Basic laboratory tests in renal diseases

1
Basic laboratory tests in renal diseases

• Jana Granátová
• Dept. of clinical chemistry,
• Thomayer Hospital
• and 3rd Medical Faculty of Charles University
• ONLY FOR EDUCATIONAL PURPOSE FOR STUDENTS
• OF THE THIRD FACULTY OF MEDICINE !!!

2
Useful references

• The presentation
• Important numerical values
• Basic laboratory tests practical advices (a
  cookery book)
• https//sites.google.com/site/nphrologic/Home/cour
  se-8-edema-and-renal-disorders

3
When and whom to examine?

• asymptomatic population 17 with GFR lt 1,0 ml/s,
  renal disorder preexisting risk
• pre-operative (peri-, postoperative
  complications)
• potentially nephrotoxic therapy (aminoglycosides,
  contrast media, nonsteroid antiinflammatory
  drugs)
• age, diabetes, hyper/hypotension, combined
  therapy
• drug administration (doses cumulation)
• Diseases that can damage kidney - diabetes,
  hypertension, cardiovascular diseases
• long-term observation in renal diseases

4
Glomerular filtration rate (GFR)
5

• a basic test of renal function
• severity of damage
• - chronic - K/DOQI classification
  (Kidney Disease Outcome Quality Initiative)
• appropriate therapy, drug
  administration, indication to renal
• replacement therapy, predialysis
  care
• (mild, moderate, severe
  renal insufficiency descriptive - no
  definition,
• no clinical classification)
• - acute RIFLE criteria (s-creat., GF,
  urine output)

CKD stage GFR (ml/s/1,73m2)
1 normal GFR kidney damage (PU, HU) 1,5
2 mild renal insufficiency 1,0 1,49
3 moderate renal insufficiency 0,50 0,99
4 severe renal insufficiency 0,25 0,49
5 kidney failure, ESRD/RRT lt 0,25
6
Glomerular filtration rate

• ultrafiltrative pressure (blood flow in the
  kidney), filtrative area, number of nephrons
• approx. 2 ml/s/1,73m2 lower in female
• physiological decrease with age 0,17
  ml/s/1,73m2/10 years
• (80 90 y. 50 of function in 20 y.)
• decreases in kidney disease acute (AKI) and
  chronic
• chronic kidney disease (FSGS) decreased
  number of nephrons,
• compensatory residual hyperfiltration
• overload, nephron death,
  fibrosis.progressive worsening, fall in GF
• indirect indicator renal clearance (plasma
  volume cleaned off from substance XY in a time
  unit)

7

• Renal clearance
• GF clearance tubular secretion (or - tubular
  resorption)
• Clearance of inulin a golden standard, GF Cin,
  not for daily practice
• Radionuclid methods 99mTc-DTPA, 51Cr-EDTA,
• 
  125I-thalamate
• - more accurate (drop in plasma after i.v.
  administration)
• - both the kidneys separately (before kidney
  transplant.,
• stenosis of a. renalis)

8

• Clearance of endogenous creatinine, Ccr
• - daily 1-2 creatine (muscles, brain) ?
  creatinine (liver)
• - free filtred secreted in tubuli
• (physiologically 10 x in a chronic
  kidney failure gt 100,
• excreted through a gut)
• - as decreased GF, as overestimated Ccr
• - calculation based on u-creat., urine
  volume, time period (24 h),
• s-creat.
  
• - adjusted to body surface (weight, height)
  ml/s/1,73m2
• - reference values 1,5 2,0 ml/s/1,73m2
  (gender, age)
• females 8 -
  10 lower

9

• limitations
• - to collect urine correctly
• better in a hospital stay (x confused
  collecting vessels)
• (outpatient dpt. 40 pts. differ gt 30
  in collected
• volume more than 50 in
  calculated GFR value)
• - low muscle mass (low s-creatinine)
• - obese, fluid retention, swellings
  (creatinine distribution)
• - short time of collection (circadial
  rythms)
• - urine output lt 500 ml / 24 h
• - less realiable in late stages of CKD
  (overestimated GF)

10

• S-creatinine
• elevated
• - low excretion altered structure of
  kidney (glomerulonephritis,
• 
  interstitial nephritis, obstruction,
  malformation,)
• - functional altered renal perfusion
  (hypoxia, severe cardiac
• insuficiency,)
• - high production (polytrauma,
  acromegalia,)
• muscle mass, physique, diet, physical excercise,
  hydratation
• REMEMBER TO SEE YOUR PATIENT !!!
• limitations
• - muscle atrophy (age, immobilization,
  malnutrition)
• - swellings, hyperhydrated patient,
  (pregnancy)
• - rapid changes (biological half-time 24
  h!) critically ill patients
• (s-cystatin C,
  u-NGAL are better )
• Reference values
• male 62 115 µmol/l
  female 53 97 µmol/l

11

• non-linear dependence s-creat. and GFR
  (hyperbolic)
• a late indicator of kidney damage (GFR 50
  CKD-3)
• not to use for early diagnostics of decreased
  function
• (nephrotoxic therapy, early therapy)
• only 6/10 with slightly decreased
• GFR has increase in s-creat.

