How useful is kidney biopsy for the management of glomerulopathies in the elderly?

BACKGROUND: The use of kidney biopsy in elderly individuals is still matter of discussion. The purpose of this study is to assess the utility of kidney biopsy for the management of glomerulopathies in an Eastern European cohort, targeting patients older than 65 years. METHODS: This retrospective study included 875 adults (147 older than 65 years), with biopsy-proven glomerulopathies, followed up for 71.1 (95% CI 68.2-73.9) months. The primary endpoint was chronic renal replacement therapy initiation. Statistical evaluation was performed with IBM SPSS software version 20, Analyse-it, and SAS Studio. The Kaplan-Meier method was used to estimate the time to death and the log-rank test was used for comparisons. The multivariate Cox proportional hazard analysis was used to evaluate the risk of death. RESULTS: Secondary glomerulopathies were more frequent in patients aged > 65 years (52.4% vs. 41.9%, p = 0.004). Membranous nephropathy and amyloidosis were the most frequent primary and secondary glomerulopathies in this age group. Kidney biopsy complications were low (< 4%) in both age groups. In 42% of the elderly, the result of biopsy guided the immunosuppressive therapy. While the all-cause mortality rate was higher (OR 4.2; 95% CI 2.7-6.7; p < 0.0001) in elderly individuals, the rate of renal replacement therapy initiation was similar (31.3 vs 26%; p = 0.1) in both age groups. In the competitive risk analysis, kidney survival was similar irrespective of age [CIF 0.4 (95% CI 0.26-0.53) vs. 0.34 (95% CI 0.28-0.39), p = 0.08]. However, after adjusting for the confounding factors, younger age was associated with an increased risk of renal replacement therapy (HR = 1.57, p = 0.01), along with secondary glomerulopathies. CONCLUSION: The diagnosis of an underlying glomerulopathy guided the therapy in almost one-half of the elderly patients who underwent a kidney biopsy, provided important prognostic information and had a low complications rate; kidney biopsy may therefore be considered a safe, reliable procedure in the management of glomerulopathies, even in patients over 65 years of age.

Non-diabetic glomerular lesions in diabetic kidney disease: clinical predictors and outcome in an Eastern European cohort.

PURPOSE: Since patients' prognosis depends on the lesions identified by kidney biopsy (KB), we aimed to evaluate predictors of non-diabetic kidney disease (NDKD) in diabetic subjects and to assess their kidney outcome as compared to diabetic nephropathy (DN). METHODS: 180 adults diagnosed by KB with DN (n = 120) or NDKD (n = 60), over a 10 year time-span, were retrospectively included and followed for a mean of 48.1 (95% CI 43.1-53.1) months. Patients with superimposed specific lesions over DN and with steroid-induced diabetes were excluded. The primary endpoint was renal replacement therapy (RRT) initiation. Only subjects who were alive at the end of follow-up (73 with DN and 38 with NDKD) entered the kidney survival analysis. RESULTS: Membranous nephropathy (9%) was the most common NDKD. Predictors for NDKD were shorter duration of diabetes (OR 0.88; 95% CI 0.81-0.96, p = 0.004), absence of diabetic retinopathy (OR 0.08; 95% CI 0.01-0.44, p = 0.003), and nephrotic syndrome at presentation (OR 3.55; 95% CI 1.39-9.04, p = 0.008). Subjects with NDKD needed RRT later as those with DN [82 (95% CI 67-97.1) vs. 45 (95% CI 34-56.5) months, p = 0.001]. In an adjusted Cox model, biopsy diagnosed DN independently predicted RRT (OR 4.43; 95% CI 1.54-12.7, p = 0.006). Other predictors were lower eGFR, higher proteinuria, and absence of renin-angiotensin inhibitor therapy. CONCLUSION: As one-third of the investigated subjects had NDKD, and NDKD was associated with a better kidney survival, independently predicted by the type of glomerular lesion, KB appears the most reliable tool to guide therapy and to assess outcome in patients with diabetic kidney disease.

Towards a simplified renal histopathological prognostic score in glomerular nephropathies.

