Idiopathic Nonviral Cryoglobulinemia Treated Successfully With Rituximab.

Cryoglobulinemia is a systemic inflammatory syndrome that generally involves small-to-medium vessel vasculitis due to cryoglobulin-containing immune complexes. The therapeutic management of idiopathic cryoglobulinemic vasculitis has yet to be defined because no study has evaluated the best strategies. However, treatment of severe vasculitis is traditionally based on a combination of corticosteroids and immunosuppressants or plasmapheresis, and more recently rituximab. We report a case of 77-year-old female patient diagnosed with idiopathic cryoglobulinemia, treated successfully with 6 months prednisone tapering and 2 doses of rituximab (1 g each dose). After receiving the above-mentioned treatment, her creatinine went back to normal with resolution of proteinuria and hematuria, normalization of serum complements, and significant improvement in her clinical picture. We conclude that rituximab could be an effective treatment for idiopathic cryoglobulnemia.

Ipilimumab granulomatous interstitial nephritis.

Drug-induced interstitial nephritis is a recognized cause of acute and chronic renal failure. Some of them lead to the formation of granulomata. T-cell-mediated immune response is implicated in the pathogenesis. Here, we describe the case of a 74-year-old male patient with metastatic melanoma who was referred to our clinic with a history of rash and worsening renal function. Because of subacute onset, progressively worsening renal function in the presence of skin rash, elevated liver enzymes, and in the background of exposure, medication-induced interstitial nephritis was suspected. He received 3 doses of ipilimumab, a novel drug used in the treatment of metastatic melanoma within 3 months before the onset of renal failure. A renal biopsy was done, which showed granulomatous interstitial nephritis. Renal biopsy findings, temporal relation between renal failure and exposure to medication, and review of the literature supported a diagnosis of ipilimumab-induced renal failure. He was started on steroids, and renal function recovered in the next 1 month. Immune-related adverse reaction is one of the common side effects of ipilimumab. Ipilimumab-induced hepatitis and colitis has been previously reported in the literature. This is the first ever case report of ipilimumab-induced granulomatous interstitial nephritis.

Outcomes of Transplantation of Single Kidneys From Pediatric Donors Into Adult Recipients.

Background Organs from extreme ages have been sought after to help increase the donor pool and alleviate transplantation wait times. There has been a growing evolution of the use of pediatric donor kidneys, including the use of en bloc kidneys (EBK), to now separating them into single kidneys (SKT), allowing for transplantation of two recipients. This study reports our outcomes utilizing SKT. Methods A retrospective review of all SKT performed from 2014 to 2022 at our center was conducted. Donors >8 years of age or >25 kg in weight were excluded. Donor and recipient characteristics and outcomes were analyzed, comparing <18 kg and ≥18 kg donor cohorts. Results Between 2014 and 2022, 81 adults received SKT. Recipients' mean age, weight, and body mass index were 49 years (22-74), 74 kg (39-136), and 26.4 mg/m2 (19.6- 39.8), respectively. Donors' mean age, weight, and kidney size were 35.7 months (8-96), 17.8 kg (8-25), and 7.2 cm (4.5-8.5), respectively. At one year post-transplant, patient survival was 100%, graft survival was 98.7%, mean serum creatinine was 1.25 mg/dL, and mean glomerular filtration rate (GFR) was 68.3 ml/min. Hyperfiltration injury was seen in 43.75% of recipients. None of the outcomes correlated with any of the donor or recipient characteristics. Conclusion Our study shows excellent short-term outcomes of single pediatric kidney transplantation in adult recipients. Exploring a lower donor weight cut-off for SKT, compared to the current Organ Procurement and Transplantation Network's (OPTN's) ≥18 kg, could expand the organ pool and lead to an increased number of transplants.

"Pre-Histologic" Antibody-Mediated Rejection Detected by Donor-Derived Cell-Free DNA and a Novel Tissue Gene Expression Assay: A Case Report.

BACKGROUND: Despite its well-characterized association with poor long-term graft outcomes, subclinical antibody-mediated rejection (ABMR) in recipients of kidney transplants continues to pose a significant diagnostic and therapeutic challenge. Specifically, its detection currently relies on invasive histologic surveillance, a relatively uncommon practice among US transplant centers. We describe a subclinical, "pre-histologic" antibody-mediated rejection identified and characterized by a combination of novel molecular tools, donor-derived cell-free DNA (dd-cfDNA), and molecular histology. CASE REPORT: A 67-year-old kidney transplant recipient was found to have a marked elevation of dd-cfDNA on routine testing at 3 months post-transplant; other laboratory parameters were stable. A biopsy was performed, demonstrating the absence of rejection by traditional histology, but evidence of rejection was seen when tissue was evaluated using a research use molecular histology assay. Four months later, in the setting of persistently elevated dd-cfDNA, the patient developed graft dysfunction and was found to have C4d-negative ABMR, which was treated with improvement in both graft function and dd-cfDNA. CONCLUSION: This case highlighted the complementary use of dd-cfDNA and molecular histology to aid in the early detection and characterization of graft injury. Hybrid approaches combining these tools may allow more expeditious therapeutic intervention, leading to improved graft and patient outcomes.

