Objective To analyze the causal relationship between educational attainment and the risk of systemic lupus erythematosus (SLE). Methods Based on the data from publicly available genome-wide association studies, we employed single nucleotide polymorphisms (SNPs) strongly associated with educational attainment as instrumental variables. Two-sample Mendelian randomization analysis was used to investigate the causal relationship between educational attainment and SLE. The primary analysis method used was the inverse variance weighted with multiplicative random effects. Validation methods included inverse variance weighted with fixed effects and MR-Egger methods. Additionally, sensitivity analysis was conducted using the leave-one-out approach. Results Finally, 433 SNPs were included. The inverse variance weighted with multiplicative random effects analysis indicated no causal effect of educational attainment on the risk of SLE [odds ratio =1.111, 95% confidence interval (0.813, 1.518), P=0.509]. Similarly, the other two methods did not find any evidence of a causal relationship (P>0.05); however, significant heterogeneity was observed. The MR-Egger regression analysis provided no evidence of horizontal pleiotropy among the included instrumental variables (P>0.05). The leave-one-out approach did not identify any individual SNP that had a significant impact on the overall effect estimate. ConclusionIn conclusion, this study does not support a causal effect of educational attainment on the risk of SLE.
Objective To explore the factors influencing 2-month sputum smear conversion (2m-SSC) in patients with systemic lupus erythematosus (SLE) and tuberculosis, and to establish a prediction model for 2m-SSC. Methods The initial and follow-up medical records of inpatients with SLE and sputum smear-positive tuberculosis in West China Hospital of Sichuan University from December 2013 to September 2019 were retrospectively reviewed. Single factor analyses and multivariable Firth’s logistic regression were used to determine the influencing factors of 2m-SSC, and a prediction model for 2m-SSC was established. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated to evaluate the performance of the model. Results A total of 91 patients with SLE and sputum smear-positive tuberculosis were ultimately included, with 8 cases in the non-conversion group and 83 in the conversion group. There were statistically significant differences in white blood cell count, total bilirubin, indirect bilirubin (IBIL), triglyceride, and rheumatoid factor (RF) between the two groups (P<0.05). Serum RF [odds ratio (OR)=2.271, 95% confidence interval (CI) (1.312, 4.350), P=0.003], IBIL [OR=2.363, 95%CI (1.206, 5.045), P=0.013], and glucose [OR=2.058, 95%CI (1.016, 4.280), P=0.045] were identified as risk factors unfavorable to 2m-SSC outcomes. The constructed model (including three variables: RF, IBIL, and glucose) had a good ability in predicting 2m-SSC [AUC=0.893, 95%CI (0.744, 1.000)], with a sensitivity of 87.5% and a specificity of 84.3%. Conclusion This study established a prediction model for 2m-SSC in patients with SLE and tuberculosis, and found the value of serum RF, IBIL, and glucose in predicting 2m-SSC, providing certain guidance for clinicians in treatment decisions.