Clinical Features and Diagnostic Delay of Tuberculosis (TB) in Patients with Acute Myeloid Leukemia. (AML)
Authors: Bravo Villa Veronica , Martínez Moreno Emmanuel , Zapata Nidia 
Published: November 2019

Introduction
Patients with AML are inmmunocompromised because of the disease itself and the use of chemotherapy, increasing endemic opportunistic infections. The main complication is secondary infectious diseases, which we have to consider TB. In cancer patients infected with TB frequently manifest more atypical. Clinical signs and symptoms include lung disease which is still the most commonly involved site, extra pulmonary tuberculosis is not uncommon. Even that we're in an endemic country we still have some delay in the diagnosis of such disease.
Objective
To characterize the clinical and factors that contributes to the delay on the diagnosis of tuberculosis in patients with AML.
Methods
We did a chart review of patients with the diagnosis of TB and AML in the Instituto Nacional de Cancerologia, Mexico City, from January 2014 to July 2019. We analyze the clinical presentation of and the time to diagnosis TB in those patients.
Results
We analyze a cohort of 5 patients, three male and two female with a median age of 44 years old. The majority of patients were on induction chemotherapy. The main clinical presentation was persistent fever that begins in the nadir of chemotherapy. We observed a median of days for the diagnosis of tuberculosis of 37 days (9-82), the diagnosis was made by histopathology supported by special stains, and were required at least two biopsies for the diagnosis. One patient has pulmonary tuberculosis, one nodal presentation, two have a hepatosplenic presentation, and in the last patient was conclude latent TB. Just in one patient was available the microbiological identification, Mycobaterium bovis. Four patients started the approved treatment in Mexico, intensive phase with rifampicin, pyrazinamide, ethambutol and isoniazid. One patient develop Drug induce liver injury (DILI) so she couldn't continue the first line treatment and have to receive the second line which it is not standardize. After the initiation of the treatment, patients went out of fever and improve their condition. The patients were followed during the maintenance phase with rifampicin, and isoniazid. All of the patients are alive at the moment of the study.
Conclusion:
Febril neutropenia is a common complication in patients with AML, and in patients with persistent fever, tuberculosis should be include in the differential diagnosis. In México we have limited access to all the diagnostic tools available in our center. Culture is not always a way to identify TB, most of our patients were diagnosed by biopsy, median number of procedures were 3. Patient number 5 was followed by the infectology service after the whole protocol of culturing TB were concluded with no evidence of the disease and they decide to stop the treatment, and they manage the patient as latent TB. The availability of the techniques is the main factor which contributes to the diagnosis delay of TB. After the treatment was started, patients have a significant clinical improvement.

Disclosures
No relevant conflicts of interest to declare.