Influenza A H1N1 pneumonia in a patient with hairy-cell leukemia.

Severe pandemic influenza A virus (H1N1) infection is associated with risk factors such as pregnancy, obesity and immunosuppression. Immunocompromised patients are at increased risk of more severe or prolonged infection. We report a case of a hairy cell leukemia patient with H1N1 pneumonia which caused severe and prolonged illness. H1N1 virus pneumonia with meticillin-resistant Staphilococcus Aerues (MRSA) coinfection causing Acute Lung Injury (ALI) was treated with a double-dose of osentamyvir, a high dose of teicoplanin and a low dose of corticosteroids. Haematological findings included leucopenia, neutropenia, lymphopenia, reduction of γ-globulins and natural killer (NK) cells. Reduction of NK and γ-globulins may explain the development of severe illness and the prolonged illness Neutropenia may explain the MRSA co-infection. Lymphopenia is directly associated with virus action and is considered to be a marker of the swine influenza in adults.