Systemic Lupus Erythematosus-related Lung Disease

Systemic Lupus Erythematosus (SLE) is a multifaceted, multisystem autoimmune disorder with diverse clinical expressions. While prevalence reports vary widely, pulmonary involvement accounts for significant morbidity and mortality in SLE. This comprehensive review explores the spectrum of pulmonary disease in SLE, including upper airway manifestations (e.g., laryngeal affection), lower airway conditions (e.g., bronchitis, bronchiolitis, bronchiectasis), parenchymal diseases (e.g., interstitial lung disease, acute lupus pneumonitis, diffuse alveolar hemorrhage), pleural diseases (e.g., serositis, shrinking lung syndrome), and vascular diseases (e.g., pulmonary arterial hypertension, pulmonary embolism, acute reversible hypoxemia syndrome). We discuss diagnostic modalities, treatment strategies, and prognosis for each pulmonary manifestation. With diagnostics remaining a challenge and with the absence of standardized treatment guidelines, we emphasize the need for evidence-based guidelines to optimize patient care and improve outcomes in this complex disease.

Association of serum uric acid with right cardiac chamber remodeling assessed by cardiovascular magnetic resonance feature tracking in patients with connective tissue disease

Background

Right cardiac chamber remodeling is widespread in patients with connective tissue disease (CTD). Serum uric acid (SUA) is considered a potential independent risk factor for cardiovascular disease, and elevated SUA levels are often observed in patients with CTD. The correlation between SUA levels and right cardiac chamber remodeling remains unclear. This study investigated the association of SUA with right cardiac chamber remodeling as assessed by cardiac magnetic resonance feature-tracking (CMR-FT) in CTD patients.

Methods and results

In this cross-sectional study, a total of 104 CTD patients and 52 age- and sex-matched controls were consecutively recruited. All individuals underwent CMR imaging, and their SUA levels were recorded. The patients were divided into three subgroups based on the tertiles of SUA level in the present study. CMR-FT was used to evaluate the right atrial (RA) longitudinal strain and strain rate parameters as well as right ventricular (RV) global systolic peak strain and strain rate in longitudinal and circumferential directions for each subject. Univariable and multivariable linear regression analyses were used to explore the association of SUA with RV and RA strain parameters. Compared with the controls, the CTD patients showed significantly higher SUA levels but a lower RV global circumferential strain (GCS) and RA phasic strain parameters (all p < 0.05), except the RA booster strain rate. RV GCS remained impaired even in CTD patients with preserved RV ejection fraction. Among subgroups, the patients in the third tertile had significantly impaired RV longitudinal strain (GLS), RV GCS, and RA reservoir and conduit strain compared with those in the first tertile (all p < 0.05). The SUA levels were negatively correlated with RV GLS and RV GCS as well as with RA reservoir and conduit strain and strain rates (the absolute values of β were 0.250 to 0.293, all P < 0.05). In the multivariable linear regression analysis, the SUA level was still an independent determinant of RA conduit strain (β = -0.212, P = 0.035) and RV GCS (β = 0.207, P = 0.019).

Conclusion

SUA may be a potential risk factor of right cardiac chamber remodeling and is independently associated with impaired RA conduit strain and RV GCS in CTD patients.

Risk Factors for Pulmonary Arterial Hypertension in Patients With Systemic Lupus Erythematosus: A Systematic Review and Expert Consensus

OBJECTIVE

This study aimed to identify risk factors associated with the development of pulmonary arterial hypertension (PAH) in patients with systemic lupus erythematosus (SLE).

METHODS

We conducted a systematic literature review of studies focusing on adult patients classified as having SLE-related PAH by searching the electronic databases Embase, Medline, Medline in-progress, Wanfang, China National Knowledge Infrastructure, Ichushi Web, Kmbase, and KoreaMed. Based on the findings, we conducted a Delphi survey to build expert consensus on issues related to screening for PAH in patients with SLE and on the importance and feasibility of measuring the identified factors in clinical practice.

