Association of serum uric acid with lupus nephritis in systemic lupus erythematosus

Serum Uric Acid Combined with Homocysteine as a Predictive Biomarker of Lupus Nephritis

Serum uric acid (UA) and homocysteine (Hcy) are potential biomarkers of systemic lupus erythematosus (SLE). In this study, the expressions of UA and Hcy in SLE patients and the predictive value of these two parameters for lupus nephritis (LN) were studied. A total of 476 SLE patients were recruited to this case-control study, of which 176 SLE patients diagnosed with LN and 300 without LN. Serum UA and Hcy levels were analyzed. Multivariate logistic regression analysis was used to evaluate the relationship between serum UA and Hcy and LN. The receiver operating characteristic (ROC) curves were used to predict the role of combination of serum UA and Hcy in LN. We found that serum UA and Hcy levels in SLE patients with LN were significantly higher than those in controls (p<0.05). Multivariate logistic regressions showed that serum UA (OR+=+1.003, 95+% CI: 1.001-1.006, p+=+0.003), apolipoprotein B (Apo B) (OR+=+21.361, 95+% CI: 2.312-195.373, p+=+0.007) and Hcy (OR+=+1.042, 95+% CI: 1.011-1.080, p+=+0.014) were independent markers of LN. Combined serum UA and Hcy revealed a better result (AUC+=+0.718, 95+% CI: 0.670-0.676, p<0.001) in prediction of LN compared to that of the serum UA (AUC+=+0.710) and Hcy (AUC+=+0.657) independently. In conclusion, serum UA and Hcy could be predictive biomarkers of LN, and joint detection of serum UA and Hcy might be useful in the clinical setting.

Deep learning model to predict lupus nephritis renal flare based on dynamic multivariable time-series data

OBJECTIVES

To develop an interpretable deep learning model of lupus nephritis (LN) relapse prediction based on dynamic multivariable time-series data.

DESIGN

A single-centre, retrospective cohort study in China.

SETTING

A Chinese central tertiary hospital.

PARTICIPANTS

The cohort study consisted of 1694 LN patients who had been registered in the Nanjing Glomerulonephritis Registry at the National Clinical Research Center of Kidney Diseases, Jinling Hospital from January 1985 to December 2010.

METHODS

We developed a deep learning algorithm to predict LN relapse that consists of 59 features, including demographic, clinical, immunological, pathological and therapeutic characteristics that were collected for baseline analysis. A total of 32 227 data points were collected by the sliding window method and randomly divided into training (80%), validation (10%) and testing sets (10%). We developed a deep learning algorithm-based interpretable multivariable long short-term memory model for LN relapse risk prediction considering censored time-series data based on a cohort of 1694 LN patients. A mixture attention mechanism was deployed to capture variable interactions at different time points for estimating the temporal importance of the variables. Model performance was assessed according to C-index (concordance index).

RESULTS

The median follow-up time since remission was 4.1 (IQR, 1.7-6.7) years. The interpretable deep learning model based on dynamic multivariable time-series data achieved the best performance, with a C-index of 0.897, among models using only variables at the point of remission or time-variant variables. The importance of urinary protein, serum albumin and serum C3 showed time dependency in the model, that is, their contributions to the risk prediction increased over time.

CONCLUSIONS

Deep learning algorithms can effectively learn through time-series data to develop a predictive model for LN relapse. The model provides accurate predictions of LN relapse for different renal disease stages, which could be used in clinical practice to guide physicians on the management of LN patients.

Association between serum uric acid level and systemic lupus erythematosus kidney outcome: An observational study in Southern Chinese population and a meta-analysis

OBJECTIVE

The study aimed to explore the effect of serum uric acid (SUA) level on the progression of kidney function in systemic lupus erythematosus (SLE) patients.

METHODS

A total of 123 biopsy-proven lupus nephritis (LN) patients were included in this retrospective observational study. Cox proportional hazard regression analyses as well as restricted cubic spline analyses were performed to identify predictors of renal outcome in LN patients. We also performed a systematic review and meta-analysis for SUA and overall kidney outcomes in SLE patients.