AIMS: An important role of native kidney biopsy evaluation is to predict renal prognosis. We aimed to develop a simplified chronicity score based solely on pathological features that are easily recognisable and can be found in all glomerular nephropathies (GN). In this retrospective study, observational cohort study we included 625 patients with GN diagnosis after native kidney biopsy in a tertiary unit between 1 January 2010 and 31 December 2015. METHODS AND RESULTS: Presence of global glomerulosclerosis (GG), tubular atrophy (TA), interstitial fibrosis (IF) and fibrocellular/fibrous crescents (FC) in any grade was scored with one point; a final score was between 0 and 4 (i.e. 'absent' 0 score, 'moderate' 1-2 score, 'severe' 3-4 score). The primary endpoint was renal replacement therapy (RRT) initiation. Mean baseline estimated glomerular filtration rate (eGFR) was 55.9 ± 29.6 ml/min; during the follow-up (median = 27 months), 78 patients started RRT. The total mean renal survival time was 60.1 (58.0-62.1) months. GG (41%) was the most frequent lesion, followed by IF (25%), TA (18%) and FC (17%). Patients with absent (65.7; 63.6-67.8 months) chronicity had better renal survival than those with moderate (59.1; 56.1-62.2 months) or severe (42.7; 35.6-49.7 months) chronicity. The score was associated with renal survival [hazard ratio (HR) = 1.33; 1.08-1.64)] independently of the classical prognostic factors. Patients with moderate and severe chronicity had a two- and threefold increase in risk of RRT initiation. CONCLUSION: Our score was correlated with renal survival independently of the traditional risk factors, and could improve outcome prediction in patients with GN by reducing the interobserver variability.

"Associated" or "Secondary" IgA nephropathy? An outcome analysis.

BACKGROUND: Whether differences in outcome between primary (pIgAN) and secondary IgA nephropathy (sIgAN) exist is uncertain. METHODS: We conducted a retrospective, observational study that included all histologically diagnosed IgAN patients between 2010-2017 (N = 306), 248 with pIgAN and 58 with sIgAN. To obtain samples with similar risk of progression, sIgAN patients were grouped as liver disease and autoimmune/viral disease and propensity score matched to corresponding pIgAN samples. Univariate (Kaplan Meier) and multivariate time-dependent (Cox modelling) analyses were performed to identify predictors of the composite end-point (doubling of serum creatinine, end-stage kidney disease or death). RESULTS: Of the whole cohort, 20% had sIgAN (6% alcoholic cirrhosis, 6% autoimmune disease and 8% viral infections). sIgAN patients were older, had more comorbidities, lower proteinuria and higher haematuria, but similar distribution in MESTC lesions and eGFR as those with pIgAN. They reached the end-point in similar proportions with those with pIgAN (43 vs. 30%; p = 0.09) but their mortality was higher (19 vs. 3%; p<0.0001). Both in unmatched (HR 0.80, 95%CI 0.42-1.52; p = 0.5) and matched samples (log-rank test: liver disease-IgAN vs. pIgAN, p = 0.1; autoimmune/viral-IgAN vs. pIgAN, p = 0.3), sIgAN was not predictive for end-point. In analyses restricted only to sIgAN, those with viral infections (HR, 10.98; 95% CI, 1.12-107.41; p = 0.03) and lower eGFR (HR, 0.94; 95%CI, 0.89-0.98; p = 0.007) had a worse prognosis. Immunosuppression did not influence outcome. CONCLUSIONS: The differences in MESTC score and outcome between pIgAN and sIgAN seems to be minimal, suggesting that "associated" describes better than "secondary" the relationship among the two. Immunosuppression did not to influence outcome of sIgAN.

Histologic predictors of renal outcome in diabetic nephropathy: Beyond renal pathology society classification.

The prognostic utility of histologic features in patients with diabetic nephropathy (DN) classified according to the Renal Pathology Society (RPS) classification is controversial. Therefore, we aimed to evaluate the relationship between histologic changes and renal outcome in DN patients.We examined the renal outcome at November 30, 2017 of 74 adult patients (median age of 54.6 years, 69% male, 81% diabetes mellitus (DM) type 2, estimated GFR (eGFR) 29.6 mL/min) with biopsy proven DN between 2010 and 2015. The primary endpoint was renal replacement therapy (RRT) initiation.Half of the patients progressed to end stage renal disease (ESRD) during follow-up; they had lower eGFR, increased proteinuria, hematuria and serum cholesterol. Regarding the pathologic features, they were more frequently in class III and IV, had higher interstitial fibrosis and tubular atrophy score (IFTA), increased interstitial inflammation, more frequent arteriolar hyalinosis and higher glomerular basement membrane (GBM) thickness. The mean kidney survival time was 2.7 (95%CI 2.1, 3.3) years. In univariate time-dependent analyses, higher RPS DN class, increased IFTA, the presence of arteriolar hyalinosis and arteriosclerosis were associated with RRT initiation.In the fully adjusted model, the clinical characteristics associated with poor renal survival were longer duration of DM, lower eGFR, increased proteinuria and higher hematuria and the only pathologic lesions to remain significant were the GBM thickness and the IFTA.In conclusion, in this European cohort, the severity of glomerular lesions evaluated with the RPS DN classification had limited utility in predicting RRT initiation. However, IFTA and GBM thickness were significantly associated with renal survival.

