Predictors of kidney disease in a cohort of pediatric patients with lupus

Albumin to globulin ratio (AGR) in systemic lupus erythematosus: correlation with disease activity

OBJECTIVE

To investigate the role of albumin-to-globulin ratio (AGR) in systemic lupus erythematosus (SLE) and its relationship with disease activity.

METHODS

This retrospective study consecutively selected patients with SLE and healthy controls. Patients were divided into three groups according to the SLE Disease Activity Index 2000 (SLEDAI-2K): group 1 (mild disease activity, SLEDAI-2K ≤ 6), group 2 (moderate disease activity, SLEDAI-2K 7-12) and group 3 (severe disease activity, SLEDAI-2K > 12). Predictors of SLE disease activity were analysed by ordinal logistical regression.

RESULTS

A total of 101 Chinese patients with SLE and 75 healthy Chinese controls were included. Patients with SLE had lower AGR values than healthy individuals, and group 3 patients with SLE displayed lower AGR values than those in group 1, but similar values to group 2. AGR was inversely correlated with SLEDAI-2K (r = -0.543). Ordinal logistic regression analysis showed that lower AGR (β = -1.319) and lower complement C4 (β = -1.073) were independent risk factors for SLE disease activity.

CONCLUSIONS

AGR was decreased in patients with SLE and may be utilized as a useful inflammatory biomarker for monitoring SLE disease activity.

Autoantibodies in lupus nephritis useful in distinguishing proliferative nephritis from membranous nephritis

OBJECTIVES

This study was conducted to determine autoantibodies associated with lupus nephritis (LN), especially those useful in diagnosing proliferative and membranous nephritis.

METHODS

A total of 106 patients with LN and 63 patients with systemic lupus erythematosus but no nephritis were enrolled; then, 55 patients were selected from the LN group and were divided into two groups: proliferative nephritis patients (n = 36) and membranous nephritis patients (n = 19). The autoantibody profiles of patients' sera were evaluated using the EUROLINE ANA Profile 3 (IgG) kit.

RESULTS

A higher positivity rate of anti-double-stranded DNA antibody and anti-histone antibody was seen in LN patients compared to nonrenal systemic lupus erythematosus patients. In comparing between proliferative and membranous nephritis, the positivity of anti-nucleosome antibody was higher in proliferative nephritis, although it was not statistically significant. However, anti-nucleosome antibody-positive patients with LN had a higher prevalence of haematuria and pyuria, which are strong indications of proliferative nephritis. Also, a significantly higher positivity rate of anti-RNP70 antibody was seen in membranous nephritis compared to proliferative nephritis.

CONCLUSIONS

Our results showed that anti-nucleosome and anti-RNP70 antibodies may be predictive nonhistological factors for discriminating between proliferative and membranous LN.

Glomerulonephritis

Glomerulonephritis (GN) encompasses several disorders that cause glomerular inflammation and injury through an interplay of immune-mediated mechanisms, host characteristics, and environmental triggers, such as infections. GN can manifest solely in the kidney or in the setting of a systemic illness, and presentation can range from chronic and relatively asymptomatic hematuria to fulminant renal failure. Classic acute GN is characterized by hematuria, edema, and hypertension, the latter 2 of which are the consequence of sodium and water retention in the setting of renal impairment. Although presenting signs and symptoms and a compatible clinical history can suggest GN, serologic and urinary testing can further refine the differential diagnosis, and renal biopsy can be used for definitive diagnosis. Treatment of GN can include supportive care, renin-angiotensin-aldosterone system blockade, immunomodulatory therapy, and renal transplant. Prognosis is largely dependent on the underlying cause of GN and can vary from a self-limited course to chronic kidney disease. This review focuses on lupus nephritis, IgA nephropathy, IgA vasculitis, and postinfectious GN.

Risk factors for subsequent lupus nephritis in patients with juvenile-onset systemic lupus erythematosus: a retrospective cohort study

BACKGROUND

Lupus nephritis (LN) is a crucial organ involvement in systemic lupus erythematosus (SLE). Patients with LN have higher morbidity and mortality rates than those without. Among all patients with LN, 20-40% had delayed onset, but the data for patients with juvenile-onset SLE (jSLE), who have a higher percentage of LN than patients with adult-onset SLE (aSLE), were limited. This study aimed to determine the risk factors for subsequent LN in patients with jSLE.