CYSTATIN C creatinine-blind
CREATININE
12
s-cystatin C

• produced by all nuclear cells at a constant rate
• serin proteases inhibitor
• free filtered in glomeruli completely resorbed
  metabolized
• in
  proximal tubuli
• its concentration in serum glomerular
  filtration
• estimated GFR (Grubb eGFR 1,412 x Scyst. -1,68
  x F)
• EARLIER INCREASE THAN S-CREATININE
• an early indicator of decreased GF
  (creatinine-blind , GF 50 99)
• independent on age, muscles, height and weight
• indication children, elderly, long-term
  immobilized, nephrotoxic therapy
• muscle atrophy, cachexia,
  pregnancy
• limitations
• - steroid therapy (worse GF)
• ? 25 50 , evaluate with
  s-creat., dependent on a dose
• - decompensed thyroid function (better
  in hypofunction)

13
Estimated GFR (eGFR)
THE ONLY S-CREAT. IS INACCURATE AND
LATE S-creat., age, gender, (black/other),
without an urine collection recommended together
with s-creatinine if it is standardized
(enzymatic) calculators
(www.kidney.org/professionals/tools/index.cfm)
value clinical conditions, patients
individuality 1,5 - normal,
higher values not given (underestimate -15-17)
1,0 1,49 - to evaluate individually (age,
clinical conditions) lt 1,0 -
pathological (LM in screen - if 0,67
ml/s/1,73m2 CKD 3 5
in gt 90 pts., AUC 0,97
for CKD 3- 5) not to use - rapid sudden
changes - pregnancy
- muscle atrophy (s-creat. lt 40
µmol/l) - young, healthy
14

• adults
• MDRD formula
• eGFR 515,3832 x (s-creat)-1,154 x
  age-0,203 x F1 (x F2)
• CKD-EPI formula
• female eGFR 144 x (S-creat. / 62-F) x
  0,993age , F S-creat lt / gt 62 µmol/l
• 
  
• male eGFR 141 x (S-creat. / 80-F) x
  0,993age F S-creat lt / gt 80 µmol/l
• Lund-Malmö formula
• eGFR eX - 0,1124 x age 0,339 x
  ln(age) 0,226 (if female)
• X 4,62 0,0112 x
  (s-creat), if lt 150 µmol/l
• X 8,17 0,0005
  x (s-creat) x ln(s-creat.), if gt150 µmol/l,
• (correct. To LBM
  (lean body mass)

15
Formulas are relatively comparatible
MDRD better for GF 0,5 1,0 ml/s/1,73m2
worse elderly gt 80 let
(18) CKD-EPI better for GFR 1,0 1,5
ml/s/1,73m2 (differs at 10 - 12 x 17)
for
general screen, elderly the both are
inaccurate - in young, healthy
individuals (CKD-EPI 22, MDRD 14)
- in males with low BMI lt 20 (CKD-EPI 36,
MDRD 46) - if GF lt 0,5
ml/s/1,73m2 - in children
LM better for GFR near to 1,5
ml/s/1,73m2
for GFR lt 0,5 ml/s/1,73m2
can be
used for children older 1 y.
16
children

• Schwartz s-creat., age, gender, height
• eGFR (F. height) s-creat.
• based on cystatin C (the same as in adults)
• Lund-Malmö (the same as in adults)
• maximal s-creatinine height (cm) x 0,54
• the highest normal s-creat . value
  fitted to normal GF (1,5 ml/s/1,73m2)
• (3 years approx. 100 cm 54 µmol/l x 2
  years 86cm 46,5 µmol/l f.e.)

