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.

Meningoencephalitis caused by human herpesvirus-6 in an immunocompetent adult patient: case report and review of the literature.

Human herpesvirus-6 (HHV-6) is the etiologic agent of roseola infantum, and has been implicated as a possible cause of encephalitis in pediatric and adult patients. A case of meningoencephalitis in an otherwise healthy, immunocompetent 59-year-old woman is described. The diagnosis of HHV-6 meningoencephalitis was confirmed by detecting viral DNA in cerebrospinal fluid collected in the acute stage of the disease by polymerase chain reaction. The patient was treated with acyclovir and recovered without any sequelae. The current knowledge of the pathophysiology, clinical course and outcome of HHV-6 meningoencephalitis in immunocompetent adult patients is also reviewed.

Levels of circulating nitrate/nitrite and gamma interferon not increased in uncomplicated malaria.

The purpose of this study was to evaluate nitric oxide (NO) activity in patients with uncomplicated malaria. Lipopolysaccharide and gamma interferon (IFN-gamma) are potent inducers of NO by inducing production of NO synthase. NO activity was determined by measuring serum levels of nitrite/nitrate (metabolic end products of NO), and IFN-gamma in patients with uncomplicated malaria, mostly caused by Plasmodium falciparum. Neither serum levels of nitrite/nitrate nor of IFN-gamma were significantly increased in patients with uncomplicated malaria, especially in patients with P. falciparum infection, and in those with high parasitaemia. These results show that NO cannot play a role in uncomplicated malaria, and it is still debatable if NO production in this infection has beneficial or detrimental effects.

Serum concentrations of nitrite in patients with HIV-1 infection.

AIMS: To measure circulating concentrations of nitrite in patients with HIV-1 infection. METHODS: Nitrite concentrations were measured using the Griess reaction adapted to microtitre plates in the serum of 10 asymptomatic HIV-1 positive patients, 33 patients with AIDS with cerebral disorders, 17 patients with AIDS with pulmonary involvement, and in eight patients with AIDS with other disorders. Nitrite concentrations were also measured in bronchoalveolar lavage (BAL) fluid and cerebrospinal fluid (CSF) of patients with AIDS with pulmonary involvement and cerebral disorders, respectively. RESULTS: Increased serum concentrations of nitrite were observed in patients with pulmonary involvement, and in particular in serum and in BAL samples of patients with interstitial pneumonia (36.2 (26.2) mumol/l and 0.3 (0.4) mumol/l, respectively). Increased serum concentrations of nitrite were also noted in patients with retinitis caused by infection with cytomegalovirus. Serum nitrite concentrations were also raised in patients with cerebral toxoplasmosis, whereas normal serum concentrations were found in patients with HIV-1 encephalopathy and cryptococcal meningitis. Nitrite concentrations in CSF were not raised in patients with cerebral disorders. CONCLUSIONS: These results suggest that production of nitrite in patients with AIDS with concomitant opportunistic infections may be part of the host defense against opportunistic organisms.

Aseptic meningitis caused by Leptospira australis.

Meningeal involvement in leptospiral infection is quite common, usually mild and often overlooked. In contrast, cases of isolated involvement of the central nervous system, including aseptic meningitis, have been reported only rarely. A case of a patient with acute aseptic meningitis caused by Leptospira australis serovar bratislava is reported. This is believed to be the first report of aseptic meningitis due to Leptospira australis. This case indicates the need to consider human leptospirosis in the differential diagnosis of aseptic meningitis.

Levels of circulating fibronectin receptor in adult and pediatric patients with human immunodeficiency virus type 1 infection.

We found a significant increase in fibronectin receptor (FNR) levels in the sera of adult human immunodeficiency virus type 1 (HIV-1)-infected patients, especially in those with AIDS (1,026.9 +/- 583.9 ng/ml; P < 0.0001). In contrast, AIDS patients with neurologic disorders and HIV-1-seropositive patients showed normal levels of FNR in serum. In addition, HIV-1-infected children showed increased levels of FNR in serum (824.4 +/- 333.5 ng/ml; P = 0.03). We suggest that an increase of FNR levels in AIDS patients is related to enhanced expression of FNR on HIV-1-infected cells.

[The use of intravenous 7S immunoglobulins at high doses in HIV-related immunological pathology]. / Impiego di immunoglobuline 7S per via endovenosa ad alte dosi nella patologia immunologica HIV-correlata.

