Incomplete distal renal tubular acidosis in children (original) (raw)

Renal tubular acidosis in childhood

2007

Increased knowledge on the genetics, the pathophysiology, the natural history and the treatment of renal tubular acidosis (RTA) has begun to clarify this often confusing field. To help pediatricians better acquainted with the physiological and genetic basis of the various types of RTA, to facilitate early diagnosis and treatment with the ultimate aim of preventing the significant growth failure and chronic kidney failure of undiagnosed and untreated patients with RTA, we reviewed new data on the mechanisms of growth retardation in patients with RTA. RTA should be included in the differential diagnosis of a child with growth failure, rickets and metabolic acidosis. The diagnostic work-up and treatment are succinctly presented in this review.

A Pediatric Case of Long-term Untreated Distal Renal Tubular Acidosis

Childhood Kidney Diseases

Distal renal tubular acidosis (dRTA) is a rare renal tubular disorder characterized by normal anion gap metabolic acidosis, hypokalemia, and high urine pH. It can be inherited or acquired. In untreated pediatric patients with dRTA, rickets and growth retardation are common. We report the case of a 12-year-old Lao girl who presented with typical clinical features of dRTA with severe bone deformities that developed after a bedridden state due to a bicycle accident at the age of 8 years. Initial laboratory tests revealed metabolic acidosis with a normal anion gap, hypokalemia, and alkali urine. Renal ultrasonography revealed bilateral medullary nephrocalcinosis. Whole exome sequencing revealed no pathogenic mutations. After treatment with oral alkali, potassium, and vitamin D, she could walk and run. Later, she underwent corrective orthopedic surgeries for bony deformities. Thus, in pediatric dRTA patients, despite severe symptoms remaining untreated, accurate diagnosis and proper management can improve quality of life.

Natural history of primary distal renal tubular acidosis treated since infancy

Journal of Pediatrics, 1982

Clinical and pathophysiologic studies were performed in five unrelated children with primary distal renal tubular acidosis who were diagnosed during infancy and followed for 3 to 9 89 years. All patients had permanent defects in hydrogen ion secretion, sodium reabsorption, and concentrating capacity. A transient, age-related, proximal tubular defect in sodium and bicarbonate reabsorption was also present. Renal bicarbonate wasting was mainly observed during the first years of life and progressively decreased with advancing age. Glomerular filtration rate remained within normal limits. Following sustained therapy with sodium and potassium bicarbonate, the patients had optimal growth, arrest of progression of nephrocalcinosis, and lack of other characteristic features of the disease with the exception of polyuria. Dosage of alkali was mainly determined by the magnitude of the renal bicarbonate loss and decreased progressively from a maximum of 3.9 to 10.0 mEq/kg/day during the first year of life to about 3 mEq/kg/day at or beyond 6 years of age. The total dosage of alkali required could be derived by the sum of the urinary excretion of bicarbonate plus 2 mEq/kg/day, which represents mean endogenous acid production. Although caleiuria was normal when metabolic acidosis was corrected, patients with higher urinary sodium excretion had higher urinary excretion of calcium and thus were at greater risk of developing nephrocalcinosis if therapy was not carefully controlled.

Secondary distal renal tubular acidosis in association with urological abnormalities

Nephrology Dialysis Transplantation, 1997

Letters nephropathy and distal RTA developed end-stage renal [ The views expressed in Letters do not necessarily disease during the follow-up. present the views of the Editor.] Vesico-ureteric and other urological conditions could secondarily be associated with distal RTA resulting in growth Secondary distal renal tubular acidosis in association retardation and other metabolic derangements. Early recogwith urological abnormalities nition and adequate treatment of distal RTA with alkali can reverse growth failure in children [ 5]. Obstruction causes a Sir, voltage-dependent distal acidification defect with reduced Distal renal tubular acidosis (RTA) is a hyperchloraemic H-ATPase activity [1]. Associated interstitial renal disease type of metabolic acidosis characterized by the inability of would produce rate-dependent distal RTA. Children prethe distal nephron to maximally acidify the urine pH to less senting with short stature should also be evaluated for distal than 5.5 despite spontaneous or induced metabolic acidosis RTA and underlying urological disease if there is any sugges-[ 1,2]. This study is the first report of association of vesicotion of obstructive voiding. In children, distal RTA can often ureteric reflux and bladder outlet obstruction with distal be a clue for underlying urological diseases, such as reflux RTA. nephropathy, calling for early diagnosis and surgical manage-Thirteen patients presented with resistant rickets, ment in order to prevent end-stage renal disease. Simple tests dwarfism, and myopathy. They were found to have urological of urinary acidification and high index of suspicion could abnormalities and DRTA. The diagnosis of distal RTA was detect RTA in patients presenting with growth failure. based on: (i) normal anion gap metabolic acidosis and (ii) basal urine pH above 5.5 in the absence of urinary tract Departments of Nephrology, R. K. Sharma infection; (iii) an inability to lower urine pH after ammonium Endocrinology and Urology, R. Jha chloride and/or frusemide test in patients who did not have Sanjay Gandhi Post Graduate Institute V. L. Bhatia spontaneous metabolic acidosis; (iv) absence of advanced of Medical Sciences, R. Kapoor renal failure (GFR>25 ml/min/1.73 m2); (v) good hydration. Raebareli Road, A. Gupta Distal acidification tests included the ammonium chloride Lucknow 226014 loading test (0.1 g/kg) and urine pH measurement for the India next 5 h with one blood pH after 2 h; the frusemide test (1-2 mg/kg or 80 mg frusemide and urine pH hourly for 1. Kurtzman NA. Disorders of distal acidification. Kidney Int 1990; 5 h); and urine anion gap. Plasma concentrations of sodium, 38: 720-727 2. Caruna RJ, Buckalew VM. The syndrome of distal (type 1) renal potassium, chloride, bicarbonate, calcium, phosphate and tubular acidosis: clinical and laboratory findings in 58 cases. alkaline phosphatase were measured with an automated Medicine 1988; 67: 84-99 analyser. GFR was assessed by creatinine clearance and 3. Wrong OM, Feest TG. The natural history of distal renal tubular radionuclide study (using 99mTc-DTPA). Ultrasound of kid

