Distinctly different expression of cytokines and chemokines in the lungs of two H5N1 avian influenza patients

The pathogenesis of human H5N1 influenza remains poorly understood and controversial. 'Cytokine storm' has been hypothesized to be the main cause of the severity of this disease. However, the significance of this hypothesis has been called into question by a recent report, which demonstrates that inhibition of the cytokine response did not protect against lethal H5N1 influenza infection in mice. Here we showed discrepant findings in two adult H5N1 autopsies and a fetus obtained at autopsy which also raise doubt about this hypothesis. Antigens of 10 cytokines/chemokines which were found to be significantly elevated in previous H5N1-infected patients and in vitro experiments, and mRNA of eight of these, were absent from the lungs of a pregnant woman and her fetus. In contrast, antigens of seven cytokines/chemokines and mRNA of six of these were found to be increased in the lungs of a male autopsy. The cells expressing these cytokines and chemokines were identified as type II pneumocytes, bronchial epithelial cells, macrophages and vascular endothelial cells. Levels of cytokines and chemokines in the serum of the male case were also significantly higher than those of infectious (infection other than by H5N1) and non-infectious controls. In comparison with results from our previous study, it appeared that the male case had increased cytokine/chemokine expression but reduced viral load, while the pregnant female had diminished cytokine/chemokine expression but a significantly increased viral load in the lungs. These disparate findings in these two cases suggest that 'cytokine storm' alone could not be a sufficient explanation for the severe lung injury of this newly emerging disease.

Immunoglobulin G expression and its potential role in primary and metastatic breast cancers

Recently immunoglobulin G (IgG) was found to be produced by neoplasms and promote tumor growth in cancer cell lines and animal models. To investigate the pathophysiological significance of cancer-produced IgG in breast cancer, we examined the expressions of IgG in 68 breast cancers including 40 primary cancers without metastasis and 28 cancers with axillary lymph node metastases. IgG gene expression was detected in all these samples. We found that IgG-expressing cancer cells were predominantly located in the periphery of the primary cancer nest and that these cells showed more cellular atypia and nuclear pleomorphism. We also found that the abundance of IgG-expressing cancer cells was higher and the cells were more evenly distributed in the metastatic cancer cells than that in the primary lesion. These findings suggest that IgG-expressing breast cancer cells have a more aggressive biological behavior than the IgG negative cancer cells and it could be an indicator for progression and metastasis of the disease. Co-localization of IgG and C1q complement was detected in both primary and metastatic lesions implying that immune complexes might be formed in situ. We speculate that such immune complexes might facilitate immune escape of cancer cells. Our findings suggest that locally produced IgG plays important roles in breast cancer, and may serve as a potential therapeutic target.