colon carcinogenesis.

Implementation and Validation of Telepathology Triage at Cancer Referral Center in Rural Rwanda

Purpose

Connecting a cancer patient to the appropriate treatment requires the correct diagnosis provided in a timely manner. In resource-limited settings, the anatomic pathology bridge to efficient, accurate, and timely cancer care is often challenging. In this study, we present the first phase of an anatomic telepathology triage system, which was implemented and validated at the Butaro District Hospital in northern rural Rwanda.

Methods

Select cases over a 9-month period in three segments were evaluated by static image telepathology and were independently evaluated by standard glass slide histology. Each case via telepathology was classified as malignant, benign, infectious/inflammatory, or nondiagnostic and was given an exact histologic diagnosis.

Results

For cases triaged as appropriate for telepathology, correlation with classification and exact diagnosis demonstrated greater than 95% agreement over the study. Cases in which there was disagreement were analyzed for cause, and the triage process was adjusted to avoid future problems.

Conclusion

Challenges to obtaining a correct and complete diagnosis with telepathology alone included the need for immunohistochemistry, assessment of the quality of images, and the lack of images representing an entire sample. The next phase of the system will assess the effect of telepathology triage on turnaround time and the value of on-site immunohistochemistry in reducing that metric and the need for evaluation outside of telepathology.

Integration of molecular pathology, epidemiology and social science for global precision medicine

The precision medicine concept and the unique disease principle imply that each patient has unique pathogenic processes resulting from heterogeneous cellular genetic and epigenetic alterations and interactions between cells (including immune cells) and exposures, including dietary, environmental, microbial and lifestyle factors. As a core method field in population health science and medicine, epidemiology is a growing scientific discipline that can analyze disease risk factors and develop statistical methodologies to maximize utilization of big data on populations and disease pathology. The evolving transdisciplinary field of molecular pathological epidemiology (MPE) can advance biomedical and health research by linking exposures to molecular pathologic signatures, enhancing causal inference and identifying potential biomarkers for clinical impact. The MPE approach can be applied to any diseases, although it has been most commonly used in neoplastic diseases (including breast, lung and colorectal cancers) because of availability of various molecular diagnostic tests. However, use of state-of-the-art genomic, epigenomic and other omic technologies and expensive drugs in modern healthcare systems increases racial, ethnic and socioeconomic disparities. To address this, we propose to integrate molecular pathology, epidemiology and social science. Social epidemiology integrates the latter two fields. The integrative social MPE model can embrace sociology, economics and precision medicine, address global health disparities and inequalities, and elucidate biological effects of social environments, behaviors and networks. We foresee advancements of molecular medicine, including molecular diagnostics, biomedical imaging and targeted therapeutics, which should benefit individuals in a global population, by means of an interdisciplinary approach of integrative MPE and social health science.

Oncologic Care and Pathology Resources in Africa: Survey and Recommendations

The connection of a clinician who identifies a patient with signs and symptoms of malignancy to an oncologist who has the tools to treat a patient's cancer requires a diagnostic pathology laboratory to receive, process, and diagnose the tumor. Without an accurate classification, nothing is known of diagnosis, prognosis, or treatment by the clinical team, and most important, the patient is left scared, confused, and without hope. The vast majority of deaths from malignancies occur in sub-Saharan Africa primarily as a result of lack of public awareness of cancer and how it is diagnosed and treated in the setting of a severe lack of resources (physical and personnel) to actually diagnose tumors. To correct this massive health disparity, a plan of action is required across the continent of Africa to bring diagnostic medicine into the modern era and connect patients with the care they desperately need. We performed a survey of resources in Africa for tissue diagnosis of cancer and asked quantitative questions about tools, personnel, and utilization. We identified a strong correlation between pathology staffing and capacity to provide pathology services. On the basis of this survey and through a congress of concerned pathologists, we propose strategies that will catapult the continent into an era of high-quality pathology services with resultant improvement in cancer outcomes.

Epidemiologic Investigation of a Cluster of Neuroinvasive Bacillus cereus Infections in 5 Patients With Acute Myelogenous Leukemia

Background.  Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods.  Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results.  All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9-20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions.  The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts.