Toxicokinetics of metformin-associated lactic acidosis with continuous renal replacement therapy.

A 70-year-old diabetic male patient with a baseline serum creatinine of 1.4 mg/dL presented with nausea and vomiting. He was diagnosed with metformin-associated lactic acidosis and acute kidney injury. He was managed with continuous veno-venous hemodiafiltration (CVVHDF). By measuring metformin concentration at different time intervals, we calculated the apparent volume of distribution of metformin at 34.7 L. The decline in serum metformin followed single-compartment first-order kinetics with an elimination rate constant of 0.0418/h and a serum half-life of 16.5 h; no metformin rebound was seen after discontinuation of CVVHDF. Using the previously calculated volume of distribution we calculated the expected serum metformin concentration 25 h post CVVHDF to be 3.0-3.7 µg/mL. The measured serum metformin of 3.4 µg/ml fell within the predicted range. During CVVHDF, dialyzer metformin clearance approximates 88.7 % of dialyzer urea clearance and 90.1 % of dialyzer creatinine clearance.

Induction Immunosuppressive Therapy for Kidney Transplant in Elderly Recipients: A Single-Center Experience.

OBJECTIVES: The number of elderly kidney transplant recipients is increasing, and age-tailored induction immunosuppression regimens are needed. We compared safety and efficacy of basiliximab versus thymoglobulin at various dosages. MATERIALS AND METHODS: Of 590 kidney transplants at our center from 2012 to 2019, 119 (20.1%) were for recipients over 65 years of age; 118 patients received deceased donor kidneys, and 1 received a related living donor kidney. We retrospectively reviewed medical records for demographics, baseline characteristics, donor characteristics, induction regimens, infectious complications, graft function, and patient survival. RESULTS: Patients were subdivided into the following 4 induction immunosuppression groups: basiliximab (n = 15, 12.6%), 3 mg/kg thymoglobulin (n = 8, 6.7%), 4.5 mg/kg thymoglobulin (n = 67, 56.3%), and 6 mg/kg thymoglobulin (n = 29, 24.4%). All patients received pulse doses of methylprednisolone followed by a prednisone taper. Other maintenance immunosuppression agents included tacrolimus and mycophenolic acid. Recipients in the basiliximab and 3 mg/kg thymoglobulin groups were older (median age ⟩70 years; P ⟨ .001). The 4.5 and 6 mg/kg thymoglobulin groups had higher proportions of African American patients and patients with calculated panel reactive antibody over 20%. There were significantly fewer infectious complications in the basiliximab and 3 mg/kg thymoglobulin groups. Despite differences in biopsy-proven acute rejection rates, estimated glomerular filtration rate and graft and patient survival rates at 1 year were similar across groups. All patients with biopsy-proven acute rejection were African American patients. CONCLUSIONS: Kidney transplant in patients ≥65 years is safe and feasible. Changes in this unique population's immune system warrant age-tailored regimens. We found that patients at low immunologic risk would benefit from basiliximab orthymoglobulin at 3 mg/kg. Regardless of calculated panel reactive antibodies, African American patients should be considered as high immunologic risk group forrejection, and higher thymoglobulin dosing should be considered.

A Rare Case of C3 Glomerulonephritis Presenting as Pulmonary Renal Syndrome.

Description C3 glomerulonephritis (C3GN) is a rare disease that falls under the umbrella of C3 glomerulopathy (C3G). Classic manifestations of C3G include acute renal failure, proteinuria, and hematuria. In some cases, extrarenal manifestations can include ocular drusen. Until recent reports, C3G manifesting with pulmonary symptoms has not been reported. In this report, we describe a patient that initially presented with hemoptysis and acute renal failure, eventually leading to a diagnosis of pulmonary renal syndrome. Renal biopsy showed C3GN. The patient's symptoms improved with pulse dose steroids, plasmapheresis and mycophenolate mofetil. C3G presenting with pulmonary symptoms is rare. Further research is needed to understand the mechanism of complement deposition in the lung parenchyma and to determine a standard therapy to treat these patients. Clinicians should be aware of the potential pulmonary manifestations that can be caused by C3GN.

Clinical predictors of recurrent stenosis and need for re-intervention in the cephalic arch in patients with brachiocephalic AV fistulas.

