The kidney transplant process is a tightrope walk between rejection and infection.
Writing |Wan Shunshun
Source | “Medical Community” Public Account
On August 31, in Mr. Lei, 27, a healthy kidney, from a father with a different blood type, began filtering blood.
It is reported that this is the first cross-blood type kidney transplant successfully performed by Xiangya Hospital of Central South University.
“The risk of rejection and infection in cross-blood type kidney transplantation is higher than that of living-donor kidney transplantation from relatives of the same blood type, but it is better than the cadaveric kidney donated after the death of a citizen.” Associate Professor Ding Xiang of the Transplant Center told ” Medicine”.
September 21, a group photo of the patient being discharged from the hospital (the 1st from the left is Associate Professor Ding Xiang) / Photo courtesy of the interviewee
Uremia at a young age
The kidneys are the silent and hardworking workers in the human body, processing an average of 1.2 liters of blood per minute. Chronic kidney disease often has an insidious onset, with mild initial symptoms that are difficult to detect, and most patients are diagnosed at a later stage.
When working in Guangdong last year, Mr. Lei felt tired, had unexplained bleeding gums, and had a systolic blood pressure of 190mmHg. This series of symptoms found the answer in the Department of Nephrology, Xiangya Hospital, Central South University – end-stage renal failure, commonly known as uremia.
The effect of regular hemodialysis for a year on Mr. Lei was not good. First of all, hemodialysis two or three times a week greatly affected the patient’s ability to work. Second, some patients with kidney disease cannot tolerate hemodialysis. After each dialysis, Mr. Lei felt numbness in his hands and feet, fatigue and fatigue.
Kidney transplantation became his optimal solution, even the final solution.
In May of this year, Associate Professor Ding Xiang treated Mr. Lei’s family in the outpatient clinic of the Transplant Center of Xiangya Hospital, Central South University. In order to save his young son, the father is willing to donate a kidney. “All tests are qualified, except for the blood type. Mr. Lei has blood type B, and his father is type AB, which does not conform to the normal ABO blood transfusion principle.”
“We fully communicate with patients’ families about the options for cross-blood kidney transplantation, other options are continued dialysis treatment, and registration in the National Organ Allocation Waiting System (CORTS) for kidneys awaiting the death of a citizen Ding Xiang said that there are many patients waiting for a suitable kidney source. Generally speaking, most patients need to wait for more than one or two years.
Ding Xiang came up with a set of detailed data: in December 2020, there were about 59,000 people waiting for kidney transplants nationwide, and about 10,000 kidney transplants can be completed in my country every year. many people. Hunan is the hardest hit area for chronic kidney disease. The incidence of chronic kidney disease and the rate of dialysis in the province rank high in the country.
The development of ABOi blood group incompatible relative donor kidney transplantation (ABOi-KT, commonly known as cross-blood type kidney transplantation) technology can effectively solve the problem of shortage of transplanted kidneys.
According to the “Technical Operational Specification for Living Donor Kidney Transplantation for ABO Blood Group Incompatible Relatives (2019 Edition)”, ABOi-KT has been routinely carried out in Japan, Europe and the United States and other countries. Compared with ABO blood group compatible kidney transplantation, there is no difference, or even better.
In 2006, China’s first cross-blood type kidney transplant was performed in Hunan. The Kidney Transplant Center of the Second Affiliated Hospital of South China University in Hunan performed a kidney transplant for a patient with type O blood, whose father was the donor.
Although it is the first case of cross-blood kidney transplantation in Xiangya Hospital. Since 2018, Ding Xiang has performed kidney transplants for more than 20 uremic patients with hypersensitivity to HLA. Currently, the survival rate of transplanted kidneys and patients is 100%.
“Technically there is not much difficulty, because we have a lot of successful experience, this is just replacing the donor-specific antibody against the HLA site with a blood type antibody.” Ding Xiang said.
Arrived at the operating room at 8:30, Ding Xiang and his team removed the patient’s father’s kidney under minimally invasive laparoscopy. After 11:00, the kidney extraction operation was completed. After a brief rest, they performed surgery on the donor and recipient. Around 13:00, the kidneys implanted in the patient reopened blood flow, and at 14:00, the operation was basically over.
Walking a tightrope between rejection and infection
The entire kidney transplant process is like walking a tightrope between rejection and infection, and both must be taken care of.
Ding Xiang said that the first thing that cross-blood kidney transplantation faces is rejection: first, intraoperative hyperacute rejection, which directly leads to the loss of function of the transplanted kidney; second, about 2 weeks after the operation, Acute rejection is often caused by increased blood group antibody rebound.
The first step, how to avoid acute rejection caused by blood group antibodies?
In conjunction with the blood transfusion department, laboratory department, nephrology department and other related departments, Ding Xiang used plasma exchange to reduce the natural blood type antibody in Mr. Lei’s body according to the patient’s blood type antibody.
Ding Xiang organizes case discussions and formulates surgical plans/Photo provided by the interviewee
According to the requirements of the “Code of Practice for Living Donor Kidney Transplantation for ABO Blood Group Incompatible Relatives (2019 Edition)”, for anti-A-IgG, IgM and anti-B-IgG, IgM antibody titers, On the day of transplantation in adult patients, anti-A-IgM≤1:16, IgG≤1:16 should be controlled; anti-B-IgM≤1:16, IgG≤1:16.
