Effect of ceftazidime/avibactam plus fosfomycin combination on 30†day mortality in patients with bloodstream infections caused by KPC-producing Klebsiella pneumoniae: results from a multicentre retrospective study.

Introduction: The primary outcome of the study was to evaluate the effect on 30 day mortality of the combination ceftazidime/avibactam + fosfomycin in the treatment of bloodstream infections (BSIs) caused by KPC-producing Klebsiella pneumoniae (KPC-Kp). Materials and methods: From October 2018 to March 2021, a retrospective, two-centre study was performed on patients with KPC-Kp BSI hospitalized at Sapienza University (Rome) and ISMETT-IRCCS (Palermo) and treated with ceftazidime/avibactam-containing regimens. A matched cohort (1:1) analysis was performed. Cases were patients receiving ceftazidime/avibactam + fosfomycin and controls were patients receiving ceftazidime/avibactam alone or in combination with in vitro non-active drugs different from fosfomycin (ceftazidime/avibactam ±â€Šother). Patients were matched for age, Charlson comorbidity index, ward of isolation (ICU or non-ICU), source of infection and severity of BSI, expressed as INCREMENT carbapenemase-producing Enterobacteriaceae (CPE) score. Results: Overall, 221 patients were included in the study. Following the 1:1 match, 122 subjects were retrieved: 61 cases (ceftazidime/avibactam + fosfomycin) and 61 controls (ceftazidime/avibactam ±â€Šother). No difference in overall mortality emerged between cases and controls, whereas controls had more non-BSI KPC-Kp infections and a higher number of deaths attributable to secondary infections. Almost half of ceftazidime/avibactam + fosfomycin patients were prescribed fosfomycin without MIC fosfomycin availability. No difference in the outcome emerged after stratification for fosfomycin susceptibility availability and dosage. SARS-CoV-2 infection and ICS ≥ 8 independently predicted 30 day mortality, whereas an appropriate definitive therapy was protective. Conclusions: Our data show that fosfomycin was used in the treatment of KPC-Kp BSI independently from having its susceptibility testing available. Although no difference was found in 30 day overall mortality, ceftazidime/avibactam + fosfomycin was associated with a lower rate of subsequent KPC-Kp infections and secondary infections than other ceftazidime/avibactam-based regimens.

Retroperitoneal approach for robot-assisted partial nephrectomy: technique and early outcomes

ABSTRACT Objectives The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy). Materials and methods From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded. Results All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7). Conclusions The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.

Retroperitoneal approach for robot-assisted partial nephrectomy: technique and early outcomes.

OBJECTIVES: The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy). MATERIALS AND METHODS: From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded. RESULTS: All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7). CONCLUSIONS: The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.

Multi-functional flow cytometry analysis of CD4+ T cells as an immune biomarker for latent tuberculosis status in patients treated with tumour necrosis factor (TNF) antagonists.

Although monitoring tuberculosis (TB) infection during long-term treatment with tumour necrosis factor (TNF) antagonists is of great importance, no monitoring strategy has yet proved successful. Indeed, even the newly proposed interferon-gamma release assays (IGRAs) are known to produce dynamic changes in IFN-γ plasma levels, making them unreliable indicators of patients' pathological/clinical status. We used intracellular cytokine flow cytometry (ICCFC) to investigate the performance of multi-functional CD4(+) T cells producing IFN-γ, interleukin (IL)-2 and/or TNF in response to Mycobacterium tuberculosis-specific antigens in subjects treated with TNF antagonists. Patients were classified into three groups based on their TB status before commencement of treatment and on IFN-γ level fluctuations evaluated by IGRA during a 36-month follow-up period. The cytokine profile of M. tuberculosis-specific CD4(+) T cells showed that latent tuberculosis infection (LTBI) subjects had a higher frequency of double-positive IFN-γ(+) IL-2(+) CD4(+) T cells and triple-positive IFN-γ(+) IL-2(+) TNF(+) CD4(+) T cells compared to those without LTBI, who showed IFN-γ-level fluctuations over time. In contrast, this latter group of patients showed similar proportions of cells producing IFN-γ alone, IL-2 alone and IL-2 in combination with TNF in response to M. tuberculosis-specific antigens. It therefore appears that patients with and without LTBI infection are characterized by different intracellular cytokine profiles. This is the first study evaluating ICCFC in patients treated with TNF antagonists, and suggests that multi-functional analysis of CD4(+) T cells could be useful for ruling out TB infection in patients classified at screening as LTBI-negative but who show IGRA fluctuations under long-term TNF antagonist treatment.