17

• Záver do praxe 1
• Chci v praxi vedet, jakou funkci ledvin má muj
  pacient?
• Dospelý bežný pacient S-kreatinin (odhad GF)
• (eGF MDRD, event. CKD-EPI, Lund-Malmö)
• kreatinin ne ? S-cystatin C ( odhad GF z
  cystatinu)
• funkce štítné
  žlázy???, steroidy???
• svalová atrofie (kachexie, po imobilizaci,
  dystrofie, seniori) / muskulatura
• tehotná
• extrémne obézní
• pro dávkování léku
• Díte S-cystatin C (fyziognomie, svalová atrofie
  /dystrofie, vek)
• s-kreatinin ( eGF-Schwartz nebo
  Lund-Malmö,
• ne
  MDRD/CKD-EPI),
• orientacne maximální S-kreatinin

18
diagnosis and management of AKI

• Traditional diagnosis
• rise in s-creatinine
• (24 72h, fluctuating,
• 50 of function lost)
• fall in GF
• fall in urine output
• (!! non-oliguric AKI)
• - changes in a function

• NGAL
• real-time (30 120 min)
• changes in a structure

NGAL
From Vaidya, et al. Ann Rev Pharmacol Toxicol
2008
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NGAL (neutrophil gelatinase-asscociated
lipocalin)

• physiologically in neutrophile granules binds
  iron bacteriostatic effect
• produced early after the renal insult by
  epithelial cells in distal tubuli
• significan rise in 2 4 hours after nephrotoxic,
  ischemic insult
• functions
• - protective early, protects/reduces
  tubular epithelium damage
• - proliferative late, growth and
  differentiation of new tubular cells
• predicts the development of AKI on 2 days earlier
  than s-creat.
• (sepsis, major operations, cardiogenic
  shock, nephrotoxins,)
• proportional reponse to injury, no
  differentiation in causes
• measured in urine, results early (till 1 hour)
• indications ICU patients, major operations,
  cardiac surgery, contrast
• induced / cis-Pt
  nephropathy, graft recovery prediction

20
s-urea (blood nitrogen)

• protein metabolism (NH2) end-catabolite, in liver
• excreted 90 in kidney GF tubular resorption
  (30 40),
• (
  gut, skin in chronic kidney failure)
• increase not only if damaged kidney
• - high protein intake
• - catabolism (fever, sepsis, starvation,
  bleeding)
• - hydration (volume depletion)
• - congestive heart failure
• increases later than s-creatinine (if GF lt 30)
• faster and more in dehydrated and volume depleted
  patients
• diff. dg prerenal x renal causes of renal
  failure
• prerenal ? s-urea gt gt ? S-creat., ?
  u-urea, ? u-osmol.
• reference values 1,7 8,3 mmol/l

21

• Záver do praxe 2
• Podezrení na postižení ledvin bežný pacient,
  susp. chronické onemocnení
• S-kreatinin ( eGF MDRD, event. CKD-EPI,
  Lund-Malmö)
• S-urea, albumin v moci - ACR (je-li
  diabetik, hypertonik)
• Podezrení na akutní poškození ledvin (AKI)
• Ambulant trend s-kreatininu 3- 4 dny (event.
  cystatin C, viz výše)
• pokracující trend ?
  hospitalizovat
• cave
• biologická
  analytická variabilita s-kreat. mezi dny cca 15
• zmeny s-kreatininu se
  zpoždením 24 48h po inzultu
• Hospitalizovaný S-cystatin C, (event. NGAL)

22
Proteinuria (PU)
23
The kidney ? very efficiently ultrafiltrates
water, mineral and small molecules ?
efficiently restricts protein loss from plasma to
ultrafiltrate

(recirculation, resynthesis) blood flow rate
at 1,2 l / min ? daily 40 - 50 kg albumine
? 2
- 3 g/d into the ultrafiltrate
? only 30 mg/d
into a definitive urine glomerular wall
integrity, tubular resorption, physical-chemical
characteristics of proteins, microcirculation in
glomeruli
24
The glomerulus wall
Endothelium negatively charged Base membrane
3D sieve, loops diameter, negatively
charged Podocytes amount of water (and
protein) passing through a glomerulus wall
25

• Proteinuria
• transient functional in healthy kidneys
• - excessive physical excercise, severe
  stress
• - orthostatic in a standing, not in a
  lying position,
• till adolescence,
  asthenic physique,
• other laboratory
  tests normal, observe
• persistent repeately, always observe
• - kidney disease, even if normal GFR
• a sign of kidney / urinary tract disease
• an independent risk factor

26
Protein in urine urinary strips

• different limit of detection 0,15 - 0,30 g/l,
  low reliable
• concentration of proteins in urine,
  dehydration/polyuria
• false negative other proteins than
  albumine (tubular proteins
• interstitial nephritis, myeloma)
• false positive dehydrated, hematuria, pH
  gt 7-8,
• disinfectants,
  artificial (malingerers)
• A NEGATIVE RESULT DOESNT EXCLUDE PATOLOGICAL
  PROTEINURIA
• (normal total protein amount patological
  composition,
• 
  other proteins than albumin,
• proteinuria 15 g/mol creat. - in 1/3
  pathological composition)

27

• NOT FOR EARLY DIAGNOSTICS
• (early stages not detected, no
  intervention, no prophylaxis)
• not recommended for screen or follow-up
• (low reliability of changes in a
  semiquantitative scale)
• if positive 1 ? a quantitative test
• plus a test with 20 sulfosalicylic acid
  (the same reaction
• with all proteins in urine, confirmation
  of a negative result)
• Proteinuria risk factor renal (ESRD)
• and
  cardiovascular (mort., morbid.)

