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Advances in Chronic Kidney Disease Jul 2018Proximal renal tubular acidosis (pRTA) is an inherited or acquired clinical syndrome in which there is a decreased bicarbonate reclamation in the proximal tubule... (Review)
Review
Proximal renal tubular acidosis (pRTA) is an inherited or acquired clinical syndrome in which there is a decreased bicarbonate reclamation in the proximal tubule resulting in normal anion gap hyperchloremic metabolic acidosis. In children, pRTA may be isolated but is often associated with a general proximal tubular dysfunction known as Fanconi syndrome which frequently heralds an underlying systemic disorder from which it arises. When accompanied by Fanconi syndrome, pRTA is characterized by additional renal wasting of phosphate, glucose, uric acid, and amino acids. The most common cause of inherited Fanconi syndrome in the pediatric age group is cystinosis, a disease with therapeutic implications. In this article, we summarize the clinical presentation and differential diagnosis of pRTA and Fanconi syndrome and provide a practical approach to their evaluation in children.
Topics: Acidosis, Renal Tubular; Child; Cystinosis; Dent Disease; Fanconi Syndrome; Humans; Kidney Tubules, Proximal; Oculocerebrorenal Syndrome
PubMed: 30139461
DOI: 10.1053/j.ackd.2018.05.006 -
Southern Medical Journal Nov 2000Renal tubular acidosis is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary... (Review)
Review
Renal tubular acidosis is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary acidification have allowed us to discern various molecular mechanisms responsible for these syndromes. This report relates clinical disorders of acidification to the underlying defective mechanisms responsible for them. A clinical classification of these disorders is presented, integrating each disorder with the prevailing serum potassium concentration. That renal tubular acidosis can be associated with low, normal, or high serum potassium concentration is now explainable by identifying the specific defect in transport causing each syndrome.
Topics: Acidosis, Renal Tubular; Aldosterone; Female; Humans; Hyperkalemia; Hypokalemia; Male
PubMed: 11095551
DOI: No ID Found -
The New England Journal of Medicine Aug 1996
Topics: Acidosis, Renal Tubular; Citrates; Citric Acid; Humans; Kidney Calculi
PubMed: 8692251
DOI: 10.1056/nejm199608293350917 -
Nephrology, Dialysis, Transplantation :... Aug 2021Distal renal tubular acidosis (dRTA) is characterized by an impaired ability of the distal tubule to excrete acid, leading to metabolic acidosis. Associated...
Distal renal tubular acidosis (dRTA) is characterized by an impaired ability of the distal tubule to excrete acid, leading to metabolic acidosis. Associated complications include bone disease, growth failure, urolithiasis and hypokalaemia. Due to its rarity, there is limited evidence to guide diagnosis and management; however, available data strongly suggest that metabolic control of the acidosis by alkali supplementation can halt or revert almost all complications. Despite this, cohort studies show that adequate metabolic control is present in only about half of patients, highlighting problems with treatment provision or adherence. With these clinical practice points the authors, part of the working groups tubulopathies in the European Rare Kidney Disease Reference network and inherited kidney diseases of the European Society for Paediatric Nephrology, aim to provide guidance for the management of patients with dRTA to facilitate adequate treatment and establish an initial best practice standard against which treatment of patients can be audited.
