SAT0247 PREDICTORS OF ADVERSE OUTCOMES IN DIFFUSE ALVEOLAR HEMORRHAGE OF IMMUNE AND NON-IMMUNE CAUSES: 12-YEAR EXPERIENCE FROM A UNIVERSITY HOSPITAL
Authors: A. Bhushan, D. Choi, G. Maresh, A. Deodhar
Journal: Annals of the Rheumatic Diseases (2020)

Background: Diffuse alveolar hemorrhage (DAH) is a rare, life-threatening condition that has either immune or non-immune etiologies1. DAH caused by capillaritis can be immune-mediated (IM-DAH), e.g. anti-neutrophil cytoplasmic antibody (ANCA) vasculitis and systemic lupus erythematosus, but DAH may also result from anticoagulation, heart failure, drugs or inhaled toxins. Since IM-DAH has specific therapies available, we hypothesized that patients with IM-DAH would have a better prognosis. Objectives: We did a retrospective analysis of all DAH cases seen at our university hospital in the last 12 years to investigate the predictors of adverse outcomes. Methods: Using Epic radiant and Agfa Radiology Information System databases, we queried electronic medical records of all patients admitted to our university between Jan 2007 to Jan 2019 who had the words “diffuse alveolar hemorrhage” in their chest x-ray report. We manually reviewed charts of all these patients to confirm true DAH. True DAH was defined as suspicion of DAH on chest x-ray plus inclusion of DAH on the discharge problem list. We did a detailed chart review of true DAH cases to extract information regarding demographics, baseline disease characteristics, physical/serology/imaging findings, treatment received, and outcomes. The outcomes of interest were death, intubation, shock, need for hemodialysis (HD), and red blood cell transfusions. We compared IM-DAH with non IM-DAH cases using descriptive statistics, t-test, and chi-squared tests. We used logistic regression models to assess the influence of baseline characteristics on outcomes. A p-value &lt; 0.05 was considered statistically significant. Results: There were 88 cases of DAH (M:F 54:34, median age 57) fulfilling inclusion criteria (Table 1). The non-immune etiology was diagnosed in 63%, while 36% were IM-DAH (18% ANCA associated, 9% SLE, 2% decompensated heart failure, the rest were others). No clear etiology for DAH was found in 37.5% cases. Death within 90 days of onset of DAH occurred in 37.5%, 5.6% had recurrent DAH, and 56.8% had sustained remission. Non-IM DAH cases had worse outcomes such as death and were less likely to experience sustained remission (Chi-squared = 19.1, p &lt; 0.001), though IM-DAH were more likely to receive HD (Chi-squared = 7.5, p-value 0.01). Presence of extrapulmonary findings (e.g. nephritis) was a risk factor for adverse outcome, and was statistically significantly correlated with the amount of blood products received, need for HD and likelihood of death, which did not reach statistical significance. Shock and intubation were associated with a higher likelihood of death (p = 0.02 and p = 0.001, respectively). Table 1. Comparison of Clinical Characteristics of Immune versus Non-Immune Cases of Diffuse Alveolar Hemorrhage Variable Immune cases (N = 32) Non-immune cases (N = 56) Statistical comparison Age (years) 51.09 55.91 P = 0.196 %Female 43.8 35.7 P = 0.510 %presenting with hemoptysis 8 (25%) 14 (25%) P = 0.101 %extrapulmonary findings 20 (62.5%) 1 (1.7%) P = 6.9*e -10 pANCA positive 16 (50%) 2 (3.6%) P = 0.0004 % on anticoagulation 9.4 2.5 P = 0.090 Mean Creatinine 2.38 1.89 P = 0.507 Mean hospital length of stay (days) 16.69 23.27 P = 0.139 Drop in Hemoglobin prior to DAH and day of DAH 0.24 1.17 P = 0.070 %Bronchoscopy-confirmed DAH 62.5 75.0 P = 0694 Mean units of blood transfused 1.91 2.66 P = 0.448 %Need for hemodialysis 37.5 12.5 P = 0.010 %Shock (any kind) 21.9 32.1 P = 0.338 %Need for intubation 43.8 62.5 P = 0.122 %Death within 90 days 12.5 52.7 P = 0.0009 Conclusion: DAH, a life-threatening condition, has both immune and non-immune etiologies. Our 12-years, single-center, university hospital experience showed that IM-DAH has a better prognosis than non IM-DAH. Presence of extrapulmonary manifestations was associated with worse outcomes. References: [1] Moo Suk Park. Diffuse Alveolar Hemorrhage. Tuberc Respir Dis (Seoul). 2013 Apr; 74(4): 151–162. [2] Nasser M, Cottin V. Alveolar Hemorrhage in Vasculitis (Primary and Secondary). Semin Respir Crit Care Med. 2018 Aug;39(4):482-493. Disclosure of Interests: Ambika Bhushan: None declared, Dongseok Choi: None declared, Guy Maresh: None declared, Atul Deodhar Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB