The utility of RDW in discrimination of sarcoidosis and tuberculous lymphadenitis diagnosed by ebus.

Abstract

Erythrocyte distribution width (RDW) is an important indicator of anisocytosis, which is used in the differential diagnosis of anemia and is easily accessible in the complete blood count results. Increased RDW values in coronary artery diseases, pulmonary hypertension and malignancies were detected in the studies. We aimed to demonstrate the usefulness of blood RDW level for the differential diagnosis of granulomatous lymphadenitis associated with tuberculosis and sarcoidosis in our study. A total of 331 patients, 229 with sarcoidosis (stage I and stage II) and 102 with TB-LA and 50 healthy control group were included in the study. The biopsies were obtained via EBUS-TBNA from 705 lymph nodes of 331 patients. Of tissue diagnosis was non-erosive granulomatous inflammation patients with tuberculosis negative proved by microbiological tests were accepted as sarcoidosis after other causes of granulomatous disease were excluded. Of the sarcoidosis patients, 169 (73.7%) were in stage I, and 60 (26.3%) were in stage II. The mean RDW was 14.31 (± 1.6) in the stage I group, 14.99 (± 2.3) in the stage II group, 14.11 (± 2.0) in the TB-LA group, and 13.89 (± 1.3) in the control group. There was a significant difference between the stage II group and the stage I, TB-LA, and control groups (p< 0.05 for all). There was a significant difference in the C-reactive protein levels between the TB-LA and stage I groups (p< 0.01). The eritrocyte sedimentation rate values were higher in the TB-LA group than in both the stage I and stage II groups (p< 0.05). This is the first study to demonstrate the diagnostic value of RDW in patients with TB-LA and sarcoidosis (Stage I-II) patients diagnosed by EBUS-TBNA. Higher RDW in stage II sarcoidosis than in stage I, TB-LA and control group is related with parenchymal involvement and indicates active inflammation.