An Overlooked Link between IgA Nephropathy and Lithium Toxicity: A Case Report.

Lithium is one of the first-line agents for treating bipolar disorder. Although this agent is highly effective in treating mood disorders, renal toxicity is a frequent side effect. Lithium metabolism is affected by sodium-lithium counter-transporter (SLC-T) in erythrocytes. The high activity of SLC-T can result in decreased urinary lithium clearance and may lead to accumulation of lithium in the distal renal tubular cells, causing lithium toxicity. SLC-T is a genetic marker in primary hypertension (HTN), HTN in pregnancy, diabetic nephropathy, and IgA nephropathy (IgA-N) with HTN. Patients with IgA-N have been reported to have enhanced SLC-T activity and are likely to have considerably lower renal fractional clearance of lithium. Therefore, patients taking lithium for bipolar disorder with coexisting IgA-N can have severe lithium-induced nephropathy and nephrotoxicity even at therapeutic serum levels. Serum lithium levels reflect only extracellular lithium concentration. However, lithium exerts its effects once it has moved to the intracellular compartment. This phenomenon illustrates the reason why patients with significantly elevated serum levels might be asymptomatic. Creatinine clearance is inversely related to the duration of lithium therapy. The degree of interstitial fibrosis on renal biopsy has been known to be associated with the duration of lithium therapy and cumulative dose. We present a case with a past medical history of bipolar disorder treated with lithium for almost 20 years. His family history was significant for HTN. The patient was diagnosed with renal insufficiency of unknown causes, for which he underwent renal biopsy. The renal biopsy showed a typical lithium-induced tubulointerstitial nephritis and a coincidental finding of IgA-N. We suspect a high activity of SLC-T seen in IgA-N, and the adverse effects of lithium on SLC-T activity might cause reduction of urinary lithium clearance and accumulation of lithium in distal renal tubular cells, contributing to nephrotoxicity. There is a lack of the literature on the coexistence of IgA-N and lithium nephrotoxicity. We recommend in patients with concomitant IgA-N, taking lithium, more frequent monitoring of renal functions, and dose adjustments may reduce the risk of lithium-induced nephrotoxicity.

Metabolic Acidosis, Hyperkalemia, and Renal Unresponsiveness to Aldosterone Syndrome: Response to Treatment with Low-Potassium Diet.

Gordon syndrome involves hyperkalemia, acidosis, and severe hypertension (HTN) with hypercalciuria, low renin and aldosterone levels. It is commonly observed in children and adolescents. Such patients respond successfully to sodium restriction and thiazide diuretics. In this article, we present three cases of metabolic acidosis, hyperkalemia, and renal unresponsiveness to aldosterone (MeHandRU Syndrome). All three patients did not have HTN or hypercalciuria and demonstrated normal renin and aldosterone levels. These patients did not respond to thiazide-type diuretic therapy and salt restriction. Two males (aged 55- and 62-year) and a female patient (aged 68-year) presented to the clinic with unexplained hyperkalemia (5.9 mEq/L, 5.9 mEq/L and 6.2 mEq/L, respectively). On physical examination, blood pressure (BP) was found to be normal (<140/90 mm Hg). Over the counter potassium supplement, nonsteroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, potassium sparing diuretic use, as well as hyporeninemic hypoaldosteronism states such as diabetes mellitus were excluded. Plasma renin and aldosterone levels were normal. All three patients had low transtubular potassium gradient, despite high serum potassium levels. None of the patients reported a family history of hyperkalemia or kidney failure. All failed to demonstrate a response to hydrochlorothiazide and salt restriction. After careful consideration, strict low potassium diet (<2 g/day) was initiated in consultation with the dietician. Diuretic therapy was discontinued while BP remained within normal range (<140/90 mm Hg). At eight weeks, all three patients demonstrated normalization of potassium and correction of acidosis. At follow-up of six months, all patients are maintaining a normal potassium level. We suggest that potassium restriction can be successful in patients presenting with MeHandRU syndrome.

Acute kidney injury secondary to thrombotic microangiopathy associated with idiopathic hypereosinophilic syndrome: a case report and review of the literature.

