Shorter observation times and smaller gauge needles in outpatient kidney biopsies.

Controversy exists as to the optimal observational time (OT) after outpatient percutaneous kidney biopsy. Further, there is some uncertainty about the benefit of smaller (18-gauge) vs. larger (16-gauge) biopsy needles. At our institution, we have been lowering the OT after outpatient kidney biopsies. Initially in 2015, we were monitoring for 6 hours and gradually began to decrease the OT over time. From 2020, we have adopted an OT of less than 4 hours. During this time period (in 2018), we also began using a smaller gauge needle (18 gauge). We reviewed all outpatient kidney biopsies performed by the nephrology division at our institution since 2015. There were 137 biopsies reviewed. 63 had OT of 4 - 6 hours, and 74 had OT < 4 hours. There was a total of 4 significant complications (2.9%). Two complications, symptomatic retroperitoneal bleeds, were detected in less than 3 hours. The other 2 complications were seen at 9 hours (clot retention) and 72 hours (retroperitoneal bleed after anticoagulation restarted). 63% of the biopsies were done using 18-gauge needles with 1 complication in this group vs. 3 in the 16-gauge group. All cases had adequate tissue for interpretation based on the ability to make a kidney diagnosis. The number of glomeruli obtained in the 18-gauge group was 29 ± 13 glomeruli, and in the 16-gauge group was 25 ± 10, which did not differ between groups. In summary, in an outpatient population, all significant post-biopsy complications were evident either within the first 3 hours or after 9 hours, and this suggests the feasibility of using shorter than standard OT in outpatient kidney biopsies. Furthermore, an 18-gauge needle may lower the risk of complications and obtain adequate tissue.

Implication of acute tubular injury in minimal change nephrotic syndrome.

While acute tubular injury (ATI) is known to occur in a significant number of minimal change disease (MCD) nephrotic syndrome cases with acute kidney injury (AKI), the clinical significance is not certain, and AKI may also occur without ATI. This study aimed to evaluate whether the severity of AKI defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria correlated with the presence or severity of ATI in a series of adult patients with MCD. We also looked at whether time to remission of nephrotic syndrome (NS) with treatment correlated with the presence of ATI in those with and without AKI. We excluded patients with secondary MCD. Of 61 patients, 20 had AKI (33%). ATI was significantly more likely to occur in those with AKI than in those without AKI (60 vs. 24%). Overall, the severity of AKI did not clearly correspond with the severity of ATI. Remission rates at 4 weeks were lowest (25%) in those with both AKI and ATI, while they were highest (100%) in those with neither AKI nor ATI. Patients with AKI but no ATI and those with no AKI but having ATI were intermediate in remission rates and similar to each other (60 and 62%, respectively). The time to remission in the group of those without AKI was significantly longer in those with ATI than in those without (p = 0.0027), but the numerical difference in remission did not reach statistical significance in the smaller group of AKI patients. Patients with ATI were older and more often male than those without ATI. It appears that having ATI may predict a slower remission rate in MCD though the reason for this is unclear. The different demographics of those with ATI may also play a role.

Oxalate nephropathy: a review.

This review describes the clinical and pathological features of oxalate nephropathy (ON), defined as a syndrome of decreased renal function associated with deposition of calcium oxalate crystals in kidney tubules. We review the different causes of hyperoxaluria, including primary hyperoxaluria, enteric hyperoxaluria and ingestion-related hyperoxaluria. Recent case series of biopsy-proven ON are reviewed in detail, as well as the implications of these series. The possibility of antibiotic use predisposing to ON is discussed. Therapies for hyperoxaluria and ON are reviewed with an emphasis on newer treatments available and in development. Promising research avenues to explore in this area are discussed.

Adult primary nephrotic syndrome trends by race: a diminished frequency of focal segmental glomerulosclerosis in non-black patients.

