Patients who had more severe COVID-19 may be the best donors for
convalescent plasma therapy
Study links stronger antibody responses to more severe disease, as well
as more advanced age and male sex

Date:
October 19, 2020
Source:
Johns Hopkins University Bloomberg School of Public Health
Summary:
Sex, age, and severity of disease may be useful in identifying
COVID-19 survivors who are likely to have high levels of antibodies
that can protect against the disease.



FULL STORY ==========================================================================
Sex, age, and severity of disease may be useful in identifying
COVID-19 survivors who are likely to have high levels of antibodies
that can protect against the disease, according to a new study co-led
by researchers at Johns Hopkins Bloomberg School of Public Health.


==========================================================================
The findings suggest that older males who have recovered from COVID-19
after having been hospitalized are strong candidates for donating plasma
for treating COVID-19 patients. Doctors have been using infusions of
plasma -- the part of blood that contains antibodies -- from recovered
COVID-19 patients to treat COVID-19 patients and also as a possible
prophylaxis to prevent COVID-19.

Doctors have used convalescent plasma to treat patients or immunize
persons at high risk of virus exposure during outbreaks of measles,
mumps, polio, Ebola, and even the 1918 pandemic flu.

Clinical trials of convalescent plasma treatment against COVID-19 are
ongoing, and doctors until now haven't had guidance for selecting COVID-19 survivors who are likeliest to have strong antibody responses.

"We propose that sex, age, and severity of disease should be used to
guide the selection of donors for convalescent plasma transfer studies
because we found that these were significant patient characteristics
that not only predicted the amount of antibody but the quality of that antibody," says study lead author Sabra Klein, PhD, professor in the
Bloomberg School's Department of Molecular Microbiology and Immunology.

The study, published October 19 in the Journal of Clinical Investigation,
was a collaboration with several other research groups including that
of Arturo Casadevall, MD, PhD, Bloomberg Distinguished Professor and
chair of the Department of Molecular Microbiology and Immunology, and co-corresponding author Aaron Tobian, MD, PhD, professor in the Department
of Pathology and director of the Transfusion Medicine Division at the
Johns Hopkins School of Medicine.



==========================================================================
For their study, the researchers tested the blood of 126 COVID-19
survivors and found high variability in their antibody levels and their antibodies' ability to neutralize the COVID-19-causing coronavirus,
SARS-CoV-2. Three factors were associated with stronger antibody
responses: having been sick enough with COVID-19 to be hospitalized,
being older, and being male.

Initial studies of recovered COVID-19 patients have revealed a significant variability in their antibody responses to the virus -- some survivors
having very weak responses that would almost certainly be ineffective in helping new patients. The researchers in the new study looked for factors
that might help explain some of that variability and guide clinicians to
the patients most likely to have high levels of SARS-CoV-2 neutralizing antibodies.

The researchers examined samples of plasma from the 126 recovered patients using several tests. These included tests of the plasma's ability in cell cultures to neutralize cell-to-cell infection with SARS-CoV-2, as well
as commercial tests for levels of antibodies to the coronavirus's spike
protein - - the protein that studs the surface of coronavirus particles
and allows the virus to attach to and infiltrate human cells.

Consistent with several prior studies, the researchers found considerable variability among the subjects in their spike-protein antibody levels and plasma coronavirus-neutralization potency. But on average, the plasma
of survivors who had been hospitalized with COVID-19 had markedly more anti-spike protein antibodies and neutralized the virus more effectively
-- suggesting that disease severity prompts a stronger immune response.

"We know that the magnitude of antibody responses correlates with disease severity in other infectious diseases, such as active tuberculosis,"
Klein says.

Older age and male sex, which prior studies in both China and Europe have
shown are associated with more severe COVID-19, were also associated
with stronger antibody responses, though these links were weaker than
for hospitalization status.

As part of their study, the researchers also tested study participants
with commercial test kits and found that recovered COVID-19 patients who
have strong neutralizing antibody responses also are very likely to have
high levels of coronavirus anti-spike antibodies. This suggests that this
type of test kit, which is relatively inexpensive, might be a good tool
for identifying suitable plasma donors for clinical trials and treatments.

"Sex, age, and hospitalization drive antibody responses in a COVID-19 convalescent plasma donor population," was funded by the National
Institutes of Health (U54AG062333, HHSN272201400007C, T32A1007417,
AI052733, AI15207, R01AI120938, R01AI120938S1, R01AI128779,
1K23HL151826-01, R01HL059842), Bloomberg Philanthropies, and the
Department of Defense (W911QY2090012).


========================================================================== Story Source: Materials provided by Johns_Hopkins_University_Bloomberg_School_of_Public Health. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Sabra L. Klein, Andrew Pekosz, Han-Sol Park, Rebecca L. Ursin,
Janna R.

Shapiro, Sarah E. Benner, Kirsten Littlefield, Swetha Kumar,
Harnish Mukesh Naik, Michael J. Betenbaugh, Ruchee Shrestha, Annie
A. Wu, Robert M. Hughes, Imani Burgess, Patricio Caturegli, Oliver
Laeyendecker, Thomas C. Quinn, David Sullivan, Shmuel Shoham, Andrew
D. Redd, Evan M. Bloch, Arturo Casadevall, Aaron A.R. Tobian. Sex,
age, and hospitalization drive antibody responses in a COVID-19
convalescent plasma donor population.

Journal of Clinical Investigation, 2020; DOI: 10.1172/JCI142004 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201019164942.htm

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