Smoking is a risk factor for the progression of idiopathic membranous nephropathy

Prediction of immunotherapy response in idiopathic membranous nephropathy using deep learning-pathological and clinical factors

Background

Owing to individual heterogeneity, patients with idiopathic membranous nephropathy (IMN) exhibit varying sensitivities to immunotherapy. This study aimed to establish and validate a model incorporating pathological and clinical features using deep learning training to evaluate the response of patients with IMN to immunosuppressive therapy.

Methods

The 291 patients were randomly categorized into training (n = 219) and validation (n = 72) cohorts. Patch-level convolutional neural network training in a weakly supervised manner was utilized to analyze whole-slide histopathological features. We developed a machine-learning model to assess the predictive value of pathological signatures compared to clinical factors. The performance levels of the models were evaluated using the area under the receiver operating characteristic curve (AUC) on the training and validation tests, and the prediction accuracies of the models for immunotherapy response were compared.

Results

Multivariate analysis indicated that diabetes and smoking were independent risk factors affecting the response to immunotherapy in IMN patients. The model integrating pathologic features had a favorable predictive value for determining the response to immunotherapy in IMN patients, with AUCs of 0.85 and 0.77 when employed in the training and test cohorts, respectively. However, when incorporating clinical features into the model, the predictive efficacy diminishes, as evidenced by lower AUC values of 0.75 and 0.62 on the training and testing cohorts, respectively.

Conclusions

The model incorporating pathological signatures demonstrated a superior predictive ability for determining the response to immunosuppressive therapy in IMN patients compared to the integration of clinical factors.

Cumulative smoking dose is associated with subclinical renal injury: a pathological study in individuals without chronic kidney disease

BACKGROUND

Epidemiological studies have identified smoking as an independent risk factor for development of chronic kidney disease. However, the early renal pathological lesions have not been clearly elucidated.

METHODS

We investigated time-zero biopsy specimens from 547 living kidney donors and evaluated the relationships between smoking and renal histological changes, including arteriolar hyalinization, intimal thickening of small-medium arteries, global glomerulosclerosis, and interstitial fibrosis and tubular atrophy (IF/TA).

RESULTS

A total of 199 subjects (36.4%) had smoking history; 92 (16.8%) and 107 (19.6%) subjects had <20 pack-years and ≥20 pack-years of smoking, respectively. Cumulative smoking dose was significantly associated with prevalence of arteriolar hyalinization: the multivariable-adjusted odds ratio (OR) per 20 pack-year increase was 1.50 (95% confidence interval 1.15-1.97). The ORs for smokers with <20 pack-years and ≥20 pack-years versus never-smokers were 1.76 (1.01-3.09) and 2.56 (1.48-4.44), respectively. Smoking was also associated with prevalence of >10% global glomerulosclerosis: the OR per 20 pack-year increase was 1.24 (0.96-1.59). The ORs for smokers with <20 pack-years and ≥20 pack-years versus never-smokers were 1.50 (0.98-2.78) and 2.11 (1.18-3.79), respectively. The ORs for these pathological changes increased significantly depending on cumulative smoking dose. Intimal thickening of small-medium arteries and IF/TA were not associated with smoking status. The prevalence of arteriolar hyalinization remained higher in patients with ≥10 years since smoking cessation than in never-smokers [OR 2.23 (1.03-4.83)].

CONCLUSIONS

Subclinical pathological injury caused by smoking is potentially associated with renal arteriolar hyalinization and glomerular ischaemia.

CKD therapy to improve outcomes of immune-mediated glomerular diseases

The management of immunoglobulin A nephropathy, membranous nephropathy, lupus nephritis, anti-neutrophil cytoplasmic antibody-associated vasculitis, C3 glomerulonephritis, autoimmune podocytopathies and other immune-mediated glomerular disorders is focused on two major treatment goals, preventing overall mortality and the loss of kidney function. Since minimizing irreversible kidney damage best serves both goals, the management of immune-mediated kidney disorders must focus on the two central pathomechanisms of kidney function decline, i.e., controlling the underlying immune disease process (e.g. with immunotherapies) and controlling the non-immune mechanisms of chronic kidney disease (CKD) progression. Here we review the pathophysiology of these non-immune mechanisms of CKD progression and discuss non-drug and drug interventions to attenuate CKD progression in immune-mediated kidney disorders. Non-pharmacological interventions include reducing salt intake, normalizing body weight, avoiding superimposed kidney injuries, smoking cessation and regular physical activity. Approved drug interventions include inhibitors of the renin-angiotensin-aldosterone system and sodium-glucose cotransporter-2. Numerous additional drugs to improve CKD care are currently being tested in clinical trials. Here we discuss how and when to use these drugs in the different clinical scenarios of immune-mediated kidney diseases.

