Haematological malignancy patients infected with COVID-19 appear to achieve improved clinical outcomes after receiving convalescent plasma therapy
Haematological malignancy patients infected with COVID-19 can expect better clinical outcomes after receipt of convalescent plasma according to the results of a pre-print systematic review by researchers from the Department of Biomedical Science, Qatar University, Doha, Qatar.
Patients with any form of cancer have been deemed particularly vulnerable to infection with COVID‐19 given how immunodeficiency is a secondary consequence of their cancer treatment. Convalescent plasma (CP) therapy is a type of passive immunity whereby plasma enriched with specific antibodies generated by patients who have recovered from a specific infection, is transfused into other patients.
The possible value of CP in those with cancers such as a haematological malignancy, the the authors of one study conclude that convalescent plasma may be a promising therapy in cancer patients with COVID-19. Despite these potentially promising results, the use of convalescent plasma therapy among patients with cancer, especially those with a haematological malignancy has not been systematically reviewed.
For the present study, the Qatarian team focused on haematological malignancies and searched for studies that included patients infected with COVID-19, based on a PCR confirmed result and who were treated with convalescent plasma. Included studies were those reported in English and either randomised trials or prospective and retrospective comparative cohort studies.
The authors extracted malignancy data and set several primary outcome measure of clinical improvement including mortality, viral clearance and recovery one month post-treatment. The main secondary outcome was adverse events after use of convalescent therapy.
Haematological malignancy outcomes and convalescent plasma
A total of 17 studies with 1103 patients of whom 258 had one or more haematological malignancies were included in the analysis. Among these studies, 13 were case reports or case series, two were retrospective in nature and two were observational studies.
The main haematological malignancies were follicular lymphoma, chronic lymphocytic leukaemia, non-Hodgkin’s lymphoma, diffused large B-cell lymphoma and B-cell lymphoma.
The dose of convalescent plasma ranged from 200 – 300 ml per transfusion and in many cases this therapy was used as the last option.
Mortality was the main clinical outcome reported in 21.7% of patients receiving CP and 25.2% in control patients. The use of CP was associated with an improved overall survival (odds ratio, OR = 1.41, 95% CI 0.99 – 1.99), viral clearance (OR = 2, 95% CI 1.04 – 2.08), detection of COVID-19 antibodies in the recipient’s plasma (OR = 6.33) and recovery one month after the use of CP (OR = 1.74, 95% CI 1.1 – 2.8).
The probability of developing an adverse effect in haematological malignancy patients was significantly reduced in those given CP compared to controls (OR = 0.24, 95% CI 0.14 – 0.40).
The authors concluded that CP was an effective and safe treatment for patients with haematological malignancies infected with COVID-19, adding that there was a need for further studies to provide a better understanding of the value of this intervention in cancer patients.
Shibeeb S et al. Effectiveness of convalescent plasma therapy in COVID-19 patients with haematological malignancies MedRxiv 2022