COVID-19 and Blood Type

• Blood type and outcomes in patients with COVID-19. 7/12/2020. Latz C. Ann Hematol.
  Retrospective study of 1289 SARS-CoV-2 + patients /7648 tested patients w/ known ABO blood type. No blood group had an increased or decreased risk of severe disease, inflammatory markers, intubation, or death.  Type A had the expected risk of +PCR, type A, type O had a lower risk and types B and AB and Rh+ patients had a higher risk.  These results contrast w/ previous reports, however data are not fully comparable.
• ABO Phenotype and Death in Critically Ill Patients with COVID-19. 7/1/20. Leaf RK. Br J Haematol.
  In this Letter to the Editor, ABO blood type data from adults admitted to ICUs over 38 days in the 67-center Study of the Treatment and Outcomes in critically ill Patients from COVID-19 (STOP-COVID) study were analyzed. Patients were followed until hospital discharge, death, or May 8, 2020 – a date that included a minimum of 28 days follow-up for those still hospitalized. 2033/3239 (62.8%) had ABO data available. 799/2033 (39.3%) died within 28 days. Death rates were similar across ABO phenotypes in all race/ethnicity categories, as well as Rh status. Among White patients, the observed distribution of ABO phenotypes differed from expected, primarily due to blood type A being over-represented (45.1% observed vs. 39.8% expected) and blood type O being under-represented (37.8% observed versus 45.2% expected). Among Black and Hispanic patients the observed and expected distributions of ABO phenotypes were similar.
• Genomewide association study of severe covid-19 with respiratory failure. 6/17/2020. Ellinghaus D. N Engl J Med.
  Genetic differences may in part explain the difference in response of different persons to SARS-CoV-2. They compared hospitalized patients with respiratory failure with controls. They studied 835 patients and 1255 controls from Italy and 775 patients and 950 controls from Spain.
  They found 3p21.31 gene cluster is a genetic susceptibility locus. Patients with blood group A were found to be at a higher risk of infection (odds ratio, 1.45) and develop more severe symptoms. Patients with blood type O were found to be at a lower risk of infection (odds ratio, 0.65). Although the results are statistically significant, the effect size is small.
• Relationship between ABO blood group distribution and clinical characteristics in patients with COVID-19. 6/21/20. Wu Y. Clin Chim Acta.
  Retrospective case controlled study of Wuhan patients admitted to a single Chinese hospital 1/20/20 – 3/5/20. 187 study patients were admitted with COVID-19 while 1991 control patients were COVID negative individuals admitted during the same time period. The proportion of patients with type A blood in the COVID-19 group was significantly higher than that in the control group (36.90% vs. 27.47%, P = 0.006), while the proportion of patients with type O blood in the COVID-19 group was significantly lower than that in the control group (21.92% vs. 30.19%, P = 0.018). Blood group A patients had a higher risk of COVID-19 than non-A blood group patients. (OR = 1.544, 95% CI = 1.122–2.104, P = 0.006). Blood group O patients had a lower risk of COVID-19 than non-O blood group patients (OR = 0.649, 95% CI = 0.457–0.927, P = 0.018).
• Association between ABO blood groups and risk of SARS-CoV-2 pneumonia. May 7. Li. Br J Haematol.
  In this brief study report of 265 COVID-19 patients from Wuhan, China, “The ABO blood group … showed a distribution of 39.3 %, 25.3 %, 9.8 % and 25.7 % for A, B, AB and O, respectively. The proportion of blood group A in patients infected with SARS-CoV-2 was significantly higher than that in healthy controls (39.3 % versus 32.3 %, P= 0.017), while the proportion of blood group O in patients infected with SARS-CoV-2 was significantly lower than that in healthy controls (25.7 % versus 33.8 %, P< 0.01).” The theory that adhesion of SARS-CoV-2 to ACE-2 receptor is inhibited by human natural anti-A antibodies is discussed.
• ABO blood group predisposes to COVID-19 severity and cardiovascular diseases. Apr 29. Dai. Eur J Prev Cardiol.
  The authors state “Although ABO blood type and/or cardiovascular diseases are prognostic of COVID-19 patient severity, they are not risk factors predisposing to the risk of getting SARS-CoV-2 infection”. However, their report is of a proposed theory that relative differences in ACE and ACE2 receptor activity in persons with differing ABO blood types results in higher Covid-19 severity in A-type individuals, with no data or citations to back up the idea.