Clinical and serological correlates of anti-Sm autoantibodies in Chinese patients with systemic lupus erythematosus: 1,584 cases

Serological and clinical associations of autoantibodies in Chinese patients with new-onset systemic lupus erythematosus

To study the clinical significance of autoantibodies in Chinese patients with new-onset systemic lupus erythematosus (SLE), we enrolled 526 new-onset patients who met the 1997 Updated American College of Rheumatology SLE Classification Criteria for a retrospective cohort study. Chi-square test and Wilcoxon rank-sum test were used to detect the relationship of autoantibodies with clinical manifestations and serological results respectively. Our results demonstrated that the positive rate of anti-ribosomal P protein (anti-P) antibody in female patients was higher than that in male patients (41.2% vs. 22%, P = 0.008). Patients with anti-SSB (43.95 ± 73.12 vs. 40.92 ± 75.75, P = 0.004; 63.93 ± 103.56 vs. 55.06 ± 120.84, P = 0.008 respectively) antibodies had higher levels of alanine aminotransferase (ALT) and aspartate transaminase (AST), whereas those with anti-P antibody (28.90 ± 25.70 vs. 50.08 ± 93.00, P = 0.014; 38.51 ± 48.19 vs. 69.95 ± 142.67, P = 0.047, respectively) had lower levels of them. Anti-dsDNA antibody (P = 0.021) was associated with pulmonary arterial hypertension (PAH). The patients with anti-Ro60 (P = 0.044), anti-P (P = 0.012) and anti-dsDNA (P = 0.013) antibodies were less likely to develop Interstitial lung disease. Anti-SmRNP antibody was correlated to lower prevalence of neuropsychiatric symptoms (P = 0.037), and patients with anti-centromere antibody (ACA) were more likely to develop serositis (P = 0.016).We identified five clusters of SLE-related autoantibodies, confirmed previously reported associations of autoantibodies, and discovered new associations.

Relationship between hyperuricemia and serositis in patients with lupus nephritis

PURPOSE

To investigate the clinical and pathological characteristics of lupus nephritis (LN) patients with serositis and analyse the relationship between serositis and hyperuricemia (HUA) in LN patients in northeast China.

METHODS

The data of patients with LN diagnosed by renal biopsy in our hospital from April 2013 to May 2020 were retrospectively analyzed. The differences between the non-serositis and serositis groups were compared by t tests and Chi-square test. Factors with P < 0.05 in the univariate analyses were investigated further using binary logistic regression analysis to investigate the independent risk factors of serositis in patients with LN.

RESULTS

LN patients with serositis were more likely to have fever, hypertension, neuropsychiatric and hematological involvement than those without serositis (P < 0.05). Compared with the non-serositis group, LN patients with serositis were prone to have HUA, high D-dimer, high triglycerides, and had significant differences in the levels of plasma albumin (Alb), estimated glomerular filtration rate (eGFR), erythrocyte sedimentation rate, C-reactive protein, complement C3, 24-h urinary protein, pathological types, pathological score and SLEDAI score. Logistic regression analysis showed that HUA was one of risk factors for serositis in LN patients. The rate of complete remission in LN patients with serositis was significantly lower (P < 0.05) and the rate of no remission and mortality were significantly higher (P < 0.05) than LN patients without serositis.

CONCLUSION

LN patients with serositis had more severe clinical and pathological manifestations, higher systemic lupus erythematosus (SLE) activity and worse prognosis. Hyperuricemia is associated with serositis in LN patients.

Clinical features of new-onset systemic lupus erythematosus during pregnancy in Central China: a retrospective study of 68 pregnancies

