Most common cause of precipitation of renal failure in multiple myeloma is
(C) Hypercalcaemia # Renal failure is seen in 25% patients and hypercalcaemia is the most common cause of renal failure.> Quite often renal failure develops rapidly even at an unchanged ratio of production and serum concentration of light chains. Various factors can favour renal cast formation in myeloma patients. Dehydration, sometimes due to diuretics, reduces the glomerular filtaration rate (GFR) and causes an increase in the plasma concentration of light chains which then exceeds the capacity for reabsorption and catabolism of light chains in the proximal tubuli.> Hypercalcaemia may induce vasoconstriction followed by a decrease in GFR. Several drugs, in particular non- steroidal anti-inflammatory agents (NSAIDs), reduce renal blood flow. Radiographic contrast agents may induce acute renal failure in myeloma patients, particularly if patients are dehydrated and ionic contrast media are used.> The osteoclasts respond to osteoclast activating factors (OAF) made by the myeloma cells . leading to hypercaicaemia. Renal failure occurs in nearly 25% of myeloma patients, and some renal pathology is noted in over half. Hypercalcemia is the most common cause of renal failure. Glomerular deposits of amyloid, hyperuricemia, recurrent infections, and occasional infiltration of the kidney by myeloma cells all may contribute to renal dysfunction. However, tubular damage associated with the excretion of light chains is almost always present. Normally, light chains are filtered, reabsorbed in the tubules, and catabolized. With the increase in the amount of light chains presented to the tubule, the tubular cells become overloaded with these proteins, and tubular damage results either directly from light chain toxic effects or indirectly from the release of intracellular lysosomal enzymes. The earliest manifestation of this tubular damage is the adult Fanconi syndrome (a type 2 proximal renal tubular acidosis), with loss of glucose and amino acids, as well as defects in the ability of the kidney to acidify and concentrate the urine. The proteinuria is not accompanied by hypertension, and the protein is nearly all light chains. Generally, very little albumin is in the urine because glomerular function is usually normal.
Hyperurecemia
Infection
Hypercalcaemia
Amyloidosis
Miscellaneous