Table 2.

Causes of renal tubular acidosis (RTA)

Causes of proximal RTA		Causes of distal RTA		Causes of RTA type 4
isolated defect	generalized defect	with hypokalemia	with hyperkalemia
Autosomal dominant Proximal RTA from unknown gene mutation	Primary (genetic) inborn errors of metabolism (Cystinosis, Wilson disease, galactosemia, hereditary fructose intolerance, methylmalonic acidemia, glycogen storage diseases)	Calcium-induced tubular damage Idiopathic hypercalciuria Primary hyperparathyroidism Hypervitaminosis D Medullary sponge kidney
Autosomal recessive Sodium bicarbonate symporter (NBC1) protein mutation in the SLC4A4 gene	Dysproteinemic states (Myeloma, monoclonal gammopathy)	Autoimmune diseases Sjögren syndrome Rheumatoid arthritis SLE Polyarteritis nodosa Thyroiditis Primary biliary cirrhosis Chronic active hepatitis Cryoglobulinemia	Decreased effective intravascular volume of any cause Sickle cell disease Urinary tract obstruction SLE Renal transplant rejection Amyloidosis	Aldosterone deficiency Addison disease 21-Hydroxylase deficiency Hyporeninemia Diabetic nephropathy Tubulointerstitial disease HIV IgM monoclonal gammopathy
Inherited CA II deficiency caused by mutations in the CA2 gene – associated with mental retardation, cerebral calcifications and osteopetrosis (Sly syndrome)	Honeybee stings	Idiopathic causes Marfan syndrome Wilson disease Ehlers-Danlos syndrome	Aldosterone resistance Obstructive uropathy Sickle cell nephropathy Amyloidosis Diabetic nephropathy Lupus nephritis Pseudohypoaldosteronism
	Secondary hyperparathyroidism with chronic hypocalcemia Vitamin D deficiency
	Tubulointerstitial diseases (Sjögren syndrome, medullary cystic disease, renal transplantation)
	Nephrotic syndrome
	Amyloidosis
	Paroxysmal nocturnal hemoglobinuria
	Toxins (lead, mercury, copper, cadmium, glue sniffing)

Drugs as causes of proximal RTA		Drugs as causes of distal RTA		Drugs as causes of RTA type 4
isolated defect	generalized defect	with hypokalemia
CA inhibitors	Ifosfamide, aminoglycosides, expired tetracycline, streptozocin, azacitidine (antimetabolites), mercaptopurine, valproic acid, ranitidine, lead, cadmium, mercury, antiretroviral drugs, propylene glycol-containing drugs	Amphotericin B, lithium carbonate, methicillin (meticillin), foscarnet, ifosfamide, toluene		Reduced NH4+ production (hypoaldosteronism) K+-sparing diuretics (spironolactone, eplerenone, amiloride, triamterene), cotrimoxazole, ACEI, angiotensin II receptor type 1 antagonists, renin inhibitors, NSAIDs, ciclosporin, tacrolimus, heparin

ACEI, angiotensin-converting enzyme inhibitors; CA, carbonic anhydrase; SLE, systemic lupus erythematosus.