Beyond ISN/RPS lupus nephritis classification: adding chronicity index to clinical variables predicts kidney survival

Background. A renewed interest for activity and chronicity indices as predictors of lupus nephritis (LN) outcome has emerged. Revised National Institutes of Health (NIH) activity and chronicity indices have been proposed to classify LN lesions but should be validated by future studies. Aims of this study: i) to detect the histological features associated with the development of Kidney Function Impairment (KFI); ii) to identify the best clinical-histological model to predict KFI at time of kidney biopsy. Methods. LN patients with kidney biopsy containing >10 glomeruli per specimen were admitted to the study. Univariate and multivariate logistic regression and Cox proportional hazards model were used to investigate whether activity and chronicity indices could predict KFI development. Results. Among 203 LN participants followed for 14 years, correlations were found between activity index and its components and clinical-laboratory signs of active LN at baseline. Chronicity index was correlated with serum creatinine. Thus, serum creatinine was significantly and directly correlated with both activity and chronicity indexes. At multivariate analysis glomerular sclerosis (OR:3.0478, CI:1.173-7.91, P=0.022) and fibrous crescents (OR:6.8352, CI:3.218-14.519, P<0.001) associated with either moderate/severe tubular atrophy (OR:3.1697, CI:1.042-9.643, P=0.0421), or with interstitial fibrosis (OR:2.361, CI:1.047-5.322, P=0.0383) predicted KFI. Considering both clinical and histological features, serum creatinine (OR:1.677; 1.311-2.145; P<0.001), arterial hypertension (OR:4.641, CI: 1.902-11.324, P<0.001), glomerular sclerosis (OR:2.123, CI:1.001-4.503, P=0.049), and fibrous crescents (OR:5.182, CI: 2.433-11.037, P<0.001) independently predicted KFI. Older age (P<0.001) and longer delay between clinical onset of LN and kidney biopsy (P<0.001) were significantly correlated with baseline chronicity index. Conclusions. Chronicity index and its components, but not activity index, were significantly associated with an impairment of kidney function. The Cox model showed that serum creatinine, arterial hypertension, chronic glomerular lesions and delay in kidney biopsy predicted KFI. These data reinforce the importance of timely kidney biopsy in LN.

The relationship between the modified National Institute of Health activity and chronicity scoring system, and the long-term prognosis for lupus nephritis: A retrospective single-center study

Background The revision of International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification guidelines for lupus nephritis (LN) was suggested by a working group, who recommended a modified National Institute of Health (NIH) activity and chronicity scoring system to evaluate active and chronic LN lesions. However, whether this approach was useful for estimating long-term prognosis for LN patients is unclear. Methods We conducted a retrospective cohort study in Japanese subjects with biopsy-proven LN, between 1977 and 2018. Pathologic lesions were evaluated based on ISN/RPS 2003 classifications and the modified NIH scoring system. Patients were grouped by activity index (low, 0–5; moderate, 6–11; high, 12–24), and chronicity index (low, 0–2; moderate, 3–5; high, 6–12). The primary outcome was a composite of end-stage kidney disease (ESKD) or all-cause death, and the secondary outcome was ESKD alone. Results Sixty-six subjects with a median age of 31 years were included. During median follow-up (11.5 years), 15 patients reached the primary outcome: 10 had ESKD, four had died, and one had ESKD and died. Kaplan–Meier analysis showed that the cumulative primary outcome incidence increased with a higher chronicity index (log-rank trend p < 0.001). From multivariable survival analysis, moderate (hazard ratio [HR] 6.17, 95% confidence interval [CI] 1.14 to 33.20; p = 0.034) and high chronicity indices (HR 20.20, 95% CI 1.13 to 359.82; p = 0.041) were risk factors for the primary outcome. Conclusion Moderate and high chronicity indices were associated with an increased ESKD risk for LN.

Hsa_circ_0123190 acts as a competitive endogenous RNA to regulate APLNR expression by sponging hsa-miR-483-3p in lupus nephritis

