Lehn Weaver, MD, PhD

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Lehn Weaver, MD, PhD, is an attending physician in the Division of Rheumatology at Children's Hospital of Philadelphia.

Areas of Expertise: Rare rheumatic diseases and autoinflammatory syndromes
Locations: Main Hospital


Lehn Weaver, MD, PhD, completed his medical training and doctoral degree in Immunology at Dartmouth Medical School before joining Children's Hospital of Philadelphia to complete his internship and residency in General Pediatrics. He continued his training at Children's Hospital of Philadelphia as a fellow and junior faculty member within the Division of Pediatric Rheumatology. During his training, Dr. Weaver studied basic mechanisms of inflammation in models of rheumatic diseases including lupus, psoriasis and arthritis. He has a particular interest in rare rheumatic diseases and autoinflammatory syndromes, and currently cares for numerous children and young adults with a wide variety of musculoskeletal, inflammatory and rheumatic diseases in the Pediatric Rheumatology clinic at Children's Hospital of Philadelphia.

Education and Training

Medical School

MD - Dartmouth Medical School, Hanover, NH


Pediatrics - The Children's Hospital of Philadelphia, Philadelphia PA


Pediatric Rheumatology - The Children's Hospital of Philadelphia, Philadelphia PA

Board Certification

Pediatric Rheumatology – American Board of Pediatrics
Pediatrics – American Board of Pediatrics

Graduate Degree

PhD in Immunology - Dartmouth College, Hanover, NH

Titles and Academic Titles

Attending Physician

Departments and Services




Weaver LK, Chu N, Behrens EM. Toll-like receptor 9 activation potentiates interferon-γ-mediated immunopathology in a murine model of Macrophage Activation Syndrome. Arthritis Rheumatol. 2018 Aug 2. doi: 10.1002/art.40683. [Epub ahead of print]


Weaver LK, Behrens EM. Weathering the Storm: Improving Therapeutic Interventions for Cytokine Storm Syndromes by Targeting Disease Pathogenesis. Curr Treatm Opt Rheumatol. 2017 Mar;3(1):33-48. doi: 10.1007/s40674-017-0059-x. Epub 2017 Feb 7.

Weaver LK. Combining multiple biomarkers differentiates between active sJIA, sJIA-MAS, and EBV-HLH. Clin Exp Immunol. 2018 Mar;191(3):253-254. doi: 10.1111/cei.13063. Epub 2017 Oct 26.


Weaver LK, Chu N, Behrens EM. TLR9-mediated inflammation drives a Ccr2-independent peripheral monocytopoiesis through enhanced extramedullary monocytopoiesis. Proc Natl Acad Sci U S A. 2016 Sep 27;113(39):10944-9. doi: 10.1073/pnas.1524487113. Epub 2016 Sep 12.

Rood JE, Canna SW, Weaver LK, Tobias JW, Behrens EM. IL-10 distinguishes a unique population of activated, effector-like CD8+ T cells in murine acute liver inflammation. J Leukoc Biol. 2017 Apr;101(4):1037-1044. doi: 10.1189/jlb.3A0916-221RR. Epub 2016 Dec 29.


Minoia F, Davì S, Horne A, Bovis F, Demirkaya E, Akikusa J, Ayaz NA, Al-Mayouf S, Barone P, Bica B, Bolt I, Breda L, De Cunto C, Enciso S, Gallizzi R, Griffin T, Hennon T, Horneff G, Jeng M, Kapovic AM, Lipton JM, Magni-Manzoni S, Rumba I, Magalhaes CS, Sewairi WM, Stine KC, Vougiouka O, Weaver LK, Davidsone Z, De Inocencio J, Ioseliani M, Lattanzi B, Tezer H, Buoncompagni A, Picco P, Ruperto N, Martini A, Cron RQ, and Ravelli A. (2014). Dissecting the heterogeneity of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis. The Journal of Rheumatology.


Weaver LK, Behrens EM. (2014). Hyperinflammation, rather than hemophagocytosis, is the common link between Macrophage Activation Syndrome and Hemophagocytic Lymphohistiocytosis. Current Opinion Rheumatology. 26(5):562-9.


Costa-Reis P, Weaver LK, Behrens EM, Sullivan KE. (2013). Chronic Recurrent Multifocal Osteomyelitis in a Patient with Common Variable Immunodeficiency. Joint Bone Spine. 81(2):193-194.

Weaver LK, Behrens EM. (2013). How to use… antinuclear antibodies in paediatric rheumatic diseases. Archives of Disease in Childhood. 98:64-70.


Pioli PA, Jensen AL, Weaver LK, Amiel E, Shen Z, Shen L, Wira CR, Guyre PM. (2007).  Estradiol attenuates lipopolysaccharide-induced CXC chemokine ligand 8 production by human peripheral blood monocytes.  Journal of Immunology.  Nov 1; 179(9):6284-6290.

Fabriek BO, Polfliet MM, Vloet RP, van der Schors RC, Ligtenberg AJ, Weaver LK, Geest C, Matsuno K, Moestrup SK, Dijkstra CD, van den Berg TK.  (2007). The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor.  Blood. Jun 15; 109(12):5223-5229.