Topics: Acidosis; Acidosis, Renal Tubular; Child; Cohort Studies; Humans; Hypokalemia; Kidney
PubMed: 33914889
DOI: 10.1093/ndt/gfab171 -
The Journal of Urology Mar 1989Renal tubular acidosis is a term applied to several conditions in which metabolic acidosis is caused by specific defects in renal tubular hydrogen ion secretion. Three... (Review)
Review
Renal tubular acidosis is a term applied to several conditions in which metabolic acidosis is caused by specific defects in renal tubular hydrogen ion secretion. Three types of renal tubular acidosis generally are recognized based on the nature of the tubular defect. Nephrolithiasis occurs only in type I renal tubular acidosis, a condition marked by an abnormality in the generation and maintenance of a hydrogen ion gradient by the distal tubule. A forme fruste of type I renal tubular acidosis has been described in which the characteristic defect in distal hydrogen ion secretion occurs in the absence of metabolic acidosis (incomplete renal tubular acidosis). Type I renal tubular acidosis is a heterogeneous disorder that may be hereditary, idiopathic or secondary to a variety of conditions. Secondary type I renal tubular acidosis in sporadic cases is associated most commonly with autoimmune diseases, such as Sjögren's syndrome and systemic lupus erythematosus, and it occurs more frequently in women than men. Nephrolithiasis, which may occur in any of the subsets of type I renal tubular acidosis, accounts for most of the morbidity in adults and adolescents. Major risk factors for nephrolithiasis include alkaline urine, hypercalciuria and hypocitraturia. In addition, we found hyperuricosuria in 21 per cent of the patients with type I renal tubular acidosis with nephrolithiasis. The most frequently occurring risk factor, hypocitraturia, is due to decreased filtered load and/or to increased tubular reabsorption of filtered citrate. While increased tubular reabsorption may be due to systemic acidosis, hypocitraturia occurs in incomplete renal tubular acidosis. Furthermore, alkali therapy (either bicarbonate or citrate salts) increases citrate excretion in complete and incomplete type I renal tubular acidosis. These data suggest that hypocitraturia in type I renal tubular acidosis may be due to a defect in proximal tubule function. Hypercalciuria appears to have 2 causes. It may be due to metabolic acidosis, usually in children with a hereditary defect in urine acidification. In other cases familial idiopathic hypercalciuria causes nephrocalcinosis and nephrolithiasis resulting in distal tubular damage and type I renal tubular acidosis. In these latter cases hypercalciuria is present in complete and incomplete type I renal tubular acidosis. Potassium citrate appears to reduce calcium excretion in both types of hypercalciuric type I renal tubular acidosis.(ABSTRACT TRUNCATED AT 400 WORDS)
Topics: Acidosis, Renal Tubular; Calcium; Chronic Kidney Disease-Mineral and Bone Disorder; Citrates; Humans; Kidney Calculi
PubMed: 2645431
DOI: 10.1016/s0022-5347(17)40997-9 -
Pediatric Nephrology (Berlin, Germany) Mar 2023The clinical manifestations of primary distal renal tubular acidosis usually begin in childhood, but the disease is caused by a genetic defect that persists throughout... (Review)
Review
The clinical manifestations of primary distal renal tubular acidosis usually begin in childhood, but the disease is caused by a genetic defect that persists throughout life. This review focuses on the complications of distal tubular acidosis that occur or remain long-term such as nephrocalcinosis and urolithiasis, growth impairment, bone mineralization, severe hypokalemia, kidney cysts, and progressive kidney failure, as well as other persistent manifestations that occur independent of acidosis but are associated with some inherited forms of the disease. The pathogenic factors responsible for kidney failure are discussed in particular because it is a complication to which different publications have recently drawn attention and which affects a high percentage of adults with primary distal renal tubular acidosis. The need to maintain optimal metabolic control of the disease and scheduled clinical follow-up throughout life and the importance of organizing protocols for the transition of patients to adult nephrology services are emphasized.
Topics: Adult; Humans; Acidosis, Renal Tubular; Hypokalemia; Acidosis; Nephrocalcinosis; Renal Insufficiency
PubMed: 35543873
DOI: 10.1007/s00467-022-05546-w -
Pediatric Nephrology (Berlin, Germany) May 1990The term renal tubular acidosis (RTA) is applied to a group of transport defects in the reabsorption of bicarbonate (HCO3-), the excretion of hydrogen ions, or both. On... (Review)
Review
The term renal tubular acidosis (RTA) is applied to a group of transport defects in the reabsorption of bicarbonate (HCO3-), the excretion of hydrogen ions, or both. On clinical and pathophysiological grounds, RTA can be separated into three main types: distal RTA (type 1), proximal RTA (type 2) and hyperkalaemic RTA (type 4). Some patients present combined types of proximal and distal RTA or of hyperkalaemic and distal RTA. Diagnosis of RTA should be suspected when a patient presents a normal plasma anion gap, and hyperchloraemic metabolic acidosis. A normal plasma anion gap (Na(+)-[Cl- + HCO3-] = 8-16 mEq/l) reflects loss of HCO3- from the extracellular fluid via the gastro-intestinal tract or the kidney, dilution of extracellular buffer or administration of hydrochloric acid (HCl) or its precursors. Distinction of RTA from other disorders is greatly facilitated by the study of the urine anion gap (Na+ + K+ - Cl-). This index estimates the urinary concentration of ammonium in a patient with hyperchloraemic metabolic acidosis. A negative urine anion gap (Cl- much greater than Na+ + K+) suggests the presence of gastro-intestinal or renal loss of HCO3-, while a positive urine anion gap (Cl- less than Na+ + K+) is indicative of a distal acidification defect. Determination of plasma potassium, of urine pH at low plasma HCO3- concentration, and of urine PCO2 and fractional excretion of HCO3- at normal plasma HCO3- concentration permits the differentiation between the various types of RTA.