The aim of this study is to explore the clinical features and pregnancy outcomes of Chinese patients with new-onset systemic lupus erythematosus (SLE) during pregnancy or puerperium. We retrospectively evaluated the data of all pregnant women with SLE managed at the First Affiliated Hospital of Zhengzhou University between April 2013 and March 2017. Clinical characteristics, laboratory features, medication use, and pregnancy outcomes were compared between pregnant women with new-onset SLE and pregnant women with pre-existing SLE. Risk factors for adverse pregnancy outcomes were determined using binary regression analyses. Overall, 223 pregnancies in 216 patients were included; 148 (69.6%) patients had a history of SLE, and 68 (30.4%) were diagnosed with SLE during pregnancy or puerperium. Most cases of new-onset SLE (72.1%) occurred during the first and second trimesters. Thrombocytopaenia (especially severe thrombocytopaenia) (76.5% vs 54.2%, P = 0.008; 39.7% vs 15.5%, P = 0.001) and anaemia (especially moderate anaemia) (73.5% vs 56.9%, P = 0.007; 52.9% vs 35.2%, P = 0.035) were more common in women with new-onset SLE than in women with pre-existing SLE and active disease during pregnancy. Additionally, patients with new-onset SLE experienced higher rates of moderate-to-severe disease activity than patients with pre-existing SLE (P < 0.01); disease activity occurred mostly during the first and second trimesters (75.4%). Compared with pre-existing SLE patients, disease activity in new-onset SLE patients occurred mostly in the first trimester (33.3% vs 15.3%, P = 0.043) and less in the third trimester (21.1% vs 47.2%, P < 0.001). Pregnancy loss was significantly higher in patients with new-onset SLE than in patients with pre-existing SLE (62.4% vs 27.1%, P < 0.001), with most cases occurring during the first and second trimesters (95.3%). However, there were no significant differences in neonatal outcomes between new-onset and pre-existing SLE patients with active disease. Within the new-onset SLE group, active disease was an independent risk factor for pregnancy loss (odds ratio [OR] = 16.185, confidence interval [CI] = 1.895-138.232, P = 0.011), whereas disease onset at late gestation was a protective factor against pregnancy loss (OR = 0.589, CI = 0.435-0.796, P = 0.013). Patients with new-onset SLE suffered greater haematological involvement (mainly thrombocytopaenia and anaemia) and higher rates of moderate-to-severe disease activity and pregnancy loss than patients with pre-existing SLE. Controlling disease activity and extending gestational age may improve pregnancy outcomes in women with new-onset SLE. Key Points • The clinical features of new-onset SLE during pregnancy and its impact on pregnancy outcomes have rarely been reported, especially in Chinese patients. • New-onset SLE during pregnancy in Chinese women occurred primarily during the first and second trimesters and was characterised by haematological disorders, including thrombocytopaenia and anaemia. • Women with new-onset SLE during pregnancy had significantly higher disease activity scores and pregnancy loss rates than women with pre-existing SLE, especially during the first and second trimesters; controlling disease activity and prolonging gestational age may improve pregnancy outcomes in this setting.

Natural products action on pathogenic cues in autoimmunity: Efficacy in systemic lupus erythematosus and rheumatoid arthritis as compared to classical treatments

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), which are characterized by self-perpetuating inflammation and tissue/organ damage, resulting from the failure of lymphocyte auto-tolerance, cause morbidity and mortality worldwide. The current drugs or therapies including conventional non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs), as well as several biologic therapies such as B cell-targeted, T cell-targeted, cytokines-targeted and cytokines receptors-targeted therapy, cannot completely cure SLE and RA, and are always accompanied by unexpected side effects. Therefore, more studies have explored new methods for therapy and found that the herbal medicine as well as its natural products (NPs) exhibited promising therapeutic value through exerting effects of immunomodulation, anti-inflammation, anti-oxidation, and anti-apoptosis, etc. via regulating abnormal responses in kidney, innate and adaptive immune systems, intestine, synoviocytes, as well as bone system including chondrocytes, osteoclasts, joints and paw tissues. In the present review, we will elucidate the current mainstream drugs and therapies for SLE and RA, and summarize the efficacy and mechanisms of NPs in the treatment of SLE and RA based on available findings including in vitro and in vivo animal models, as well as clinical studies, and further analyze the existing challenges, in order to provide comprehensive evidence for improvement of SLE and RA therapy by NPs and to promote management of these two autoimmune diseases.

