CD4 and HIV infectious disease: The CD4 cell count was classified into four categories in accordance with the treatment guidelines for HIV infections,17 as this style of classification is accepted globally.18 The grouping was performed using the number of CD4+ T-cells in 1 mm3 of patient’s blood, and the four categories were as follows: <200, 200–349, 350–499, and ≥500 cells/mm3.