Case Report: Patient with Hepatitis C, p-ANCA, and Cryoglobulin Antibodies Presenting with Necrotizing Crescentic p-ANCA Glomerulonephritis

Hepatitis C (HCV) infection has a prevalence of 3 million infected individuals in the United States, according to recent Center for Disease Control reports, and can have various renal manifestations. Cryoglobulins, antibodies that precipitate at colder temperatures in vitro, are a relatively common cause of renal disease in HCV infection. The cryoglobulin proteins can form occlusive aggregates in small glomerular capillary lumina or deposit in other areas of the glomerulus, resulting in hypocomplementemia, proteinuria, hematuria, and renal injury. The typical biopsy pattern is that of membranoproliferative glomerulonephritis (MPGN). There are, however, other HCV-related patterns of glomerular injury. Anti-neutrophil cytoplasmic antibodies (ANCA) are known to exist in HCV-infected patients. In many reported cases, ANCA serologic testing may appear positive due to cross-reactivity of the immune assays; however, the biopsy findings do not support ANCA-associated crescentic glomerulonephritis (GN)/vasculitis as the primary cause of glomerular injury. There are rare reports of microscopic polyangiitis (MPA) p-ANCA vasculitis, in patients with HCV infection. In comparison with the MPGN pattern of cryoglobulinemic glomerular injury, biopsies from these HCV-infected patients with concomitant MPA revealed a crescentic GN, associated with normal serum complement levels. We present a case of HCV-associated glomerular disease with the surprising biopsy finding of necrotizing and crescentic p-ANCA GN, with a background, low-grade mesangial immune complex GN. Thus, p-ANCA disease should also be considered in HCV-infected patients, in addition to the more typical lesions of MPGN or cryoglobulinemic GN

Exacerbation of Minimal Change Disease Following mRNA COVID-19 Vaccination.

BACKGROUND Minimal change disease is a common cause of nephrotic syndrome in adults. There are few reported cases of vaccine-related podocytopathy with nephrotic-range proteinuria in the setting of a minimal change disease history. There have been rare reports of acute renal damage following vaccination to prevent COVID-19 and some cases of exacerbation of ongoing nephropathy. This report is a 33-year-old man with a 22-year history of nephrotic syndrome due to minimal change disease which exacerbated following a third dose of an mRNA SARS-CoV-2 vaccine for COVID-19. CASE REPORT We report a case of nephrotic syndrome after the third dose of the BNT162b2 mRNA COVID-19 vaccine. The patient presented with mild edema in the bilateral lower extremities and sacrum. Laboratory investigations confirmed nephrotic-range proteinuria and hypoalbuminemia. A kidney sonogram demonstrated mild renal parenchymal disease and a small non-obstructing right renal calculus. Renal biopsy revealed diffuse podocyte foot process effacement, punctuate IgG podocyte cytoplasmic staining, and minimal global glomerulosclerosis, consistent with a diagnosis of a diffuse podocytopathy with a minimal change disease phenotype. The patient was started on oral prednisone treatment, which led to remission of his symptoms and normalization of lab test results with normal BUN and Cr and resolution of proteinuria. Treatment was tapered off over the course of 28 weeks. CONCLUSIONS We presents a case of longstanding minimal change disease that showed exacerbation following a third dose of an mRNA vaccine for SARS-CoV-2. Although this may be a rare association, this case supports that patients with chronic glomerulonephritis need to be monitored

Differential distribution of muscle and skin sympathetic nerve activity in patients with end-stage renal disease

End-stage renal disease (ESRD) is characterized by resting sympathetic overactivity. Baseline muscle sympathetic nerve activity (MSNA), which is governed by baroreflexes and chemoreflexes, is elevated in ESRD. Whether resting skin sympathetic nerve activity (SSNA), which is independent from baroreflex and chemoreflex control, is also elevated has never been reported in renal failure. The purpose of this study was to determine whether sympathetic overactivity of ESRD is generalized to include the skin distribution. We measured sympathetic nerve activity to both muscle and skin using microneurography in eight ESRD patients and eight controls. MSNA was significantly (P = 0.025) greater in ESRD (37.3 ± 3.6 bursts/min) when compared with controls (23.1 ± 4.4 bursts/min). However, SSNA was not elevated in ESRD (ESRD vs. controls, 17.6 ± 2.2 vs. 16.1 ± 1.7 bustst/min, P = 0.61). Similar results were obtained when MSNA was quantified as bursts per 100 heartbeats. We report the novel finding that although sympathetic activity directed to muscle is significantly elevated, activity directed to skin is not elevated in ESRD. The differential distribution of sympathetic outflow to the muscle vs. skin in ESRD is similar to the pattern seen in other disease states characterized by sympathetic overactivity such as heart failure and obesity

Acute interstitial nephritis observed with three different triggering agents.