Two-sample mendelian randomization reveals a causal association between membranous nephropathy and lung cancer

A risk association between membranous nephropathy (MN) and lung cancer is reported, but traditional observational studies cannot provide strong evidence of its causality. This study aimed to assess genome-wide association studies data for a causal relationship between MN and lung cancer using a two-sample Mendelian randomization (MR) approach. Inverse-variance weighted, and MR Egger regression techniques were used to determine the association of genetic variants from cohorts of MN and lung cancer patients. Independent genetic variants with genome-wide significance (P < 5×10-8) were used to determine the direction of chance. Sensitivity analyses confirmed the accuracy of the results. The results suggest that MN is an exposure factor for lung cancer, validated using a second cohort of lung cancer patients (P < 0.001). There is insufficient evidence to suggest a causal relationship between lung cancer and MN; however, cigarette smoking may be a confounding factor for lung cancer due to MN. The findings provide causal evidence for the effect of MN on lung cancer risk and may be useful for patient management, especially in older patients with MN who should be systematically screened regularly.

Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease

Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.

Association between lifestyle, gender and risk for developing end-stage renal failure in IgA nephropathy: a case-control study within 10 years

Purpose: To investigate the potential association between lifestyles, including cigarette smoking, alcohol consumption, and physical exercise at the time of biopsy and the risk for developing end-stage renal failure (ESRF) among IgA nephropathy (IgAN) patients within 10 years.

Methods: A case–control study was carried out. Seventy-seven ESRF patients with the primary cause of IgAN were enrolled as cases. Seventy-seven IgAN patients who had not progressed to ESRF after being diagnosed for over 10 years served as controls. Smoking, alcohol consumption and physical exercise related data and baseline clinical features were collected from their medical records and confirmed by phone calls.

Results: The case group had higher proportions of males, smokers, drinkers, and physical inactivity individuals than the controls had. Alcohol drinking history (/1 year, OR 1.32, p < .05) is independently associated with an increased risk of ESRF, while physical exercise habits (OR 0.06, p < .05) associated with a decreased risk of ESRF in multivariate logistic analysis. Male gender, lower eGFR, and higher urinary protein at the time of biopsy were also independent risk factors. Moreover, male-non-exercise population seems to be more likely to progress to ESRF than others (male-exercise, female-exercise, and female-none-exercise populations).

Conclusion: Physical exercise should be encouraged in IgAN patients, especially in males, for a better renal outcome. Alcohol cessation might have a renal survival benefit in IgAN patients.

Urinary protein and renal prognosis in idiopathic membranous nephropathy: a multicenter retrospective cohort study in Japan

Background: Several studies have revealed a relationship between proteinuria and renal prognosis in idiopathic membranous nephropathy (IMN). The benefit of achieving subnephrotic proteinuria (<3.5 g/day), however, has not been well described.

Methods: This multicenter, retrospective cohort study included 171 patients with IMN from 10 nephrology centers in Japan. The relationship between urinary protein over time and a decrease of 30% in estimated glomerular filtration rate (eGFR) was assessed using time-dependent multivariate Cox regression models adjusted for clinically relevant factors.

Results: During the observation period (median, 37 months; interquartile range, 16–71 months), 37 (21.6%) patients developed a 30% decline in eGFR, and 2 (1.2%) progressed to end-stage renal disease. Time-dependent multivariate Cox regression models revealed that lower proteinuria over time were significantly associated with a lower risk for a decrease of 30% in eGFR (primary outcome), adjusted for clinically relevant factors. Complete remission (adjusted hazard ratio [HR], 0.005 [95%CI, 0.0–0.09], p < .001), incomplete remission with <1.0 g/day of urine protein (ICR I) (adjusted HR, 0.01 [95%CI, 0.001–0.20], p = .002), and 1.0 to 3.5 g/day (ICR II) (adjusted HR, 0.12 [95%CI, 0.02–0.64], p = .013) were significantly associated with avoiding a 30% decrease in eGFR, compared to that at no remission.

Conclusions: Attaining lower proteinuria predicts good renal survival in Japanese patients with IMN. This study quantifies the impact of proteinuria reduction in IMN and the clinical relevance of achieving subnephrotic proteinuria in IMN as a valuable prognostic indicator for both the clinician and patient.

Clinicopathological features of atypical membranous nephropathy with unknown etiology in adult Chinese patients

Membranous nephropathy is typically classified as idiopathic and secondary, but nowadays the number of atypical membranous nephropathy (aMN) is increasing, many of which cannot determine its etiology in China. In this study, we compared the clinical and pathological characteristics of idiopathic membranous nephropathy (iMN) with aMN with unknown etiology from a single center in China.We retrospectively reviewed the clinical data of 577 patients with iMN and aMN at Peking University People's Hospital from January 2006 to December 2015 over a 10-year period, and analyzed their clinical and pathological characteristics. The level of serum phospholipase A2 receptors (PLA2R) antibody was detected in 106 iMN and 162 aMN patients.There were 278 iMN patients and 299 aMN patients who were included into this study in 3210 cases of renal biopsy during a 10-year period in our hospital. The average age of patients with iMN was significantly older than those with aMN (54.77 ± 13.01 vs 47.13 ± 16.16, P < .001). Around 75 patients (27%) were smokers in iMN patients, and 111 patients (37.1%) in aMN patients (P = .009). The mainly clinical manifestation of these 2 groups was nephrotic syndrome (61.5% in iMN group vs 58.4% in aMN group), but there were more patients accompanied with nephritis syndrome in aMN group than iMN group (17.1% vs 6.1%, P < .001). The immunofluorescence of renal biopsy showed "full house" in aMN group; and IgG subclass of the glomeruli demonstrated IgG4 (90.4%) was commonest in iMN group, but IgG1 (94.6%) in aMN group. 51 (48.1%) patients with iMN were detected positive PLA2R antibody in their serum, and 93 (57.4%) in aMN patients (P = .168). The patients with positive PLA2R antibody had higher positive rate of microscopic hematuria and urinary protein, lower albumin.The aMN patients are younger, higher smoking rate, its main clinical manifestation is nephrotic syndrome, but more of them accompanied with nephritis syndrome than those in iMN patients. Serum PLA2R antibody could not distinguish aMN from iMN. aMN could be a special glomerular disease in China, and need a further research on a larger scale.

