The Value Of NLR And TB-IGRA In The Differential Diagnosis Of Pulmonary Sarcoidosis And Tuberculosis

Objective Differential diagnosis between pulmonary sarcoidosis and tuberculosis has always been a problem in respiratory and tuberculosis clinicians.Both exist great similarities not only on clinical manifestations and imaging findings but also on pathology,but the treatment is completely different. There is no clinical diagnosis technology can meet the needs so far.This paper is to evaluate the value of neutrophil-to-lymphocyte ratio (NLR) and peripheral blood TB-IGRA in the differential diagnosis of pulmonary sarcoidosis and tuberculosis. Tuberculosis antibody (TB-Ab)、erythrocyte sedimentation rate (ESR)、C-reaction protein (CRP) and serum albumin (ALB) level of the two groups were detected at the same time to observe their differences between pulmonary sarcoidosis and tuberculosis groups to assist the identification.Methods From January 2011 to September 2014,70 pulmonary sarcoidosis and 62 pulmonary tuberculosis patients in Shandong Provincial Hospital were enrolled in the study according to inclusion and exclusion criteria strictly. The NLR was calculated from the differential count by dividing the absolute neutrophil count by the absolute lymphocyte count.Due to the fact that the introduction of TB-IGRA testing technology was in December 2012 in our hospital, only 46 sarcoidosis and 42 tuberculosis patients among them underwent TB-IGRA test. TB-Ab、ESR、CRP and ALB level of the two groups were detected at the same time to facilitate the differenciation.Results Twenty seven of the sarcoidosis group were men and 43 were female.The median age was 51 years.Of the tuberculosis group,42 patients were men and 20 were female.The median age was 59 years.The median age was similar in both groups(P=0.091>0.05),while sex of the two groups had significant differences (P=0.001),the majority of the sarcoidosis group were female.ESR, the positive rate of CRP and TB-Ab were significantly higher and albumin was significantly lower in the tuberculosis group compared with sarcoidosis(for all parameters P<0.001). Among the 46 pulmonary sarcoidosis patients,the TB-IGRA result was positive in 10 patients (21.7%), while among the 42 pulmonary tuberculosis patients, the TB-IGRA result was positive in 37 patients (88.1%) (P<0.001).The NLR was (2.52±1.06) in sarcoidosis group,which was lower than in tuberculosis group(4.31±2.34) (P<0.001) The cut-off value of NLR was 2.77,while its sensitivity and specificity were 74.2% and 71.4%. The sensitivity of the combined detection of NLR and TB-IGRA was 92.9% (39/42)Conclusion1. As a new inflammation index, NLR has a certain value in the identification of pulmonary sarcoidosis with tuberculosis.It’s detection method is simple and fast, and has low cost, and what’s more, most basic-level hospitals can use it at any time, which makes the practical value bigger.2. TB-IGRA in the differential diagnosis of pulmonary sarcoidosis and tuberculosis has high sensitivity and specificity.3. NLR combined with TB-IGRA can further improve the sensitivity, so the combination of NLR and TB-IGRA is a potential method for the differentiation of pulmonary sarcoidosis from tuberculosis.4. Detecting TB-Ab、ESR、CRP and ALB level of the two groups at the same time can assist the differenciation.5. NLR can provide a new idea for the differential diagnosis of granulomatous diseases.