Interferon-γ release assay for tuberculosis in patients with psoriasis treated with tumour necrosis factor antagonists: in vivo and in vitro analysis.

BACKGROUND: Screening for latent tuberculosis infection (LTBI) is mandatory in patients with psoriasis prior to starting on tumour necrosis factor (TNF) blockers. OBJECTIVES: To investigate the longitudinal changes of interferon (IFN)-γ response to Mycobacterium tuberculosis-specific antigens by serial QuantiFERON-TB Gold In-Tube (QFT-GIT) testing in patients with psoriasis during long-term anti-TNF therapy. The direct in vitro effect of adalimumab on IFN-γ secretion was also evaluated. METHODS: In total, 148 patients with psoriasis designated to start anti-TNF treatment were enrolled. We performed a tuberculin skin test at screening, and QFT-GIT at baseline and serially for 24 months after TNF antagonist onset. RESULTS: At screening, QFT-GIT was positive in 22.3% of the patients, negative in 73.6% and indeterminate in 4%. The IFN-γ response following isoniazid therapy declined and became QFT-GIT negative in 8% of 26 patients with LTBI; in 69% of subjects with LTBI the QFT-GIT remained persistently positive with a significant increase of IFN-γ levels during the follow-up, even if no cases of active tuberculosis were found. Variations of IFN-γ levels were observed also in 7% of 27 patients without LTBI who switched to positive QFT-GIT after 12 or 18 months of biologic therapy, suggesting a new occurrence or reactivation of LTBI. In vitro data showed that in the presence of adalimumab the IFN-γ levels were significantly reduced in a dose-dependent manner (P < 0.05). CONCLUSIONS: Fluctuations of IFN-γ release may occur in patients with psoriasis treated with TNF antagonists. The clinical use of repeated blood tests and the correct interpretation of individual IFN-γ changes could be useful in identifying possible cases of LTBI reactivation or newly acquired tuberculosis infection during long-term anti-TNF treatment.

Study of methicillin-resistant Staphylococcus aureus (MRSA) carriage in a population of HIV-negative migrants and HIV-infected patients attending an outpatient clinic in Rome.

BACKGROUND: Migration and HIV infection are known risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage and infection. The aim of the study was to analyze the prevalence of MRSA nasal colonization in a high risk population of HIV-negative migrants and HIV-infected subjects. Secondary aim was to investigate over time MRSA carriage prevalence in HIV-infected subjects. METHODS: During the study period (January-June 2008), nasal swabs were collected from 96 HIV-negative migrants and 63 HIV-infected patients. A group of 68 seropositive subjects was additionally screened for MRSA carriage in 2012. Subjects were evaluated for HIV status, previous antibiotic use or hospitalization, soft tissue and skin infections (SSI), nationality and work conditions. The swab specimens were plated and incubated for 24-h under static condition at 37 degrees and then identified as S. aureus by using standard methods. RESULTS: A total of 227 subjects, 131 HIV-infected adults (63 in 2008 and 68 in 2012) and 96 HIV-negative migrants, were analyzed. Overall, 71/227 (31.2%) were S. aureus carriers: 34 out of 131 (25.9%) among HIV infected subjects and 37 out of 96 (38.5%) among migrants. Two MRSA were detected in HIV-infected patients (2.8%). Between 2008 and 2012 there was an increase of MRSA carriage in HIV+ group (p=0.49). No statistically significant differences were found between S. aureus carriers and no-carriers in terms of CD4+ cell count, TMP/SMX prophylaxis, previous antibiotic use or hospitalization, nationality and duration of stay in Italy. Among HIV+ patients there was a higher prevalence of SSI in MSSA carriers compared with no carriers (25% vs 4%, p=0.028). In the migrants group, having a job based on a close human contact was significantly associated with S. aureus colonization (p=0.0038). CONCLUSIONS: Despite of the high prevalence of S. aureus isolation (31.2%), the present study showed the low rate of MRSA carriage in a high risk population. The main factor associated with S. aureus colonization was a close human contact rather than the HIV status and the condition of being migrant.

In vitro effect of anti-human immunodeficiency virus CCR5 antagonist maraviroc on chemotactic activity of monocytes, macrophages and dendritic cells.