PURPOSE: There have been conflicting data on the relative frequency of common forms of primary nephrotic syndrome (PNS). We undertook this study to look at the causes of PNS in the latest decade from our biopsy population, with a special attention to breakdown by race. METHODS: Retrospective chart review of all cases of adult PNS extracted from a database of 1388 cases for the last 10 years. We were careful to exclude patients with secondary disease and without the full nephrotic syndrome. RESULTS: There were 115 cases of PNS. Overall, MN was the most common lesion (40.0%), followed by minimal change disease (MCD) (34.0%), focal segmental glomerulosclerosis (FSGS) (13.0%), and IgA nephropathy (IgAN) (11.3%). Among whites, MN was the most common cause of NS (41.7%), followed by MCD (33.3%), IgAN (16.7%), and FSGS (6.3%). Among blacks, FSGS was the most common lesion (33.3%) followed closely by MN (29.6%), and MCD (26.0%). IgAN was present in 7.4%. Among multiracial patients (MR), MGN was the most common (50%) followed by MCD (45.5%) and FSGS (4.5%). In Asians, MCD (50.1%) and MGN (33.3%) were the most common, followed by FSGS and IgAN with 8.3% each. CONCLUSIONS: MN and MCD were the most common causes of PNS in our population, with FSGS much less common overall. This is especially the case among whites and MR. Among blacks, MN and FSGS were almost codominant causes. The apparent decreased prevalence of FSGS may be related to more effective exclusion of secondary and maladaptive causes.

Novel Approaches to Arteriovenous Access Creation, Maturation, Suitability, and Durability for Dialysis.

Since the arteriovenous fistula (AVF) was first conceived over 50 years ago, the goal to create a vascular conduit with predictable and reproducible maturation and durability continues to elude caregivers. Recently, however, advances in the understanding of vascular biology and new technologies now provides us with some optimism; we are moving toward a viable solution. A quickly maturing, sustainable, and durable arteriovenous access may soon be attainable. This review will discuss these advances. There are novel approaches to AVF creation and devices to enhance maturation, advances in arteriovenous graft material(s), and devices to safely prolong the use of tunneled dialysis catheters. Although hemodialysis (HD) access remains a complex problem, these innovations may lead the way to optimizing the care and the quality of life of those patients who have no choice but to proceed with HD.

Use of lung ultrasonography to determine the accuracy of clinically estimated dry weight in chronic hemodialysis patients.

PURPOSE: The use of lung ultrasound (LUS) to identify extravascular lung water has received increasing acceptance. Sonographic B-lines, discrete vertical lines that originate from the pleura, represent pulmonary edema and are correlated with the accumulation of fluid. The goal of this study was to evaluate the utility of LUS to determine the accuracy of prescribed dry weight (DW) in chronic hemodialysis (HD) patients and to ascertain the adequacy of fluid removal. METHODS: LUS was scheduled to be performed pre- and post-HD in 20 patients. The HD prescription and DW challenge were done independent of the results of the LUS. The presence of B-lines was tabulated and compared to the intradialytic ultrafiltration parameters. RESULTS: Of the 20 patients, 3 did not exhibit B-lines at the first dialysis session. In regard to the other 17 patients, B-lines disappeared in 7 patients at the end of the HD session (mean B-lines 4.2-0). One patient was 0.3 kg away from the prescribed dry weight, but the 6 patients were a mean of 1.7 kg below DW. Of the remaining 10 patients, eight decreased but did not eliminate the B-lines (mean B-lines 15.5-3.8) and were a mean of 3.8 kg below DW post-HD. Two patients who exhibited more cardiac insufficiency than initially recognized could not reach DW or eliminate the B-lines. Eight patients who had residual B-lines at the end of the first HD session had their DW re-estimated and had a second session. Two were able to eliminate the B-lines (mean 2.5-0) and reached a mean of 1.2 kg below DW. Six did not eliminate the B-lines (mean 11.5-4.2) but were able to reach a mean of 0.6 kg below DW. Correlation analysis showed a statistically significant correlation (P < 0.05) between the intradialytic percent change in B-lines and the percent change in total body weight (r = 0.40) and ultrafiltration rate (r = 0.33). Seven of 10 patients with clear chest X-rays pre-HD exhibited B-lines. CONCLUSIONS: This study supports the hypothesis that reduction in B-lines during HD can provide accurate information regarding changes in pulmonary fluid content. Further, LUS is a valuable diagnostic tool for recognizing both the adequacy of fluid removal and the occurrence of error in the estimation of dry weight by usual clinical parameters.

