Understanding Nephrology: Functions and Diseases of the Kidney

1. Nephrology introduction L1

3. Function of the kidney • 1-regulatof ion body water and electrolyte. • 2-excretion of waste product . • 3-regulation of acid base balance. • 4-regulation of erythrocyte production. • 5-regulation of vit. D production. • 6-regulation of blood pressure (short & long term)

4. Renal physiology • Normal renal function depend on : • 1-Glomerular filtration • 2-tubular function.

6. Glomerular filtration start during 3 rd month of gestation and fetal urine production contribute to amniotic fluid volume so any renal anomalies are often associated with reduced amniotic fluid volume

7. Proximal tubules : isotonic re absorption of glomerular filtrate so 2/3rd will re absorb here ( glucose , AA,K, phosphate and 75% of HCO3 will re absorb in the proximal tubules • *Loop of henle = contribute to 25% of absorption of Nacl

8. *Distal tubules and collecting ducts = water permeable and contribute to urine dilution which is primary site of ADH which produce concentrated urine and active H ion secretion which responsible for final acidification of urine

9. Renal diseases : 1-primary dysfunction ( in the kidney it self 2-secondary dysfunction ( systemic illness alter renal function )

10. Common renal manifistation1- in neonate

11. Child &adolescent

12. *polyuria >1500ml/day • *oliguria –UOP<1ml/kg/hr or <300 ml/m2/day • *Anuria _UOP<1 ml/kg/day

13. Investigation of renal disease • A-urinalysis • Urine collection • a-mid stream urine within 1 hr after void • b- clean catch urine in symptomatic and asymptomatic pat. • c-catheterization -febrile pat. usually have 50,000 CFU • d-supra pubic aspiration growth in any no. is +ve

14. 1 - turbidity can be normal due to crystal formation uric. acid give acidic urine & phosphate crystals give alkaline urine • 2- PH use ph meter 5-7 in neonate &4.5 -8 thereafter or use dipstick

15. 3-specific gravity 1.002-1.030 need 15 ml of urine use hydrometer 4-tests for infection (pus cell) all tests should be confirmed with culture.

16. a- dip stick • b –nitrite test .reduction of dietary nitrate by urine m.o(E • coli, klebsialla,proteus) • c-leukocyte esterase test detect esterase released from • broken down leukocyte • d- urine gram stain screen for UTI

17. 5-test for protein; up to 150 mg /day can be normal • The test should be for 24 hr collection • a-dip stic ck (1+=30.) (++ 100)(+++300 • b-- sulfa salicylic acid SSA 0,5 ml of 20% of SSA add to 5 ml of urine and examine for turbidity • c- protein /creatinin ratio >0.2 suggest protein uria

18. Types of protein uria • A-glomerukar proteinuria • 1- transient proteinuria • 2- orthostatic proteinuria • 3-proteinuria secondary to glomerulopathies(structure or function)

19. B- tubular proteinuria presence of low molecular wt. protein in urine such as fanconi`s syndrome

20. 6- test for sugar • . renal threshold of sugar up to 180 mg/dl glucosuria suggestive and not diagnostic for DM • a- dipstick specific for glucose false +ve in ascorbic acid

21. b- clinitest tablet for all reducing substances (5 drop of urine and 10 drop water and 1 tab.) and compare color with standard - • 7- test for ketone , ketone uria suggest ketoacidosis( DM or catabolism )

22. 8- hemoglobin and myoglobin ( dipstick and microscopy) • 9- bilirubin and urobilinogin dip stick 10- sediment using light microscopy ( well centrifuged urine examine for cell . cast crystals ,,,,,, etc )

23. B- blood ( renal function test ) mainly blood uria nitrogen and serum creatinin(7- 18mg/dl ,0.5-1.0 mg/dl respectively ) • C- imaging studies • 1- plain x ray ,routinely in UTI • 2- U/S in (cystic, hydronephrosis,perirenal abscess. ````````````````Pyonephrosis, severly ill toxic pat. Acute Pyelonephritis .no response to AB)

