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Comment by chrisco255 | Hacker News Reader

I've followed it closely but the death toll outside of China is really low. Some reports are that this disease binds to specific receptors in the lungs that are especially prominent in Asian males:

"The result indicates that the ACE2 virus receptor expression is concentrated in a small population of type II alveolar cells (AT2). Surprisingly, we found that this population of ACE2-expressing AT2 also highly expressed many other genes that positively regulating viral reproduction and transmission. A comparison between eight individual samples demonstrated that the Asian male one has an extremely large number of ACE2-expressing cells in the lung."

Which is disturbing all the same, but it means the fatality rate will be lower among non-Asians, unless the disease mutates further, which is very possible.

https://www.biorxiv.org/content/10.1101/2020.01.26.919985v1

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It's worth reading the paper, which calls out its own limitations:

* It is unknown if ACE2 is the only important receptor * Study doesn't actually count the amount of ACE2 receptors, just the amount of RNA expression (ok, you can probably hand wave this limitation away) * Study also shows a difference of expression ratio of 1.6% vs 0.4% in males vs females (n=2 vs n=6) * There was a SINGLE asian male in the data set

Given these limitations of the original paper, at the very least, I would say that you should shy away from definitive statements until stronger evidence appears.

The top comment on biorxiv ran with some of the ideas from the paper, and looked at a more general and larger data set and found no statistically significant difference between Asian and Caucasian lung tissue samples in terms of ACE2 expression when measured in bulk (see https://uploads.disquscdn.com/images/5cb4b2c5e1ae3cf8454e870...)

That said, it's certainly a cool paper.

> (n=2 vs n=6) * There was a SINGLE asian male in the data set

From my understanding of statistics and biology this is not significant at all then.

From that link above, "there are eight and 436 putative Asians and Caucasians, respectively (imputed from the first two principal components" so its comparing a sample size of 8 Asians with a sample size of 436 Caucasians. I'd say the jury is still out on whether there is a racial difference in ACE2 expression, but good call out either way.

I remember reading something about how something like half of chinese men smoke and that was potentially what was leading to their susceptibility to pneumonia from ncov. would be happy if someone could source that.

This 2015 article published in Lancet says 2/3 of Chinese men smoke and 3% of women. https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

Here are two excerpts I am basing my summary on:

Two-thirds of the men smoked; there was little dependence of male smoking prevalence on age, but many smokers had not smoked cigarettes throughout adult life. Comparing men born before and since 1950, in the older generation, the age at which smoking had started was later and, particularly in rural areas, lifelong exclusive cigarette use was less common than in the younger generation.

Women were included only in the second study. Of 302 669 women enrolled in 2004–08, only 3·2% were ever regular smokers, including 0·5% who stopped by choice. Smoking uptake decreased steeply across successive generations of women.

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