1. Tubular and interstitial diseases
Most forms of tubular injury involve the interstitium as well.So
diseases involving these two components are discussed together.
A - Tubulointerstitial nephritis.
B- Ischemic or toxic tubular injury.

2. A- Tubulointerstitial nephritis
Def: diseases affecting tubules and interstitial tissues of the kidney.
1-Pyelonephritis
Pelvis of the kidney is commonly involved in bacterial infection, hence pyelo
Cause: bacterial infection as E-coli ,B. proteus, B. pyocyaneus , streptococcus faecalis and others
PF: -obstruction Vesicoureteric reflux
-Instrumentation Female sex.
-Pregnancy DM.
-Bilhaziasis.

4. Acute PN Routes of infection Grossly: Hematogenous -Ascending
From boil
-Ascending
Acute PN
It is a suppurative inflammation of the pelvicalyceal system and the renal parenchyma; it is usually bilateral.
Grossly:
-Enlarged kidney Congested PCS
-Yellow streaks from papillae to cortex.

5. Acute PN
Yellow foci of pus

6. Acute pyelonephritis
MSC: 1-The pelvicalyceal system is acutely inflamed.
2-patchy interstial suppurative inflammation,
3- Intratubular aggregates of neutrophils,
4-tubulitis and tubular necrosis

7. Clinical features: Prognosis :
1-Frequency and dysuria (lower urinary tract infection).
2-Rigors, pain and tenderness over the loins (pyelonephritis).
Prognosis :
It may resolve; progress to chronic pyelonephritis or to acute renal failure

8. Chronic PN Gross Two forms: -Small sized kidney (contracted).
1- Reflux nephropathy: more common unilateral or bilateral leading to chronic renal insufficiency.
2- obstructive PN: The disease can be bilateral, as with congenital anomalies of the urethra ,or unilateral, as occurs with calculi and unilateral obstructive lesions of the ureter
Gross
-Small sized kidney (contracted).
-Irregular outer surface due to retraction of the capsule.
-Distorted pelvicalyceal system .

9. Chronic pyelonephritis

10. Chronic PN

11. Microscopic: -Periglomerular fibrosis
-Dilated tubules containing hyaline casts (thyroidization)
-Thick walled BVs
- Interstitial fibrosis and chronic inflammatory cell infiltration of lymphocytes, plasma cells, and occasionally neutrophils
- Glomerulosclerosis usually develops as a secondary process caused by nephron loss.

12. Microscopic of Ch.PN

13. Ch. PN. Thyroidization

14. Complication
-Secondary hypertension.
-proteinuria.
-Chronic renal failure.

15. Other types of renal infection
-Pyaemia
-Tuberculosis.
It secondary TB. due to hematogenous spread of infection, usually from the lung or ascending infection from TB of the genitourinary system.
TB pyelonephritis or military TB
Gross:
It is often bilateral, involving the medulla with replacement of the papillae by caseous material.
Microscopic: Caseating tuberculous granulomatous inflammation.

16. 2-Drug-induced interstitial nephritis
1-Acute Drug-Induced Interstitial Nephritis:
Sulphonamides, rifampicin, penicillin, thiazides, NSAIDs, allopurinol
Pathogenesis:
immunologic reaction or hypersensitivity reaction type I mediated by IgE and cell-mediated immune reactions to tubular cells or their basement membranes.
T cell-mediated (type IV) hypersensitivity reaction.
Clinically: begins after 15 days after exposure as fever, eosinophilia , rash and renal abnormality.
MSC: interstitial oedema and inflammatory cell infiltrate( lymphocytes,macrophages, eosinophils and PNL.
. Mainly in the medulla.Tubulitis and tubular necrosis.
Withdrawal of the drug leads to recovery.

17. 2- Chronic drug induced interstial nephritis( analgesic nephropathy):
large quantities of Phenacetin - containing analgesics may develop chronic interstitial nephritis, often associated with papillary necrosis.
Pathogenesis:
.Aspirin inhibits the vasodilatory effects of prostaglandin, predisposing the papilla to ischemia.
Thus, the papillary damage may be caused by a combination of direct toxic effects of phenacetin as well as ischemic injury to both tubular cells and vessels.
Clinical course: chronic renal failure, hypertension, and anemia

18. Acute drug induced TIN tubuloint

19. Chronic drug induced TIN

20. B-Acute tubular necrosis
Def: destruction of tubular epithelial cells with acute suppression of kidney function. It is reversible renal lesion.
Types
Toxic ATN
-poisons as Mgcl,
CCl4,Phosphorus,
&insecticides
-Drugs e.g. gentam
,amphotricin B
Anoxic(ischemic) ATN:
-Mismatched biood trasfusion
-Shock &severe hypotension
-Severe trauma ,burns

21. Acute tubular necrosis

22. Acute tubular necrosis

23. Vascular diseases of the kidney 1-Renal artery stenosis
Cause:-Atheromatous plaque.
-Fibromuscular dysplasia.
Effects: secondary hypertension(2-5%),due to renin production.
2-Infarcts
Presented by painless hematuria.
Causes:-Embolism Thrombosis on top AS

24. Atheromatous plaque

25. Thrombosed renal artery

26. Infarct of the Kidney

27. Infact kidney

28. Infarction of The kidney

29. 3-Senile atherosclerotic kidney
Grossly:
-Both kidneys are reduced in size.
-The outer surfaces show depressions due to scarring
-The renal artery is atheromatous.
MSC:
-Wedge-shaped areas of fibrosis.
-Hyalinized glomeruli.
- Tubules.are replaced by fibrous tissue

30. Atherosc.of the aorta and kidneys

31. Aortic Aneurysm with thrombus and senile kidneys

32. Atherosclerotic kidney
Atherosclerotic renal artery
Atherosclerotic kidney

33. Atheromatous plaque

34. A-Benign nephrosclerosis
4-Hypertension
A-Benign nephrosclerosis
Microscopic;
-Hyaline arteriolosclerosis
-Fibroelastic hyperplasia of large arteries
-Diffuse ischemic atrophy of the nephron
Grossly;
-Both kidneys are reduced in size (contracted)
-Granular outer surface
-Loss of demarcation between cortex and medulla

35. B. Nephrosclerosis

36. Arteiolosclerotic kidney

37. Arteriolonephrosclerosis

38. Benign nephrosclerosis

39. Benign Nephrosclerosis

41. B-Malignant nephrosclerosis
Microscopic:
-Fibrinoid necrosis
-Smooth muscle proliferation and duplication of basement
membrane ( onion-skin appearance)
-Necrotizing glomerulitis
Grossly:
-Enlarged kidney with peticheal hge

42. Fibrinoid necrosis in malignant hypertension

43. Malig. Nephrosclerosis. Onion –skin appearance

44. 5-Bilateral cortical necrosis 6-Necrosis of renal papillae
Rare lesion
Cause; ischemic as in toxemia of pregnancy or severe infections such as pneumonias and diphtherias
Gross; yellow cortex of both kidneys
MSC: Coagulative necrosis
6-Necrosis of renal papillae
Cause :ischemic necrosis due to PN, with DM, excess phenacetin and chronic alcoholism

45. Cortical necrosis

46. Necrosis of renal papillae

47. Necrotizing papillitis

48. Necrosis of renal papillae