METHODS

A retrospective cohort study was conducted between 2008 and 2018 in a single tertiary medical centre. Patients with diagnosed jSLE were reviewed. We investigated those without LN at diagnosis and whether they developed LN afterward. The primary outcome was the development of subsequent LN. Clinical manifestations at diagnosis, serial laboratory data, and treatments were reviewed during follow-up periods.

RESULTS

Among the 48 patients with jSLE without initial LN, 20 developed subsequent LN later (Group 1), whereas 28 remained free of LN (Group 2). There was no difference in the percentage of initial manifestations except for more discoid rashes in Group 2 patients. In the Cox regression model, elevated average anti-double-stranded DNA (dsDNA) antibody, low average serum complements, and high average erythrocyte sedimentation rate (ESR) levels during follow-up were predictors of subsequent LN. After adjusting for these factors in multivariable analyses, only high average anti-dsDNA antibody and high average ESR levels remained predictive of subsequent LN. For every 100 IU/ml increase in anti-dsDNA antibody, the risk for subsequent LN in jSLE increases by 1.29 times (hazard ratio = 1.29, 95% confidence interval 1.055-1.573).

CONCLUSION

Persistently high anti-dsDNA antibody and ESR levels during the follow-up period were risk factors for subsequent LN in patients with jSLE.

A Preliminary Predictive Model for Proliferative Lupus Nephritis in Juvenile Systemic Lupus Erythematosus

Proliferative lupus nephritis, which is diagnosed by renal biopsy, has significant impact on the treatment choices and long-term prognosis of juvenile SLE (jSLE). Renal biopsies are however not always possible or available, thus leading to an ongoing search for alternative biomarkers. This study aimed to develop a clinical predictive machine learning model using routine standard parameters as an alternative tool to evaluate the probability of proliferative lupus nephritis (ISN/RPS Class III or IV). Data were collected retrospectively from jSLE patients seen at Selayang Hospital from 2004 to 2021. A total of 22 variables including demographic, clinical and laboratory features were analyzed. A recursive feature elimination technique was used to identify factors to predict pediatric proliferative lupus nephritis. Various models were then used to build predictive machine learning models and assessed for sensitivity, specificity and accuracy. There were 194 jSLE patients (165 females), of which 111 had lupus nephritis (54 proliferative pattern). A combination of 11 variables consisting of gender, ethnicity, fever, nephrotic state, hypertension, urine red blood cells (RBC), C3, C4, duration of illness, serum albumin, and proteinuria demonstrated the highest accuracy of 79.4% in predicting proliferative lupus nephritis. A decision-tree model performed the best with an AROC of 69.9%, accuracy of 73.85%, sensitivity of 78.72% and specificity of 61.11%. A potential clinically useful predictive model using a combination of 11 non-invasive variables to collectively predict pediatric proliferative lupus nephritis in daily practice was developed.

Predictive Factors for Renal Response in Lupus Nephritis: A Single-center Prospective Cohort Study

Objective

To identify the predictive factors for renal response in patients with lupus nephritis (LN).

Methods

Patients and data were extracted from a prospective systemic lupus erythematosus cohort in Korea, in which clinical data were collected at 0, 3, 6, and 12 months after induction therapy. Treatment response of LN were evaluated as a complete response (CR), partial response (PR), or non-response (NR) at 3, 6, and 12 months, respectively. Predictive factors for CR at 6 months were evaluated using multivariable Poisson regression analysis.

Results

A total of 75 patients with LN who underwent biopsy was enrolled. The mean age at diagnosis of LN was 28.9±9.7 years, and 68 (90.7%) were female. The frequencies of classes III, IV, III+V, IV+V, and V were 20.0%, 44.0%, 16.0%, 12.0%, and 8.0%, respectively. Compared to relapsed LN, new-onset LN showed a lower percentage of glomerulosclerosis (45.5% vs. 76.2%, p=0.013). The overall proportions of CR, PR, and NR at 6 and 12 months were 52.0%, 26.7%, 21.3% and 50.7%, 24.0%, 25.3%, respectively. In multivariate analysis, age at enrollment (odds ratio [OR]=1.02, p=0.022), relapsed LN (OR=0.71, p=0.037), anti-Ro antibody (OR=0.67, p=0.014), and class III LN (OR=1.48, p=0.001) were associated with CR at 6 months.

Conclusion

In our prospective cohort, class III LN was a good predictive factor for CR at 6 months in patients with LN, whereas younger age, relapsed LN, and anti-Ro antibody were poor predictive factors.

