Refers to red blood cells clumped together in urinalysis and are from the glomeruli of the kidney.
Red cell casts appear as clear cylinders containing red blood cells and may have an orange-red tinge.
Red blood cells normally are prevented from passing through the normal glomeruli and when damage is present they pass into the tubules of the kidney.
Their presence indicates bleeding into the nephron.
Red cells within the cast are rapidly hemolyzed.
The cast becomes a hemoglobin cast, having an orange color and a homogeneous ground-glass texture.
The presence of red blood cells within the cast is always pathological and is strongly indicative of granulomatosis with polyangiitis, systemic lupus erythematosus, post-streptococcal glomerulonephritis, or Goodpasture’s syndrome.
Red blood cell casts can also be associated with renal infarction and subacute bacterial endocarditis.
Red blood cell casts are a yellowish-brown color and are generally cylindrical with sometimes ragged edges.
They are usually associated with nephritic syndromes or urinary tract injury.