Before the operation, Mr. Lei repeated plasma exchange three times to reduce the blood group antibody titer from 1:32 just after admission to below 1:8.
The second step, how to prevent the continued production of antibodies and rebound?
Ding Xiang introduced that after the initial cross-blood type transplantation, splenectomy was required, which was very harmful to the body of patients with uremia. Now, we use CD20 monoclonal antibody drug to eliminate B cells expressing CD20 molecule. This drug doesn’t kill 100% of all B cells in the body, it just helps patients get through the most dangerous time. “
Subsequently, it is necessary to rely on the transplanted kidney and the body to establish immune tolerance. After the most dangerous period of the first two weeks, even if the blood group antibody titer increases again, it will not cause obvious rejection damage.
Infection prevention and control after living donor kidney transplantation is a long-term task.
“If you suppress your immunity so that the transplanted kidney does not reject, the risk of infection will increase significantly. Because the human body actually coexists with bacteria and viruses, we There are many bacteria and viruses in the body. Cytomegalovirus, BK virus, and EB virus have an infection rate of 80% in the population. In the case of low immunity, it is a big problem.”
Some studies have pointed out that lung infection is the most common infection in patients undergoing living donor kidney transplantation, and the incidence of pneumonia is 5-20 times higher than that of normal people, which is the most common postoperative Common serious complications.
Ding Xiang is trying to find a balance and minimize risks. “For cytomegalovirus, patients with the same blood type should be prevented with drugs for 3-6 months, and patients with different blood types should be prevented for more than 6 months; for Pneumocystis fungal infection, the general transplant patients should be prevented with medication for 6 months to one year, and patients with different blood types should be prevented with drugs for 6 months to one year. For patients with different blood types, we would recommend medication for more than one year.”
Can it solve the shortage of kidney transplant donors?
According to the China Kidney Disease Network, the incidence of chronic kidney disease in China is as high as 10.8%, and the number of patients exceeds 130 million, of which nearly 2.8 million end-stage patients require renal replacement therapy. Many uremia patients die while waiting for a kidney transplant.
Since there is a path of living donor kidney transplantation with relatives, why are so many uremic patients waiting in line for surgery?
Ding Xiang explained that the first thing to do is to ensure the health of kidney donors. He often encounters relatives who are willing to donate, but because of high blood pressure, diabetes, or kidney function can not meet the requirements. I estimate that at least 1/3-1/2 of the relatives may not meet the requirements. “This is the case of the same blood type. It is possible that after cross-blood type transplantation, the chances of obtaining a kidney transplant for the patient will be significantly increased.”
Cross-type living donor kidney transplantation also has specific donor health requirements. The “Clinical Diagnosis and Treatment Guidelines for Living Donor Kidney Transplantation in ABO Blood Group Incompatible Relatives” pointed out that there are 9 absolute contraindications and 13 relative contraindications for ABOi-KT relative living donor surgery.
Absolute contraindications include: (1) extensive metastases or uncured tumors; (2) severe mental illness and intractable psychological and social problems; (3) irreversible organ function (4) Serious neurological damage such as irreversible brain damage; (5) Drug abusers; (6) Acute active hepatitis; (7) Endogenous creatinine clearance <70mL/min; (8) Body mass index >35 kg/m2; (9) age <18 years old.
Crossing the blood group barrier can also be a challenge for doctors. “We must not only ensure the safety of the recipient’s kidney transplant operation, but also ensure the health of the donor after donating a kidney. Although ABOi-KT can alleviate the source of healthy organs, I think it should be carried out cautiously.”< /p>
In terms of overall treatment costs, Ding Xiang said that a cross-blood type kidney transplant will cost about 50,000 to 100,000 yuan more than a same-blood type kidney transplant. If the whole process goes smoothly, the cost is not very high. Once severe rejection or infection occurs, the difficulty and cost of treatment will skyrocket.
As a clinician, Ding Xiang feels that the incidence of uremia among young people is on the rise in recent years.
He believes that this is the result of a combination of social environment, natural environment and innate factors. In terms of social environment, young people have a lot of work pressure, often stay up late, eat late-night snacks, which increases the burden on the kidneys, resulting in hypertensive nephropathy and diabetic nephropathy. In the natural environment, there is clear evidence that air pollution (especially PM2.5) is associated with the incidence of kidney disease.
Ding Xiang suggested that young people should pay attention to kidney health, regular physical examinations, and at the same time pay attention to prevention, improve their living habits, and prevent related diseases such as high blood pressure and diabetes.
 Organ Transplantation Branch of Chinese Medical Association. Technical Operational Specification for Living Donor Kidney Transplantation for ABO Blood Group Incompatible Relatives (2019 Edition) [J]. Organ Transplantation, 2019, 10(5) :533-539.doi:10.3969/j.issn.1674-7445.2019.05.012
 Wang Yi. Guidelines for Clinical Diagnosis and Treatment of Living Donor Kidney Transplantation for ABO Blood Group Incompatible Relatives (2017 Edition) [J/CD]. Chinese Journal of Transplantation (Electronic Edition), 2017,11( 4):193-200.DOI:10.3877/cma.j.issn.1674-3903.2017.04.001.
Proofreading: Zang Hengjia
Editor in charge: Wang Xiao
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