Clinical measurement of lupus nephritis activity is inferior to biomarker-based activity assessment using the renal activity index for lupus nephritis in childhood-onset systemic lupus erythematosus

OBJECTIVES

The renal activity index for lupus (RAIL) measures lupus nephritis (LN) activity considering urine levels of 6 biomarkers (neutrophil gelatinase-associated lipocalin, monocyte chemoattractant protein-1, kidney injury molecule-1, adiponectin, haemopexin, ceruloplasmin). We aimed to compare the accuracy of the RAIL and the renal domain-score of the SLE disease activity index (rSLEDAI) in detecting LN activity.

METHODS

Random urine samples of patients with childhood-onset SLE with and without LN were assayed and scores of the RAIL, and RAIL standardised for urine creatinine (RAIL-Cr) were calculated. Clinical LN activity was measured by the rSLEDAI, and histological activity of LN was categorised as inactive/low-moderate/high for National Institute of Health-activity index scores of <2/2-10/>10, respectively.

RESULTS

115 patients were included in the analysis (47 patients without and 68 with LN). RAIL, RAIL-Cr and rSLEDAI scores at the time (±3 months) of kidney biopsy were available for 32 patients. Median rSLEDAI, RAIL and RAIL-Cr values were 4, -0.04, 0.02 for inactive LN, 12, 0.7 and 0.9 for low-moderate LN activity and 12, 2 and 1.8 for high LN activity, respectively. The area under the receiver operating characteristic curve (AUC) to capture high LN activity was the lowest for the rSLEDAI (AUC=0.62), followed by the RAIL-Cr (AUC=0.73) and RAIL (AUC=0.79). Notably, when testing urine samples collected during routine clinic visits remote (>3 months) from a kidney biopsy, 50% patients with rSLEDAI scores of 0 had RAIL scores reflecting low-moderate LN activity.

CONCLUSION

Monitoring of renal inflammation in children and adolescents with SLE can be improved by the measurement of urine biomarkers. The RAIL may constitute important auxiliary tool for the surveillance of LN in a clinical setting and assist with the decision to obtain a kidney biopsy.

The Differential Diagnosis of Sterile Pyuria in Pediatric Patients: A Review

Sterile pyuria is a common finding in pediatric patients. Literature describing the diagnoses as well as clinical characteristics of children with sterile pyuria is lacking. This review was performed to establish an evidence-based approach to the differential diagnosis by way of an extensive literature search. The definition of pyuria is inconsistent. The various causes of pediatric sterile pyuria identified were classified as either Infectious or Non-Infectious. Sub-categories of Infectious causes include: Viral Infection, Bacterial Infection, Other Infections (tuberculosis, fungal, parasitic), Sexually Transmitted Infections, Recent Antibiotic Therapy. Non-Infectious causes include: Systemic Disease, Renal Disease, Drug Related, Inflammation adjacent to Genitourinary Tract. Clinicians that encounter pediatric patients with sterile pyuria and persistent symptoms should consider the substantial differential diagnosis described in this study.

Albumin-to-globulin ratio (AGR) as a potential marker of predicting lupus nephritis in Chinese patients with systemic lupus erythematosus

OBJECTIVES

To evaluate a potential role of albumin-to-globulin ratio (AGR) in the development of lupus nephritis (LN) and determine the potential to use AGR as a marker for future LN in systemic lupus erythematosus (SLE) patients.

METHODS

194 newly diagnosed SLE patients without renal impairment were followed. The clinical data were collected and analyzed at the time of initial diagnosis of SLE and the end of follow-up. We compared baseline characteristics between those who did or did not develop LN on follow-up. Univariate and multivariate Cox hazard analysis were used to identify predictors of lupus nephritis.

RESULTS

Among the 194 newly diagnosed SLE patients without renal impairment, 26 (13.40%) patients were diagnosed with LN during a median follow-up of 53.87 months. On univariate Cox analysis, patients with the history of alopecia, higher SBP, lower AGR, lower CRP, lower C3, lower C4, higher anti-dsDNA Ab, presence of ANA homogeneous patterns or higher SLEDAI had an increased probability of developing LN. In a multivariate model, the history of alopecia (adjust hazard ratio, aHR = 3.614, 95%CI 1.365-9.571 P = 0.010), lower AGR (aHR = 6.968, 95%CI 1.873-25.919, P = 0.004), lower CRP (aHR = 4.230, 95%CI 1.591-11.247, P = 0.004) and higher level of anti-dsDNA (aHR = 2.675, 95%CI 1.008-7.093, P = 0.048) were independently associated with an increased risk of developing LN after adjusting for covariates.