24. 3-intravenous urography • 4- VCUG(rule out reflux ,posterior urethral valve , any • Male with UTI,febrile pat. With UTI,school age • Children with UTI 2 or more attack) • 5--DMSA scan( reflex, renal scaring )

25. Congenital anomalies of the kidney • 1- renal agenesis incompatible with life (potter syndrome) death occur shortly after birth due to pulmonary hypoplasia • 2-unilateral renal agenesis may associated with single umbilical artery

26. 3- renal dysplasia and hypoplasia (present as neonatal abd. Mass)

27. Dysplasia is histological term (focal ,diffuse or segmentaly arranged primitive structures ) if cyst present called multicystic dysaplastic kidney and this differ from polycystic kidney

28. Polycystic is inherited disease (mainly autosomal recessive • Renal hypoplasia : small non dysplastic kidney

29. Anomalies of shape and position • Ectopic kidney (pelvis ,iliac , thoracic or contralateral position (horse shoe kidney).

30. Nephrotic syndrome(nephrosis)L2 • Definition :protein uria >40 mg/m²/hr. • Definition of NS; • 1-heavy proteinuria >1 g/m2/day or >2 g in 24 urine collection • 2-hypoproteinemia s .albumine <2.5 g/dl • 3-hypercholesterolemia >250 mg/dl (increase synthesis of lipoprotein and decrease lipase due to hypoalbumenemia ) • 4-edema ( appear when albumin below 2.5 g /dl )

31. Protein charge • At physiological pH, most proteins are negatively charged • Since the basement membranes are also negatively charged, most proteins are retained

32. mechanism of edema • (1-)hypoalbumenemia and protein loss in urine lead to decrease plasma oncotic pressure so fluid shift from intravascular to interstitial space • ( 2-)activation of rennin angiotensin aldosterone system secondary to reduction in Intravascular volume and decrease in • renal perfusion so stimulate distal tubular reab- Sorption of Na.

36. ( 3-)ADH secondary to reduction in intravascular volume so enhance water reabsorption In the collecting • ducts .

37. Etiology • 90% idiopathic • 85% minimal change NS • 5%mesengeal proliferation • 10% focal sclerosis

38. Pathophysiology • Increase in glomerular capillary wall • permeability (unknown) may be due to • loss of negatively charged glycoprotein • within capillary wall

39. Idiopathic NS (minimal change NS) typical type • 90% of nephrosis in children • 2:1 in male

40. Normal urine protein: 150mg/day • About 15-20 mg of the normal urine protein is albumin • Urine dipsticks detects urine albumin >300mg/day

41. Pathology • E microscope show reduction of epithelial cell foot process • 95 % are steroid sensitive

42. Clinical features : • Age 2-6 yrs may seen in second half of the first year • Edema :usually presented around the face , eyes ,then extended to lower extremities , pitting in nature then generalize and may associated with wt. gain

43. Anorexia , abd. Pain diarrhea are common manifestation • Hypertension is uncommon

44. diagnosis • Urinalysis: reveal 3+……4+ protein • Microscopical hematuria may present • Macroscopical = is rare • Renal function normal or low • Decrease creatinin clearance

45. Protein in 24 hr. collection may exceed 2 g/24 hr. • s. cholesterol and triglyceride are high • s. albumin level <2g/dl • total s calcium low ( albumin bound fraction ) • C3 level normal

46. Protein slectivity = • If ratio <0.2 is high selective protein urea and good steroid responsiveness and vise versa Urinary IgG/plasma IgG Urinary transferrin /plasma transferrin

47. Proteinelectrophoresis albumin alpha1 Globulin Beta alphaa2 Gama

48. Complication : • 1-infection (streptococcal pneumonia and G –ve bacteria ) • -loss of Ig in urine • - edema is good culture media • -Immune suppression ( steroid) • -T cell abnormality • -Loss of compliment in urine (properdin factor B) • -Loss of transferin

49. Types ; • A. spontaneous peritonitis • B .UTI

50. 2-thrombosis ( arterial and venous) • a-decrease plasma level of antithrombin 111 • b-increase platelet aggregation • c- deficiency of factor 9, 11, 12 • d- increase level of certain coagulative factors (5. 8).