RESUMO
BackgroundWhether cardiovascular disease (CVD) and its traditional risk factors predict severe coronavirus disease 2019 (COVID-19) is uncertain, in part, because of potential confounding by age and sex. MethodsWe performed a systematic review of studies that explored pre-existing CVD and its traditional risk factors as risk factors of severe COVID-19 (defined as death, acute respiratory distress syndrome, mechanical ventilation, or intensive care unit admission). We searched PubMed and Embase for papers in English with original data ([≥]10 cases of severe COVID-19). Using random-effects models, we pooled relative risk (RR) estimates and conducted meta-regression analyses. ResultsOf the 661 publications identified in our search, 25 papers met our inclusion criteria, with 76,638 COVID-19 patients including 11,766 severe cases. Older age was consistently associated with severe COVID-19 in all eight eligible studies, with RR >[~]5 in >60-65 vs. <50 years. Three studies showed no change in the RR of age after adjusting for covariate(s). In univariate analyses, factors robustly associated with severe COVID-19 were male sex (10 studies; pooled RR=1.73, [95%CI 1.50-2.01]), hypertension (8 studies; 2.87 [2.09-3.93]), diabetes (9 studies; 3.20 [2.26-4.53]), and CVD (10 studies; 4.97 [3.76-6.58]). RR for male sex was likely to be independent of age. For the other three factors, meta-regression analyses suggested confounding by age. Only four studies reported multivariable analysis, but most of them showed adjusted RR [~]2 for hypertension, diabetes, and CVD. No study explored renin-angiotensin system inhibitors as a risk factor for severe COVID-19. ConclusionsDespite the potential for confounding, these results suggest that hypertension, diabetes, and CVD are independently associated with severe COVID-19 and, together with age and male sex, can be used to inform objective decisions on COVID-19 testing, clinical management, and workforce planning.
RESUMO
In previous studies, we demonstrated 10 types of lymphocytes in lymph nodes, each exhibited a different fluorescent color by our thioflavine staining method. Among them, 4 types were able to differentiate into plasma cells of the same fluorescent colors. In the present study, different types of lymphocytes were demonstrated in human peripheral blood by their different fluorescent colors after thioflavine staining. The lymphocytes from the venous blood of 50 healthy persons were isolated with Ficoll-Conray solution and E-rosette and EAC-rosette tests and fluorescent staining with thioflavine were performed. Most of the lymphocytes in peripheral blood are small ones with nuclei and cytoplasm showing blue fluorescence and the blue fluorescence of the cytoplasm is paler than that of the nuclei. The nuclei in a part of these lymphocytes have distinct boundaries. The nuclei in another part of these lymphocytes are smaller and with indistinct boundaries and indentation on one side and show dim fluorescence. Other lymphocytes show different fluorescence. Some show blue round nuclei with distinct nuclear membrane, and no color of fluorescence in cytoplasm, but with blue white patches on one side of the nuclei. Some show dark blue nuclei and bright blue cytoplasm and others show orange yellow or orange red nuclei and yellow cytoplasm. In addition, lymphocytes of grayish blue or grayish yellow nuclei and bluish green cytoplasm or lymphocytes of yellowish fluorescence may be seen at times. Very few lymphoeytes of orange red nuclei with nearly no cytoplasm may be seen occasionally.The lymphocytes with blue fluorescence and indentation on one side of nucleus, those with blue nuclei and blue white patches in the cytoplasm as well as those with orange yellow nuclei and yellow cytoplasm can form E-rosettes with sheep erythrocytes. They are T cells. The lymphocytes with distinct boundaries of nucleus, small size and blue fluorescence those with dark blue nuclei and bright blue cytoplasm as well as those with orange red nuclei and yellow cytoplasm can form EAC-rosettes with sheep erythrocytes sensitized by specific antibody and complement. They are B cells. The lymphocytes with blue nuclei and blue white patches may transform into lymphocytes with orange yellow nuclei and yellow cytoplasm under ultra-violet light irradiation. The latter are few in number in the blood but may be progressively increased in number on prolonged observation. They belong to Group Ⅲ of lymphocytes and are mainly located in the paracortical thymus-dependent zone of lymph nodes. The sma ller lymphocytes with blue fluorescence and distinct nuclear boundary may transform into lymphocytes with orange red nuclei and yellow cytoplasm, which are also very few in number in the blood and are also progressively increased in number on prolonged observation. They belong to Group Ⅱ of lymphocytes and constitute the main component of lymph nodules in lymph nodes.
