The article highlights the course of long-term SARS-CoV-2 infection in a patient with a secondary immunodeficiency developed with B-cell-depleting therapy of the underlying disease. Analysis of the intrapatient virus evolution revealed an inpatient S:G75A mutation that alters the 72GTNGTKR78 motif of the S-protein, with a possible role in binding to alternative cellular receptors. Therapy with a ready-made COVID-19-globulin preparation (native human immunoglobulin G (IgG) derived from the plasma of convalescent COVID-19-patients) resulted in rapid improvement of the patient's condition, fast, and stable elimination of the virus, and passive immunization of the patient for at least 30 days. The results suggest the use of products containing neutralizing antibodies opens new prospects for treatment algorithms for patients with persistent coronavirus infection, as well as for passive immunization schemes for patients with a presumably reduced specific response to vaccination.
Keywords: B-cell depletion; COVID-19; Immunodeficiency; Rituximab; SARS-CoV-2; convalescent plasma; coronavirus evolution; human immunoglobulin; normal human intravenous immunoglobulin.