RESULTS

We included 21 eligible studies for data synthesis. Sixteen factors were associated with an increased risk of SLE-PAH: pericardial effusion, serositis, longer duration of SLE, arthritis, acute and subacute cutaneous lupus, scleroderma pattern on nailfold capillaroscopy, diffusion capacity of carbon monoxide in the lungs (DLCO) <70% predicted, interstitial lung disease, thrombocytopenia, and seven serological factors. Six factors were associated with a decreased risk of SLE-PAH: malar/acute rash, hematologic disorder, renal disorder, higher Systemic Lupus Erythematosus Disease Activity Index score, and two serological factors. Among these, there were six risk factors on which the panelists reached strong or general consensus (peak tricuspid regurgitation velocity on echocardiography >2.8 m/s, pericardial effusion, DLCO <70% predicted, scleroderma pattern on nailfold capillaroscopy, brain natriuretic peptide >50 ng/l, and N-terminal pro-brain natriuretic peptide >300 ng/l). The Delphi panel confirmed the need for a screening tool to identify patients with SLE at high risk of developing PAH and provided consensus on the importance and/or practicality of measuring the identified factors.

CONCLUSION

The risk factors we identified could be used in a screening algorithm to identify patients with SLE with a high risk of developing PAH to facilitate early diagnosis, which could improve prognosis and management of these patients.

Systemic Lupus Erythematosus and Pulmonary Hypertension

Pulmonary Hypertension (PH) is a common manifestation in patients with Systemic Lupus Erythematosus (SLE) and varies from asymptomatic to life-threatening disease. PH can result not only from immune system dysregulation, but also from various conditions, including cardiorespiratory disorders and thromboembolic diseases. Most commonly, SLE-related PH presents with non-specific symptoms, such as progressive dyspnea on exertion, generalized fatigue and weakness and eventually dyspnea at rest. Prompt diagnosis of SLE-related PH and early identification of the underlying pathogenetic mechanisms is demanded in order to introduce targeted therapy to prevent irreversible pulmonary vascular damage. In most cases the management of PH in SLE patients is similar to idiopathic pulmonary arterial hypertension (PAH). Furthermore, specific diagnostic tools like biomarkers or screening protocols, to establish early diagnosis seem to be not available yet. Although, the survival rates for patients with SLE-related PH vary between studies, it is evident that PH presence negatively affects the survival of SLE patients.

Relationship between serum uric acid and hypertension in patients with primary Sjögren's syndrome: A retrospective cohort study

Primary Sjögren's syndrome (pSS) patients with hypertension (pSS‐HT) have a significantly increased risk of cardio‐cerebrovascular events. Serum uric acid (SUA), a potential inflammatory substance, is considered to be closely related to hypertension in the general population. Our aim is to assess the association between SUA and pSS‐HT. This is a retrospective cohort study. The diagnosis of pSS is based on the American European Consensus Classification criteria. Primary outcome was incident hypertension in pSS patients. Cox regression model was used to estimate the hazard ratios (HR) and 95% CI of SUA in pSS‐HT. The authors also plotted Kaplan–Meier plots to assess the cumulative risk of first hypertension in patients with hyperuricemia and normal uric acid. In addition, the dose‐response curve was also used to discuss the relationship between SUA and pSS‐HT. Finally, three hundred and fifty‐one pSS patients were enrolled from May 2011 to May 2020, of which 166 cases developed hypertension within a mean follow‐up of 3.91 years. Univariate Cox regression demonstrated that SUA was associated with the onset of hypertension in pSS (HR: 1.005 95%Cl: 1.002–1.009). After adjusting for the potential risk factors, the relationship remained unchanged (HR: 1.003, 95%Cl: 1.001–1.005). Kaplan‐Meier survival analysis showed a statistically significant difference of hypertension risk between hyperuricemia patients and normal uric acid patients (P = .026). There was also a significant dose‐effect relationship between SUA and hypertension in pSS in dose‐response model. In this study, the authors find that SUA may be closely associated with the development of hypertension in pSS, which is also confirmed by our dose‐response model. Therefore, SUA could be considered in the management of pSS‐HT.