Topics: Acidosis, Renal Tubular; Child; Humans
PubMed: 2205272
DOI: 10.1007/BF00857675 -
Advances in Chronic Kidney Disease Jul 2018In contrast to distal type I or classic renal tubular acidosis (RTA) that is associated with hypokalemia, hyperkalemic forms of RTA also occur usually in the setting of... (Review)
Review
In contrast to distal type I or classic renal tubular acidosis (RTA) that is associated with hypokalemia, hyperkalemic forms of RTA also occur usually in the setting of mild-to-moderate CKD. Two pathogenic types of hyperkalemic metabolic acidosis are frequently encountered in adults with underlying CKD. One type, which corresponds to some extent to the animal model of selective aldosterone deficiency (SAD) created experimentally by adrenalectomy and glucocorticoid replacement, is manifested in humans by low plasma and urinary aldosterone levels, reduced ammonium excretion, and preserved ability to lower urine pH below 5.5. This type of hyperkalemic RTA is also referred to as type IV RTA. It should be noted that the mere deficiency of aldosterone when glomerular filtration rate is completely normal only causes a modest decline in plasma bicarbonate which emphasizes the importance of reduced glomerular filtration rate in the development of the hyperchloremic metabolic acidosis associated with SAD. Another type of hyperkalemic RTA distinctive from SAD in which plasma aldosterone is not reduced is referred to as hyperkalemic distal renal tubular acidosis because urine pH cannot be reduced despite acidemia or after provocative tests aimed at increasing sodium-dependent distal acidification such as the administration of sodium sulfate or loop diuretics with or without concurrent mineralocorticoid administration. This type of hyperkalemic RTA (also referred to as voltage-dependent distal renal tubular acidosis) has been best described in patients with obstructive uropathy and resembles the impairment in both hydrogen ion and potassium secretion that are induced experimentally by urinary tract obstruction and when sodium transport in the cortical collecting tubule is blocked by amiloride.
Topics: Acidosis, Renal Tubular; Aldosterone; Animals; Epithelial Sodium Channels; Humans; Hydrogen-Ion Concentration; Hyperkalemia; Membrane Potentials; Nephrons; Potassium; Pseudohypoaldosteronism; Renal Insufficiency, Chronic; Sodium; Ureteral Obstruction
PubMed: 30139459
DOI: 10.1053/j.ackd.2018.05.004 -
British Journal of Hospital Medicine Aug 1989Disordered renal acid-base handling can be associated with a wide variety of diseases. Although early diagnosis is important to avoid complications, renal tubular... (Review)
Review
Disordered renal acid-base handling can be associated with a wide variety of diseases. Although early diagnosis is important to avoid complications, renal tubular acidosis is frequently not recognized. The pathophysiology, clinical features, diagnosis and treatment of this group of disorders are described in the light of recent advances in our knowledge of renal tubular transport mechanisms.
Topics: Acidosis, Renal Tubular; Diagnosis, Differential; Humans
PubMed: 2670024
DOI: No ID Found -
Journal of Nephrology 2006The proximal tubule reabsorbs approximately 80% of the filtered load of bicarbonate. Defects in the process of bicarbonate reabsorption result in loss of bicarbonate and... (Review)
Review
The proximal tubule reabsorbs approximately 80% of the filtered load of bicarbonate. Defects in the process of bicarbonate reabsorption result in loss of bicarbonate and proximal renal tubular acidosis. Global proximal tubule dysfunction is known as the Fanconi's syndrome. Both isolated proximal renal tubular acidosis and the Fanconi's syndrome can result from inherited defects or can be acquired. This review will discuss the mechanisms that cause defects in proximal tubule bicarbonate transport as well as the common causes of isolated proximal renal tubular acidosis and the Fanconi syndrome.
Topics: Acidosis, Renal Tubular; Bicarbonates; Humans; Ion Transport; Kidney Tubules, Proximal; Sodium-Bicarbonate Symporters
PubMed: 16736440
DOI: No ID Found