24 AIDS patients, both males and females, aged from 3 to 52 years, received high-dose i.v. 7S immunoglobulin (220-400 mg/kg, range 7.5-20 g/die). These patients were affected by HIV-related thrombocytopenia and antibiotic-resistant severe hyperpyrexia; three HIV-positive asymptomatic children with severe immunodeficiency were treated to prevent opportunistic infections. I.V. 7S immunoglobulins were well tolerated, and were found to be very effective in the therapy of thrombocytopenia and in the prevention of opportunistic infections in the asymptomatic children.

Serum levels of interleukin-1 alpha, interleukin-1 beta, interleukin-6, and tumor necrosis factor in patients with acute viral hepatitis.

Serum levels of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in patients with acute viral hepatitis were investigated. Twelve patients suffering from acute viral hepatitis were studied; 8 patients presented with acute hepatitis B, 2 patients with acute hepatitis A, and 2 patients with acute hepatitis C. Serum levels of IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha were significantly increased in all patients with acute viral hepatitis. Decreased serum levels of all cytokines were noted in four patients with acute hepatitis B during the recovery phase of infection. In addition, IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha were undetectable at the end of a follow-up period of 6 months. Our study shows that increased levels of IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha are probably related to hepatitis activity and thus may have some role in hepatocytic injury.

Cerebrospinal fluid concentration of fibronectin in patients with HIV-1 infection and central nervous system disorders.

AIMS: To evaluate the fibronectin concentrations in the cerebrospinal fluid of HIV-1 infected patients with central nervous system disorders. METHODS: Fibronectin was determined by an immunoturbidimetric assay in 41 HIV-1 infected patients with AIDS dementia complex, progressive multifocal leucoencephalopathy, and opportunistic infections. RESULTS: A significant decrease in fibronectin concentrations in the cerebrospinal fluid of patients with AIDS and dementia complex and progressive multifocal leucoencephalopathy was observed, as well as in those with opportunistic infections of the central nervous system (p < 0.0001). In particular, a significant decrease in fibronectin concentration in cerebrospinal fluid was observed in patients with cerebral toxoplasmosis and cryptococcal meningitis (p < 0.0001). CONCLUSIONS: Because fibronectin can bind to several viruses, fungi, and protozoa, it is conceivable to suppose that the consumption of fibronectin in the cerebrospinal fluid of patients with neurological disorders may be related to the binding of fibronectin to HIV itself, or to viral proteins, or to organisms responsible for opportunistic infections.

Interferon-gamma levels in serum and bronchoalveolar lavage fluid of mice infected with Bordetella pertussis.

The adherence of Bordetella pertussis to respiratory cilia and its survival in neutrophils and macrophages is crucial to the pathogenesis of whooping cough. To investigate the role of endogenous interferon (IFN)-gamma in acute infection, levels of IFN-gamma in bronchoalveolar lavage (BAL) fluid of mice infected intranasally with B. pertussis were determined. Since pertussis toxin is released during infection by B. pertussis either locally or systemically, serum levels of IFN-gamma in mice injected intravenously with pertussis toxin were also determined. A persistent and significant increase of IFN-gamma levels with concomitant peripheral blood lymphocytosis was observed after 5 and 10 days. The results of this study showed an early but transitory production of endogenous IFN-gamma in BAL fluid of mice infected with B. pertussis.

Treatment of AIDS-related refractory diarrhoea with octreotide.

We evaluated the effect of octreotide, a long-acting synthetic analogue of native somatostatin, on bowel frequency in 13 patients with AIDS-associated refractory diarrhoea. Cryptosporidium enteritis and cytomegalovirus colitis were the most common causes of diarrhoea. All patients received 100 micrograms t.i.d. octreotide subcutaneously for 1 week; those who did not improve were given 250 micrograms t.i.d. for a further 7 days. Bowel frequency returned to normal in 1 patient, who was affected with cryptosporidiosis, and decreased by more than 50% in 7 others, another patient improved on the higher dose. In 1 case, the beneficial effect disappeared after 10 days of treatment. No major adverse events due to the therapy were observed. We conclude that octreotide has a potential therapeutic use in severe AIDS-related refractory diarrhoea. How to identify patients who may respond remains unknown at present.

Acute-phase proteins and levels of interleukin 1B, interleukin 6, tumor necrosis factor alpha, and interleukin 8 in children with pertussis.

