Convalescent plasma, cytomegalovirus infection, and persistent leukopenia in COVID-19 recovery phase: What is the link?

Therapies used to tide over acute crisis of COVID-19 infection may lower the immunity, which can lead to secondary infection or a reactivation of latent infection. We report a 75-years-old male patient who had suffered from severe COVID-19 infection three weeks earlier and who had been treated with corticosteroids and convalescent plasma along with other supportive therapies. At time of discharge he had developed leukopenia which worsened at 1-week follow up visit. On 18(th) day post-discharge, he became very sick and was brought to our hospital with complaints of severe persistent dysphagia. During evaluation he was diagnosed to have an acute cytomegalovirus infection and severe oropharyngeal thrush. Both COVID-19 and cytomegalovirus are known to cause synergistic decrease in T cells and NK cells leading to immunosuppression. The patient made complete recovery with a course of intravenous ganciclovir and fluconazole. Persistent leukopenia in high risk and severely ill cases should give rise to a suspicion of COVID-19 and cytomegalovirus co-infection.