28
Proteinuria - quantity

• physiological
• previously 0,150 g/d (0,07 - 0,10
  g/l) - consensual
• now adjusted to u-creat. - PCR
  (protein-to-creatinine-ratio)
• 15 g/mol creat
• pathological
• mild lt 1
  g / 24 h
• moderate 1 - 3 g
  /24 h
• high gt 3
  g /24 h, PCR gt 100 g/mol
• nephrotic gt 3,5
  g/24 h
• nephrotic PU a risk of nephrotic syndrome (NS)
• NS nephrotic PU clinical and laboratory signs
  
• (swellings, low s-albumin, low s-total protein,
  dyslipidemia
• (?cholesterol, later triglycerides), accelerated
  atherosclerosis,
• thromboembolic complications (adults), infection
  (children)

29
Microalbuminuria

• mild elevated urinary albumin undetectable by
  ususal urinary strips (lt lt 150 mg/l)
• microalbuminuria strips limit of detection
  30 - 40 mg/l - for GP (positive)
• measure quantitative - ACR (mg/mmol creat.)
• ACR
  albumin-to-creatinine-ratio
• (not recommended
  in ug/min, mg/l, mg/d)
• a random urine sample, not collected urine
• physiological values lt 2,6 mg/mmol (male),
• lt 3,6
  mg/mmol (female) lower?
• microalbuminuria ACR 2,6 (3,6) 29,9 mg/mmol
  (30 mg/l)

30
MAU elevated cardiovascular and renal risk

• elevated risk also in high normal albuminuria
• (higher than 2 mg/mmol in male
  / 3 mg/mmol in female)!

Incidence of ESRD and albuminuria 10,3 r.
follow-up, HUNT-2 (Hallan et al, JASN 2009)
cardiovascular morbidity and mortality / 5
years, LIFE
31

• not to test
• - urinary tract infection,
• - after physical exercise
• - menses,
• - if positive protein in urinanalysis,
• - in acute diseases
• high variability in excretion (CVi 30) - to test
  repeately
• criteria positive in 2/3 tests in 3 - 6 months
• recommended to test regularly in
• - hypertension,
• - diabetes
• - cardiac ischemia

32

• Microalbuminuria in diabetes (DM)
• DMMAU a sign of incipient nephropathy (stage
  2-3 from 5)
• 10x higher risk of ESRD
• 4x cardiovascular complications
• 2x total mortality / 5 years
• DM-1 50 MAU ? 80 dia nephropathy (DN) with
  PU
• 50 without MAU ? vascular changes
• DM-2 40 - 50 MAU, manifest DN in fewer
  patients,
• more
  often nephrotic syndrome
• good metabolic control, corrected hypertension,
  ACEI
• to reduce / stop the progression to
  renal failure
• screen 1x in a year,
• - DM type 1 in 5 years after the
  diagnosis is given,
• - DM type 2 immediately

33
PU composition PU types

• indication
• - diff. dg. (f.e. PU 1 g/l cause GN / DM, HT
  / TIN?)
• - new PU (esp. in young, with a nephrotic sy,
  typical diagnosis and atypical findings)
• PU in DM 30 50 other than dia
  nephropathy
• - indication to renal biopsy (profit x risks)
• - replacement of renal biopsy if RB is not
  possible / at risk
• - how much altered progression - appropriate
  therapy
• (conventional x immune-supressive)
• - therapeutic response, compliance

34

• Proteinuria types
• according to its composition
• - glomerular
• - tubular
• - mixed (glomerulo-tubular)
• - prerenal
• - (postrenal)
• qualitative pattern
• (electrophoresis in urine)
• quantitative (some excreted proteins)
• albumin, IgG, a1microglobulin
• ratios, graphs, cut-off values

35
Physiological PU

• selective glomerular filter -
• (charge, large, Mr, shape)
• Mr lt 67 kD (albumin)
• tubular resorption (99)
• secretion
• 50 - 80 mg / 24 h
• consensually 150 mg / 24 h
• PCR 15 g/mol creat.
• uromodulin, THP 30 - 50 mg
• albumin 10 - 30 mg
• sIgA 10 - 15 mg
• polyclonal light chains
• 10 - 15 mg