A 70-year-old female patient developed acute interstitial nephritis (AIN) after treatment with non-steroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPI), and Bromhexine. Renal biopsy confirmed the diagnosis, and the patient was treated with oral prednisone. Careful attention to timing of acute kidney injury (AKI) is crucial to diagnosing AIN

Advances in Autosomal Dominant Polycystic Kidney Disease: A Clinical Review.

Polycystic kidney disease (PKD) is a multiorgan disorder resulting in fluid-filled cyst formation in the kidneys and other systems. The replacement of kidney parenchyma with an ever-increasing volume of cysts eventually leads to kidney failure. Recently, increased understanding of the pathophysiology of PKD and genetic advances have led to new approaches of treatment targeting physiologic pathways, which has been proven to slow the progression of certain types of the disease. We review the pathophysiologic patterns and recent advances in the clinical pharmacotherapy of autosomal dominant PKD. A multipronged approach with pharmacologic and nonpharmacologic treatments can be successfully used to slow down the rate of progression of autosomal dominant PKD to kidney failure

Primary membranous nephropathy with concomitant IgA nephropathy

Membranous nephropathy (MN), an autoimmune glomerulonephritis which can occur in primary and secondary forms, is one of the most common inflammatory glomerulopathies in elderly patients. The pathophysiology of the primary form is generally due to circulating immunoglobulin (IgG4) antibodies which often target phospholipase A2 receptors (anti-PLA2R) and Thrombospondin Type 1 Domain containing 7A (anti THSD7A). IgA nephropathy is one of the most common autoimmune glomerular diseases in the world and presents with a spectrum of disease ranging from asymptomatic mild hematuria and proteinuria to rapidly progressive crescentic glomerulonephritis. We present a rare case of concomitant IgA and primary MN in a single patient treated successfully with renin–angiotensin–aldosterone blockade, corticosteroids, and calcineurin inhibitors. The peak proteinuria was near 7.5–8 g protein/g creatinine by various measures. Serum creatinine remained normal, and anti-PLA2R was detectable and decreased with successful treatment. Clinicians should be aware of the possibility of two glomerular disorders in patients with glomerulonephritis and atypical presentations for any single disorder

Acute Kidney Injury after Pembrolizumab-Induced Adrenalitis and Adrenal Insufficiency

Pembrolizumab is an immune checkpoint inhibitor that targets the programmed cell death protein 1 (PD-1) antigen and induces an immune response against tumor tissues. It has been successful in inducing remission in patients with severe metastatic disease, often refractory to other chemotherapeutic agents. The risk of injury of other organ systems has been noted with reported cases of glomerular disease and endocrine disease. In addition, hypophysitis as well as dermatological and gastroenterological side effects have been reported. Renal injury with immune checkpoint inhibitors like nivolumab and pembrolizumab is usually mediated via interstitial nephritis, though glomerular disease presentations like anti-neutrophil cytoplasmic antibody-associated vasculitis, immune complex disease, and thrombotic microangiopathy have also been reported. We report a 70-year-old Caucasian male who underwent treatment with pembrolizumab for adenocarcinoma of the lung. He developed acute adrenal insufficiency and concomitant severe hypotension upon presentation. He did not require renal replacement therapy, rather his severe acute kidney injury resolved with hydration, normalization of blood pressures with vasopressors, and treatment with high-dose corticosteroids. His urinary indices (fractional excretion of urea, FEUrea) and clinical course were highly suspicious for acute tubular necrosis that resolved quickly after treating his underlying adrenalitis. The urinary sediment, proteinuria, and clinical course were not typical for the usually expected renal lesion of interstitial nephritis in patients treated with immune checkpoint inhibitors