|Classification and external resources|
Cryoglobulinemia is a medical condition in which the blood contains large amounts of cryoglobulins - proteins (mostly immunoglobulins themselves) that become insoluble at reduced temperatures. This should be contrasted with cold agglutinins, which cause agglutination of red blood cells. Cryoglobulins typically precipitate at temperatures below normal body temperature (37°C) and will dissolve again if the blood is heated. Cryoglobulinemia can be associated with various diseases such as multiple myeloma and hepatitis C infection. Cryoglobulins usually consist of IgM directed against the Fc region of IgG.
Cryoglobulinemia is classically grouped into three types according to the Brouet classification. Type I is most commonly encountered in patients with a plasma cell dyscrasia such as multiple myeloma or Waldenström macroglobulinemia. Types II and III are strongly associated with infection by the hepatitis C virus. Types III are strongly associated with autoimmune disease such as systemic lupus erythematosus and rheumatoid arthritis.
There are three different types of cryoglobulins that have been observed to form in the blood.
|Type I||isolated monoclonal immunoglobulins||10–15% of the total cases||These are composed of a single monoclonal immunoglobulin paraprotein (usually IgM). Sometimes, these are represented by light chains only and can be extracted from the urine; or, they may accumulate in blood serum in the event of renal failure.|
|Type II||immunocomplexes formed by monoclonal IgM||50–60% of reported cases||They usually have a polyclonal component, usually IgG, and a monoclonal component, usually IgM or IgA, which has an RF function. The IgM can recognize intact IgG or either the Fab region or Fc region of IgG fragments. This is why most type II cryoglobulins are IgM–IgG complexes.|
|Type III||immunocomplexes formed by polyclonal IgM||25–30% of the reported cases||These have very similar function to the type II cryoglobulins; however, they are composed of polyclonal IgM and IgG molecules.|
Types II and III have rheumatoid factor (RF) activity and bind to polyclonal immunoglobulins. These two types are referred to as mixed cryoglobulinemia (MC). When the temperature is raised, the precipitated cryoglobulins will dissolve back into the serum.
In 2006 it was discovered that there are unusual cryoglobulins that show a microheterogeneous composition, with an immunochemical structure that cannot be fit into any of the classifications. A classification of a type II-III variant has been proposed because they are composed of oligoclonal IgMs with traces of polyclonal immunoglobulins
These proteins may be present in Mycoplasma pneumonia, post streptococcal glomerulonephritis, multiple myeloma, certain leukemias, primary macroglobulinemia, and some autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. This is also found as a symptom in 35% of chronic hepatitis C infections. It can also occur in hepatitis B and human immunodeficiency virus infections. It is important to note that these two different, yet highly representative, clinical syndromes generally reflect different types of underlying CG:
- Hyperviscosity is typically associated with CG due to hematological malignancies and monoclonal immunoglobulins.
- "Meltzer's triad" (purpura, arthralgia and myalgia) is generally seen with polyclonal CGs seen in essential, viral, or connective tissue disease-associated CG.
- "Cryoglobulinemia" at Dorland's Medical Dictionary
- Peveling-Oberhag, J.; Arcaini, L.; Hansmann, M. L.; Zeuzem, S. (2013). "Hepatitis C-associated B-cell non-Hodgkin lymphomas. Epidemiology, molecular signature and clinical management". Journal of Hepatology 59 (1): 169–177. doi:10.1016/j.jhep.2013.03.018. PMID 23542089.
- Template:Cite url=http://emedicine.medscape.com/article/329255-overview
- Brouet JC, Clauvel JP, Danon F, Klein M, Seligmann M (1974). "Biologic and clinical significance of cryoglobulins. A report of 86 cases". Am. J. Med. 57 (5): 775–88. doi:10.1016/0002-9343(74)90852-3. PMID 4216269.
- Ferri C, Zignego AL, Pileri SA (2002). "Cryoglobulins". J. Clin. Pathol. 55 (1): 4–13. doi:10.1136/jcp.55.1.4. PMC 1769573. PMID 11825916.
- "Cryoglobulin" at Dorland's Medical Dictionary
- Tedeschi A, Baratè C, Minola E, Morra E (2007). "Cryoglobulinemia". Blood Rev. 21 (4): 183–200. doi:10.1016/j.blre.2006.12.002. PMID 17289231.
- Tissot JD, Schifferli JA, Hochstrasser DF et al. (1994). "Two-dimensional polyacrylamide gel electrophoresis analysis of cryoglobulins and identification of an IgM-associated peptide". J. Immunol. Methods 173 (1): 63–75. doi:10.1016/0022-1759(94)90284-4. PMID 8034987.
- Franco Dammacco, and Domenico Sansonno (September 12, 2013). "Review Article: Therapy for Hepatitis C Virus–Related Cryoglobulinemic Vasculitis". N Engl J Med 369 (11): 1035–1045. doi:10.1056/NEJMra1208642. PMID 24024840.
- Pascual M, Perrin L, Giostra E, Schifferli JA (1990). "Hepatitis C virus in patients with cryoglobulinemia type II". J. Infect. Dis. 162 (2): 569–70. doi:10.1093/infdis/162.2.569. PMID 2115556.
- Liang TJ (May 2009). "Hepatitis B: the virus and disease". Hepatology (Baltimore, Md.) 49 (5 Suppl): S13–21. doi:10.1002/hep.22881. PMC 2809016. PMID 19399811. Retrieved 2011-12-08.
- Monti G, Galli M, Invernizzi F et al. (February 1995). "Cryoglobulinaemias: a multi-centre study of the early clinical and laboratory manifestations of primary and secondary disease. GISC. Italian Group for the Study of Cryoglobulinaemias". QJM 88 (2): 115–26. PMID 7704562.
|Wikimedia Commons has media related to Cryoglobulinemia.|