Schneiderka P. Vybrané kapitoly z klinické
biochemie
36
Glomerular PU

• altered glomerular filter
• selective PU
• loss of a negative charge
• albumin, (transferin)
• minimal change nephritis,
• early stages of glom. diseases
• better prognosis
• nonselective PU
• more severe wall alteration
• large molecules are passed
• albumin, IgG
• index of selectivity IgG / Alb
• 0,03 - selective PU (MCN,
• response to steroids)
• gt 0,04 nonselective

37
Tubular PU

• altered tubular resorption
• mild PU (less than 1 g/d)
• microproteins (Mr lt albumin)
• a1microglobulin, ß2micro, RBP,
• strips often negative
• (sulfosalicylic acid positive)
• toxins (cisPt, aminoglycosides, heavy metals,
  X-ray contrast, toxins), ischemia, hypoK,
  hyperCa, hyperuricemia, acute obstruction,
  inflammation
• also a late consequence of glomerular PU (tubular
  atrophy fibrosis) - advanced changes

38
Mixed PU

• advanced disease (glomerular, systemic disease,
  severe chronic interstitial nephritis)
• tubular cells and glomeruli are altered by PU -
  toxicity of PU (glomerular sclerosis, atrophy of
  tubuli, sterile inflammation, nephrons are
  replaced by interstitial fibrosis)
• moderate / heavy, nonselective
• albumin, IgG a1microglobulin, and other
  proteins,
• as higher PU, as faster progression
• in DM, HT earlier than in GN

39
2 mild fibrosis and atrophy
1 normal tissue
3 moderate fibrosis and atrophy
4 severe fibrosis and atrophy
40
Prerenal PU

• healthy kidney initially
• ??? microproteins from blood
• (monoclonal light chains, hemoglobin,
  myoglobin)
• overestimated capacity of tubular resorption
• strips often negative
• (sulfosalicylic acid positive)
• myeloma, intravascular
• hemolysis, muscle contusion,
• catabolism, fever, inflammation,
• tissue necrosis
• leads later to altered tubuli

41
Postrenal PU

• proteins secreted in a lower urinary tract
• mild (less than 0,5 g/d)
• dominates leucocytes hematuria
• typical a2-macroglobulin, IgG
• inflammation, trauma, tumors

42

• Patient 1 25 y., male
• 1/2011 2 weeks ago tonsillitis (antibiotics)
  cold
• clinical fatigue, mild hypertension
• lab. S-creat. 140 168 µmol/l, border Ckr
  1,82 ml/s/1,73m2,
• urinanalysis active sediment (ery
  , leucocytes , casts)
• microHU, PU 2,8 g/l
• elevated C3C4, ASLO normal, negative
  autoantibodies (ENA, ANA,)
• suspected acute GN (post-infectious)?
• children 3 10 y, young, 10 gt 60 years
• infection in a history (bacterial, viral,
  toxopl., parazit.),
• may be asymptomatic - only with
  HU,
• ? ASLO (anti-DNase, anti-hyaluronidase),

