Date: Sunday, November 8, 2020
Session Type: Abstract Session
Session Time: 4:00PM-4:50PM
Background/Purpose: Rapid identification of HLH/MAS coupled with a multidisciplinary approach to management is essential to improve patient outcomes. We describe our experience with a newly instituted Evidence Based Guideline (EBG) for HLH/MAS at Boston Children’s Hospital (BCH).
Methods: A diagnostic and therapeutic algorithm for HLH/MAS was developed at BCH based on literature review and expert opinion. This EBG was activated in 1/2018 with the goal to review quality metrics after implementation. An electronic medical record search algorithm (patients with an oncology and/or rheumatology note, fever ≥38.2oC, and ferritin ≥500 ng/mL) was developed to retrospectively identify all hospitalized patients in the EBG from 1/2018-4/2019. For comparison, patients with HLH/MAS treated at BCH before implementation of the EBG (3/2016-4/2018) were identified with the same search algorithm. The selected medical records were reviewed by an attending rheumatologist to confirm the HLH/MAS diagnosis and collect clinical data. Subjects with a previously known diagnosis of HLH/MAS before hospitalization were excluded.
Results: After initiation of the EBG, 12 girls and 15 boys with an average age of 8.8 years were identified by house staff as potential HLH/MAS patients and rheumatology was consulted for management. After rheumatology consult, 10 patients were diagnosed with HLH/MAS by the treating team. Of these, 6 met HLH 2004 criteria, and 9 met 2016 MAS classification criteria for systemic juvenile idiopathic arthritis (sJIA). In the comparison group, 20 patients were identified as having HLH/MAS prior to the start of the EBG (pre-EBG). Fifteen pre-EBG patients were diagnosed with HLH/MAS by the treating team during the hospital admission and 5 were identified during retrospective chart review by the study team. The 20 pre-EBG patients had an average age of 8.9 years (9 boys, 11 girls). Of these patients, 7 met HLH 2004 criteria and 18 met 2016 MAS classification criteria for sJIA.
The mean time to HLH/MAS diagnosis by the treating team was 8.4 days in the pre-EBG group at 2.8 days in the post-EBG group. The average hospital stay among pre-EBG patients was 34.0 days with a mean time to HLH/MAS directed treatment of 7.4 days. The same metrics in the post-EBG group were 29.9 days and 3.1 days, respectively. The most common first line treatments for both groups (pre-EBG, post-EBG) were IVIG (35.0%, 53.3%), Anakinra (30.0%, 20.0%), and glucocorticoids (15.0%, 20.0%). 30.0% of pre-EBG patients responded completely to first line treatment, compared to 40.0% post-EBG. The mortality rate during hospitalization was 25.0% in the pre-EBG group and 6.7% in the post-EBG group.
Conclusion: Implementation of an EBG for HLH/MAS was associated with superior outcomes in the post-EBG cohort compared to patients treated before the EBG was established. Notably, overall survival increased from 75.0% in the pre-EBG group to 93.3% in the post-EBG group. While improvements may be partially attributed to increased recognition and advances in treatment of HLH/MAS that have accumulated over time, this analysis also suggests that a multidisciplinary treatment pathway for HLH/MAS contributed to favorable outcomes.
To cite this abstract in AMA style:Hoyt K, Halyabar O, Han J, Case S, Chang M, Platt C, Cohen E, Day-Lewis M, Dedeoglu F, Hausmann J, Janssen E, Lee P, Lo J, Priebe G, Lo M, Meidan E, Nigrovic P, Roberts J, Son M, Sundel R, Gorman M, Degar B, Hazen M, Henderson L. Outcomes of an Evidence Based Guideline for the Treatment of Hemophagocytic Lymphohistiocytosis and Macrophage Activation Syndrome [abstract]. Arthritis Rheumatol. 2020; 72 (suppl 10). https://acrabstracts.org/abstract/outcomes-of-an-evidence-based-guideline-for-the-treatment-of-hemophagocytic-lymphohistiocytosis-and-macrophage-activation-syndrome-2/. Accessed September 16, 2021.
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