Venzor et al. (1997) described the case of an ICL patient with PJP, CMV and Candida infection. During the follow-up, the common factor of polymicrobial pneumonia between this case and ours was the CD4+ counts of ≤70 cells μl−1. This suggests that multiple OIs may occur below this CD4+ count cut-off. This evidence concerns the gene CD4 and susceptibility to pneumonia measurement.