CSF-1 maintains pathogenic but not homeostatic myeloid cells in the central nervous system during autoimmune neuroinflammation.

The receptor for colony stimulating factor 1 (CSF-1R) is important for the survival and function of myeloid cells that mediate pathology during experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). CSF-1 and IL-34, the ligands of CSF-1R, have similar bioactivities but distinct tissue and context-dependent expression patterns, suggesting that they have different roles. This could be the case in EAE, given that CSF-1 expression is up-regulated in the CNS, while IL-34 remains constitutively expressed. We found that targeting CSF-1 with neutralizing antibody halted ongoing EAE, with efficacy superior to CSF-1R inhibitor BLZ945, whereas IL-34 neutralization had no effect, suggesting that pathogenic myeloid cells were maintained by CSF-1. Both anti­CSF-1 and BLZ945 treatment greatly reduced the number of monocyte-derived cells and microglia in the CNS. However, anti­CSF-1 selectively depleted inflammatory microglia and monocytes in inflamed CNS areas, whereas BLZ945 depleted virtually all myeloid cells, including quiescent microglia, throughout the CNS. Anti­CSF-1 treatment reduced the size of demyelinated lesions and microglial activation in the gray matter. Lastly, we found that bone marrow­derived immune cells were the major mediators of CSF-1R­dependent pathology, while microglia played a lesser role. Our findings suggest that targeting CSF-1 could be effective in ameliorating MS pathology, while preserving the homeostatic functions of myeloid cells, thereby minimizing risks associated with ablation of CSF-1R­dependent cells.

Effect of p16 Status on Survival Outcomes in Sinonasal Squamous Cell Carcinoma.

OBJECTIVE: Evaluate the effect of p16 status on disease-free survival (DFS) and overall survival (OS) in patients with sinonasal squamous cell carcinoma (SCC) undergoing treatment with curative intent; and to assess how p16 status may affect patterns of recurrence. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary medical center. METHODS: Patients with sinonasal SCC treated with curative intent from 2012 to 2018 were identified. Independent variable of interest was p16 status, which was assessed using immunohistochemistry (IHC) with a 70% staining cutoff for positivity. Kaplan Meier survival curve was plotted to assess correlation between p16 status and DFS and OS. Association between recurrence patterns and p16 status was conducted using chi square and fisher's exact tests. Multivariable Cox proportional hazard analysis was conducted to assess association between independent variables and DFS. RESULTS: Fifty patients with sinonasal SCC met inclusion criteria. Patients were p16 positive in 28/50 (56%) of cases. Kaplan Meier survival curve revealed no statistically significant association between p16 status and DFS or OS survival (P = .780, P = .474). There was no difference in recurrence patterns in patients with p16 positive versus negative tumors. CONCLUSION: p16 status did not have prognostic value on DFS and OS in our cohort of patients with sinonasal SCC undergoing treatment with curative intent. There was no difference in recurrence patterns between the 2 populations. Based on the results of this study, p16 status should not impact counseling of patients as it relates to their prognosis from SNM.

Cladophialophora bantiana brain abscess and concurrent pulmonary cryptococcus neoformans infection in a patient twenty years after renal transplantation.

Recipients of solid organ transplants are at risk for a variety of infections due to their immunocompromised status. The types of infections are often correlated to the timing from their transplant. After about six to twelve months, transplant recipients remain at risk for typical community acquired pathogens, late viral infections, and fungal infections including atypical molds such as Cladophialophora bantiana. C. bantiana is a dematiaceous fungus that has a predilection for infecting the brain and is the most common cause of cerebral phaeohyphomycosis - a term used to describe infections caused by molds that produce dark cell walls. Patients with cerebral abscesses due to C. bantiana infections have an estimated mortality of about 70%. Improved outcomes have been seen in patients who receive both surgical and antifungal therapy. While there are no clear guidelines on antifungal therapy, most cases have been treated with combination amphotericin B, a triazole (itraconazole, voriconazole, or posaconazole) with flucytosine sometimes in conjunction as well. This case describes a patient with C. bantiana brain abscess and concurrent Cryptococcus neoformans pulmonary infection that occurred twenty years after his kidney transplantation. He was treated successfully with two craniotomies for cerebral abscess debridement and liposomal amphotericin B followed by planned lifelong voriconazole.

GATA1 controls numbers of hematopoietic progenitors and their response to autoimmune neuroinflammation.