Salvianolic acid A alleviates renal injury in systemic lupus erythematosus induced by pristane in BALB/c mice

The purpose of this study was to investigate the effects of salvianolic acid A (SAA) in systemic lupus erythematosus (SLE) induced by pristane in BALB/c mice. Lupus mice were established by confirming elevated levels of autoantibodies and IL-6 after intraperitoneal injection of pristane. Mice were then treated with daily oral doses of SAA for 5 months in parallel with mice treated with prednisone and aspirin as positive controls. The levels of autoantibodies were monitored at monthly intervals and nephritic symptoms observed by hematoxylin and eosin (H&E) and periodic acid–Schiff (PAS) staining. Western blot analysis of renal tissue was also employed. SAA treatment caused a significant reduction in the levels of anti-Sm autoantibodies and reduced renal histopathological changes and pathological effects. SAA treatment also significantly inhibited the phosphorylation of IKK, IκB and NFκB in renal tissues of lupus mice. In conclusion, the results suggest that SAA alleviates renal injury in pristane-induced SLE in BALB/c mice through inhibition of phosphorylation of IKK, IκB and NFκB.

Clinical associations of anti-Smith antibodies in PROFILE: a multi-ethnic lupus cohort

The aim of this study was to determine the association of anti-Sm antibodies with clinical manifestations, comorbidities, and disease damage in a large multi-ethnic SLE cohort. SLE patients (per American College of Rheumatology criteria), age ≥16 years, disease duration ≤10 years at enrollment, and defined ethnicity (African American, Hispanic or Caucasian), from a longitudinal US cohort were studied. Socioeconomic-demographic features, cumulative clinical manifestations, comorbidities, and disease damage (as per the Systemic Lupus International Collaborating Clinics Damage Index [SDI]) were determined. The association of anti-Sm antibodies with clinical features was examined using multivariable logistic regression analyses adjusting for age, gender, ethnicity, disease duration, level of education, health insurance, and smoking. A total of 2322 SLE patients were studied. The mean (standard deviation, SD) age at diagnosis was 34.4 (12.8) years and the mean (SD) disease duration was 9.0 (7.9) years; 2127 (91.6%) were women. Anti-Sm antibodies were present in 579 (24.9%) patients. In the multivariable analysis, anti-Sm antibodies were significantly associated with serositis, renal involvement, psychosis, vasculitis, Raynaud's phenomenon, hemolytic anemia, leukopenia, lymphopenia, and arterial hypertension. No significant association was found for damage accrual. In this cohort of SLE patients, anti-Sm antibodies were associated with several clinical features including serious manifestations such as renal, neurologic, and hematologic disorders as well as vasculitis.

Role of autoantibody testing

Autoantibodies are the serological hallmark of autoimmune disease. Though their pathogenic role is debatable, they play an important role in the management of a patient with rheumatic disease. However, due to their presence in the general population as well as in multiple autoimmune diseases, the presence of an autoantibody alone does not make a diagnosis; the result has to be interpreted along with clinical findings. Similarly, the absence of autoantibody does not exclude a disease. The common autoantibodies used in clinical practice include rheumatoid factor, anti-CCP antibodies, antinuclear antibodies (ANAs), anti-neutrophil cytoplasmic antibodies (ANCA) and anti-phospholipid antibodies. Once an autoantibody to a broad antigen is detected in a patient, sub-specificity analysis can improve the utility of the antibody. Autoantibodies are detected in the serum using different assays and results of which can vary; thus, it is important for a clinician to know the method used, its sensitivity and specificity to help in the proper interpretation of the laboratory results. This review will address these issues.

Systemic lupus erythematosus patients in the low-latitude plateau of China: altitudinal influences