Atypical presentation of distal renal tubular acidosis in two siblings

Pediatric Nephrology, 2008

Primary distal renal tubular acidosis (dRTA) is an inherited disease characterized by the inability of the distal tubule to lower urine pH <5.50 during systemic acidosis. We report two male siblings who presented with severe hyperchloremic metabolic acidosis, high urinary pH, nephrocalcinosis, growth retardation, sensorineural hearing loss, and hypokalemic paralysis. Laboratory investigations revealed proximal tubular dysfunction (low molecular weight proteinuria, generalized hyperaminoaciduria, hypophosphatemia with hyperphosphaturia, and hypouricemia with hyperuricosuria). There was significant hyperoxaluria and laboratory evidence for mild rhabdomyolysis. Under potassium and alkali therapy, proximal tubular abnormalities, muscular enzymes, and oxaluria normalized. A homozygous mutation in the ATP6V1B1 gene, which is responsible for dRTA with early hearing loss, was detected in both siblings. In conclusion, proximal tubular dysfunction and hyperoxaluria may be found in children with dRTA and are reversible under appropriate therapy.

Long-term outcome in children with primary distal renal tubular acidosis

Indian pediatrics, 2005

To evaluate complications in adequately treated children with distal renal tubular acidosis (RTA) and to identify factors influencing their development. Records of patients with primary distal RTA followed for 2 or more years at this hospital were reviewed. Case records were examined for age at onset of symptoms and at initiation of treatment, treatment details, follow-up and complications. Height, weight and growth velocity were expressed as standard deviation score (SDS) during different periods of follow-up. Regression analysis was performed to evaluate factors influencing increase in height and weight SDS. P value of less than 0.05 was considered significant. Of 18 patients (eleven boys), the diagnosis was established at the median (range) age of 6 yr (1.5-13 yr). These patients were followed up for a median (range) period of 4 yr (2-18.5 yr). Short stature (height SDS <-2) was noted in all patients at the time of diagnosis with median (range) height SDS of -5.2(-7.5 - -0.4)....

Primary Distal renal tubular acidosis: case series

Anwer Khan Modern Medical College Journal

Primary Distal renal tubular acidosis is an infrequent tubular disorder with complex pathophysiology that present with poor growth, skeletal changes and sometimes life-threatening hypokalemia. Here we present two siblings one girl and one boy with a consanguineous parents presented with polyuria, polydipsia, failure to thrive and skeletal deformity. Both cases showed non-anion gap metabolic acidosis with alkaline urine and the younger brother had periodic paralysis due to hypokalemia. After diagnosis and treatment they showed good response with alkali therapy. AKMMC J 2022; 13(1) : 56-59

Distal renal tubular acidosis in children with chronic hydronephrosis

The Journal of Pediatrics, 1976

The difference between the Pco~ of alkalinized urine and the Pco~ of blood has been proposed as an indirect means of assessing distal nephron H + secretion. Following oral bicarbonate loading and alkalinization of the urine to pH ~ 7.2, eight of nine children with chronic hydronephrosis and four children with idiopathic distal RTA had low (U-B)Pco.~ values when compared with seven normal subjects. This finding leads us to conclude that chronic hydronephrosis may cause a form of distal RTA which persists many years after surgical diversion procedures have been carried out.

Distal Renal Tubular Acidosis Screening by Urinary Acidification Testing in Mexican Children

Revista de investigación clínica; organo del Hospital de Enfermedades de la Nutrición

Primary distal renal tubular acidosis is a clinical disorder characterized by hyperchloremic metabolic acidosis, hypercalciuria, hypocitraturia, urinary acidification impairment, hypokalemia, metabolic bone disease, and nephrocalcinosis. Urinary acidification ability may be evaluated by an acidification test or maximum urinary pCO2 assessment with alkaline urine. The maximum urinary pCO2 test using acetazolamide and sodium bicarbonate is an easy test to confirm the lack of urine acidification in distal renal tubular acidosis in children. To determine the urinary acidification ability using the maximum urinary pCO2 assessment in a group of children with a distal renal tubular acidosis diagnosis. Thirty children were evaluated (13 males and 17 females); 23 children had been diagnosed with distal renal tubular acidosis by other physicians and were under alkali treatment with potassium and sodium citrates (21) and bicarbonate (2), and five children were not under alkali treatment. Two c...

Distal Renal Tubular Acidosis in Adolescence with Severe Growth Retardation and Nephrocalcinosis

Journal of Nepal Medical Association

Chronic acidosis is an important, often overlooked cause of growth retardation. Here we present the case of a girl with distal renal tubular acidosis who had visited multiple hospitals before the diagnosis was made. She presented to us in adolescence with non anion gap metabolic acidosis, hypokalemia, severe growth retardation and nephrocalcinosis. In 18 months follow up with alkali therapy, she had good weight gain and growth velocity. Keywords: growth retardation; hypokalemia; nephrocalcinosis; renal tubular acidosis.