Compartmentalization of simian immunodeficiency virus replication within secondary lymphoid tissues of rhesus macaques is linked to disease stage and inversely related to localization of virus-specific CTL.

We previously demonstrated that HIV replication is concentrated in lymph node B cell follicles during chronic infection and that HIV-specific CTL fail to accumulate in large numbers at those sites. It is unknown whether these observations can be generalized to other secondary lymphoid tissues or whether virus compartmentalization occurs in the absence of CTL. We evaluated these questions in SIVmac239-infected rhesus macaques by quantifying SIV RNA(+) cells and SIV-specific CTL in situ in spleen, lymph nodes, and intestinal tissues obtained at several stages of infection. During chronic asymptomatic infection prior to simian AIDS, SIV-producing cells were more concentrated in follicular (F) compared with extrafollicular (EF) regions of secondary lymphoid tissues. At day 14 of infection, when CTL have minimal impact on virus replication, there was no compartmentalization of SIV-producing cells. Virus compartmentalization was diminished in animals with simian AIDS, which often have low-frequency CTL responses. SIV-specific CTL were consistently more concentrated within EF regions of lymph node and spleen in chronically infected animals regardless of epitope specificity. Frequencies of SIV-specific CTL within F and EF compartments predicted SIV RNA(+) cells within these compartments in a mixed model. Few SIV-specific CTL expressed the F homing molecule CXCR5 in the absence of the EF retention molecule CCR7, possibly accounting for the paucity of F CTL. These findings bolster the hypothesis that B cell follicles are immune privileged sites and suggest that strategies to augment CTL in B cell follicles could lead to improved viral control and possibly a functional cure for HIV infection.

Early death from childhood cancer: First medical record-level analysis reveals insights on diagnostic timing and cause of death.

BACKGROUND: Approximately 7.5% of pediatric cancer deaths occur in the first 30 days post diagnosis, termed early death (ED). Previous database-level analyses identified increased ED in Black/Hispanic patients, infants, late adolescents, those in poverty, and with specific diagnoses. Socioeconomic and clinical risk factors have never been assessed at the medical record level and are poorly understood. METHODS: We completed a retrospective case-control study of oncology patients diagnosed from 1995 to 2016 at Children's Hospital Colorado. The ED group (n = 45) was compared to a non-early death (NED) group surviving >31 days, randomly selected from the same cohort (n = 44). Medical records and death certificates were manually reviewed for sociodemographic and clinical information to identify risk factors for ED. RESULTS: We identified increased ED risk in central nervous system (CNS) tumors and, specifically, high-grade glioma and atypical teratoid/rhabdoid tumor. There was prolonged time from symptom onset to seeking care in the ED group (29.4 vs. 9.8 days) with similar time courses to diagnosis thereafter. Cause of death was most commonly from tumor progression in brain/CNS tumors and infection in hematologic malignancies. CONCLUSIONS: In this first medical record-level analysis of ED, we identified socioeconomic and clinical risk factors. ED was associated with longer time from first symptoms to presentation, suggesting that delayed presentation may be an addressable risk factor. Many individual patient-level risk factors, including socioeconomic measures and barriers to care, were unable to be assessed through record review, highlighting the need for a prospective study to understand and address childhood cancer ED.

A rare case of an isolated PAX6 mutation, aniridia, and Wilms tumor.

Introduction: Wilms tumor (WT) is the most common renal malignancy of children and can be seen in WAGR syndrome (WT, aniridia, genitourinary anomalies, and intellectual disability). WAGR results from a contiguous gene deletion within the 11p13 region, encompassing the WT1 gene, often responsible for WT development, and the PAX6 gene, responsible for aniridia. Aniridia, a pan-ocular disease resulting from iris hypoplasia, is thought to increase the risk for WT development if their genetic alteration spans both the WT1 and the PAX6 genes on 11p13.Case Description: We describe a unique case of a patient with aniridia secondary to a heterozygous PAX6 nonsense mutation who developed WT despite no additional identifiable germline genetic drivers for this disease.Discussion: Isolated mutations in PAX6 previously have not been associated with increased risk of WT development case raises the question of if surveillance for WT should be continued in patients with aniridia with an isolated PAX6 mutation identified.

Novel RAF Fusions in Pediatric Low-Grade Gliomas Demonstrate MAPK Pathway Activation.

Brain tumors are the most common solid tumor in children, and low-grade gliomas (LGGs) are the most common childhood brain tumor. Here, we report on 3 patients with LGG harboring previously unreported or rarely reported RAF fusions: FYCO1-RAF1, CTTNBP2-BRAF, and SLC44A1-BRAF. We hypothesized that these tumors would show molecular similarity to the canonical KIAA1549-BRAF fusion that is the most widely seen alteration in pilocytic astrocytoma (PA), the most common pediatric LGG variant, and that this similarity would include mitogen-activated protein kinase (MAPK) pathway activation. To test our hypothesis, we utilized immunofluorescent imaging and RNA-sequencing in normal brain, KIAA1549-BRAF-harboring tumors, and our 3 tumors with novel fusions. We performed immunofluorescent staining of ERK and phosphorylated ERK (p-ERK), identifying increased p-ERK expression in KIAA1549-BRAF fused PA and the novel fusion samples, indicative of MAPK pathway activation. Geneset enrichment analysis further confirmed upregulated downstream MAPK activation. These results suggest that MAPK activation is the oncogenic mechanism in noncanonical RAF fusion-driven LGG. Similarity in the oncogenic mechanism suggests that LGGs with noncanonical RAF fusions are likely to respond to MEK inhibitors.

Ending student mistreatment: early successes and continuing challenges.

Problem: Student mistreatment represents an ongoing challenge for US medical schools. Students experiencing mistreatment may become marginalized and cynical, and they have higher rates of burnout, depression and substance use disorders. Although numerous attempts to eliminate mistreatment have been proposed, best practices remain elusive. We formed a unique student-faculty collaboration (the Ending Mistreatment Task Force) that allowed all voices to be heard and enabled identification of five interventions to reduce mistreatment.Intervention: The EMTF developed and implemented five key interventions: 1) a shared mistreatment definition; 2) measures to increase faculty accountability, including adding professionalism expectations to faculty members' contracts and performance reviews; 3) a Professionalism Office to respond promptly to students' reports of mistreatment and provide feedback to faculty; 4) tools to help teachers provide authentic learning environments for students, while addressing generational misunderstandings; and 5) student-produced videos, helping faculty understand the impact of mistreatment as seen through students' eyes.Context: These interventions occurred at one medical school where mistreatment reports were consistently above national averages.Impact: Over 6 years, the interventions helped reduce the rate of student-reported mistreatment by 36% compared with a 4% decline across all US medical schools.Lessons: The collaborations between students and faculty helped each party identify unexpected misunderstandings and challenges. We learned that students want hard questions, although faculty are often afraid to challenge students for fear of offending them or being reported. We clarified differences between mistreatment and sub-optimal learning environments and openly discussed the pervasive opinion that 'some' mistreatment is important for learning. We also identified ongoing challenges, including the need to solicit residents' perspectives regarding mistreatment and develop proper responses to disrespectful comments directed at patients, family and colleagues. The collaboration reinforced students' and faculty members' shared commitment to upholding a respectful learning and clinical care environment and ending mistreatment.