CKD Flashcards
What is erythropoeitin?
It is a glycoprotein hormone secreted from the peritubular endothelial cells and interstitial fibroblasts.
It acts on the bone marrow to produce RBC and WBC.
Mechanism of EPO
- Binds to erythropoeitin receptor
- Then JAK2 kinase is activated
- This activates other pathways such as STAT, PIK AND MAPK
- This leads to differentiation, proliferation and survival of red blood cells
Erythropoeitin stimulating agents (ESAs)
Also known as recombinant human EPO
There are two types: alpha and beta
Uses are:
- Anemia in CKD
- Anemia in MDS
- Anemia in cancer patients
- Used by athletes
Side effects of EPO
- Myocardial infarction
- Stroke
- Venous thromboembolism (VTE)
- Tumour recurrence
Acute renal failure
- Damage to kidneys lowering GFR
- Reversible
Prerenal
- Sudden or severe decrease in blood pressure
- Flow obstruction to kidney via ischemia or athersclerosis
Intrarenal
- Direct damage to kidney
- Inflammation of kidney
- Infection
- Drug
- Autoimmune disease
Most common form of acute renal failure
Post renal
Obstruction of urine flow
- Benign prostatic hyperplasia, kidney stones, bladder injury, tumour
Risk factors of AKI
- Age over 65
- CKD
- Cardiac failure
- Hypovolemia
- Diabetes mellitus
- Nephrotoxic drugs (NSAIDs, ARBs, ACE inhibitors and cyclosporin)
Erythrocyte
Life span of erythrocyte is 100-200 days.
Old RBC become rigid and hemoglobin degenerates. When RBC is engulfed by macrophage the heme and globin separate. Iron is removed from heme and salvaged for reuse - stored as hemociderin or ferritin in tissues.
Erythrocytes contain spectrin which provide flexibility.
Causes of hypoxia
- Haemorrhage or increased destruction of RBC
- Abnormality of hemoglobin - iron deficiency
- Reduced oxygen
What is anemia?
Functional inability of the blood to supply tissues with adequate oxygen for metabolic functions due to:
- Erythrocyte loss
- Decreased erythrocyte production
- Increased erythrocyte destruction
Types of anemia
- Iron deficiency
- Vitamin B12 or folic acid deficiency - DNA synthesis impaired and no cell division just cell growth
- Aplastic anemia - Stem cells in bone marrow damaged and affect all blood cells
- Abnormal haemoglobin
- Haemolytic anemia - Breakdown of RBC in blood vessels/spleen
- Renal anemia - Low renal blood flow, low EPO
What is CKD?
Decrease in kidney function/ structural damage or both for greater than 3 months
GFR
Normal GFR rate is 100-120ml/min/1.73m2 and slightly less in women