Background Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus (SLE). Circular RNAs (circRNAs) can act as competitive endogenous RNAs (ceRNAs) to regulate gene transcription, which is involved in mechanism of many diseases. However, the role of circRNA in lupus nephritis has been rarely reported. In this study, we aim to investigate the clinical value of circRNAs and explore the mechanism of circRNA involvement in the pathogenesis of LN. Methods Renal tissues from three untreated LN patients and three normal controls (NCs) were used to identify differently expressed circRNAs by next-generation sequencing (NGS). Validated assays were used by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The interactions between circRNA and miRNA, or miRNA and mRNA were further determined by luciferase reporter assay. The extent of renal fibrosis between the two groups was assessed by Masson-trichome staining and immunohistochemistry (IHC) staining. Results 159 circRNAs were significantly dysregulated in LN patients compared with NCs. The expression of hsa_circ_0123190 was significantly decreased in the renal tissues of patients with LN (P = 0.014). Bio-informatics analysis and luciferase reporter assay illustrated that hsa_circ_0123190 can act as a sponge for hsa-miR-483-3p, which was also validated to interact with APLNR. APLNR mRNA expression was related with chronicity index (CI) of LN (P = 0.033, R2 = 0.452). Moreover, the fibrotic-related protein, transforming growth factor-β1 (TGF-β1), which was regulated by APLNR, was more pronounced in the LN group (P = 0.018). Conclusion Hsa_circ_0123190 may function as a ceRNA to regulate APLNR expression by sponging hsa-miR-483-3p in LN.

Interaction Toxicity Study between P-glycoprotein Inhibitor (Captopril) and Inducer (Spironolactone) with Their Substrate (Lovastatin) in Male Rats

An interaction toxicity study was performed to evaluate and compare the effect of P-glycoprotein (P-gp) inhibitor (captopril) and inducer (spironolactone) on their common substrate (lovastatin) that were done by comparing LD50 of the acute study with their chronic form then with those combined therapeutic doses administered for 90 days. Therefore, isobolographic analysis and chronicity index were used as the parameters for this study. Forty rats were allocated into five groups according to the used treatment into: captopril, spironolactone, lovastatin, captopril + lovastatin and spironolactone + lovastatin using up and down method to determine their acute exposure LD50 while ninety rats were used to perform the chronic stage of the study divided equally into six groups according to daily dosing regimen as following G1- control group administered distilled water orally; G2 administered captopril 0.7 mg/kg BW orally; G3-administered spironolactone 1.4 mg/kg BW orally; G4- administered lovastatin 0.57 mg/kg BW orally; G5-administered spironolactone1.4 mg/kg BW orally and lovastatin 0.57 mg/kg BW, G6- administered captopril 0.7 mg/kg BW and lovastatin 0.57 mg/kg BW orally. The results of isobolographic analysis showed that the sort of interaction between P-gp inhibitor (captopril) and lovastatin alone and as combined administration showed to be antagonistic after acute administration while it was synergistic after chronic administration; for P-gp inducer, spironolactone and lovastatin were additive after acute administration and antagonistic after chronic administration. Chronicity index results showed that both captopril and lovastatin accumulated after administered each alone and showed more accumulation after their combined administration while the chronicity index for P-gp inducer (spironolactone) and lovastatin showed less total concentration in the body burden after their combined administration than alone one. In conclusion, it seems that P-gp inhibitor (captopril) causes accumulation of itself and substrate (lovastatin), while P-gp inducer (spironolactone) causes reduction on the body burden of itself as well as lovastatin possibly due to their effects on the kinetics of the body and this may affect the efficacy and safety of drugs.

Hsa_circ_0123190 acts as a competitive endogenous RNA to regulate APLNR expression by sponging hsa-miR-483-3p in lupus nephritis

Background: Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus (SLE). Circular RNAs(circRNAs) can act as competitive endogenous RNAs (ceRNAs) to regulate gene transcription, which is involved in mechanism of many diseases. However, the role of circRNA in lupus nephritis has been rarely reported. In this study, we aim to investigate the clinical value of circRNAs and explore the mechanism of circRNA involvement in the pathogenesis of LN. Methods: Renal tissues from three untreated LN patients and three normal controls (NCs) were used to identify differently expressed circRNAs by next-generation sequencing (NGS). Validated assays were used by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The interactions between circRNA and miRNA, or miRNA and mRNA were further determined by luciferase reporter assay. The extent of renal fibrosis between the two groups was assessed by Masson-trichome staining and immunohistochemistry (IHC) staining. Results: 159 circRNAs were significantly dysregulated in LN patients compared with NCs. The expression of hsa_circ_0123190 was significantly decreased in renal tissues of patients with LN (P =0.014). Bio-informatic analysis and luciferase reporter assay illustrated that hsa_circ_0123190 can act as a sponge for hsa-miR-483-3p, which was also validated to interact with APLNR. APLNR mRNA expression was related with chronicity index (CI) of LN (P =0.033, R 2 =0.452). Moreover, the fibrotic-related protein, transforming growth factor-β1 (TGF-β1), which was regulated by APLNR, was more pronounced in the LN group (P =0.018). Conclusion: Hsa_circ_0123190 may function as a ceRNA to regulate APLNR expression by sponging hsa-miR-483-3p in LN.