Smoking and the risk of diabetic nephropathy in patients with type 1 and type 2 diabetes: a meta-analysis of observational studies

Background

Conflicting evidence exists for observational studies on whether tobacco smoking is a risk factor for diabetic nephropathy (DN) in patients with type 1 (T1DM) and type 2 diabetes mellitus (T2DM). In this meta-analysis, we aimed to assess the effects of tobacco smoking on the development of DN.

Materials and Methods

We searched MEDLINE and EMBASE databases from their inception to March 31^st, 2017 for cross-sectional, case-control, and prospective cohort studies. We screened reference lists of retrieved articles. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of nineteen observational studies (1 case-control, 8 cross-sectional and 10 prospective cohort studies) were identified, involving more than 78,000 participants and a total of 17,832 DN cases. Compared with never-smokers, there was an augmented SRR (95% CI) of DN in ever-smokers in patients with T1DM (1.31 [1.06–1.62]; P = 0.006) and T2DM (1.44 [1.24–1.67]; P < 0.001), respectively. In patients with T1DM, the SRR (95% CI) was 1.25 (0.86–1.83) for microalbuminuria only, 1.27 (1.10–1.48) for macroalbuminuria only, and 1.06 (0.97–1.15) for end-stage renal disease (ESRD). In patients with T2DM, the SRR (95% CI) associated with ever smoking was 1.46 (0.94–2.26) for microalbuminuria only, 1.72 (1.04–2.84) for macroalbuminuria only, and 1.10 (0.36–3.33) for ESRD.

Conclusions

Our meta-analysis suggests evidence for cigarette smoking as an independent risk factor for the development of DN in patients with both T1DM and T2DM.

Primary glomerulonephritides

Most glomerulonephritides, even the more common types, are rare diseases. They are nevertheless important since they frequently affect young people, often cannot be cured, and can lead to chronic kidney disease, including end-stage renal failure, with associated morbidity and cost. For example, in young adults, IgA nephropathy is the most common cause of end-stage renal disease. In this Seminar, we summarise existing knowledge of clinical signs, pathogenesis, prognosis, and treatment of glomerulonephritides, with a particular focus on data published between 2008 and 2015, and the most common European glomerulonephritis types, namely IgA nephropathy, membranous glomerulonephritis, minimal change disease, focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis, and the rare complement-associated glomerulonephritides such as dense deposit disease and C3 glomerulonephritis.

Patient age and the prognosis of idiopathic membranous nephropathy

BACKGROUND

Idiopathic membranous nephropathy (IMN) is increasingly seen in older patients. However, differences in disease presentation and outcomes between older and younger IMN patients remain controversial. We compared patient characteristics between younger and older IMN patients.

METHODS

We recruited 171 Japanese patients with IMN, including 90 (52.6%) patients <65 years old, 40 (23.4%) patients 65-70 years, and 41 (24.0%) patients ≥ 71 years. Clinical characteristics and outcomes were compared between younger and older IMN patients.

RESULTS

During a median observation period of 37 months, 103 (60.2%) patients achieved complete proteinuria remission, which was not significantly associated with patient age (P = 0.831). However, 13 (7.6%) patients were hospitalized because of infection. Multivariate Cox proportional hazards models identified older age [adjusted hazard ratio (HR) = 3.11, 95% confidence interval (CI): 1.45-7.49, per 10 years; P = 0.003], prednisolone use (adjusted HR = 11.8, 95% CI: 1.59-242.5; P = 0.014), and cyclosporine used in combination with prednisolone (adjusted HR = 10.3, 95% CI: 1.59-204.4; P = 0.012) as significant predictors of infection. A <25% decrease in proteinuria at 1 month after immunosuppressive therapy initiation also predicted infection (adjusted HR = 6.72, 95% CI: 1.51-37.8; P = 0.012).

CONCLUSIONS

Younger and older IMN patients had similar renal outcomes. However, older patients were more likely to develop infection when using immunosuppressants. Patients with a poor response in the first month following the initiation of immunosuppressive therapy should be carefully monitored for infection and may require a faster prednisolone taper.