Clinicopathological Patterns and Outcomes in Patients with Lupus Nephritis and Hyperuricemia

A limited number of large cohort studies have reported the clinicopathological characteristics and prognosis of patients with lupus nephritis (LN) and hyperuricemia (HUA). In this retrospective cohort study, 1297 LN patients were enrolled from January 1996 to December 2011 in the First Affiliated Hospital of Sun Yat-Sen University, and HUA occurred in 649 (50.04%) of these 1297 LN patients. Compared to patients without HUA, those with HUA presented with higher blood pressure and triglyceride levels, lower hemoglobin and serum albumin levels, worse renal function, more severe hematuria and proteinuria, higher lupus activity, and more positive antiphospholipid antibody. Pathologically, HUA cases presented more crescents, a higher degree of mesangial matrix, endothelial cell proliferation, and inflammatory cell infiltration. During the 52-month follow-up, the 5-year and 10-year incidence rates of renal endpoint events were 11.1% and 19.5% in the HUA group, and 8.3% and 13.8% in the non-HUA group, respectively (p = 0.073). In addition, the 5-year and 10-year mortality rates did not differ significantly between the HUA (12.0% and 18.2%) and non-HUA (12.2% and 17.5%) groups, respectively. This study verified that HUA was not an independent risk for poor clinical outcomes, and steroids that delay the deterioration of renal function did not affect the survival of these patients.

The relationship between serum uric acid level and uric acid/creatinine ratio with chronic obstructive pulmonary disease severity (stable or acute exacerbation) and the development of cor pulmonale

BACKGROUND

There are studies reporting that uric acid elevation is a marker for hypoxemia and pulmonary hypertension secondary to some diseases.

AIM

The aim of this study is to investigate the relationship between serum uric acid level and uric acid/creatinine ratio with chronic obstructive pulmonary disease (COPD) exacerbation, hypoxemia in exacerbation and development of cor pulmonale.

METHODS

A total of 96 COPD patients who were admitted to Ondokuz Mayıs University Faculty of Medicine emergency department and Chest Diseases outpatient clinic and whose written consent was obtained were included in our study. Forty-three of these patients were in the period of exacerbation (Group 1), and 53 were in the stable period (Group 2). Complete blood count, blood biochemistry (including serum uric acid level) and arterial blood gas analysis were performed in our patients. In addition, spirometry and echocardiography findings were examined.

RESULTS

Serum uric acid level of patients in the period of exacerbation group (Group 1) was 6.97 ± 1.34 and in stable COPD group (Group 2) was 4.30 ± 1.01 (P < .05). Uric acid/creatinine ratios in Group 1 was 8.00 ± 2.06; in Group 2, it was 5.52 ± 1.57 (P < .05). In patients with hypoxemia, serum uric acid level and uric acid/creatinine ratio were significantly higher than nonhypoxemic patients (P < .05). Serum uric acid level and serum uric acid/creatinine ratio of Group 1 were significantly higher than Group 2 (P < .001). Serum uric acid level and serum uric acid/creatinine ratio of patients who developed cor pulmonale were significantly higher than patients without cor pulmonale (P < .05).

CONCLUSION

Serum uric acid level and uric acid/creatinine ratio were found to be higher in patients with exacerbation of COPD and those developing cor pulmonale. Consequently, it suggests that serum uric acid level and serum uric acid/creatinine ratio may be a stimulating laboratory test for the severity of COPD and the development of COPD induced cor pulmonale.

Serum uric acid as a sensitive concordant marker with lupus nephritis and new onset of renal damage: a prospective cohort study

OBJECTIVE

The objectives of this study are to assess serum different uric acid levels among systemic lupus erythematosus patients with or without active lupus nephritis in comparison to healthy controls and to study the relation of baseline uric acid levels to the development of new-onset renal damage in lupus nephritis.

