Idiopathic hypereosiophilic syndrome
The idiopathic hypereosinophilic syndrome is a disorder characterized by hypereosiophilia that is associated with eosinophil-based tissue or organ damage. While almost any organ or tissue may be damaged, the lung, skin, heart, blood vessels, sinuses, kidneys, and brain are the most commonly affected. The World Health Organization restrict this diagnosis to cases which have no well-defined cause. That is, all cases of secondary (i.e. reactive) eosinophilia (including lymphocyte-variant hypereosinophilia) and primary hypereosinophilia (including chronic eosinophilic leukemia (NOS), clonal eosinophilia, and hypereosinophilia associated with hematological malignancies) are excluded from this diagnosis. Secondary hypereosinophilia
Secondary (or reactive) eosinophilias are non-clonal increases in blood eosinophil levels caused by an underlying disease. The pathogenesis of the hypereosinophilia in these diseases is thought to be the release of one or more cytokines (e.g. granulocyte macrophage colony stimulating factor, interleukin 3, interleukin 5) that: a) cause bone marrow precursor cells, i.e. CFU-Eos, to proliferate and mature into eosinophils; b) promote release of bone marrow eosinophils into the circulation, c) stimulate circulating eosinophils to enter tissues and release tissue-injuring agents. These cytokines may be released by the diseased cells or the diseased cells may cause the release of these cytokines by non-diseased cells. Primary disorders associated with and known or presumed to cause hypereosinophilia or eosinophilia are given below. Infections
Helminths are common causes of hypereosinophilia and eosinophilia in areas endemic to these parasites. Helminths infections causing increased blood eosinophil counts include: 1) nematodes, (i.e. Angiostrongylus cantonensis and Hookworm infections), ascariasis, strongyloidiasis trichinosis, visceral larva migrans, Gnathostomiasis, cysticercosis, and echinococcosis; 2) filarioidea, i.e.
Cryofibrinogenemia refers to a condition classified as a fibrinogen disorder in which a persons blood plasma is allowed to cool substantially (i.e. from its normal temperature of 37 °C to the near-freezing temperature of 4 °C), causing the (reversible) precipitation of a complex containing fibrinogen, fibrin, fibronectin, and, occasionally, small amounts of fibrin split products, albumin, immunoglobulins and other plasma proteins. Return of plasma to more normal temperature resolubilizes the precipitate. Cryofibrinogenemia may occur in individuals that have no obvious evidence of precipitate-induced tissue damage (asymptomatic cryofibrinogenemia), or in consequence of cryofibrinogen precipitation resulting in blood clots in small and medium size arteries and veins. When occurring in association with another causual disease, cryofibrinogenemic disease is referred as secondary cryofibrinogenemia; in the absence of such an association, it is referred to as primary cryofibrinogenemia. Cryofibrinogen precipitation
The reasons for the cold temperature-induced in vitro as well as the in vivo precipitation of the fibrinogen-containing complex is unknown. The fibrinogen involved in precipitate formation appears to have a normal structure. This separates cryofibrinogenemia from two pathological blood-clotting/bleeding diseases that can mimic cryofibrinogenemia but are due to structurally abnormal fibrinogen viz., dysfibrinogenemia and hypodysfibrinogenemia. Based on in vitro studies, three causes have been hypothesized for the precipitate formed in cryofibrinogenemia. 1) The blood and plasma of individuals with cryofibrinogenemia lack the fibrinolysis activity that normally degrades and thereby resolubilizes the precipitate.