OBJECTIVE: To determine serum levels of acute-phase proteins and interleukin 1B, interleukin 6, tumor necrosis factor alpha, and interleukin 8 in children with pertussis. DESIGN: Cross-sectional study. SETTING: Divisions of Infectious Diseases, Regional Hospital, and Pediatrics, University of Pavia, Varese, Italy. PARTICIPANTS: Eight children with pertussis, six with acute febrile infections, and eight healthy control children matched for sex, age, and time presentation over a 32-month study period. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: An immunoenzymatic assay was used to detect serum levels of all cytokines. Normal values of C-reactive protein, alpha 1-acid glycoprotein, and erythrocyte sedimentation rate were observed in the serum of patients with pertussis. The mean (+/- SD) detectable levels of tumor necrosis factor alpha (65.0 +/- 50.4 pg/mL) and interleukin 6 (32.3 +/- 17.8 pg/mL) were observed in the serum of patients with pertussis. In contrast, a nonsignificant increment of interleukin 1B levels (66.5 +/- 83.7 pg/mL) and interleukin 8 levels (12.7 +/- 17.8 pg/mL) was noted in the serum of the same patients. Increased and significant levels of all four cytokines were noted in most of the serum samples of patients with acute febrile infections. CONCLUSIONS: Acute-phase response is absent in patients with pertussis, whereas detectable and significant serum levels of tumor necrosis factor alpha and interleukin 6 were observed in some such patients.

Ventriculoatrial shunt infection caused by Staphylococcus warneri: case report and review.

Staphylococcus warneri, a coagulase-negative species, is a rare cause of infection of cerebrospinal fluid (CSF) shunts. In one recently studied case of ventriculoatrial shunt infection, the repeated isolation of S. warneri (i.e., from all of six blood cultures and from a CSF sample obtained directly from the valve of the shunt) suggested that this organism can be clinically significant. Review of the literature clearly indicates that S. warneri is a rare but potentially dangerous pathogen in both immunocompetent and immunocompromised hosts with prosthetic devices. The removal of the infected shunt in association with systemic and local antibiotic administration probably constitutes the treatment of choice in such infections. Further experience is needed to determine the prevalence and the pathogenic significance of S. warneri and of the related organisms Staphylococcus epidermidis and Staphylococcus saprophyticus in patients with prosthetic devices.

Cerebrospinal fluid levels of IL-6 in patients with acute infections of the central nervous system.

Interleukin-6 (IL-6) activity was measured in the cerebrospinal fluid (CSF) of patients with acute bacterial or viral meningitis and in AIDS patients with various cerebral disorders. Increased levels of IL-6 were detected in the CSF of patients with bacterial meningitis. On the contrary, most of the samples from patients with viral meningitis (predominantly caused by mumps virus) had no detectable IL-6 activity in CSF. A moderate increase of IL-6 levels was detected in the CSF of AIDS patients with AIDS dementia complex (ADC), progressive multifocal leukoencephalopathy and cerebral toxoplasmosis. Moreover, higher levels of IL-6 were detected in the CSF of patients with cryptococcal meningitis. We conclude that the initial events of CSF inflammation in patients with acute viral meningitis are different from those in patients with acute bacterial meningitis, and the role of IL-6 is less critical to the process.

Cerebrospinal fluid concentration of fibronectin in meningitis.

Fibronectin concentrations in the cerebrospinal fluid were assessed in 20 patients with acute meningitis using a turbidimetric immunoassay. A significant increase in fibronectin concentrations was observed in patients with bacterial meningitis; decreased concentrations were observed in patients with viral meningitis. The determination of fibronectin concentration in patients with bacterial meningitis may represent a useful marker in differentiating bacterial from viral meningitis.

Dermatologic manifestations of AIDS in children.

A wide variety of clinical expressions of the acquired immunodeficiency syndrome (AIDS) has been apparent from the earliest case reports in adult patients and pediatric patients. Both human immunodeficiency virus (HIV) infection and AIDS in children are associated with an increased prevalence of several dermatologic manifestations. In this article we present a review of the recent literature describing the cutaneous manifestations of pediatric AIDS. The cutaneous manifestations of AIDS in children can be divided into three categories: (1) neoplastic manifestations; (2) viral, bacterial and fungal manifestations, and (3) vascular lesions and other manifestations. Pediatricians as well as dermatologists may be the first physicians to recognize and to treat the clinical manifestations of AIDS.

Plasma fibronectin concentrations in patients with human immunodeficiency virus infection.

Plasma fibronectin (PFN) concentrations were assessed in 21 patients with AIDS, in seven with AIDS-related complex (ARC), in 17 asymptomatic seropositive patients, and in 36 age and sex matched healthy control subjects. A single radial immunodiffusion technique was used to determine PFN concentration. A significant decrease in PFN concentrations was observed in patients with ARC and AIDS (especially in those patients with Pneumocystis carinii pneumonitis). On the other hand, normal PFN concentrations were observed in asymptomatic seropositive patients. The determination of PFN concentration in patients with AIDS and ARC may contribute to the diagnosis of such patients.