Study on leukapheresis of hyperleukocytic acute myeloid leukemia through in vitro centrifugation.

Respiratory failure, intracranial hemorrhage and infection were more common in hyperleukocytic acute myeloid leukemia patients than in non-hyperleukocytic leukemia patients. Compared with non-apheresis treatment, the white blood cells decreased significantly and the infection rate decreased after apheresis treatment. However, the treatment time of leukapheresis in patients with hyperleukocytic leukemia is very long, while it is more damaging to cells. In this study, which conducted a retrospective analysis on patients with hyperleukocytic acute myeloid leukemia, the process of centrifugation of normal cells and patients' cells by apheresis machine was simulated in vitro. Through selecting 5 healthy persons and 11 patients with hyperleukocytic acute myeloid leukemia, extracting their blood samples and performing in vitro centrifugation at different speeds or duration, we observed the changes of the numbers and morphology of peripheral blood cells in healthy people and patients, so as to explore the optimal centrifugation parameters during leukapheresis. The cells obtained by the optimal centrifugation parameters were cryopreserved and two groups of mice (10 mice in each group) were used to establish leukemia animal models. Through the research, it is found that when the centrifugal speed is below 6000 rpm, the damage to blood cells in healthy people and in patients with hyperleukocytic leukemia is not obvious. When the centrifugal speed is above 6000 rpm, the platelets will be damaged significantly. The cells obtained under the optimal centrifugation parameters can be successfully cryopreserved and used to establish leukemia animal models. This study is of great significance for improving the efficiency and reducing the side effects of leukapheresis, and is helpful to improve the treatment of white blood cells reduction.

Safety and efficiency of stem cell therapy for COVID-19: a systematic review and meta-analysis.

BACKGROUND: With the COVID-19 pandemic continuing, various treatments have become widely practiced. Stem cells have a wide range of applications in the treatment of lung diseases and have therefore been experimentally used to treat patients with COVID-19, but whether the expanded use of stem cells is safe and reliable still lacks enough evidence. To address this issue, we systematically reviewed the safety and efficiency of stem cell therapy in COVID-19 cases. METHODS: We searched PubMed, Embase, Web of Science, The Cochrane Library, CNKI, WanFang, VIP and SinoMed up to January 18, 2022. The included studies were assessed using the Risk-of-bias tool 1.0 and MINORS instrument. The adverse events, mortality, length of hospital day and laboratory parameters were analyzed by meta-analysis. We adhered to PRISMA reporting guideline. RESULTS: We have included 17 studies meeting the inclusion data. There were no significant differences in AEs (OR = 0·39, 95% CI = 0·12 to 1·33, P = 0·13, I2 = 58%) and SAEs (OR = 0·21, 95% CI = 0·04 to 1·03, P = 0·05, I2 = 0%) between stem cell therapy group and control group. The analysis showed that stem cell treatment could significantly reduce the mortality rate(OR = 0·24, 95% CI = 0·13 to 0·45, P < 0·01, I2 = 0%), but was not able to cause changes in length of hospital stay or most laboratory parameters. CONCLUSIONS: The present study shows that stem cell therapy for COVID-19 has a remarkable effect on efficiency without increasing risks of adverse events and length of hospital stay. It is potentially necessary to establish the criteria for COVID-19 for stem cell therapy.