DDX Kidney lecture

Question 1

Pain - LITRAAA

Answer 1

localization, intensity, type, radiation, aggravating – alleviating factors, accompanying signs

Question 2

Pain - Sudden onset, cramping

Answer 2

Obstruction of the urinary tract

Question 3

Pain - Blunt, unilateral

Answer 3

renal cyst infection/bleeding,
tumor,
renal infarct,
renal vein thrombosis,

with fever and UTI:
pyelonephritis,
abscess

Question 4

Pain - Blunt, bilateral

Answer 4

interstitial nephritis,
renal edema,
glomerular diseases are usually not painful

Question 5

Pain - Dysuria, pollakisuria

Answer 5

Lower UTI

Question 6

Hematuria - Macroscopic

Answer 6

suggest urological origin (but may be seen in IgA nephropathy)

Question 7

Hematuria - Microscopic

Answer 7

may be either urological or nephrological in origin

Question 8

Hematuria - Urology causes

Answer 8

Renal/uroepithelial tumor, 
stone, 
UTI (eg. cystitis), 
renal cyst rupture, 
papillary necrosis

Question 9

Hematuria - Nephrological causes

Answer 9

Glomerulonephritis,
Alport-syndrome,
thin basement membrane disease,
acute interstitial nephritis

Question 10

Hematuria - Healthy person

Answer 10

Dipstick negative, sediment < 3-4 RBC/high power field

Question 11

Hematuria - isomorphic RBCs

Answer 11

Urolological

Question 12

Hematuria - dysmorphic RBCs

Answer 12

Nephrological

Question 13

Proteinuria and albuminuria - „clinically significant” proteinuria:

Answer 13

> 500mg/day (>50mg/mmol creatinine)

Dipstick usually positive for proteins

Question 14

Proteinuria and albuminuria - microalbuminuria

Answer 14

> 30mg/day (30 mg/mmol)

May suggest early diabetic nephropathy

Is associated with cardiovascular events

Question 15

Proteinuria - „nephrotic” proteinuria

Answer 15

> 3-3.5g/day (0.3-0.35 g/mmol) that is accompanied with the nephrotic syndrome

Question 16

Proteinuria - Spurious proteinuria (non renal)

Answer 16

inaccurate sampling,
blood in the urine,
colpitis

Question 17

Proteinuria - Functional

Answer 17

temporary:
fever,
intense physical exercise,
venous congestion

Orthostatic proteinuria

Question 18

Proteinuria - Glomerular: glomerulonephritis, glomerulopathy

Answer 18

Damaged glomerular tuft spills albumin and variable amount of globulins in the primary filtrate

(more severe damage more globulin)

Question 19

Proteinuria - Tubular proteinuria

Answer 19

Damage to the proximal tubule leads to failure to reabsorb small molecular weight proteins

(eg. Fanconi syndrome, interstitial nephritis)

Question 20

Proteinuria - „overflow” proteinuria

Answer 20

High amount of small molecular weight protein in the serum is being filtered and overflows reabsorption

(kappa/lambda light chains a.k.a. Bence-Jones proteinuria)

Question 21

Urinary electrophoresis - Albumin spike

Answer 21

AL amyloidosis

Question 22

Urinary electrophoresis - Gamma spike

Answer 22

Multiple myeloma (often w/ albumin spike)

Question 23

Urinary electrophoresis - General increase

Answer 23

Nephrotic syndrome

Question 24

Immunological tests - ANA (anti-nuclear antibody)

Answer 24

SLE, other systemic autoimmune disease

Question 25

Immunological tests - ANCA (anti-neutrophil cytoplasmic antibody)

Answer 25

Small vessel vasculitis (pauci-immune crescentic GN)

Question 26

Immunological tests - Anti-dsDNS antibody

Answer 26

SLE

Question 27

Immunological tests - SS-A, SS-B antibody

Answer 27

Sjögrens’ syndrome, SLE

Question 28

Immunological tests - Anti-GBM antibody

Answer 28

Goodpasture syndrome

Question 29

Immunological tests - Anti-streptolysin antibody

Answer 29

Poststreptococcal glomerulonephritis

Question 30

„Major” nephrology syndromes

Answer 30

* Nephritis * Rapidly progressive glomerulonephritis (RPGN) * Nephrosis * Acute kidney injury * Asymptomatic proteinuria and/or haematuria * Chronic kidney disease

