By Disease Name > Cryoglobulinemia

Cryoglobulinemia

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two categories:

type I a single monoclonal immunoglobulin
type II (mixed) more than one class of immunoglobulin, usually IgM and IgG with the IgM having rheumatoid factor activity directed against IgG molecules  (classified as either “essential” meaning idiopathic;  or "secondary" to CTD or infection)

Monoclonal CRYOGLOBULINEMIA

are essentially monoclonal proteins with abnormal thermal behavior
usually detected in patients with plasma cell malignancies (e.g. multiple myeloma, CLL, Waldenstroms macroglobulinemia)
histology = amorphous eosinophilic material in the vessel lumen (=intravascular deposits of cryoglobulins) (no LCV)

mixed CRYOGLOBULINEMIA

represent cold-precipitable immune complexes (reflecting the fact that low temperatures increase the stability of Ag-Ab interactions and enhance precipitation)
in patients with autoimmune disease (e.g. RA, SLE, Sjögrens) or chronic infection (especially Hepatitis C)
histology = LCV
the most frequent type of mixed cryoglobulin is IgM-IgG, in which IgM is a “rheumatoid factor

 

Essential mixed cryoglobulinemia:

= there is no detectable autoimmune, lymphoproliferative, or infectious disease present
~ 50% of cases
characterized by chronic course with intermittent palpable purpura, polyarthralgia, Raynauds, and occasionally glomerulonephritis.

 

hmtoggle_plus1theory:
it is believed that, at least in some cases, the IgM antibody is directed to determinants expressed by IgG antibodies bound to an antigen (e.g. an unknown viral antigen)
it is believed that this mechanism, anti-viral IgG combined with an IgM anti-antibody, accounts for over 50% of the cases of essential or idiopathic cryoglobulinemia

 

hmtoggle_plus1collection for cryos
blood is drawn and clotted at 37ºC, serum is immediately separated, without cooling, and immediately after centrifugation, 5-10ml of serum are placed in a refrigerator at 4-8°C
the serum will be examined daily, up to 72 hours for appearance of a precipitate (i.e. cryos)

 

clinical ddx:  can look Schamberg's-like (Cayenne-pepper) vs. Waldenstrom's hyperglobulinemic purpura (Cayenne pepper)

(cryos can look like BPP with small ulcers)