43
PU typing PU 2,8 g/l, ???
albumin, ? IgG ? transferin, normal a1micro,
IgG/Alb. 0,07 Concl. glomerulonephritis with
glomerular nonselective PU,
without tubulo-interstitial damage, glomerular
HU renal biopsy IgA nephropathy with
crescents 30, active form IgA nephropathy
always hematuria - repeately macroHU
(respiratory, intestinal infecton) mild PU,
with/without renal insuficiency,
- proportional PU a HU, as higher PU, as worse
prognosis - asymptomatic microHU
(without PU / mild PU), - in all age,
children and young, more often males (6x)
- PU lt 1 g/l, if PU gt 1,5 g/l (10 - 15)
steroid therapy - correct diagnosis ? renal
biopsy - appropriate therapy acute GN non
specific, if steroids worse reparation
x IgAN mild form regime, active form /
heavy PU imune-supressive
44
Patient 2 26 y., male 2004 minimal change
nephritis, MCN (RB), nephrotic sy, imune-therapy,
repeated relapses (the last one month
ago) MCN fusion of podocate pedicels
regressive changes, normal
glomeruli normal GFR develops
fast nephrotic PU without microHU,
children 2 7 y., in adults rare, worse
prognosis (relapses) typical
glomerular selective PU selectivity effective
steroid therapy 1/2011 admission to
hospital worsening conditions relapse?
other? swellings of both lower
extremities, rise in PU s-creat. 86 µmol/l,
urea 10,6 mmol/l, low total protein (38 g/l),
very low albumin (16 g/l), high cholesterol
(9,4 mmol/l), high triglycerides (4,5 g/l),
very low IgG (lt 1,4 g/l), IgA IgM norm., PU
3,6 g/l (10,1 g/d) PU typing ????
albumin, ? IgG, norm. a1micro, IgG/Alb. 0,008
Concl. GN with glomerular high selective PU,
without altered interstitium,
without microHU another relaps effective
steroids in 5 days total protein
to 53 g/l, albumin to 35 g/l, PU drop to 0,13 g/l
45
Patient 3 52 y., female 2 weeks ago abdominal
pains, fatigue, anorexia, diarrhea, dyspnea,
S-krea 253 ... 410 µmol/l (in 4 days !),
elevated CRP (144129 g/l), inflammation and
acute obstruction excluded suspected rapid
progressive GN (RPGN) ? renal biopsy rapid
progressive GN (RPGN) HU PU rapid fall in
glomerul. function (gt 50 / 3 mths, crescents gt
50 - vasculitis (c-ANCA) Wegener
granulomatosis - immune-complexes
(post-infectious, collagenosis, other GN) -
anti-GBM-nephritis (without/with pulmonal damage
Good-Pasture sy) - can complicate any
GN weakness, fatigue, fever, anorexia,
abdominal pain, swelling of joints, (viral
infection in the history) if not treated,
in 3 months progression to ESRD
45
46
S-krea 871 532 242 µmol/l (10 days),
normal value in 4 months urea 24,928,917,3
mmol/l, elevated s-K (6,1 mmol/l), elevated s-P
elevated s-CK, very high myoglobin
(non-cardial), urinanalysis protein ,
blood , erythrocytes 5/ul, leucocytes 44/ul
CRP 84120,89,3 mg/l, elevated s-LD, high s-IgE
(486227) metabolic acidosis (pH 7,276, BE
-11mmol/l) blood count low Hb 8612083 g/l,
eosinophiles PU typing mild PU 0,16 g/l
??? a1-microglobulin, ? albumin Concl.
interstitial nephritis, interstitial mHU
renal biopsy acute interstitial nephritis
Concl. acute kidney failure - aTIN
hypersensitive rhabdomyolysis,
hemolytic anemia, iridocyclitis,
good response to steroids rhabdomyolysis
?s-CK myoglobin, urinanalysis blood , low
ery hemolysis ? Hb, ? s-LD,
hypersensitivity eosinofiles, high IgE AKF
(s-creat. urea) altered tubular functions ?
P ? K, metabolic acidosis diff. dg AKF (GN x
TIN), therapy, early diagnosis ? repaired
functions
46
47
Urinanalysis (chemical and morphological)
48

• results dependent on the quality of samples
• (middle stream of morning urine, hygiene, not
  if menses)
• analyze to 1hour (changes in pH, destroyed
  elements)
• diagnostic strips
• semiquantitative scale
• pH, specific gravity, protein, leucocytes,
  glucose, nitrites, blood/erythrocytes, ketones,
  bilirubin, urobilinogen

49
pH in urine

• usually 5 6,5
• possible 4,5 8,0 (strips, pH-meter)
• changes in pH - acidobase regulation
• alkalic pH (gt 7)
• - vegetarians,
• - alkalizing therapy (diuretics, secondary
  prophylaxis
• of
  urolithiasis, hyperuricemia),
• - vomiting
• - prolonged storage
• x - bacterial infection
• - compensatory in metabolic
  alkalosis
• - renal tubular acidosis
• (altered HCO3- resorption and
  acid urine production)

50
Blood in urine - strips

• positive erythrocytes / free hemoglobin /
  myoglobin (hem)
• erythrocytes - urinary tracts, kidney
  disease, bleeding
• hemoglobin - destroyed erythrocytes,
  intravascular
• hemolysis (?LD,
  total bilirubin, Coombs )
• myoglobin muscle contusion (?
  s-Mgb)
• false positive
• - menses, gynecologic (uterine cervix,
  vaginitis)
• - artificial (malingerers),
• - porphyria, dietary (red beet), drugs
  (rifampicine)

51
Why hematuria?

• Renal
• glomerular glomerulonephritis, systemic
  diseases, hereditary
• (sy of thin membranes,
  Alport. sy)
• tubulointerstitial acute nephritis, toxicity,
  acute obstruction
• vascular malignant hypertension, thrombosis /
  embolism
• other tumors (Grawitz / Wilms), cysts, necrosis
  of papila, trauma,
• nefrolithiasis
• Postrenal
• lithiasis, prostate, permanent urinary catheter,
  urothelial carcinoma, urinary tract infection
  (cystitis), trauma, tuberculosis, malformation,
• post-radiative, fistuli
• persistent macroHU in elderly in 20
  suspected urothelial ca
• Extrarenal
• anticoagulants, polycytemia, hematological
  malignancies, bleeding diathesis

