DISTAL RENAL TUBULAR (TYPE I) ACIDOSIS
A CASE REPORT
1 )Shyamali Datta M.D. 2) Jasninder Singh
1)Assisstant Professor, Department of Paediatrics; Mata Gujri Memorial Medical College ,Kishanganj, Bihar 2) P.G. Student, Department of Paediatrics; MtaGujri Memorial Medical College,Kishangang,Bihar
ABSTRACT
INTRODUCTION
`Renal tubular acidosis is not so common group of renal disorder presented as growth failure, refractory rickets,hypokalaemia & periodic paralysis. The disorder is due to defective H+ ion secretion in the distal tubule. Impairment in H+ ions secretion result in an inability to acidify the pH beyond 5.5 which retards the excretion of titrable acids (H2Po4) and NH4+ ions, thus retarding in a reduction in net acid excretion. The plasma bicarbonate is significantly reduced and may fall below 10meq/L.
The impairment in H+ ions secretion is most commonly thought to be due to a defect in in the luminal H+ATPase pump located in the intercalating cells of the collecting tubule. The H+ ATPase pump is primarily responsible for the Hydrogen secretion in the distal nephrones.
These patients tend to have urinary K+ wasting and hypokalaemia. The aetiology of hypokalaemia is unclear but is thought to be due to increased potassium secretion by distal tubular cells in the setting of diminished H+ ion secretion.
Hypercalciuria, hyperphosphatemia, nephrolithiasis (calcium phosphate stones) and nephrocalcinosis are frequently associated with untreated type 1 RTA. The hypercalciuria is thought to be due to 1) increased calcium phosphate release from bone as a result of bone buffering of excess acid and 2) reduction in tubular calcium reabsorption secondary to chronic acidosis. The hypercalciuria, alkaline urine, and reduced excretion of citrate in the urine ( which normally prevents calcium crystallization) promotes the precipitation of calcium phosphate and stone formation. The hypocitraturia is thought to be due to the effects of acidosis and hypokalaemia on proximal tubule reabsorption.
Most different conditions have been associated with Type1 RTA ,but in children RTA is most often a primary hereditary condition.
The loss of calcium salts from bones in these patients can result in failure to thrive, rickets and stunning of growth in children.
CASE REPORT
A 7 year old female child presented with growth failure ,features of rickets and history of multiple attacks of paralysis. On examination she was retarded in height and weight, had flaccid paralysis of limbs and features of rickets which was not responding to Vitamine D therapy previously.
On investigation she showed metabolic acidosis, hypokalaemia, high urinary ph nephrolithiasis and increased renal cortical echogenicity in ultrasonography.Treat—ment with alkali and potassium was satisfactory, vitamine D and calcium were also given.
KEY WORDS
Distal Renal tubular acidosis, Rickets(Refractory), Hypokalaemic periodic paralysis, growth failure
HOW TO CITE THIS ARTICLE :Datta.S; Singh j; Distal Renal Tubular Acidosis: A case Report; J Evolution Med. Dental Sci.______
Financial or other cometing Interest : None Submission Peer Review Acceptance Published Corresponding Author: Dr. Shyamali Datta Ashirbad Appartment , KhudiramSarani CoochBehar-736101, West Bengal E-Mail : ------