诊断学：常用肾脏功能实验室检测

诊

断

学

肾功能检查

ASSESSMENTOFRENALFUNCTION

提要UrineTests:Cheapandconvenient;ForscreeningandfollowingRenalFunctionsImmunologicalTestImagingExaminationRenalBiopsy3WhenorforWhatKidneydiseasesorinjuriesOtherdiseasesinducedkidneyfunctioninjuriesDiabetesmellitusHypertensionShockorextensiveburnAuto-immunologicaldiseasesDrugtoxicity4StructureofKidney5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Glomerularfunctionassessment6StructureandFunctionGFR:thevolumeoffluidfilteredfromtheglomerularcapillariesintotheBowman'scapsuleperunittime120-160ml/minContentsSerumCreatinine(sCr)&Serumurea(SU)CreatinineClearanceRate,CcrCystatinCMicroalbumin(MA)、Transferrinuria(TRU)、uricacid、urineIg……SerumCreatinine(sCr)Endogenous

awasteproductproducedbymusclemetabolismCreatinineExogenous

Comefromfoods,suchasmeat,fish,coffee,tea,etc.9SerumCreatinine(sCr)Asmallmolecule,filtratedbyglomerularcompletely,andnotreabsorbedbytubulesCr:riseifthefilteringofthekidneyisdeficient,NormalValue:SerumCr:male:44-132μmol/Lfemale:70-106μmol/L10Stageofrenalfailure(male)11>445μmol/L>178μmol/L<177μmol/L44-132μmol/LStage4(Failurestage)Stage3(De-compensatorystage)Stage2(Compensatorystage)Stage1(Normalfunction)>707μmol/LStage5(Uremia)ScrClinicalSignificanceofsCrincrease12riseonlywithmarkeddamagetonephronsfiltrationSerumurea(SU)alsonamedasBUNInfluencefactorsProteinintakeProteindegradationLiverfunctionGlomerularfiltrationNormalvalue:Adults:1.8-7.1mmol/LChildrenorinfants:1.8-6.5mmol/L13UreaorornithinecycleinliverClinicalSignificanceofSURenaldamage:ChronicrenalfailureCompensatorystage:SU<9mmol/LDecompensatorystage:SU>9mmol/LFailurestage:SU>20mmol/LUremia:SU>28.6mmol/LAcuterenaldisease14ClinicalSignificancePhysical:↑：highproteindiet↓：pregnancyPre-renal:Highfever,Shock,Uppergastrointestinalhemorrhage,extensiveburn，severetrauma……Post-renal:Obstructioninurinarytract15SU/Crratio:BUN:7-20mg/dLUrea:2.5-10.7mmol/LsCr:0.7-1.2mg/dLsCr:70-106μmol/LBUN:CrUrea:CrLocation>20:1>100:1Pre-renal10-20:140-100:1NormalorPost-renal<10:1<40:1Intra-renalCreatinineClearanceRate,CcrDefinition：Ccristhevolumeofbloodplasmawithcreatininethatisclearedbykidneysperunittime.即：单位时间内,肾脏可全部清除多少毫升血浆中的肌酐Normalvalue：80-120ml/min·1.73m2ClinicalSignificanceofCcrPhysiological：relatedwithsports,diets,age……PathologicaldecreaseSensitiveforkidneyinjuryGFR<50%时Ccr≈50ml/minStageofrenalfailure1910-20ml/min20-50ml/min>50ml/min>80ml/minStage4(Failurestage)Stage3(De-compensatorystage)Stage2(Compensatorystage)Stage1(Normalfunction)<10ml/minStage5(Uremia)CCrFortreatmentStageIIobservation,controlofbloodpressure.StageIIIa(30-40ml/min)

limitedproteindiets,treatmentofcomplication,diureticStageIIIb

(<30ml/min)diureticisnotavailable20StageIVcombinetreatment,planningforend-stagefailure

StageVreplacementtherapy,transplantationordialysis

StageofkidneyimpairementCcr

（ml/min)sCr(umol/L)SU(mmol/L)Compensatorystage

80-50<177<9Decompensatorystage

50-20178-1449-20Renalfailure20-10445-70720-28.6end-stagerenalfailure(uremia)<10>707>28.6Expressedinallnucleatedcells,encodedbyhousekeepinggeneLowmolecularweight,FiltratedfreelythroughglomerulusConcentrationinserumorplasmaisdeterminedbyGFRCystatinCCystatinCbetterthancreatinineinpredictingCystatinCbetterthancreatinineinpredicting优点Highsensitivity：betterthanCcrHighspecificity：notinfluencedbyacutephasereaction,activities,genderandage,etal.Usedwidely:forrenaltransplantationstatusformonitoringGFRinnephrotoxicdrugtherapyforacuteandchronickidneydiseasesincludingadiabeticnephropathyOperatedeasily肾小管功能检查Testsoftubularfunction26Functionofrenaltubular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Testsofproximaltubularfunction28TestsofProximaltubularFunctionβ2-microglobulinα1-microglobulinRetinol-bindingprotein,RBPN-acetyl-β-D-glucosaminidase,

