Renal tubular disease

Question 1

what is renal tubular acidosis

Answer 1

metabolic acidosis causes by impaired secretion by the kidney. hyperchloraemic metabolic acidosis with normal anion gap

Question 2

how many types of RTA are there

Answer 2

4

Question 3

where is type 1 RTA

Answer 3

distal

Question 4

what is type 1 RTA

Answer 4

inability to excrete H+ and generate acidic urine in distal tubule

Question 5

causes of type 1 RTA

Answer 5

inherited disorders, SLE, Sjogrens, drug related

Question 6

features type 1 RTA

Answer 6

rickets, osteomalacia (as buffering H+ with calcium). nephrocalcinosis with renal calculi, recurrent UTIs

Question 7

tests type 1 RTA

Answer 7

urine PH >5.5 despite met acidosis

Question 8

treatment type 1 RTA

Answer 8

oral sodium bicarbonate or citrate. ESRF may result from nephrocalcinosis

Question 9

where is type 2 RTA

Answer 9

proximal

Question 10

what is type 2 RTA due to

Answer 10

bicarbonate leak- defect in the HCO3- reabsorption in proximal tubule leading to excess HCO3- in the urine pH >5.5 leading to a metabolic acidosis

Question 11

which is rarer type 1 or 2

Answer 11

type 2- assoc with a more generalised tubular defect

Question 12

what is common in type 2 RTA

Answer 12

hypokalaemia- due to osmotic diuretic effect of decr HCO3- reabsorption, causing incr flow rate to distal tubular and incr K+ excretion

Question 13

treatment type 2

Answer 13

high doses bicarbonate >10mmol/kg/day

Question 14

what is type 3 RTA

Answer 14

rare combination of types 1 and 2

Question 15

what is type 4 RTA

Answer 15

hyperkalaemic. due to hyporeninaemic hypoaldosteronism. decr K+ and H+ excretion

Question 16

causes of type 4

Answer 16

Addisons, diabetic nephropathy, interstitial nephritis, drugs (K+ sparing diuretics, b blockers, NSAIDs)

Question 17

treatment type 4

Answer 17

remove any cause. fludrocortisone 0.1mg, furosemide, or calcium resonium

Question 18

what is Fanconi syndrome

Answer 18

proximal tubular dysfunction leading to loss of amino acids, glucose, PO4^3-, and HCO3 in urine

Question 19

what does Fanconi cause

Answer 19

dehydration, metabolic acidosis (type 2 RTA), osteomalacia/rickets, electrolyte disturbances

Question 20

what are the causes of Fanconi

Answer 20

congenital- idiopathic, Wilsons, tyrosinaemia, Lowe syndrome. Acquired- heavy metal poisoning, drugs, Sjogrens

Question 21

treatment Fanconi

Answer 21

remove cause replace losses. K+, sodium bicarb, PO4^3- and vit D supplements

Question 22

what is cystinosis

Answer 22

accumulation cysteine in lysosomes due to autosomal recessive defect

Question 23

what can cysteine deposits cause

Answer 23

Fanconi syndrome, visual impairment, myopathy, hypothyroidism, ESRF.

Question 24

treatment cystinosis

Answer 24

oral cysteamine. remove cause and replace losses

Question 25

what are the Hereditary Hypokalaemic Tubulopathies

Answer 25

Bartter syndrome, and Gitelman syndrome

Question 26

what is Bartter syndrome an inherited mutation in

Answer 26

co transporter targeted by LOOP diuretics

Question 27

what is Gitelmans syndrome a mutation in

Answer 27

co transporter targeted by THIAZIDE diuretics

Question 28

what does Bartter syndrome involve

Answer 28

low K+, metabolic alkalosis, hypercalciuria

Question 29

what does Gitelmans syndrome involve

Answer 29

low K+, metabolic alkalosis and hypocalciuria and low Mg2+