Tubular Diseases of the Kidney Types Clinical Features Diagnosis with Treatment

Tubular Diseases of the Kidney

  • The tubular diseases of the kidney have various pre­sentations.

POLYCYSTIC KIDNEY DISEASE

Autosomal dominant polycystic kidney disease

  • This is a relatively common cause of end-stage renal disease (ESRD).
  • The kidneys are enlarged with multiple cysts.
  • The cysts contain straw-colored or hemorrhagic fluid. The cysts are spherical and may be even a few ems in size.
  • There is also i’nterst’itial fibrosis and nephrosclerosis.

Tubular Diseases of the Kidney1

Tubular Diseases of the Kidney Types Clinical Features Diagnosis with Treatment


Clinical Features of POLYCYSTIC KIDNEY DISEASE

  • · May present ~t any age.
  • · Symptoms begin in 3rd or 4th decade.
  • · There is chronic pain in the flanks.
  • · Acute pain may be due to UTI, and urinary tract
  • obstruction by clot, stone or haemorrhage.
  • · Nocturia may be present.
  • · Nephrolithiasis (renal stones) is common.
  • · There is hypertension especially in adults.
  • · ESRD sets in rapidly after 3rd decade.
  • · There is renal failure due to hypertension, infec­tions, ureteral obstruction.
  • · There may be cysts in the spleen, pancreas and ovaries.
  • · There may be intracranial aneurysms and sub­arachnoid haemorrhage.
  • · There may be MVP (mitral valve prolapseL AR, TR.
  • · Urine pH is low.

Diagnosis

  • Ultrasound – is the best technique for polycystic dis­ease.
  • CT scan

POLYCYSTIC KIDNEY DISEASE  Treatment

  • Control of hypertension Treatment of infections Dialysis, Renal transplant

Autosomal recessive polycystic kidney disease

  • Here the disease usually leads to death in neonatal or childhood period. There is hepatic fibrosis, portal hypertension and liver failure.
  • It is diagnosed by ultrasound.

Treatment

  • Treat hypertension and UTI Dialysis and transplant
  • For hepatic fibrosis and haemorrhage – sclero-­therapy and portosystemic shunts.

VON HIPPELLINDAU DISEASE

  • This autosomal dominant disease is characterized by hemangioblastomas of retina and central nervous system.
  • There are bilateral renal cysts.

MEDULLARY SPONGE KIDNEY

  • It is a congenital autosomal dominant disease with bilateral renal involvement.
  • There are cystic dilatations of collecting ducts. Patients have renal stones, infection, hematuria.
  • Diagnosis
    • IVP (Intravenous Pyelogram), and ultra­sound.
  • Treatment-
    • Treat stones, infections, metaboli[.: ab­normalities.

MEDULLARY CYSTIC NEPHRONOPHTHISIS

  • Presents during childhood with polyuria, growth re­tardation, anaemia, renal failure.

LIDDLE’S SYNDROME

  • It is au(osomal dominant with hyperaldosteronism­consisting of hypertension, hypokalemia, metabolic alkalosis.
  • Treatment
    •  is low-sodium diet and potassium-spar­ing diuretics.

BARTTER’S SYNDROME

  • There is hypokalemia, metabolic alkalosis, low blood pressure, growth retardation, nephrocalcinosis.
  • Treatment
    • Potassium supplement, increased in­take of sodium, spironolactone, NSAIDs, ACE inhibi­tors.

GITELMAN’S SYNDROME

  • There is hypokalemia, metabolic alkalosis, normal blood pressure, hypomagnesemia, hypocalciuria.

RENAL TUBULAR ACIDOSIS

  • It is a disorder of renal acidification.
  • There is hyperchloremic metabolic acidosis with nor­mal serum anion gap {Na+ – (Cl- + HC03‘)}.
  • There is defective bicarbonate reabsorption from proximal tubule.
  • There is decreased production of ammonia, decreased secretion of proton from the distal tubule.

There are four types of RTA

  • Type 1 and’ 2 may be inherited or acquired.
  • Type 3 is very rare.
  • Type 4 is usually acquired and associated with hypoaldosterorlism.

  • Type 1 RTA -This is also called distal RTA.

    • The distal nephron does not lower the urine pH be­cause the collecting ducts permit diffusion of hydro­gen ions back into the blood from the lumen of the duct.
    • Chronic acidosis lowers the tubular reabsorption of calcium leading to hypercalciuria and secondary hy­perparathyroidism.
    • The hypercalciuria, alkaline urine and low levelS-of urine citrate lead to calcium phosphate stones and nephrocalcinosis.
    • There is growth retardation. There is bone disease.
    • There is polyuria and hypokalemia.
    • There may be intercurrent illnesses.
    • Acidosis and hypokalemia can lead to death. There is normal anion gap metabolic acidosis. Urine pH is >5.5
    • On administration of ammonium chloride urine pH does not fall below 5.5 and systemic acidosis wors­ens.
  • Treatment -,
    • Alkali supplements – Sodium bicarbonate and Shohl’s solution are used.
    • Relatives of type 1 RTA should be screened for the disease.

  • Type 2 or Proximal RTA

     

    • Type 2 RTA occurs as a part of generalized disorder of proximal tubule.
    • There is hyperchloremic acidosis like Fanconi syn­drome.
    • Bicarbonate absorption is defective therefore there is bicarbonaturia.
    • There is hypophosphatemia and low calcitriol levels leading to rickets and osteomalacia.
    • There is hypercalciuria.
    • In Type 2 – RTA the urine is not so much alkaline as in type 1 RTA. The urine anion gap is positive.
  • Treatment
    • Alkali is given in large amounts 5-15 meqjkg body weight j day.
    • Thiazide diuretic and low salt diet is given.
    • Potassium supplements may also be given with alkali.

  • Type 4 RTA It is also called hyperkalemic distal RTA.

    • There is abnormal distal tubule secretion of potas­sium and hydrogen ions leading to hyperchloremic acidosis and hyperkalemia.
    • It is an acquired disorder. There is renal insufficiency.
    • The urine is acidic with pH <5.5.
    • Etiology of Type 4 RTA may be hyporeninemic hypoaldosteronism, diabetic nephropathy, obstructive uropathy, sickle cell disease, NSAIDs, ACE inhibitors, heparin, potassium sparing diuretics.
  • Treatment
    • Low potassium diet Potassium lowering therapy Loop diuretics
    • Exchange resins
    • Stop aldosterone antagonists.
    • It is a generalized defect in proximal tubule trans­port. There is proximal or Type 2 RTA.
    • There is glucosuria with normal serum glucose, hy­pophosphatemia, hypouricaemia, hypokalemia.
    • Rickets and osteomalacia are common due to hypo­phosphatemia.
    • Metabolic acidosis, polyuria, hypokalemia may be severe.
  • Treatment . ,
    • Phosphate supplement and calcitriol
    • Alkali
    • Increase salt and water intake Potassium alkali salts.