Severe novel influenza A (H1N1) infection in cancer patients

Abstract

Background: The natural history and consequences of severe H1N1 influenza infection among cancer patients are not yet fully characterized. We describe eight cases of H1N1 infection in cancer patients admitted to the intensive care unit of a referral cancer center.

Patients and methods: Clinical data from all patients admitted with acute respiratory failure due to novel viral H1N1 infection were reviewed. Lung tissue was submitted for viral and bacteriological analyses by real-time RT-PCR, and autopsy was conducted on all patients who died.

Results: Eight patients were admitted, with ages ranging from 55 to 65 years old. There were five patients with solid organ tumors (62.5%) and three with hematological malignancies (37.5%). Five patients required mechanical ventilation and all died. Four patients had bacterial bronchopneumonia. All deaths occurred due to multiple organ failure. A milder form of lung disease was present in the three cases who survived. Lung tissue analysis was performed in all patients and showed diffuse alveolar damage in most patients. Other lung findings were necrotizing bronchiolitis or extensive hemorrhage.

Conclusions: H1N1 viral infection in patients with cancer can cause severe illness, resulting in acute respiratory distress syndrome and death. More data are needed to identify predictors of unfavorable evolution in these patients.

Figure 1.

Radiographic findings in patients admitted in intensive care unit with swine-origin influenza A virus infection. The first panel shows a radiological sequence of three X-rays at admission (A), 12 h (B) and 24 h (C) after admission of a patient who developed progressively respiratory failure needing mechanical ventilation. The second panel shows X-rays at admission (D), 4 h (E) and 12 h (F) after admission of a patient who developed respiratory failure, needing mechanical ventilation.

Figure 2.

Chest computerized tomography of a patient who showed a milder form of lung disease (A), improving in intensive care unit after noninvasive ventilation (B).

Figure 3.

Representative photomicrographs of pulmonary and extrapulmonary changes in cancer patients with fatal H1N1 infection. A to C show different patterns of pulmonary involvement. (A) Exudative diffuse alveolar damage (DAD) with numerous hyaline membranes (arrows) within alveolar spaces. (B) Extensive lung hemorrhage associated with DAD. (C) Necrotizing bronchiolitis. The bronchiole (Br) is partially filled with necrotic epithelial and inflammatory cells. (D) Bronchopneumonia. The alveolar spaces (Alv) are filled with dense infiltration of macrophages and neutrophils. (E) Lung metastasis (M) from primary breast cancer, P = pulmonary tissue. (F) Spleen with depleted white pulp (arrow) and expanded red pulp. Scale bars: A–E: 100 μm, F: 50 μm.