Clinical and pathological considerations on renal diseases in patients with chronic viral hepatitis.

Chronic viral hepatitis B and C may associate different extrahepatic manifestations and renal disease is the most frequent. Kidney damage is represented in most cases by glomerulopathies, which include membranous nephropathy, membranoproliferative glomerulonephritis (MPGN), IgA nephropathy, focal and segmental glomerulosclerosis and diabetic nephropathy. We conducted a retrospective study on 639 patients diagnosed with chronic viral hepatitis B and C and different renal diseases. Complete evaluation of liver and renal status was performed and, in selected cases, renal biopsy. The evaluation of our cases allowed us to uncover that 82 (12.8%) patients presented a renal disease that could be linked to the viral infection. In order to identify the histopathological type of the renal lesions, kidney biopsy was performed in 39 of our patients. In hepatitis B virus (HBV) infection, the most frequent glomerulopathy was represented by membranous nephropathy, while in chronic hepatitis C infection, MPGN was responsible for the majority of glomerulonephritis. Most patients with MPGN and hepatitis C virus (HCV) also presented mixed cryoglobulinemia. Immunoglobulin A (IgA) nephropathy was present in both liver diseases while diabetic nephropathy was only found in HCV infection, in the context in which chronic hepatitis C is a risk factor for the development of type II diabetes mellitus.

Validation study of Oxford Classification of IgA Nephropathy: the significance of extracapillary hypercellularity and mesangial IgG immunostaining.

The Oxford classification (OC) of IgA Nephropathy (IgAN) identified mesangial hypercellularity (M), endocapillary hypercellularity (E), segmental glomerulosclerosis (S), and tubular atrophy/interstitial fibrosis (T) as predictors of outcome. We aimed to validate the OC and to investigate the clinical significance of extracapillary hypercellularity and IgG immunostaining. We examined the renal outcome at December 31, 2014, of 121 adult patients with biopsy proven primary IgAN between 2003 and 2013. The primary endpoint was doubling of serum creatinine or renal replacement therapy initiation. The mean observation period was 59.7 months. Thirty-one percent of the patients presented with a grade of extracapillary hypercellularity. In comparison with the group with no crescents, they had higher grade of inflammation, lower eGFR and increased proteinuria. There were no differences between the IgA and IgA&IgG immunostaining groups regarding the disease progression risk factors. Mean kidney survival time for the entire cohort was 10.6 (9.1, 12.0) years. In the Cox regression model, the independent predictors of decreased renal survival were eGFR at time of biopsy, S1 and the presence of crescents. Our study showed that extracapillary proliferation and S1 had the greatest importance in establishing the renal prognosis of patients with IgAN.

Bone marrow iron distribution, hepcidin, and ferroportin expression in renal anemia.

OBJECTIVES: The hepcidin-ferroportin system is involved in both conditions associated with iron-restricted erythropoiesis in renal anemia: iron deficiency and anemia of chronic disorders. As serum hepcidin could aid diagnosis, we investigated its relationships with bone marrow iron distribution, hepcidin-ferroportin expression in bone marrow cells, and peripheral iron indices in non-dialysis chronic kidney disease (CKD) patients. METHODS: Fifty-four epoetin and iron naive CKD patients entered this prospective, observational study. According to bone marrow iron distribution (iliac crest biopsy, Perls' stain), 26 had iron deficiency anemia, 21 anemia of chronic disorders and 7 had normal iron stores. Medullar hepcidin and ferroportin expression (immunofluorescence (IF), semiquantitative scales) and serum hepcidin (Hep25 - ELISA) were the main studied parameters. RESULTS: Low hepcidin and high ferroportin expression by erythroblast and macrophage were seen in iron deficiency anemia, while the opposites were true in anemia of chronic disorders. In regression analysis, higher Hep25 and ferritin predicted hepcidin expression (R(2)=0.48; P < 0.0001), while lower ferritin and Hep25 - predicted ferroportin expression (R(2) = 0.29; P = 0.003) by erythroblast; inflammation had no contribution. In ROC analysis, serum hepcidin and ferritin had similar moderate utility in differentiating iron deficiency anemia from anemia of chronic disorders (AUC 0.63 95% CI 0.47-0.79 and 0.76 95% CI 0.61-0.90, respectively). CONCLUSIONS: Thus, in anemic epoetin naive non-dialysis CKD patients, hepcidin and ferroportin expression by erythroblast and macrophage are closely related to bone marrow iron distribution. Although the hepcidin-ferroportin system seems regulated by ferritin-driven Hep25, serum hepcidin and peripheral iron indices are of little help in describing bone marrow iron status.

