hey guys so a lot of you've been asking about convalescent plasma the fda recently issued
an emergency authorization for doctors to treat covid 19 using convalescent plasma from patients
who've recovered from the disease but researchers and doctors are concerned that this push to
distribute convolution plasma could undermine the clinical trials needed to determine whether it
actually works against this coronavirus in other words people with covid 19 might choose to access
the treatment directly rather than sign up for a clinical trial and therefore risk being assigned
to a control group that receives placebo instead of actual treatment now in order to understand
the science behind what is going on with and plasma we first have to understand what it is
and how it works then i'm going to talk about my experience giving it to coronavirus patients
and what the studies are actually showing so let's get to it so what is convalescent plasma or cpt
when someone is infected with covid 19 and they recover they then develop antibodies
typically within a few weeks how long these antibodies last and how effective they are
against the virus is a whole other conversation but these igm and igg antibodies are in the
bloodstream when someone is recovered from the covid 19 infection or actively going through it
so when a patient who is recovered from covid that blood then gets spun well it gets drawn first into
a tube and then it gets spun in a centrifuge and then collected a certain portion of that
blood is called plasma and in that plasma are the immunoglobulins including igg and igm antibodies
the rest of the blood mainly red blood cells and platelets is used for blood transfusions
so with the plasma that we collect that's what contains the antibodies to the virus
and then we give that to hospitalized covid patients they did this for some patients with
the first sars virus and for mers and they had good results then in 2019 i'm sorry
2009 there's an observational study of over 90 critically ill patients who had h1n1 influenza a
20 of those patients received convalescent plasma the ones who received the plasma did have better
survival rates but that's a very small sample size now in theory the covid patients who would most
likely benefit from cpt would be the ones who get the plasma as soon as they're diagnosed with it
in the hospital setting the sooner they get it the higher the likelihood of it being effective
at least in theory also the higher the number of antibodies in that plasma the more likely it is to
be effective at least in theory although some us hospitals have already been given plasma for covid 19
in special cases an emergency use authorization from the fda would make it easier to give it to
more and more patients so my hospital is part of a clinical trial for cpt and we've been giving it
to covid patients now based on my experience it's hard to know if it makes any difference at all i
can tell you that there's been not one patient who i've given it to and then all of a sudden
they're magically better within a day or two or even three days so i haven't really noticed much
of a difference i've given it to many patients and they've been good outcomes and bad outcomes
and everything in between for the patients who did improve was this because of the cpt was it
because of the dexamethasone they received or the rem deserver that they received or the tosylisimab
that they received or was it just a coincidence and they're going to get better regardless
or is it some sort of combination of these things it's impossible to know
the only real way to know if any of these treatments make any kind of difference
is to have randomized controlled trials that involves lots of patients
so far there have been no randomized controlled trials for cpt when it comes to covid now based
on the published observational studies we have so far there's little evidence to suggest that cpt
actually helps patients with covid in the hospital now convalescent plasma has been tested only in
small trials without the statistical power to provide firm conclusions another consideration
is that convolution plasma from different people varies widely in antibody concentration
meaning different amounts of antibodies so one person might receive less antibodies compared
to someone else and on top of that we don't even know how effective these antibodies are
meaning are these antibodies considered to be neutralizing antibodies now the biomedical
advanced research and development authority or barda in the u.s has provided convalescent plasma
on this basis to more than 70 000 people but this was done without having any control groups meaning
there were any randomized controlled trials the fda chief dr stephen hahn recently said in a tweet
that cpt is associated with a 35 percent improvement in survival this is absolutely wrong
he later corrected himself saying the data so far show a relative risk reduction not an
absolute risk reduction but this statement is still not accurate why now i'm not going to get
into the biostatistics here but the bottom line is you can't talk about relative risk
reduction in absolute risk reduction unless it's a randomized controlled trial and there is no
randomized controlled trial that's been completed yet with respect to covid and cpt now i'll put a
link in the description below to a good website that explains the basics of biostatistics as it
pertains to relative risk reduction and absolute risk reduction but dr han is referring to this
study which was done at mayo clinic where they transfused over 35 000 covet patients with cpt
it's an observational study not a randomized control trial these 35 000 covid patients they
didn't all have the same degree of illness some of them were hospitalized but not but did not require
icu some of them required icu but not require a breathing tube with mechanical ventilation
also the patients had different patient characteristics meaning some were young some were
old some had more risk factors than others such as obesity diabetes and high blood pressure and such
also some received dexamethasone and or rem deserver so there's so many variables at play here
and that's a big reason why it's so hard to get concrete results from these studies
and that's why it's all the more necessary to have randomized control trials but with
all those things being said let's take a look at this observational study of 35 000 patients
the 7-day mortality rate meaning the percentage of patients who died within a week of being diagnosed
was 8.7 in patients transfused within three days of covid 19 diagnosis the 7-day mortality rate
was 11.9 in patients transfused four or more days after diagnosis what was the mortality rate
of people who were given placebo we don't know because this wasn't a randomized control trial so
all this is telling me so far is that the number is slightly better not much better slightly better
in the group who got the plasma sooner they also looked at 30-day mortality rate which was 21.6 and
those who got plasma sooner versus 26.7 percent and those who got plasma later for patients who
received plasma that contained high amounts of igg antibodies the seven day mortality was 8.9
compared with those who received low amounts of igg plasma levels that mortality rate was 13.7
percent so this study suggests that both earlier time to transfusion and higher antibody levels
help to slightly reduce mortality keyword being there suggests so if you want to prove it you have
to do a randomized control trial and calculate the real risk reduction but the fda cited data
from this non-peer-reviewed observational study and claimed there's a 35 mortality reduction
it's just flat out wrong that's not what this study is saying at all that's just bad science
the good news is that overall cpt is very safe and side effects are rare the two most
common side effects that can occur are transfusion associated circulatory overload or taco for short
as well as transfusion related acute lung injury or trolley taco occurs when the body cannot handle
a sudden large volume of blood transfusion in which the body becomes volume overloaded typical
symptoms include shortness of breath as a result of fluid that builds up in the lungs trolley is
an immune reaction that occurs when antibodies from the donor's blood meaning the donor's plasma
has a reaction toward the recipient's body the most common scenario in this context is when
antibodies against human leukocyte antigens or hla develop in women who've had multiple pregnancies
this is the reason why the fda advised against women who've been pregnant before
from donating convalescent plasma for the covid 19. trolley just like taco typically causes
shortness of breath other potential complications of cpt include transfusion allergic reactions so
this can be in the form of rashes and anaphylactic reactions but again all of these potential adverse
effects are rare in a published study of 5 000 hospitalized covert patients who received cpt
there were 36 serious adverse events so 11 of those were trolleys seven of those were tacos
and there's also three reports of severe allergic transfusion reactions so the rate of serious
adverse offense is actually less than one percent and the overall takeaway from this video is that
this recent announcement about cpt being a major advancement in the treatment of covet patients is
nonsense we need randomized controlled trials to know if it truly helps hospitalized covet patients
based on the observational studies we have so far and based on my personal experience
this isn't some game-changer therapy the randomized control trial may
end up showing that it helps with covid similar to what dexamethasone does
but unfortunately i seriously doubt it'll be anything more than that