Other distributions include localized areas on the upper body or over several areas of the body.With treatment, the lesions typically resolve in weeks to months and leave behind flat spots that are darker than the surrounding skin (see "Postinflammatory hyperpigmentation" on "Hyperpigmentation"). A portion of cases may be persistent or recurrent. This tends to occur when the vasculitis is associated with chronic conditions such as connective tissue diseases. Associated symptoms
In most cases skin lesions do not cause symptoms, however itching, burning, or pain may occur.Frequently reported symptoms include mild fever, muscle pain, joint pain, or an overall feeling of discomfort. Additional symptoms depend on the cause of the vasculitis and if other organ systems are involved. For example, if the vasculitis is a manifestation of Henoch–Schönlein purpura, individuals may also experience abdominal pain or blood in the urine. Cause
Cutaneous vasculitis can have various causes including but not limited to medications, bacterial and viral infections or allergens. It is estimated that 45–55% of cases are idiopathic, meaning the cause is unknown. In cases where a cause can be determined, medications and infectious pathogens are most common in adults, while IgA vasculitis (Henoch–Schönlein purpura) frequently affects children. Other etiologies include autoimmune conditions and malignancies, usually hematologic (related to the blood). The small vessels in the skin affected are located in the superficial dermis and include arterioles (small arteries carrying blood to capillaries), capillaries, and venules (small veins receiving blood from capillaries). In general, immune complexes deposit in vessel walls leading to activation of the complement system.
These models display abnormally low amounts of cells or necrosis of decidua.In humans, elevated levels of IFN-γ have been associated with increased risk of miscarriage. Correlation studies have observed high IFN-γ levels in women with a history of spontaneous miscarriage, when compared to women with no history of spontaneous miscarriage. Additionally, low-IFN-γ levels are associated with women who successfully carry to term. It is possible that IFN-γ is cytotoxic to trophoblasts, which leads to miscarriage. However, causal research on the relationship between IFN-γ and miscarriage has not been performed due to ethical constraints. Production
Recombinant human IFN-γ, as an expensive biopharmaceutical, has been expressed in different expression systems including prokaryotic, protozoan, fungal (yeasts), plant, insect and mammalian cells. Human IFN-γ is commonly expressed in Escherichia coli, marketed as ACTIMMUNE®, however, the resulting product of the prokaryotic expression system is not glycosylated with a short half-life in the bloodstream after injection; the purification process from bacterial expression system is also very costly. Other expression systems like Pichia pastoris did not show satisfactory results in terms of yields. Therapeutic use
Interferon-γ 1b is approved by the U.S. Food and Drug Administration to treat chronic granulomatous disease (CGD) and osteopetrosis. The mechanism by which IFN-γ benefits CGD is via enhancing the efficacy of neutrophils against catalase-positive bacteria by correcting patients oxidative metabolism.It was not approved to treat idiopathic pulmonary fibrosis (IPF).