Systemic lupus erythematosus in a multiethnic US cohort LUMINA LI: Anaemia as a predictor of disease activity and damage accrual

Prediction model for developing neuropsychiatric systemic lupus erythematosus in lupus patients

OBJECTIVE

This study aimed to construct a predictive model for assessing the risk of development of neuropsychiatric systemic lupus erythematosus (NPSLE) among patients with SLE based on clinical, laboratory, and meteorological data.

METHODS

A total of 2232 SLE patients were included and were randomly assigned into training and validation sets. Variables such as clinical and laboratory data and local meteorological data were screened by univariate and least absolute shrinkage and selection operator (LASSO) logistic regression modelling. After 10-fold cross-validation, the predictive model was built by multivariate logistic regression, and a nomogram was constructed to visualize the risk of NPSLE. The efficacy and accuracy of the model were assessed by receiver operating characteristic (ROC) curve and calibration curve analysis. Net clinical benefit was assessed by decision curve analysis.

RESULTS

Variables that were included in the predictive model were anti-dsDNA, anti-SSA, lymphocyte count, hematocrit, erythrocyte sedimentation rate, pre-albumin, retinol binding protein, creatine kinase isoenzyme MB, Nterminal brain natriuretic peptide precursor, creatinine, indirect bilirubin, fibrinogen, hypersensitive C-reactive protein, CO, and mild contamination. The nomogram showed a broad prediction spectrum; the area under the curve (AUC) was 0.895 (0.858-0.931) for the training set and 0.849 (0.783-0.916) for the validation set.

CONCLUSION

The model exhibits good predictive performance and will confer clinical benefit in NPSLE risk calculation. Key Points • Clinical, laboratory, and meteorological data were incorporated into a predictive model for neuropsychiatric systemic lupus erythematosus (NPSLE) in SLE patients. • Anti-dsDNA, anti-SSA, LYM, HCT, ESR, hsCRP, IBIL, PA, RBP, CO, Fib, NT-proBNP, Crea, CO, and mild contamination are predictors of the development of NPSLE and may have potential for research. • The nomogram has good predictive performance and clinical value and can be used to guide clinical diagnosis and treatment.

Differential parameters between activity flare and acute infection in pediatric patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) patients are vulnerable to infections. We aim to explore the approach to differentiate active infection from disease activity in pediatric SLE patients. Fifty pediatric SLE patients presenting with 185 clinical visits were collected. The associations between both clinical and laboratory parameters and the outcome groups were analyzed using generalized estimating equations (GEEs). These 185 visits were divided into 4 outcome groups: infected-active (n = 102), infected-inactive (n = 11), noninfected-active (n = 59), and noninfected-inactive (n = 13) visits. Multivariate GEE (generalized estimating equation) analysis showed that SDI, SLEDAI-2K, neutrophil‐to‐lymphocyte ratio (NLR), hemoglobin, platelet, RDW-to-platelet ratio (RPR), and C3 are predictive of flare (combined calculated AUC of 0.8964 and with sensitivity of 82.2% and specificity of 90.9%). Multivariate GEE analysis showed that SDI, fever temperature, CRP, procalcitonin (PCT), lymphocyte percentage, NLR, hemoglobin, and renal score in SLEDAI-2k are predictive of infection (combined calculated AUC of 0.7886 and with sensitivity of 63.5% and specificity of 89.2%). We can simultaneously predict 4 different outcome with accuracy of 70.13% for infected-active group, 10% for infected-inactive group, 59.57% for noninfected-active group, and 84.62% for noninfected-inactive group, respectively. Combination of parameters from four different domains simultaneously, including inflammation (CRP, ESR, PCT), hematology (Lymphocyte percentage, NLR, PLR), complement (C3, C4), and clinical status (SLEDAI, SDI) is objective and effective to differentiate flares from infections in pediatric SLE patients.

