Table 1.
Baseline demographic, clinical, and autoantibody profiles of antinuclear antibody (ANA)–positive (presence of any nuclear indirect immunofluorescence [IIF] pattern), anticellular antibody (ACA)–negative (no IIF pattern), and isolated cytoplasmic/mitotic (CMP) groups
| ANA+ | ACA− | Isolated CMP | ||||
|---|---|---|---|---|---|---|
| (n = 1,049) | (n = 71) | (n = 17)† | ANA+ and ACA− | ANA+ and CMP | ACA− and CMP | |
| Demographics | ||||||
| Age at diagnosis, years, mean | 34.7‡ | 40.9‡ | 35.8 | −6.2 (−9.4, −2.9) | −1 (−7.5, 5.4) | 5.1 (−2.4, 12.7) |
| Female, % | 89.7 | 90.1 | 100 | −0.4 (−7.6, 6.7) | −10.3 (−24.8, 4.2) | −9.9 (−24.2, 4.5) |
| Postsecondary education, % | 66.7‡ | 76.1§ | 31.3†* | −9.5 (−20.1, 1.2) | 35.4 (12.5, 58.3) | 44.9 (20, 69.8) |
| Disease duration, years, mean | 0.47 | 0.42 | 0.35 | 0.05 (−0.03, 0.14) | 0.12 (−0.05, 0.29) | 0.07 (−0.12, 0.25) |
| Race/ethnicity, % | ||||||
| Asian | 23.2‡ | 4.2‡ | 11.8 | 19 (13.7, 24.3) | 11.5 (−4.1, 27) | −7.5 (−23.6, 8.5) |
| African descendant | 16.2‡ | 7.0‡ | 5.9 | 9.2 (2.8, 15.5) | 10.3 (−1.1, 21.7) | 1.2 (−11.5, 13.8) |
| Hispanic | 3.4 | 2.8 | 0 | 0.5 (−3.5, 4.5) | 3.4 (−5.2, 11.9) | 2.8 (−1, 6.7) |
| White | 52.4†* | 84.5‡ | 76.5§ | −32.1 (−41.1, −23.2) | −24.1 (−44.5, −3.7) | 8 (−13.8, 29.9) |
| Other | 4.8 | 1.4 | 5.9 | 3.4 (−1.6, 8.4) | −1.1 (−12.3, 10.2) | −4.5 (−16, 7) |
| Smoking status, % | ||||||
| Current smoker | 15.1 | 21.9 | 18.8 | −6.8 (−17.1, 3.6) | −3.7 (−22.9, 15.6) | 3.1 (−18.5, 24.8) |
| Former smoker | 21.1 | 26.6 | 25 | −5.5 (−16.6, 5.6) | −3.9 (−25.3, 17.5) | 1.6 (−22.3, 25.4) |
| High alcohol use, % | 1.5 | 1.5 | 0 | 0 (−3, 3) | 1.5 (−4.6, 7.5) | 1.5 (−4.7, 7.6) |
| Hypertension, % | 32.6‡ | 29.6§ | 58.8†* | 3 (−8, 14) | −26.2 (−49.8, −2.7) | −29.2 (−54.9, −3.6) |
| Nephritis at enrollment, % | 28.7 | 26.6 | 50 | 2.1 (−9, 13.3) | −21.3 (−46, 3.4) | −23.4 (−50.2, 3.3) |
| Proteinuria at enrollment, % | 4.5 | 3.3 | 12.5 | 1.2 (−3.4, 5.9) | −8 (−24.3, 8.3) | −9.2 (−26, 7.6) |
| No. of ACR criteria, mean | 4.8 | 4.7 | 4.7 | 0.1 (−0.1, 0.4) | 0.1 (−0.4, 0.6) | 0 (−0.5, 0.5) |
| SLEDAI-2K score, mean | 5.4‡ | 4.1‡ | 5.4 | 1.3 (0, 2.6) | 0 (−2.7, 2.6) | −1.3 (−3.8, 1.1) |
| Neurological | 0.3 | 0.3 | 0 | −0.1 (−0.5, 0.3) | 0.3 (−0.5, 1) | 0.3 (−0.5, 1.2) |
| Mucocutaneous | 1.1 | 1 | 1.3 | 0.1 (−0.4, 0.5) | −0.1 (−1.1, 0.8) | −0.2 (−1, 0.6) |
| Musculoskeletal | 0.8 | 0.7 | 1.3 | 0.1 (−0.3, 0.5) | −0.4 (−1.3, 0.4) | −0.5 (−1.4, 0.4) |
| Renal | 1.4 | 0.7 | 1.8 | 0.7 (−0.1, 1.5) | −0.4 (−2, 1.2) | −1.1 (−2.5, 0.4) |
| Serositis | 0.1 | 0.1 | 0 | 0 (−0.1, 0.1) | 0.1 (−0.1, 0.3) | 0.1 (−0.2, 0.4) |
| Constitutional | 0 | 0 | 0 | 0 (0, 0.1) | 0 (−0.1, 0.1) | 0 (0, 0.1) |
