Kidney

1. Kidney

2. Vascular diseases of Kidney 1.Hypertensive Renal Disease: Nephrosclerosis-Benign & Malignant 2.Thrombotic Microangiopathies: Childhood & Adult Hemolytic-Uremic Syndrome (HUS) Adult (female) Thrombotic Thrombocytopenic Purpura (TTP) Autoimmune Diseases Toxemia of pregnancy Severe bacterial infections. 3.Renal Artery Stenosis (RAS): Atherosclerotic or Fibromuscular dysplasia reversible hypertension 4.Renal Infarcts: Embolic or Thrombotic.

3. 1. Hypertension Most renal diseases cause HTN HTN has marked effects on the kidneys Benign Nephrosclerosis= hyaline arteriosclerosis Most are at risk for developing malignant hypertension Malignant Nephrosclerosis= Hyperplastic arteriolosclerosis Fibrinoid necrosis of arterioles Thrombotic Microangiopathy (Necrotizing Glomerulitis) ? renal blood flow therefore, ? renin -angiotensin system ? ?BP ? hypertension. Clinical: Neurological =Disoriented ? coma Eyes = Papilledema Renal = proteinuria, Hematuria & RF

4. Benign Nephrosclerosis Fine leathery granularity,

5. Benign Nephrosclerosis Hyaline change in small blood vessels

6. Malignant Nephrosclerosis Hyperplastic arteriolosclerosis (onion-skinning) Blood vessels have collagen deposits making the onion skinning appearance Notice how lumen gets very small

7. 2. Thrombotic Microangiopathies Common findings: Thrombosis in small vessels Microangiopathic hemolytic anemia (MHA) Thrombocytopenia Pathogenesis: Endothelial injury ? platelet aggregation? thrombosis Vasoconstriction ? ischemia ? necrosis A) Childhood Hemolytic Uremic Syndrome (HUS) E. coli (infected Hamburgers) Clinical: renal failure is prominent Intestinal bleeding, oliguria, Hematuria, MHA, HTN B) TTP = young females with High mortality

8. Fibrin Thrombi (Childhood HUS) Caused by DIC, HUS (E. coli 0157H7)

9. 3. RENAL ARTERY STENOSIS (RAS)

10. Fibromuscular Dysplasia Fibromuscular dysplasia

11. 4. Renal infarcts Branches of Renal artery - End arteries. MCC= MI and thromboembolism from Atrial Fibrillation Clinical: Asymptomatic or Large unilateral -May cause HTN Extensive bilateral -May cause RF

12. Renal Infarcts

13. Renal Infarcts

14. Kidney

15. Tubulo � Interstitial diseases 1. Acute Tubular Necrosis (ATN) 2. Pyelonephritis (PN) Acute Chronic 3. Acute drug-induced Interstitial Nephritis 4. Analgesic Abuse Nephropathy 5. Metabolic Tubulointerstitial Disease Urate Hypercalcemia Multiple Myeloma

16. 1. Acute Tubular Necrosis (ATN) Most serious but reversible kidney disease, Causes= next slide Pathology= destruction of tubular epithelial cells ?Acute suppression of renal function, urinary output <400 ml/day ATN ?ARF by mechanisms Tubular cell injury? Tubulo glomerular feed back Tubular obstruction by Hyaline or pigmented granular casts (Tamm-Horsfall proteins secreted by tubular epithelium) Back-leak of tubular fluid into the interstitial space (due to death of tubular cells) The outcome of all the above three is ?GFR (oliguria) Clinical Course= Three phases Initial phase= (first 36 hrs.), Dominated by the cause Maintenance phase= Oliguria & acute uremia Salt & water retention Hyperkalemia and metabolic acidosis. Rx � fluid & Electrolyte balance, dialysis Recovery phase=Polyuria & electrolyte loss Hypokalemia (give lots of fluids + K+ sparing diuretics) ?risk of infections BUN & creatinine levels return to normal

