Renal tubular acidosis

Nephrolithiasis (NL) is a common condition worldwide. The incidence of NL and nephrocalcinosis (NC) has been increasing, along with their associated morbidity and economic burden. The etiology of NL and NC is multifactorial and includes both environmental components and genetic components, with multiple studies showing high heritability. Causative gene variants have been detected in up to 32% of children with NL and NC. Children with NL and NC are genotypically heterogenous, but often phenotypically relatively homogenous, and there are subsequently little data on the predictors of genetic childhood NL and NC...

BACKGROUND AND PURPOSE: Primary mitochondrial diseases (PMDs) are common inborn errors of energy metabolism, with an estimated prevalence of one in 4300. These disorders typically affect tissues with high energy requirements, including heart, muscle and brain. Epilepsy may be the presenting feature of PMD, can be difficult to treat and often represents a poor prognostic feature. The aim of this study was to develop guidelines and consensus recommendations on safe medication use and seizure management in mitochondrial epilepsy...

INTRODUCTION: This study was designed to determine the mineral composition of calculi in nephrocalcinosis with nephrolithiasis, diagnose the underlying disease and monitor the course of renal function in patients with nephrocalcinosis-nephrolithiasis. METHODS: Renal calculi extruded in a series of eight patients with nephrocalcinosis were analysed using Fourier transmission infrared spectrometry. In four patients, next generation sequencing (NGS) using a nephrocalcinosis-nephrolithiasis panel was performed to determine the nature of the underlying disease...

INTRODUCTION: Pathogenic variants in TARS2 are associated with combined oxidative phosphorylation deficiency 21 (COXPD21), an autosomal recessive disorder usually presenting as mitochondrial encephalomyopathy. Kidney impairment has been documented in a minority of COXPD21 patients, mostly with distal renal tubular acidosis. CASE REPORT: We report on the first COXPD21 patient with generalized tubular dysfunction and early childhood progression to chronic kidney disease (CKD)...

BACKGROUND: Fanconi-Bickel syndrome is characterized by hepatorenal disease caused by anomalous glycogen storage. It occurs due to variants in the SLC2A2 gene. We present a male patient of 2 years 7 months old, with failure to thrive, hepatomegaly, metabolic acidosis, hypophosphatemia, hypokalemia, hyperlactatemia. RESULTS: Exome sequencing identified the homozygous pathogenic variant NM_000340.2(SLC2A2):c.1093 C > T (p.Arg365Ter), related with Fanconi-Bickel syndrome...

Gender disparities in kidney stone formation are well-known. Women generally have slightly acidic blood and higher urine pH when compared with men, which makes them more vulnerable to calcium stone formation, yet the mechanism is still unclear. We aimed to examine the role of sex in stone formation during hypercalciuria and urine alkalinization through acetazolamide (Acz) and calcium gluconate (CaG) supplementation, respectively, for 4 weeks in wild-type (WT) and hypercalciuric [TRPC3 KO (-/-)] male and female mice...

The disposal of ammonia, the main proton buffer in the urine, is important for acid-base homeostasis. Renal ammonia excretion is the predominant contributor to renal net acid excretion, both under basal condition and in response to acidosis. New insights into the mechanisms of renal ammonia production and transport have been gained in the past decades. Ammonia is the only urinary solute known to be produced in the kidney and selectively transported through the different parts of the nephron. Both molecular forms of total ammonia, NH3 and NH4 + , are transported by specific proteins...

Medullary sponge kidney (MSK) is a description of radiographic features. However, the pathogenesis of MSK remains unclear. MSK is supposed to be the cause of secondary distal renal tubular acidosis (dRTA), although there are case reports suggesting that MSK is a complication of primary dRTA. In addition to these reports, we report three patients with metabolic acidosis and MSK, in whom primary dRTA is confirmed by molecular genetic analyses of SLC4A1 and ATP6V1B1 genes. With a comprehensive genetics first approach using the 100,000 Genomes Rare Diseases Project dataset the association between MSK and primary dRTA is examined...

INTRODUCTION: Congenital glucose-galactose malabsorption (CGGM) is a rare autosomal recessive disorder that primarily causes chronic intractable diarrhea. This study aims to describe the clinical history, laboratory profile, diagnostic workflow, and management of the first patient reported with CGGM in Mexico. METHODS: The case involves a Mexican female infant with recurrent admissions to the emergency room since birth due to chronic diarrhea. RESULTS: The infant was born at term by C-section with a birth weight of 3...

Renal tubular acidosis (RTA) involves dysfunction of the renal tubular system, which leads to electrolyte abnormalities and acid-base dysregulation. The case we present here discusses a patient with a past medical history of psoriatic arthritis who presented to the emergency department with progressive generalized weakness and anorexia in the preceding four weeks. She was found to have profound hypokalemia (1.2 mmol/L), hyperchloremic metabolic acidosis, and multiple other electrolyte abnormalities. Following an extensive workup, her principle problem was deemed to be distal (type 1) RTA...

