Reversal Reaction as a Manifestation of Immune Reconstitution Inflammatory Syndrome

Abstract

Leprosy is a chronic infectious disease cause by the Mycobacterium leprae. The disease is found worldwide, especially, in countries situated in tropical and subtropical regions. According to the reports of the World Health Organization (WHO) the global registered prevalence of leprosy at the beginning of 2010 stood at 211,903 cases, whereas the number of new cases detected during 2009 was 244,796 (World Health Organization [WHO], 2010). Although there has been a declining trend in prevalence and detection of new cases, leprosy is still a public health problem in Brazil. In 2009, the prevalence rate of the disease was 1.99 per 10,000 habitants and 37,610 new cases of leprosy were detected in the entire country (Brazilian Ministry of Health, 2011). On the other hand, the Human deficiency Virus (HIV) infection is one of the greatest health problems of the world due to its pandemic nature and high morbidity and mortality rates. In the absence of treatment, the Acquired immunodeficiency syndrome (AIDS) usually leads to premature death. The World Health Organization estimates that 33.3 million people were living with HIV in the end of 2009 around the globe and 2.6 million people became HIV infected in 2009 (Joint United Nations Programme on HIV/AIDS [UNAIDS], 2010). In Brazil, the AIDS epidemic has been maintained stable in the last few years. In 2009, the incidence rate was 20.1 per 100,000 habitants and 38,538 new cases of AIDS were registered in the country (Brazilian Ministry of Health, 2010). Although the prevalence rate of coinfected individuals has never been estimated neither in Brazil nor worldwide, leprosy and the HIV infection seem to overlap in a number of countries, mainly in Africa and Asia continents. As observed with others Mycobacterial infections, it has been speculated that HIV and Mycobacterium leprae coinfection could exacerbate the pathogenesis of leprosy lesions and/ or could lead to increased susceptibility of leprosy. However, up to date, HIV infection has not seemed to modify the epidemiology and the natural course of leprosy (Ustianowski et al., 2006). In contrast, initiation of anti-retroviral treatment has been reported to be associated with activation of sub-clinical M. leprae infection and exacerbation of existing leprosy lesions (Menezes et al., 2009).