Immunohistochemical Expression of FOXP3+ Regulatory T Cells in Proteinuric Primary Glomerulopathies

FOXP3+ regulatory T-cell (Tregs) detection in renal allograft biopsies has been associated with a less intense immune response. Data about FOXP3+ Tregs’ presence and role in primary glomerulopathies of native kidneys are minimal. We comparatively studied the immunohistochemical expression of FOXP3+ Tregs, CD4+ and CD3+ T cells in IgA nephropathy (IgAN), focal segmental glomerulosclerosis (FSGS), and membranous glomerulopathy (MGN). We retrospectively reviewed 71 renal biopsies (28 from patients with IgAN, 22 from patients with FSGS and 21 from patients with MGN) performed with proteinuria as the main indication. FOXP3+ Tregs and CD4+ and CD3+ T cells in inflammatory cell infiltrates of the interstitial tissue and periglomerular space were automatically counted using image analysis software. Univariable and multivariable logistic regressions were applied for statistical analysis. Nuclear FOXP3+ immunohistochemical expression was observed in T cells in 64% of IgAN cases, 77% of FSGS cases, and 76% of MGN cases ( p > 0.05 ). Absolute FOXP3+ Tregs count in the interstitial tissue was higher in patients without arteriolar hyalinosis than in those with arteriolar hyalinosis (1.814 ± 2.160 vs. 831 ± 696; p = 0.029 ). In patients with a high FOXP3+/CD4+ ratio in the interstitial tissue, the odds ratio for CKD-EPI eGFR ≥60 ml/min/1.73 m2 at biopsy was 4.80 (95% CI: 1.29–17.91; p = 0.019 ). FOXP3+ Tregs intrarenal infiltration in primary glomerulopathies is common. FOXP3+ Tregs’ increased expression may be associated with milder histological lesions. High FOXP3+/CD4+ ratio in the interstitial tissue may have prognostic significance for renal function preservation.

MO646PATHOLOGICAL PROGNOSTIC FACTORS IN DIABETIC NEPHROPATHY: A RETROSPECTIVE STUDY

Background and Aims Kidney Biopsies (KB) performed in patients with Type-2 diabetes (T2D) usually aim at differentiating diabetic nephropathy (DN) from other kidney diseases. However, KB could also help refining patients’ prognosis, both in terms of renal survival, and in terms of patient survival. In 2010, the Renal Pathology Society developed a pathological classification of DN, but the prognostic value of the described items , is still imperfectly documented. We aimed to assess the prognostic performances of these items to predict renal and patient survival. Method Native KBs with diabetic and/or hypertensive nephropathy (DN/HN) performed in patients with T2D in four French centers were analyzed and scored according to the classification developed by the Renal Pathology Society. Clinical and biological data was collected from the patients’ records. Survival analyses were performed for renal survival (time to first dialysis or preemptive transplantation) and death after dichotomization of continuous data). For each of the analyses, we first established a model comprising clinical data only. We then assessed the benefit of adding each of the pathological item to the clinical model. Finally, we performed a backward stepwise analysis to identify items predictive of renal and/or patient survival. Results We analyzed 165 biopsies with DN/HN from patients with T2D and with at least 12 months of follow-up (unless they reached an endpoint during the first year). Among them, 73 (44%) were male, 155 (94%) had hypertension, 53 (34%) hematuria, 22 (15%) had proliferative diabetic retinopathy (DR), 33 (23%) had non-proliferative DR, 90 (62%) had no DR (20 had missing data). Mean (SD) age was 63 (11), median [IQR] eGFRCKD-EPI was 29 [18;45] ml/min/1.73m², urinary protein-to-creatinine ratio was 0.38 [0.14;0.83] g/mmol, HbA1c was 7 [6.2;8.2] % and diabetes duration before KB was 10 [5;19] years. The median [IQR] follow-up was 33 months[18;57]. During the follow-up, 43 (26%) patients died and 69 (42%) required renal replacement therapy (RRT). The percentage of ischemic glomeruli, and presence of more than one area of arteriolar hyalinosis (ah=2), were predictive of renal survival and improved the predictive value of the model when added to clinical parameters. Presence of at least one convincing Kimmelstiel–Wilson lesion (nodular glomerulosclerosis or Class III DN) was predictive of death and similarly improved the predictive model (See figure). Conclusion Pathological findings on KB, as classified by the Renal Pathology Society, carry significant prognostic value in patients with T2D and DN/HN. Vascular lesions (presence of arteriolar hyalinosis and less than 7% of ischemic glomeruli) predicted the need for RRT, while nodular glomerulosclerosis was predictive of death.