RESULTS

Based on the laboratory tests at renal biopsy, 72 (58.5%) of the 123 patients had hyperuricemia. The median (IQR) follow-up duration was 3.67 years (1.79-6.63 years), and a total of 110 (89.4%) patients experienced progression of LN. Increased serum uric acid level, whether analyzed as continuous or categorical variable, was associated with higher risk of LN progression in Cox proportional hazard regression model (hazard ratio [HR]: 1.003, 95% confidence interval [CI]: 1.001-1.005; HR: 1.780, 95% CI: 1.201-2.639, respectively). This relationship maintained in women (HR: 1.947, 95% CI: 1.234-3.074) but not men (HR: 2.189, 95% CI: 0.802-5.977). The meta-analysis showed a similar result that both continuous and categorical SUA were positively associated with the risk of kidney function progression in LN (weighted mean difference [WMD]: 1.73, 95% CI: 0.97-2.49; odds ratio [OR]: 1.55, 95% CI: 1.20-2.01, respectively).

CONCLUSIONS

Our study found overall and especially in women that higher SUA in LN patients were associated with increased risk of renal progression. Meta-analysis yielded consistent results. Future studies are required to establish if uric acid can be used as a biomarker for risk assessment and/or as a novel therapeutic target in SLE.

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.

The Relationship between Hepatic Myeloid-Derived Suppressor Cells and Clinicopathological Parameters in Patients with Chronic Liver Disease

Myeloid-derived suppressor cells (MDSCs) have attracted attention due to their important role in inflammation. Several studies have investigated the involvement of MDSCs in chronic liver disease. However, due to the difference of MDSC phenotypes, patient types, and sample sources among the studies, the results are inconsistent and controversial. We took advantage of a large well-defined cohort of 98 (24 patients with CHB, 18 with NAFLD, 13 with HCC, 16 with PBC, and 27 with AIH) patients with liver inflammation and 12 healthy controls to investigate the expression of MDSCs, and the relationships between the expression of hepatic MDSCs and the clinical characteristics were analyzed. We found that the expression of CD11b+CD33+ MDSCs is closely related to chronic liver disease and positively correlated with clinical parameters such as ALT, AST, and globulin. Ultimately, the present study suggests that hepatic CD11b+CD33+ MDSCs are increased in HCC and AIH and positively correlate with the liver stages of hepatitis activity and liver fibrosis stage.

Low expression of estrogen receptor β in renal tubular epithelial cells may cause hyperuricemia in premenopausal patients with systemic lupus erythematosus

We investigated the impact of estrogen receptor (ER) expression in renal tubular epithelial cells on serum uric acid (UA) levels in premenopausal patients with systemic lupus erythematosus (SLE). Thirty patients underwent renal biopsy: 18 with SLE (LN group) and 12 with IgA nephritis (IgAN group). ERs (ERα and ERβ) in renal tubular epithelial cells were measured using immunohistochemistry. The ER expression levels of the two groups were compared, and the relationship between the expression of ERs and serum UA levels was analyzed. Mean serum UA levels in the LN group were significantly higher than those of the IgA nephropathy group, while the mean creatinine levels and GFRs of the two groups were similar. Pathological changes in the LN group were significantly more severe than those in the IgAN group. ERβ was expressed in renal tubular epithelial cells in both groups, but not in the glomeruli. ERβ expression in the LN group was significantly lower than that in the IgAN group. ERβ expression scores significantly negatively correlated with serum UA levels. These findings suggest that the expression of ERβ in premenopausal female SLE patients may cause hyperuricemia, and may subsequently promote glomerular damage, suggesting that ERβ may be involved in UA excretion.

Serum uric acid as a predictor for nephritis in Egyptian patients with systemic lupus erythematosus

OBJECTIVE

Lupus nephritis (LN) is closely associated with hyperuricemia, and uric acid is considered a risk factor for renal involvement in systemic lupus erythematosus (SLE). This study aimed to examine the association between serum uric acid (SUA) level and LN development and progression in SLE patients with normal renal function.

METHODS

A total of 60 SLE patients with normal renal function from Ain Shams University Hospital were selected and assigned to group 1 (30 patients with LN) and group 2 (30 patients without LN). All patients were subjected to history taking, clinical examination, disease activity assessment based on SLE disease activity index (SLEDAI) and renal SLEDAI (SLEDAI-R) scores, and laboratory investigations, including as SUA, complete blood count, blood urea nitrogen (BUN), serum creatinine, creatinine clearance, urine analysis, protein/creatinine ratio, 24-h urinary protein excretion, Antinuclear antibodies (ANA), anti-dsDNA antibody, and serum complement (C3, C4).