The current study was to investigate the features of hospitalized patients with systemic lupus erythematosus (SLE) at different altitudes. The correlation between SLE activity and altitudinal variations was also explored. Medical records of 1029 patients were retrospectively reviewed. Activity of SLE in each organ system was recorded using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). There was no significant correlation between SLE activity and altitudes (r = 0.003, p = 0.159). Age at onset for SLE patients at high altitudes was significantly younger than that at low and moderate altitudes (p = 0.022 and p = 0.004, respectively). Age at SLE admission at low altitudes was significant older than those at moderate and high altitudes (p = 0.011 and p < 0.001, respectively). Patients at high altitudes had shorter duration from disease onset to admission than those at moderate altitudes (p = 0.009). Incidence of Sm antibodies-positive for resident patients at high altitudes was 36.4%, which were higher than that at moderate altitudes (p = 0.003). We found increasing trends of CNS activity in active patients; immunological and renal activities in inactive patients were correlated with elevated altitudes (p = 0.024, p = 0.004, p = 0.005), while arthritis scores in active patients showed the tendency of decreasing with the rise of elevation (p = 0.002). Hemoglobin level, red blood cell and platelet counts at high altitudes were significantly lower than those at low altitudes (p < 0.05, respectively). There was no significant difference in hemoglobin level between moderate- and low-altitude groups (p > 0.05). No significant difference in platelet counts between moderate- and high-altitude groups was observed (p > 0.05). Our findings suggest that some clinical features, laboratory tests and activity of main organs in SLE are influenced by altitudes. Furthermore, organ activities of active and inactive SLE patients have different patterns of altitudinal variations. These distinctive variations likely reveal that peculiar environmental factors at high altitudes can affect the development of SLE.

Chinese SLE treatment and research group registry: III. association of autoantibodies with clinical manifestations in Chinese patients with systemic lupus erythematosus

We investigated the characteristics of Chinese SLE patients by analyzing the association between specific autoantibodies and clinical manifestations of 2104 SLE patients from registry data of CSTAR cohort. Significant (P < 0.05) associations were found between anti-Sm antibody, anti-rRNP antibody, and malar rash; between anti-RNP antibody, anti-SSA antibody, and pulmonary arterial hypertension (PAH); between anti-SSB antibody and hematologic involvement; and between anti-dsDNA antibody and nephropathy. APL antibody was associated with hematologic involvement, interstitial lung disease, and a lower prevalence of oral ulcerations (P < 0.05). Associations were also found between anti-dsDNA antibody and a lower prevalence of photosensitivity, and between anti-SSA antibody and a lower prevalence of nephropathy (P < 0.05). Most of these findings were consistent with other studies in the literature but this study is the first report on the association between anti-SSA and a lower prevalence of nephropathy. The correlations of specific autoantibodies and clinical manifestations could provide clues for physicians to predict organ damages in SLE patients. We suggest that a thorough screening of autoantibodies should be carried out when the diagnosis of SLE is established, and repeated echocardiography annually in SLE patients with anti-RNP or anti-SSA antibody should be performed.

Serum nitrated nucleosome levels in patients with systemic lupus erythematosus: a retrospective longitudinal cohort study

Introduction

Circulating nucleosomes released from apoptotic cells are important in the pathogenesis of systemic lupus erythematosus (SLE). Both nucleosomes and anti-nucleosome antibodies are deposited in inflamed tissues in patients with SLE. Active inflammation promotes nitration of tyrosine residues on serum proteins. Our hypothesis was that levels of nitrated nucleosomes would be elevated in patients with SLE and could be associated with disease activity. We therefore carried out a retrospective longitudinal study to investigate factors affecting levels of nitrated nucleosomes (NN) in patients with SLE.

Methods

A novel serum ELISA was developed to measure serum NN and modified to measure serum nitrated albumin (NA). Levels of both NN and NA were measured in 397 samples from 49 patients with SLE followed through periods of disease flare and remission for a mean of 89 months. Anti-nucleosome antibody (anti-nuc) levels were measured in the same samples. The effects of 24 different clinical, demographic and serological variables on NN, NA and anti-nuc levels were assessed by univariable and multivariable analysis.

Results

Patients with SLE had higher mean NN than healthy controls or patients with other autoimmune rheumatic diseases (P =0.01). Serum samples from 18 out of 49 (36.7%) of SLE patients were never positive for NN. This group of 18 patients was characterized by lower anti-double stranded DNA antibodies (anti-dsDNA), disease activity and use of immunosuppressants. In the remaining 63.3%, NN levels were variable. High NN was significantly associated with anti-Sm antibodies, vasculitis, immunosuppressants, hydroxychloroquine and age at diagnosis. NN levels were raised in neuropsychiatric flares. NN levels did not completely parallel NA results, thus providing additional information over measuring nitration status alone. NN levels were not associated with anti-nuc levels.

Conclusions

NN are raised in a subset of patients with SLE, particularly those who are anti-Sm positive. Elevated NN may be a marker of vascular activation and neuropsychiatric flares in these patients.