Epidemiology and Challenges to the Management of Advanced CKD.

Advanced CKD is a period of CKD that differs greatly from earlier stages of CKD in terms of treatment goals. Treatment during this period presents particular challenges as further loss of kidney function heralds the need for renal replacement therapy. Successful management during this period increases the likelihood of improved transitions to ESRD. However, there are substantial barriers to optimal advanced CKD care. In this review, we will discuss advanced CKD definitions and epidemiology and outcomes.

Oral vitamin C supplementation reduces erythropoietin requirement in hemodialysis patients with functional iron deficiency.

PURPOSE: Functional iron deficiency (FID) is a major cause of persistent anemia in dialysis patients and also contributes to a suboptimal response to erythropoietin (Epo) administration. Vitamin C acts as an enzyme cofactor and enhances mobilization of the ferrous form of iron to transferrin thus increasing its bioavailability. High-dose intravenous vitamin C has been shown to decrease the Epo requirement and improve hemoglobin levels in previous studies. This study assessed the effect of low-dose oral vitamin C on possible reduction in Epo dose requirements in stable hemodialysis patients with FID. METHODS: This prospective study included 22 stable hemodialysis patients with FID defined as transferrin saturation (T sat) <30 % and ferritin levels of >100 mcg/L with Epo requirement of ≥4000 U/HD session. Patients received oral vitamin C 250 mg daily for 3 months. Hemoglobin, iron and T sat levels were recorded monthly. No one received iron supplementation during the study period. RESULTS: There was a significant reduction in median Epo dose requirement in the 15 patients who completed the study, from 203.1 U/kg/week (95 % CI 188.4-270.6) to 172.8 U/kg/week (95 % CI 160.2-214.8), (P = 0.01). In the seven responders, there was 33 % reduction in Epo dose from their baseline. Despite adjustment of Epo dose, the mean hemoglobin level was significantly increased from 10.1 ± 0.6 to 10.7 ± 0.6 mg/dL (P = 0.03). No adverse effects of oral vitamin C were observed. CONCLUSION: Daily low-dose oral vitamin C supplementation reduced Epo dose requirements in hemodialysis patients with FID. Limitations of this study include a small sample size and the lack of measurements of vitamin C and oxalate levels. Despite concerns regarding oral vitamin C absorption in dialysis patients, this study indicates vitamin C was well tolerated by all participants without reported adverse effect.

A review of the nonpressor and nonantidiuretic actions of the hormone vasopressin.

The pressor and antidiuretic actions of arginine vasopressin (AVP) have been well documented. This review focuses on the less widely appreciated actions of AVP which also have important physiologic functions and when better understood may provide important insights into common disease states. These actions include effects on pain perception and bone structure as well as important relationships to the varied components of metabolic syndrome. These include effects on blood glucose, lipid levels, and blood pressure. AVP may also play a role in the progression of chronic kidney disease and effect physiologic changes relating to aging, abnormal social behavior, and cognitive function. Important cellular responses including cell proliferation, inflammation, and control of infection and their relationship to AVP are described. Finally, the effects of AVP on hemostasis and the hypothalamic-pituitary-adrenal axis are noted. The goal of this summary of the various actions of AVP is to direct attention to the potential benefits of research in these underemphasized areas of importance.

Mycophenolate mofetil as a steroid-sparing agent in sarcoid-associated renal disease.

