"Convalescent Plasma" Treatment Is Not That Simple: Expert Tips To Promote Application Difficulties.

Convalescent plasma therapy has become a hot topic, and many blood products companies have taken the lead.

On the evening of February 13th, at the news conference of the new type of coronavirus pneumonia epidemic prevention and control in Hubei Province, Zhang Dingyu, director of the hospital of Wuhan golden Yin Tan, said that the hospital was carrying out the plasma transfusion of the convalescent patients during the convalescence stage, and has shown the initial effect. He urged the patients after recovery to "come to the hospital actively, extend their arms, donate plasma, and jointly rescue patients who are still struggling with the disease."

In February 13th, China Bio group, a subsidiary of China Pharmaceutical Group, announced that high potency virus neutralizing antibodies have been detected in plasma of the new crown pneumonia rehabilitation patients, and the experiments proved that the new crown virus could be effectively killed. Chinese biology says, "we treat 11 critically ill patients with the special plasma of rehabilitative patients. The curative effect is remarkable." Affected by this news, related blood products stocks rose collectively. Among them, Wei Guang biology, Tiantan biology and Bo Hui's innovation limit; Shanghai leas rose more than 8%.

Shanghai Institute of Pasteur, Chinese Academy of Sciences explains that blood consists mainly of blood cells and plasma, and plasma is the serum after removing fibrinogen. Serum therapy was used by scientists to fight infectious diseases caused by bacteria more than 100 years ago, but the feasibility depends on the actual situation.

Huang Bo, deputy director of the Chinese society of immunology and executive deputy director of Immunology Department of Beijing Union Medical College, stressed the need to recognize the pros and cons of serum antibodies. "We need to have enough knowledge of the complexities of antibodies and even the aggravation of diseases."

It has been a long time but it is not easy to popularize.

Tong Zhaohui, Beijing Chaoyang Hospital's vice president and respiratory critical expert, wrote in February 13th that the so-called plasma treatment during convalescence refers to a passive immunotherapy method after collecting blood from patients with convalescent period rich in antibodies and giving them special treatment and infusion to other patients. Antibody is a protective protein produced by the stimulation of an antigen (such as a virus). After the virus is cleared, the body still has a high level of antibody in the short term, and it decreases with time. In the treatment of new crown pneumonia, we can use the convalescent plasma therapy empirically, but its extensive promotion still needs further clinical trials.

Ding Sheng, the first Dean of the school of pharmacy at Tsinghua University, said that in theory, if there are enough effective antibodies in patients with convalescent stage, their plasma will be transmitted to the infected person. If the infected person is in the pathogenic stage of the virus, the antibody may neutralize the virus and play a role in relieving the disease.

Plasma can play a certain role in convalescence, but there are many difficulties in specific utility, blood collection and promotion.

"At present, only a few patients with critical illness can be tried," said Deng Yu, director of the Department of critical care medicine of Guangdong General Hospital. "At present, only a few patients with critical illness can make some attempts. Because a large amount of demand is needed, a critically ill patient may need 7-10 blood donors to provide plasma for the rehabilitation of the blood group, and it will be more difficult to push it up in."

"Chinese biological group has not disclosed the number of antibodies detected by various rehabilitative patients, and there is no controlled test. In fact, the effect of antibody can not be completely conclusive. If there is a method of measuring antibody titer, it can explain the problem. In addition, each person, at different times, the antibodies are different. Plasma should be tested to exclude hepatitis A, HCV, AIDS, syphilis and other pathogens. Then centrifugation and neutralization antibodies can be used for patients. Critically ill patients need antibodies, and they also need to deal with inflammatory storms caused by viral infections. It was only given this plasma that inhibited the virus itself, but it did not inhibit the inflammatory storm. " Department of Hematology, a third class hospital in Guangzhou, told reporters on twenty-first Century economic report.

Besides, the way of plasma life saving is not easy. Looking back at the history of human viral resistance, convalescent plasma therapy is no mystery. This is a long history of treatment, which can be traced back to 1891. This year, in the pediatric ward of the Berlin University Affiliated clinic, German doctor Emil Behring injected a serum to a dying diphtheria child, which contained Diphtheria Antitoxin. On the second day, the patient's condition improved markedly. Antibody therapy for diphtheria has become an important milestone in the history of medicine.

In the struggle against SARS in 2003, after countless studies and clinical practice of numerous scholars, China has concluded a set of clinical experience in the treatment of SARS with convalescent plasma. Since then, in the epidemic of MERS, influenza A, Ebola virus and so on, researchers at home and abroad have made use of convalescent plasma therapy to achieve certain results in disease treatment.

But Professor Jiang Suchun, a No.302 Hospital of the PLA who is engaged in communicable disease control, has said that the use of serum antibodies produced by SARS rehabilitative people can help to kill SARS virus in critically ill patients.

This is often the last straw to help when there is nothing to do. It is precisely because it is the last straw that has some drawbacks. The serum obtained from the rehabilitative body can be used as a temporary means to help one or two people get rid of the acute phase of the virus. But the lack of sufficient sources of blood is the reality we need to face.

In addition to the challenge of "quantity", there are challenges in the standardized operation process, effectiveness and exclusion of plasma therapy during convalescence. The antibody levels in different patients vary greatly, and standardized management of plasma manipulation is not as simple.

On the other hand, after the discharge of the cured, there is an antibody in the blood, but there is still a risk of reinfection, indicating that the time and dose effect of the antibody in the body will decrease in a short time, so that the follow-up may not guarantee the cure of the virus itself, and whether the virus will mutate in other patients is also unknown.

In addition, after the serum of the healer is injected, the patient will have more or less immune rejection. Other concurrent problems caused by blood transfusion are the risks that must be considered.

Blood products sector led A shares

On the other side of the capital market, the blood products sector is rapidly "red". At present, there are 11 blood products concept stocks in A shares, of which 8 opened up more than 5% in the morning. As of February 14th, 10 stocks rose and only 1 fell. Wei Guang biology, Tiantan biology, Bo Hui innovation and other trading, Shanghai leas and Boya biology rose more than 5%.

China Bio holding's only listed company, Tiantan biology, continued to float in the blood products sector. From February 4th to February 13th, Tiantan's biological growth rose by more than 20%. Under the leadership of Tiantan bio, the blood products concept stocks rose.

However, for the performance of blood products concept stocks, Lin Cun, chairman of Shenzhen sunray Cci Capital Ltd, analyzed that the blood products concept stocks had performed well in the past few years, and the internal logic came from the demand for Human Immunoglobulin for Intravenous Injection, which is still in the epidemic. "There is no specific medicine at present. Static C plays an important role in enhancing immunity. The new crown pneumonia epidemic has changed the supply and demand of the market, and has also promoted the price of static C." However, Lin stressed that the plasma treatment during convalescence is strictly related to the blood products company.

The reporter asked the relevant person in charge of the bio Securities Department of Tiantan to inquire about the R & D progress and clinical situation, indicating that it is still in the process of understanding and verifying the situation. For the research and development of special plasma products, Hua Lan said that the relevant projects are being developed, but the specific progress is not yet clear. Shanghai Lloyd's said that at present the main product of conventional product development. Boya Bio said that at present, the sampling area is limited and the number of samples is small. The follow-up will be promoted according to the sampling and experimental results.

The number of domestic blood products enterprises is large. In 2019, there were 15 Records issued by batch. At present, the demand for blood products is large, the supply is relatively tight, and the contradiction between supply and demand is outstanding. The premise of blood products volume is sufficient supply of plasma and smooth pulp production. However, affected by the epidemic, the National Pulp station has basically stopped working and the raw materials are very tight.