Clinical use of convalescent plasma (CP) for COVID-19
While there are few studies to guide the use of CP for SARS-CoV-2 infection (COVID-19 disease), recent studies have shown that the neutralizing antibodies in the CP result in disappearing viremia and improvements in oxygen saturation. Due to these encouraging results and the successful use of CP in other respiratory diseases, we posit there are four general classes of potential recipients:
- Those with critical disease, 5% of infected symptomatic individuals, who have multiorgan failure and COVID-related acute respiratory distress syndrome (ARDS). While the pathophysiology of this stage is not clear, it may be due to cytokines as a result of a direct viricidal effect and subsequent release of inflammatory markers.
- Those with severe disease, 14% of infected symptomatic individuals, who have dyspnea, hypoxia or >50% lung involvement on imaging.
- Those who have tested positive, 81% of infected symptomatic individuals, but have mild to moderate symptoms.
- Those who are high-risk for infection post-exposure and for having serious illness (such as being older or immunocompromised) as prophylactic measure.
The current Mayo Clinic expanded access protocol allows for treatment of patients with COVID-19 who are severe, critical, or at high risk of progressing to severe or critical disease, as defined below. NYBC is working with our partners at Columbia and Hopkins in randomized control trials investigating the use of CP as prophylaxis and in individuals with no, mild, or moderate symptoms. Another clinical trial will investigate its use in pediatric patients. As no US trials have been completed, it is unknown if CP will be of differential value in these groups, but it might be hypothesized that in groups 2-4 above the Ig fraction of the CP might dampen viral load while the recipient’s immune system is ramping up to deal with the infection and prevent critical illness.
At present, the Mayo Clinic Expanded Access Program allows for the following (complete information at uscovidplasma.org):
Hospitalized patients are eligible to receive convalescent plasma if:
- They are 18+ years of age
- They have laboratory-confirmed diagnosis of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19
- They are admitted to an acute care facility for the treatment of COVID-19 complications
- They have severe or life-threatening COVID-19, or judged by the treating provider to be at high risk of progression to severe or life-threatening disease
- There is informed consent provided by the patient or healthcare proxy
Severe COVID-19 is defined by one or more of the following:
- Shortness of breath (dyspnea)
- Respiratory frequency ≥ 30/min
- Blood oxygen saturation ≤ 93%
- Partial pressure of arterial oxygen to fraction of inspired oxygen ratio < 300
- Lung infiltrates > 50% within 24 to 48 hours
Life-threatening COVID-19 is defined as one or more of the following:
- Respiratory failure
- Septic shock
- Multiple organ dysfunction or failure
The FDA Single Patient Emergency IND is currently only for patients with serious or life-threatening COVID-19 disease.