The histogenetic base of renal capsular-derived tumors.

Capsulomas comprise a category of very rare benign tumors derived from the renal capsule, the most encountered being myxomas and leiomyomas. To get more information on the histogenetic origin of these tumors, a comprehensive ultrastructural investigation on the human renal capsule has been done on kidney biopsy samples performed for nephropathologic diagnosis. The human renal capsule ultrastructure is similar to that of the mammalian renal capsule. There are two cellular layers: an inner layer made up of particular (immature) smooth muscle cells, and a second outer layer consisting of fibroblasts, collagen fibers, extracellular matrix, and telocyte-like cells. Two cases of leiomyomas of microscopic dimensions, situated beneath the capsule have been described. Data from the literature presenting the ultrastructure and perirenal location of myxomas support the affiliation of these capsulomas with the resident renal capsular cells. Based on ultrastructural studies, the authors demonstrate the presence of telocyte-like cells in the outer layer of the human renal capsule and propose distinct histogeneses for leiomyomas and for capsular myxomas as derived from the inner and outer capsular layers, respectively.

Stress-induced mast cell activation in glabrous and hairy skin.

Mast cells play a key role in modulation of stress-induced cutaneous inflammation. In this study we investigate the impact of repeated exposure to stress on mast cell degranulation, in both hairy and glabrous skin. Adult male Wistar rats were randomly divided into four groups: Stress 1 day (n = 8), Stress 10 days (n = 7), Stress 21 days (n = 6), and Control (n = 8). Rats in the stress groups were subjected to 2 h/day restraint stress. Subsequently, glabrous and hairy skin samples from animals of all groups were collected to assess mast cell degranulation by histochemistry and transmission electron microscopy. The impact of stress on mast cell degranulation was different depending on the type of skin and duration of stress exposure. Short-term stress exposure induced an amplification of mast cell degranulation in hairy skin that was maintained after prolonged exposure to stress. In glabrous skin, even though acute stress exposure had a profound stimulating effect on mast cell degranulation, it diminished progressively with long-term exposure to stress. The results of our study reinforce the view that mast cells are active players in modulating skin responses to stress and contribute to further understanding of pathophysiological mechanisms involved in stress-induced initiation or exacerbation of cutaneous inflammatory processes.

Desmosomes as markers for the proliferating parietal epithelial cells in collapsing glomerulosclerosis. A case report.

Two variants of focal segmental glomerulosclerosis are known to present epithelial hypercellularity in the Bowman's space, namely the collapsing and the cellular types. This epithelial cell proliferation may get features of either pseudocrescent or tubular profiles. Our case of collapsing focal segmental glomerulosclerosis has been ultrastructurally investigated concerning the proliferating epithelial cell type: parietal versus visceral. Based on the cellular organelles, especially on the ubiquitous presence of desmosomes, the authors are endorsing, with ultrastructural arguments, the opinion favoring the parietal epithelial cells (PEC) as the proliferating cell type. It is also taken into consideration the eventual change of PECs phenotype in contact with the glomerular tuft components like the glomerular basement membrane.

Acute pancreatitis, acute hepatitis and acute renal failure favourably resolved in two renal transplant recipients.

Renal transplantation is often associated with severe complications. Except for acute rejection, infections and toxicity of immunosuppressive treatment are the most frequent problems observed after transplantation. Infections with hepatic viruses (HBV, HDV, HCV, HGV) and cytomegalic virus (CMV) are the main infectious complications after renal transplantation. Cyclosporine toxicity is not unusual for a patient with renal transplantation and is even more frequent for patients with hepatic impairment due to viral infections. The subjects of this report are two renal transplant recipients with acute pancreatitis, severe hepatitis and acute renal failure on graft, receiving immunosuppressive therapy for maintaining renal graft function