Characteristics of the 19 patients with primary Sjögren’s syndrome with anti-RNP and anti-SSA antibodies at inclusion, as compared with others patients with primary Sjögren’s syndrome from the Paris-Sud cohort with anti-SSA antibodies
| Characteristics | Primary Sjögren with anti-RNP and anti-SSA, n=19 | Primary Sjögren without anti-RNP (Paris-Sud cohort), n=297 | P value |
| Number of women/men (ratio) | 16/3 (5.3) | 284/13 (21.8) | 0.0627 |
| Classification | |||
| Subjective xerostomia or xerophthalmia | 19 (100.0) | 293/297 (98.7) | 1 |
| Objective xerostomia or xerophthalmia | 13/14(92.9) | 260/286(90.9) | 1 |
| Lymphocytic sialadenitis (focus score ≥1) | 12 (63.2) | 222/279 (79.6) | 0.1429 |
| Median Chisholm score | 3.5 (2.0–4.0) | 3.0 (3.0–4.0) | 0.6078 |
| Positive anti-SSA antibodies | 19 (100.0) | 298/298 (100.0) | – |
| Positive anti-SSB antibodies | 5(26.3) | 161/295(54.6) | 0.0186 |
| Positive anti-Sm antibodies | 5 (26.3) | 0 (0.0) | – |
| Positive anti-RNP antibodies | 19 (100.0) | 0 (0.0) | – |
| Positive MCTD criteria at inclusion | 2 (10.5) | 0 (0.0) | – |
| Sharp et al | 0 (0.0) | 0 (0.0) | – |
| Kasukawa and Sharp | 2 (10.5) | 0 (0.0) | – |
| Alarcon-Segovia and Villareal | 2 (10.5) | 0 (0.0) | – |
| Age at onset of Sjögren’s symptoms | 41.0 (27.5–47.5) | 49.0 (36.5–61.0) | 0.0173 |
| ESSDAI at inclusion | 8.0 (5.5–16.5) | 3.0 (1.0–7.0)/89 | <0.0001 |
| Systemic manifestations | |||
| Constitutional symptoms | 3(15.8) | 1/278(0.004) | 0.0009 |
| Parotid gland involvement | 6 (31.6) | 136/293 (46.4) | 0.2082 |
| Joint involvement | 17 (89.5) | 211/293 (72.0) | 0.1142 |
| Myalgia | 4 (21.1) | 91/290 (31.4) | 0.4464 |
| Myositis | 3(15.8) | 8/288(2.8) | 0.0243 |
| Myalgia, 1N<CK<6N | 1 (5.3) | NA | – |
| Myalgia, CK≥6N | 2 (10.5) | NA | – |
| Myositis on the MRI | 1 (5.3) | NA | – |
| Histological confirmation | 2 (10.5) | NA | – |
| Pulmonary interstitial lung disease | 3 (15.8) | 20/290 (6.9) | 0.1589 |
| Cutaneous involvement | 4 (21.1) | 28/288 (9.7) | 0.1224 |
| Raynaud phenomenon | 9 (47.4) | 98/291 (33.7) | 0.2239 |
| Peripheral nervous system involvement | 2 (10.5) | 8/283 (2.8) | 0.1248 |
| Lymphoma | 1 (5.3) | 13/294 (4.4) | 0.5918 |
| Treatment | |||
| Corticosteroids | 9(47.4) | 45/288(15.6) | 0.0019 |
| NSAIDs | 4 (21.1) | 59/286 (20.6) | 1 |
| Hydroxychloroquine | 11(57.9) | 62/288(21.5) | 0.0010 |
| Methotrexate | 2 (10.5) | 9/288 (3.1) | 0.1429 |
| Biology | |||
| Positive ANA antibodies | 19 (100.0) | 250/292 (85.6) | 0.0877 |
| Positive RF | 10 (52.6) | 177/290 (61.0) | 0.4679 |
| Lymphopenia * | 4 (21.1) | 38/287 (13.2) | 0.3098 |
| Gammaglobulins or IgG >16 g/L | 15(78.9) | 152/291(52.2) | 0.0310 |
| Cryoglobulinemia | 1 (4.8) | 4/281 (1.4) | 0.2807 |
| Low C4† | 6 (31.6) | 69/269 (2.6) | 0.5916 |
| Increased CK* | 3/13 (23.1) | 2/15 (13.3) | 0.6389 |
| Median ANA value | 1/1280 | 1/1280 | 0.5304 |
| Median gammaglobulins, g/L | 24.0 (16.5–30.95) | 14.0(12.75–16.25)/40 | 0.0013 |
| Median IgG, g/L | 21.4 (16.5–32.6) | 14.8 (11.7–18.9)/172 | 0.0057 |
| Median beta-2 microglobulin, mg/L | 2.9 (2.2–4.4) | 2.4 (1.9–3.0)/259 | 0.1377 |
| Median C4 value, g/L | 0.18 (0.14–0.22) | 0.20 (0.15–0.25)/269 | 0.2230 |
| Median CK value, U/L | 103.0 (77.5–272.5) | 72.0 (50.0–84.8)/16 | 0.0992 |
Results are presented as number (%), or median (IQR).
Bold values are statistically significant.
*Normal CK value <170 U/L, lymphocytes count <1.0 G/L.
†C4 value≤0.15 g/L.
ANA, antinuclear antibodies; CK, creatine kinase; EMG, electromyogram;ESSDAI, EULAR Sjögren’s syndrome disease activity index; MCTD, mixed connective tissue disease; NA, not available;NSAIDs, non-steroidal anti-inflammatory drugs;RF, rheumatoid factor.