Levels of nitric oxide, gamma interferon and interleukin-12 in AIDS patients with toxoplasmic encephalitis.
The production of nitric oxide (NO) by macrophages is important for the killing of intracellular pathogens, such as Toxoplasma gondii. Gamma interferon (IFN-gamma) and lipopolysaccharide stimulate NO production. The aim of this study was to investigate the importance of NO, IFN-gamma and interleukin-12 (IL-12) in the host immune response in AIDS patients suffering from toxoplasmic encephalitis (TE). It was demonstrated that the production of NO, detected as nitrite/nitrate in the sera and in the cerebrospinal fluid (CSF) of 32 AIDS patients with TE, was normal. In addition, levels of IFN-gamma in the sera and in the CSF of patients with TE were not increased. In contrast, serum levels of IL-12 in these patients were significantly increased (6.5 +/- 7.1 pg/ml; P = 0.0368), compared to the control patients (1.7 +/- 3.5 pg/ml). Furthermore, increased but not significant levels of IL-12 were also observed in the CSF of patients with TE (2.2 +/- 4.7 pg/ml; controls: 0.5 +/- 1.9 pg/ml). The results of this study indicate that reactivation or recurrence of T. gondii infection in HIV-1-infected patients is probably due to a down-regulation of IFN-gamma along with a resulting non-optimal NO activity.
Torre
D
D
Div. of Infectious Diseases, Regional Hospital, Varese, Italy.
Zeroli
C
C
Ferrario
G
G
Pugliese
A
A
Speranza
F
F
Orani
A
A
Casari
S
S
Bassi
P
P
Poggio
A
A
Carosi
G P
GP
Fiori
G P
GP
D017088:AIDS-Related Opportunistic Infections / Q000097:blood / Q000134:cerebrospinal fluid / Q000276:immunology / Q000378:metabolism*; D000328:Adult; D000818:Animals; D004660:Encephalitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D018664:Interleukin-12 / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D009566:Nitrates / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism; D009569:Nitric Oxide / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D009573:Nitrites / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism; D014122:Toxoplasma / Q000276:immunology; D016781:Toxoplasmosis, Cerebral / Q000097:blood / Q000134:cerebrospinal fluid / Q000276:immunology / Q000378:metabolism*
D009566:Nitrates; D009573:Nitrites; D018664:Interleukin-12; D009569:Nitric Oxide; D007371:Interferon-gamma