If It's Not One Thing, It's Another: An Inverse Relationship of Malignancy and Atherosclerotic Disease

Atherosclerosis and malignancy are pervasive pathological conditions that account for the bulk of morbidity and mortality in developed countries. Our current understanding of the patholobiology of these fundamental disorders suggests that inflammatory processes may differentially affect them; thus, atherosclerosis can be largely driven by inflammation, where as cancer often flourishes as inflammatory responses are modulated. A corollary of this hypothesis is that cancer (or its treatment may significantly attenuate atherosclerotic disease by diminishing host inflammatory response, suggesting potential therapeutic approaches. To evaluate the relationship between cancer and cardiovascular atherosclerotic disease, we assessed 1,024 autopsy reports from Brigham and Women's Hospital and performed correlative analyses on atherosclerotic severity and cancer prevalence. In gender- and age-matched populations, there is a statistically significant inverse correlation between history of malignancy and autopsy-proven atherosclerotic disease. In a second analysis, we evaluated 147,779 patients through analysis of the Harvard Catalyst SHRINE database and demonstrated a reduced non-coronary atherosclerotic disease rate: control (27.40%), leukemia/lymphoma (12.57%), lung (17.63%), colorectal (18.17%), breast (9.79%), uterus/cervix (11.47%), and prostate (18.40%). We herein report that, based on two separate medical records analysis, an inverse correlation between cancer and atherosclerosis. Furthermore, this correlation is not uniformly associated with anti-neoplastic treatment, suggesting that the inverse relationship may be in part attributable to an individual's intrinsic inflammatory propensity, and/or to inflammation-modulatory properties of neoplasms.

Quantitative Assessment of Multiorgan Sequestration of Parasites in Fatal Pediatric Cerebral Malaria

Children in sub-Saharan Africa continue to acquire and die from cerebral malaria, despite efforts to control or eliminate the causative agent, Plasmodium falciparum. We present a quantitative histopathological assessment of the sequestration of parasitized erythrocytes in multiple organs obtained during a prospective series of 103 autopsies performed between 1996 and 2010 in Blantyre, Malawi, on pediatric patients who died from cerebral malaria and controls. After the brain, sequestration of parasites was most intense in the gastrointestinal tract, both in patients with cerebral malaria and those with parasitemia in other organs. Within cases of histologically defined cerebral malaria, which includes phenotypes termed "sequestration only" (CM1) and "sequestration with extravascular pathology" (CM2), CM1 was associated with large parasite numbers in the spleen and CM2 with intense parasite sequestration in the skin. A striking histological finding overall was the marked sequestration of parasitized erythrocytes across most organs in patients with fatal cerebral malaria, supporting the hypothesis that the disease is, in part, a result of a high level of total-body parasite sequestration.

Brain swelling and death in children with cerebral malaria

BACKGROUND

Case fatality rates among African children with cerebral malaria remain in the range of 15 to 25%. The key pathogenetic processes and causes of death are unknown, but a combination of clinical observations and pathological findings suggests that increased brain volume leading to raised intracranial pressure may play a role. Magnetic resonance imaging (MRI) became available in Malawi in 2009, and we used it to investigate the role of brain swelling in the pathogenesis of fatal cerebral malaria in African children.

METHODS

We enrolled children who met a stringent definition of cerebral malaria (one that included the presence of retinopathy), characterized them in detail clinically, and obtained MRI scans on admission and daily thereafter while coma persisted.

RESULTS

Of 348 children admitted with cerebral malaria (as defined by the World Health Organization), 168 met the inclusion criteria, underwent all investigations, and were included in the analysis. A total of 25 children (15%) died, 21 of whom (84%) had evidence of severe brain swelling on MRI at admission. In contrast, evidence of severe brain swelling was seen on MRI in 39 of 143 survivors (27%). Serial MRI scans showed evidence of decreasing brain volume in the survivors who had had brain swelling initially.

CONCLUSIONS

Increased brain volume was seen in children who died from cerebral malaria but was uncommon in those who did not die from the disease, a finding that suggests that raised intracranial pressure may contribute to a fatal outcome. The natural history indicates that increased intracranial pressure is transient in survivors. (Funded by the National Institutes of Health and Wellcome Trust U.K.).