Steroid Resistant Focal Segmental Glomerulosclerosis: Effect of Arterial Hyalinosis on Outcome: Single center study

Background: Few data with adequate evidence exists regards the effect of Cyclosporine (CsA) and mycophenolate mofetil (MMF) on pathological prognostic parameters in patients with steroid resistant focal segmental glomerulosclerosis (FSGS). The purpose of the present study is to compare the effect of cyclosporin and mycophenolate mofetil in addition to steroids on functional and histopathologic renal parameters in patients with steroid resistant FSGS one year after treatment.Material and methods: Thirty-seven adults with primary FSGS patients resistant to steroid therapy consecutively randomized to treatment with either MMF or cyclosporine. Low dose prednisolone added to both groups. Glomerular filtration rate (GFR) and blood pressure (BP) were determined at all examinations and a second renal biopsy was taken 12 months after treatment with either of cyclosporin and mycophenolate mofetil.Results: GFR significantly increased in MMF group p <0.01 after 6 months and unchanged after 12 months. On the other hand, GFR significantly decrease in CsA group p <0.001 after 6 months and reduced more after 12 months p <0.001 compared to base line levels. Significant difference of GFR between the 2 groups at 6 months p<0.001. The extent of proteinuria decreased significantly in CsA group after 12 months p <0.001. The extent of arteriolar hyalinosis increased significantly in CsA group (0.78 to 1.81 score, p <0.001) but was unchanged in MMF group (0.93 to 0.96 score), whereas interstitial fibrosis increased to same level in both groups (grade 3).Conclusion: Conversion to MMF in those patients may be superior to CsA as regard GFR after 12 months after treatment in spite presence of greater level of protein excretion. The increased arteriolar hyalinosis during CsA treatment most likely result in higher BP compared to MMF treatment in patients with FSGS resistant to steroids.

High Blood Pressure Is Associated with Tubulointerstitial Damage along with Glomerular Damage in Glomerulonephritis. A large Cohort Study

The key role of arterial hypertension in chonic kidney disease (CKD) progression is widely recognized, but its contribution to tubulointerstitial damage (TID) in glomerulonephritis (GN) remains uncertain. Hence, the objective of this study is to clarify whether TID is associated with glomerular damage, and whether the damage at the tubulointerstitial compartment is more severe in hypertensive patients. The study included retrospectively consecutive patients referred to the Nephrology Unit with diagnoses of primary glomerulonephritis, lupus nephritis (LN), and nephroangiosclerosis (NAS) at biopsy. At least six glomeruli per biopsy were analysed through light and immunofluorescence microscopy. Global glomerulosclerosis (GGS%), TID, and arteriolar hyalinosis (AH) were used as markers of CKD severity. Of the 448 patients of the cohort, 403 received a diagnosis of GN, with the remaining being diagnosed with NAS. Hypertension was found in 52% of the overall patients, with no significant differences among those with GN, and reaching 88.9% prevalence rate in NAS. The hypertensive patients with GN had more marked damage in glomerular and tubular compartments than normotensives independently of the amount of proteinuria. Moreover, hypertension and GGS% were found to be strongly associated with TID in GN. In GN patients, not only the severity of glomerular damage but also the extent of TID was associated with high blood pressure.

Characteristic Renal Histology of a 81-Year-Old Patient with a 30-Year History of Diabetes Mellitus: A Case Report

A renal histology of an 81-year-old man with a 30-year history of diabetes mellitus (DM), as well as diabetic retinopathy and neuropathy, was examined. The patient’s blood pressure was controlled within the normal range (less than 140/75 mmHg) using antihypertensive agents including angiotensin receptor blocker. Edematous management was achieved by a strict salt diet (less than 6 g/per day). However, this patient’s glycemic control was poor with HbA1c 8–10%. Serum creatinine was 0.87 mg/dL and estimated globular filtration rate (eGFR) was 64 ml/min/1.73m2. Urinary protein excretion was 1.5 g/day. This patient’s renal biopsy showed linear staining for IgG along the GBM by immunofluorescence microscopy, but light microscopy showed almost intact glomeruli, and the GBM was not thickened as revealed by electron microscopy with a width of 288–368 nm (< 430 nm). While arteriolar hyalinosis was severe, and polar vasculosis was observed around the glomerular vascular pole. This case indicates that long-standing hyperglycemia may induce polar vasculosis by the mechanism of angiogenesis, but diabetic glomerulopathy can become minor change, only when hypertension and edematous management could be controlled strictly.

Kidney Structural Features from Living Donors Predict Graft Failure in the Recipient

BackgroundNephrosclerosis, nephron size, and nephron number vary among kidneys transplanted from living donors. However, whether these structural features predict kidney transplant recipient outcomes is unclear.MethodsOur study used computed tomography (CT) and implantation biopsy to investigate donated kidney features as predictors of death-censored graft failure at three transplant centers participating in the Aging Kidney Anatomy study. We used global glomerulosclerosis, interstitial fibrosis/tubular atrophy, artery luminal stenosis, and arteriolar hyalinosis to measure nephrosclerosis; mean glomerular volume, cortex volume per glomerulus, and mean cross-sectional tubular area to measure nephron size; and calculations from CT cortical volume and glomerular density on biopsy to assess nephron number. We also determined the death-censored risk of graft failure with each structural feature after adjusting for the predictive clinical characteristics of donor and recipient.ResultsThe analysis involved 2293 donor-recipient pairs. Mean recipient follow-up was 6.3 years, during which 287 death-censored graft failures and 424 deaths occurred. Factors that predicted death-censored graft failure independent of both donor and recipient clinical characteristics included interstitial fibrosis/tubular atrophy, larger cortical nephron size (but not nephron number), and smaller medullary volume. In a subset with 12 biopsy section slides, arteriolar hyalinosis also predicted death-censored graft failure.ConclusionsSubclinical nephrosclerosis, larger cortical nephron size, and smaller medullary volume in healthy donors modestly predict death-censored graft failure in the recipient, independent of donor or recipient clinical characteristics. These findings provide insights into a graft’s “intrinsic quality” at the time of donation, and further support the use of intraoperative biopsies to identify kidney grafts that are at higher risk for failure.