肾小球

nullLaboratory investigation of renal function*prepared by xuejingwangLaboratory investigation of renal functionDepartment of Clinical Laboratory Peking University First Hospital Xue jing WangContents*prepared by xuejingwangContentsRenal physiology and function Laboratory investigations of renal function glomerulus 肾小球 renal tubule 肾小管 assessment and monitoring for early renal injury How to select tests Renal anatomy and physiology*prepared by xuejingwangRenal anatomy and physiologyRenal anatomy*prepared by xuejingwangRenal anatomyA renal vein B renal artery C ureter 输尿管 D cortex E pelvis 肾盂 F renal capsule 包囊null*prepared by xuejingwangGlomerulus Loop of Henle Collecting tubuleNephron 肾单位*prepared by xuejingwangNephron 肾单位Glomerulus Proximal convoluted tubule 近曲小管 Henle’s loop Distal convoluted tubule Collecting duct Peritubular capillary 管周毛细血管Urine production*prepared by xuejingwangUrine productionRenal blood flow*prepared by xuejingwangRenal blood flowRenal functions*prepared by xuejingwangRenal functionsGlomerulus: Removal of metabolic waste products; Removal of foreign chemicals Proximal convoluted tubule: Reabsorption of useful substance such as glucose, low molecular protein, amino acid etc, excretion of unwanted substance Henle’s loop: countercurrent multiplier system （逆流倍增系统), help to concentrate and dilute urine Distal convoluted tubule and collecting duct: Regulation of water, inorganic ion and acid-base balance Others: endocrineGlomerulus function examination *prepared by xuejingwangGlomerulus function examination Glomerulus filtration membrane*prepared by xuejingwangGlomerulus filtration membraneEndothelium 内皮细胞 Basement membrane Foot processesSize barrier 分子屏障*prepared by xuejingwangSize barrier 分子屏障LMWP: <50kD RBP, a1-MG,B2-MG MMWP:50-70kD albumin, transferrin HMWP:>90kD Ig, TH proteinCharge barrier（电荷屏障）*prepared by xuejingwangCharge barrier（电荷屏障）Sulfate heparin(硫酸肝素） Sialytic acid（唾液酸）null*prepared by xuejingwang Glomerular filtration rate(GFR，肾小球滤过率): the volume of blood filtered per minute 单位时间内从肾小球滤出的血浆量 Renal Clearance（肾脏清除率）: the volume of plasma from which a measured amount of substance can be completely eliminated into urine per unit of time 每分钟肾脏能将多少毫升血浆中的某物质通过尿液加以清除 C=UV/P null*prepared by xuejingwangA glomerulus filtration C tubule reabsorption D renal plasma flowSubstances reabsorption*prepared by xuejingwangSubstances reabsorptionCreatinine and Creatinine Clearance 肌酐和肌酐清除率*prepared by xuejingwangCreatinine and Creatinine Clearance 肌酐和肌酐清除率Endogenous metabolic product synthesized with a constant rate, metabolite of phosphate creatine, which provides energy to muscle. Freely filtered through glomerular Slightly secreted by proximal tubule Stable serum level under general situation Readily available colorimetric method for measurement Formula for creatinine clearance(Ccr)*prepared by xuejingwangFormula for creatinine clearance(Ccr) Ucr（μmol/L） Ccr（ml/min）= –––––––––––– × urine volume（ml/min） Scr（μmol/L） ×1.73/A logA（m2）＝0.425log(weight)kg＋0.725log(height)cm－2.144 Ccr: creatinine clearance Ucr: urine creatinine concentration Scr: serum creatinine concentration A : body surface areanull*prepared by xuejingwangReference interval: age, sex Clinical significance: a sensitive test help to judge filtration function help to instruct drug administration Precaution sample collection and storage Ccr is higher than GFR in renal failure patients( proximal tubule secretion)Urea 尿素*prepared by xuejingwangUrea 尿素main metabolite product of protein(about 45% of NPN 非蛋白氮) freely filtered by glomerulus 40% reabsorbed by tubules Reference interval:2.8~7.1 mmol/L Clinical significance pre-renal factors renal disease: not a sensitive markerUric Acid 尿酸*prepared by xuejingwangUric Acid 尿酸metabolite of nucleic acid fully filtered by glomerular completely reabsorbed by tubule Clinical significance gout 痛风 hyper-metabolism of nucleic acid renal diseaseCr,Urea and Ccr*prepared by xuejingwangCr,Urea and Ccrnull*prepared by xuejingwangSerum Cystatin C 胱氨酸蛋白酶抑制剂C MW13.4Kd, pI9.3, 120aa, produced by all the cells Constantly generate, not affected by inflammation and neoplasm Electrophoresis band locates at post-r region Now has automatic measurement assay Cystatin C in healthy body*prepared by xuejingwangCystatin C in healthy bodyBefore 5 months, concentration of cystatin c in baby is obviously higher than that of adult, due to the unmatured glomerular filtration function After 5 months, a sharp decrease could be seen showing a constant serum level, same as that of adult.Ccr and Cystatin C*prepared by xuejingwangCcr and Cystatin CReference interval Clinical significancenull*prepared by xuejingwangTubule