常用肾脏功能实验室检测

诊断学,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 followingRenal FunctionsImmunological TestImaging ExaminationRenal Biopsy,3,When or for What,Kidney diseases or injuriesOther diseases induced kidney function injuries Diabetes mellitusHypertensionShock or extensive burnAuto-immunological diseasesDrug toxicity,4,Structure of Kidney,5,肾单位,集合管,肾小体,肾小管,肾小球,肾小囊,近曲小管,远曲小管,髓袢,肾小球功能检查,Glomerular function assessment,6,Structure and Function,GFR: the volume of fluid filtered from the glomerular capillaries into the Bowmans capsule per unit time120-160ml/min,Contents,Serum Creatinine (sCr) & Serum urea (SU)Creatinine Clearance Rate, CcrCystatin CMicroalbumin (MA) 、 Transferrinuria (TRU)、uric acid、urine Ig,Serum Creatinine (sCr),Endogenous a waste product produced by muscle metabolism,9,Serum Creatinine (sCr),A small molecule, filtrated by glomerular completely, and not reabsorbed by tubulesCr: rise if the filtering of the kidney is deficient, Normal Value: Serum Cr: male: 44-132mol/L female: 70-106mol/L,10,Stage of renal failure (male),11,Scr,Clinical Significance of sCr increase,12,rise only with marked damage to nephrons filtration,Serum urea (SU),also named as BUN,Influence factorsProtein intakeProtein degradationLiver functionGlomerular filtrationNormal value:Adults: 1.8-7.1mmol/LChildren or infants: 1.8-6.5mmol/L,13,Urea or ornithine cycle in liver,Clinical Significance of SU,Renal damage:Chronic renal failureCompensatory stage: SU9mmol/LFailure stage: SU20mmol/LUremia: SU28.6mmol/LAcute renal disease,14,Clinical Significance,Physical: ：high protein diet ：pregnancyPre-renal:High fever, Shock, Upper gastrointestinal hemorrhage, extensive burn，severe traumaPost-renal:Obstruction in urinary tract,15,SU/Cr ratio:,Creatinine Clearance 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,Normal value： 80-120 ml/min1.73m2,Clinical Significance of Ccr,Physiological ： related with sports, diets, agePathological decreaseSensitive for kidney injuryGFR50%时Ccr50ml/min,Stage of renal failure,19,CCr,For treatment,20,combine treatment, planning for end-stage failure,Stage of kidney impairement,Expressed in all nucleated cells, encoded by house keeping geneLow molecular weight, Filtrated freely through glomerulusConcentration in serum or plasma is determined by GFR,Cystatin C,Cystatin C better than creatinine in predicting,Cystatin C better than creatinine in predicting,优点,High sensitivity：better than CcrHigh specificity：not influenced by acute phase reaction, activities, gender and age, et al.Used widely: for renal transplantation statusfor monitoring GFR in nephrotoxic drug therapyfor acute and chronic kidney diseases including a diabetic nephropathyOperated easily,肾小管功能检查,Tests of tubular function,26,Function of renal tubular,重吸收：水、电介质、小分子蛋白 葡萄糖、氨基酸,肾单位,集合管,肾小体,肾小管,肾小球,肾小囊,近端小管,远端小管,髓袢,尿液稀释、浓缩,远端肾单位,近端肾小管功能检查,Tests of proximal tubular function,28,Tests of Proximal tubular Function,2-microglobulin1-microglobulinRetinol-binding protein, RBPN-acetyl-D-glucosaminidase, N-NAGFraction of urine natrium excretion, FeNa,2-microglobulin, 2-MG,Present on all nucleated cells, especially on lymphocytes, and stable in bloodSmall protein, freely filtrated by glomeruliAlmost reabsorbed by tubules completelyThreshold of reabsorption:5mg/L,Normal value: Urine：0.3mg/L,Clinical 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 pyelonephritisDrug or toxin induced tubular necrosis,Clinical Significance,Evaluation for transplant kidney functionUrine 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 liverFreely filtrated through glomeruliAlmost reabsorbed by proximal tubules completely,Normal value: Urine：15mg/24h,Clinical Significance of 1-MG,Decrease: severe hepatitis and hepatic necrosisSerum 1-MG ：GFR : when Ccrlower，location,Fraction of urine natrium excretion,Natrium: freely filtrated through glomeruli and 99% was reabsorbed by proximal tubulesNormal values:FeNa: 1%,Clinical Significance,Pre-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 azotemiaPrerenal : FeNa 1%,Summary,2-microglobulin1-microglobulinRetinol-binding protein, RBP reabsorption functionN-acetyl-D-glucosaminidase, N-NAG kidney toxicity damageFraction of urine natrium excretion, FeNa differential diagnosis of pre-renal and intra-renal azotemia,远端肾小管功能检查,Tests of distal tubular function,42,Renal concentration function,Mosenthals testAlso as : Circadian urine specific gravity (SG) testNormal intake (water1.018the gap of the highest and the lowest 0.009,Clinical Significance,Impairment in distal tubules：Early stage