BACKGROUND: Renal involvement in idiopathic hypereosinophilic syndrome is uncommon. The mechanism of kidney damage can be explained as occurring via two distinct pathways: (1) thromboembolic ischemic changes secondary to endocardial disruption mediated by eosinophilic cytotoxicity to the myocardium and (2) direct eosinophilic cytotoxic effect to the kidney. CASE PRESENTATION: We present a case of a 63-year-old Caucasian man who presented to our hospital with 2 weeks of progressively generalized weakness. He was diagnosed with idiopathic hypereosinophilic syndrome with multiorgan involvement and acute kidney injury with biopsy-proven thrombotic microangiopathy. Full remission was achieved after 8 weeks of corticosteroid therapy. CONCLUSION: Further studies are needed to investigate if age and absence of frank thrombocytopenia can serve as a prognostic feature of idiopathic hypereosinophilic syndrome, as seen in this case.

Subcutaneous defibrillators for dialysis patients.

Defibrillation can be successfully provided by the subcutaneous implantable cardioverter defibrillator (ICD) without the leads. In contrast, traditional ICDs require leads that can cause central venous stenosis, lead-induced endocarditis, and carry the risk of tricuspid regurgitation by valve adhesion, perforation, coaptation interference, or entanglement. Central venous stenosis, infection, and tricuspid regurgitation are all critically important considerations in hemodialysis patients. Recent reports are supporting the use of subcutaneous ICDs in renal patients maintained on long-term hemodialysis. This article provides the risks associated with leads of traditional defibrillators and raises awareness of the subcutaneous ICD and their benefits for hemodialysis patients.

Arteriovenous fistula maturation in patients with permanent access created prior to or after hemodialysis initiation.

INTRODUCTION: Multiple factors and comorbidities have been implicated in the ability of arteriovenous fistulas (AVF) to mature, including vessel anatomy, advanced age, and the presence of coronary artery disease or peripheral vascular disease. However, little is known about the role of uremia on AVF primary failure. In this study, we attempt to evaluate the effect of uremia on AVF maturation by comparing AVF outcomes between pre-dialysis chronic kidney disease (CKD) stage five patients and those who had their AVF created after hemodialysis (HD) initiation. METHODS: We included 612 patients who underwent AVF creation between 2003 and 2015 at the University of Miami Hospital and Jackson Memorial Hospital. Effects of uremia on primary failure were evaluated using univariate statistical comparisons and multivariate logistic regression analyses. RESULTS: Primary failure occurred in 28.1% and 26.3% of patients with an AVF created prior to or after HD initiation, respectively (p = 0.73). The time of HD initiation was not associated with AVF maturation in multivariate logistic regression analysis (p = 0.57). In addition, pre-operative blood urea nitrogen (p = 0.78), estimated glomerular filtration rate (p = 0.66), and serum creatinine levels (p = 0.14) were not associated with AVF primary failure in pre-dialysis patients. CONCLUSIONS: Our results show that clearance of uremia with regular HD treatments prior to AVF creation does not improve the frequency of vascular access maturation.

The first description of severe anemia associated with acute kidney injury and adult minimal change disease: a case report.

INTRODUCTION: Acute kidney injury in the setting of adult minimal change disease is associated with proteinuria, hypertension and hyperlipidemia but anemia is usually absent. Renal biopsies exhibit foot process effacement as well as tubular interstitial inflammation, acute tubular necrosis or intratubular obstruction. We recently managed a patient with unique clinical and pathological features of minimal change disease, who presented with severe anemia and acute kidney injury, an association not previously reported in the literature. CASE PRESENTATION: A 60-year-old Indian-American woman with a history of hypertension and diabetes mellitus for 10 years presented with progressive oliguria over 2 days. Laboratory data revealed severe hyperkalemia, azotemia, heavy proteinuria and progressively worsening anemia. Urine eosinophils were not seen. Emergent hemodialysis, erythropoietin and blood transfusion were initiated. Serologic tests for hepatitis B, hepatitis C, anti-nuclear antibodies, anti-glomerular basement membrane antibodies and anti-neutrophil cytoplasmic antibodies were negative. Complement levels (C3, C4 and CH50) were normal. Renal biopsy unexpectedly displayed 100% foot process effacement. A 24-hour urine collection detected 6.38 g of protein. Proteinuria and anemia resolved during six weeks of steroid therapy. Renal function recovered completely. No signs of relapse were observed at 8-month follow-up. CONCLUSION: Adult minimal change disease should be considered when a patient presents with proteinuria and severe acute kidney injury even when accompanied by severe anemia. This report adds to a growing body of literature suggesting that in addition to steroid therapy, prompt initiation of erythropoietin therapy may facilitate full recovery of renal function in acute kidney injury.