TY  - CHAP
M1  - Book, Section
TI  - Approaches and Chief Complaints in Nephrology
A1  - Huppert, Laura A.
A1  - Dyster, Timothy G.
PY  - 2021
T2  - Huppert’s Notes: Pathophysiology and Clinical Pearls for Internal Medicine
AB  - Definition:-  Urine  protein  to  creatinine  ratio  (UPCR)  >150  mg/g  or  24-hr  protein  >150  mgGreater  than  3  g/24  hr  is  nephrotic-range  proteinuria-  Urine  albumin  to  creatinine  ratio  (UACR)  >30  mg/g  or  24-hr  albumin  excretion  >30  mg30–300  mg/g  is  termed  microalbuminuria>300  mg/g  is  termed  macroalbuminuriaEtiology:-  Glomerular  proteinuria:  Increased  glomerular  permeability;  due  to  primary  glomerulonephritis  (GN)  or  GN  secondary  to  systemic  illness  (e.g.,  diabetes)-  Tubular  proteinuria:  Impaired  tubular  reabsorption  due  to  tubular  dysfunction;  seen  in  tubular  interstitial  injury  from  systemic  illness,  congenital  disease,  endogenous  toxins  or  exogenous  toxins  (e.g.,  beta-lactam  antibiotics)-  Overflow  proteinuria:  Impaired  resorptive  ability  of  the  proximal  tubule;  due  to  excess  filtration  and/or  production  of  proteins  (e.g.,  hemolysis,  rhabdomyolysis,  Bence-Jones  protein  in  multiple  myeloma,  amyloidosis)-  Other:  Fever,  exercise,  orthostatic  proteinuria  (i.e.,  proteinuria  only  when  standing;  benign/self-limited,  typically  occurs  in  young  people)Diagnosis:-  Spot  tests:  UPCR,  UACR,  or  dipstick;  dipstick  detects  albumin  ranges  from  1+  (30–100  mg/dL)  to  4+  (>1000  mg/dL)-  24-hour  urine  is  rarely  needed,  but  may  be  useful  in  establishing  the  accuracy  of  spot  tests  and  quantifying  a  baseline  level  of  proteinuria  in  a  patient  with  persistent  proteinuria;  however,  it  is  cumbersome  and  susceptible  to  collection  errorPearls:-  Multiple  myeloma  and  other  light-chain  diseases  will  produce  proteinuria  without  significant  albuminuria;  therefore,  UACR  or  dipstick  will  be  “falsely”  negative  (or  unexpectedly  mild)-  Dilution  and  high  pH  may  also  yield  false-negative  dipstick  results.  Specific  gravity  should  be  greater  than  >1.005  and  pH  <8  for  accurate  results.-  Persistent  proteinuria  is  associated  with  progression  of  kidney  disease,  and  thus  is  often  a  treatment  target  and  a  surrogate  outcome  in  the  treatment  of  kidney  disease.  One  needs  to  identify  the  underlying  cause  and  treat.  ACEi/ARBs  are  often  used  to  improve  proteinuria.  
SN  - 
PB  - McGraw Hill
CY  - New York, NY
Y2  - 2024/04/24
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1189913242
ER  -