PULMONARY RHEUMATOID NODULES: DOES SEROLOGIC STATUS MATTER?

BackgroundThe frequency of pulmonary rheumatoid nodules closely relates to the diagnostic modality and changes from <0.4% to 32%. Also, it is known that seropositive RA patients tend to have more extra-articular disease.ObjectivesWe aimed to compare the disease and pulmonary rheumatoid nodule characteristics of seropositive and seronegative RA patients.MethodsIn this study, all RA patients - according to ICD-10 code - and had at least one chest computerized tomography (CT) were examined and revealed 4117 individual patients. First, RA diagnosis was confirmed according the patients’ history, physical examination, radiography and laboratory assessment. Then, chest CTs were examined by an experienced radiologist. To classify pulmonary nodules as ‘’pulmonary rheumatoid nodule’’, following inclusion and exclusion criteria were used; For inclusion: 1) nodules with changing dimension on follow-up, 2) At least two nodules with different dimensions, 3) Cavitary nodule at any chest CT. For exclusion: 1) Solitary nodules OR all nodules ≤ 5mm and without follow-up OR no change on follow-up. Biggest nodule was named as dominant nodule. Then, patients were grouped according to rheumatoid factor and anti-CCP status as seropositive (RF ± anti-CCP) and seronegative. Demographics, comorbidities, RA-spesific treatments and nodule characteristics were compared.ResultsOf 680 RA patients who had pulmonary nodule in chest CT, 208 (30.6%) patients were classified as having pulmonary rheumatoid nodule. 167 (80.3%) patients were seropositive. Demographic and comorbidity characteristics were similar among seronegative and seropositive patients (Table 1). Regarding RA-spesific treatments, methotrexate, leflunomide and rituximab were prescribed more frequently in seropositive patients. For nodule characteristics, seropositive patients had higher number of nodules (5 [1-48] vs 3 [1-27]; p=0.004), bigger dominant nodule (8 [3-95] vs 6 [3-45] mm; p=0.011), and higher percentage of cavitary nodule (28.7% vs 12.2%; p=0.03). Localization of the nodule was compareble.Table 1.Comparison of demographic, disease and nodule characteristics of seropositive and seronegative patients (n=208)Seropositive (n=167, 80.3%)Seronegative (n=41, 19.7%)P valueFemale, n(%)113 (67.7)28 (68.3)0.94Age at the time of CT (median, min-max)61 (24-83)59.7 (20-83)0.28Smoking (n=73)26 (43.3)4 (30.8)0.40- Never smoked34 (56.7)9 (69.2)- Ever smokedComorbidity (n=188)127 (84.7)30 (78.9)0.40- Hypertension72 (55.0)18 (58.1)0.91- Diabetes (n=166)25 (18.5)7 (22.6)0.79- CAD (n=165)30 (22.6)7 (21.9)0.93- Heart Failure (n=164)15 (11.4)6 (18.8)0.41- COPD (n=163)20 (15.2)1 (3.2)0.13- Asthma (n=160)15 (11.6)5 (16.1)0.54- CKD (n=169)20 (14.5)8 (25.8)0.22- ILD (n=202)54 (33.1)10 (25.6)0.37RA-spesific treatments (ever)90 (72.6)16 (55.2)0.07- Methotrexate (n=153)105 (64.0)12 (30.8)0.001- Leflunomide (n=208)117 (70.5)25 (61.0)0.06- Hydroxchloroquine (n=169)65 (47.4)11 (36.7)0.28- Sulfasalazine (n=167)39 (39.0)6 (27.3)0.30- TNFi (n=122)41 (39.8)2 (9.5)0.008- Rituximab (n=124)11 (9.9)2 (8.0)0.77- Tofacitinib (n=136)12 (11.9)2 (10.5)0.86- Abatacept (n=120)9 (8.5)2 (8.7)0.98- Tocilizumab (n=129)Number of nodules at baseline CT (median, min-max)5 (1-48)3 (1-27)0.004Diameter of dominant nodule (median, min-max) (mm)8 (3-95)6 (3-45)0.011Localization of dominant nodul64 (38.3)15 (36.6)0.84- Left or right?64 (38.3)12 (29.3)0.48◦ Left51 (30.5)16 (39.0)0.28- Upper, middle or lower?52 (31.1)13 (31.7)◦ Upper69 (41.3)21 (51.2)◦ Middle22 (13.2)7 (17.1)◦ Lower76 (45.5)13 (31.7)-Peripheral, central or subpleural◦ Peripheral◦ Central◦ SubpleuralCavitation48 (28.7)5 (12.2)0.03Calcification54 (32.5)12 (29.3)0.69CAD: Coronary artery disease, CKD: Chronic kidney disease,; ILD: Interstitial Lung Disaese,ConclusionAutoantibodies seem to have impact on the characteristics of pulmonary rheumatoid nodules. As there were different prescription patterns were seen in our study, effects of these treatment differences need to be determined.ReferencesDisclosure of InterestsNone declared