The frequency of and associations with hospitalization secondary to lupus flares from the 1000 Faces of Lupus Canadian cohort

Objectives

Hospitalization is a major factor in health care costs and a surrogate for worse outcomes in chronic disease. The aim of this study was to determine the frequency of hospitalization secondary to lupus flare, the causes of hospitalization, and to determine risk factors for hospitalization in patients with systemic lupus erythematosus (SLE).

Methods

Data were collected as part of the 1000 Canadian Faces of Lupus, a prospective cohort study, where annual major lupus flares including hospitalizations were recorded over a 3-year period.

Results

Of 665 patients with available hospitalization histories, 68 reported hospitalization related to a SLE flare over 3 years of follow-up. The average annual hospitalization rate was 7.6% (range 6.6–8.9%). The most common reasons for hospitalization were: hematologic (22.1%), serositis (20.6%), musculoskeletal (MSK) (16.2%), and renal (14.7%). Univariate risk factors for lupus hospitalization included (OR [95% CI]; p < 0.05): juvenile-onset lupus (2.2 [1.1–4.7]), number of ACR SLE criteria (1.4 [1.1–1.7], baseline body mass index (BMI) (1.1 [1.0–1.1]), psychosis (3.4 [1.2–9.9]), aboriginal race (3.2 [1.5–6.7]), anti-Smith (2.6 [1.2–5.4]), erythrocyte sedimentation rate >25 mm/hr (1.9 [1.1–3.4]), proteinuria >0.5 g/d (4.2 [1.9–9.3], and SLAM-2 score (1.1 [1.0–1.2]). After multivariate regression only BMI, number of ACR criteria, and psychosis were associated with hospitalization for lupus flare.

Conclusions

The mean annual rate of hospitalization attributed to lupus was lower than expected. Hematologic, serositis, MSK and renal were the most common reasons. In a regression model elevated BMI, more ACR criteria and psychosis were associated with hospitalization.

Meta-analysis followed by replication identifies loci in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with systemic lupus erythematosus in Asians

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic involvement and ethnic differences. Susceptibility genes identified so far only explain a small portion of the genetic heritability of SLE, suggesting that many more loci are yet to be uncovered for this disease. In this study, we performed a meta-analysis of genome-wide association studies on SLE in Chinese Han populations and followed up the findings by replication in four additional Asian cohorts with a total of 5,365 cases and 10,054 corresponding controls. We identified genetic variants in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with the disease. These findings point to potential roles of cell-cycle regulation, autophagy, and DNA demethylation in SLE pathogenesis. For the region involving TET3 and that involving CDKN1B, multiple independent SNPs were identified, highlighting a phenomenon that might partially explain the missing heritability of complex diseases.

Prognostic indicators of hospitalized patients with systemic lupus erythematosus: a large retrospective multicenter study in China

OBJECTIVE

To investigate the mortality of hospitalized patients with systemic lupus erythematosus (SLE) and determine the influential factors associated with poor prognosis.

METHODS

Medical records of 1956 SLE inpatients from 15 hospitals during the period January 1, 1999, to December 31, 2009, were reviewed. All patients were followed up in January 2010. Potential factors associated with mortality were analyzed, comparing patients who were living with those who were deceased. The independency of those factors significantly related to death was determined by Cox regression analysis.

RESULTS

Male to female ratio was 1:15 in this cohort; median age at disease onset was 30 years. Hematologic (70.0%), mucocutaneous (68.2%), musculoskeletal (57.9%), and renal (48.7%) involvements were most often seen in these patients at time of admission. The overall mortality was 8.5% (n = 166), with infection (25.9%), renal failure (19.3%), and neuropsychiatric lupus (18.7%) the leading 3 causes of death. Independent predictors for mortality in this cohort of SLE patients were neuropsychiatric involvement [hazard ratio (HR) 2.19], anemia (HR 1.69), SLEDAI score > 8 at discharge (HR 1.64), increased serum creatinine (HR 1.57), low serum albumin (HR 1.56), cardiopulmonary involvement (HR 1.55), and patient untreated before admission (HR 1.48), whereas the use of antimalarial drugs (HR 0.62) and positive anti-Sm antibody (HR 0.60) were shown to be protective factors.