METHODS

This is a case-control study followed by a prospective cohort of systemic lupus erythematosus (SLE) patients. Three groups were included; all were having normal kidney function, 25 SLE patients with recently diagnosed active lupus nephritis (LN), 26 SLE patients without LN, and 38 healthy controls. Serum uric acid (SUA)and serum creatinine were done for all groups; for SLE patients, 24-h protein in the urine, urinalysis, C3, C4 levels, anti-DNA, anti-ENA antibodies, SLE Disease Activity Index (SLEDAI), and SLICC/ACR damage index (SDI) evaluation were also calculated. Follow-up was done with clinical and laboratory assessment including SUA, with SLEDAI and SDI evaluation.

RESULTS

Serum uric acid was significantly higher in SLE patients with active LN than the other two groups (p < 0.05), a cutoff value of serum uric acid associated with lupus nephritis onset was 0.41 mmol/L with a sensitivity of 58% and specificity of 100%, however, C3 and C4 showed very low sensitivity and specificity. During follow-up, all patients with LN with baseline serum uric acid ≥ 0.52 mmol/L were associated with new-onset renal damage within 43 months.

CONCLUSIONS

High-serum uric acid levels showed a significant association with lupus nephritis onset and new onset of renal damage. Key Points • Serum uric acid is a cheap, rapid, and popular test available in most of the worldwide laboratories; its higher levels showed a significant association with lupus nephritis onset and new onset of renal damage • The current work is the largest study done on lupus nephritis with strict control to the confound risk factors that are associated with the increase of the uric acid levels; moreover, it is the first study to assess such relation in Saudi population • Uric acid could have a role in the pathogenesis of lupus nephritis patients and consequent renal damage.

Serum uric acid is associated with disease severity and may predict clinical outcome in patients of pulmonary arterial hypertension secondary to connective tissue disease in Chinese: a single-center retrospective study

Background

Previous studies have shown that serum uric acid (UA) levels are correlated with the severity of idiopathic pulmonary arterial hypertension (IPAH) and are predictors of disease prognosis. Still, few studies have explored the value of serum UA in pulmonary arterial hypertension secondary to connective tissue disease (CTD-PAH). This retrospective study aimed to investigate the clinical value of serum UA levels in patients with CTD-PAH.

Methods

Fifty CTD-PAH patients were enrolled in our study, from which baseline UA levels, respective variations, and additional clinical data were collected. The potential association between baseline UA level and severity of CTD-PAH was investigated. Furthermore, the relationship between baseline UA and survival rate of CTD-PAH patients, as well as between UA variations and survival rate of pulmonary hypertension secondary to connective tissue disease (CTD-PH) patients was discussed.

Results

Baseline serum UA levels were positively correlated with pulmonary vascular resistance (PVR). During the follow-up period, 3 CTD-PAH and 12 CTD-PH patients died. Kaplan-Meier survival curves showed lower survival rate in patients with hyperuricemia than in patients with normouricemia, in both groups (CTD-PAH group p = 0.041, CTD-PH group p = 0.013). Concerning serum UA variations, patients with persistent hyperuricemia showed the lowest survival rate when compared with patients with steady normouricemia (p = 0.01) or patients with decresing serum UA levels, i.e. undergoing from a status of hyperuricemia to a status of normouricemia (p = 0.023).

Conclusion

Baseline serum UA levels might predict severity of CTD-PAH. Together with baseline values, changes of uric acid level may predict the clinical prognosis of the disease.

Uric acid and kidney damage in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs; lupus nephritis (LN) is one of the most severe complications of SLE. In the kidneys, an intense inflammatory reaction affects the glomeruli and tubular interstitium. Uric acid has been considered a key molecule in the pathogenesis of some conditions such as metabolic syndrome, hypertension, and kidney disease as it is produced by injured cells and promotes immune-inflammatory responses. In this regard, high serum uric acid concentrations may be involved in the activation of some inflammatory pathways, associated with kidney damage in SLE. Therefore, the purpose of this article was to review the main physiological mechanisms and clinical data on the association between serum uric acid and kidney damage in SLE. Scientific evidence indicates that hyperuricemia has the potential to be an adjuvant in the development and progression of kidney manifestations in SLE. Uric acid may promote the activation of inflammatory pathways and the formation and deposition of autoantibodies in kidneys, leading to a reduction of glomerular filtration rate. Other potential mechanisms of this association include the presence of polymorphisms in the urate transporters, metabolic syndrome, use of some medications, and other situations associated with a reduced renal excretion of uric acid.

