Approximately 10% of patients with extra pulmonary tuberculosis (TB) have skeletal involvement and TB spine accounts for 50% of cases of skeletal TB. Neuroimaging guided needle biopsy or surgical biopsy from the affected site can provide material for histopathologic and microbiologic diagnosis.There is increasing incidence of drug resistant TB cases in India and across the globe. Genexpert is a cartridge based fully automated test which can simultaneously detect TB and rifampicin resistance within few hours. World Health Organisation (WHO) has given conditional recommendation for use of Xpert MTB/RIF as a replacement test for testing of non respiratory specimens from patients presumed to have extra pulmonary TB.
This is a prospective observational study conducted in a tertiary health care institute, Mumbai, India from January 2014 to May 2015. Patients with MRI suggestive of tuberculosis underwent image guided biopsy, surgical biopsy or pus aspiration. Material obtained was sent for Ziehl – Neilsen Stain, Real Time PCR (CBNAAT, Genexpert, Cepheid), Mycobacterium Tuberculosis (MTB) culture (automated liquid culture, Bac T Biomerieux) and histopathology.
Total of 40 patients were diagnosed with spinal TB based on clinical and MRI findings. There were 18 males and 22 females of age group ranging between 10 – 87 years (median – 48 years). Image guided biopsy was done in 8 patients, Surgical operative biopsy was done in 22 patients. Biopsy material was available in 28 patients for Microbiologic tests. Of these Genexpert was done in 24 patients and Mycobacterial culture was done in 28 patients. Genexpert was positive in 18 patients and culture was positive in 18 patients. In 10 patients Anti TB treatment was started on basis of MRI alone as tissue diagnosis was not possible and clinical response was assessed. There were 6 patients who were found to have Multi Drug Resistant TB (MDR – TB) of which there were 5 males and 1 female. 4 were detected by Genexpert MTB/RIF assay and later confirmed on MTB culture and sensitivity.
There is increasing incidence of MDR – TB. Early identification can lead to prompt modification of treatment regimen, so that neurologic deficits and spine deformities can be prevented. Tissue diagnosis, Genexpert, Mycobacterial culture should form part of diagnostic workup of spinal TB.
S. Shah, None
M. Bapat, None