Demographic, clinical and laboratory characteristics of extrapulmonary tuberculosis: Eight-year results of a multicenter retrospective study in Turkey.

Extrapulmonary tuberculosis (EPTB) is an important public health problem due to its diverse clinical presentations, diagnostic complexities, and significant impact on patient outcomes and public health. Our study aimed to understand the sociodemographic, clinical, and laboratory characteristics as well as diagnostic and treatment modalities of adult patients with EPTB. This is a multicentric retrospective study that covers patients with EPTB cases followed up from January 2015 to December 2022 among tuberculosis (TB) dispensaries and Infectious Diseases and Clinical Microbiology clinics of 15 hospitals located in various regions of Turkey. The study included 64.6% women with a mean age of 44 years and a mortality rate of 3.5% within 1 year of diagnosis. Initial constitutional symptoms were predominantly fatigue (57%) and anorexia (53.7%). The most commonly affected sites were the lymph nodes (49.1%) and pleura (9.7%). The lumbar region was particularly involved in cases with spinal TB. Diagnostic findings included acid-fast bacilli positivity in 27.5% of cases, tuberculosis polymerase chain reaction positivity in 41%, elevated adenosine deaminase levels in 91.2% (especially in pleural and peritoneal fluids), and mycobacterial culture positivity in 40.9%. Pathology slides showed granulomatous inflammation in 97.7%. Increased C-reactive protein (CRP) levels correlated with the number of organs affected. Anti-TB treatment-related hepatotoxicity was detected in 8.9% of patients. In this study, it is important to note that the lumbar region is predominantly affected with involvement in spinal region. CRP level was consistent with the number of organ involvements and was one of the most critical results of this study.