Understanding Risk Factors for Poor Outcomes in a Multiethnic Longitudinal Cohort: The LUMINA (Lupus in Minorities: Nature vs. Nurture) Experience (LUMINA LXXXII)

The Lupus in Minorities: Nature Vs Nurture (LUMINA) cohort has placed Hispanics on the lupus map in the United States. Texan Hispanic and African American patients experience, overall, worse outcomes than the Caucasian and Puerto Rican Hispanic patients. The genetic component of ethnicity is important early in the disease course whereas socioeconomic factors become more important subsequently. The role of hydroxychloroquine in preventing damage accrual and reducing mortality in lupus patients is a major contribution of LUMINA.

Frequencies and predictors of the Lupus Low Disease Activity State and remission in treatment-naïve patients with systemic lupus erythematosus

Objectives

To evaluate the attainability of Lupus Low Disease Activity State (LLDAS) and definitions of remission in SLE (DORIS) in a treatment-naïve cohort of SLE.

Methods

LLDAS5 was defined as LLDAS with a prednisone dose ≤5 mg/day. There were four definitions in DORIS: clinical remission on treatment (RONT), complete RONT, clinical remission off treatment (ROFT) and complete ROFT. The treatment-naïve patients from Peking University First Hospital SLE cohort were enrolled. The time to each state and their annual cumulative probabilities were estimated. The frequencies of patients who achieved each component of LLDAS or DORIS during follow-up were determined. The predictors of time to each state were identified.

Results

A total of 218 patients were included, with a median follow-up of 4.48 years. Respectively, 190 (87.2%), 160 (73.4%), 148 (67.9%), 94 (43.1%), 23 (10.6%) and 18 (8.3%) patients achieved LLDAS, LLDAS5, clinical RONT, complete RONT, clinical ROFT and complete ROFT. The median time to LLDAS, LLDAS5, clinical RONT and complete RONT were 1.4, 2.3, 2.6 and 4.7 years, respectively. Positive anti-dsDNA, RP and anaemia were significantly associated with prolonged time to LLDAS, LLDAS5 or clinical RONT.

Conclusion

Our data confirmed that LLDAS is an attainable early treatment target for SLE. Though with more difficulty, RONT can be achieved in two-thirds of our patients. ROFT may not be an ideal treatment target at present as it is only attained in few patients.

Association of Anemic Hypoxia and Increased Pulmonary Artery Systolic Pressure in Patients With Systemic Lupus Erythematosus

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a rare but serious complication of systemic lupus erythematosus (SLE). Chronic hypoxia is known to cause PAH resulting from pulmonary vascular remodeling. We investigated the association between anemic hypoxia and PAH in SLE patients.

METHODS

Systolic pulmonary artery pressure (PAP) was measured in 132 SLE patients by echocardiography. Increased PAP was defined as resting PAP > 40 mm Hg. Oxygen delivery (DO2) was estimated as the product of cardiac output and arterial oxygen content.

RESULTS

Of 132 patients, 17 (12.9%) had increased PAP, and these patients had significantly lower DO2 values than patients with normal PAP (P = 0.002). The DO2 values inversely correlated with PAP values (γ = -0.308, P < 0.001) and plasma N-terminal pro-brain natriuretic peptide levels (γ = -0.323, P = 0.001), but positively correlated with hemoglobin levels (γ = 0.402, P < 0.001). Compared to those with normal PAP, patients with increased PAP had significantly longer durations of anemia over the preceding 6-24 months. Patients with anemia of longer durations (≥3 months) in the preceding 6 months had a higher risk of increased PAP compared to those with shorter durations (P < 0.001). When SLE patients were divided into 3 groups according to hemoglobin and PAP, serum interleukin-6 (IL-6) levels increased across groups with higher PAP (P = 0.001 for trend), but decreased across tertiles of hemoglobin levels (P = 0.008 for trend).

CONCLUSION

Our data indicate an association between chronic anemic hypoxia and increased PAP in SLE patients and suggest that increased IL-6 might participate in this process.

An integrated extrapolation of long-term outcomes in systemic lupus erythematosus: analysis and simulation of the Hopkins lupus cohort

OBJECTIVE

The aim of this study was to develop an SLE disease model that simulates long-term outcomes of SLE to estimate the long-term effectiveness and cost-effectiveness of SLE treatments.

