Clinical and pathologic features of primary membranous nephropathy in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group.

BACKGROUND: We aimed to evaluate the features of primary membranous nephropathy (MNP) in Turkish people. METHODS: This is a retrospective analysis of patients with biopsy-proven primary MNP. We obtained the data collected between 2009 and 2019 in the primary glomerulonephritis registry of the Turkish Society of Nephrology Glomerular Diseases Study Group (TSN-GOLD). Patients with a secondary cause for MNP were excluded. Clinical, demographic, laboratory, and histopathological findings were analyzed. RESULTS: A total of 995 patients with primary MNP were included in the analyses. Males constituted the majority (58.8%). The mean age was 48.4 ± 13.9 years. The most common presentation was the presence of nephrotic syndrome (81.7%) and sub nephrotic proteinuria (10.3%). Microscopic hematuria was detected in one-third of patients. The median estimated glomerular filtration rate (eGFR) was 100.6 mL/min/1.73 m2 (IQR, 75.4-116.3), and median proteinuria was 6000 mg/d (IQR, 3656-9457). Serum C3 and C4 complement levels were decreased in 3.7 and 1.7% of patients, respectively. Twenty-four (2.4%) patients had glomerular crescents in their kidney biopsy samples. Basal membrane thickening was detected in 93.8% of cases under light microscopy. Mesangial proliferation and interstitial inflammation were evident in 32.8 and 55.9% of the patients, respectively. The most commonly detected depositions were IgG (93%), C3 complement (68.8%), and kappa and lambda immunoglobulin light chains (70%). Although renal functions were normal at presentation, vascular, interstitial, and glomerular findings were more prominent on biopsy in hypertensive patients. No significant effect of BMI on biopsy findings was observed. CONCLUSIONS: Despite some atypical findings, the main features of primary MNP in Turkey were similar to the published literature. This is the largest MNP study to date conducted in Turkish people.

The Effect of Smoking on Endothelial Dysfunction in Autosomal Dominant Polycystic Kidney Disease Patients with Preserved Renal Function.

BACKGROUND: In autosomal dominant polycystic kidney disease (ADPKD), endothelial dysfunction (ED) is common and occurs much earlier than kidney function impairment. The impact of smoking on ED in ADPKD patients has not been previously studied. The aim of this study was to investigate the potential contribution of smoking habits to ED and subclinical atherosclerosis in these patients. METHODS: This case-control study included 54 ADPKD patients with preserved renal function and 45 healthy control subjects. ED was assessed using ischemia-induced forearm flow-mediated dilatation (FMD). Carotid intima-media thickness (CIMT) was measured from 10 mm proximal to the right common carotid artery. Clinical demographic characteristics and laboratory data were recorded for the patients and control group. Regression analysis was used to determine independent associations of ED and CIMT. RESULTS: FMD was significantly lower in the ADPKD patients (19.5 ± 5.63 vs. 16.56 ± 6.41, p = .018). Compared with nonsmoker ADPKD patients, smoker patients had significantly lower FMD values (18.19 ± 6.52 vs. 13.79 ± 5.27, p = .013). In multiple regression analysis, age (ß = -0.294, 95% CI: -0.392: -1.96, p = .001) for FMD and smoking (ß = 1.328, 95% CI: 0.251, 2.404, p = .017) for CIMT were independent predictors. CONCLUSIONS: Patients with ADPKD had more impaired endothelial function and subclinical atherosclerosis compared with control subjects. Smoking may increase the risk of subclinical atherosclerosis in ADPKD patients.

Characteristics of primary glomerular diseases patients with hematuria in Turkey: the data from TSN-GOLD Working Group.

