# Tuberculosis Under Biotherapy in Patients with Spondyloarthritis: Data from the Moroccan Biotherapy Registry (RBSMR) during 3 Years of Follow Up

## TL;DR

This study finds that patients with spondyloarthritis on biotherapy, especially TNF-inhibitors, have a higher risk of active tuberculosis, highlighting the need for careful monitoring.

## Contribution

The study provides new incidence data on tuberculosis in Moroccan spondyloarthritis patients on biotherapy and evaluates LTBI reactivation rates.

## Key findings

- The incidence of active tuberculosis was 17/1000 patient-years in patients on TNF-inhibitors.
- Diabetes and prior use of multiple TNF-inhibitors were significantly associated with active tuberculosis.
- Only 4.5% of patients with prior latent tuberculosis infection developed active tuberculosis after chemoprophylaxis.

## Abstract

Biologics agents may lead to a significant risk of infection, including tuberculosis, particularly in endemic countries. This study aims to determine the incidence and characteristics of active tuberculosis in spondyloarthritis patients undergoing biotherapies and estimate the rate of reactivation of latent tuberculosis infection (LTBI).

A prospective multicentre study was conducted based on 3-year data from the Moroccan Register of Biotherapies (RBSMR). We determined the incidence rate of tuberculosis during follow-up and performed a comparison with patients in whom tuberculosis was not detected. Screening for LTBI prior to the initiation of biotherapy was analysed, and the reactivation rate was determined at the 3-year follow-up.

194 patients with SpA were included. 98.8% of the patients received TNF-inhibitors, and 6.6% had a history of treated tuberculosis infection. After 3 years of follow-up, 10 cases of active tuberculosis were recorded with an incidence of 17/1000 patient-years. All of these patients were on TNF-inhibitors. diabetes was significantly higher in patients with active tuberculosis (P=0.02), as was the prior use of at least two TNF-inhibitors (P=0.03). Before initiating biotherapy, 22.6% of individuals were found to have LTBI and received chemoprophylaxis. After a 3-year follow-up, only 2 (4.5%) cases of active TB were noted in patients previously treated for LTBI whereas the other 8 cases had negative screening.

This study suggests that patients undergoing biotherapy, particularly TNF-inhibitors have a higher incidence of active tuberculosis compared to the general population. Rheumatologists should be aware of both reactivation LTBI and de novo tuberculosis.