Steroids are the mainstay of treatment for renal sarcoidosis. Many patients with sarcoidosis are chronically dependent on steroids and there is limited data on the use of steroid-sparing agents. This is a case of a patient that has remained in remission using mycophenolate mofetil (MMF) as a steroid-sparing agent. The patient is a 56-year-old female with a history of sarcoidosis diagnosed by lymph node biopsy who developed 3 episodes of acute kidney injury (AKI) in the setting of exacerbations of her sarcoidosis, each responding to prednisone treatment. Due to possible lifelong need for prednisone, MMF was started as a steroid-sparing treatment. She tolerated the MMF well and has now been steroidfree for 22 months. There have been only a few case reports about the use of MMF as a steroid-sparing agent in sarcoid-associated renal disease, in which patients could be successfully weaned off steroids. This is the longest reported follow-up of a patient being off steroids while on MMF. It is also notable for the patient having a relapse on the MMF which responded to an increased dose. MMF should be studied further as a potential steroid-sparing agent in the treatment of sarcoid associated renal disease.

Preventing the progression of chronic kidney disease: two case reports and review of the literature.

A variety of therapeutic modalities are available to alter the abnormalities seen in patients with chronic kidney disease (CKD). A comprehensive plan can now be developed to slow the progression of CKD. Two clinical cases of delay in the need for renal replacement therapy are described. This delay was achieved by using recognized recommendations for optimal diabetes therapy (HbA1c target 7 %), goals for blood pressure levels, reduction of proteinuria, and the proper use of ACEI/ARB therapies. Recent recommendations include BP <140/90 mmHg for patients <60 years old and <150/90 mmHg for older patients unless they have CKD or diabetes. Limits on dietary sodium and protein intake and body weight reduction will decrease proteinuria. Proper treatment for elevated serum phosphorous and parathyroid hormone levels is now appreciated as well as the benefits of therapy for dyslipidemias and anemia. Concerns regarding unfavorable outcomes with excess ESA therapy have led to hemoglobin goals in the 10-12 g/dL range. Finally, new therapeutic considerations for the treatment of acidosis and hyperuricemia are presented with data available to suggest that increasing serum bicarbonate to >22 mmol/L is beneficial, while serum uric acid therapeutic goals are still uncertain. Also, two as yet insufficiently understood approaches to altering the course of CKD (FGF-23 level reduction and balancing gut microbiota) are noted.

Characteristics, therapies, and factors influencing outcomes of hospitalized hypernatremic geriatric patients.

PURPOSE: Hypernatremia is a common electrolyte disorder associated with adverse outcomes such as increased length of stay and mortality due to a variety of factors. Our aim was to investigate known factors as well as other variables which we had identified in hospitalized hypernatremic geriatric patients and their relationship to patient outcomes. METHODS: A retrospective chart review of all adult hospitalized patients in a 4-month period with a serum sodium level >150 mmol/L was performed. Factors evaluated included use of a nephrology consultation, certain urine laboratory measures, fluids employed, rate of correction, and patient's level of care setting. Outcome measures included length of stay and mortality. RESULTS: The patient mortality rate was 52 %. Mean age was 79.6 years (n = 33), and mean initial sodium level was 152.6 mmol/L. Plasma and urine osmolality, and urine sodium concentration were checked in less than 25 % of patients. Fifteen of 18 patients in the ICU expired, whereas only 2 of 15 patients not in the ICU expired (p < 0.0004, OR 32.50, CI 95 % (4.68-225.54)). Of the 23 patients (70 %) who had their serum sodium level corrected, 11 were corrected in ≤3 days and 12 in >3 days, but this difference did not affect mortality rate (45 vs. 50 %, p = 0.99). The mortality rate was similar (60 %, p = 0.52) for those whose serum sodium level never corrected suggesting that correction did not influence outcomes. The fluids chosen for therapy of the hypernatremia were appropriate to the patients volume status. Five of 15 patients who received a nephrology consultation survived, while 11 of 18 patients without a nephrology consultation survived (p = 0.12). The mean length of stay was 25.0 ± 23.9 days and no different for those who expired versus those who survived (25.2 ± 21.2 vs. 24.8 ± 25.9 days, p = 0.96). CONCLUSIONS: Hypernatremia is associated with a poor prognosis, and outcomes are still disappointing despite appropriate rates of correction, intensive monitoring, and the involvement of a nephrologist. Strategies directed at avoidance of the development of hypernatremia and attention to concomitant disease may provide significant patient benefit.

