Paraproteinemia

What it means

An abnormal immunoglobulin or part of an Ig (light chain) in the circulation. Paraproteins are typically produced by a clonal population of B-cell derived plasma cells.

A paraprotein is a monoclonal immunoglobulin or light chain present in the blood or urine; it is produced by a clonal population of mature B cells, most commonly plasma cells. Plasma cell disorders can be considered as a spectrum of conditions ranging from monoclonal gammopathy of undetermined significance (MGUS), through asymptomatic, to symptomatic myeloma. The frequency of paraprotein-associated heavy chains is IgG, IgA, IgM, IgD (in that order). Light chains may be kappa or lambda. Paraproteins are associated with both malignant and nonmalignant conditions and may lead to complications including neuropathy and nephropathy.

Rare diseases that can present with this8

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Monoclonal hypergammaglobulinemia