| Immunologic | 1.6‡ | 1.1‡ | 1.1 | 0.5 (0.1, 0.9) | 0.5 (−0.4, 1.3) | 0 (−0.9, 0.8) |
| Hematologic | 0.1 | 0 | 0 | 0.1 (0, 0.1) | 0.1 (−0.1, 0.3) | 0 (−0.1, 0.1) |
| Medications, % ever used | ||||||
| Glucocorticoids | 80.6 | 74.6 | 82.4 | 6 (−4.4, 16.4) | −1.7 (−20, 16.6) | −7.7 (−28.5, 13.1) |
| High-dose glucocorticoids | 42.3 | 46.5 | 58.8 | −4.2 (−16.1, 7.8) | −16.5 (−40.1, 7.1) | −12.3 (−38.5, 13.8) |
| Antimalarials | 74.3 | 69 | 52.9 | 5.2 (−5.8, 16.3) | 21.3 (−2.6, 45.2) | 16.1 (−10, 42.1) |
| Immunosuppressants | 43.7‡ | 23.9†* | 58.8§ | 19.7 (9.3, 30.1) | −15.2 (−38.7, 8.4) | −34.9 (−60.3, −9.5) |
| Autoantibodies, % | ||||||
| dsDNA | 28.4‡ | 11.3‡ | 17.7 | 17.2 (9.3, 25) | 10.8 (−7.5, 29.1) | −6.4 (−25.9, 13.2) |
| PCNA | 7.3 | 1.4 | 11.8 | 5.9 (−0.2, 12) | −4.4 (−19.8, 11) | −10.4 (−25.9, 5.2) |
| Ribosomal P | 16.1‡ | 5.6‡ | 11.8 | 10.5 (4.7, 16.3) | 4.3 (−11.1, 19.8) | −6.1 (−22.4, 10.1) |
| Ro 52/TRIM21 | 35.9‡ | 21.1‡ | 23.5 | 14.8 (4.9, 24.7) | 12.4 (−8, 32.8) | −2.4 (−24.7, 19.9) |
| SSA/Ro 60 | 47.3‡ | 22.5‡ | 29.4 | 24.7 (14.6, 34.9) | 17.9 (−4, 39.7) | −6.9 (−30.6, 16.9) |
| SSB/La | 15.9‡ | 5.6‡ | 11.8 | 10.3 (4.5, 16.1) | 4.2 (−11.3, 19.6) | −6.1 (−22.4, 10.1) |
| Sm | 24.7‡ | 5.7‡ | 11.8 | 19 (12.9, 25) | 12.9 (−2.6, 28.5) | −6.1 (−22.3, 10.2) |
| U1 RNP | 32.4‡ | 11.3‡ | 11.8 | 21.1 (13.3, 29) | 20.6 (−1.7, 43) | −0.5 (−17.5, 16.5) |
| Lupus anticoagulant | 20.8 | 20.6 | 6.7 | 0.1 (−10.2, 10.5) | 14.1 (−6.5, 34.7) | 14 (−2.1, 30.1) |
| Anticardiolipin | 12.6 | 11.1 | 12.5 | 1.5 (−6.6, 9.5) | 0.1 (−16.3, 16.4) | −1.4 (−19.4, 16.6) |
| Anti–β2- | 15 | 15.9 | 12.5 | 0.8 (−10.1, 8.5) | 2.5 (−13.8, 18.9) | 3.4 (−15.2, 21.9) |
Values are the difference (95% confidence interval) unless indicated otherwise. ACR = American College of Rheumatology; SLEDAI-2K = Systemic Lupus Erythematosus Disease Activity Index 2000; dsDNA = double-stranded DNA; PCNA = proliferating cell nuclear antigen; TRIM21 = tripartite motif 21; SSA = Sjögren’s syndrome antigen A; SSB = Sjögren’s syndrome antigen B; RNP = ribonucleoprotein.
Some predictors had a small number of missing values. When these occurred, the observations were excluded from the relevant analysis. In particular, for the small group of patients with an isolated CMP, the data included 1 missing value for education, smoking status, nephritis, proteinuria, no. of ACR criteria, anticardiolipin, and anti–β2-glycoprotein 1, and 2 missing values for high alcohol use and lupus anticoagulant.
Values with the same footnote symbol are significantly different from each other.
Values with the same footnote symbol are significantly different from each other.
Values are significantly different from ‡ and §, but ‡ and § are not different from each other.