METHODS

Longitudinal data from 1354 patients from the Hopkins Lupus Cohort were included in the analysis. Statistical models were created to estimate disease activity [Safety of Estrogen in Lupus Erythematosus National Assessment (SELENA) SLEDAI scale] and prednisone dose over time using linear regression. Survival models for organ damage and mortality were created. The models were combined in a predictive simulation of SLE organ damage and mortality. Predictions were assessed against the Hopkins Lupus Cohort data.

RESULTS

The analyses found that change in the annual average SLEDAI score was associated with the previous annual average SLEDAI score, renal involvement, age, male gender, African American ethnicity, anaemia, haematological involvement, increased DNA binding and low complement. The annual average prednisone dose increased for every unit increase in annual average SLEDAI. Organ damage and mortality modelling demonstrated that adjusted mean SLEDAI and binary SLEDAI organ involvement indicators predicted mortality, cardiovascular, renal, neuropsychiatric, pulmonary, gastrointestinal, ocular and skin damage. The cumulative average prednisone dose was associated with risk of cardiovascular, ocular, musculoskeletal, neuropsychiatric and gastrointestinal damage, gonadal failure and diabetes mellitus. The simulation reproduced mean SLEDAI and organ damage scores from the Hopkins Lupus Cohort.

CONCLUSION

Longitudinal modelling of an SLE cohort confirmed relationships between risk factors and long-term outcomes in SLE. The models serve to estimate the probability of SLE outcomes over time and can be used to estimate the effectiveness and cost-effectiveness of new treatments.

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.

Factors associated with arterial vascular events in PROFILE: a Multiethnic Lupus Cohort

The objective of this study was to determine the factors associated with the occurrence of arterial vascular events in a multiethnic systemic lupus erythematosus (SLE) cohort. The PROFILE cohort, comprised SLE patients (n = 1333) of defined ethnicity from five different US institutions, was studied to determine demographic, clinical and biological variables associated with vascular events. An arterial vascular event (first episode) was either a myocardial infarction, angina pectoris and/or a vascular procedure for myocardial infarction, stroke, claudication and/or evidence of gangrene. Patient characteristics were analyzed by univariable and multivariable Cox proportional hazards regression analyses. One-hundred twenty-three (9.8%) patients had at least one incident arterial event. Age at cohort enrollment (HR = 1.04, 95% CI 1.03-1.06), smoking (HR = 2.20, 95% CI 1.40-3.46) and the CRP2* C alleles (HR = 1.91, 95% CI 1.04-3.49) were associated with a shorter time-to-the occurrence of arterial vascular events. Some clinical manifestations of disease activity were associated with a shorter time-to-occurrence [psychosis (HR = 2.21, 95% CI 1.10-4.44), seizures (HR = 1.85, 95% CI 1.00-3.24) and anaemia (HR = 1.83, 95% CI 1.02-3.31)], but others were not [arthritis (HR = 0.32, 95% CI 0.18-0.58)]. In conclusion, older patients, especially in the context of a predisposing environmental factor (smoking) and severe clinical manifestations, are at higher risk of having arterial vascular events. The genetic contribution of the variation at the CRP locus was not obscured by demographic or clinical variables. Awareness of these factors should lead to more effective management strategies of patients at risk for arterial vascular events.

Time to neuropsychiatric damage occurrence in LUMINA (LXVI): a multi-ethnic lupus cohort

