Filippo Speranza

Role of Th1 and Th2 Cytokines in Immune Response to Uncomplicated Plasmodium falciparum Malaria

ABSTRACT The relative balance between Th1 and Th2 cytokines appears crucial, since the role of cytokines has been evaluated in several studies by comparison of clinically heterogeneous groups of patients. The aim of this study is to determine the role of proinflammatory Th1 cytokines, interleukin-12 (IL-12) and gamma interferon (IFN-γ), and anti-inflammatory Th2 cytokines, IL-4 and IL-10, in a homogeneous group of patients with uncomplicated Plasmodium falciparum malaria. Levels of IL-12, IFN-γ, Il-4, and IL-10 in serum for 20 adult patients and 15 healthy control subjects were determined by an immunoenzymatic assay. Serum levels of Th1 cytokines, IL-12 (8.6 ± 2.8 pg/ml; controls, 3.2 ± 0.7 pg/ml) and IFN-γ (39.2 ± 67.6 pg/ml; controls, 8.4 ± 6.3 pg/ml), were significantly increased at admission; 3 days later, levels of IL-12 in serum remained significantly high (8.8 ± 2.6 pg/ml), whereas IFN-γ levels returned to control values. The anti-inflammatory response of Th2 cytokines (IL-10 and IL-4) was distinct. Levels of IL-10 in serum were not significantly increased at day 0 and day 3 (306.6 ± 200.4 pg/ml and 56.6 ± 38.4 pg/ml, respectively; controls, 17.4 ± 9.0 pg/ml). In contrast, levels of IL-4 in serum were not increased on admission (3.4 ± 1.2 pg/ml; controls, 2.4 ± 0.8 pg/ml), but at day 3 a moderate and significant increase of IL-4 levels was observed (4.5 ± 1.7 pg/ml). In conclusion, the increase of Th1 cytokine IL-12 and IFN-γ levels during the acute phase of uncomplicated P. falciparum malaria may reflect an early and effective immune response regulated by proinflammatory Th1 cytokines, and in particular IFN-γ may play a role in limiting progression from uncomplicated malaria to severe and life-threatening complications.

Impaired macrophage phagocytosis of apoptotic neutrophils in patients with human immunodeficiency virus type 1 infection.

ABSTRACT Dysfunction of neutrophils (polymorphonuclear leukocytes [PMNL]) and macrophagic cells occurs as a consequence of human immunodeficiency virus type 1 (HIV-1) infection. Macrophages contribute to the resolution of early inflammation ingesting PMNL apoptotic bodies. This study investigated macrophage ability to phagocytose PMNL apoptotic bodies in patients with HIV-1 infection in comparison with uninfected individuals and the effect of HIV Nef protein on apoptotic body phagocytosis to determine if phagocytic activity is impaired by HIV infection. Monocytes/macrophages were isolated from 10 HIV-1-infected patients and from five healthy volunteers, whereas PMNL were isolated from healthy volunteers. Macrophage phagocytosis of apoptotic PMNL was determined by staining of apoptotic bodies with fluorescein-conjugated concanavalin A or with fluorescein-labeled phalloidin. Our data show significant impairment of PMNL apoptotic body macrophage phagocytosis in subjects with HIV-1 infection presenting a concentration of CD4+ T lymphocytes of >200/mm3 and in particular in those with <200 CD4+ T lymphocyte cells/mm3. In addition, HIV-1 recombinant Nef protein is able to decrease phagocytosis of apoptotic PMNL from normal human macrophages in a dose-dependent manner. The results of our study suggest that impaired macrophage phagocytosis of PMNL apoptotic bodies may contribute to the persistence of the inflammatory state in HIV-infected subjects, especially during opportunistic infections that are often favored by defective phagocytic activity.

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.