Serum uric acid is associated with damage in patients with systemic lupus erythematosus

Introduction

Serum uric acid levels have been reported as predictors of cardiovascular, pulmonary, neurological and renal morbidity in patients with SLE. However, their role in cumulative global damage in these patients has not yet been determined.

Objective

To determine whether serum uric acid levels are associated with new damage in patients with SLE.

Methods

This is a longitudinal study of patients with SLE from the Almenara Lupus Cohort, which began in 2012. At each visit, demographic and clinical characteristics were evaluated, such as activity (Systemic Lupus Erythematosus Disease Activity Index-2K or SLEDAI-2K) and cumulative damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index or SDI). Treatment (glucocorticoids, immunosuppressive drugs and antimalarials) was also recorded. Univariable and multivariable Cox regression models were used to determine the impact of serum uric acid levels on the risk of new damage.

Results

We evaluated 237 patients, with a mean age (SD) at diagnosis of 35.9 (13.1) years; 220 patients (92.8%) were women, and the duration of the disease was 7.3 (6.6) years. The mean SLEDAI-2K and SDI scores were 5.1 (4.2) and 0.9 (1.3), respectively. Serum uric acid level was 4.5 (1.4) mg/dL. Follow-up time was 3.1 (1.3) years, and 112 (47.3%) patients accrued damage during follow-up. In univariable and multivariable analyses, serum uric acid levels were associated with new damage (HR=1.141 (95% CI 1.016 to 1.282), p=0.026; HR=1.189 (95% CI 1.025 to 1.378), p=0.022, respectively).

Conclusion

Higher serum uric acid levels are associated with global damage in patients with SLE.

The small molecule macrophage migration inhibitory factor antagonist MIF098, inhibits pulmonary hypertension associated with murine SLE

Pulmonary arterial hypertension (PAH) is a severe complication of systemic lupus erythematosus (SLE), with unclear etiopathogenesis. We evaluated the role of macrophage migration inhibitory factor (MIF), which has been implicated in idiopathic pulmonary hypertension (PH), in SLE-associated PAH. Circulating MIF was measured in SLE patients, SLE-PAH patients, and healthy donors. In situ pulmonary artery MIF protein expression was determined in spontaneous SLE mice (MRL/lpr) and hypoxia-induced C57BL/6J mice. Daily MIF098 was administered to C57BL/6J mice, and these mice were maintained in a hypoxic chamber for 4 weeks. The right ventricular systolic pressure (RVSP) and pathological characteristics of the pulmonary artery (PA), such as hyperproliferation, muscularization, and fibrosis were then measured in each group of mice. Data were also obtained in vitro using pulmonary smooth muscle cells (PASMC) challenged with platelet-derived growth factor (PDGF)-BB or 1% O₂ hypoxia. As a result, circulating MIF was elevated in SLE-PAH patients compared with SLE patients or healthy donors. Higher RVSP SLE mice produced more MIF protein than lower RVSP SLE mice in the pulmonary artery. MIF098 decreased RVSP and inhibited distal pulmonary artery hyperproliferation, muscularization, and collagen deposition in hypoxia challenged mice. In addition, MIF098 inhibited PASMC proliferation and migration by regulating mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 (MAPK/ERK1/2) signal- and cell-cycle-related proteins. MIF098 also reduced collagen synthesis by inhibiting the TGFβ1/Smad2/Smad3 pathway in cell-based experiments. In conclusion, MIF may serve as a biomarker and a therapeutic target of SLE-associated PAH. Pharmacologic MIF antagonism may be an effective means to ameliorate SLE-PAH.

