In 2008, Deps and Lockwood [4] proposed a definition of leprosy as an IRIS to facilitate its identification and recognition: (1) leprosy and/or leprosy reaction presenting within the six months of starting HAART; (2) advanced HIV infection; (3) low CD4+ T lymphocyte (CD4) count before starting HAART; (4) CD4 count increase after HAART initiation. Here, CD4 is linked to HIV infectious disease.