RESULTS

Disease duration, SLEDAI score, and SUA level were higher in group 1 than in group 2 (p < 0.001). SUA level was positively correlated with SLEDAI and SLEDAI-R scores, proteinuria, urinary casts, renal biopsy class, disease activity and chronicity indices, BUN level, and serum creatinine level but was negatively correlated with creatinine clearance (p < 0.05). SUA was a predictor of LN development in SLE patients (sensitivity, 83.3%; specificity, 70%).

CONCLUSION

SUA is associated with the development of lupus nephritis in patients with normal kidney function also SUA in-dependently correlated with disease activity and chronicity in LN.

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.

Atherogenic Index of Plasma in Women with Rheumatoid Arthritis and Systemic Lupus Erythematosus: A 10-Year Potential Predictor of Cardiovascular Disease

BACKGROUND

Women with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are at high risk of cardiovascular diseases (CVD). The atherogenic index of plasma (AIP) is a new marker for the assessment of CVD.

OBJECTIVE

This study aimed to determine the predictive value of AIP with long-term CVD risk among women with RA and SLE.

METHODS

This is a cross-sectional study of 99 RA and 59 SLE women. Demographic, clinical, and biochemical data were obtained, and disease activities were calculated. For each patient, the longterm risk of CVD was calculated using the Framingham risk score (FRS); AIP was derived according to the logarithmic (triglycerides/high-density lipoproteins cholesterol).

RESULTS

The mean age of the RA and SLE patients was 47.97 ± 8.78 and 36.75 ± 9.09 years, respectively. The median (interquartile range) of AIP values in RA and SLE patients were 0.34 (-0.15, 1.02) and 0.33 (-0.53, 0.96), respectively, while FRS values of RA patients and SLE patients were 6.38 ± 5.58 and 4.86 ± 4.5, respectively (p >0.05). There was a moderate correlation between AIP and FRS in RA and SLE patients (r=0.42, p=0.002 and r=0.33, p=0.007, respectively). According to the multivariate regression analyses, we found that AIP value is an independent factor for FRS in RA (β: 4.13, 95% confidence interval; 1.71, 6.18; p=0.008) and in SLE patients (β: 6.19, 95% confidence interval; 2.58, 9.81; p<0.001).

CONCLUSIONS

We reported that AIP can be used as an independent indicator for long-term CVD risk in RA and SLE patients.

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 Renal Prognosis of Lupus Nephritis in Women but not in Men

Lupus nephritis (LN) is a major complication of systemic lupus erythematosus. Early intervention in lupus nephritis improves prognosis. There is an association between hyperuricemia and lupus nephritis; nevertheless, the sex-specific role of uric acid in lupus nephritis remains unclear. We retrospectively analyzed 578 patients diagnosed with LN by renal biopsy. We determine the relationship of serum uric acid to progression of LN using Kaplan–Meier survival analyses and Cox proportional hazards models. The primary end point was LN progression defined as the initiation of dialysis or kidney transplantation. Men had higher mean serum uric acid levels than did women. Every 1 mg/dL increase in baseline uric acid level increased the risk of LN progression by 15.1%. The serum uric acid level was an independent risk factor for LN progression in women (hazard ratio [HR], 1.158; confidence interval [CI], 1.018–1.317; p = 0.028) but not in men (HR, 1.499; CI, 0.964–2.331; p = 0.072). Sensitivity analysis involving serum uric acid terciles generated consistent and robust results. Serum uric acid level was an independent risk factor for LN progression in women but not in men.

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.

Elevated uric acid levels in premenopausal female systemic lupus erythematosus patients: Association with potential or existing renal damage

Do premenopausal female systemic lupus erythematosus (SLE) patients have a low incidence of hyperuricaemia (HU) as healthy premenopausal females? As of yet, there have been few studies. This study aims to investigate the serum uric acid (UA) levels of premenopausal female SLE patients and the associated clinical risk factors. 107 premenopausal female SLE patients were divided into two groups: the high UA SLE group (n = 45) and the normal UA SLE group (n = 62). In total, 50 age-matched healthy premenopausal females served as the control group. Serum UA concentration, kidney damage index, lupus index, disease activity score of lupus and serum lipid index were collected and compared between the SLE subgroups. Binary logistic regression and multiple linear regression analyses were used to analyse the association of high UA levels with clinical features. The mean UA level of the SLE group was significantly higher than that of the control group (509.73 ± 150.28 μmol/L vs 296.78 ± 69.87 μmol/L, P < 0.001), as was the incidence of HU (42.06% vs 14.00%, P = 0.01). The UA levels of the high UA SLE group and the normal UA SLE group were 515.91 ± 120.64 μmol/L and 245.71 ± 63.18 μmol/L, respectively, which was statistically significant ( P < 0.001). None of the patients with HU had current or previous gout attacks. The frequency of patients with renal manifestations in the high UA SLE group was significantly higher than that in the normal UA SLE group (χ2 = 26.278, P < 0.001). In the SLE group, the medications azathioprine and cyclosporine were not associated with HU ( P = 0.689), as analysed by binary linear regression. Using multiple linear regression analysis, it was found that urinary blood ( P = 0.048), creatinine ( P = 0.016), triglycerides ( P = 0.029), peripheral white blood cells ( P = 0.007) and renal manifestation ( P < 0.001) were associated with HU in the SLE group. Our results demonstrate that premenopausal SLE patients had higher levels of UA than healthy premenopausal females, which may be associated with potential or existing renal damage.

