Antibodies for survivors of coronavirus may help current patients

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For 10 seriously ill patients with the new coronavirus, a single dose of antibodies taken from the blood of people who had recovered COVID-19 appeared to save lives, shorten the duration of symptoms, improve oxygen levels and speed up clearance viral, newly published research reports.

The preliminary results came out of a “pilot study” published Monday in PNAS, the Proceedings of the National Academies of Sciences. Carried out in three hospitals in China, he highlighted the promise to collect immune antibodies from recovered people (a therapy also known as convalescent plasma) and administer them to people with severe cases of COVID-19.

But its results offer hope that therapy with a long history and a simple premise could be a powerful treatment for COVID-19 patients who struggle to breathe. Early 20e century, doctors transferred antibodies from the blood of patients who had recovered from polio, measles, mumps and flu to those who still had these infections. Armed with the immune memory of an infected veteran’s virus, patients on convalescent plasma appeared to recover more quickly and completely than patients who had not received treatment, the doctors observed.

With a vaccine in at least a year and no clear treatment available for COVID-19, the U.S. Food and Drug Administration on March 24 approved the use of such therapy as an experimental treatment in clinical trials and for critical patients with no other options.

The new pilot study has indicated that the therapy will not disappoint. A patient, a 46-year-old man with high blood pressure who presented to a hospital with fever, cough, shortness of breath, and chest pain, was using a ventilator to push oxygen into his lungs, and still his blood-oxygen level was a dismal 86%. (Normal readings range from 95% to 100%.)

Eleven days after the first symptoms appeared, the patient received a so-called convalescent plasma infusion. On day 12, her blood was tested negative for SARS-CoV-2 infection. Her body’s inflammation level dropped significantly. And her blood oxygen level had climbed to 90%. The next day, he was weaned from the mechanical ventilation that had breathed him for three days.

In addition to his lungs, the patient’s immune system and liver function, both on the ropes at the height of his illness, returned to normal four days after receiving the infusion of plasma antibodies.

For a 49-year-old woman with no underlying disease, COVID-19 infection quickly progressed to shortness of breath and hospitalization. On the seventh day after the onset of her symptoms, her chest x-ray had shown the characteristic cloudiness of the frosted glass and she had accumulations of fluids or proteins – infiltrates – dispersed in both lungs. On the 10th day after the onset of symptoms, she received a convalescent plasma infusion. By day 12, she had cleared the virus from her system and her chest x-ray was clearly cleaned.

A 50-year-old man with “massive infiltrates” in both lungs showed progressive clearance of his lungs and was found to be negative for the infection 25 days after his first symptoms appeared.

In the ten patients, the symptoms that prompted them to seek emergency care had either disappeared or largely improved within one to three days after receiving a transfusion of antibodies from a recovered donor. Two of the three patients who had breathed using a mechanical ventilator were able to descend to the oxygen delivered by the nose.

None of the 10 patients died and only one unexpected side effect – a red bruise on a patient’s face – was detected.

The study was not designed to have a comparison group of patients who did not obtain convalescent plasma. But the authors created a control group from a random selection of 10 COVID-19 patients treated in the same hospitals and matched to the ten study participants in terms of age, sex and severity of the disease.

The two groups were approximately the same on the first day of their admission to the hospital. But in the weeks that followed, their illnesses progressed in different ways. In the comparison group, three died, six saw their conditions stabilize, and one improved during the study period.

Of those who received convalescent plasma, three were discharged from hospital and the remaining seven were judged to be “well improved” and ready to be discharged.

“This pilot study on [convalescent plasma] the therapy shows a potential therapeutic effect and a low risk in the treatment of severe COVID-19 patients, ”wrote the authors of the new research. “A dose of [convalescent plasma] with a high concentration of neutralizing antibodies can quickly reduce viral load and tend to improve clinical outcomes, “they added.

The authors, chaired by Kai Duan of the National Biotec Group Co. Ltd. from China, said that only larger and more detailed studies would clarify the dose at which convalescent plasma would produce the most healing effects, and when it should ideally be administered.

In recent days, the New York Blood Center (NYBC) has made an urgent appeal to patients recovered from COVID-19 to donate blood plasma for the creation of antibody-rich infusions. The first state blood bank to become a central repository for convalescent plasma, NYBC will collect, process plasma for infusion and maintain a bank for hospitals to treat patients with serious or life-threatening COVID-19 infections.

Operating according to guidelines released last week by the American Assn. of Blood Banks, an international non-profit agency focused on transfusion medicine and cell therapies, dozens of blood transfusion centers across the country have also started collecting blood to create such treatments.

The Mayo Clinic in Rochester, Minnesota has also launched a small trial on convalescent plasma as a way to reduce complications from COVID-19.



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