APST full form in medical term is an Autologous Plasma skin test, which is performed to diagnose chronic autoimmune urticaria with histamine, autoantibodies-releasing aspects, and coagulation elements, especially thrombin. Chronic Spontaneous Urticaria is the most common condition with incomplete, complication-fathomed etiopathogenesis. CSU is meant as an almost daily or daily occurrence of wheals for approx six weeks without or with angioedema.
However, the long-term results and disease severity of APST are still unclear. In contrast, the primary purpose of APST is to predict the urticaria signs seriousness and long-lasting results among CSU (chronic spontaneous urticaria) patients.
The Autologous Plasma Skin test includes an intradermal injection of autologous plasma. It is practical and straightforward to use in practice and has been used to help test auto-immune urticaria.
According to scientists and researchers, APST provides more accurate and positive results than ASST, as plasma comprises coagulation aspects and complements, which are ingested in the development of Clots in ASST. Hence there are fewer positive results. However, the APST test for CSU is done per the standard guidelines. People going for APST are advised to stop Doxepin, Antihistamine, and Steroids 2 days, three weeks, and one week respectively, before the test.