Reduction of natural killer but not effector CD8 T lymphocytes in three consecutive cases of severe/lethal H1N1/09 influenza A virus infection.
BACKGROUND
The cause of severe disease in some patients infected with pandemic influenza A virus is unclear.


RESULTS
We present the cellular immunology profile in the blood, and detailed clinical (and post-mortem) findings of three patients with rapidly progressive infection, including a pregnant patient who died. The striking finding is of reduction in natural killer (NK) cells but preservation of activated effector CD8 T lymphocytes; with viraemia in the patient who had no NK cells. Comparison with control groups suggests that the reduction of NK cells is unique to these severely ill patients.


CONCLUSIONS
Our report shows markedly reduced NK cells in the three patients that we sampled and raises the hypothesis that NK may have a more significant role than T lymphocytes in controlling viral burden when the host is confronted with a new influenza A virus subtype.
Denney
Laura
L
Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, United Kingdom.
Aitken
Celia
C
Li
Chris Ka-Fai
CK
Wilson-Davies
Eleri
E
Kok
Wai Ling
WL
Clelland
Colin
C
Rooney
Kevin
K
Young
Duncan
D
Dong
Tao
T
McMichael
Andrew J
AJ
Carman
William F
WF
Ho
Ling-Pei
LP
D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D017809:Fatal Outcome; D005260:Female; D005615:Freezing; D006262:Health; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000097:blood / Q000000981:diagnostic imaging / Q000276:immunology* / Q000821:virology*; D007694:Killer Cells, Natural / Q000276:immunology* / Q000821:virology; D008168:Lung / Q000276:immunology / Q000473:pathology / Q000821:virology; D008297:Male; D008875:Middle Aged; D011180:Postmortem Changes; D011247:Pregnancy; D012367:RNA, Viral / Q000097:blood; D013902:Radiography, Thoracic; D055815:Young Adult
D012367:RNA, Viral