krioprecipitaati

Krioprecipitaatio, also known as cryoprecipitation, is a phenomenon where certain proteins or other substances in a liquid, typically blood plasma, precipitate out when the sample is cooled to low temperatures, usually below 4 degrees Celsius. This precipitation is reversible; the substances redissolve when the sample is warmed back to room temperature. The most common and clinically significant krioprecipitate is krioglobulin, which refers to immunoglobulins that precipitate in the cold.

Krioglobulins can be classified into three main types based on their composition and how they form. Type I krioglobulins are monoclonal immunoglobulins, often IgG or IgM, that precipitate on their own. Type II krioglobulins are mixed, consisting of a monoclonal immunoglobulin (usually IgG) complexed with polyclonal immunoglobulins (usually IgM). Type III krioglobulins are also mixed but involve polyclonal immunoglobulins of different classes.

The presence of krioglobulins can lead to a variety of clinical symptoms, collectively known as krioglobulinemia. These symptoms often arise from the obstruction of small blood vessels by the precipitated proteins, leading to reduced blood flow. Common manifestations include Raynaud's phenomenon, purpura, arthralgias, peripheral neuropathy, and renal involvement. The underlying conditions associated with krioglobulinemia are diverse and can include lymphoproliferative disorders, autoimmune diseases like Sjögren's syndrome and rheumatoid arthritis, and chronic infections such as hepatitis C virus infection. Diagnosis typically involves a blood test where the serum is cooled and observed for precipitate formation.