N-NAGFractionofurinenatriumexcretion,FeNaβ2-microglobulin,β2-MGPresentonallnucleatedcells,especiallyonlymphocytes,andstableinbloodSmallprotein,freelyfiltratedbyglomeruliAlmostreabsorbedbytubulescompletelyThresholdofreabsorption:5mg/LNormalvalue:Urine：<0.3mg/LClinicalSignificanceofβ2-MGSerumβ2-MG↑：GFR↓:whenCcr<80ml/min，moresensitivethanScr恶性肿瘤、炎性疾病（肝炎、类风湿关节炎等）Reabsorptionfunctionofproximaltubules：urineβ2-MGincrease(bloodβ2-MG<5mg/L)AcuteandchronicpyelonephritisDrugortoxininducedtubularnecrosisClinicalSignificanceEvaluationfortransplantkidneyfunctionUrineβ2-MG↑↑，impliedgraftrejectionserumβ2-MG:helpforsub-clinicalrejectionofgrafts肾移植虽有少尿，但血β2-MG下降者提示预后良好。α1-microglobulin,α1-MGSmallglycoproteins,synthesizedinliverFreelyfiltratedthroughglomeruliAlmostreabsorbedbyproximaltubulescompletelyNormalvalue:Urine：<15mg/24hClinicalSignificanceofα1-MGDecrease:severehepatitisandhepaticnecrosisSerumα1-MG

↑：GFR↓:whenCcr<100ml/min，moresensitivethanScrandβ2-MGUrineα1-MG↑:Reabsorptionfunctionofproximaltubules

injuryAcuteandchronicDiabeticnephropathyα1-MG↑：serumandurineDamageinbothglomeruliandtubulesRetinal-bindingprotein,RBP视黄醇结合蛋白Canbedetectedwidely,inallbodyfluidFreelyfiltratedbyglomeruli,almostreabsorbedbytubulescompletely,anddegeneratedintoaminoacidsOnlyalittlewasexcretedwithurineNormal:0.11±0.07mg/LClinicalSignificanceBloodRBP:Increase:glomerularfunction

HigherspecificityandsensitivitythanScrDecrease:liverfunction,malnutritionUrineRBP:tubularfunctionmorespecific:similarsensitivewithβ2-MGandsensitivethanScrbetterstabilityN-acetyl-β-D-glucosaminidase(NAG)N-乙酰-β-D-氨基葡萄糖苷酶widelydistributedlysosomalhydrolasenotfilteredattheglomerulusLocatedpredominantlyintherenalproximaltubulesExcretedinlowamountsinurineClinicalSignificanceUrineNAGincrease:exocytosisprocessoftubularcellsToxicacutetubularinjuries:lead,aminoglycosideantibiotics,nephrotoxicdrugs,anti-cancerdrugs(cisplatin……)Acuterejection:Variousglomerulardiseases:diabeticnephropathy,hypertensivenephropathyUrinaryinfection:upper>lower，locationFractionofurinenatriumexcretionNatrium:freelyfiltratedthroughglomeruliand99%wasreabsorbedbyproximaltubulesNormalvalues:FeNa:<1%ClinicalSignificancePre-renal：钠摄入过多或血容量下降尿钠↑同时伴有血钠↑Reabsorptiondamage:急性肾小管坏死尿钠↑，但血钠不高DifferentialdiagnosisofazotemiaPrerenal:

FeNa<1%Renal:（肾小管性）

FeNa>1%Summaryβ2-microglobulinα1-microglobulinRetinol-bindingprotein,RBP——reabsorptionfunctionN-acetyl-β-D-glucosaminidase,

N-NAG——kidneytoxicitydamageFractionofurinenatriumexcretion,FeNa——differentialdiagnosisofpre-renalandintra-renalazotemia远端肾小管功能检查Testsofdistaltubularfunction42RenalconcentrationfunctionMosenthal’stestAlsoas:Circadianurinespecificgravity(SG)testNormalintake(water<500-600ml),noextrawaterEmptybladderat8aminthemorningDetectthevolumeandSGo