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, whe ...

) in the kidney tubules from free

immunoglobulin An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, includin ...

light chains leading to

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), 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 fa ...

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 antibody, antibodies. Often, no symptoms are noticed initially. As it progresses, bone ...

. 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),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. The human UMOD gene is loc ...

precipitate in the kidney's tubules.

Hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range for total calcium 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 def ...

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, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample ...

References

{{Pathology-stub} Nephrology

See also

References