The Differential Influence of Immunological Process of Autoimmune Disease on Lipid Metabolism: A Study on RA and SLE

Metabolic parameters like uric acid, lipids and homocysteine are influenced by immunopathological mechanisms underlying the autoimmune disease processes. The current study examined the differences in these parameters and the correlation between inflammatory and metabolic variables in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients. The cross-sectional prospective study included 24 treatment-naïve patients with moderate to severe diseases-15 subjects had RA and 9 had SLE. Atherogenic index of plasma (AIP) was used to assess the cardiovascular risk of the patients. Spearman's correlation was performed to verify the relationship between inflammatory and metabolic parameters. A two-tailed P < 0.05 was considered statistically significant for all the analysis. SLE patients had higher uric acid levels, very low density lipoprotein-cholesterol, total cholesterol/high density lipoprotein-cholesterol ratio (TC/HDL-C) and logarithmic ratio of triglycerides to HDL-cholesterol (log[TG/HDL-C]) than RA. Whereas, reduced total lymphocyte count, lipoprotein(a), and low density lipoprotein cholesterol were noted in the former than latter group. Majority of the SLE patients had increased risk of cardiovascular diseases (> 0.24 AIP score) and RA patients in comparison had lower risk. Correlation among serum uric acid, lipid profile constituents and AIP was noted. The immunological process of SLE has greater impact on the metabolic parameters. Higher uric acid levels are suggestive of dysfunctional lipid profile. Understanding the implications of risk factors and its inflammatory role in autoimmune processes may assist in disease management.

Evaluation of serum uric acid level in systemic lupus erythematosus patients with normal and high pulmonary arterial hypertension

BACKGROUND

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition affected any organ system. Considering the role of uric acid as a pro-inflammatory compound in high pulmonary arterial pressure, serum levels of uric acid and its relation to severity and duration of the disease were assessed in SLE patients.

METHODS

As a cross-sectional study, 75 patients with SLE were enrolled in Imam Khomeini Hospital and Sahand Clinic. Serum uric acid level was measured by pars azmoon kit. Pearson correlation coefficient and T-test were used for statistical analysis of data.

RESULTS

The mean duration of SLE was 56.44 ± 40.57 months. High serum uric acid was observed in 13.3% of patients with SLE. Moreover, 8% of these patients had high pulmonary arterial pressure. Serum uric acid in patients with high pulmonary artery pressure was significantly higher than patients with normal pulmonary artery pressure (P < 0.01). Furthermore, a significant relation was seen between severity of SLE disease with serum uric acid level and pulmonary artery systolic pressure (P < 0.05). However, there was no significant correlation between serum uric acid level and duration of the disease (p = 0.90, r = 0.016).

CONCLUSION

According to these results, a significantly increased level of serum uric acid was observed in patients with pulmonary arterial pressure. Hence, serum uric acid level could be a prognostic marker of pulmonary arterial pressure in SLE patients which correlates with disease severity. It also would help to reduce clinical demands for echocardiography in patients with normal uric acid levels.

Factors associated with development and mortality of pulmonary hypertension in systemic lupus erythematosus patients

Objectives

This study aims to identify the factors associated with the development and mortality of pulmonary hypertension (PH) in systemic lupus erythematosus (SLE) patients.

Methods

We conducted a prospective study of SLE patients in a single tertiary center. PH was defined as a systolic pulmonary arterial pressure ≥30 mmHg on transthoracic echocardiography. We assessed potential associated factors contributing to the development and mortality of PH in SLE patients.

Results

Of 1110 patients with SLE, 48 patients were identified to have PH. Multivariable analysis indicated that pleuritis or pericarditis (odds ratio (OR) = 4.62), anti-RNP antibody (OR = 2.42), interstitial lung disease (ILD) (OR = 8.34) and cerebro-cardiovascular disease (OR = 13.37) were independently associated with the development of PH in SLE. Subgroup analysis among patients with PH demonstrated that there were no statistically significant factors associated with PH mortality in SLE.