Comparison of the 2018 and 2003 International Society of Nephrology/Renal Pathology Society classification in terms of renal prognosis in patients of lupus nephritis: a retrospective cohort study

Background Although the 2018 revised International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification was proposed recently, until now, no reports have been made comparing the association of renal prognosis between the 2018 revised ISN/RPS classification and the 2003 ISN/RPS classification. The present study aimed to assess the usefulness, especially of activity and chronicity assessment, of the 2018 revised ISN/RPS classification for lupus nephritis (LN) in terms of renal prognosis compared to the classification in 2003. Methods We retrospectively collected medical records of 170 LN patients from the database of renal biopsy at Fujita Health University from January 2003 to April 2019. Each renal biopsy specimen was reevaluated according to both the 2003 ISN/RPS classification and the 2018 revised ISN/RPS classification. Renal endpoint was defined as a 30% decline of estimated glomerular filtration rate (eGFR). Results A total of 129 patients were class III/IV±V (class III, 44 patients; class IV, 35 patients; class III/IV+V, 50 patients). The mean age was 42 years, 88% were female, and the median observation period was 50.5 months. Renal prognosis was significantly different among the classes and significantly poor in the patients with higher modified National Institute of Health (mNIH) chronicity index (C index, ≥ 4) by a log-rank test (p = 0.05 and p = 0.02, respectively). By Cox proportional hazard models, only the C index was significantly associated with renal outcome (hazard ratio 1.32, 95% CI 1.11–1.56, p ≤ 0.01), while the classes, the 2003 activity and chronicity subdivision, and the mNIH activity index had no significant association with renal outcome. Each component of the C index was significantly associated with renal outcome in different models. Conclusion This study demonstrates that the 2018 revised ISN/RPS classification was more useful in terms of association with renal prognosis compared to the 2003 ISN/RPS classification.

Value of monitoring urine ammonia at time of biopsy in patients with lupus nephritis

Objective Although lupus nephritis (LN) is mostly characterized by glomerular involvement, tubular injury is indispensable in its pathogenesis and progression. The purpose of this study is to examine associations between urinary acidification function and clinical and pathological features in LN. Methods A total of 103 patients with renal biopsy-proven LN were included, and clinical parameters and laboratory data were obtained from the medical records. Plasma samples, 24-h urine samples and the urinary acidification function, including urine pH, titratable acid, and ammonia, were collected within 3 days before the day of renal biopsy. The correlations between defects of acid excretion and clinical and pathological features were then assessed. Logistic regression analysis was used to assess factors associated with the presence of nephrotic range proteinuria. Results The urine ammonia level was inversely correlated with SLEDAI-2 K scores, rSLEDAI scores, serum creatinine levels and proteinuria, while it was positively correlated with eGFR. And urine titratable acid was only inversely correlated with rSLEDAI scores and proteinuria. Moreover, urine ammonia had significant negative correlations with AI scores, interstitial inflammatory cell infiltration, CI scores, glomerular sclerosis, fibrous crescents, tubular atrophy and interstitial fibrosis. And urine titratable acid was mainly inversely correlated with CI scores. Furthermore, univariate logistic analyses identified that both urine titratable acid and ammonia were correlated with the presence of nephrotic range proteinuria. After the adjustment for chronicity index and eGFR in a multivariate logistic analysis, only urine titratable acid was still identified as an independent risk factor for the occurrence of nephrotic range proteinuria. Conclusions Urine ammonia was associated with clinical and pathological features of chronicity and tubulointerstitial disease activity among patients with lupus nephritis. Furthermore, the strong association between urinary protein and titratable acid excretion at the time of kidney biopsy is significant even after adjusting for the chronicity index and eGFR at biopsy.

Comparison of 2018 and 2003 International Society of Nephrology/Renal Pathology Society classification in terms of renal prognosis in patients of lupus nephritis: a retrospective cohort study.

