What Is the Role of Therapeutic Plasma Exchange as an Adjunctive Treatment in Severe COVID-19: A Systematic Review

Introduction: Since the COVID-19 pandemic outbreak, multiple promising treatment modalities have been tested, however, only several of them were proven to be effective. Therapeutic plasma exchange (TPE) has been recently discussed as a possible supportive treatment for severe cases. Methods: To investigate a possible role of TPE in severe COVID-19 we used a structured systematic search strategy to retrieve all relevant publications in the field. We screened in PubMed, EMBASE, Web of Science, Cochrane Library and clinicaltrials.gov for data published until the 4 June 2021. Results: We identified 18 papers, enrolling 384 patients, 220 of whom received TPE. The number of TPE sessions ranged from 1 to 9 and the type of replacement fluid varied markedly between studies (fresh frozen plasma or 5% albumin solution, or convalescent plasma). Biochemical improvement was observed in majority of studies as far as C-reactive protein (CRP), interleukin-6 (IL-6), ferritin, lactate dehydrogenase (LDH), D-dimer concentrations and lymphocyte count are concerned. The improvement at a laboratory level was associated with enhancement of respiratory function. Adverse effects were limited to five episodes of transient hypotension and one femoral artery puncture and thrombophlebitis. Conclusions: Although the effect of therapeutic plasma exchange on mortality remains unclarified, the procedure seems to improve various secondary end-points such as PaO(2)/FiO(2) ratio or biomarkers of inflammation. Therapeutic plasma exchange appears to be a safe treatment modality in COVID-19 patients in terms of side effects.