PURPOSE: Hematuria is one of the most common laboratory findings in nephrology practice. To date, there is no enough data regarding the clinical and histopathologic characteristics of primary glomerular disease (PGD) patients with hematuria in our country. METHODS: Data were obtained from national multicenter (47 centers) data entered into the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database between May 2009 and June 2019. The data of all PGD patients over the age of 16 years who were diagnosed with renal biopsy and had hematuria data were included in the study. Demographic characteristics, laboratory and biopsy findings were also recorded. RESULTS: Data of 3394 PGD patients were included in the study. While 1699 (50.1%) patients had hematuria, 1695 (49.9%) patients did not have hematuria. Patients with hematuria had statistically higher systolic blood pressure, serum blood urea nitrogen, creatinine, albumin, levels and urine pyuria. However, these patients had statistically lower age, body mass index, presence of hypertension and diabetes, eGFR, 24-h proteinuria, serum total, HDL and LDL cholesterol, and C3 levels when compared with patients without hematuria. Hematuria was present 609 of 1733 patients (35.8%) among the patients presenting with nephrotic syndrome, while it was presented in 1090 of 1661 (64.2%) patients in non-nephrotics (p < 0.001). CONCLUSION: This is the first multicenter national report regarding the demographic and histopathologic data of PGD patients with or without hematuria. Hematuria, a feature of nephritic syndrome, was found at a higher than expected in the PGDs presenting with nephrotic syndrome in our national database.

The Comparison Spondin 2 Levels in Primary Glomerular Diseases.

Spondin 2 (SPON2) plays an important role in multiple processes and is a member of the Spondin 2/F-spondin family of extracellular matrix proteins. We investigated serum SPON2 levels and its correlation with renal functions and urine protein excretion in different glomerular diseases. The cohort included 97 consecutive adults with persistant proteinuria (>300 mg/day) with the diagnosis of focal segmental glomerulosclerosis (FSGS), membranous glomerulonephritis (MN), IgA nephropathy (IgAN), membranoproliferative glomerulonephritis (MPGN), and AA amyloidosis and the control groups with 15 polycystic kidney disease (PKD) and 32 healthy people. Serum SPON2 levels in MN (64.6 ng/mL), FSGS (47.8 ng/mL), IgAN (52.6 ng/mL), MPGN (54.6 ng/mL), and AA amyloidosis (60.7 ng/mL) groups were higher than those of the control (26.4 ng/mL) and nonglomerular disease groups (PKD) (15.3 ng/mL). Only serum SPON2 levels were correlated with serum uric acid and triglyceride levels in patients with glomerular disease. This is the first study to show that serum SPON2 levels are similar in different glomerular diseases and that there is no correlation between SPON2 and proteinuria grade.

Clinical outcomes and survival in AA amyloidosis patients / Desfechos clínicos e sobrevida em pacientes com amiloidose AA

Abstract Aim Amyloid A amyloidosis is a rare complication of chronic inflammatory conditions. Most patients with amyloid A amyloidosis present with nephropathy and it leads to renal failure and death. We studied clinical characteristics and survival in patients with amyloid A amyloidosis. Methods: A total of 81 patients (51 males, 30 females) with renal biopsy proven amyloid A amyloidosis were analyzed retrospectively. The patients were divided into good and poor outcomes groups according to survival results. Results: Most of the patients (55.6%) had nephrotic range proteinuria at diagnosis. Most frequent underlying disorders were familial Mediterranean fever (21.2%) and rheumatoid arthritis (10.6%) in the good outcome group and malignancy (20%) in the poor outcome group. Only diastolic blood pressure in the good outcome group and phosphorus level in the poor outcome group was higher. Serum creatinine levels increased after treatment in both groups, while proteinuria in the good outcome group decreased. Increase in serum creatinine and decrease in estimated glomerular filtration rate of the poor outcome group were more significant in the good outcome group. At the time of diagnosis 18.5% and 27.2% of all patients had advanced chronic kidney disease (stage 4 and 5, respectively). Median duration of renal survival was 65 ± 3.54 months. Among all patients, 27.1% were started dialysis treatment during the follow-up period and 7.4% of all patients underwent kidney transplantation. Higher levels of systolic blood pressure [hazard ratios 1.03, 95% confidence interval: 1-1.06, p = 0.036], serum creatinine (hazard ratios 1.25, 95% confidence interval: 1.07-1.46, p = 0.006) and urinary protein excretion (hazard ratios 1.08, 95% confidence interval: 1.01-1.16, p = 0.027) were predictors of end-stage renal disease. Median survival of patients with organ involvement was 50.3 ± 16 months. Conclusion Our study indicated that familial Mediterranean fever constituted a large proportion of cases and increased number of patients with idiopathic amyloid A amyloidosis. Additionally, it was observed that patient survival was not affected by different etiological causes in amyloid A amyloidosis.

