Authors (including presenting author) :
Chan KLL(1), Chan HYK(1), Lau WNG(1), Ho WBL(1), Kwok CHK(1), Ho SKS(1), Lee KKH(1), Tsang TYO (2), Mak WMV(1)
Affiliation :
(1) Division of Haematology and Haematological Oncology, Department of Medicine and Geriatrics, Princess Margaret Hospital
(2) Hospital Authority Infectious Disease Centre
Introduction :
The reported inpatient morality rate of COVID-19 patients with haematological malignancy was as high as 30% because of their impaired immunity. We aimed at studying the clinical outcomes of this high-risk group during a major outbreak in Hong Kong in early 2022.
Objectives :
To study the rate of hospitalisation, serious infection and death owing to COVID-19 infection in patients with haematological malignancy, and identify the predictors of these adverse outcome events.
Methodology :
This is a retrospective study using data from the COVID-19 registry set up by the haematology unit of Princess Margaret Hospital to facilitate clinical management. Patients infected with COVID-19 between 6 Feb to 1 Apr 2022 were included. Multi-variable regression analysis was performed to identify the predictors of adverse outcomes.
Result & Outcome :
The study included 124 patients (male – 57%, mean age 64.7+/-12.2 years) with different haematological malignancies: acute leukaemia (15%), lymphoma (36%), plasma cell myeloma (42%) and others (7%). At the time of infection, 107 patients (86%) were undergoing cancer therapy. Fifty-six patients (45%) received two or more doses of COVID-19 vaccines [BioNTech 43%; CoronaVac 57%], 26 patients (21%) received one dose and 42 (34%) were unvaccinated.
Overall, 43 patients (35%) were admitted for management of COVID-19 infection. Sixteen patients (12%) developed serious infection (requiring oxygen supplement >3L/min). Elderly (>65 years) (P=0.005 & 0.03 respectively) and unvaccinated patients (P=0.04 & 0.03 respectively) were at higher risk of hospitalisation and serious infection. The number of COVID-19 related deaths was 13 (10%). Higher mortality risk was again observed in the elderly (odd ratio [OR] 25.7, 95%CI: 3.2-inf, P=0.02) and unvaccinated patients (OR 3.6, 95%CI: 1.1-14.1, P=0.04). The category of haematological malignancy, type of vaccine, concurrent cancer treatment and neutropenia were not associated with adverse outcomes.
Anti-SARS-CoV-2 RBD antibodies were positive in 69 (70%) out of 99 convalescent patients who had testing performed from day 14 to 180 post-infection. The positive rate was lower in patients who received anti-CD20 antibody as cancer treatment (OR 0.26, 95%CI 0.09-0.72, P=0.04).
To conclude, vaccination might protect patients with haematological malignancy against poor outcomes of COVID-19 infection. It is concerning that certain patients did not develop antibody after recovery. Real-world data is warranted to study the role of pre-exposure antibody prophylaxis and antivirals in this vulnerable group of patients.
