LAUSR

Immune thrombocytopenia is an isolated thrombocytopenia not related to other etiologies of thrombocytopenia.1 The diagnosis relies mainly on exclusion of other conditions.2,3 The incidence of ITP among adults has been estimated to be 3.3 per 100,000 persons in Europe according to a review study in 2009.4 ITP may be induced by drugs.2 In this type of ITP, a drug induces production of antibodies against platelets and causes destruction and reduction of platelets.2 This is usually transient and improves after withdrawal of the offending drug.1,2 Cinnovex is a b-interferon-1α widely used in RRMS patients in Iran. Cinnovex is a biosimilar form of Avonex.5 Various studies have shown its efficacy in RRMS patients in Iran.5,6 The frequency of thrombocytopenia ranges from 0.1% to 8% in patients receiving b-interferon-1α (http://www.cinnagen.com/ Product.aspx?t=2&l=1&Id=45&f=2#ti tle32). Thrombocytopenia has also been reported in patients receiving Cinnovex in Iran (Product Information. Avonex (interferon beta-1a).” Biogen, Cambridge, MA.) This paper reports a case of severe immune thrombocytopenia (ITP) in a RRMS patient receiving b-interferon-1α (Cinnovex).