Resumo Objetivo: A amiloidose AA é uma complicação rara de condições inflamatórias crônicas. A maior parte dos pacientes com amiloidose AA apresenta nefropatia, que leva à insuficiência renal e à morte. Estudaram-se as características clínicas e a sobrevida em pacientes com amiloidose AA. Métodos: Analisaram-se retrospectivamente 81 pacientes (51 homens, 30 mulheres) com amiloidose AA comprovada por biópsia renal. Os pacientes foram divididos em grupos de desfecho bom e ruim de acordo com os resultados de sobrevida. Resultados: A maior parte dos pacientes (55,6%) tinha proteinúria na faixa nefrótica no momento do diagnóstico. Os distúrbios subjacentes mais frequentes foram a febre familiar do Mediterrâneo (FFM, 21,2%) e a artrite reumatoide (10,6%) no grupo de desfecho bom e a malignidade (20%) no grupo de desfecho ruim. Somente a pressão arterial diastólica no grupo de desfecho bom e o nível de fósforo no grupo de desfecho ruim foram mais elevados. Os níveis séricos de creatinina aumentaram após o tratamento em ambos os grupos, enquanto a proteinúria diminuiu no grupo de desfecho bom. O aumento na creatinina sérica e a diminuição na TFGe do grupo de desfecho ruim foram mais significativos no grupo de desfecho bom. No momento do diagnóstico, 18,5% e 27,2% de todos os pacientes tinham doença renal crônica avançada (estágios 4 e 5, respectivamente). A duração média da sobrevida renal foi de 65 ± 3,54 meses. Entre todos os pacientes, 27,1% iniciaram tratamento de diálise durante o período de seguimento e 7,4% de todos os pacientes foram submetidos a transplante renal. Níveis elevados de pressão arterial sistólica [taxas de risco (HR) 1,03, intervalo de confiança (IC) de 95%: 1 a 1,06, p = 0,036], creatinina sérica (HR 1,25, IC 95%: 1,07 a 1,46, p = 0,006) e excreção urinária de proteínas (HR 1,08, IC 95%: 1,01 a 1,16, p = 0,027) foram preditores de doença renal terminal. A mediana da sobrevida de pacientes com comprometimento de órgãos foi de 50,3 ± 16 meses. Conclusão: O presente estudo indicou que a FFM constituiu uma grande proporção de casos e crescente quantidade de pacientes com amiloidose AA idiopática. Adicionalmente, observou-se que a sobrevida do paciente não foi afetada pelas diferentes causas etiológicas na amiloidose AA.

Clinical outcomes and survival in AA amyloidosis patients.

AIM: Amyloid A amyloidosis is a rare complication of chronic inflammatory conditions. Most patients with amyloid A amyloidosis present with nephropathy and it leads to renal failure and death. We studied clinical characteristics and survival in patients with amyloid A amyloidosis. METHODS: A total of 81 patients (51 males, 30 females) with renal biopsy proven amyloid A amyloidosis were analyzed retrospectively. The patients were divided into good and poor outcomes groups according to survival results. RESULTS: Most of the patients (55.6%) had nephrotic range proteinuria at diagnosis. Most frequent underlying disorders were familial Mediterranean fever (21.2%) and rheumatoid arthritis (10.6%) in the good outcome group and malignancy (20%) in the poor outcome group. Only diastolic blood pressure in the good outcome group and phosphorus level in the poor outcome group was higher. Serum creatinine levels increased after treatment in both groups, while proteinuria in the good outcome group decreased. Increase in serum creatinine and decrease in estimated glomerular filtration rate of the poor outcome group were more significant in the good outcome group. At the time of diagnosis 18.5% and 27.2% of all patients had advanced chronic kidney disease (stage 4 and 5, respectively). Median duration of renal survival was 65±3.54 months. Among all patients, 27.1% were started dialysis treatment during the follow-up period and 7.4% of all patients underwent kidney transplantation. Higher levels of systolic blood pressure [hazard ratios 1.03, 95% confidence interval: 1-1.06, p=0.036], serum creatinine (hazard ratios 1.25, 95% confidence interval: 1.07-1.46, p=0.006) and urinary protein excretion (hazard ratios 1.08, 95% confidence interval: 1.01-1.16, p=0.027) were predictors of end-stage renal disease. Median survival of patients with organ involvement was 50.3±16 months. CONCLUSION: Our study indicated that familial Mediterranean fever constituted a large proportion of cases and increased number of patients with idiopathic amyloid A amyloidosis. Additionally, it was observed that patient survival was not affected by different etiological causes in amyloid A amyloidosis.

