ABSTRACT
Objective To explore the diagnostic values of combined detection of serum procalcitonin (PCT) and β2 microglobulin (β2MG) in tsutsugamushi disease.Methods Serum PCT and β2MG were compared in cases of tsutsugamushi disease and fever patients at the same time,who were hospitalized at Fourth Affiliated Hospital of Guangxi Medical University from June 2014 to May 2017.The best diagnosis cut-off value of tsutsugamushi disease was calculated by receiver operating characteristic (ROC) curve.Results A total of 57 cases of tsutsugamushi disease,40 cases of sepsis,17 cases of acquired immunodeficiency syndrome (AIDS),17 cases of severe community-acquired pneumonia (SCAP),63 cases of common community-acquired pneumonia (CCAP),14 cases of pulmonary tuberculosis (PTB),20 cases of upper respiratory tract infection,13 cases of other infectious fever and 28 cases of non-infectious fever patients were selected.The level of serum PCT in tsutsugamushi disease [0.87 (0.68-1.34) μg/L] was higher than those in AIDS [0.47 (0.20-1.12) μg/L],CCAP [0.17 (0.09-0.51) μg/L],PTB [0.13 (0.05-0.18) μg/L],upper respiratory tract infection [0.23 (0.05-0.48) μg/L] and non-infectious fever [0.09 (0.06-0.13) μg/L],but was lower than those in sepsis [5.00 (1.04-18.78) μg/L] and SCAP [3.35 (0.76-14.41) p,g/L,P ＜ 0.05],while the difference was not significant compared with other infectious fever [0.76 (0.13-1.99) μg/L,P ＞ 0.05].The level of serum β2MG in tsutsugamushi disease [(5.67 (4.47-7.90) mg/L] was higher than those in sepsis [2.83 (2.10-4.54) mg/L],AIDS [3.85 (3.19-5.22) mg/L],SCAP [3.83 (2.98-5.58) mg/L],CCAP [1.99 (1.51-2.75) mg/L],PTB [1.92 (1.37-3.00) mg/L],upper respiratory tract infection [2.02 (1.25-2.74) mg/L],other infectious fever [2.45 (1.51-4.12) mg/L] and non-infectious fever [2.99 (2.06-4.30) mg/L,P ＜ 0.05].ROC curve showed that the most suitable diagnosis cut-off value of serum PCT in tsutsugamushi disease was 0.53 μg/L,the sensitivity was 94.7％,and the specificity was 60.4％.The critical value of serum β2MG was 3.74 mg/L in diagnosis of tsutsugamushi disease,its corresponding sensitivity and specificity were 91.2％ and 75.9％,respectively.The sensitivity and specificity of combined serum PCT and β2MG in diagnosis of tsutsugamushi disease was 87.7％ and 86.3％,respectively.Conclusion Combined detection with serum PCT and β2MG can improve early diagnosis of tsutsugamushi disease.