CONCLUSION

SLE patients with delayed treatment and refractory disease have poorer prognosis. A high incidence of death would be expected if they have neuropsychiatric involvement, anemia, azotemia, or cardiopulmonary involvement. Combination therapy with antimalarial drugs may provide some benefit to patients with SLE.

Sm peptides in differentiation of autoimmune diseases

Systemic lupus erythematosus (SLE) and related diseases are characterized by circulating autoantibodies to defined intracellular targets. Among the earliest identified autoantibodies were those directed to components of U2-U6 small nuclear ribonucleoproteins (snRNPs) known as Smith (Sm) antigen, which are highly specific for SLE. The Sm-antigen is composed of at least nine different polypeptides with molecular weights ranging from 9 to 29.5 kDa (B (B1, 28 kDa), B' (B2, 29 kDa), N (B3, 29.5 kDa), D1 (16 kDa), D2 (16.5 kDa), D3 (18 kDa), E (12 kDa), F (11 kDa), and G (9 kDa)). All of the nine core proteins, but most frequently the B and D polypeptides, are targets of the anti-Sm autoimmune response. However, since SmBB' and U1 specific RNPs share the cross-reactive epitope motif PPPGMRPP, SmD is regarded as the most SLE specific Sm-antigen. It has been shown that the polypeptides D1, D3, and BB' contain symmetrical dimethylarginine, constituting a major autoepitope within the C-terminus of SmD1 and SmD3. Several synthetic peptides have been used for the detection of anti-Sm antibodies and thus for the diagnosis of SLE. Anti-Sm antibodies have been reported to occur later than other SLE associated autoantibodies and, on average, around 1 year before the clinical onset of SLE. The present review provides a comprehensive summary on the history of anti-Sm antibodies and their use as biochemical tools to study cellular processes and as biomarker in the diagnosis of SLE. Additionally, a meta-analysis focused on recent data analyzes the prevalence of anti-Sm antibodies in SLE.

Clinical and serologic correlations and autoantibody clusters in systemic lupus erythematosus: a retrospective review of 917 patients in South China

Ethnicity and environmental factors could be involved in the heterogeneity of systemic lupus erythematosus (SLE). We conducted this study to define clinical and serologic correlations and autoantibody clusters in SLE patients in South China. We retrospectively reviewed the records of 917 patients with SLE admitted to our hospital between January 2005 and June 2008. We found the following associations between autoantibodies and clinical manifestations to be statistically significant: anti-double-stranded DNA (anti-dsDNA) with higher prevalence of renal disorder, leukopenia, and anemia; anti-Sm with higher prevalence of malar rash/discoid rash, pericarditis, and leukopenia; anti-ribonucleoprotein (anti-RNP) with higher prevalence of Raynaud phenomenon and photosensitivity; anti-deoxyribonucleoprotein (anti-DNP) with higher prevalence of arthritis and lower prevalence of renal disorder; anti-Scl-70 with higher prevalence of anemia and Raynaud phenomenon; anti-Jo-1 with higher prevalence of pericarditis; and anti-centromere with higher prevalence of Raynaud phenomenon. Three autoantibody clusters were identified: Cluster 1 (anti-Ro, anti-Sm, and anti-RNP [Ro/Sm/RNP], with a significantly lower percentage of elderly SLE and higher prevalence of photosensitivity, malar rash/discoid rash, Raynaud phenomenon, and leukopenia); Cluster 2 (anti-Ro [Ro], with a lower percentage of pediatric SLE); and Cluster 3 (the absence of anti-extractable nuclear antigen antibodies [ENA ve], with a lower percentage of adult SLE and lower prevalence of alopecia). In summary, this study not only confirms both anti-dsDNA and anti-Sm as specific markers for classifying SLE, but also demonstrates that photosensitivity is not associated with anti-Ro but with anti-RNP, and a negative association is found between renal disorder and anti-DNP in patients in South China. These results are different from results found in other populations. The higher prevalence of anti-dsDNA and renal disorder results in less difference in the prevalence of anti-dsDNA and renal disorder among the 3 autoantibody clusters in SLE patients in South China, which could be related to ethnicity and widespread industrial pollution in South China.