Question 31

Nephritic syndrome hallmarks

Answer 31

* Hematuria * Proteinuria * Urinary casts (RBC) * Hypertension * Edema * Oliguria * Decreased GFR

Question 32

Differential diagnosis hallmarks: Postinfectiosus glomerulonephritis

Answer 32

subacute endocarditis, abscess

Question 33

Differential diagnosis hallmarks: Membranoproliferative glomerulonephritis

Answer 33

Lupus nephritis, cryoglobulinemia, monoclonal immunoglobulin deposition „dens-deposit” disease, C3 glomerulonephritis

Question 34

Rapidly progressive glomerulonephritis syndrome (RPGN) - general overview

Answer 34

Rapid worsening of kidney function (weeks/months) Nephritic urinary findings • Glomerular hematuria, variable proteinuria • Cellular (RBC) casts ``` Frequent systemic symptoms • vasculitis • Pulmonary (bleeding) • upper airway infection (usually occurs DURING an ongoing mucosal infection) • Arthritis • Fever • Neuropathy ```

Question 35

RPGN Light microscope

Answer 35

Crescents with parietal cell proliferation | Glomerular necrosis

Question 36

Differentiation of crescent glomerulonephritis with RPGN: 1. Linear immunglobulin deposition

Answer 36

* Anti-GBM antibodies * Renal +/- pulmonary symptoms * Goodpasture disease

Question 37

Differentiation of crescent glomerulonephritis with RPGN: 2. Granular immunglobulin deposition

Answer 37

* These are immuncomplexes | * eg. lupus nephritis, IgA nephropathy

Question 38

Differentiation of crescent glomerulonephritis with RPGN: 3. No immunglogulin deposition

Answer 38

``` „pauci-immune” = „hardly any” • These are ANCA vasculitides • Granulomatosis with polyangitis • Microscopic polyangitis • Eosinophil granulomatosis with polyangitis ```

Question 39

Nephrotic syndrome overview

Answer 39

* Proteinuria (usually >3 g/day) * Hypolbuminemia * Edema * Hyperlipoproteinemia * Thromboembolic events * GFR may be normal

Question 40

Differential diagnosis of the nephrotic syndrome: Primary renal disease (no other organ involvement)

Answer 40

– Primary membranous glomerulopathy (usually anti-PLA2 receptor antibody positive) – Minimal change nephropathy – Primary focal segmental glomerulosclerosis

Question 41

Differential diagnosis of the nephrotic syndrome: Renal manifestation of a systemic disease

Answer 41

– Diabetic nephropathy – Amyloidosis – Secondary FSGS (congenital podocytopathy, HIV, extreme obesity, glomerular loss for an unrelated reason) – Secondary membranous glomerulopathy (lupus nephritis, malignancy, drugs, hepatitis B/C, syphilis, NSAIDs, TNF- inhibitors)

Question 42

Indications for renal biopsy

Answer 42

* Nephrotic syndrome * Nephritic syndrome * RPGN * Asymptomatic proteinuria in the 1-3g/day range (particulary if GFR declines or proteinuria increases) * Acute kidney injury (intrinsic) * If there is a suspicion that it is not caused by acute tubular necrosis * Chronic kidney disease of unknown origin * But not if on US small scarred kidneys * Dysfunction of transplanted kidney

Question 43

Contraindications to renal biopsy

Answer 43

* Uncooperative patient * Single kidney * Multiple renal cysts * Renal neoplasm * Acute pyelonephritis * Uncontrolled bleeding diathesis * Uncontrolled blood pressure (BP > 160/95 mmHg)

Question 44

Asymptomatic urinary abnormality - Asymptomatic proteinuria (usually 0,5-2g/day)

Answer 44

Glomerular diseases eg. * Early diabetic nephropathy * secondary FSGS * Hypertensive nephropathy

Question 45

Asymptomatic urinary abnormality - Asymptomatic microhaematuria

Answer 45

Glomerular diseases eg. * IgA nephropathy * Alport syndrome * Thin basement membrane abnormality