Thrombocytopenic Purpura after the Administration of an Influenza Vaccine in a Patient with Autoimmune Liver Disease

! 1/20); IgG, 3,180 mg/dl; IgM, 1,231 mg/dl (normal ranges: IgG, 870–1,700 mg/dl; IgM, 35–220 mg/dl). Moreover, anti-hepatitis B surface antibody and anti-hepatitis C antibody were negative. The ultrasound examination findings did not show any evidence of a specific disease causing the abnormal liver function, such as a liver tumor. She was diagnosed as having AILD and was treated with ursodeoxycholic acid (UDCA; 10 mg/kg, daily). Three months later, her liver function returned to almost normal levels (AST, 38 IU/l; ALT, 20 IU/l). On January 23, 2006, she presented at an outpatient clinic with epistaxis and petechiae on her lower extremities. No evidence of lymphadenopathy or hepatosplenomegaly was noted. She had received an influenza vaccine (Influenza HA Vaccine ‘Kitaken’) 1 week before the onset of her symptoms. Upon admission, her platelet count was 5 ! 10 3 /ml. The remainder of her differential blood counts and a coDear Sir, Influenza, a contagious viral disease, can usually be prevented by receiving an influenza vaccine. Almost 15 million doses of influenza vaccine were produced in Japan for the 2003–2004 influenza season. Although serious side effects from the influenza vaccine are extremely rare, the influenza vaccine, as all vaccines, may sometimes induce or trigger autoimmune reactions in susceptible individuals (e.g., the development of Guillain-Barre syndrome) [1] . This report describes a patient with autoimmune liver disease (AILD) who developed idiopathic thrombocytopenic purpura (ITP) after receiving an influenza vaccine. In August 2005, a 75-year-old female living in Tokyo was referred to the Jikei Daisan Hospital because of abnormal liver function test results. She had no history of daily alcohol consumption or obesity. The physical examination was unremarkable. Her laboratory data showed: aspartate aminotransferase (AST), 70 IU/l; alanine aminotransferase (ALT), 40 IU/l; lactate dehydrogenase (LDH), 222 IU/l; alkaline phosphatase (ALP), 266 IU/l;  -glutamyl triphosphate ( -GTP), 200 IU/l, and total bilirubin (T-Bil), 1.0 mg/dl (normal ranges: AST, 10–33 IU/l; ALT, 6–35 IU/l; LDH, 130–235 IU/l; ALP, 96–300 IU/l; -GTP, 9–27 IU/l; T-Bil, 0.2–1.2 mg/dl). The peripheral blood cell counts were as follows: Published online: June 24, 2008