Weaver LK, Pioli PA, Wardwell K, Vogel SN, Guyre PM. (2007).  Up-regulation of human monocyte CD163 upon activation of cell-surface Toll-like receptors. The Journal of Leukocyte Biology. Mar; 81(3):663-671.


Weaver LK, Hintz-Goldstein, KA, Pioli PA, Wardwell K, Vogel SN, Qureshi N, and Guyre PM. (2006). Activation of Cell Surface Toll-like Receptors Causes Shedding of the Hemoglobin Scavenger Receptor CD163. The Journal of Leukocyte Biology. Jul;80(1):26-35.  (“Pivotal Advance” and Cover Article)

Pioli PA, Weaver LK, Schaefer TM, Wright JA, Wira CR, and Guyre PM. (2006). Lipopolysaccharide-induced IL-1 beta production by human uterine macrophages up-regulates uterine epithelial cell expression of human beta-defensin 2. Journal of Immunology. 176(11):6647-6655.


O'Connor BP, Raman VS, Erickson LD, Cook WJ, Weaver LK, Ahonen C, Lin LL, Mantchev GT, Bram RJ, and Noelle RJ. (2004). BCMA is essential for the survival of long-lived bone marrow plasma cells. J Exp Med 199, 91-8.




Weaver LK.  Myeloid cells in the immunopathogenesis of cytokine storm syndromes.  In: Behrens EM and Cron RQ (Ed.)  Cytokine Storm Syndromes.  Springer. 2019.


Weaver LK, Weiss, PF. (2016). Henoch-Schönlein Purpura. In Parnham MJ (ed.) Compendium of Inflammatory Diseases. Springer Basel. pp 576-584. DOI 10.1007/978-3-7643-8550-7_199.

Posters and Presentations


Weaver LK, Minichino D, Biswas C, Chu N, Albeituni S, Nichols KE, and Behrens EM. (2017). Host microbiota prime Jak signaling in myeloid progenitors to support TLR-enhanced myelopoiesis and MAS immunopathology. Next-Gen Therapies in SJIA & MAS. Washington, DC.

Invited Lectures


Weaver LK. Invited lecturer for the Department of Microbiology and Immunology at Thomas Jefferson University.  Philadelphia, PA.  “Microbiota-dependent myelopoiesis fuels chronic inflammation.” 2018.


Weaver LK. Invited speaker for the Next-Gen Therapies in SJIA & MAS.  “Antibiotic-treated mice are protected from TLR9-MAS.” Washington, DC. 2017.

Weaver LK. Invited lecturer for the Child Health Institute of New Jersey Research Seminar.  New Brunswick, NJ.  “Microbiota-dependent myelopoiesis fuels chronic inflammation.” 2017.

Weaver LK. Invited lecturer for Robert Wood Johnson Medical School Pediatric Grand Rounds.  New Brunswick, NJ.  “Feed-forward inflammatory loops: Mechanisms of cytokine storm pathogenesis in Sepsis, MAS, and HLH.” 2017.

Weaver LK. Invited lecturer for Northwestern Rheumatology Grand Rounds.  Chicago, IL.  “Microbiota-dependent myelopoiesis fuels chronic inflammation.” 2017.

Weaver LK. Invited lecturer for the UCLA I3T Seminar Series.  Los Angeles, CA.  “Microbiota-dependent myelopoiesis fuels chronic inflammation.” 2017.

Weaver LK. Selected oral Plenary Abstract Presentation, Pediatric Rheumatology Symposium, Houston, TX, “Microbiota-Dependent Signals Regulate Inflammatory Myelopoiesis in a Murine Model of Macrophage Activation Syndrome.” 2017.

Awards and Honors

2017, PennCHOP Microbiome Pilot and Feasibility Award
2015, CHOP Research Poster Day Award
2015, Rheumatology Research Foundation Scientist Development Award
2014, ACR Pediatric Research Award
2014, Best Basic Science Abstract by a Fellow-in-Training, PRYSM 2014
2014, PRYSM Fellow-in-Training Travel Award
2012-2013, Amgen/Pfizer Rheumatology Fellowship Training Award
2011, American College of Rheumatology Fellow-in-Training Scholarship
2010, The Children's Hospital of Philadelphia Travel Award for the ACR Meeting
2009, American College of Rheumatology Resident Award
2009, Thomas Almy DMS Chapter of the Gold Humanism in Medicine Honor Society
2009, New Hampshire Pediatric Society Award

Editorial and Academic Positions

Editorial positions


2017-present, Frontiers in Immunology (Specialty: Autoimmunity and Autoinflammatory Diseases), Review Editor of the Editorial Board

Ad-Hoc Reviewer

2018-present, Arthritis Research & Therapy
2017-present, Clinical & Experimental Immunology
2017-present, BMJ Case Reports
2016-present, Arthritis & Rheumatology
2016-present, Current Pediatrics Research
2015-present, International Immunopharmacology
2011-present, Journal of Leukocyte Biology
2011-present, Pediatric Rheumatology On-line Journal

Academic and Institutional Committees

2015-present, Rheumatology Website Design Committee
2015-present, Pediatric Rheumatology Scientific Review Committee

Leadership and Memberships

Memberships in Professional Organizations

2011-present, American College of Rheumatology