Conclusions

The prevalence of PH was 4.3% in our cohort. There were significant associations with pleuritis or pericarditis, anti-RNP antibody, ILD, and cerebro-cardiovascular disease in SLE, which may contribute to the development of PH. However, there were no statistically significant factors associated with PH mortality in SLE.

Diagnostic criteria, severity classification and guidelines of systemic sclerosis

Several effective drugs have been identified for the treatment of systemic sclerosis (SSc). However, in advanced cases, not only their effectiveness is reduced but they may be also harmful due to their side-effects. Therefore, early diagnosis and early treatment is most important for the treatment of SSc. We established diagnostic criteria for SSc in 2003 and early diagnostic criteria for SSc in 2011, for the purpose of developing evaluation of each organ in SSc. Moreover, in November 2013, the American College of Rheumatology and the European Rheumatology Association jointly developed new diagnostic criteria for increasing their sensitivity and specificity, so we revised our diagnostic criteria and severity classification of SSc. Furthermore, we have revised the clinical guideline based on the newest evidence. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of SSc.

Determination of uric acid in biological samples by high performance liquid chromatography-electrospray ionization-tandem mass spectrometry and study on pathogenesis of pulmonary arterial hypertension in pulmonary artery endothelium cells

Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease that can lead to vascular remodelling and hypertension. Clinical diagnosis of PAH is very difficult. Uric acid (UA) can act as a biological marker for screening of PAH in patients. Multiple studies have indicated that reactive oxygen species (ROS) play an important role in the development of PAH. Thus, it is important to study the relationship between UA and ROS based on the pathogenesis of PAH. For monitoring PAH, a high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed to measure the concentration of UA from rat models and pulmonary arterial endothelial cells (PAECs) models, which were induced by monocrotaline (MCT) and hypoxia, respectively. In addition, the treatment groups were treated by N-acetyl-l-cysteine (NAC), a ROS scavenger. With the confirmation from hematoxylin-eosin (H&E) staining, the HPLC-ESI-MS/MS method was adopted to successfully analyze the concentration of UA. In this study, for the first time, thymine was used as an internal standard (I.S.) of uric acid. The results showed that the UA concentration in the PAH groups was higher than that in the normal groups, while the UA concentration in the treatment groups decreased compared to that in the PAH group (p < 0.05). It was experimentally proven that the HPLC-ESI-MS/MS method is a rapid, efficient and reliable quantitative method to detect PAH. Furthermore, our results indicated that UA and ROS have a double-regulator role.

Thymine firstly was used as an internal standard for uric acid.

Prevalence of pulmonary hypertension in systemic lupus erythematosus: a meta-analysis

BACKGROUND AND AIMS

Pulmonary hypertension (PH) has been suggested to be associated with systemic lupus erythematosus (SLE). However, the results of prevalence studies on PH in SLE vary substantially. To derive a more precise estimation on the prevalence of PH in SLE, a meta-analysis was performed.

METHODS

Relevant literatures were searched in PubMed and EMBASE until November 2017. A total of 1366 articles were obtained after searching databases, and 23 studies were finally included in the meta-analysis. Heterogeneity test was performed, and publication bias was evaluated.

RESULTS

The result of analysis in random effect model showed that the pooled prevalence was 8% (95%CI 5-12%). There was no evidence of publication bias (p = 0.51). To evaluate the stability of our results, sensitivity analyses were performed, and the results showed no significant change when any one study was excluded. Subgroup analyses demonstrated that there were significant differences in PH prevalence in SLE patients of different gender, age, regions, year of publication, and diagnostic methods.

CONCLUSIONS

PH is prevalent in SLE patients, but it was significantly different between different gender, age, regions, year of publication, and diagnostic methods.