A retrospective study of treatment of cerebral toxoplasmosis in AIDS patients with trimethoprin-sulphamethoxazole

AIMS OF THE STUDY a retrospective study was designed to evaluate efficacy and tolerance of trimethoprim-sulphamethoxazole (TMP-SMZ) in AIDS patients with cerebral toxoplasmosis (TE). PATIENTS AND METHODS we reviewed 471 patients with AIDS, and we analysed 71 AIDS patients with TE, who received intravenous therapy with TMP-SMZ (TMP: 10 mg/kg/day, SMZ: 50 mg/kg/day) for 4 weeks. RESULTS 35 patients (49.2%) had a complete regression of clinical signs, and a complete resolution of radiological lesions was noted in 41 patients (57.7%). Improvement of clinical signs and radiological lesions were observed in 27 patients (38%), and in nine patients (12.6%), respectively. In contrast, nine patients (12.6%) did not show any clinical change, or worsened. Twenty-two patients (30.9%) suffered from adverse cutaneous reactions, whereas many patients had haematological toxicity. CONCLUSIONS TMP-SMZ seems to be an efficient therapy for TE in AIDS patients, although further prospective, randomized therapeutic trials are required to confirm these results.

In vitro and in vivo induction of nitric oxide by murine macrophages stimulated with Bordetella pertussis

Nitric oxide (NO) exhibits potent antimicrobial activity in vitro. The function of NO in host defenses in vivo, however, is presently unclear. Experiments were undertaken to determine the production of NO in vitro from murine peritoneal and alveolar macrophages, and murine macrophage cell line (J774A.1) stimulated with Bordetella pertussis or pertussis toxin (PT). In addition, we determined circulating levels of NO in the sera and bronchoalveolar lavage (BAL) fluids of mice infected intranasally with B. pertussis. The results of this study showed that in vitro murine peritoneal macrophages induce production of NO in response to B. pertussis and PT. In addition, murine macrophage cell line, J774A.1 also induces NO production after stimulation with B. pertussis. NO production was also detected in alveolar macrophages from mice infected intranasally with B. pertussis. Finally, a significant increment of circulating levels of NO was noted, in the sera but not in the BAL fluids, of mice infected intranasally with B. pertussis.

Nevirapine or Efavirenz Combined with Two Nucleoside Reverse Transcriptase Inhibitors Compared to HAART: A Meta-Analysis of Randomized Clinical Trials

Abstract Purpose: A meta-analysis of randomized controlled trials (RCTs) was performed to evaluate effectiveness and tolerability of triple antiretroviral therapy regimens in HIV-infected patients. Method: RCTs including the nonnucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine (NVP) or efavirenz (EFV) compared to two nucleoside reverse transcriptase inhibitor (NRTI) regimens and to three-drug regimens based on two NRTIs and one protease inhibitor (PI; highly active antiretroviral therapy [HAART]) were analyzed by Peto’s method. Results: A significant virological response was observed in patients treated with NNRTIs (odds ratio [OR] 3.6; 95% CI, 2.2-6.0), particularly in naïve patients (OR 7.4; 95% CI, 4.1-13.5). A fair reduction of HIV disease progression was also observed in patients treated with NNRTIs (OR 0.8; 95% CI, 0.6-1.0). Moreover, a significantly lower rate of HIV progression was observed in patients with a CD4 + lymphocyte count below 100/mm3. Five RCTs comparing two NRTIs and one NNRTI to HAART were subsequently evaluated. A slightly higher rate of virological response was observed with NNRTIs (OR 1.6; 95% CI, 1.1-2.1), whereas no difference was observed concerning progression of HIV disease. Conclusion: Antiretroviral therapy including NVP or EFV was more effective in reducing viral load than therapy with only two NRTIs and was slightly more effective than HAART. Effectiveness in delaying HIV disease progression was less evident, even though lower rate of progression was observed in patients with advanced HIV infection compared to two NRTIs alone.