Lupus nephritis pathology prediction with clinical indices

Effective treatment of lupus nephritis and assessment of patient prognosis depend on accurate pathological classification and careful use of acute and chronic pathological indices. Renal biopsy can provide most reliable predicting power. However, clinicians still need auxiliary tools under certain circumstances. Comprehensive statistical analysis of clinical indices may be an effective support and supplementation for biopsy. In this study, 173 patients with lupus nephritis were classified based on histology and scored on acute and chronic indices. These results were compared against machine learning predictions involving multilinear regression and random forest analysis. For three class random forest analysis, total classification accuracy was 51.3% (class II 53.7%, class III&IV 56.2%, class V 40.1%). For two class random forest analysis, class II accuracy reached 56.2%; class III&IV 63.7%; class V 61%. Additionally, machine learning selected out corresponding important variables for each class prediction. Multiple linear regression predicted the index of chronic pathology (CI) (Q² = 0.746, R² = 0.771) and the acute index (AI) (Q² = 0.516, R² = 0.576), and each variable’s importance was calculated in AI and CI models. Evaluation of lupus nephritis by machine learning showed potential for assessment of lupus nephritis.

The prevalence, subtypes and associated factors of hyperuricemia in lupus nephritis patients at chronic kidney disease stages 1-3

There is a high prevalence of hyperuricemia (HUA) in the chronic kidney disease (CKD) population. However, there's a dearth of research on HUA's prevalence, subtypes, early detection, and treatment strategies of HUA in lupus nephritis (LN) patients. The aim of this study is to address these knowledge gaps. LN patients presenting to the Department of Nephrology at Shanghai Rui Jin Hospital from January 2011 to January 2016 were recruited. The effective sample size was derived using the power analysis. The demographic, clinical and laboratory characteristics of the LN patients with HUA were compared with those of patients without HUA. Two statistical models for analyzing HUA were built and compared using the receiver operating characteristic (ROC) curve analysis. The total prevalence of HUA in the cohort was 40.11%. The subtypes of HUA included urate underexcretion-type, overproduction-type and combined-type, which proportion being 67.7%, 9.7% and 22.6% respectively. The CKD stage was closely associated with the prevalence of HUA in patients with LN. The other significant associated factors were hypertension, triglycerides, serum creatinine, serum albumin, hemoglobin, parathyroid hormone, phosphorus, calcium, etc. The statistical algorithm successfully identified LN patients at risk of HUA. In conclusion, there was a high prevalence of HUA in LN patients at CKD stages 1-3, and renal underexcretion hyperuricemia was the most prevalent subtype. The occurrence of HUA in LN may be related to renal insufficiency, metabolic disorder and lupus itself. Early care coordination programs can employ risk models to improve HUA prevention and target interventions in LN patients.

Hyperuricemia in systemic lupus erythematosus: is it associated with the neuropsychiatric manifestations of the disease?

OBJECTIVES

To assess the association between hyperuricemia and different neuropsychiatric manifestations and stroke risk factors in systematic lupus erythematosus (SLE) patients.

METHODS

This study was conducted on 204 SLE patients who were admitted to a tertiary referral center. A standardized questionnaire was completed for all the participants and the medical records were reviewed regarding the occurrence of arterial or venous thrombotic events, stroke, seizure, depression, headache, psychosis, and peripheral neuropathy. In addition blood samples were drawn to obtain serum uric acid, triglyceride (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and total cholesterol levels.

