Little information exists about the association of anti-SSA/Ro60 and anti-Ro52/TRIM21 with systemic lupus erytematosus (SLE) features. In this work, we analysed the associations of both anti-Ro reactivities with clinical and immunological manifestations in 141 SLE patients. Photosensitivity and xerophtalmia/xerostomia were found to be positively associated with both anti-SSA/Ro60 (
Anti-SSA/Ro60 and anti-Ro52/TRIM21 are among the most commonly detected autoantibodies in the routine screening for systemic autoimmune diseases. Although both antibody reactivities were considered to form part of the anti-Ro system for a long time, now it is clearly established that their antigens are different, do not form part of a stable macromolecular complex, and are located in different cellular compartments (reviewed in [
Among systemic autoimmune diseases, SLE displays a specific anti-Ro antibody pattern. Thus, although simultaneous reactivity is the more frequent antibody pattern, this disease shows the highest prevalence of isolated anti-SSA/Ro60 [
Sera from 141 SLE patients (131 females, mean age at diagnosis 36.7 ± 14.5 years) who fulfilled the American College of Rheumatology (ACR) criteria were selected for this study [
Sera corresponding to different patient’s revisions were collected and stored at −20°C. The last serum from each patient was selected for the study (period of collection from February 2007 to March 2011). The mean age at time of analysis was
Determination of anti-SSA/Ro60 and anti-Ro52/TRIM21 antibodies in the 141 selected SLE patients was performed by fluoro enzyme immunoassay (Thermo Fisher Scientific-Phadia GmbH, Freiburg, Germany). The assay was carried out on an automated ImmunoCAP 250 analyser. In all patients, other SLE ANA specificities (anti-dsDNA, SS-B/La, U1RNP, and Sm) and anticardiolipin (CL) IgG and IgM antibodies were also simultaneously determined with the same methodology. C3 and C4 levels were measured by nephelometry (Beckman Coulter Inc., California, USA).
Levels of haematologic parameters, quantified using an Advia 2120 analyzer (Siemens Healthcare, Erlangen, Germany), were available at the time of autoantibody determination in 128 patients (119 females; mean age at diagnosis and at analysis
The association of the presence of anti-SSA/Ro60 and anti-Ro52/TRIM21 with SLE manifestations was analyzed by binary logistic regression adjusted for sex and age at diagnosis and at time of analysis. Previously, the presence of both anti-Ro specificities and of anti-dsDNA, SSB/La, RNP, Sm, and CL antibodies was simultaneously analyzed by forward stepwise logistic regression procedure in order to show its influence on each clinical manifestation and immunological parameter. When appropriate, other autoantibodies found to be statistically influential were included in the binary logistic regression analysis of anti-SSA/Ro60 and anti-Ro52/TRIM21 associations. In this analysis, both anti-Ro reactivities were first included together as independent variables. In order to avoid multicollinearity effects caused by the close relationship existing between both specificities, an antibody separate analysis was performed when a not statistically significant association was found. Odds ratios (OR) and their 95% confidence interval (CI) were computed. Levels of complement and haematological parameters were compared by Student’s
The presence of anti-SSA/Ro60 and/or anti-Ro52/TRIM21 antibodies was detected in 62 out of the 141 SLE patients analyzed (44.0%). Simultaneous reactivity was the main observed antibody pattern, 37 patients being positive for both antibodies (26.2%). Anti-SSA/Ro60 alone was present in 23 (16.3%), whereas isolated anti-Ro52/TRIM21 reactivity was only found in two patients (1.4%). Thus, the antibody pattern in this patients’ series was in agreement with the established relationship between anti-SSA/Ro60 and SLE and it was not associated with either age at diagnosis or gender prevalence (Table
Demographic characteristics of SLE patients on the basis of their anti-SSA/Ro60 and anti-Ro52/TRIM21 pattern.
