A case of novel swine influenza A (H1N1) pneumonia complicated with virus-associated hemophagocytic syndrome

Abstract

Influenza related to complications such as pneumonia and encephalitis have sporadically been reported. However, influenza A (H1N1)-virus-associated hemophagocytic syndrome (VAHS) has rarely been reported. A 39-year old woman complained of high fever and was referred to us. Chest infiltrations in both lungs and a positive polymerase chain reaction (PCR) for novel swine origin influenza A (H1N1) in bronchial alveolar lavage fluid (BALF) specimen was confirmed and she was diagnosed with influenza A (H1N1) pneumonia. Pancytopenia was found, and hemophagocytic syndrome (HPS) was diagnosed by bone marrow aspiration. Following intravenous administration of antiflu drug and combination therapy of steroid pulse and erythromycin IV, the patient’s respiratory dysfunction and lab data gradually improved and she was discharged on day 21. Whereas secondary HPS related to viral infections such as Epstein–Barr virus, cytomegalovirus, and human herpesvirus type 6 are commonly seen, H1N1 pneumonia complicated with secondary VAHS is rare.

Influenza-Associated Hemophagocytic Syndrome in Adults: Case Report and Review

“…Seasonal (H3N2), avian (H5N1), and swine (non-pandemic) (H1N1) influenza have all been associated with fatal cases of HPS in immunocompromised and in immunocompetent hosts [5][6][7][8][9][10][11][12][13]. It is a rare disease whose exact incidence is not known.…”

“…Only English language papers were reviewed. This search revealed 15 other cases of adults with influenza A associated HPS [5][6][7][8][9][10][11][12][13] and a prospective observational study carried out in 25 critically ill patients with VAHS secondary to influenza H1N1 which was not included in the analysis because of incomplete individual patient data [14].…”

Um caso de pneumonia por vírus parainfluenza 3 simulando pneumonia por influenza tratada com sucesso

“…Although she tested negative for influenza A and influenza B antibodies, the patient tested are effective in reducing pulmonary lesions and suppressing cytokines, leading to a shutdown in macrophage activation. (6)(7)(8) It is reasonable to assume that, in the present case, erythromycin had an immunomodulatory effect rather than an antimicrobial effect when combined with a high dose of prednisolone.…”

“…It has been reported that macrolides can be effective for severe inflammation, since it is evident that they decrease neutrophil chemotaxis and infiltration into the respiratory epithelium, downregulating adhesion molecule expression and enhancing neutrophil apoptosis. (6,7) In addition, animal studies have shown that high doses of steroids …”

Hemophagocytic syndrome due to infection by H1N1 influenza virus

“…The treatment, either primary or secondary, includes protocols with immunosuppressive pharmacotherapy (Etoposide, dexamethasone, cyclosporin A), 15,16 prophylactic antimicrobial therapy, and fresh frozen plasma or cryoprecipitated (if there is acute bleeding or platelet count <50×109/L) 9 , alongside an adequate evaluation of cardiac function due to the risk of myocardial injury caused by inflammation or drug toxicity.…”