Patients with pre-existing comorbidities and immunosuppression are at greater risk for
SARS-CoV-2 infection and severe manifestations of COVID-19. This also includes cancer
patients, who are shown to have a poor prognosis after infection. Here, we describe the
case of a 72-year old male patient with B-cell depletion after maintenance treatment
with rituximab for non-Hodgkin-lymphoma who had a prolonged COVID-19 course and
initial false negative test results. Our case highlights the diagnostic pitfalls in diagnosing
COVID-19 in B-cell depleted patients and discuss the role of B-cell depletion in the course
and treatment of COVID-19. Furthermore, we investigated peripheral blood monocytes
and SARS-CoV-2 specific T cells in our patient. In conclusion, our case report can help
physicians to avoid diagnostic pitfalls for COVID-19 in hemato-oncological patients under
chemoimmunotherapy and tries to explain the role of B-cell depletion and SARS-CoV-2
specific T cells in this context