CONCLUSION

Our findings indicated that SLE patients with low AGR, low CRP, high anti-dsDNA and the history of alopecia were more likely to develop LN in the course of SLE. AGR shown the greatest hazard for developing LN among them, it may be a strong predictor.

Non-histologic factors discriminating proliferative lupus nephritis from membranous lupus nephritis

BACKGROUND

To investigate non-histologic factors that can discriminate proliferative lupus nephritis (LN) from membranous LN in patients with systemic lupus erythematosus with renal manifestations.

METHODS

Patients with biopsy-proven proliferative LN (class III ± V and class IV ± V) and membranous LN (class V) were included. Non-histologic factors were compared between the two groups. A logistic regression analysis was performed to identify the factors associated with proliferative LN. To assess the accuracy of these factors in discriminating between proliferative LN and membranous LN, we performed a receiver-operating characteristic analysis.

RESULTS

Of the total 168 patients with biopsy-proven LN, 150 patients (89.3%) had proliferative LN, and 18 patients (10.7%) had membranous LN. In the multivariable logistic regression analysis, positive anti-double-stranded DNA (anti-dsDNA) antibody (adjusted OR = 11.200, 95% CI = 2.202-56.957, p = 0.004) was associated with proliferative LN, while positive anti-U1RNP antibody (adjusted OR = 0.176, 95% CI = 0.040-0.769, p = 0.021) and higher glomerular filtration rate (GFR) (adjusted OR = 0.973, 95% CI = 0.951-0.994, p = 0.013) were inversely associated with proliferative LN. Among these covariates, the anti-dsDNA antibody (area under the curve = 0.806, 95% CI = 0.695-0.916) had the highest accuracy in discriminating between proliferative LN and membranous LN.

CONCLUSION

The positivity of anti-dsDNA antibody was associated with proliferative LN, while the positivity of anti-U1RNP antibody and GFR were inversely associated with proliferative LN. The anti-dsDNA antibody had a good accuracy in discriminating proliferative LN from membranous LN.

Plasma immunoglobulin binding protein 1 as a predictor of development of lupus nephritis

Objective

Urine levels of immunoglobulin binding protein 1 (IGBP1) are increased in patients with lupus nephritis (LN) compared with systemic lupus erythematosus (SLE) patients without nephritis. However, the clinical significance of IGBP1 level in plasma is unclear. We aimed to evaluate whether the plasma level of IGBP1 can predict future development of LN in SLE patients without nephritis.

Methods

Forty-three SLE patients without nephritis were followed for 5 years. Plasma IGBP1 levels were measured using ELISA, and clinical and laboratory data were obtained at study entry. Development of LN was confirmed by renal biopsy. Cox regression analysis was performed to identify factors associated with development of LN, and receiver operating characteristic curve analysis was used to determine the predictive value of each factor.

Results

Of the total 43 patients, eight (18.6%) developed LN during the follow-up period. Compared with patients who did not develop LN, those who developed LN had higher levels of plasma IGBP1 (6.3 ng/ml (range 4.3–9.6 ng/mL) vs. 13.3 ng/ml (range 7.2–31.3 ng/ml); p=0.023). In the Cox regression analysis, higher CRP (hazard ratio (HR)=1.325, 95% confidence interval (CI) 1.073–1.637, p=0.009), anti-dsDNA antibody (Ab; HR=1.066, 95% CI 1.012–1.124, p=0.017) and plasma IGBP1 (HR=1.091, 95% CI 1.034–1.152, p=0.002) were associated with future development of LN. Among these factors, anti-dsDNA Ab (area under the curve (AUC)=0.893) had the highest predictive value followed by plasma IGBP1 (AUC=0.761) and CRP (AUC=0.634). A combination of anti-dsDNA Ab and plasma IGBP1 as a composite predictor was highly specific (97%) for predicting the development of LN.

Conclusions

Plasma IGBP1 can be used complementarily with anti-dsDNA Ab for detecting SLE patients at a higher risk of developing LN.

Clinical predictors of active LN development in children – evidence from the UK JSLE Cohort Study

Background

Juvenile-onset systemic lupus erythematosus (JSLE) patients may develop lupus nephritis (LN) during their initial presentation, or later in their disease. This study aimed to assess whether clinical/demographic factors characterize patients with LN within the United Kingdom JSLE Cohort Study, and whether such factors predict subsequent LN development.

