Immunological interactions of tuberculosis with drugs and substance use: a systematic review and update

Abstract

Background: Illicit drug and substance use exacerbates tuberculosis (TB) pandemic and complicates management of the disease. Cytokines play a crucial role in TB infection, and recreational drugs of abuse present a confounder in the understanding of immunology of TB. Therefore, this review presents an updated summary describing the immunological link between illicit drug use and TB. Methods: Information was obtained from previous research findings via Medline search (1990-2015) using the headings tuberculosis, drug interactions, cytokine alterations, prevalence of TB and illicit drug use. In addition, Google scholarly articles and PubMed citations were included in our search. Discussion: Recreational drug induced immunosuppression hastens TB progression among habitual substance users. Additionally, substance consumption in the context of TB infection alters cytokine production and the ensuing immune responses. In this regard, understanding these interactions forms an integral component in improving clinical outcomes among this cohort. Conclusions: Drug and substance abuse aggravates TB pandemic and remains a hindrance to effective TB diagnostic and therapeutic strategies. As such, poor adherence to TB treatment and interactions with drugs of abuse remain a hallmark for drug resistance that poses a unique setback in the fight against the world epidemic. In addition, substance consumption promotes derangement in inflammatory responses implicated in TB immunopathogenesis. This review necessitates clear identification on contribution of each substance towards TB predisposition and cytokine dysregulation while adjusting for confounders.