FRI0024 AA AMYLOIDOSIS AND LUNG DISEASES IN RHEUMATOID ARTHRITIS – A POSTMORTEM CLINICOPATHOLOGIC STUDY OF 147 PATIENTS
Authors: Ágnes Apáthy, Miklós Bély
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Systemic AA amyloidosis (<b>AAa</b>) is one of the most important complications of rheumatoid arthritis (<b>RA</b>) [1]. A wide spectrum of lung diseases may complicate <b>RA</b> or associate with <b>RA</b> [2-4]. <h3>Objectives</h3> The <b>aim</b> of this study was to determine the influence of <b>AAa</b> on lung diseases related or not related to <b>RA</b>. <h3>Methods</h3> We studied <b>161</b> random autopsy patients with <b>RA</b> [1]. <b>RA</b> was confirmed clinically according to the criteria of the <b>ARA</b> [5]. Tissue samples of the lungs were available for histological evaluation of <b>147</b> patients. The prevalence of <b>AAa</b> and of distinctly different forms of multifocal inflammation, such as purulent bronchitis and bronchiolitis (<b>purBr</b>) or bronchopneumonia (<b>BrPn</b>), infarct with pneumonia (<b>InfPn</b>), occlusive pneumonia (<b>OcclPn</b> – focal pneumonia caused by compressive peribronchial nodular lymphoid hyperplasia or bronchial blockage by a necrotic nodule) were examined. In addition, rheumatoid pneumonia (<b>RhPn</b>), furthermore interstitial pneumonia (<b>IPn</b>) [1-4] were determined at autopsy and confirmed in a detailed review of extensive histological material. The possible role of <b>AAa</b> on the prevalence of <b>purBr</b> or <b>BrPn</b>, <b>InfPn</b>, <b>OcclPn</b>, <b>RhPn</b> and <b>IPn</b> was analyzed with Pearson's chi-squared (χ<sup>2</sup>) test. <h3>Results</h3> <b>AAa</b> complicated <b>RA</b> in <b>34</b> (<b>23.13</b>%) of 147 patients. Pulmonary blood vessels of different caliber and various tissue structures of the lungs were involved in <b>25</b> (<b>73.53</b>% of 34) cases; the lungs were not involved by <b>AAa</b> in <b>9</b> (<b>26.47</b>% of 34) cases. <b>purBr</b> or <b>BrPn</b> were associated with <b>RA</b> in <b>19</b> (<b>21.1</b>%), <b>InfPn</b> in <b>5</b> (<b>3.4</b>%), <b>OcclPn</b> in <b>2</b> (<b>1.4</b>%), <b>RhPn</b> in <b>3</b> (<b>2.1</b>%) of <b>147</b> patients (only the fatal cases were considered). <b>IPn</b> – characterized by interstitial cellular infiltration with or without edema, fibrinoid deposition, with or without fibrosis, and with or without corresponding pleuritis was present in <b>35</b> (<b>23.8</b>%) of 147 patients; <b>IPn</b> alone was not fatal in our cohort and contributed to the death only in association with cardiac, circulatory or cardio-respiratory insufficiency. Pulmonary amyloid A deposition (<b>n=25</b>) was associated with <b>purBr</b> or <b>BrPn</b> in <b>1</b> (<b>5.26</b>%) of 19, <b>InfPn</b> in <b>1</b> (<b>20.0</b>%) of 5, <b>OcclPn</b> in <b>2</b> (<b>100.0</b>%) of 2, <b>RhPn</b> in <b>none</b> (<b>0.0</b>%) of 3, <b>IPn</b> in <b>12</b> (<b>34.29</b>%) of 35 patients. The relationship between pulmonary <b>AAa</b> and <b>purBr</b> or <b>BrPn</b> (χ=1.2836, p&lt;0.25), <b>InPn</b> (χ=0.1800, p&lt;0.67) or <b>RhPn</b> (χ=0.00025, p&lt;0.98) was not significant. There was a <b>significant</b> and <b>positive correlation</b> between pulmonary <b>AAa</b> and <b>OcclPn</b> (χ=4.8313, p&lt;0.02) or between <b>AAa</b> and <b>lPn</b> (χ=9.7106, p&lt;0.0018). <h3>Conclusion</h3> The main complications of <b>RA,</b> such as <b>AAa</b>, may influence the prevalence, clinical course and symptoms of associated diseases and vice versa. Knowledge of these relationships is important to estimate the relative danger they potentially represent. The <b>significant correlation</b> between <b>AAa</b> and <b>OcclPn</b> or <b>IPn</b> suggests a positive influence of pulmonary amyloid A deposition on <b>OcclPn</b> or <b>lPn</b>. The statistically not significant correlations suggest that <b>purBr</b> or <b>BrPn</b>, <b>InPn</b> and <b>RhPn</b> are independent entities which are not influenced by <b>AAa</b>. <h3>References</h3> [1] Bély M, Apáthy Ágnes: Clinical pathology of rheumatoid arthritis. pp 1-440, Akadémiai Kiadó, Budapest 2012 http://www.akkrt.hu [2] Wright GP, Heard BE: The lungs in rheumatoid arthritis. In Symmers Systemic pathology, ch. 7, pp 370-371, Churcill Livingstone, Edinburgh, London, New York 1976 [3] Bély M, Apáthy Á: Acta Morphologica Hungarica, 1991, 39: 117-156. [4] Bély M: Zentralblatt für allgemeine Pathologie und pathologische Anatomie, 1988, 134: 647-664. [5] Arnett FC, et al: Arthritis Rheum. 1988; 3:315-24, DOI: 10.1002/art.1780310302 <h3>Disclosure of Interests</h3> None declared