Allergies cause heaps of trouble. Some people suffer the nuisance of seasonal hay fever, snuffling and sneezing as pollen flows

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问题     Allergies cause heaps of trouble. Some people suffer the nuisance of seasonal hay fever, snuffling and sneezing as pollen flows through the air. Others react to materials such as metals, developing unpleasant rashes at their very touch. And some sorry souls go into shock at the mere presence of certain foods, particularly peanuts and shellfish.
    The cause in each case is an oversensitive immune system that is reacting to harmless materials as well as to the pathogens it is supposed to be fighting. This creates annoying and sometimes life-threatening symptoms. Chronically over-reactive immune systems may not, though, be an entirely bad thing. Another role played by the immune system is to destroy malignant tumours before they take hold—and work carried out recently by Annette Wigertz of the Karolinska Institute, in Stockholm, and her colleagues suggests that the immune systems of those with allergies may be particularly good at this. However, in a nice example of the way that one set of data is sometimes capable of divergent—indeed, opposite—interpretations, she may instead have discovered a clue about how cancers shut down immune systems in order that they themselves may prosper.
    This Manichean finding came after Dr. Wigertz and her team interviewed 1,527 people with gliomas (a type of brain turnout) in Denmark, Finland, Norway, Sweden and the south-east of England. The researchers asked the patients in question whether they had a history of allergies, and then compared the results with those for 3,309 otherwise similar individuals who did not have brain tumours. As Dr. Wigertz reports in the American Journal of Epidemiology, the tumour-free were, indeed, more likely to suffer from allergies. The presence of an allergy was associated with a 30% reduction in the likelihood of having a glioma.
    This was not all that surprising. Previous research had detected similar inverse correlations between allergies and brain tumours, suggesting that a welcome side effect of allergy was resistance to cancer. But this new study went further. It looked carefully at the time in the patients’ lives when their allergies were active, and it found that this timing was crucial. Dr. Wigertz noted that the absence of allergy was correlated with the time when a glioma first formed. That was true even in people who had previously had allergies which had then cleared up.
    Awkwardly, this result is open to two rather different interpretations. The optimistic explanation is that the hyperactive immune system associated with allergy does, indeed, protect against turnouts. In that case, the coincidence was caused by turnouts taking advantage, as it were, of the reduced immune surveillance that accompanied the disappearance of the allergy. The sinister interpretation is that tumours are doing something as they grow that suppresses the immune system and thus allergic reactions. Either way, turnout and lack of allergy coincide. And either way, something interesting is going on. But Dr. Wigertz’s result illustrates the perils of leaping to conclusions on the basis of incomplete data.

选项 A、Nuisance.
B、Pollen.
C、Rash.
D、Shock.

答案C

解析
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