17. ATN- Causes

18. ATN Necrotic & Regenerating tubular epithelial cells

19. 2. Pyelonephritis (PN)= Bacterial infection of kidney Causes? chronic urinary tract infection Routes of bacterial entry into kidneys 1.Ascending Infection (MCC) by vesico-ureteral reflux (VUR) 2. Hematogenous Infection (septicemia) Helped by lower UT obstruction Pathology = Inflammation - renal parenchyma & pelvis Clinical= asymptomatic or cause severe flank pain & fever Lab= Bacteria, leukocytes & Casts High risk pts= DM, pregnancy & UT obstruction Complications = Necrotizing papillitis or papillary necrosis (papillary necrosis is seen in 4 conditions????) ( CT scan - best investigation) Pathologic types = Acute PN, Chronic PN

20. Acute Pyelonephritis = Neutrophilic exudate within tubules and renal substance kidney is almost unrecognizable Complications= papillary necrosis, Perinephric abscesses, Pyonephrosis, Scarring (Chronic Pyelonephritis) Chronic Pyelonephritis (CPN) = Chronic tubulointerstitial inflammation Characterized by= CRF & HTN Pathology = corticomedullary scars overlying dilated blunted calyces. Forms of CPN 1 Reflux nephropathy-associated type MCC of CPN MCC of reflux= Congenital intra-renal reflux With superimposed bacterial infection (E. coli). 2.Obstructive type predisposes to recurrent bacterial infections (E. coli) Course= Glomeruli undergo ischemic atrophy, total sclerosis with fine leathery granularity, shrunken. Finally Glomeruli disappears

21. Acute Pyelonephritis Neutrophilic exudate within tubules and renal substance � kidney is almost unrecognizable

22. Chronic Pyelonephritis (CPN)

23. Chronic Pyelonephritis (CPN)

24. 3 . Acute drug-induced interstitial nephritis Manifests 2-40 days after the start of Rx (methicillin, ampicillin, rifampicin, thiazides, NSAID, cimetidine, .... ) Clinical= Presents with fever, skin rash, hematuria, proteinuria, sterile pyuria, Eosinophilia= (allergic, parasitic and Drug reactions), azotemia, and acute RF Pathology = Eosinophils and mononuclear infiltrates & Patchy tubular necrosis Withdrawal of drug ? recovery 4. Analgesic Abuse Nephropathy = Chronic tubulointerstitial nephritis with papillary necrosis Caused by= Habitual intake of large doses Acetaminophen (Tylenol) ? directly damages cells Aspirin -vasoconstriction ? ischemia Pathology = papillary necrosis ( other causes???) Clinical= Presents with Polyuria, Nocturia, HTN, headache, GI symptoms, anemia, may develop UTI, may develop CRF Complications= ? risk for TCC (Transitional cell Carcinoma) - renal pelvis

25. Drug-induced interstitial nephritis

26. Analgesic Abuse Nephropathy Papillary necrosis

27. Analgesic Abuse Nephropathy Can slough off and obstruct urinary tract

28. 5. Metabolic Tubulointerstitial Disease Urate Nephropathy: form of: Acute RF (with cancer chemotherapy). Chronic RF (with gout & chronic lead poisoning). Hypercalcemia: cause RF by: Nephrolithiasis (causing UT obstruction). Nephrocalcinosis (causing renal atrophy). Multiple Myeloma: Acute or chronic RF result of Bence - Jones & Tamm-Horsfall proteinuria, Hypercalcemia & Nephrotoxic drugs Cast nephropathy Amyloid deposits- Light-chain nephropathy -AL

29. MULTIPLE MYELOMA (plasma cells) Note tubular casts

30. Kidney

31. OBSTRUCTIVE UROPATHY (HYDRONEPHROSIS) Characterized by: Unrelieved UT obstruction Leads to renal atrophy, with dilatation of the renal pelvis and calyses ? �Hydronephrosis� � all widened due to obstruction and distension in pelvis. Still have glomerular filtration ? increase in urine load ? distension If Bilateral ? CRF

32. HYDRONEPHROSIS Causes are: Congenital anomalies (vesicoureteral reflux, urethral valves, meatal stenosis) Urinary calculi Benign prostatic hypertrophy Tumors Pregnancy Neurogenic bladder Inflammatory strictures (including retroperitoneal fibromatosis).

33. HYDRONEPHROSIS �Hydronephrosis� � all widened due to obstruction and distension in pelvis

34. Kidney