Cryoglobulins are immunoglobulins, which reversibly precipitate upon exposure to cold temperature and redissolve at high temperature (above 37 °C). Brouet et al. classified cryoglobulinemia by the components of the cryoprecipitate: Type I, isolated monoclonal immunoglobulins, type II, a monoclonal component, usually IgM possessing activity toward polyclonal immunoglobulins, usually IgG, and type III, polyclonal immunoglobulins. We proved 34 monoclonal cryoglobulins in our series of 3049 paraproteins. The most frequent (18x) were paraproteins IgM (15x IgM-kappa, 2x IgM-lambda and 1x IgM type of light chains non detected), 13x paraproteins IgG (6x IgG-kappa and 7x IgG-lambda), 1x double paraproteins IgA-kappa + IgG-lambda, 1x freemonoclonal light chains lambda and 1x mixed cryoglobulinemia (type II) - paraprotein IgM-kappa with polyclonal IgG. We determined concentration, cryocrit, viscosity and temperature of cryoprecipitation for every monoclonal cryoglobulin.

        Key words: monoclonal cryoglobulin, paraprotein, cryocrit.