Neurofibromatosis type 1-associated hypertension secondary to coarctation of the thoracic aorta.

Neurofibromatosis type 1 (NF-1), also known as von Recklinghausen's disease, is an autosomal dominant genetic disorder. NF-I vasculopathy has been used to describe various vascular malformations associated with NF-1. Secondary hypertension related to NF-1 vasculopathy has been reported because of renal artery stenosis, coarctation of the abdominal aorta and other vascular lesions; however, coarctation of the thoracic aorta has seldom been reported. We report the first case, to our knowledge, of isolated coarctation of thoracic aorta in a pregnant female with NF-1. Healthcare providers caring for patients with NF-1 should be aware of associated vascular complications.

Massive intravascular hemolysis with mechanical rheolytic thrombectomy of a hemodialysis arteriovenous fistula.

A 57-year-old man with chronic kidney disease stage 5 presented for ambulatory evaluation of his arteriovenous fistula. He underwent rheolytic thrombectomy with tissue plasminogen activator infusion, angioplasty, and brachial artery stenting under local sedation. His immediate postoperative course was complicated by hypotension, cardiac dysrhythmias and hyperkalemia requiring emergent hemodialysis, due to severe intravascular hemolysis. This case illustrates that mechanical thrombectomy can cause clinically significant intravascular hemolysis, thus careful postoperative monitoring is recommended.

Cytomegalovirus-induced collapsing focal segmental glomerulosclerosis.

Collapsing glomerulopathy is an aggressive morphologic variant of focal segmental glomerulosclerosis which typically presents with nephrotic syndrome and rapidly progressive renal failure. Most cases of collapsing glomerulopathy are associated with human immunodeficiency virus infection. We present a rare case of collapsing glomerulopathy associated with acute cytomegalovirus (CMV) infection in an immunocompetent host with improvement in renal function after the treatment of CMV with ganciclovir. CMV may be an under-recognized cause of collapsing glomerulopathy which may respond to antiviral treatment.

Troponin I as a prognostic marker of cardiac events in asymptomatic hemodialysis patients using a sensitive troponin I assay.

Elevated troponin T is known to be a prognostic marker for long-term cardiac events and mortality in asymptomatic end-stage renal disease patients. There are conflicting data in this regard with respect to troponin I (TnI). We recently showed a high incidence of elevated TnI levels in asymptomatic hemodialysis (HD) patients using a new generation sensitive TnI assay. The aim of this pilot study was to explore the prognostic value of TnI, as measured with this new assay, as a marker for outcomes in HD patients over a 2-year follow-up period. Fifty-one asymptomatic HD patients were enrolled, and pre-dialysis TnI levels were checked once monthly over 3 consecutive months. Patients were considered to be in the TnI positive group if TnI level on any of the three draws was ≥0.035 ng/ml. All patients were followed for a period of 2 years. The primary end points were acute coronary syndrome, coronary revascularization, sudden death, or cardiac arrest. The secondary end point was all-cause mortality. Elevated TnI levels were found in 51% (26/51) of patients in our cohort. One TnI positive patient was subsequently lost to follow up. There were 6 cardiac events over 2 years, all of which were in the troponin positive group (6/25 or 24%). The presence of a positive TnI at baseline was significantly associated with future cardiac events (p=0.022). A prior history of coronary artery disease (CAD) was also significantly related to future cardiac events (p=0.010). No patient with negative TnI at baseline developed a cardiac event, while 45.5% of those with both a positive TnI and a history of CAD had an event. Fourteen deaths occurred over 2 years, 8 in TnI positive and 6 in the negative group. All-cause mortality was not associated with elevated TnI levels at baseline. We found a significant association between positive TnI and subsequent cardiac events in asymptomatic HD patients followed for 2 years. TnI levels, as measured with a sensitive assay, may be useful in assessing cardiac risk in asymptomatic HD patients. This needs further confirmation in a larger cohort.