Serological biomarkers as risk factors of SLE-associated pulmonary arterial hypertension: a systematic review and meta-analysis

Objective This article aims to determine the serological biomarkers which can be considered as risk factors of systemic lupus erythematosus (SLE)-associated pulmonary arterial hypertension by a systematic review and meta-analysis. Methods This study was conducted in accordance with the PRISMA statement. The search database included MEDLINE, EMBASE, Cochrane Library and Scopus. The Newcastle-Ottawa scale was used for the quality assessment. The odds ratio was the primary measure of effect of the risk factors. Results Twelve studies were included in this meta-analysis. The results identified the anti-RNP antibody and anti-Sm antibody as risk factors for SLE-associated pulmonary arterial hypertension with the pooled odds ratios 3.68 (95% confidence interval 2.04-6.63, P < 0.0001) and 1.71 (95% confidence interval 1.06-2.76, P = 0.03), respectively. Conclusion Pulmonary arterial hypertension is a serious complication of SLE with a worse prognosis than SLE patients without pulmonary arterial hypertension. The early recognition of pulmonary arterial hypertension with transthoracic echocardiography routinely performed in SLE patients with risk factors is necessary, especially in Asian patients.

Levels of uric acid may predict the future development of pulmonary hypertension in systemic lupus erythematosus: a seven-year follow-up study

OBJECTIVE

The objective of this paper is to assess whether pulmonary hypertension (PH) may be detected at one point in time or longitudinally predicted by serum uric acid (sUA) levels in systemic lupus erythematosus (SLE).

METHODS

We conducted a post-hoc analysis of a long-term followed cohort of Mexican SLE patients. Echocardiography-based definitions of PH by the ESC/ERS/ISHLT and its associations with clinical and laboratory data on enrollment were studied. Especially, the impact that sUA levels at baseline may have on the future development of PH in patients with normal pulmonary artery systolic pressure (PASP) was explored.

RESULTS

Out of the 156 SLE patients originally enrolled in the cohort, 44 met the inclusion criteria for the present study and were grouped as having (n =10) or not having (n = 34) PH. At baseline, sUA levels of 5.83 ± 1.79 and 5.82 ± 1.97 mg/dl (p = ns) were found in patients with and without PH, respectively. No association between PASP and other markers was found. In patients with normal PASP, the presence of sUA ≥ 7 mg/dl at baseline predicted future development of PH (relative risk 8.5, 1.0009 to 72; p = 0.04).

CONCLUSION

In SLE, sUA levels at one point in time are useless to detect PH. However, steady hyperuricemia may predict the future development of PH in patients with normal PASP at baseline.

Pulmonary hypertension in systemic lupus erythematosus: an independent predictor of patient survival

BACKGROUND/AIMS

We investigated whether transthoracic echocardiography-suspected pulmonary hypertension (PH) affects survival in systemic lupus erythematosus (SLE) patients and examined factors associated with PH occurrence and survival.

METHODS

This retrospective single-center study included 154 Korean SLE patients fulfilling the American College of Rheumatology criteria (January 1995 to June 2013). Student t test, Mann-Whitney U test, Kaplan-Meier curves, and log-rank tests were used for comparisons.

RESULTS

A total of 35 SLE patients with PH (SLE/PH+) and 119 without PH (SLE/PH-) were analyzed. Higher percentages of interstitial lung disease, Raynaud's phenomenon (RP), World Health Organization functional classification III/IV, and cardiomegaly were found in SLE/PH+ compared to SLE/PH-. Furthermore, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index was significantly higher in SLE/PH+ (2.46 ± 1.245 vs. 1.00 ± 1.235), whereas survival rates were significantly higher in SLE/PH- in log-rank tests (p = 0.001). In multivariate analysis, the adjusted mortality hazard ratio (HR) for SLE/PH+ patients was 3.10. Subgroup analysis demonstrated a higher percentage of lupus nephritis in the SLE/PH+ patients who died (p = 0.039) and low complement-3 levels (p = 0.007). In univariate analysis, the mortality HR for SLE/PH+ patients with lupus nephritis was 4.62, whereas the presence of RP decreased the mortality risk in multivariate analysis; adjusted HR, 0.10.

CONCLUSIONS

PH is an independent factor predicting survival in SLE patients. The presence of lupus nephritis resulted in an increased trend for mortality, whereas coexistence of RP was associated with a better survival prognosis in SLE/PH+ patients.