The association between ABO blood-group system and congenital microtia

Abstract

Objective To investigate the association between ABO blood-group system and congenital microtia. Methods Patients with congenital microtia treated in the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences from January 1, 2017 to February 28, 2019 were collected as the case group. Non-malformed patients admitted to the same hospital from January 1, 2017 to February 28, 2019 were collected as the control group. ABO blood group was determined by tube agglutination test. The distribution of ABO blood group in both group was counted and Chi-square test was used for statistical analysis with a significance level α=0.05. Then spilt chi-square test was applied to compare the difference between blood groups using Bonferroni correction for multiple comparisons (significance level α′=0.008 3) if a statistically significant difference was found in chi-square test. Odds ratio (OR) and its 95% confidence intervals (CI) were calculated to compare the association between ABO blood group and risk of microtia by using Woolf’s method . All statistical analysis was performed with SPSS version 25.0. Results 2 317 patients with congenital microtia (case group) and 5 411 patients without malformation (control group) were included in this study. The distribution of ABO blood types in congenital microtia group was 29.39% (681/2 317) for type A, 31.89% (739/2 317) for type B, 9.75% (226/2 317) for type AB, and 28.97% (671/2 317) for type O. The distribution of blood group was B>A>O>AB. While, the distribution of blood groups in the control group was O>B>A>AB, which was statistically different from the congenital microtia group (χ2=8.387, P=0.039). The incidence of congenital microtia differed significantly between A blood group and O blood group (χ2=7.448, P=0.006). The risk of congenital microtia was significantly lower in blood group O (OR=0.863, 95% CI: 0.776-0.960, P=0.007) and relatively higher in blood group A (OR=1.110, 95% CI: 0.997-1.236). Conclusions In the population managed in the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences, ABO blood group is correlated with the occurrence of congenital microtia. O blood group is a potential protective factor. While A blood group is susceptible to congenital microtia. Key words: ABO blood-group system; Congenital microtia; Odds ratio