His blood is special and can save the health and even the lives of many fetuses.
James Harrison, an Australian born in 1936, had lobectomy at the age of fourteen and was bleeding profusely during the operation, and doctors gave Harrison thirteen blood transfusions to save him.
After recovering, Harrison was grateful to those who donated blood, believing that their blood had allowed them to survive. In return, he decided to donate blood himself. However, Australian law stipulates that the age of the blood donor must not be less than eighteen years old, so he had to wait patiently and immediately run to donate blood when he reached the age of eighteen.
Not long after, the doctor invited him to the office and told him that his blood was very special and could save the health and even life of many fetuses.
Hemolytic reaction with rare antibodies
In addition to the commonly heard ABO type, there is also a classification that is relatively unfamiliar to the public, that is, Rh type. The difference between these two types is that there are some fine protein structures with special shapes on the surface of red blood cells. Any protein with a special structure may trigger an immune response.
Then from the perspective of clinical operation, it is necessary to consider the blood type matching problem: if it is a rh-negative person, the injected blood is rh-positive, and for his body, those Rh antigens are foreign proteins. The immune system does not like any foreign proteins, and once found, it will attack, and the result of the attack is that the red blood cells are dissolved, which is the hemolytic reaction.
The imported red blood cells carry The Rh antigen and are culled by the Rh-negative immune system as a foreign enemy. Zhu Shisheng painted
Before an adult transfusion, the doctor will check the blood type first, and the blood type match will allow the transfusion, which can avoid hemolytic reactions. The hard thing to do is the fetus. Suppose there is a couple, the man Rh-positive, the woman Rh-negative, after pregnancy, the fetal blood type if with the father, will be Rh-positive, that is, the fetal red blood cell surface has Rh antigen. However, for this mother's immune system, these antigens are foreign proteins that must be attacked.
The response to this attack is lagging behind, and the initial IgM antibody is relatively large and cannot cross the placenta, so the first fetus is less affected by this immune attack, but the mother will leave "memory cells" against this Rh antigen. Later in pregnancies, memory cells allow the immune system to respond quickly, and much smaller IgG antibodies are produced. These antibodies can cross the placenta and can directly attack the red blood cells of the fetus, and the result of the attack is that the fetus undergoes a hemolytic reaction. This can cause stunted fetal brain development and even miscarriage.
The proportion of Rh-negatives in Caucasians is relatively high, accounting for about 15%-18%. In Australia, 17% of pregnant women may develop hemolysis due to this Rh blood group dislocation.
Harrison was asked by the doctor because he had a rare antibody in his blood, which was anti-Rh antibody. If a pregnant woman is found to be Rh-negative and she is pregnant with a fetus that is Rh-positive, as long as such an antibody purification agent is injected once in the twenty-eighth week of pregnancy (when fetal red blood cells begin to have the ability to cross the placenta), the fetal red blood cells that have just leaked into the mother can be immediately removed. After such a cleanup, the mother's own immune system does not have the opportunity to meet the red blood cells of the fetus, and it will not produce corresponding antibodies. This achieves the purpose of protecting the fetus.
The effect of this antibody can last for several weeks, and theoretically, a single injection in the twenty-eighth week of pregnancy can already achieve the goal. It is only during childbirth that the mother's uterine lining is peeled off, and there may be a wound in the birth canal, so there may be contact with umbilical cord blood. The number of fetal red blood cells exposed to this channel is large, and it is more likely to stimulate the immune system and leave memory cells behind. Just in case, another dose is usually added after the fetus is born.
Why Harrison has anti-Rh antibodies in his blood, there is no way to know the exact reason, because according to modern blood transfusion protocols, blood transfusion needs to be matched before. Harrison himself was Rh-negative, and the thirteen bags of blood he was given should have been Rh-negative, but since antibodies appeared in his body, it meant that his immune system had encountered Rh antigens.
The biggest possibility is that in the thirteen bags of blood, one bag of red blood cells carries a trace amount of Rh antigen. I say trace amount because Harrison did not have a significant immune response, such as fever, hemolysis, etc., so that it did not attract attention at that time. Curiously, although it was only a trace antigen, it stimulated a strong and long-lasting reaction in Harrison's body. The concentration of antibodies in his body was particularly high, and this ability to produce high concentrations of antibodies he maintained for a lifetime.
Harrison originally donated blood by drawing whole blood. Knowing that he had this antibody, he consulted the details and knew that whole blood was not needed to extract this antibody, only plasma. The interval between donating whole blood takes three months, while the plasma donation only needs to be spaced two weeks. Since then, he has switched to donating only plasma so that he can donate blood more frequently.
It's not that he enjoys the practice of donating blood. In fact, he was afraid of needles, every time he donated blood, he had to turn his head to the other side, and did not dare to watch the nurse's operation of inserting needles to draw blood, but he still insisted on donating blood once every two to three weeks.
In 2018, he went to the blood bank to donate blood for the last time. It cannot be continued any longer, as the legal age for plasma donation in Australia is capped at eighty-one years. Below is a photo of Harrison's last blood donation. Behind him are several silver floating objects (only the lower half is seen in the photo), which are four balloons specially customized for him by the blood station, which are made into the shape of the four numbers of "1173", representing the number of times he has donated blood in his life.
Insist on donating blood all your life
Save more than two million babies
The antibodies in Harrison's plasma are sent to drug companies and purified into injections. According to Red Cross records, in Australia, more than three million such injections were given to pregnant women, and about two million babies were saved by his plasma.
One doctor speculated that fewer than fifty people across Australia had the antibody in their blood. However, so far, only Harrison has been donating blood all his life.
After the 1960s, the clinical value of anti-Rh antibodies has attracted more and more attention, after several years of exploration and clinical trials, pharmaceutical companies have determined the composition and extraction methods of this antibody, looking for people with this antibody in the body on a global scale, collecting blood, and purifying it into injections. This formulation was approved for use by the U.S. Food and Drug Administration in 1968. Since then, hospitals in various countries can purchase this antibody from pharmaceutical companies. With such a commercial source, Harrison wouldn't have to be busy donating blood if he wanted to, because he could say to himself, "Not one less than me."
But he still donates blood every two or three weeks.
A New York Times reporter asked Harrison what it was like to save two million babies. "It's good to save your baby's life," he said. As for saving two million, that sounds a little scary. If they do come up with such a big number, then of course I'm happy. ”
Drug companies are doing research to try to artificially make this antibody with the help of bioengineering technology. If we succeed, we can get rid of our dependence on human blood, and the Harrisons can breathe some relief in the future.
Harrison was able to donate blood frequently from the age of eighteen to eighty-one because of the body's powerful ability to regenerate blood. On average, the amount of blood accounts for about 10% of the body's body weight, and depending on the weight, a person usually has about 4200-5700 ml of blood. As long as the blood loss of the human body does not exceed 15%, there is usually no special feeling, because the human body has a large surplus of blood.
Normally, about one-sixth of plasma and red blood cells are idle, and only five-sixths are actually engaged in nutrient delivery. Even if blood loss is slightly more than 15%, symptoms do not necessarily occur, because the body's spleen and liver have stored hundreds of milliliters of spare blood. If the amount of blood in the blood vessels is reduced too much, resulting in insufficient blood pressure, the body will automatically react to release the spare blood in the spleen and liver, and still meet the body's oxygen and nutrient needs.
Demand and status quo
According to this physiological mechanism, the upper limit of blood donation in many countries is calculated according to 10% of the blood volume of the human body, and the specific amount varies from place to place, the United States is 500 ml per blood collection, Australia is 470 ml, Canada is 450 ml, and China usually collects 200 ml of blood at a time - if the donor agrees, the blood collection guidelines allow the increase to 400 ml. These blood collections are within the range of the body's redundant blood volume and do not cause blood supply problems in the body. Of course, the premise of the above figures is good health. People who are interested in donating blood should first consult with a doctor to find out whether they have contraindications.
The body reserves one-sixth of its redundant blood volume in order to prevent accidents. If there is a real decrease in blood volume, such as bleeding from a combat injury, or actively donating blood, the body will make adjustments to restore the original redundant reserves. The recovery of plasma volume takes only one to two days. The recovery process of blood cells is slightly slower. The body will increase the rate of blood cell production over a period of time, and within two to three months, the number of blood cells will return to its original level. Whole blood donation requires an interval of three months, that is, to leave enough time for recovery. As for donating plasma, although the liquid content can be restored in less than forty-eight hours, there are some other components in the serum, such as albumin. In order for these ingredients to be fully restored, plasma donations are required to be spaced at intervals of two weeks.
The most important component in the blood is red blood cells. Like many other cells in the human body, erythrocyte lifespan is limited, averaging one hundred and twenty days, and leukocyte lifespan is even shorter, only a few days. That is to say, even if there is no blood loss or blood donation, the blood composition of each of us is constantly renewed, and blood donation can be said to have temporarily accelerated this renewal process for a period of time.