52
Hematuria / Erythrocyturia
Hematuria (HU) blood in urine visible -
macroHU brown color
(Coca-cola) (in)visible microHU - strips /
urinary sediment (microscopy) Erythrocyturia
erythrocytes gt 30/µl non-glomerular -
interstitial (nephritis, Grawitz tu, cysts), -
lower urinary tracts (urolithiasis,
infection, trauma, urothelial/renal
carcinoma, prostate) usually only a mild
PU
glomerular - glomerulonephritis, -
other glomerular diseases, usually with PU if
HU PU usually GN
53
Erythrocyturia typing 1. Erythrocytes in phase
contrast glomerular 80
dysmorphic or 5 acanthocytes,
doughnuts-cells, erythrocyte
casts non-glomerular 80 eumorphic
limitation only in fresh urine, amount of cells
in sediment, subjective
evaluation, experience, grey zone
54
2. protein indexes (if proteinuria is present)
u-albumin/u-total protein proteinurie
glomerular 0,59
non-glomerular
lt 0,40 protein indexes (a2macroglobulin, IgG,
a1microglobulin und their ratios) only in some
laboratories - more specific
differentiation, objective
55
Patient 4 microHU renal glomerular
male, 61 y. his history 12/06 microHU, examined
by an urologist (excluded urolithiasis,
lower urinary tract infection and prostate
disease) first examined by a nephrologist
(1/07) exanthema, PU 2,6 g/l,
microHU, elevated IgA, urinanalysis protein ,
blood phase contrast 90 dysmorphic ery,
10 acanthocytes PU typing PU 2,8 g/l
??? albumin, IgG ?, mildly a1micro,
u-Alb/total protein 0,80
Concl. glomerular nonselective
PU, with mildly altered interstitium)
- glomerulonephritis, glomerular HU
? renal
biopsy focal segmental mesangioproliferative
IgAN with crescents
(RPGN), Henoch-Schönlein purpur ?
early biopsy early therapy, recovered renal
function
56
Urinary sediment
Basic morning urine, not older than 2h
(destroyed elements), carefully centrifuge,
differentiate elements - flow cytometry / camera
imaging SW analysis ( microscopy 400x)
erythrocytes 0 - 12 /µl
leucocytes 0 - 20 /µl sporadic
hyaline casts (more frequent diuretics,
excercise,
fever, low water intake) Collected
urine 3 h Hamburger sediment - quantified
elements
- disease
activity! erythrocytes 2000/min
leukocytes 4000/min casts
60 - 70/min
57
Leucocytes

• leucocyturia gt 15 / µl
• interstitial nephritis, cystitis, urethritis,
  prostatitis, carcinoma,
• surrounding organ diseases (gut, gynecological)
• leucocyturia without bacteriuria
• glomerulonephritis, systemic lupus, papila
  necrosis, cysts, nefrolithiasis,
• possible contaminated by vaginal fluid

58
Casts

• physiological hyaline - Tamm-Horsfall. protein
  (THP), sporadic
• pathological precipitates of THP content of
  distal tubuli and collecting ducts
• leukocytar interstitial nephritis, urinary tract
  infection, glomerulonephritis
• erytrocytar glomerular diseases (GN)
• granular glomerulonephritis, interstitial
  nephritis, acute tubular necrosis
• wax typical in diuresis-recovery stage just
  after oligo/anuria (obstruction),
• chronic renal failure
• fatty nephrotic sy
• Bacterial
• Epithelial tubular
• damaged tubuli

59
Urinary syndromes
nephritic dysmorphic erythrocytes, leucocytes,
casts GN, systemic lupus,
Henoch-Schönlein purpur, systemic vasculitis
(Wegener granulomatosis, Goodpasture sy,),
hemolytic-uremic sy nephrotic if nephrotic
proteinuria (gt 3,5 g / 24 h)
hyaline and fatty casts, possible cholesterol
crystals, dysmorphic
erythrocytes less frequently glomerular
diseases (MCN, FSGS, MGN, diabetic
nephropathy) minimal abnormalities isolated
microHU IgA nephropathy, residual after
acute GN, systemic lupus, Alport sy,
hypertension,
60
Concentration of urine
61

• urine is hypertonic (if compared to
  ultrafiltrate)
• - regulation antidiuretic hormone (ADH )
• stimulus s-osmolality changes
• ? S-osmol. (pure water loss unconsciousness,
  polyuria,
• 
  ? intake)
• ? ? ADH ? ? water resorption. ? urine
  output,
• concentrated urine (?u-osmol) .. drop in
  s-osmol.,
• hypertonic urine
• osmolality in urine gtgt in
  serum ( 600 mmol/kg)
• If not u-osmol. lt 600 diabetes insipidus
• - central (tumors, trauma
  hypophysis/hypothalamus)
• - peripheral (interstitial
  nephritis, toxins, hypoK)
• - mixed

