Myeloma cast nephropathy, also referred to as light-chain cast nephropathy, is the formation of plugs (

urinary casts Urinary casts are microscopic cylindrical structures produced by the kidney and present in the urine in certain disease states. They form in the distal convoluted tubule and collecting ducts of nephrons, then dislodge and pass into the urine, wher ...

) in the

kidney tubules The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure ca ...

from free

immunoglobulin An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

light chains leading to

kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

in the context of

multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, an ...

. It is the most common cause of kidney injury in myeloma. In myeloma cast nephropathy, filtered κ or λ light chains that bind to

Tamm-Horsfall protein Uromodulin (UMOD), also known as Tamm–Horsfall protein (THP), is a Zona pellucida-like domain-containing glycoprotein that in humans is encoded by the ''UMOD'' gene. Uromodulin is the most abundant protein excreted in ordinary urine. Gene T ...

precipitate in the kidney's tubules.

Hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalcemi ...

and low fluid intake contribute to the development of casts. Myeloma cast nephropathy is considered to be a medical emergency because if untreated, it leads to irreversible kidney failure. It is diagnosed by histological examination of kidney

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...

References

{{Reflist Nephrology

See also

References