Convalescent Plasma Therapy Procedure
Overview
Convalescent plasma therapy uses plasma from people who have recovered from a specific illness. This plasma contains antibodies, which are proteins the immune system creates to help fight off viruses.
After recovery, healthcare workers collect blood from donors and separate plasma from other blood cells. The remaining plasma, rich in antibodies, may help someone else’s immune system respond to the same illness.
Key Points:
- Utilizes antibodies from people who have recovered from illness.
- Offers a form of passive immunity.
- Applied in cases like pandemic influenza, Ebola, and Lassa virus.
Table: Historical Uses of Convalescent Blood Products
| Disease | Usage Period | Outcome |
|---|---|---|
| Spanish influenza pandemic | Early 20th century | Reduced mortality |
| Pandemic influenza (H1N1) | 2009 | Improved survival |
| Ebola, Lassa virus outbreaks | 21st century | Supportive treatment |
Historic figures like Emil von Behring contributed to antibody therapy and serum therapy research, helping guide modern passive antibody therapies. Today, healthcare providers continue to use convalescent plasma as a supportive treatment option, especially for individuals with weak immune systems.
Reasons for Using Convalescent Plasma Therapy
Healthcare providers use convalescent plasma therapy as a supportive treatment for different infectious diseases, especially when other options are limited or unavailable. This approach involves collecting blood plasma from people who have recovered from illnesses such as COVID-19, severe acute respiratory syndrome (SARS-CoV-1), and Middle East respiratory syndrome (MERS-CoV). The donated plasma contains antibodies, which may help fight infections in patients whose immune systems are not able to respond quickly or strongly enough.
Key Reasons for This Therapy
No Available Vaccine or Medicine: When new viruses, like SARS-CoV-2, first appear, vaccines and specific treatments are often not yet available. Convalescent plasma becomes an option to help affected patients.
Weakened Immune System: People with weakened immune systems or lymphocytopenia may have trouble producing antibodies after infections from pathogens such as coronavirus, measles, mumps, or H1N1 influenza virus.
Reducing Severe Complications: The therapy can help lower the risk of serious issues like pneumonia or inflammation in patients with infections including COVID-19, meningococcal meningitis, chickenpox, and Argentine hemorrhagic fever.
The World Health Organization and regulatory agencies have considered emergency use authorization for convalescent plasma during outbreaks. Patients who are vaccinated and then contract viral infections provide plasma rich in antibodies, potentially offering increased protection, especially for those without other treatment options.
Common Diseases Treated with Convalescent Plasma
| Disease/Condition | Reason for Use |
|---|---|
| COVID-19 | Lower risk of severe illness, support recovery |
| SARS-CoV-1 / MERS / MERS-CoV | Alternative when medications are limited |
| H1N1 Influenza | Treatment during outbreaks |
| Measles, Mumps, Chickenpox | Support for severe or high-risk cases |
| Meningococcal Meningitis | When immediate antibody help is needed |
Possible Dangers
Convalescent plasma therapy can cause side effects, just like other blood transfusions. Common risks include allergic reactions, fever, and mild skin rashes. Rarely, more serious issues may happen. These can include lung injury, trouble breathing, or transfusion reactions.
There is also a very small chance of getting infections such as HIV or hepatitis B and C, though blood screening helps prevent this. Immunocompromised patients need extra caution. Safety depends on blood type compatibility and other health factors.
Key Points Table
| Risk Type | Details |
|---|---|
| Allergic Reactions | Mild to severe |
| Lung Complications | Trouble breathing, lung injury |
| Infection Risk | Very low, but possible |
| Transfusion Reactions | Can be serious |
| Effect on CRP Levels | Monitored in some cases |
What You Can Expect
A healthcare provider prepares the patient by placing a sterile, single-use needle into a vein, usually in the arm. This needle connects to an IV line, which allows fluids or medications to enter the bloodstream. The area is cleaned to reduce the risk of infection, and the patient rests quietly during the setup.
Steps Before the Procedure
| Step | Description |
|---|---|
| Blood match | The care team checks that the donor plasma matches the patient’s blood type. |
| Equipment | All equipment used is sterile and single-use for safety. |
| Preparation | Patients may have vital signs checked and may need to stop certain medications. |
What Happens During Plasma Infusion
Once compatible convalescent plasma arrives, staff connect it to the IV line. The plasma, which is rich in antibodies like IgG, IgA, and IgM, is slowly transfused into the patient’s body to support their immune system. Healthcare workers observe the patient closely for signs of any transfusion reaction, especially in the first 15 minutes after starting the plasma. Key points during the infusion:
- The process usually takes 1 to 2 hours.
- Staff monitor the patient for side effects.
- The transfused plasma helps the body fight infection, especially when used alongside antiviral drugs.
What Happens After Plasma Infusion
After the transfusion, the patient may remain at the hospital for a short observation. If not admitted, they are usually allowed to leave soon after. The care team reviews the patient’s response to treatment and checks for any delayed reactions or side effects.
Sometimes, the care team may give an additional unit of COVID-19 convalescent plasma or other antiviral treatments such as lopinavir-ritonavir to aid recovery. If any unusual symptoms appear, the patient should contact their healthcare provider right away.
Findings
Clinical trials and observational studies suggest that convalescent plasma, especially when it has high levels of neutralizing antibodies, can have positive effects in some patients. Patients with weaker immune systems sometimes show faster recovery or shorter illness duration after receiving high-titer plasma. Key observations based on studies and reports:
- Some clinical studies show improved viral clearance and reduced risk of severe outcomes.
- Researchers continue to analyze data from randomized controlled trials and case reports.
- Systematic reviews highlight modest clinical efficacy, mostly in cases with early treatment.
| Study Type | Outcome |
|---|---|
| Clinical Trials | Mixed effectiveness |
| Observational Studies | Some positive effects |
| Case Reports | Faster recovery possible |
Scientists continue to examine the overall safety and benefit of this therapy in various groups.
