A crystal of<unk> .<unk>  is a monoclonal globulin<unk>  or immunoglobulin light chain found in the urine, with a molecular weight of 22–24 kDa. Detection of<unk>  may be suggestive of multiple myeloma or Waldenström's macroglobulinemia.<unk> s are particularly diagnostic of multiple myeloma in the context of target organ manifestations such as kidney failure, lytic (or "punched out") bone lesions, anemia, or large numbers of plasma cells in the bone marrow of patients.<unk> s are present in 2/3 of multiple myeloma cases. The<unk> s are immunoglobulin light chains (paraproteins) and are produced by neoplastic plasma cells. They can be kappa (most of the time) or lambda. The light chains can be immunoglobulin fragments or single homogeneous immunoglobulins. They are found in urine as a result of decreased kidney filtration capabilities due to kidney failure, sometimes induced by hypercalcemia from the calcium released as the<unk>  are destroyed ,dehydration due to polyurea, amyloidosis or from the light chains themselves. The light chains have historically been detected by heating a urine specimen (which causes the<unk>  to precipitate) and now by electrophoresis of concentrated urine. More recently, serum free light chain assays have been utilised in a number of published studies which have indicated superiority over the urine tests, particularly for patients producing low levels of monoclonal free light chains, as seen in nonsecretory multiple myeloma and AL amyloidosis.
Bence Jones protein
Keratic precipitate
Anti-glomerular basement membrane antibody
Anti-AQP4 disease
Beta-2 microglobulin
Iminoglycinuria
Oligoclonal band
Cryoglobulinemia