Antibody pattern | Age at SLE diagnosis | Gender | ||
---|---|---|---|---|
Anti-SSA/Ro60 | Anti-Ro52/TRIM21 | 141 patients |
Mean ± SD years | Female (%) |
+ | + | 37 (26.2) | 38.8 ± 12.5 | 94.6 |
+ | − | 23 (16.3) | 35.9 ± 13.8 | 91.3 |
− | + | 2 (1.4) | 32.5 ± 10.6 | 100 |
− | − | 79 (56.0) | 36.1 ± 15.8 | 92.4 |
When anti-SSA/Ro60 and anti-Ro52/TRIM21 were simultaneously included as independent variables in the regression analysis, the only significant association found was cytopenia with anti-Ro52/TRIM21 (Table
Association of anti-SSA/Ro60 and anti-Ro52/TRIM21 with clinical manifestations in SLE.
141 patients | Anti-SSA/Ro60 ( |
Anti-Ro52/TRIM21 ( |
||||||
---|---|---|---|---|---|---|---|---|
Clinical manifestations |
|
% |
|
% | OR (95% CI) |
|
% | OR (95% CI) |
Malar rash | 88 | 62.4 | 38 | 63.3 | 0.82 (0.33–2.08) | 26 | 66.7 | 1.68 (0.59–4.76) |
Discoid lesions | 29 | 20.6 | 13 | 21.7 | 1.13 (0.38–3.39) | 7 | 17.9 | 0.69 (0.20–2.41) |
Photosensitivitya | 89 | 63.1 | 45 | 75.0 | 1.66 (0.64–4.29) | 31 | 79.5 | 1.90 (0.62–5.87) |
Oral ulcers | 78 | 55.3 | 31 | 51.7 | 0.45 (0.17–1.16) | 24 | 61.5 | 2.54 (0.88–7.38) |
Nonscarring alopeciab | 75 | 53.2 | 32 | 53.3 | 0.58 (0.21–1.56) | 23 | 59.0 | 1.09 (0.35–3.73) |
Arthritisc | 118 | 83.7 | 49 | 81.7 | 1.50 (0.37–6.09) | 31 | 79.5 | 0.98 (0.22–4.33) |
Serositis | 28 | 19.8 | 12 | 20.0 | 1.11 (0.37–3.37) | 7 | 17.9 | 0.88 (0.25–3.12) |
Renal involvementd | 45 | 31.9 | 21 | 35.0 | 1.21 (0.45–3.29) | 13 | 33.3 | 1.33 (0.44–4.06) |
Neurologic disordere | 23 | 16.3 | 11 | 18.3 | 1.60 (0.47–5.42) | 7 | 17.9 | 0.95 (0.25–3.58) |
Xerophthalmia/xerostomia | 37 | 26.2 | 22 | 36.7 | 1.86 (0.65–5.33) | 16 | 41.0 | 1.69 (0.56–5.05) |
Raynaud’s phenomenonf | 67 | 47.5 | 33 | 55.0 | 1.04 (0.41–2.61) | 24 | 61.5 | 2.42 (0.86–6.84) |
Neurologic disorder | 23 | 16.3 | 11 | 18.3 | 1.31 (0.41–4.25) | 7 | 17.9 | 0.98 (0.27–3.58) |
Cytopenia | 88 | 62.4 | 39 | 66.7 | 0.67 (0.27–1.66) | 29 | 74.3 |
|
Leukopenia or lymphopenia | 77 | 54.6 | 36 | 60.0 | 1.08 (0.44–2.64) | 25 | 64.1 | 1.74 (0.63–4.78) |
Thrombocytopeniah | 18 | 12.8 | 4 | 6.7 | 4 | 10.2 | ||
Haemolytic anaemiah | 5 | 3.5 | 2 | 3.3 | 3 | 7.7 |
Anti-SSA/Ro60 and anti-Ro52/TRIM21 analyzed together as independent variables by binary logistic regression analysis adjusted for sex and age (at diagnosis and time of analysis). Other autoantibodies also included as independent variable after selection by forward step procedure: aanti-dsDNA (negative association), banti-SS-B (positive association), canti-SSB (negative association), danti-dsDNA (positive association), eanti-cardiolipin (positive association), fanti-RNP (positive association), g
Similarly to cytopenia, oral ulcers and Raynaud’s phenomenon were also found to be positively, although not significantly, associated with anti-Ro52/TRIM21 (Table
In contrast, photosensitivity and xerophthalmia/xerostomia showed a not statistically significant positive association with both anti-SSA/Ro60 and anti-Ro52/TRIM21 (Table
None of the remaining clinical manifestations showed a significant association with anti-SSA/Ro60 and/or anti-Ro52/TRIM21 whether both antibodies were simultaneously or separately analyzed.
