CD4 and coinfection: The combined immunological profile—persistent B cell lymphopenia, CD4 T cell/Treg depletion, and disrupted CD4/CD8 ratios—defines a distinctive immunopathological signature in moderate-to-severe cases, resembling immunological patterns in HIV/EBV co-infections (Richard et al., 2010; Rosado-Sanchez et al., 2017).