Histo-blood group A is a risk factor for severe COVID-19.

OBJECTIVES: Evaluate the impact of ABO histo-blood group type on COVID-19 severity. BACKGROUND: ABO histo-blood type has been associated with different outcomes in infectious diseases. It has also shown a higher proportion of type A patients with SARS-CoV-2. In this observational study, extracted from an ongoing clinical trial on the efficacy of convalescent plasma transfused in COVID-19 patients, we describe the impact of ABO blood type on the risk of developing severe COVID-19. MATERIALS AND METHODS: Seventy-two consecutive patients (37 type A, 23 type O, 11 type B, 1 type AB) with severe (respiratory failure) COVID-19 were included. Control group was composed of 160 individuals randomly selected from the same populational basis. RESULTS: Blood group A was overrepresented (51.39%) in the patient group in relation to the control group (30%), whereas blood group O was less represented (31.94%) in patient than in control group (48%). Odds ratio (A vs. O) was 2.581 (1.381-4.817), CI 95%; p = 0.004. Also, blood group A patients appeared to have more severe disease, given by the scores of the Sequential Organ Failure Assessment and Simplified Acute Physiologic Score 3 (p = 0.036 and p = 0.058, respectively). CONCLUSION: Histo-blood type A is associated with a higher risk of developing severe COVID-19 in relation to blood type O.

Bone marrow-derived dendritic cells under influence of experimental breast cancer and physical activity.

Immune cells are required in the immune response against tumours, although sometimes without success. The present study aimed to investigate dendritic cell (DC) maturation in animals with induced immunosuppression that were subjected to physical activity (PA). Immunosuppression was induced using 7,12-dimethyl-benzanthracene (DMBA). A total of 56 Balb/c mice were divided into four groups, including the control group, non-DMBA administered/PA group (GII), DMBA administered/non-PA group (GIII) and the DMBA administered/PA group (GIV). Bone marrow was removed from the leg bones following sacrifice. Bone marrow-derived DCs were stimulated to differentiate by granulocyte-macrophage colony-stimulating factor, interleukin (IL)-4 and tumour necrosis factor-α, after which the phenotype was assessed by flow cytometry and the cytokine profile was assessed using ELISAs. PA significantly increased the percentage of DCs in GII (55.38±2.63%) and GIV (50.1±3.1%) mice, as compared with GI (34.61±1.28%) and GIII (36.25±1.85%) mice (P<0.05). In addition, GIV mice showed a significantly higher level of cluster of differentiation (CD) 80+/CD86+ DCs (76.38±6.31%), as compared with GI (54.03±6.52%) and GIII (52.07±5.74%) mice (P<0.05). Furthermore, GIV mice showed a significantly higher level of CD80+/major histocompatibility complex class II double labelling (P<0.05), as compared with GIV (95.35±1.22%) and GIII (76.15±5.53%) mice. The expression of interferon-γ was significantly increased in GIV mice [5.89 (5.2-7.12)], as compared with GIII mice [2.75 (1.33-4.4)] (P<0.05). Similarly, the expression of IL-12 was markedly increased in GIV mice [1.27 (0.26-2.57)] compared with GIII mice [0.73 (0.44-1.47)], although the difference was not significant (P=0.063). The results of the present study suggested that PA was able to promote the maturation of DCs and their secretion of anti-tumour cytokines. Therefore, PA may emerge as a tool in immunotherapy.