Anti-SSA/Ro60 and anti-Ro52/TRIM21 also showed a different association with SLE- related immunological parameters. Indeed, when the two anti-Ro reactivities were considered together as independent variables, an opposite behavior was observed regarding the presence of anti-dsDNA antibodies and hypocomplementemia, anti-SSA/Ro60 being positively associated and anti-Ro52/TRIM21 negatively associated (Table
Association of anti-SSA/Ro60 and anti-Ro52/TRIM21 with immunological parameters in SLE.
Immunological parameters | 141 patients | Anti-SSA/Ro60 ( |
Anti-Ro52/TRIM21 ( |
|||||
---|---|---|---|---|---|---|---|---|
|
% |
|
% | OR (95% CI) |
|
% | OR (95% CI) | |
Anti-dsDNA | 102 | 72.3 | 45 | 75.0 | 1.93 (0.64–5.79) | 26 | 66.7 |
|
Anti-Sm | 15 | 10.6 | 7 | 11.6 | 1.05 (0.24–4.61) | 5 | 12.8 | 1.2 (0.25–5.86) |
Antiphospholipid | 34 | 24.1 | 8 | 13.3 | 0.33 (0.10–1.08) | 5 | 12.8 | 0.97 (0.24–3.94) |
Anticardiolipin IgG/IgM | 20 | 14.2 | 4 | 6.7 | 0.38 (0.09–1.65) | 2 | 5.1 | 0.57 (0.08–3.88) |
Anti- |
20 | 14.2 | 6 | 10.0 | 0.52 (0.13–2.08) | 4 | 10.2 | 1.07 (0.22–5.27) |
Lupus anticoagulante | 14 | 9.9 | 2 | 3.3 | 1 | 2.5 | ||
Low complementa | 106 | 75.2 | 48 | 80.0 |
|
28 | 71.8 | 0.24 (0.05–1.09) |
Low C3a | 89 | 63.1 | 41 | 68.3 | 2.44 (0.78–7.64) | 24 | 61.5 | 0.52 (0.15–1.79) |
Low C4a | 97 | 68.8 | 47 | 78.3 |
|
27 | 69.2 | 0.25 (0.06–1.08) |
Anti-SSA/Ro60 and anti-Ro52/TRIM21 analyzed together as independent variables by binary logistic regression analysis adjusted for sex and age (at diagnosis and time of analysis). Other autoantibodies also included as independent variable after selection by forward step procedure: aanti-dsDNA (positive association), b
On the other hand, antiphospholipid antibodies were found to be negatively associated with anti-SSA/Ro60 (Table
Anti-Sm was the only analysed immunological parameter found not be associated either with anti-SSA/Ro60 or anti-Ro52/TRIM21 (Table
In order to confirm the previously observed association between anti-Ro52/TRIM21 and cytopenia, we compared the levels of haematological parameters at time of analysis in 128 SLE patients on the basis of their anti-Ro52/TRIM21 status (Table
Haematological parameters according to the anti-Ro52/TRIM21 status.
Anti-Ro52/TRIM21 | |||
---|---|---|---|
Positive |
Negative |
||
Mean ± SD or median (range)* | Mean ± SD or median (range)* |
|
|
Leucocytes ×103/µL | 5.11 ± 1.37 | 5.94 ± 2.25 |
|
Lymphocytes ×103/µL | 1.27 ± 0.48 | 1.52 ± 0.61 |
|
Neutrophils ×103/µL | 2.94 (1.70–6.90) | 3.38 (1.00–10.46) | 0.247 |
Platelets ×103/µL | 241.24 ± 78.23 | 235.19 ± 67.53 | 0.179 |
Haemoglobin mg/dL | 12.42 ± 1.53 | 12.91 ± 1.38 | 0.089 |
*According to data distribution.