Background: Although 2018 revised ISN/RPS classification was proposed recently, until now, no reports have been made comparing the association of renal prognosis between 2018 revised ISN/RPS classification and 2003 ISN/RPS classification. The present study aimed to assess the usefulness, especially of activity and chronicity assessment, of the 2018 revised International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification for lupus nephritis (LN) in terms of renal prognosis compared to the classification in 2003.Methods: We retrospectively collected medical records of 170 LN patients from the database of renal biopsy in Fujita Health University from January 2003 to April 2019. Each renal biopsy specimen was reevaluated according to both the 2003 ISN/RPS classification and the 2018 revised ISN/RPS classification. Renal endpoint was defined as 30% decline of estimated glomerular filtration rate (eGFR). Results: A total 129 patients were class III/IV±V (class III, 44 patients; class IV, 35 patients; class III/IV+V, 50 patients). Mean age was 42 years, 88% were female, and median observation period was 50.5 months. Renal prognosis was significantly different among the classes, and significantly poor in the patients with higher modified National Institute of Health (mNIH) Chronicity index (C index, ≥4) by a log-rank test (p=0.05, p=0.02 respectively). By Cox proportional hazard models, only C index was significantly associated with renal outcome (Hazard Ratio; 1.32, 95% CI; 1.11-1.56, p≤0.01), while the classes, the 2003 activity and chronicity subdivision, and mNIH activity index had no significant association with renal outcome. Each component of C index was significantly associated with renal outcome in different models. Conclusion: This study demonstrates that the 2018 revised ISN/RPS classification was more useful in terms of association with renal prognosis compared to the 2003 ISN/RPS classification

Lupus nephritis: correlation of immunohistochemical expression of C4d, CD163-positive M2c-like macrophages and Foxp3-expressing regulatory T cells with disease activity and chronicity

Background C4d, which is a serum complement cleavage product of the activated complement component C4, was found to be an accurate indicator of lupus activity compared to complement levels. Recently, macrophages have been considered to be pivotal members in the pathogenesis of lupus nephritis (LN). M2c-like macrophages have anti-inflammatory functions and promote fibrosis. Multiple studies have detected that LN is associated with an imbalance between the regulatory T cell (Treg) population and the inflammatory T helper subtypes. Methods We evaluated and scored the immunohistochemical expression of C4d, CD163-positive M2C-macrophages and Foxp3-expressing Tregs in 53 renal biopsies of LN. Their expression was scored and correlated with clinical and histological disease activity and chronicity. Results Class IV was the most prevalent class (50.9%), followed by class III (17%). PTC-C4d intensity score, CD163% of positive M2c macrophages and FOXP3% of positive Tregs were significantly correlated with chronicity index ( rs = 0.292, p = 0.034; rs = 0.407, p = 0.003; and rs = 0.296, p = 0.031, respectively). Also, FOXP3% of positive Tregs was significantly correlated with LN class ( rs = 0.31, p = 0.024). Conclusion C4d-PTC, CD163-positive M2c macrophages and FOXP3-positive Tregs are markers that significantly correlated with chronicity in LN. Further studies are needed to evaluate their prognostic value.

Lack of EULAR/ERA-EDTA response at 1 year predicts poor long-term renal outcome in patients with lupus nephritis

ObjectivesShort-term predictive endpoints of chronic kidney disease (CKD) are needed in lupus nephritis (LN). We tested response to therapy at 1 year.MethodsWe considered patients with LN who underwent renal biopsy followed by induction therapy between January 1970 and December 2016. LN was assessed using the International Society of Nephrology/Renal Pathology Society (2003) criteria and the National Institute of Health (NIH) activity and chronicity index. The renal outcome was CKD. Response was defined according to EULAR/European League Against Rheumatism/European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations: complete: proteinuria <0.5 g/24 hours, (near) normal estimated glomerular filtration rate (eGFR); partial: ≥50% proteinuria reduction to subnephrotic levels, (near) normal eGFR; and no response: all the other cases. Logistic regression analysis was employed for 12-month response and Cox regression for CKD prediction.ResultsWe studied 381 patients (90.5% Caucasians). After 12-month therapy, 58%, 26% and 16% of patients achieved complete, partial and no response, respectively, according to EULAR/ERA-EDTA. During a median follow-up of 10.7 (IQR: 4.97–18.80) years, 53 patients developed CKD. At 15 years, CKD-free survival rate was 95.2%, 87.6% and 55.4% in patients with complete, partial and no response at 12 months, respectively (p<0.0001). CKD-free survival rates did not differ between complete and partial responders (p=0.067). Serum creatinine (HR: 1.485, 95% CI 1.276 to 1.625), eGFR (HR 0.967, 95% CI 0.957 to 0.977) and proteinuria at 12 months (HR 1.234, 95% CI 1.111 to 1.379) were associated with CKD, yet no reliable cut-offs were identified on the receiver operating characteristic curve. In multivariable analysis, no EULAR/ERA-EDTA response at 12 months (HR 5.165, 95% CI 2.770 to 7.628), low C4 (HR 1.053, 95% CI 1.019 to 1.089) and persistent arterial hypertension (HR 3.154, 95% CI 1.500 to 4.547) independently predicted CKD.ConclusionsLack of EULAR/ERA-EDTA response at 12 months predicts CKD.