Table 1.

Differences between the studies made on the correlation between programmed death-1 expression and clinical outcome

Ref.	No. of patients	Mode of transfection	Symptoms	PD-1 expression levels in acute infection	PD-1 expression levels in resolved patients
Urbani et al[16]	19	Sexually transmission	Symptomatic	High	Decreased
Kasprowicz et al[17]	37	Sexually transmission	Symptomatic	High	Irrespective
Rutebemberwa et al[62]	20	Injection drug use	Asymptomatic	High	Decreased

PD-1: Programmed death-1.