Methods

Univariate logistic regression modelling compared clinical/demographic factors in patients with and without LN at baseline. For those who subsequently developed LN, Cox proportional-hazard modelling was used to test the association between such factors and time to LN development. Covariates with p < 0.2 univariately were included within a multiple-regression model.

Results

A total of 121/331 (37%) patients presented with active LN at baseline, with first American College of Rheumatology (ACR) score ( p < 2.0 × 10–16), severe hypertension ( p = 0.0006), proteinuria ( p < 2.0 × 10–16), creatinine ( p = 1.0 × 10–16), erythrocyte sedimentation rate ( p = 1.0 × 10–16), neutrophils ( p < 2.0 × 10–16), complement 3 (C3) ( p = 4.0 × 10–16) and ethnicity ( p = 3.0 × 10–13) differing between those with and without LN. Of the 210 individuals without active LN at baseline, 13 patients had a single visit and were excluded from further analysis. Thirty-four of 197 (17%) developed LN after a median of 2.04 years (interquartile range, 0.8–3.7), with higher ACR scores ( p = 0.014 , hazard ratio (HR) = 1.45, 95% confidence interval (CI) = 1.08–1.95) and lower C3 levels ( p = 0.0082 , HR = 0.27, 95% CI = 0.10–0.68) demonstrated as predictors of subsequent LN.

Conclusions

Clinical and demographic factors can help to characterize patients at increased risk of LN.

Update on the pathogenesis and treatment of childhood-onset systemic lupus erythematosus

PURPOSE OF REVIEW

This article will provide an update of studies published in the last year regarding epidemiology, pathogenesis, major disease manifestations and outcomes, and therapies in childhood-onset systemic lupus erythematosus (cSLE).

RECENT FINDINGS

Recent studies on cSLE epidemiology supported previous findings that cSLE patients have more severe disease and tend to accumulate damage rapidly. Lupus nephritis remains frequent and is still a significant cause of morbidity and mortality. In the past year unfortunately there were no new reproducible, biomarker studies to help direct therapy of renal disease. However, some progress was made in neuropsychiatric disease assessment, with a new and promising automated test to screen for cognitive dysfunction reported. There were no prospective interventional treatment trials designed for patients with cSLE published in the last year, but some studies involving children are currently active and might improve the therapeutic options for patients with cSLE.

SUMMARY

There is a need to get a better understanding of pathogenesis and identify new biomarkers in cSLE to more accurately predict outcomes. New insights into characterization of different clinical manifestations may enable to optimize individual interventions and influence the prognosis.

Advances in the care of children with lupus nephritis

The care of children with lupus nephritis (LN) has changed dramatically over the past 50 y. The majority of patients with childhood-onset systemic lupus erythematosus (cSLE) develop LN. In the 1960's, prognosis in children was worse than in adults; therapies were limited and toxic. Nearly half of cases resulted in death within 2 y. Since this time, several diagnostic recommendations and disease-specific indices have been developed to assist physicians caring for patients with LN. Pediatric researchers are validating and adapting these indices and guidelines for the treatment of LN in cSLE. Classification systems, activity, and chronicity indices for kidney biopsy have been validated in pediatric cohorts in several countries. Implementation of contemporary immunosuppressive agents has reduced treatment toxicity and improved outcomes. Biomarkers sensitive to LN in children have been identified in the kidney, urine, and blood. Multi-institutional collaborative networks have formed to address the challenges of pediatric LN research. Considerable variation in evaluation and treatment has been addressed for proliferative forms of LN by development of consensus treatment practices. Patient survival at 5 y is now 95-97% and renal survival exceeds 90%. Moreover, international consensus exists for quality indicators for cSLE that consider the unique aspects of chronic disease in childhood.

Biomarkers for kidney involvement in pediatric lupus

Lupus nephritis (LN), the renal involvement in systemic lupus erythematosus, is currently diagnosed by histopathology obtained by percutaneous renal biopsy and is associated with increased morbidity and mortality in both adults and children. LN is more prevalent and severe in children, requiring aggressive and prolonged immunosuppression. The consequences of the diagnosis and its treatment have devastating long-term effects on the growth, well-being and quality of life of affected children. The paucity of reliable clinical indicators of the presence and severity of renal involvement have contributed to a halt in the reduction of progression to end-stage renal disease in recent years. Here, we discuss the recent development of biomarkers in the management of LN and their role as therapeutic targets.