Background: The diminished immune response observed in individuals with rheumatic diseases is a contributing factor to the occurrence of tuberculosis (TB) infection. The primary objectives of this investigation were to examine the risk factors associated with the advancement of rheumatic diseases in conjunction with latent tuberculosis infection (LTBI) leading to active tuberculosis (ATB). Methods: A retrospective study was conducted at the Xijing Hospital of the Fourth Military Medical University, utilizing the Laboratory Information System (LIS), to investigate rheumatic diseases diagnosed between January 2012 and October 2022. The collected data underwent statistical analysis using the Social Science Statistical Package (SPSS) version 26, with a significance level of p < 0.05 indicating statistical significance. Results: The research conducted involved a total of 33,020 individuals diagnosed with rheumatic conditions, of which only 18.16% underwent screening for latent tuberculosis infection (LTBI). Among the rheumatic patients, the incidence of LTBI was found to be 25.33%, with 14.57% of these cases progressing to active tuberculosis (ATB). Utilizing binary logistic regression analysis, it was determined that exposure to glucocorticoids (GCs) at a dosage of 20 mg/d or higher was an independent risk factor for the development of ATB [odds ratios (OR) = 3.59, 95% CI: 1.26-10.29, p = 0.017]. Conclusion: It is of the utmost importance to perform a screening for LTBI prior to commencing treatment in patients with rheumatic conditions, as they are at a significantly elevated risk of developing ATB due to their exposure to medium-high doses of glucocorticoids (GCs). Keywords: Latent tuberculosis infection; Active tuberculosis; Rheumatic diseases; Risk factors

Background: The unreliability of reference intervals (RIs) for children’s blood cell analysis has led to an unnecessary effort in interpreting results. The Standard published in 2021 is expected to solve this problem in China but should be clinically evaluated before its application. Methods: Compared with the laboratory’s original RIs, the RIs’ numerical trends were mapped and analyzed, and the data of the past seven years were retrospectively re-interpreted. Pediatricians were then consulted to discuss the data analyses. Results: The new RIs were summarized as follows: 1) The age stratification is more detailed; 2) The venous blood and peripheral blood are characterized; 3) The numerical range was relatively more comprehensive, and some parameters were unilaterally shifted. Retrospective analysis showed that the revised RIs could correct previously abnormal results to the normal range in a large proportion. The recovery ratio of three lineage cells was white blood cells > red blood cells > platelets, and the ratio sorted by age is 28 days~1-year-old > 1~13years old > 13~18 years old. The leukocyte recovery ratio of 28 days~1 year was the largest, approximately 55% to 83%. Pediatricians recognized the value of the new RIs. The only exception is that the platelets’ RIs were too broad, recommending maintaining the original RI. The missing 0~28 days RIs were recommended to be supplemented with other reference books. Conclusions: The new RIs were optimized and, combined with clinical feedback, produced new RIs derived from accumulated experience, evolving a better set of RIs.