常用肾脏功能实验室检测

1、肾功能检查ASSESSMENT OF RENAL FUNCTION山东大学刘运芳提要 Urine Tests: Cheap and convenient; For screening and following Renal Functions Immunological Test Imaging Examination Renal Biopsy3When or for What Kidney diseases or injuries Other diseases induced kidney function injuries Diabetes mellitus Hypertension Sh

2、ock or extensive burn Auto-immunological diseases Drug toxicity 4Structure of Kidney5肾单位肾单位集合管集合管肾小体肾小体肾小管肾小管肾小球肾小球肾小囊肾小囊近曲小管近曲小管远曲小管远曲小管髓袢髓袢GLOMERULAR FUNCTION ASSESSMENT6Structure and FunctionGFR: the volume of fluid filtered from the glomerular capillaries into the Bowmans capsule per unit time12

3、0-160ml/min120-160ml/minContents Serum Creatinine (sCr) & Serum urea (SU) Creatinine Clearance Rate, Ccr Cystatin C Microalbumin (MA) 、 Transferrinuria (TRU)、uric acid、urine IgSerum Creatinine (sCr)Endogenous a waste product produced by muscle metabolism CreatinineExogenous Come from foods, such

4、 as meat, fish, coffee, tea, etc.9Serum Creatinine (sCr) A small molecule, filtrated by glomerular completely, and not reabsorbed by tubule sCr: rise if the filtering of the kidney is deficient, Normal Value: Serum Cr: male: 44-132mol/L female: 70-106mol/L10Stage of renal failure (male)11445mol/L178

5、mol/L707mol/LStage 5 (Uremia)ScrClinical Significance of sCr increase12 rise only with marked damage to nephrons filtrationSerum urea (SU)also named as BUNInfluence factorsProtein intakeProtein degradationLiver functionGlomerular filtrationNormal value:Adults: 1.8-7.1mmol/LChildren or infants: 1.8-6

6、.5mmol/L13Urea or ornithine cycle in liverClinical Significance of SU Renal damage: Chronic renal failure Compensatory stage: SU9mmol/L Failure stage: SU20mmol/L Uremia: SU28.6mmol/L Acute renal disease14Clinical Significance Physical: ：high protein diet ：pregnancy Pre-renal: High fever, Shock, Uppe

7、r gastrointestinal hemorrhage, extensive burn，severe trauma Post-renal: Obstruction in urinary tract15SU/Cr ratio: BUN: 7-20 mg/dLUrea: 2.5-10.7 mmol/LsCr: 0.7-1.2 mg/dLsCr: 70-106 mol/LBUN:CrUrea:CrLocation20:1100:1Pre-renal10-20:140-100:1Normal or Post-renal10:140:1Intra-renalCreatinine Clearance

8、Rate, Ccr Definition：Ccr is the volume of blood plasma with creatinine that is cleared by kidneys per unit time. 即：单位时间内,肾脏可全部清除多少毫升血浆中的肌酐vNormal value： 80-120 ml/min1.73m2Clinical Significance of Ccr Physiological ： related with sports, diets, age Pathological decrease Sensitive for kidney injuryGF

9、R50ml/min80ml/minStage 4 (Failure stage)Stage 3 (De-compensatory stage) Stage 2 (Compensatory stage)Stage 1 (Normal function)10ml/min Stage 5 (Uremia)CCrFor treatmentStage IIobservation, control of blood pressure.Stage IIIa(30-40ml/min) limited protein diets, treatment of complication, diuretic(30ml

10、/min) diuretic is not available 20Stage IV combine treatment, planning for end-stage failure Stage V replacement therapy, transplantation or dialysis Stage of kidney impairementCcr （ml/min)sCr(umol/L)SU(mmol/L)Compensatory stage 80-501779Decompensatory stage 50-20178-1449-20Renal failure 20-10445-70

11、720-28.6end-stage renal failure (uremia)70728.6 Expressed in all nucleated cells, encoded by house keeping gene Low molecular weight, Filtrated freely through glomerulus Concentration in serum or plasma is determined by GFRCystatin CCystatin C better than creatinine in predictingCystatin C better th

12、an creatinine in predicting优点vHigh sensitivity：better than Ccr High specificity：not influenced by acute phase reaction, activities, gender and age, et al. Used widely: for renal transplantation status for monitoring GFR in nephrotoxic drug therapy for acute and chronic kidney diseases including a di

13、abetic nephropathy Operated easilyTESTS OF TUBULAR FUNCTION26Function of renal tubular重吸收：水、电介质、小分子蛋白重吸收：水、电介质、小分子蛋白 葡萄糖、氨基酸葡萄糖、氨基酸肾单位肾单位集合管集合管肾小体肾小体肾小管肾小管肾小球肾小球肾小囊肾小囊近端小管近端小管远端小管远端小管髓袢髓袢尿液稀释、浓缩尿液稀释、浓缩远端肾单位远端肾单位TESTS OF PROXIMAL TUBULAR FUNCTION28Tests of Proximal tubular Function 2-microglobulin 1-

14、microglobulin Retinol-binding protein, RBP N-acetyl-D-glucosaminidase, N-NAG Fraction of urine natrium excretion, FeNa2-microglobulin, 2-MG Present on all nucleated cells, especially on lymphocytes, and stable in blood Small protein, freely filtrated by glomeruli Almost reabsorbed by tubules complet

15、ely Threshold of reabsorption:5mg/LNormal value: Urine：0.3mg/LClinical Significance of 2-MG Serum 2-MG ： GFR :when Ccr80ml/min，more sensitive than Scr 恶性肿瘤、炎性疾病（肝炎、类风湿关节炎等） Reabsorption function of proximal tubules： urine 2-MG increase (blood 2-MG5mg/L) Acute and chronic pyelonephritis Drug or toxin

16、 induced tubular necrosisClinical Significance Evaluation for transplant kidney function Urine 2-MG，implied graft rejectionserum 2-MG: help for sub-clinical rejection of grafts肾移植虽有少尿，但血2-MG下降者提示预后良好。 1-microglobulin, 1-MG Small glycoproteins, synthesized in liver Freely filtrated through glomeruli

17、Almost reabsorbed by proximal tubules completelyNormal value: Urine：15mg/24hClinical Significance of 1-MGvDecrease: severe hepatitis and hepatic necrosis Serum 1-MG ： GFR : when Ccrlower，locationFraction of urine natrium excretionNatrium: freely filtrated through glomeruli and 99% was reabsorbed by

18、proximal tubulesNormal values: FeNa: 1%crNaCCcrNacrNaU P PU FeNaClinical SignificancePre-renal：钠摄入过多或血容量下降 尿钠同时伴有血钠Reabsorption damage: 急性肾小管坏死 尿钠 ，但血钠不高Differential diagnosis of azotemia Prerenal : FeNa 1%Summary 2-microglobulin 1-microglobulin Retinol-binding protein, RBP reabsorption function N-a

19、cetyl-D-glucosaminidase, N-NAG kidney toxicity damage Fraction of urine natrium excretion, FeNa differential diagnosis of pre-renal and intra-renal azotemiaTESTS OF DISTAL TUBULAR FUNCTION42Renal concentration functionMosenthals testAlso as : Circadian urine specific gravity (SG) test Normal intake (water500-600ml), no extra water Empty bladder at 8 am in the morning Detect the volume and SG of the urine every 2 hours from 10am to 8pm, and morning urine of next dayNormal Values volume： 24h total volume: 10002000ml； 12h overnight urine: 34 1 SG