LAUSR

Background Systemic AA amyloidosis (AAa) is one of the most important complications of rheumatoid arthritis (RA) [1]. A wide spectrum of lung diseases may complicate RA or associate with RA [2-4]. Objectives The aim of this study was to determine the influence of AAa on lung diseases related or not related to RA. Methods We studied 161 random autopsy patients with RA [1]. RA was confirmed clinically according to the criteria of the ARA [5]. Tissue samples of the lungs were available for histological evaluation of 147 patients. The prevalence of AAa and of distinctly different forms of multifocal inflammation, such as purulent bronchitis and bronchiolitis (purBr) or bronchopneumonia (BrPn), infarct with pneumonia (InfPn), occlusive pneumonia (OcclPn – focal pneumonia caused by compressive peribronchial nodular lymphoid hyperplasia or bronchial blockage by a necrotic nodule) were examined. In addition, rheumatoid pneumonia (RhPn), furthermore interstitial pneumonia (IPn) [1-4] were determined at autopsy and confirmed in a detailed review of extensive histological material. The possible role of AAa on the prevalence of purBr or BrPn, InfPn, OcclPn, RhPn and IPn was analyzed with Pearson’s chi-squared (χ 2) test. Results AAa complicated RA in 34 (23.13%) of 147 patients. Pulmonary blood vessels of different caliber and various tissue structures of the lungs were involved in 25 (73.53% of 34) cases; the lungs were not involved by AAa in 9 (26.47% of 34) cases. purBr or BrPn were associated with RA in 19 (21.1%), InfPn in 5 (3.4%), OcclPn in 2 (1.4%), RhPn in 3 (2.1%) of 147 patients (only the fatal cases were considered). IPn – characterized by interstitial cellular infiltration with or without edema, fibrinoid deposition, with or without fibrosis, and with or without corresponding pleuritis was present in 35 (23.8%) of 147 patients; IPn 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 (n=25) was associated with purBr or BrPn in 1 (5.26%) of 19, InfPn in 1 (20.0%) of 5, OcclPn in 2 (100.0%) of 2, RhPn in none (0.0%) of 3, IPn in 12 (34.29%) of 35 patients. The relationship between pulmonary AAa and purBr or BrPn (χ=1.2836, p<0.25), InPn (χ=0.1800, p<0.67) or RhPn (χ=0.00025, p<0.98) was not significant. There was a significant and positive correlation between pulmonary AAa and OcclPn (χ=4.8313, p<0.02) or between AAa and lPn (χ=9.7106, p<0.0018). Conclusion The main complications of RA, such as AAa, 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 significant correlation between AAa and OcclPn or IPn suggests a positive influence of pulmonary amyloid A deposition on OcclPn or lPn. The statistically not significant correlations suggest that purBr or BrPn, InPn and RhPn are independent entities which are not influenced by AAa. References [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 Disclosure of Interests None declared