INTRODUCTION: Cephalic arch stenosis is one of the most common reasons for repeated endovascular intervention and eventual abandonment of access in hemodialysis patients. There is no prediction model to identify risk factors for recurrent cephalic arch stenosis. We have developed a mathematical model to predict the need for reintervention in brachiocephalic (BC) fistulas with recurrent cephalic arch stenosis. METHODS: Single-center retrospective analysis of 143 patients with a BC fistula referred to the vascular clinic for access dysfunction who underwent cephalic arch angioplasty were included for the analysis. Twelve-month post-index angioplasty data were analyzed using parametric, non-parametric and multiple regression models using SPSS software. RESULTS: The mean need for re-intervention in 1 year since first index visit was 2.46 ± 1.404. Statistically significant correlation (p≤0.001) for re-intervention was observed with the severity of stenosis at index visit, access flow, vessel wall diameter proximal to the stenosis, average venous pressure >50% of the delivered blood flow rate and prolonged bleeding for >30 minutes as a reason for referral. Three equations have been derived for calculating the need for re-intervention based on the diameter of the vessel wall proximal to the stenosis. CONCLUSIONS: Risk stratification of BC fistulas utilizing the above parameters could enable clinicians to identify accesses that are at risk for multiple re-interventions. Early identification of accesses that are at high risk for re-interventions at the cephalic arch might prolong access survival and reduce the cost for intervention by utilizing alternate strategies.

Membranous nephropathy with crescents associated with levamisole-induced MPO-ANCA vasculitis.

ANCA-associated vasculitis (AAV) is the most common cause of crescentic rapidly progressive glomerulonephritis (GN). Levamisole used as an adulterant in cocaine is increasingly recognized as a cause of AAV. We report the case of a 50 year old woman with atypical anti-MPO AAV associated with cocaine use and exposure to levamisole. In addition to the clinical and pathologic findings of crescentic GN, the patient also had biopsy evidence of secondary membranous nephropathy (MN). Although AAV and MN have been reported previously in the same patient and both have been induced by drug exposures, this is the first report of MN in a patient with AAV likely induced by levamisole. We suggest that MPO can cause both pauci-immune vasculitis and secondary membranous nephropathy in some cases, as in cases of levamisole-adulterated cocaine use.

Early Posttransplant Isolated v1 Lesion Does Not Need to Be Treated and Does Not Lead to Increased Fibrosis.

Acute vascular rejection (AVR) is characterized by intimal arteritis in addition to tubulitis and interstitial inflammation. It is associated with a poorer prognosis compared to tubulointerstitial rejection (AIR) and AVR is associated with a higher rate of graft loss than AIR. The prognosis and treatment of arteritis without tubulitis and interstitial inflammation (isolated v1 lesion) are still controversial. We report a case of a patient who had a biopsy of the kidney allograft for evaluation of slow graft function. The biopsy revealed an isolated v1 lesion. However, we chose not to augment immunosuppression. The patient's kidney allograft function improved over time with close monitoring. Repeat biopsy a year later showed no evidence of endothelialitis and relatively unchanged fibrosis and no other abnormalities. Although it is suggested that most cases of isolated v1 lesions will respond to corticosteroids or T cell depleting therapies, some cases will improve with conservative management. Further studies are needed to determine which cases could be managed conservatively.

Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram.

Allergic interstitial nephritis (AIN) is an underdiagnosed cause of acute kidney injury (AKI). Guidelines suggest that AIN should be suspected in a patient who presents with an elevated serum creatinine and a urinalysis that shows white cells, white cell casts, or eosinophiluria. Drug-induced AIN is suspected if AKI is temporally related to the initiation of a new drug. However, patients with bland sediment and normal urinalysis can also have AIN. Currently, a definitive diagnosis of AIN is made by renal biopsy which is invasive and fraught with risks such as bleeding, infection, and hematoma. Additionally, it is frequently unclear when a kidney biopsy should be undertaken. We describe a biopsy proven case of allergic interstitial nephritis which manifested on contrast enhanced Magnetic Resonance Imaging (MRI) as a striated nephrogram. Newer and more stable macrocyclic gadolinium contrast agents have a well-demonstrated safety profile. Additionally, in the presentation of AKI, gadolinium contrast agents are safe to administer in patients who demonstrate good urine output and a downtrending creatinine. We propose that the differential for a striated nephrogram may include AIN. In cases in which the suspicion for AIN is high, this diagnostic consideration may be further characterized by contrast enhanced MRI.

