title: Usefulness of pleural effusion antinuclear antibodies in the diagnosis of lupus pleuritis.
abstract: We performed this study to determine sensitivity and specificity of pleural effusion antinuclear antibodies (ANA) at a titer of ≥1 : 160, and the ratio of pleural effusion to serum ANA of ≥1, to distinguish between pleural fluid from lupus pleuritis and other causes. A prospective study of 54 patients with pleural effusion (12 lupus pleuritis, seven parapneumonic effusion, 26 malignancy-associated pleural effusions, nine transudative effusions) was performed. ANA at a titer of ≥1 : 160 were found in 11 of 12 lupus pleuritis samples, and in four of 42 pleural effusions from non-systemic lupus erythematosus (SLE) patients. The pleural effusion ANA at a titer of ≥1 : 160 gave a sensitivity of 91.67% for lupus pleuritis, with a specificity of 83.33% when compared with all other pleural effusions, 90.91% when compared with exudative effusion (parapneumonic effusion and malignancy-associated effusion) and 55.56% when compared with the transudative pleural effusion group. Using the ratio of pleural effusion to serum ANA of ≥1, the sensitivity and the specificity decreased to 75.00% and 78.57%, respectively. This study provides further evidence that the pleural effusion ANA at a titer of ≥1 : 160 is a sensitive and specific diagnostic biomarker for lupus pleuritis in patients with lupus. However, pleural effusion ANA can occasionally be found in other conditions.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: C
authors.initials: C
authors.lastname: Toworakul
authors.forename: N
authors.initials: N
authors.lastname: Kasitanon
authors.forename: W
authors.initials: W
authors.lastname: Sukitawut
authors.forename: R
authors.initials: R
authors.lastname: Wichinun
authors.forename: W
authors.initials: W
authors.lastname: Louthrenoo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000032:analysis* / Q000097:blood; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000276:immunology*; D010998:Pleurisy / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear