A comparison of the epidemiology of kidney replacement therapy between Europe and the United States: 2021 data of the ERA Registry and the USRDS

BACKGROUND AND HYPOTHESIS

This paper compares the most recent data on the incidence and prevalence of kidney replacement therapy (KRT), kidney transplantation rates, and mortality on KRT from Europe to those from the United States (US), including comparisons of treatment modalities (haemodialysis (HD), peritoneal dialysis (PD), and kidney transplantation (KTx)).

METHODS

Data were derived from the annual reports of the European Renal Association (ERA) Registry and the United States Renal Data System (USRDS). The European data include information from national and regional renal registries providing the ERA Registry with individual patient data. Additional analyses were performed to present results for all participating European countries together.

RESULTS

In 2021, the KRT incidence in the US (409.7 per million population (pmp)) was almost 3-fold higher than in Europe (144.4 pmp). Despite the substantial difference in KRT incidence, approximately the same proportion of patients initiated HD (Europe: 82%, US: 84%), PD (14%; 13% respectively), or underwent pre-emptive KTx (4%; 3% respectively). The KRT prevalence in the US (2436.1 pmp) was 2-fold higher than in Europe (1187.8 pmp). Within Europe, approximately half of all prevalent patients were living with a functioning graft (47%), while in the US, this was one third (32%). The number of kidney transplantations performed was almost twice as high in the US (77.0 pmp) compared to Europe (41.6 pmp). The mortality of patients receiving KRT was 1.6-fold higher in the US (157.3 per 1000 patient years) compared to Europe (98.7 per 1000 patient years).

CONCLUSIONS

The US had a much higher KRT incidence, prevalence, and mortality compared to Europe, and despite a higher kidney transplantation rate, a lower proportion of prevalent patients with a functioning graft.

DNAJB9 Fibrillary Glomerulonephritis With Membranous-Like Pattern: A Case-Based Literature Review

Fibrillary glomerulonephritis (FGN) is a rare immune-mediated glomerular disease traditionally characterized by the presence of amyloid-like, randomly aligned, fibrillary deposits in the capillary wall, measuring approximately 20 nm in diameter and composed of polyclonal IgG. FGN is usually a primary disease with no pathognomonic clinical or laboratory findings. More than that, on light microscopic evaluation, it can receive various histological patterns, rendering its diagnosis indistinguishable. However, the identification by immunohistochemistry of a novel biomarker, DNA-J heat-shock protein family member B9 (DNAJB9), has created a new era in FGN diagnosis even in the absence of electron microscopy. Typically, most patients manifest various degrees of renal insufficiency, hypertension, microscopic hematuria, proteinuria, and occasionally frank nephrotic syndrome. The prognosis is usually severe and progression to end-stage kidney disease (ESKD) is the rule, given that no specific treatment is available until now, despite the fact that in small studies rituximab-based therapy seems to alleviate the severity and improve the disease progression. Herein, we report the case of a 63-year-old Caucasian man presenting with uncontrolled hypertension, headache, shortness of breath, and lower limb edema. Diagnostic evaluation revealed mild deterioration of kidney function, nephrotic range proteinuria, and faint IgGκ monoclonal bands in serum and urine immunofixation. After negative meticulous investigation for secondary nephrotic syndrome causes, the patient underwent a kidney biopsy. Biopsy sample showed two glomeruli with mesangial expansion and thickened glomerular basement membrane (GBM) on light microscopy, a pattern masquerading as membranous nephropathy stage III-IV, while IgG and C3 were 1-2+ on GBM and mesangium in immunofluorescence. Thickened GBM with fibrils on electron microscopy were found, while DNAJB9 in immunohistochemistry was positive, confirming FGN. Once diagnosis of FGN was made, a combination of steroids with rituximab was initiated while the patient was receiving the standard anti-hypertensive therapy, simultaneously with a sodium-glucose cotransporter-2 (SGLT2) inhibitor. The 12-month follow-up showed approximately 85% decrease in proteinuria alongside stabilization of kidney function and blood pressure normalization. Hence, in this article, we aim to highlight that DNAJB9-associated FGN may mimic membranous glomerulopathy stage III-IV on light microscopy, especially when a small kidney sample with extensive involvement by fibrils of GBM is examined. Moreover, we underscore the fact that ultramicroscopic examination is of crucial importance in the differential diagnosis of glomerular deposition diseases and that DNAJB9 identification on immunohistochemistry consists of a revolutionary and robust biomarker in FGN diagnosis.

The effects of sex steroids on bone via extraskeletal actions

Sex steroids have direct effect on bone via their action on the estrogen and androgen receptors of bone cells. However, there is emerging evidence that their indirect actions on bone can play also important role in the pathogenesis of osteoporosis and bone loss in inflammatory diseases. The tissues that are involved in the extraskeletal actions of sex hormones and are better studied in the past few decades are adipose tissue, muscle tissue and the immune system. Key regulators on those complex pathways are molecules such as cytokines, adipokines and reactive oxygen species.

Histological grading in primary membranous nephropathy is essential for clinical management and predicts outcome of patients

Aims

Diagnosis of primary membranous nephropathy (PMN) is mainly based on immunofluorescence/immunohistochemistry findings. However, assessment of specific features on optical microscopy can help to estimate the severity of the disease, guide treatment and predict the response. The aim of this study was to identify, classify and grade the precise histological findings in PMN to predict renal function outcome and guide treatment.

Methods and results

Histological parameters, including focal segmental sclerosis (FSGS), tubular atrophy (TA), interstitial fibrosis (IF) and vascular hyalinosis (VH), were re‐evaluated in 752 patients with PMN. Their predictive value was estimated separately, and also in a combination score (FSTIV) graded from 0 to 4. Finally, the impact of histology was assessed in the response to immunosuppressive treatment. Mean age of patients was 53.3 (15–85) years and most presented with nephrotic syndrome. FSGS was present in 32% and VH in 51% of the patients, while TA and IF were graded as stage ≥1 in 52% and 51.4%, respectively. The follow‐up period was 122.3 (112–376) months. FSGS, TA and IF and VH were associated with impaired renal function at diagnosis (P = 0.02, P < 0.0001, P = 0.001 and P = 0.02, respectively) and at the end of follow‐up (P = 0.004, P < 0.0001, P < 0.0001 and P = 0.04, respectively). In multiple regression and binary logistic analysis, the presence of FSGS and degree of TA were the most significant parameters predicting renal function outcome, defined either by eGFR (end), FSGS (r = 0.6, P < 0.0001) and TA (r = 0.6, P < 0.0001), or by the endpoint of >50% eGFR reduction, FSGS (P = 0.001) and TA (P = 0.02). Also, patients presented with FSGS, IF, VH and/or with FSTIV > 1 could benefit from immunosuppression, regardless of clinical presentation.

Conclusions

The presence and degree of four histological indices, FSGS, VH, TA and IF, assessed separately or in combination, and FSTIV score not only predict renal function outcome after long‐term follow‐up, but can also help in the choice of appropriate treatment. Decisions concerning immunosuppressive treatment can be guided by pathology regardless of clinical findings.

Immunosuppressive regimens based on Cyclophospamide or Calcineurin inhibitors: Comparison of their effect in the long term outcome of Primary Membranous Nephropathy

INTRODUCTION

Management of the Primary Membranous Nephropathy (PMN) usually involves administration of immunosuppressives. Cyclophosphamide (Cyclo) and Calcineurin Inhibitors (CNIs) are both widely used but only limited data exist to compare their efficacy in long term follow-up.

AIM

The aim of the present study was to estimate and compare long term effects of Cyclo and CNIs in patients with PMN.

PATIENTS-METHODS

Clinical data, histologic findings and long term outcome were retrospectively studied. The response to treatment and rate of relapse was compared between patients treated with CNIs or Cyclo based immunosuppressive regimens.

RESULTS

Twenty three centers participated in the study, with 752 PMN patients (Mean age 53.4(14-87) yrs, M/F 467/285), followed for 10.1±5.7 years. All patients were initially treated with Renin Angiotensin Aldosterone System inhibitors (RAASi) for at least 6 months. Based on their response and tolerance to initial treatment, patients were divided into 3 groups, group I with spontaneous remission, who had no further treatment, group II, continued on RAASi only, and group III on RAASi+immunosuppression. Immunosuppressive regimes were mainly based on CNIs or Cyclo. Frequent relapses and failure to treatment were more common between patients who had started on CNIs (n = 381) compared to those initially treated with Cyclo (n = 110), relapse rate: 25.2% vs. 6.4%, p<0.0001, and no response rate: 22.5% vs. 13.6%, p = 0.04, respectively.

CONCLUSIONS

Long term follow up showed that administration of Cyclo in PMN is followed by better preservation of renal function, increased response rate and less frequent relapses, compared to CNIs.

The role of serum osteoprotegerine in metastatic prostate cancer - a case control study

INTRODUCTION

Prostate cancer is one of the most common malignant neoplastic diseases in men. Early control of the disease progression contributes significantly to survival rates and patients' quality of life. Osteoprotegerin is a dimeric glycoprotein, which affects bone metabolism and inhibits osteoclastogenesis. In the present study, we evaluated the expression of osteoprotegerin in the serum of prostate cancer patients with or without skeletal metastases.

METHODS

The expression of serum osteoprotegerin, as measured by enzyme-linked immunosorbent assay, has been studied in 82 patients with locally controlled prostate cancer, in 49 patients with metastatic bone disease and in a control group of 41 healthy males. At sampling time 65/131 of included patients were newly diagnosed, while 66/131 patients were already under hormonal therapy. All eligible prostate cancer patients had histologically confirmed malignancy. Serum total prostate-specific antigen (PSA) was determined by an immunoradiometric assay. We investigated the expression of osteoprotegerin in hormone-dependent and hormone-refractory prostate cancer and its relation to disease progression.

RESULTS

Among the 131 patients with prostate cancer, higher osteoprotegerin and PSA concentrations have been observed in metastatic bone patients' sera (p <0.001). ROC analysis between the metastatic and locally controlled prostate cancer patients has shown a statistically significant area curve (p <0.001) and a cut-off limit of 89.6 pg/ml. Moreover, 15.3 % of patients became hormone-resistant, with osteoprotegerin values significantly increased compared with hormone-sensitive prostate cancer patients (p <0.001).

CONCLUSIONS

It seems that elevated levels of serum osteoprotegerin in patients with prostate cancer reflect the bone metastatic extent and may potentially be used in metastatic patients' follow-ups. Hippokratia 2016, 20(2): 133-138.

Genetic predisposition to left ventricular hypertrophy and the potential involvement of cystatin-C in untreated hypertension

BACKGROUND

The angiotensinogen M235T and aldosterone synthase C-344T gene polymorphisms have been associated with cardiac and structure function. However, these associations in untreated hypertension remain unknown. We examined whether these variants determined both echocardiography indices and the potential associated underlying mechanisms, including cystatin-C and vascular inflammation.

METHODS

The study population consisted of 319 untreated patients and 191 healthy individuals. Polymorphisms were determined by polymerase chain reaction technique. Left cardiac indices of geometry and function were assessed by echocardiography. Cystatin-C, intracellular cell adhesion molecule 1, and vascular cell adhesion molecule 1 levels were measured by enzyme-linked immunosorbent assay, whereas high sensitivity C-reactive protein levels were measured by immunonephelometry.

RESULTS

There was no significant interaction between the angiotensinogen genotypes on left ventricular mass index (LVMI) and diastolic function indices in all study groups. Regarding C-344T polymorphism, TT homozygous hypertensive subjects exhibited higher values of LVMI compared with C allele carriers (P = 0.02) and higher prevalence of concentric hypertrophy (P < 0.001). However, this polymorphism was not associated with variations in left atrial volume and diastolic dysfunction. Cystatin-C levels were correlated with LVMI values (r = 0.22; P = 0.002) and mean E/A ratio (r = -0.24; P < 0.001). Interestingly, a linear increase of LVMI with cyctatin-C quartiles has been revealed (F = 5.01; P < 0.001). Moreover, post hoc tests showed that increased levels of cystatin-C (above 75th percentile) were significantly different between both the first (P = 0.009) and the second quartile (P = 0.02).

CONCLUSIONS

We have shown that C-344T potentially predicts higher values of LVMI and concentric hypertrophy in untreated hypertension, independently of renal function and subclinical inflammation. Increased levels of cystatin-C were correlated with higher LVMI values.

Intestinal schistosomiasis caused by both Schistosoma intercalatum and Schistosoma mansoni

A case is presented of intestinal schistosomiasis due to both Schistosoma intercalatum and Schistosoma mansoni in a 30-year-old man from Senegal with discussion of diagnostic approach, species identification and determination of the effect of treatment. The patient was admitted to hospital for investigation of renal failure, arterial hypertension and hypereosinophilia. Repeated stool examinations for ova and parasites were negative. Ultrasonography (US) and computed tomography (CT) of the abdomen showed no abnormalities. US of the urinary tract showed kidneys of borderline size with increased echogenicity. Cystoscopy and histopathological examination of bladder biopsy specimens were normal. Flexible colonoscopy revealed numerous nodular lesions in the rectosigmoid region and a few similar lesions in the transverse colon, the histopathological examination of which showed deposition of Schistosoma ova with granuloma formation. Examination of multiple crush biopsy specimens from the rectosigmoid region revealed numerous granulomas formed around Schistosoma eggs which had a terminal spine and were identified as S. intercalatum (longer than Schistosoma haematobium and with a slightly curved terminal spine) and a very few S. mansoni eggs. Crush biopsies from the lesions in the transverse colon showed only S. mansoni eggs. In conclusion, the examination of multiple crush biopsy specimens is a very sensitive and specific technique for species identification of Schistosoma, especially in mixed infections, and for defining the location and extent of the granulomas evoked by each species.

Catastrophic antiphospholipid syndrome in a 14-year-old child

Antiphospholipid syndrome (APS) is an autoimmune disease. Less than 1% of patients with APS present with life-threatening catastrophic APS (CAPS). We report here a case of CAPS in a young girl with cardiac, gastrointestinal and renal involvement. Although the management was complicated, the outcome was better than expected. We suggest that CAPS be included in the differential diagnosis of acute renal failure in children with multi-organ involvement and prolonged phospholipid-dependent coagulation time and promptly treated with immunomodulating agents and anticoagulants.

Myofibroblasts and the progression of crescentic glomerulonephritis

BACKGROUND

The cellular and humoral factors involved in the pathogenesis of glomerulosclerosis and renal fibrosis following a crescentic glomerulonephritis have not been fully elucidated. Myofibroblasts and transforming growth factor-beta (TGF-beta) have been implicated in the development of experimental and clinical renal fibrosis. We have attempted to identify these mediators in crescentic glomerulonephritis and determine their role in the progression of the disease.

PATIENTS AND METHODS

We studied retrospectively 21 patients with crescentic and necrotizing glomerulonephritis (CNG) with emphasis on the renal expression (detected by immunohistochemistry) of myofibroblasts (alpha-smooth muscle actin+ cells), TGF-beta and collagen (III and IV) as well as their relationship with the clinical outcome of these patients. In situ hybridization histochemistry was applied to determine the site of synthesis of TGF-beta1 and collagen III. All the patients were treated by immunosuppression and followed up for a median period of 14 months.

RESULTS

Myofibroblasts and TGF-beta were detected in the crescents as well as in the periglomerular and tubulointerstitial areas in CNG biopsies. TGF-beta1 was also detected within renal tubular cells. The percentage of glomeruli with fibrotic and fibrocellular crescents was positively correlated with the severity of Bowman's capsule disruption (r = 0.631, P < 0.01) and with the intensity of myofibroblast expression in the interstitium (r = 0.504, P < 0.05). Strong interstitial immunostain for myofibroblasts and TGF-beta was also noted in association with interstitial fibrosis. In situ hybridization revealed the site of synthesis of TGF-beta1 to be the renal tubular cells of patients with CNG. By contrast, the site of synthesis of collagen III appeared to be confined to interstitial cells surrounding vessels, tubules and the glomeruli in a distribution identical to that of myofibroblasts. There was a significant positive correlation between the number of interstitial alpha-SMA+ cells and both interstitial TGF-beta (r = 0.591, P < 0.01) and interstitial collagen IV (r = 0.588, P < 0.01). In addition, the number of interstitial alpha-SMA+ cells and the extent of immunostain for collagen IV were positively correlated with the final serum creatinine (r = 0.517, P < 0.05 and r = 0.612, P < 0.01 respectively) and partially predicted functional outcome (R2 = 26.7% and 37.5% respectively) as well as the response to treatment. An association was observed between periglomerular myofibroblasts and the generation of fibrotic and fibrocellular crescents.

CONCLUSION

These observations suggest a causal link between myofibroblasts and fibrotic crescent formation. We also believe that interstitial myofibroblasts are actively involved in the pathogenesis of interstitial fibrosis in CNG.

Platelet-activating factor levels and PAF acetylhydrolase activities in patients with primary glomerulonephritis

Platelet-activating factor (PAF) belongs to a new class of lipid chemical inflammatory mediators described as acetyl glyceryl ether phosphorylcholine. Although PAF has been implicated in kidney injury, its role in renal immune injury has not been clearly defined yet. We studied the levels of PAF in the plasma and urine and acetylhydrolase (AH) activities in serum and in renal tissue (cortex, C and medulla, M) in patients with primary glomerulonephritis (PGN). PAF levels in the plasma and urine and AH activity in serum of normal volunteers as well as AH activities in normal renal parenchyma (C and M) from nephrectomized patients (served as control) were also measured. Our results demonstrate increased PAF levels in the plasma and urine as well as increased AH activity in serum in patients with PGN in comparison to normal volunteers. AH activity in cortex of those patients was diminished compared to normal kidney tissue. We propose that the enhanced AH activity in serum in patients with PGN could be due to hyperproduction and low degradation of PAF in nephritic tissue which on one hand results in enhanced PAF levels in the plasma and in urine and on the other hand results in enhanced serum AH activity by virtue of substrate (PAF) availability. These data provide new knowledge in the homeostasis of PAF and its degrative enzyme in the setting of PGN.

Platelet-activating factor acetylhydrolase (PAF-AH) in human kidney

1. PAF-AH activity in human kidney (cortex and medulla) has been demonstrated and shares the following properties. 2. Does not require the presence of Ca2+ and appears to be different from phospholipase A2. 3. The pH optimum shows a peak at 7-7.4. 4. It is stable for 4 days at -30 degrees C. 5. It is mainly distributed in the microsomal fraction. 6. The apparent Km values of the enzymes of cortex and medulla are 0.553 and 0.207 microM, respectively and distinct from serum PAF-AH (1.439 microM). 7. The apparent molecular weight values are 60,000 and 25,000 for medulla and cortex, respectively and distinct from serum PAF-AH (94,000).