Overall, there is a severe shortage of blood in hospitals worldwide. The American Red Cross has done statistics that in the United States alone, every two seconds there is a patient who needs a blood transfusion, and the amount of blood donated is far from meeting the clinical needs. Blood donation rates vary widely around the world, and according to the World Health Organization, the median proportion of blood donors in the overall population is currently in countries with different income levels:
High-income countries: 3.15%
Upper-middle-income countries: 1.59%
Low- and middle-income countries: 0.68%
Low-income countries:
Most of the blood donation rates in Asian countries are lower than in Europe and the United States, but Taiwan has been performing well in this regard, and the national blood donation rate has remained at 7%-8% for many years. The blood donation rate in the mainland is low all year round, and when encountering relatively rare blood products, such as hematopoietic stem cells, mainland compatriots often need to go to Taiwan to find a matching donor.
Blood donation rates Chinese mainland have been less than 0.5 percent over the past few decades, and according to the World Health Organization, Chinese mainland at the same level as low-income countries. On June 10, 2021, the National Health Commission held a press conference, and Guo Yanhong, inspector of the Medical Administration Bureau, gave a figure, pointing out that the blood donation rate of Chinese mouth was 0.48% in 1998 and increased to 1.1% in 2020, surpassing the level of low- and middle-income countries in the WHO hierarchy. There is room for improvement, but it is indeed a welcome step forward.
When discussing blood donation, many people pointed out that the document on the blood donation policy was far from reality, and the statement that individuals and their families gave priority to blood was almost useless. Such a real problem is frustrating, but students who have the ability to donate blood may be able to continue to donate blood to those who are waiting for help while calling for correction of these deviations, after all, China's current blood bank gap is still huge, and more than half of blood products need to be imported.
Rare blood type "Panda Blood"
Related to this problem is a phenomenon called "panda blood".
The word "panda" is used because this blood type is particularly rare. To determine what blood type is rare, let's first look at the general blood group distribution numbers. We are familiar with ABO blood types, and it should be remembered that the distribution of several blood types in the population is not even, but the racial differences are not too large. The following figure comes from the Australian Academy of Sciences article on blood types, the red numbers in the figure are the australian population blood group distribution, of which A, B, AB and O are more familiar, the plus and minus signs after these letters indicate Rh positive or negative, such as "A-" means A blood type, Rh negative, and "O+" means O type blood, Rh positive.
The red percentage is a number for Australia. Yellow is the proportion of AB rh negatives in China.
In this table, most of the numbers vary little from country to country, and the more special is the "AB-" in the first line, that is, AB plus Rh negative.
As mentioned earlier, Caucasians have Rh-negative 15%-18%, but this proportion is very low in the Asian and African population, especially in China, where only 0.4% of the total population is low.
Because rh-negative in the Chinese mouth accounts for less than 1%, it is not easy to mismatch between the blood type of pregnant women and fetuses. But that's not to say it's completely impossible. The maternal physical examination includes Rh blood group test, but because there are too few negative cases, it is rare to encounter a doctor saying to the mother, "You are Rh negative, you need to give you antibodies" this kind of thing.
Ab type is also relatively rare, but it is still higher than Rh negative, accounting for about 7% of the population in China.
Ab type and Rh negative are rare, then both AB type and Rh negative, of course, are even less. It's like there are fewer people with red hair and fewer people who can shake their ears, so there are red haired people who can shake their ears at the same time, naturally there are very few, belonging to the rare category of panda level. For this reason, rh-negative Chinese accounts for 0.4% of the total population, while AB-type Rh-negative accounts for only 0.03% of the population, that is, about three out of 10,000 people. In the chart above, the woman in the first row represents the "1%" share, which is the distribution of "AB-" in the Australian population. According to this ratio projection, the AB type of the Chinese mouth plus Rh negative, the proportion is roughly equivalent to the small yellow dot on the woman's left hand. This can be regarded as a graphic expression of the word "panda blood".
Chinese Rh negative is rare, and the good thing is that Chinese women who give birth to children rarely need to worry about fetal hemolysis because of this problem. The bad side is that if someone is AB plus Rh-negative, that is, the so-called panda blood, then in case there is a need for blood transfusion, it is likely that the whole city will not find a blood type match, a physique suitable for blood donation, and people who are willing to donate blood. If this is the case for you, it is recommended to pay attention to homogeneous blood mutual aid organizations, through which you can find suitable blood donors more quickly if necessary.
Source: Read Library
Author: Zhu Shisheng
Editor-in-charge: Tian Dongliang
Proofreader: Zang Hengjia
Plate making: Xue Jiao