Site directed mutagenesis of CEACAM1-4L receptor gene was performed using the QuickChange® Site Directed Mutagenesis Kit (Stratagene, La Jolla, CA, USA) according to the manufacturer's instructions. Primers (Table 1) were used to introduce the desired mutations into the pRc/CMV-CEACAM1-4L construct (kindly provided by Professor Wolfgang Zimmermann). Following sequencing to ensure the desired substitution had been obtained, the pRc/CMV-CEACAM1-4L construct was transiently transfected into COS-1 cells for functional analysis using DEAE dextran method described previously (Teixeira et al., 1994; Virji et al., 1996a) .  Immune reconstitution inflammatory syndrome (IRIS): review of common infectious manifestations and treatment options The immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients initiating antiretroviral therapy (ART) results from restored immunity to specific infectious or non-infectious antigens. A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating therapy characterizes the syndrome. Potential mechanisms for the syndrome include a partial recovery of the immune system or exuberant host immunological responses to antigenic stimuli. The overall incidence of IRIS is unknown, but is dependent on the population studied and its underlying opportunistic infectious burden. The infectious pathogens most frequently implicated in the syndrome are mycobacteria, varicella zoster, herpesviruses, and cytomegalovirus (CMV). No single treatment option exists and depends on the underlying infectious agent and its clinical presentation. Prospective cohort studies addressing the optimal screening and treatment of opportunistic infections in patients eligible for ART are currently being conducted. These studies will provide evidence for the development of treatment guidelines in order to reduce the burden of IRIS. We review the available literature on the pathogenesis and epidemiology of IRIS, and present treatment options for the more common infectious manifestations of this diverse syndrome and for manifestations associated with a high morbidity. Since its introduction, ART has led to significant declines in AIDS-associated morbidity and mortality [1] . These benefits are, in part, a result of partial recovery of the immune system, manifested by increases in CD4 + T-lymphocyte counts and decreases in plasma HIV-1 viral loads [2] . After initiation of ART, opportunistic infections (OI) and other HIV-related events still occur secondary to a delayed recovery of adequate immunity [3] .