RESULTS

Hyperuricemia (serum uric acid ≥6mg/dl for women and ≥7mg/dl for men) was detected in 16.1% of SLE patients and was significantly associated with the occurrence of stroke (OR, 2.38; 95%CI, 1.2-7.24), and peripheral neuropathy (OR, 3.49; 95% CI, 1.52-12.23), independent of hypertension and hyperlipidemia. Hyperuricemia was also significantly associated with hypertension (OR, 7.76; 95% CI, 2.72-15.76), hyperlipidemia (OR, 5.05; 95% CI, 1.59-11.32), and history of arterial thrombosis (OR, 4.95; 95% CI, 1.98-15.34), independent of age and body mass index.

CONCLUSIONS

Hyperuricemia in SLE patients is independently associated with the occurrence of stroke and peripheral neuropathy. It is also independently associated with hypertension, hyperlipidemia, and history of arterial thrombosis, which are the major stroke and myocardial infarction risk factors in SLE patients.

[Hyperuricemia in systemic lupus erythematosus: is it associated with the neuropsychiatric manifestations of the disease?]

OBJECTIVES

To assess the association between hyperuricemia and different neuropsychiatric manifestations and stroke risk factors in systematic lupus erythematosus (SLE) patients.

METHODS

This study was conducted on 204 SLE patients who were admitted to a tertiary referral center. A standardized questionnaire was completed for all the participants and the medical records were reviewed regarding the occurrence of arterial or venous thrombotic events, stroke, seizure, depression, headache, psychosis, and peripheral neuropathy. In addition blood samples were drawn to obtain serum uric acid, triglyceride (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and total cholesterol levels.

RESULTS

Hyperuricemia (serum uric acid ≥ 6mg/dl for women and ≥ 7mg/dl for men) was detected in 16.1% of SLE patients and was significantly associated with the occurrence of stroke (OR, 2.38; 95%CI, 1.2-7.24), and peripheral neuropathy (OR, 3.49; 95% CI, 1.52-12.23), independent of hypertension and hyperlipidemia. Hyperuricemia was also significantly associated with hypertension (OR, 7.76; 95% CI, 2.72-15.76), hyperlipidemia (OR, 5.05; 95% CI, 1.59-11.32), and history of arterial thrombosis (OR, 4.95; 95% CI, 1.98-15.34), independent of age and body mass index.

CONCLUSIONS

Hyperuricemia in SLE patients is independently associated with the occurrence of stroke and peripheral neuropathy. It is also independently associated with hypertension, hyperlipidemia, and history of arterial thrombosis, which are the major stroke and myocardial infarction risk factors in SLE patients.

Hyperuricemia and chronic kidney disease: an enigma yet to be solved

The role of uric acid (UA) on the pathogenesis and progression of chronic kidney disease (CKD) remains controversial. Experimental and clinical studies indicate that UA is associated with several risk factors of CKD including diabetes, hypertension, oxidative stress, and inflammation and hyperuricemia could be considered as a common dominator linking CKD and cardiovascular disease. Notably, the impact of serum UA levels on the survival of CKD, dialysis patients, and renal transplant recipients is also a matter of debate, as there are conflicting results from clinical studies. At present, there is no definite data whether UA is causal, compensatory, coincidental or it is only an epiphenomenon in these patients. In this article, we attempt to review and elucidate the dark side of this old molecule in CKD and renal transplantation.

Review of hyperuricemia as new marker for metabolic syndrome

Hyperuricemia has long been established as the major etiologic factor in gout. In recent years, a large body of evidence has accumulated that suggests that hyperuricemia may play a role in the development and pathogenesis of a number of metabolic, hemodynamic, and systemic pathologic diseases, including metabolic syndrome, hypertension, stroke, and atherosclerosis. A number of epidemiologic studies have linked hyperuricemia with each of these disorders. In some studies, therapies that lower uric acid may prevent or improve certain components of the metabolic syndrome. There is an association between uric acid and the development of systemic lupus erythematosus; the connection between other rheumatic diseases such as rheumatoid arthritis and osteoarthritis is less clear. The mechanism for the role of uric acid in disorders other than gout is not well established but recent investigations point towards systemic inflammation induced by urate, as the major pathophysiological event common to systemic diseases, including atherosclerosis.

Coronary artery dilation among patients with paediatric-onset systemic lupus erythematosus

OBJECTIVES

This study aimed to evaluate increased coronary artery dimensions in patients with paediatric-onset systemic lupus erythematosus (SLE) in comparison with healthy controls, and to identify risk factors associated with increased coronary artery dimensions in the SLE patients.