Circulating levels of FAS/APO-1 in patients with the systemic inflammatory response syndrome

Resolution of inflammation/infection involves removal of neutrophils and other inflammatory cells by the induction of apoptosis. Fas/Apo-1 is a widely occurring apoptotic signal receptor molecule expressed by almost any type of cell, which is also released in a soluble circulating form. In this study we investigated the role of circulating Fas/Apo-1 in patients with systemic inflammatory response syndrome (SIRS). We evaluated 57 critically ill patients, 34 with infectious SIRS (sepsis and septic shock), and 23 patients with noninfectious SIRS. Circulating Fas/Apo-1 was determined by a commercially available immunoassay. Our results clearly show that levels of Fas/Apo-1 were significantly elevated in patients with infectious and noninfectious SIRS (10.4 +/- 8.1 pg/mL, controls: 5.0 +/- 0.7 pg/mL; p < 0.0001). In addition, Fas/Apo-1 levels were not able in predicting in predicting poor outcome of patients with SIRS. In conclusion, these results show that increased levels of Fas/Apo-1 from patients with SIRS is a mechanism which contribute to inflammatory response through accumulation of neutrophils at sites of inflammation/infection.

Circulating levels of granulocyte macrophage colony-stimulating factor in patients with the systemic inflammatory response syndrome.

OBJECTIVES Granulocyte-macrophage colony stimulating factor (GM-CSF) is a key regulator cytokine that modulates the proliferation and maturation of polymorphonuclear and mononuclear progenitors. This study was designed to investigate and clarify the role of GM-CSF in 52 critically ill patients with systemic inflammatory response syndrome (SIRS). METHODS Serum levels of GM-CSF were detected by an immunoenzyme assay. RESULTS Our results clearly show that the serum concentrations of GM-CSF were significantly elevated in patients with infectious and noninfectious SIRS (33.2+/-45.7pg/ml, controls: 17.2+/-9.8pg/ml; p=0.0303). In addition, GM-CSF levels significantly decreased in patients with SIRS, particularly in patients with infectious SIRS, 5 and 7 days later. There was a clear tendency toward higher levels of GM-CSF in patients with poor, as compared with those having a good outcome of the disease. CONCLUSION These results show that GM-CSF may play an important role in patients with infectious and noninfectious SIRS, and that GM-CSF levels progressively and significantly decrease in patients with infectious SIRS.

A retrospective study on the efficacy and safety of amphotericin B in a lipid emulsion for the treatment of cryptococcal meningitis in AIDS patients

To evaluate the efficacy and safety of Amphotericin B dissolved in dextrose (Amb) or in a lipid emulsion (Intralipid, Amb-IL) in AIDS patients with cryptococcal meningitis, we conducted a retrospective study in 30 AIDS patients with cryptococcal meningitis. A clinical complete resolution was obtained in 11 patients (55%) treated with Amb, and in six patients (60%) treated with Amb-IL. Intralipid did not decrease the infusion-related adverse effects, in particular nephrotoxicity and anaemia. Our results indicate that Amb-IL formulation is useful in the treatment of cryptococcal meningitis in AIDS patients, but it does not reduce the infusion-related adverse events.

Levels of the bcl-2 protein, fibronectin and α5β1 fibronectin receptor in HIV-1-infected patients with Kaposi's sarcoma.

Abstract Kaposis sarcoma (KS) is an angioproliferative disease characterized by proliferation of neoplastic cells (spindle cells) mixed with endothelial and inflammatory cells. In this study we evaluated the role of the adhesive glycoprotein, fibronectin (FN) and its receptor α 5 β 1 (FNR), and the proto-oncogene bcl-2, an anti-apoptotic protein. Significantly decreased serum levels of FN were noted in HIV-1-infected patients with KS, whereas serum levels of FNR were significantly increased in the same patients. Furthermore, increased FNR expression was observed on CD4 cells from KS patients. Serum levels of bcl-2 protein were significantly decreased in asymptomatic seropositive patients, whereas HIV-1-infected patients with KS showed increased serum levels of bcl-2. These results provide further information about interaction between integrins and the extracellular matrix and bcl-2 protein that can support cell survival either of neoplastic cells or endothelial and inflammatory cells.