Outcome of patients on combined extracorporeal membrane oxygenation and continuous renal replacement therapy: a retrospective study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy used in the management of cardiopulmonary failure. Continuous renal replacement therapy (CRRT) is often added to the treatment for the correction of fluid and electrolyte imbalance in patients with acute kidney injury. Most of the literature on the use of combined ECMO and CRRT has been on pediatric patients. There are limited outcome data on the use of these combined modalities in adult patients. METHODS: This is a retrospective analysis of all the patients above the age of 18 years who underwent combined ECMO and CRRT at a tertiary care medical center during the period January 2007 to January 2012. The primary outcomes measured were mortality at one year and renal recovery or dialysis dependence at one month. RESULTS: A total of 40 patients who were treated concurrently with ECMO and CRRT were identified. The mean age was 47.01 ± 18.29 years. The most common indications for initiation of CRRT were combined fluid overload and electrolyte imbalance. Mortality at one month was (32/40) 80%. Among the 8 survivors (20%), 3 patients required continuation of hemodialysis and 5 patients were independent of dialysis at 30 days. CONCLUSIONS: Mortality of patients treated with combined ECMO and CRRT is high. Initiation of CRRT in these patients is simply an indicator of severity of illness and fatality. Younger age, higher arterial pH, left ventricular dysfunction and use of VA ECMO are associated with improved survival in these patients.

Hemodialysis patients have plasmatic hypercoagulability and decreased fibrinolytic vulnerability: role of carbon monoxide.

Chronic hemodialysis is associated with significant thrombophilia. Of interest, hemodialysis patients have increased carboxyhemoglobin (COHb) and exhaled carbon monoxide (CO), signs of upregulated heme oxygenase (Hmox) activity. Given that CO enhances plasmatic coagulation, we determined whether patients requiring chronic hemodialysis had an increase in endogenous CO, plasmatic hypercoagulability and decreased fibrinolytic vulnerability. Carbon monoxide was determined by noninvasive pulse oximetry measurement of COHb. Blood samples were obtained just before hemodialysis. Thrombelastographic methods to assess plasma coagulation kinetics, fibrinolytic kinetics, and formation of carboxyhemefibrinogen (COHF) were used. Hemodialysis patients (n = 45) had abnormally increased COHb concentrations of 2.2 ± 1.9%, indicative of Hmox upregulation. Coagulation and fibrinolytic parameter normal values were determined with normal individual (n = 30) plasma. Thirty-seven patients of the hemodialysis cohort had COHF formation (82.2%, [67.9%-92.0%]; mean, [95% confidence interval]), and many of this group of patients had abnormally great velocity of clot growth (73.3%, [58.1%-85.4%]) and strength (75.6%, [60.5%-87.1%]). Furthermore, over half of COHF positive patients had a hypofibrinolytic state, evidenced by an abnormally prolonged time to maximum rate of lysis (53.3%, [37.9%-68.6%]) and clot lysis time (64.4%, [48.8%-78.1%]). Carbon monoxide enhanced coagulation and diminished fibrinolytic vulnerability in hemodialysis patients. Future investigation of hemodialysis, CO-related thrombophilia is warranted.

Effective ionic dialysance/blood flow rate ratio: an indicator of access recirculation in arteriovenous fistulae.

Effective ionic dialysance (EID) is an online measure of hemodialysis (HD) effective urea clearance that is calculated using changes in dialysate sodium conductivity. Effective ionic dialysance is blood flow (Q(b)) dependent. The presence of significant (> or =5%) access recirculation (sAR) during dialysis lowers EID at a given Q(b), thereby lowering EID/Q(b). We propose using EID/Q(b) as a useful chairside tool for detection of sAR in arteriovenous fistulae (AVF). Data were collected from 47 patients with AVF (72% men, mean age 49 +/- 11.8 years, duration on dialysis 3.78 +/- 3.4 years, duration of fistula use 3.35 +/- 3.42 years) dialyzed with an high-efficiency dialyzer with a mass transfer area coefficient (KoA) of 1714 ml/min. Effective ionic dialysance were measured at regular intervals by the Gambro Phoenix dialysis system during treatments. The access recirculation (AR) and access blood flow (Q(a)) were measured using the reference standard saline dilution technique (Transonic HD-02 monitor). Among the 323 HD sessions where Q(b), EID, AR, and Q(a) were available, we identified 17 instances of sAR. The performance of EID/Q(b) as indicator of sAR was assessed by a receiver operator characteristic (ROC) curve (Stata version 10.1). The area under the ROC curve was 0.935 (95% confidence interval 0.869-1.000), which demonstrated a sensitivity of 76.5% and specificity of 96.4% at an EID/Q(b) < or =50% with a positive likelihood ratio of 21, negative likelihood ratio of 0.24, positive predictive value of 54.2%, and negative predictive value of 98.7%. We found similar test performance in patients who received HD with dialyzers with smaller surface areas and lower KoAs. The high specificity of EID/Q(b) makes it an excellent yet simple and early chairside indicator of AVF recirculation.