Introduction
Currently, more than 1.7 billion people (approximately 22% of the world
population) have a Mycobacterium tuberculosis (MTB) infection
[1]. Tuberculosis (TB) caused 1.5 million deaths in 2020 and is the
13th leading cause of death worldwide. Age is a major risk factor for
pulmonary TB [2] and is associated with a longer treatment delay and
higher mortality rate [3]. Because of the global increase in the
aging population, TB must be diagnosed and treated quickly. However, the
risk of adverse reactions during anti-TB treatment is higher in older
adults, especially in patients receiving rifampin (RIF) or pyrazinamide
(PZA) [4, 5]. The situation is worse in Taiwan because Taiwan’s
population is aging at a rate more than twice that in Western countries
[6]. The occurrence of adverse reactions may compromise drug
adherence and worsen anti-TB treatment outcomes [7].
Acute kidney injury (AKI) is a rare and severe complication that can
interrupt anti-TB treatment and cause permanent kidney damage [8].
Among first-line anti-TB drugs, the most common offending drug for AKI
is RIF [8-10]. However, other drugs, such as isoniazid (INH) and
ethambutol (EMB), are also associated with AKI [11, 12]. So far
prospective studies evaluating the incidence of AKI during anti-TB
treatment have not been conducted. Retrospective cohort studies on TB
treatment have reported an AKI incidence of approximately 0.05% to
7.1% [13, 14]. However, these studies have not followed renal
function regularly, and one study performed a laboratory survey only
when patients exhibited gastrointestinal (such as nausea and vomiting)
or flu-like symptoms [15]. Furthermore, the definition of kidney
injury has differed between these studies [8, 13, 16]. Predictive
factors for AKI, especially in an aging population, also remained
unclear. Therefore, we conducted this prospective cohort study to
evaluate the incidence of AKI during first-line anti-TB treatment and
explored the risk factors for this complication.