Tubulointerstitial nephritis

Question 1

What is tubulointerstitial nephritis?

Answer 1

A form of kidney inflammation occurring either through direct toxicity or because of an acute hypersensitivity

Question 2

What are the 2 most common forms of tubulointerstitial nephritis?

Answer 2

Drug-induced interstitial nephritis
Analgesic nephropathy

Question 3

What are some drugs that can cause drug-induced interstitial nephritis

Answer 3

ampicillin, rifampicin, thiazide diuretics, NSAIDs and allopurinol

Question 4

How does drug-induced interstitial nephritis usually present?

Answer 4

• Usually starts about 15 days after starting the drug
• Patients usually have a fever and occasionally a rash

Question 5

What will blood testing usually show in drug-induce tubulointerstitial nephritis?

Answer 5

Eosinophilia

Question 6

How is drug-induced interstitial nephritis managed?

Answer 6

• With withdrawal of the drug most recover although there can be long lasting damage
• In around a third the there is no obvious cause

Question 7

Describe the pathophysiology of analgesic nephropathy

Answer 7

Long-term analgesic use causes papillary necrosis in addition to tubulointerstitial nephritis

Question 8

How does analgesic nephropathy usually present?

Answer 8

• Patients usually develop anaemia and a range of non-specific symptoms e.g. headache
• Many develop a UTI

Question 9

How is analgesic nephropathy managed?

Answer 9

• With withdrawal of the drug most recover although there can be long lasting damage
• In around a third the there is no obvious cause

Question 10

What are some other substances that are toxic to the kidneys?

Answer 10

Urate, calcium, amyloid

Question 11

What are some conditions that can increase levels of urate, calcium and amyloid, causing tubulointerstitial nephritis

Answer 11

Chemotherapy in leukaemia (Hyperuricaemia)
Multiple myeloma (Hypercalcaemia and amyloid)