62
?S-osmol. (polydipsia) ? very low ADH 0 ?
impermeabile for water, only NaCl resorbed ?
hypotonic urine, low u-osmol. osmolality in
urine lt in serum If not u-osmol. gt s-osmol
SIADH (sy of inadequate ADH secretion) (ADH
secretion stimuled if not ? S-osmol, ?U-osmol, ?
S-Na) water overdilution
(pneumonia, tuberculosis, brain trauma or
operation, tumors lung, pancreas, large
operation)
63

• How to test?
• (fluid restriction 24 36 h ? u-osmol.)
• in a daily practice u-osmol. in morning urine
  2x s-osmol.
• (approx. 600 mmol/kg), in young 900
  mmol/kg (3x)
• if not isostenuria u-osmol.
  s-osmol.
• (advanced chronic renal
  insuficiency)
• - adiuretin test (DDVAP ADH analogue)
• (DDVAP i.nas. administration in the
  morning, measured u-osmol. in 4 h)
• u-osmol. 1100 800 mmol/kg H2O - age)

64
osmolality
Refer. values serum 275 295 mmol/kg H2O
urine 400 900 (50
1200) mmol/kg H2O
(u-osmol. lower in breast-feeding and
elderly) in a daily practice calculated
osmolality serum 2 x s-Na glucose
urea osmolal gap big
difference measured vers. calculated value
normal 5 - 10 mmol/kg
H2O elevated
toxins (1 alcohol 23 mmol/kg H2O),

catabolism, hyperglycemia urine 2 x
(u-Na) (u-K) (u-urea) NH4

(NH4 approx. 30 50 mmol/d)
65
Minerals
66
Sodium (Na)

• main extracellular cation osmotic pressure
• to evaluate together with water Na
  retention water retention,
• 
  Na overload water overload
• regulation
• A) depleted EC fluids
• - loss of isotonic fluids (vomiting,
  bleeding, ascites, ileus)
• risk of collapsed
  circulation - blood pressure (BP) falls
• ? renin (juxtaglomerular)
  angiotensinogen (liver) angiotensin-II
• ? vasoconstriction rise in blood
  pressure
• ? aldosterone (adrenal cortex)
• Na and water reabsorbed in
  distal tubulus rise in BP
• u-Na lt u-K, u-Na lt 20
  mmol/l (lt 10 mmol/l)
• - loss of pure water - low ADH, ? S-osmol.
  changes between EC
• and IC space, collapsed
  circulation observed until severe
• dehydratation

67
B) excess Na and water, expanded EC fluids
natriuretic peptides regulates
extracelular volume and blood pressure
ANP, BNP, CNP left ventriculus and atrium,
endotelium, brain, lung,
kidney, aorta, suprarenal glands
stimulus ? volume / filling pressure
atrial / ventricular to protect
pressure and volume overload - endogenous
diuretics
- ? urine output, u-Na excretion,
- against
renin-angiotensin-aldosterone -
vasodilatation (sympathetic antagonists)
overloaded circulation (heart failure, left
ventricular hypertrophy, renal
failure with oliguria,
hyperaldosteronismus) Reference values
serum 135 146 mmol/l
urine 50 220 mmol/l
FENa 0,010 0,012
68
Potassium (K)

• main intracellular cation (EC IC 4,5 140),
  irritability
• to evaluate together with acidobase - H
  (acidosis - ?K, alcalosis - ?K)
• pH ? 0,1 0,3 - 0,4 mmol/l K
• regulation
• - resorbed in proximal tubulus,
• - secreted in distal tubulus (K,
  H/Na)
• aldosteron
  (stimulates K excretion)
• elevated in urine renal failure, loop
  diuretics, catabolism,
• 
  hyperaldosteronism
• !! hyperaldosteronism
  unclear hypoK, ? u- K, u- K gt u-Na
• decreased in urine extrarenal loss -
  gastrointestinal (K 3x more vers
• plasma),
  low intake, anabolism
• Reference values serum 3,8 5,4 mmol/l
• urine 45
  100 mmol/d
• FEK
  0,04 0,19

69
Excrete fractions

• ratio of compound XY filtred by glomeruli and
  excreted in definite urine
• show tubular functions FEx Ux x Pkr / Px x
  Ukr
• FE H2O 0,01 0,02 (max. 0,035)
• FENa 0,004 0,012 (max. 0,30 0,40)
• FEK 0,04 0,19 (max. 1,5 2,0)
• FEosmol. lt 0,035 (max. 0,035)
• without long urine collection
• diff. dg. prerenal x renal failure
• prerenal low FENa lt 0,01, ( low
  u-Na lt 20 mmol/l)
• (intra)renal high FENa gt 0,03, ( u-Na
  gt 30 mmol/l)