Ask Dr. H: Is DNA passed from a blood donor
Question: I've been taking Nexium for several years to treat Barrett's esophagus. I have heard that long-term use of acid-blocking drugs like Nexium can increase the risk of pneumonia. Why would it cause that? How much of a risk is it for me?
Q: Since our DNA can be detected from our blood, do we also pick up a blood donor's DNA when we receive a blood transfusion?
A: The short answer is no. When we receive blood, we are not usually receiving a blood donor's whole blood; rather, only the red blood cells. The DNA resides in a cell's nucleus, and since mature red blood cells don't have a nucleus they don't have any DNA material.
Whole blood contains not only red blood cells, but also other components like serum, white blood cells, platelets, and antibodies. It is the white blood cell component of whole blood that contains the nuclei and therein one's genetic material in the form of DNA.
However, even if one received a whole-blood transfusion rather than the red blood cells alone, the DNA profile of a donor would not be detected in the peripheral blood of a recipient.
In one study, a woman in a trauma situation was transfused with 14 units of blood (four of those units being whole blood) without showing any detectable level of foreign DNA. In another study, a man in a trauma situation received 13 units of blood (four of those units being whole blood) without showing any detectable level of the donor's DNA. That's a lot of blood they received, considering that the average woman has 8 to 10 pints/units of whole blood and the average man has 10 to 12 pints/units of blood.
Question: I've been taking Nexium for several years to treat Barrett's esophagus. I have heard that long-term use of acid-blocking drugs like Nexium can increase the risk of pneumonia. Why would it cause that? How much of a risk is it for me?
Answer: The timing of your question is superb, because a recent retrospective study conducted by researchers at the Massachusetts General Hospital Department of Medicine poked huge holes in the conclusion of previous studies linking chronic use of proton pump inhibitors (PPIs) like Nexium and Prilosec to a roughly 1 percent per-year increased risk of developing pneumonia.
The widely held belief has been that suppressing stomach acid can allow the growth of ingested bacteria to increase the risk of pneumonia. The belief is so strong that the FDA has issued warnings over it.
To disprove this association, Anupam Jena and his colleagues at Massachusetts General used the strategy of "falsification." They analyzed 11 years of insurance claims from 54,500 adults, both PPI users and non-PPI users, as to whether they had received diagnosis or treatment for health problems like osteoarthritis, chest pain, urinary tract infections, and skin infections - conditions that would be expected to have no increased risk from PPI use.
The results showed that folks taking PPIs like Nexium were more likely than non-PPI users to have osteoarthritis, chest pain, and urinary tract infections, along with pneumonia. They were also more likely to be diagnosed or treated for conditions including cancer, diabetes, or stroke - conditions that have nothing to do with use of PPI drugs like Nexium.
Based on their analysis published online in the Journal of General Internal Medicine, it appears Nexium will not increase your risk of pneumonia.