METHODS

As part of a longitudinal cohort study of coronary artery disease (CAD) in paediatric-onset SLE, 83 children with SLE and 36 healthy controls were enrolled for a cross-sectional analysis. Their coronary artery diameters were measured by echocardiography while their body mass index (BMI), blood pressure, and other cardiovascular factors were recorded. The age at diagnosis, serum uric acid (UA) and creatinine levels, and other lupus-related factors were further evaluated in SLE patients. Data were analysed using linear regression.

RESULTS

Mean body surface area (BSA)-adjusted dimensions of the left coronary artery (LCA) and right coronary artery (RCA) were significantly larger in SLE patients than in controls (both p < 0.001). The age at diagnosis, BMI, and serum UA and creatinine levels were associated with LCA and RCA diameters. There were no correlations between the coronary artery diameters and blood pressure, SLE duration, SLE Disease Activity Index (SLEDAI), C-reactive protein (CRP), C3, C4, anti-double-stranded-DNA (anti-dsDNA), or lipid profile. In multivariate analysis, serum UA level, age at diagnosis, and BMI were consistently associated with coronary artery dimensions (p < 0.001, p = 0.008, and p = 0.006 for LCA; p = 0.020, 0.013, and 0.008 for RCA).

CONCLUSIONS

Increased coronary artery diameters were found in children with SLE and were associated with higher serum UA levels. The pathogenic mechanisms warrant further investigation.

Associations of serum urea, creatinine and uric acid with clinical and laboratory features in patients with systemic lupus erythematosus

The aim of this study is to investigate the associations of serum urea, creatinine and uric acid levels with clinical and laboratory characteristics, independent of lupus renal involvement in SLE patients. A total of 191 SLE patients were included in the present study. Some clinical and laboratory characteristics of the patients were obtained by medical record review. The results showed that serum urea, creatinine and uric acid levels seemed to be associated with several clinical and laboratory characteristics of SLE. However, multivariate logistical regression analysis indicated that increasing serum urea levels were positively associated with disease duration and thrombocytopenia, but negatively with arthritis and skin rash. Compared with quartile 1 of urea, the ORs of quartile 2, quartile 3 and quartile 4 were, respectively, 1.008 (0.997-1.015, P = 0.189), 1.010 (1.001-1.019, P = 0.038) and 1.014 (1.004-1.024, P = 0.008) with increasing disease duration; 1.912 (0.516-7.088, P = 0.332), 10.126 (2.771-36.997, P = 0.000) and 5.583 (1.285-24.266, P = 0.022) with thrombocytopenia; 0.864 (0.331-2.254, P = 0.765), 0.516 (0.18-1.475, P = 0.217) and 0.162 (0.047-0.557, P = 0.004) with arthritis; and 0.342 (0.135-0.868, P = 0.024), 0.215 (0.074-0.622, P = 0.005) and 0.332 (0.097-1.13, P = 0.078) with skin rash. Increasing serum creatinine levels were positively associated with sex, disease duration and SLEDAI, but negatively with skin rash. Compared with quartile 1 of creatinine, the ORs of quartile 2, quartile 3 and quartile 4 were, respectively, 2.993 (0.282-31.74, P = 0.363), 7.937 (0.861-73.18, P = 0.068) and 13.411 (1.32-36.246, P = 0.028) with male, 1.011 (1.002-1.02, P = 0.017), 1.002 (0.991-1.013, P = 0.684) and 1.018 (1.008-1.028, P = 0.001) with increasing disease duration; 1.112 (1.006-1.228, P = 0.038), 1.065 (0.959-1.183, P = 0.239) and 1.140 (1.022-1.272, P = 0.019) with increasing SLEDAI; and 0.303 (0.119-0.771, P = 0.012), 0.282 (0.104-0.76, P = 0.012) and 0.174 (0.052-0.584, P = 0.005) with skin rash. Increasing serum uric acid levels were only positively associated with erythrocytopenia. Compared with quartile 1 of uric acid, the ORs of quartile 2, quartile 3 and quartile 4 were, respectively, 0.910 (0.37-2.239, P = 0.837), 2.147 (0.901-5.116, P = 0.085) and 3.079 (1.211-7.828, P = 0.018) with erythrocytopenia. The present study demonstrated that, except for reflecting renal function, serum urea, creatinine and uric acid exert separate clinical significances in SLE.