The aims of this study were to examine the predictors of time to neuropsychiatric (NP) damage and its impact on mortality in 632 systemic lupus erythematosus African-American, Hispanic and Caucasian LUpus in MInorities: NAture versus Nurture (LUMINA) patients, age >or= 16 years and disease duration <or=5 years at baseline (T0). Time-to-NP damage and its impact on mortality were examined by Cox proportional hazards regressions. A total of 185 (29.3%) patients developed NP damage over a mean (SD) disease duration of 5.6 (3.7) years. After adjusting for NP manifestations present, older age [Hazard ratio (HR) = 1.02; 95% Confidence interval (CI) 1.00-1.04], Caucasian ethnicity (HR = 1.87; 95% CI, 1.22-2.87), disease activity over the disease course (HR = 1.16; 95% CI, 1.12-1.21), diabetes (HR = 3.47; 95% CI, 1.44-8.38) and abnormal illness-related behaviours (HR = 1.05; 95% CI, 1.02-1.08) were associated with a shorter time-to-NP damage. Photosensitivity (HR = 0.65; 95% CI, 0.44-0.95), anaemia (HR = 0.56; 95% CI, 0.31-0.98), Raynaud's phenomenon (HR = 0.49; 95% CI, 0.34-0.72), a medium dose of prednisone (HR = 0.56; 95% CI, 0.35-0.92) and hydroxychloroquine use (HR = 0.58; 95% CI, 0.36-0.93) were associated with a longer time. NP damage did not contribute to mortality. Older age, Caucasian ethnicity, disease activity and abnormal illness-related behaviours are associated with a shorter time-to-NP damage; hydroxychloroquine and a medium dose of prednisone with a longer time.

Study on clinical features and complications with systemic lupus erythematosus (SLE) activity in Chinese Han population

Systemic lupus erythematosus (SLE) is a complex autoimmune disease affecting multiple organs/systems with variable activities. We performed a retrospective study to investigate the relationship of clinical characteristics and complications with SLE activity in Chinese Han population. A cohort of 1,490 SLE inpatients was evaluated for disease activity using the systemic lupus erythematosus disease activity index (SLEDAI). Chi-square test or Fisher's exact test was used to compare differences of clinical and laboratory features between active and inactive SLE patients. Logistic regression was chosen to explore the pattern of risk factors for disease activity. We found that neuropsychiatric involvement, nephritis, arthralgia, anti-dsDNA, serositis, hypocomplementemia, oral ulcerations, erythrocyte sedimentation rate, low C3, hematological abnormalities, and systolic pressure (1.010 < odds ratio < 10.568, 1.002 < 95% confidence interval < 31.599, 0.000 < P < 0.026) were major factors associated with disease activity, but not headaches, anti-ribonucleoprotein or anti-Sm, C-reactive protein, and anemia (P > 0.05, respectively). The involvements of urinary system, respiratory system, and central nervous system were significantly more frequent in active SLE than inactive SLE (0.000 < P < 0.014), except for alimentary system (P = 0.399). Our study has comprehensively evaluated the relationship of clinical characteristics and organs/systems involvement of SLE with SLEDAI in Chinese Han population and presented a compendium of factors affecting SLE, which should be useful for better evaluating disease activity and predicting organs/systems damage in SLE for clinical assessments and managements.

Haemolytic anaemia in a multi-ethnic cohort of lupus patients: a clinical and serological perspective

Systemic lupus erythematosus is a chronic autoimmune disease that can be associated with a variety of haematological manifestations. We identified 76 patients with haemolytic anaemia in a cohort of 1251 unrelated female lupus patients enrolled in our studies. The presence of the various American College of Rheumatology clinical criteria for lupus and serological specificities were determined in lupus patients with haemolytic anaemia and compared with a group of race-matched control lupus patients without haemolytic anaemia. Clinical data were obtained from medical records, and serological specificities were determined in our clinical immunology laboratory at OMRF. The presence of haemolytic anaemia in lupus patients was associated with a higher frequency of proteinuria (OR = 2.70, P = 0.000031), urinary cellular casts (OR = 2.83, P = 0.000062), seizures (OR = 2.96, P = 0.00024), pericarditis (OR = 2.21, P = 0.0019), pleuritis (OR = 1.72, P = 0.028) and lymphopenia (OR = 1.79, P = 0.015). These findings were independent of the presence of thrombocytopenia, which was approximately five times more common in lupus patients with haemolytic anaemia. Lupus patients with haemolytic anaemia were about 8 years younger than lupus patients without haemolytic anaemia at the time of disease onset (P = 0.000001). In the absence of thrombocytopenia, lupus patients with haemolytic anaemia were approximately two times more likely to have anti-dsDNA antibodies (P = 0.024). The presence of haemolytic anaemia is associated with a subset of lupus characterized by a younger age of disease onset, and a more severe disease with a higher likelihood of renal involvement, seizures, serositis and other cytopenias.