Kidneys and EPO

Function of HIF-1

Bind to hypoxia response element in EPO gene → Causes EPO synthesis

What conditions drive erythropoiesis

Decrease oxygenation → Low blood volume, anemia, low Hb, poor perfusion, pulmonary disease

How is iron metabolized in the body

Absorbed in small intestine → Convert into transferrin in plasma → Goes to RBC Hb or is free in tissue

How is free iron formed by RBC

When RBC is old → MC degrade the cell → Product is free iron

What defines CKD

Abnormalities present for minimum 3 months based on markers and GFR

What are the markers for kidney damage

Albuminuria, hematuria, history of kidney transplant abnormalities of: urine sediment, electrolyte, histology, structural (by imaging)

What is the normal GFR value and what is the cut off for CKD

Normal is >= 90 ml/min; cutoff for CKD is <60 ml/min

What are the common causes of CKD

Diabetic, nephropathy, hypertensive nephrosclerosis, glomerulonephritis, obstructive uropathy, polycystic kidney disease, Gout

In Thailand, are the most common causes of CKD

Diabetic nephropathy and hypertensive nephropathy

How is UACR calculated

(Urine albumin in mg/dL / Urine creatinine mg/dL) * 1000 = mg/g Cr

Can CKD be diagnosed with only GFR

NO; albuminuria is needed for diagnosis; albuminuria also predicts mortality

Why is anemia common in CKD

90% of EPO is made in kidney → CKD has kidney damage → No EPO

Prevalence of anemia is found in what groups

Higher stage of CKD, older age, non-smokers

Why do smokers have lower incidence of anemia than non smokers

Smoking causes tissue hypoxia → Induces EPO to synthesize RBC

What are EPO stimulating agents (ESA)

Treatment of choice for anemic patients with CKD

What is the algorithm for management of anemia

Hb <12 in women or <13 in men → Find cause of anemia → If not found do iron study → Low iron give iron → If iron normal do ESA

What is pure red cell aplasia

Condition caused by production of anti-EPO Ab; RBC is low but WBC and PLT are normal → Treat by stopping ESA

What are HIF stabilizers

Competitively inhibit HIF enzymes → Prevents HIF degradation → Effect is increased EPO