Polycythaemia and Anaemia in Newborn Monozygotic Twin Girls (original) (raw)

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.

Renal tubular acidosis in infants and children

The Journal of Pediatrics, 1972

... Edelmann, CM, Jr., Barnett, HL, Stark, H., Boichis, H., and Rodriguez-Soriano, J.: Astandardized test of renal concentrating capacity in children ... Seldin, DW, and Wilson, JD: Renal tubular acidosis, in Stanbury, JB, Wyngaar-den, JB, and Fredrlckson, DS, editors: The metabolic ...

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.

Incomplete distal renal tubular acidosis in children

Acta Paediatrica, 2020

AimTo describe incomplete distal renal tubular acidosis (iDRTA) in paediatric patients, a term used for the diagnosis of patients who do not develop spontaneous overt metabolic acidosis but are unable to acidify the urine in response to an ammonium chloride load.MethodsTests used to explore urinary acidification were revised. In addition, publications in English extracted from 161 entries yielded by a PubMed database search, using ‘incomplete distal renal tubular acidosis’ as keyword, were reviewed.ResultsIncomplete distal renal tubular acidosis has mostly been identified in adults with autoimmune diseases, nephrolithiasis, nephrocalcinosis and/or osteopenia. iDRTA has been reported in few paediatric patients with rickets, congenital abnormalities of kidney and urological tract and/or growth failure. The pathophysiological mechanisms potentially responsible for the defect of urinary acidification are discussed as well as the clinical and biochemical findings of iDRTA described in ch...

Evaluation of Failure to Thrive: Diagnostic Yield of Testing for Renal Tubular Acidosis

PEDIATRICS, 2003

Background. Failure to thrive (FTT) poses a diagnostic dilemma for pediatricians. The kidney disorder that is considered most often is renal tubular acidosis (RTA). However, the prevalence of RTA may be overestimated, leading to unnecessary referrals for subspecialty evaluation. Moreover, preliminary data suggest that venous blood gas (VBG) testing may provide a more accurate measurement of the serum bicarbonate concentration than routine biochemical testing.

Acidosis increases magnesiuria in children with distal renal tubular acidosis

Pediatric Nephrology, 2004

In experimental animals, metabolic acidosis increases renal magnesium (Mg) excretion, whereas metabolic alkalosis reduces it. The objective of this study was to examine renal magnesium handling (U Mg ) in children with primary distal renal tubular acidosis (DRTA). We measured U Mg in 11 children (3 females, 8 males, aged 6.9€4.9 years) with primary DRTA. They were studied either during spontaneous acidosis post treatment removal (3 patients) or after ammonium chloride (100 mmol/m 2 ) induced acidosis (8 patients), and then following oral sodium bicarbonate load (4 g/1.73 m 2 ). During acidosis (plasma pH 7.28€0.09, bicarbonate 13.2€4.3 mEq/l), U Mg was elevated (U Mg/Cr 0.18€0.06 mg/mg, normal values 0.1€0.06, P=0.003) although plasma Mg (P Mg ) was in the normal range (1.93€0.31 mg/dl, controls 1.77€0.19, P=NS). After acute correction of metabolic acidosis (plasma pH 7.44€0.05, bicarbonate 25.6€1.6 mEq/l, P<0.001; urine pH 7.52€ 0.28, bicarbonate 86.9€39.1 mEq/l), U Mg decreased significantly (P=0.003), returning to control values after about 2 h (U Mg/Cr 0.09€0.06 mg/mg). Bicarbonate load resulted not only in reduction in U Mg but also in a decrease in urinary calcium excretion (U Ca/Cr ) from 0.46€0.17 mg/mg to 0.14€0.12 mg/mg (P<0.001). We conclude that in children with primary DRTA, urinary Mg excretion is markedly increased and that this defect, like the hypercalciuric defect, is correctable by sodium bicarbonate administration.

Neonatal Acidosis With Nephrocalcinosis: A Clinical Approach

American Journal of Kidney Diseases, 2009

INDEX WORDS: Glycogen storage disease; infant; lactic acidosis; nephrocalcinosis. P ersistent metabolic acidosis with increased anion gap during infancy is a strong indicator of an underlying metabolic disorder. Association of acidosis with nephrocalcinosis is uncommon and occurs primarily in patients with renal tubular disorders. We present an infant with lactic acidosis, nephrocalcinosis, and hyperlipidemia caused by glycogen storage disorder type I and discuss pertinent issues.

Clinical and laboratory approaches in the diagnosis of renal tubular acidosis

Pediatric nephrology (Berlin, Germany), 2015

In the absence of a gastrointestinal origin, a maintained hyperchloremic metabolic acidosis must raise the diagnostic suspicion of renal tubular acidosis (RTA). Unlike adults, in whom RTA is usually secondary to acquired causes, children most often have primary forms of RTA resulting from an inherited genetic defect in the tubular proteins involved in the renal regulation of acid-base homeostasis. According to their pathophysiological basis, four types of RTA are distinguished. Distal type 1 RTA, proximal type 2 RTA, mixed-type 3 RTA, and type 4 RTA can be differentiated based on the family history, the presenting manifestations, the biochemical profile, and the radiological findings. Functional tests to explore the proximal wasting of bicarbonate and the urinary acidification capacity are also useful diagnostic tools. Although currently the molecular basis of the disease can frequently be discovered by gene analysis, patients with RTA must undergo a detailed clinical study and labo...

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...