}Type I: isolated monoclonal immunoglobulin, generally either IgM or IgG               

}• Type II cryoglobulins: mixture of monoclonal IgM and polyclonal IgG. The IgM component of type II cryoglobulins has rheumatoid factor activity (ie, these immunoglobulins bind to the Fc portion of IgG).

• Type III cryoglobulins:mixture of polyclonal IgM and IgG.