GATA-binding factor 1 (GATA1) is a transcription factor that governs the development and function of multiple hematopoietic cell lineages. GATA1 is expressed in hematopoietic stem and progenitor cells (HSPCs) and is essential for erythroid lineage commitment; however, whether it plays a role in hematopoietic stem cell (HSC) biology and the development of myeloid cells, and what that role might be, remains unclear. We initially set out to test the role of eosinophils in experimental autoimmune encephalomyelitis (EAE), a model of central nervous system autoimmunity, using mice lacking a double GATA-site (ΔdblGATA), which lacks eosinophils due to the deletion of the dblGATA enhancer to Gata1, which alters its expression. ΔdblGATA mice were resistant to EAE, but not because of a lack of eosinophils, suggesting that these mice have an additional defect. ΔdblGATA mice with EAE had fewer inflammatory myeloid cells than the control mice, suggesting that resistance to EAE is caused by a defect in myeloid cells. Naïve ΔdblGATA mice also showed reduced frequency of CD11b+ myeloid cells in the blood, indicating a defect in myeloid cell production. Examination of HSPCs revealed fewer HSCs and myeloid cell progenitors in the ΔdblGATA bone marrow (BM), and competitive BM chimera experiments showed a reduced capacity of the ΔdblGATA BM to reconstitute immune cells, suggesting that reduced numbers of ΔdblGATA HSPCs cause a functional deficit during inflammation. Taken together, our data show that GATA1 regulates the number of HSPCs and that reduced GATA1 expression due to dblGATA deletion results in a diminished immune response following the inflammatory challenge.

Mucormycosis Leading to Cerebral Edema and Cerebellar Tonsillar Herniation after Allogeneic Bone Marrow Transplant: A Case Report.

INTRODUCTION: Mucormycosis following hematopoietic stem cell transplant (HSCT) carries a very high mortality rate. Pulmonary mucormycosis often leads to systemic dissemination and eventual death. It is imperative for transplant providers to have a high level of suspicion for mucormycosis and initiate early treatment. Here, we present a 64-year-old woman who died of disseminated mucormycosis 13 days following her allogeneic HSCT. CASE PRESENTATION: A 64-year-old female with a history of acute myeloid leukemia (AML) presented for allogeneic HSCT and passed away from intracerebral hemorrhage secondary to mucormycosis infection 13 days following her transplant. On autopsy, it was found she had angioinvasive mucormycosis in her frontal lobe leading to cerebral edema which eventually led to tonsillar herniation and brainstem infarction. Her lungs were the likely source of infectious dissemination. DISCUSSION: This case represents an unusual course of events following HSCT in that no other published case shows tonsillar herniation resulting from mucormycosis-related intracerebral swelling. We also report this case because it is believed mucormycosis in HSCT patients is underreported. Additionally, our case highlights the importance of increased vigilance for mucormycosis in patients with prolonged neutropenia prior to HSCT and the potential link of voriconazole prophylaxis and increased risk for mucormycosis.

Takayasu's arteritis is associated with HLA-B*52, but not with HLA-B*51, in Turkey.

INTRODUCTION: HLA-B*51 and HLA-B*52 are two close human leukocyte antigen (HLA) allele groups with minor amino acid differences. However, they are associated with two different vasculitides (HLA-B*51 in Behçet's disease and HLA-B*52 in Takayasu's arteritis (TAK)) and with major clinical and immunological differences. In this study, we aimed to screen a large cohort of TAK patients from Turkey for the presence of HLA-B*51 and HLA-B*52 as susceptibility and severity factors. METHODS: TAK patients (n = 330) followed at a total of 15 centers were included in the study. The mean age of the patients was 37.8 years, and 86% were women. DNA samples from the patients and healthy controls (HC; n = 210) were isolated, and the presence of HLA-B*51 or HLA-B*52 was screened for by using PCR with sequence-specific primers. RESULTS: We found a significant association of HLA-B*52 with TAK (20.9% vs HC = 6.7%, P = 0.000, OR = 3.7, 95% CI = 2.02 to 6.77). The distribution of HLA-B*51 did not differ between TAK patients and HCs (22.7% vs 24.8%, OR = 0.9, 95% CI = 0.60 to 1.34). The presence of HLA-B*52 decreased in late-onset patients (> 40 years of age; 12.0%, P = 0.024, OR = 0.43, 95% CI = 0.20 to 0.91). Patients with angiographic type I disease with limited aortic involvement also had a lower presence of HLA-B*52 compared to those with all other disease subtypes (13.1% vs 26%, P = 0.005, OR = 0.43, 95% CI = 0.23 to 0.78). CONCLUSIONS: In this study, the previously reported association of TAK with HLA-B*52 in other populations was confirmed in patients from Turkey. The functional relevance of HLA-B*52 in TAK pathogenesis needs to be explored further.