In contrast, when considering anti-SSA/Ro60, the levels of haematological parameters showed a different behaviour (Table
Haematological parameters according to the anti-SSA/Ro60 status.
Anti-SSA/Ro60 | |||
---|---|---|---|
Positive |
Negative |
||
Mean ± SD or median (range)* | Mean ± SD or median (range)* |
|
|
Leucocytes ×103/µL | 5.64 ± 2.08 | 5.78 ± 2.10 | 0.704 |
Lymphocytes ×103/µL | 1.35 ± 0.48 | 1.52 ± 0.64 | 0.098 |
Neutrophils ×103/µL | 3.26 (1.60–10.46) | 3.24 (1.00–10.13) | 0.821 |
Platelets ×103/µL | 251.29 ± 73.33 | 224.50 ± 66.59 | 0.052 |
Haemoglobin mg/dL | 12.46 ± 1.41 | 13.00 ± 1.41 |
|
*According to data distribution.
In this work, anti-SSA/Ro60 and anti-Ro52/TRIM21 have been shown to display a different pattern of clinical and immunological associations in SLE. According to the previously described relationship between anti-SSA/Ro60 and SLE [
Both anti-Ro reactivities also displayed different behaviour regarding haematologic abnormalities. Thus, anti-Ro52/TRIM21 was found to be significantly associated with lymphopenia, independently of the therapeutic regime, whereas patients with anti-SSA/Ro60 antibodies showed higher platelet numbers and lower haemoglobin levels than negative patients. Lymphopenia has before been related to the presence of anti-Ro antibodies in SLE and SS [
Anti-Ro antibodies have previously been found to be associated with a lower prevalence of thrombocytopenia in SLE patients [
Similar to that observed in relation to lymphopenia, anti-Ro52/TRIM21 but not anti-SSA/Ro60 was found to be positively associated with Raynaud’s phenomenon. This relationship was independent of the presence of anti-U1RNP, an antibody known to be related to Raynaud’s phenomenon even in SLE [
Photosensitivity and xerophthalmia/xerostomia were the only features found to be positively associated with both anti-SSA/Ro60 and anti-Ro52/TRIM21. These associations were only statistically significant when both autoantibodies were separately analyzed probably due to the close relationship existing between them. Although antibodies against the Ro system have been historically considered to be associated with photosensitivity, this relationship remains controversial [
On the other hand, the association between xerophthalmia/xerostomia and anti-Ro is clearly established in SLE patients [
Anti-SSA/Ro60 and anti-Ro52/TRIM21 showed a different pattern of clinical and immunological associations in SLE. Beside common positive associations with photosensitivity and xerophthalmia/xerostomia, the two anti-Ro reactivities showed both positive and negative specific associations. Anti-SSA/Ro60 was found to be positively associated with hypocomplementemia but negatively with antiphospholipid antibodies, whereas anti-Ro52/TRIM21 showed a positive association with lymphopenia and Raynaud’s phenomenon and a negative relationship with anti-dsDNA antibodies. Thus, our data increases evidence on the different associations of both anti-Ro specificities with specific clinical manifestations even in a single disease.
The authors report no conflict of interests.
The study received no financial support from any organization. The authors thank Thermo Fisher Scientific-Phadia GmbH for generously providing autoantibody kits for the present study, Ana Ynés Martínez Paredes for her technical assistance, and Pablo Martínez Camblor from the Biomedical Investigation Office (OIB-FICYT) of the Principality of Asturias for the statistical analysis. They are also especially grateful to Dr. Carmen Gutiérrez and to the Asociación Lúpicos de Asturias for their encouragement and support. Iván Cabezas-Rodríguez is supported by the Río Hortega Programme, Instituto de Salud Carlos III, Spain.