Immunosuppressive Treatment in C3 Glomerulopathy: Is it Really Effective?

BACKGROUND: C3 glomerulopathy (C3GP) is a recently identified and described disease that has a high risk of progressing into end-stage renal disease. We aimed to evaluate the effects of various immunosuppressive regimens on C3GP progression because there are conflicting data on the treatment modalities. METHODS: In this retrospective study of 66 patients with C3GP, 27 patients received mycophenolate mofetil (MMF)-based treatment, 23 received non-MMF-based treatment (prednisolone or cyclophosphamide), and 16 received conservative care. The study groups were compared with each other with specific focus on primary outcomes defined as (1) kidney failure and (2) estimated glomerular filtration rate (eGFR) decline ≥50% from the baseline value. RESULTS: Overall, 17 (25.8%) patients reached the primary outcome after a median period of 28 months. The number of patients who reached the primary outcome were similar among the study groups (MMF-based: 8/27 [29.6%], non-MMF-based: 4/23 [17.4%], and conservative care: 5/16 [31.3%], p = 0.520). In the Cox regression analysis, age (HR 0.912, p = 0.006), eGFR (HR 0.945, p = 0.001), and proteinuria levels (HR 1.418, p = 0.015) at the time of biopsy, percentage of crescentic (HR 1.035, p = 0.001) and sclerotic glomeruli (HR 1.041, p = 0.006), severity of interstitial fibrosis (HR 1.981, p = 0.048), as well as no remission of proteinuria (HR 2.418, p = 0.002) predicted the primary outcome. CONCLUSION: Although patients receiving immunosuppressive treatments had higher proteinuria and lower serum albumin at baseline, there were no differences between these patients and those receiving conservative care alone in proteinuria remission or in the decline of renal function. Younger age, higher proteinuria, lower eGFR, and the presence of crescentic and sclerotic glomeruli, severity of interstitial fibrosis, and no remission of proteinuria predicted the progression of kidney disease.

Ki-67 proliferation index in renal biopsy samples of patients with systemic lupus erythematosus and its correlation with clinical findings.

INTRODUCTION: Systemic lupus erythematosus is an autoimmune disease that may affect almost all organ systems. Renal involvement is the most significant prognostic factor. Renal biopsy findings play an important role in treatment decision. Ki-67 is a monoclonal antibody that is only found in proliferative cells. This study aimed to investigate the proliferative activity in renal biopsy specimens of patients with lupus nephritis using the Ki-67 monoclonal antibody, and to compare the proliferative index between different subgroups of patients. MATERIALS AND METHODS: Renal biopsy specimens of 29 patients with systemic lupus erythematosus were retrospectively evaluated. Type of lupus nephritis and activity and chronicity indexes were determined. Ki-67 immunostaining was performed. For each patient, 1000 cells were counted and the number of Ki-67 positive cells was determined. The Ki-67 activity index was compared between different subgroups of lupus nephritis and correlated with systemic lupus erythematosus disease activity index, serum creatinine, proteinuria, anticardiolipin antibodies, and complement levels. RESULTS: A positive correlation between Ki-67 proliferation index, serum creatinine levels, and systemic lupus erythematosus disease activity index were found. Although conventional activity indexes were low, in 3 of 9 patients with class II lupus nephritis, Ki-67 proliferation indexes were high, indicating proliferation. CONCLUSIONS: Ki-67 can be used as a proliferation marker in renal biopsy specimens for patients diagnosed with systemic lupus erythematosus.