M. Dinic

BACKGROUND: Doppler-based renal resistive index (RI) calculation may help in the early detection of acute kidney injury (AKI). Its feasibility and reproducibility by inexperienced operators remain unknown. The main objective of this study was to compare performances of junior and senior operators in assessing renal perfusion using both the semiquantitative color-Doppler scale and RI calculation. METHODS: Prospective cohort study performed in 3 ICUs. Inexperienced juniors physicians attended a half-day course on renal perfusion assessment using RI calculation and color-Doppler (from 0, absence of renal perfusion; to 3, renal vessels identifiable in the entire field of view). Junior and senior operators used both methods in 69 mechanically ventilated patients, in blind fashion. RESULTS: Failure to obtain RI occurred for a junior operator in a single patient. RI and color-Doppler semi-quantitative values obtained by operators were correlated (r²=0.64 and r²=0.61, respectively). Systematic bias across operators as assessed using Bland-Altman plots was negligible (-0.001 and -0.29, respectively), although precision was limited (95% confidence intervals, +0.105 to -0.107 and +0.98 to -1.04, respectively). RI calculation and semi-quantitative assessment performed well for diagnosing persistent AKI (area under the receiver-operating characteristic curve, 0.84 [95% confidence interval, 0.73-0.97] and 0.87 [0.77-0.97], respectively). CONCLUSION: A brief course on renal Doppler allowed inexperienced operators to assess effectively renal perfusion with a good reliability when compared to senior operators. In addition, our results suggest the good diagnostic performance of both Doppler-based RI and semi-quantitative renal perfusion assessment in predicting short-term renal dysfunction reversibility.

Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell–mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium. Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell–mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium.

Export Activation of complement through the alternative pathway has a key role in the pathogenesis of IgA nephropathy (IgAN). Large, international, genome-wide association studies have shown that deletion of complement factor H–related genes 1 and 3 (CFHR3,1Δ) is associated with a reduced risk of developing IgAN, although the prognostic value of these deletions in IgAN remains unknown. Here, we compared the renal outcomes of patients with IgAN according to their CFHR3,1Δ genotype. This retrospective, monocentric cohort study included 639 white patients with biopsy-proven IgAN since 1979 (mean age at diagnosis, 40.1 years; median follow-up, 132 months). We determined the number of CFHR3 and CFHR1 gene copies by quantitative PCR and collected clinical and biologic data by reviewing the patients’ medical records. In all, 30.5% of the patients were heterozygous and 4% were homozygous for CFHR3,1Δ. We did not detect an association between CFHR3,1Δ and age, eGFR, urinary protein excretion rate, or the presence of hypertension or hematuria at the time of diagnosis. The mean intensities of immune IgA, IgG, and C3 deposits were lower in the group with heterozygous or homozygous gene deletions than in those with no deletion. However, CFHR3,1Δ did not associate with progression to stage 3 CKD or renal death. In conclusion, the CFHR3,1Δ genotype did not associate with progression toward CKD stages 3 and 5 in our white population of patients with IgAN, although it did associate with a reduced level of glomerular immune deposits.

The effect of renal artery angioplasty on blood pressure in patients with true resistant hypertension and atherosclerotic renal artery stenosis has not been fully investigated due to the exclusion of these patients from most trials. In this study, we assessed the benefits of renal angioplasty on daytime ambulatory blood pressure (dABP) in this subgroup of patients. Medical records of our hypertension department were retrospectively analyzed from 2000 to 2016. Seventy-two patients were identified with resistant hypertension (dABP >135 or 85 mm Hg despite at least 3 antihypertensive drugs, including a diuretic) and atherosclerotic renal artery stenosis treated by angioplasty. Atherosclerotic renal artery stenosis was unilateral in 57 patients and bilateral in 15 patients. The mean age of the patients was 67.8±11.2 years; dABP was 157±16/82±10 mm Hg despite 4.0±1.0 antihypertensive treatments; estimated glomerular filtration rate was 52 (41–63) mL/min. After renal angioplasty, dABPM decreased by 14.0±17.3/6.4±8.7 mm Hg ( P <0.001 for both), and the number of antihypertensive treatments decreased to 3.6±1.4 ( P =0.002) with no significant change in estimated glomerular filtration rate. A high baseline systolic dABP and a low body mass index were independent predictors of systolic dABP changes. The decrease in dABP was confirmed in a subgroup of patients at one and 3 years of follow-up (N=31 and N=18 respectively, P ≤0.001 for systolic and diastolic blood pressure at both visits). In this retrospective uncontrolled single-center study, angioplasty in patients with atherosclerotic renal artery stenosis and with true resistant hypertension significantly decreased dABP, reducing the need for antihypertensive treatment with no change in estimated glomerular filtration rate.

BACKGROUND: The prognosis of IgA nephropathy (IgAN) is very heterogeneous. Predicting the nature and the rate of the disease progression is crucial for refining patient treatment. The aim of this study was to evaluate the prognostic impact of an Oxford classification-based repeat kidney tissue evaluation to predict end-stage renal disease (ESRD). METHODS: Patients with biopsy-proven primary IgAN who underwent two renal biopsies at our centre were analyzed retrospectively. Renal biopsies were scored by two pathologists blinded to the clinical data and according to the updated Oxford classification. Cox models were generated to evaluate the prognostic impact considering the Oxford classification elementary lesions from the first (Model 1) or the second (Model 2) biopsy, adjusted on clinical data at time of reevaluation. The prognostic impacts of the dynamic evolution of each elementary lesion between biopsies were also assessed through univariate and multivariate evaluation. RESULTS: A total of 168 adult patients were included, with a median follow-up duration of 18 (range 11-24) years. The second biopsy was performed either systematically (n = 112) of for-cause (n = 56), after a median time of 5.4 years. The prognostic performances of Model 2 (second biopsy) were significantly better than Model 1 (first biopsy, analysis of deviance P < 0.0001). The dynamic changes of C and T lesions were significantly associated with the progression toward ESRD after adjustment on variables from Model 2. CONCLUSION: Both static and dynamic Oxford-based histological evaluation offered by a repeat biopsy improves the prediction of ESRD in patients with IgAN.