INTRODUCTION: The occurrence of hyperkalemic renal tubular acidosis (RTA) in the post-transplantation period is likely underestimated, and its identification remains important to offer adequate medical management. Transplant recipients frequently present with clinical and biological characteristics that may be associated with the occurrence of this complication. METHODS: This was a single-center retrospective study that compared transplanted patients with hyperkalemic RTA and a control group to identify variables associated with the occurrence of this complication...

This special article describes the achievements and impact of Dr. Todd Siu-Toa Ing, MBBS, (1933-2023) on the field of nephrology as recounted by a colleague from Hong Kong, a U.S. nephrologist ex-trainee, and the daughter of an important mentor. Dr. Ing was a founding member of the International Society for Hemodialysis. He made important discoveries regarding the diagnosis of renal tubular acidosis and electrolyte transport in the gastrointestinal tract and published many innovative findings relating to peritoneal and hemodialysis...

BACKGROUND: Fanconi-Bickel syndrome (FBS) is a rare autosomal recessive disorder characterized by impaired glucose and galactose utilization as well as proximal renal tubular dysfunction. METHODS: Clinical, biochemical, genetic, treatment, and follow-up data for 11 pediatric patients with FBS were retrospectively analysed. RESULTS: Hepatomegaly (10/11), short stature (10/11) and hypophosphataemic rickets (7/11) were the most common initial symptoms...

Refeeding syndrome is the potentially fatal shift in fluids and electrolytes that may occur in malnourished patients after receiving artificial refeeding. Its hallmark feature is hypophosphatemia, although other electrolytes might also be affected. Fanconi syndrome is a generalized dysfunction of the proximal tubule characterized by proximal renal tubular acidosis (RTA), phosphaturia, glycosuria, aminoaciduria, and proteinuria. The etiology of Fanconi syndrome can be either acquired or inherited, and drugs, among them tenofovir, are a common acquired cause of this disease...

High dietary phosphorus intake (P-In) and high acid loads may adversely affect kidney function. In animal models, excessive phosphorus intake causes renal injury, which, in humans, is also inducible by chronic metabolic acidosis. We thus examined whether habitually high P-In and endogenous acid production during childhood and adolescence may be early indicators of incipient renal inflammatory processes later in adulthood. P-In and acid-base status were longitudinally and exclusively determined by biomarker-based assessment in 277 healthy children, utilizing phosphate and net acid excretion (NAE) measurements in 24 h urine samples repeatedly collected between the ages of 3 and 17 years...

OBJECTIVE: To assess the impact of kidney stone disease (KSD) and its treatment on the health-related quality of life (HRQOL) of high-risk stone formers with hyperparathyroidism, renal tubular acidosis, malabsorptive disease, and medullary sponge kidney. PATIENTS AND METHODS: The Wisconsin Stone Quality of Life questionnaire was used to evaluate HRQOL in 3301 patients with a history of KSD from 16 institutions in North America between 2014 and 2020. Baseline characteristics and medical history were collected from patients, while active KSD was confirmed through radiological imaging...

BACKGROUND: Kidney collecting ducts are comprised of principal cells and intercalated cells, with intercalated cells playing a crucial role in kidney acid-base regulation through H+ and HCO3- secretion. Despite its significance, the molecular mechanisms controlling intercalated cell development remain incompletely understood. METHODS: To investigate the specific role of Foxp1 in kidney tubular system, we specifically deleted Foxp1 expression in kidney distal nephrons and collecting ducts...

Carbonic anhydrase II deficiency is an extremely rare inborn error of metabolism that constitutes a triad osteopetrosis, renal tubular acidosis and intracerebral calcification. Unlike other subtypes of osteopetrosis, the presence of developmental delay and relative infrequency of skeletal fractures may not be a typical signs of symptoms indolent trajectory. This case report demonstrates a 11-year-old boy who had a bilateral midshaft tibial fracture despite low mechanism of injury. He was found to have severe respiratory distress with hypokalemia shortly after arriving to the emergency department venous blood gas (VBG) showed moderate metabolic acidosis...

See Bonus NeoBriefs videos and downloadable teaching slides Metabolic acidosis can manifest in the neonatal period and cause significant morbidity and mortality in neonates. Preterm infants are at an even higher risk of developing metabolic acidosis. If the acidosis results from a dysfunction of acid-base homeostasis by the renal system, the disorder is known as renal tubular acidosis (RTA). In this review, we will describe renal development and normal acid-base homeostasis by the renal system. We will also discuss the pathophysiology of the different types of RTA, laboratory findings to aid in diagnosis, and treatment considerations...

Neurological manifestations such as polyneuropathy are reported in 8-49% of cases with Sjögren's Syndrome (SjS), but central nervous system involvement is seldom described. We report a 46-year-old woman with a history of SjS with distal renal tubular acidosis and autoimmune thyroiditis. She consulted in the emergency room for a five-days history of holocranial headache and explosive vomiting. Fundoscopy showed bilateral papilledema. Brain computed tomography (CT) without contrast showed diffuse encephalic edema, with effacement ofsulci and restriction ofperitruncal cisterns...