Through the looking crystal: clarifying the pathogenesis and laboratory work-up of cryocrystalglobulinaemia

Cryoglobulins are immunoglobulins that precipitate or gel out of serum at temperatures less than 37°C and resolubilise on warming.1 Cryoglobulinaemia can cause vascular sludging or immune-mediated inflammation that classically presents with Meltzer’s triad of pupura, arthralgia and weakness.2 Cryocrystal formation is rare and can induce occlusive vasculopathy, thrombosis and inflammation.3 The aetiology of cryoglobulinaemia commonly includes infections, autoimmune diseases and haematological malignancies.2 Cryoglobulins are classified into three types based on clonality and immunoglobulin typing.4 Type 1 consists of monoclonal immunoglobulin only; in contrast to mixed cryoglobulinaemia (types 2 and 3). Type 2 comprises monoclonal IgM and polyclonal IgG, and type 3 is constituted by polyclonal IgM and IgG. The IgM component of mixed cryoglobulinaemia frequently demonstrates rheumatoid factor activity, which enables IgM to bind to the fragment crystallisable (Fc) region of IgG, and form immune antibody–antigen complexes.2...
Source: Journal of Clinical Pathology - Category: Pathology Authors: Tags: JCP Education Grand rounds commentary Source Type: research