Convalescent Plasma for COVID-19

Kyle Annen, DO, got the call on March 31. A colleague at the UCHealth University of Colorado Hospital, next door to Children’s Hospital Colorado on the Anschutz Medical Campus, had a patient critically ill with COVID-19.

Dr. Annen had thought that call might come. The FDA had approved a somewhat obscure treatment known as convalescent plasma as a treatment for COVID-19 just days before.

The theory, Dr. Annen knew, is that antibodies of a patient recently recovered from infection can continue destroying virus circulating in the blood of a sick patient, granting the sick patient a kind of reprieve to mount their own immune response. It’s never been proven, but there’s evidence of its efficacy dating back to the Spanish flu.

As Medical Director of Transfusion Services at Children’s Colorado’s Blood Donor Center, which collects about 95% of the blood products used within the Children’s Colorado system, Dr. Annen also knew it probably wouldn’t be needed for pediatric patients. But she knew she had some adult donors who’d recovered from the virus, and she’d wondered if their plasma could help patients her colleagues in adult medicine were treating.

So when the call came, she was ready.

A rush to prepare convalescent plasma for release

Dr. Annen immediately got on the phone and found a donor who could come in right away. But she’d still need a negative viral test to prove the donor was no longer contagious. Children’s Colorado already had testing underway, but the donor would still need to come in, get swabbed and wait, masked, for the test to come back before they could donate. The Pathology Lab held the last spot on the last test run of the day.

“I got the call at 11 a.m. and had the product by 9 p.m.,” Dr. Annen recalls. “It was an incredible team effort. I had donor center staff volunteering to stay late, blood bank staff staying late to get it processed, everybody was all in.”

Even then, the product still needed to go through FDA infectious disease testing — the vast majority of which is done out of one processing facility in Texas. Dr. Annen’s team got it on the next flight available. By the time it came back, a day had passed and it was after midnight. Lab supervisor Leanne Polson drove in at 1 a.m. to finish the labeling required to release the product and handed it off to a courier, who ran it across campus to University of Colorado Hospital, where it was immediately infused.

The need for convalescent plasma data

The patient made a gradual recovery, weaning down to minimal vent settings.

Dr. Annen’s team has collected many more units of convalescent plasma since then. For a couple of weeks, they were the only center collecting convalescent plasma in Colorado. Dr. Annen is proud of their responsiveness.

“But we need better data,” she says. “As a treatment, convalescent plasma is relatively low-risk, the same risk as a blood transfusion, but we still don’t have definitive research that it works. I’m hoping to participate in some outcomes studies.

“COVID-19 is terrible,” she adds. “But it’s not going to be the last terrible virus to come through. Proving convalescent plasma works will improve our responsiveness in the future.”