1. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 25 Disorders of Renal Function

2. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Cystic and Obstructive Disorders Cystic disease of the kidney –Simple and acquired renal cysts –Medullary cystic disease –Autosomal dominant polycystic kidney disease Obstructive disorders –Hydronephrosis –Renal calculi

3. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Consequences of Dilatation of Renal Tubules or Tract Expansion of the kidney with urine (hydronephrosis) –Increased pressure inside the renal capsule –Compartment syndrome compresses blood vessels inside kidney –Renal ischemia Stasis of urine –Risk of infection –Stones

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5. Question Tell whether the following statement is true or false: Hydronephrosis is categorized as a disorder of glomerular function.

6. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer False Hydronephritis is caused by a urinary obstruction, so it is considered an obstructive disorder. The glomerulus is not involved.

7. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Renal Calculi Saturation theory: urine is supersaturated with stone components Matrix theory: organic materials act as a nidus for stone formation Inhibitor theory: a deficiency of substances that inhibit stone formation Four types of kidney stones: –Calcium stones (i.e., oxalate or phosphate) –Magnesium ammonium phosphate stones –Uric acid stones –Cystine stones

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9. Urinary Tract Infections Bacteria usually enter through the urethra Host defenses include: –Washout phenomenon –Protective mucus –Local immune responses and IgA –Normal bacterial flora

10. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Scenario Mr. K is paraplegic… When in the hospital, he had a catheter Now he has a high fever and complains of joint and back pain He has pyuria and reports urgency BUN is 78 mg/dL PCR is 4.7 mg/dL Question: What complication are you most worried about? Why?

11. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Tell whether the following statement is true or false: UTIs are usually caused by a virus.

12. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer False UTIs are most often caused by bacteria that enter through the urethra (most common) or the bloodstream.

13. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Glomerular capillaries and Bowman’s capsule are both made of epithelial cells sitting on a basement membrane They are so tightly attached to each other that they share one basement membrane The epithelial cells of Bowman’s capsule stand up from the basement membrane on foot processes, leaving pores between the feet for filtration

14. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Glomerular Damage Proliferative: number of cells increase Sclerotic: amount of extracellular matrix increases Membranous: thickness of glomerular capillary wall increases All can decrease the efficiency of filtration Allow blood cells, lipids, or proteins to pass into the urine

15. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of Glomerular Function Nephritic syndromes –Proliferative inflammatory response Nephrotic syndrome –Increased permeability of glomerulus Mixed nephritic and nephrotic responses Chronic glomerulonephritis Glomerular lesions associated with systemic disease

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17. Nephritic Syndromes Proliferative inflammatory response –RAA pathway activated; hypertension Inflammatory process damages the capillary wall –Red blood cells escape into the urine Hematuria with red cell casts –Hemodynamic changes decrease the GFR Azotemia (presence of nitrogenous wastes in the blood), oliguria

18. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Nephrotic Syndrome Other proteins lost in urine: Immunoglobulins and complement  immune suppression Clotting and anticlotting proteins  thrombosis Proteins that carry other blood components  imbalances in blood components; altered drug dosages

19. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Tell whether the following statement is true or false: Nephritic syndromes are characterized by blood in the urine.

20. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer True Nephritic syndromes decrease the permeability of the glomerular capillary membrane, which results in hematuria, HTN, oliguria, and ↓ GFR.

21. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Scenario A woman has diabetes mellitus… She has severe edema and frothy, cola-colored urine She has difficulty breathing, with crackles in both lungs She just finished a course of antibiotics for strep throat She is also taking corticosteroids for lupus-related arthritis Question: What are three reasons for her renal problems?

22. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Scenario (cont.) A woman has diabetes mellitus and lupus and recently had strep throat… She has severe edema and frothy, cola- colored urine Question: The doctor says the only way to determine what has caused her glomerular disease is a renal biopsy. Why?

23. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Scenario (cont.) Urinalysis show that she is producing: –Urine with 500 mg protein/ day –Contains blood and RBC casts –High level of K+ Blood tests show: –Hypoalbuminemia –Slightly decreased K+ She has borderline hypertension Question: Does she have nephritic syndrome or nephrotic syndrome?

24. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Tubulointerstitial Disorders Acute tubular necrosis Pyelonephritis –Acute pyelonephritis –Acute hypersensitivity to drugs –Chronic pyelonephritis Drug-related nephropathies

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26. Malignant Tumors of the Kidney