Ryanne Ashley Brown, MD, MBA

All Publications

• Clonal replacement of tumor-specific T cells following PD-1 blockade. Nature medicine Yost, K. E., Satpathy, A. T., Wells, D. K., Qi, Y., Wang, C., Kageyama, R., McNamara, K. L., Granja, J. M., Sarin, K. Y., Brown, R. A., Gupta, R. K., Curtis, C., Bucktrout, S. L., Davis, M. M., Chang, A. L., Chang, H. Y. 2019

  Abstract

  Immunotherapies that block inhibitory checkpoint receptors on T cells have transformed the clinical care of patients with cancer1. However, whether the T cell response to checkpoint blockade relies on reinvigoration of pre-existing tumor-infiltrating lymphocytes or on recruitment of novel T cells remains unclear2-4. Here we performed paired single-cell RNA and T cell receptor sequencing on 79,046 cells from site-matched tumors from patients with basal or squamous cell carcinoma before and after anti-PD-1 therapy. Tracking T cell receptor clones and transcriptional phenotypes revealed coupling of tumor recognition, clonal expansion and T cell dysfunction marked by clonal expansion of CD8+CD39+ T cells, which co-expressed markers of chronic T cell activation and exhaustion. However, the expansion of T cell clones did not derive from pre-existing tumor-infiltrating T lymphocytes; instead, the expanded clones consisted of novel clonotypes that had not previously been observed in the same tumor. Clonal replacement of T cells was preferentially observed in exhausted CD8+ T cells and evident in patients with basal or squamous cell carcinoma. These results demonstrate that pre-existing tumor-specific T cells may have limited reinvigoration capacity, and that the T cell response to checkpoint blockade derives from a distinct repertoire of T cell clones that may have just recently entered the tumor.

  View details for DOI 10.1038/s41591-019-0522-3

  View details for PubMedID 31359002

• A Case Report of Pediatric Clear Cell Carcinoma of the Urinary Bladder Associated With Polyomavirus AJSP-REVIEWS AND REPORTS Saleem, A., Brown, R. A., Higgins, J. T., Troxell, M. L., Kunder, C. A., Pinsky, B. A., Zambrano, E., Kao, C. 2018; 23 (6): 291–95

  View details for DOI 10.1097/PCR.0000000000000284

  View details for Web of Science ID 000457629000012

• Orbital and chorioretinal manifestations of Erdheim-Chester disease treated with vemurafenib. American journal of ophthalmology case reports Huang, L. C., Topping, K. L., Gratzinger, D., Brown, R. A., Martin, B. A., Silva, R. A., Kossler, A. L. 2018; 11: 158–63

  Abstract

  Purpose: We report a patient with severe multi-organ dysfunction of unknown origin who presented with bilateral orbital and chorioretinal manifestations that led to the diagnosis of Erdheim-Chester Disease (ECD).Observations: ECD is a rare, histiocytic, proliferative disorder characterized by multi-systemic organ involvement that has historically lacked effective therapy. Our patient underwent genetic testing that was positive for the BRAF V600E mutation; therefore, the patient was treated with vemurafenib.Conclusions and importance: This case demonstrates the rare orbital and intraocular manifestations of ECD and the unfortunate impact of a delayed diagnosis, the importance of early gene therapy testing for management decisions, and the utilization of targeted directed therapy to improve visual outcomes and quality of life.

  View details for PubMedID 30094395

• Loss of PERP as a Diagnostic Biomarker for Differentiated Vulvar Intraepithelial Neoplasia (dVIN) Devereaux, K., Brown, R., Barry-Holson, K., Yang, E., Kong, C. NATURE PUBLISHING GROUP. 2018: 416–17

  View details for Web of Science ID 000429308603037

• Expression of the transcription factor ZBTB46 distinguishes human histiocytic disorders of classical dendritic cell origin. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc Satpathy, A. T., Brown, R. A., Gomulia, E., Briseño, C. G., Mumbach, M. R., Pan, Z., Murphy, K. M., Natkunam, Y., Chang, H. Y., Kim, J. 2018

  Abstract

  Distinguishing classical dendritic cells from other myeloid cell types is complicated by the shared expression of cell surface markers. ZBTB46 is a zinc finger and BTB domain-containing transcription factor, which is expressed by dendritic cells and committed dendritic cell precursors, but not by plasmacytoid dendritic cells, monocytes, macrophages, or other immune cell populations. In this study, we demonstrate that expression of ZBTB46 identifies human dendritic cell neoplasms. We examined ZBTB46 expression in a range of benign and malignant histiocytic disorders and found that ZBTB46 is able to clearly define the dendritic cell identity of many previously unclassified histiocytic disease subtypes. In particular, all examined cases of Langerhans cell histiocytosis and histiocytic sarcoma expressed ZBTB46, while all cases of blastic plasmacytoid dendritic cell neoplasm, chronic myelomonocytic leukemia, juvenile xanthogranuloma, Rosai-Dorfman disease, and Erdheim-Chester disease failed to demonstrate expression of ZBTB46. Moreover, ZBTB46 expression clarified the identity of diagnostically challenging neoplasms, such as cases of indeterminate cell histiocytosis, classifying a fraction of these entities as dendritic cell malignancies. These findings clarify the lineage origins of human histiocytic disorders and distinguish dendritic cell disorders from all other myeloid neoplasms.

  View details for PubMedID 29743654

• Primary cutaneous anaplastic large cell lymphoma. Journal of cutaneous pathology Brown, R. A., Fernandez-Pol, S., Kim, J. 2017; 44 (6): 570-577

  Abstract

  Primary cutaneous anaplastic large cell lymphoma (PC-ALCL) is a CD30+ lymphoproliferative disorder (LPD) of the skin with a relatively good prognosis in the absence of high-stage disease. CD30+ LPDs comprise approximately 25%-30% of primary cutaneous lymphomas and as a group represent the second most common clonal T-cell neoplasm of the skin behind mycosis fungoides. Diagnosis of PC-ALCL relies strongly on clinicopathologic correlation given the potential morphologic, clinical and molecular overlap with the other cutaneous CD30+ LPD, lymphomatoid papulosis, and more aggressive hematolymphoid neoplasms.

  View details for DOI 10.1111/cup.12937

  View details for PubMedID 28342276

• ETV3-NCOA2 in indeterminate cell histiocytosis: clonal translocation supports sui generis. Blood Brown, R. A., Kwong, B. Y., McCalmont, T. H., Ragsdale, B., Ma, L., Cheung, C., Rieger, K. E., Arber, D. A., Kim, J. 2015

  View details for PubMedID 26438513