function examination*prepared by xuejingwangTubule function examinationnull*prepared by xuejingwangProximal convoluted tubule function examination Distal convoluted tubule function examination Diagnostic test for renal tubule acidosisProximal convoluted tubule function test*prepared by xuejingwangProximal convoluted tubule function testReabsorption tests Excretion testsReabsorption test*prepared by xuejingwangReabsorption testtubule maximal glucose reabsorptive capacity test (TmG) 肾小管葡萄糖最大重吸收量试验 Method: burden test Reference interval: 330-440mg/min Clinical significance: Excretion test*prepared by xuejingwangExcretion testphenol sulfonphothalein(PSP) excretion test 酚红排泄试验 paraaminohippuric acid excretory capacity test(TmPAH) 对氨基马尿酸最大排泌量试验Distal convoluted tubule test concentration and dilution tests osmolality electrolytes analysis*prepared by xuejingwangDistal convoluted tubule test concentration and dilution tests osmolality electrolytes analysisConcentration and dilution test Mosenthal test *prepared by xuejingwangConcentration and dilution test Mosenthal test Method Reference interval 24 hours urine volume: 1L to 2L daytime/nighttime: >=2:1 maximal gravity difference:>0.009 Clinical significance:concentration dysfunction urine volume above 2L nighttime urine increase fixative urine gravity Urinary osmolality test*prepared by xuejingwangUrinary osmolality testconcept of osmolality: how many particles existing in a solution, have nothing with its size, charge and kind. Osmolality:mass /kg, Osmolarity:volume /L 质量渗摩尔 体积渗摩尔 Freezing point depression method(冰点下降法） Reference interval urine osmolality: 50~1200mOsm/kg H2O, average 800 mOsm/kg H2O plasma osmolality: 275~305 mOsm/kg H2O Uosm/Posm: 3~4.5 : 1 Clinical signifance： distal nephron dysfunction null*prepared by xuejingwangOsmotic clearance test: how much solute in plasma can be eliminated in a given time. Cosm=Uosm/Posm*V Solute-free water clearance test: how much water un-wanted in plasma can be eliminated in a given time. CH20=V-CosmDiagnostic tests for renal tubule acidosis (self-study)*prepared by xuejingwangDiagnostic tests for renal tubule acidosis (self-study)Typing of tubule acidosis Urinary acidification function test Ammonium chloride loading test(acid loading test) Bicarbonate absorption and secretion test(base loading test)Assessment and monitoring for early renal injury*prepared by xuejingwangAssessment and monitoring for early renal injuryUrinary marker for early injuries*prepared by xuejingwangUrinary marker for early injuriesGlomerular markers*prepared by xuejingwangGlomerular markersFunctional markers(commonly used) Structural markers(in research)Microalbumin 微量白蛋白*prepared by xuejingwangMicroalbumin 微量白蛋白MW67000 dalton, negtive charge Cannot be filterred too much normally Elevated in early glomerular damage Reference interval:<30mg/24h etc. Clinical significance early glomarular damage caused by various diseases, such as DM, hypertension,pregnancyTransferrin 转铁蛋白*prepared by xuejingwangTransferrin 转铁蛋白MW76500 dalton Negtive charge Cannot be filterred by glomerular normally Referance interval:<2 mg/L Clinical significance: same as that of albuminStructural markers*prepared by xuejingwangStructural markersType 4 collagen Phosphate heparin Sialytic acidTubular markers*prepared by xuejingwangTubular markersFunctional markers Structural markersa1-microglobulin a1微球蛋白*prepared by xuejingwanga1-microglobulin a1微球蛋白MW30000 dalton Freely pass through glomerulus Completely reabsorbed by proximal tubule Reference interval: <12.5 mg/L Clinical significance: NAG N-乙酰-B-D-氨基葡萄糖苷酶*prepared by xuejingwangNAG N-乙酰-B-D-氨基葡萄糖苷酶MW140000 dalton Abundant in proximal tubule cell Lysosomal enzyme 溶酶体酶 Easily attacked and released by various factors( biological and chemical toxic, immunol factors, etc) Reference interval: Clinical significance: Other markers*prepared by xuejingwangOther markersFunctional markers Retinol binding protein 视黄醇结合蛋白 Protein 1 Structural markers AAP: 丙氨酸氨基肽酶 MW280000 dalton, brush border enzyme 刷状缘酶 r-GT: r谷氨酰转肽酶 brush border enzyme刷状缘酶 B-Glu: B-葡萄糖苷酸酶 lysosomal enzymeOther laboratory investigation*prepared by xuejingwangOther laboratory investigationImmunological examination: ANCA, GBM Gene diagnosis: ADPKDSelection of renal functional tests*prepared by xuejingwangSelection of renal functional testsRoutine urinalysis( protein, glucose, RBC,WBC,pH etc.) Glomerular function tests: Ccr, Cr, Urea,UA,cystatin-C Tubular function tests: osmolality, urine protein analysis(quantitation and qualification) Tubular acidosis: blood-gas and acid-base analysis Early renal injury: combined analysis( albumin and transferrin + NAG and a1-microglobulin)