Compounds targeting the chemokine receptor CCR5 have recently been approved for treatment of human immunodeficiency virus (HIV) infection. Given the central role of CCR5 in inflammation and recruitment of antigen-presenting cells (APC), it is important to investigate the immunological consequences of pharmacological inhibition of CCR5. We evaluated the in vitro effect of different concentrations of CCR5 antagonist maraviroc (MVC) on cell migration of monocytes, macrophages (MO) and monocyte-derived dendritic cells (MDC) towards peptide formyl-methionyl-leucyl-phenylalanine (fMLP) and chemokines regulated upon activation normal T cell expressed and secreted (RANTES) and CCL4/macrophage inflammatory protein-1 (MIP-1ß) and CCL2/monocyte chemotactic protein-1 (MCP-1). Results of flow cytometric analysis showed that monocytes treated in vitro with MVC exhibited a significant dose-dependent reduction of chemotaxis towards MIP-1ß and MCP-1. fMLP-induced chemotactic activity decreased only at higher concentration (1 µM and 10 µM of MVC). In addition, all concentrations of MVC (0·1, 1 and 10 µM) induced in vitro a significant inhibition of chemotaxis of MO and MDC in response to all tested chemoattractants. No change in phenotype (CD1a and CD14) and CCR1, CCR4, CCR5 and formyl peptide receptor (FPR) expression was seen after in vitro treatment with MVC. These findings suggest that CCR5 antagonist MVC may have the in vitro ability of inhibiting the migration of innate immune cells by mechanism which could be independent from the pure anti-HIV effect. The drug might have a potential role in the down-regulation of HIV-associated chronic inflammation by blocking the recirculation and trafficking of MO and MDC.

Evaluation of QuantiFERON-TB Gold In-Tube in human immunodeficiency virus infection and in patient candidates for anti-tumour necrosis factor-alpha treatment.

SETTING: Cross-sectional study at four out-patient clinics in a single referral centre in Italy. OBJECTIVE: To evaluate the performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) in human immunodeficiency virus (HIV) infected adults and in patients with immune-mediated inflammatory diseases (IMIDs) who are candidates for anti-tumour necrosis factor-alpha (TNF-alpha) treatment. DESIGN: A total of 402 immunocompromised patients were enrolled, including 207 HIV-infected individuals and 195 IMID patients scheduled for anti-TNF-alpha treatment. Tuberculin skin test (TST) and QFT-GIT were performed. For active tuberculosis (TB), test results were compared with microbiological, histopathological and clinical diagnoses. RESULTS: In HIV-infected patients, the level of agreement between the tests was 68% and QFT-GIT sensitivity was 66% (95%CI 47-82). We found a large proportion of indeterminate QFT-GIT results (33.4%), which correlated with CD4 count < 200 cells/microl (P < 0.0001). The degree of agreement with TST was higher in IMID patients (81.6%). Factors associated with discordant positive TST and negative QFT-GIT results were bacille Calmette-Guérin vaccination (P = 0.0001), previous TB (P = 0.0001) and agricultural work (P = 0.0005). CONCLUSION: The performance of QFT-GIT varies between different types of immunocompromised patients. Interferon-gamma release assays should not be used to confirm or rule out a diagnosis of active TB in HIV-infected adults. As there were no cases of active TB in the IMID subgroup, it was difficult to determine which test performs better in this population.

Detection of interleukin-2 in addition to interferon-gamma discriminates active tuberculosis patients, latently infected individuals, and controls.

Effective control of tuberculosis (TB) includes discrimination of subjects with active TB from individuals with latent TB infection (LTBI). As distinct interferon (IFN)-gamma and interleukin (IL)-2 profiles of antigen-specific T-cells have been associated with different clinical stages and antigen loads in several viral and bacterial diseases, we analysed these cytokines in TB using a modified QuantiFERON-TB Gold In Tube test. Detection of IL-2 in addition to IFN-gamma distinguishes not only Mycobacterium tuberculosis-infected subjects from healthy controls, but also individuals with LTBI from active TB patients. This may help to improve diagnostic tests for TB.

Inhibitory activity of Melissa officinalis L. extract on Herpes simplex virus type 2 replication.

Melissa officinalis L. (Lamiaceae) (lemon balm) is used in folk medicine for nervous complaints, lower abdominal disorders and, more recently, for treating Herpes simplex lesions. In this work the antiviral activity of a hydroalcoholic extract of lemon balm leaves against the Herpes simplex virus type 2 (HSV-2) was assessed by the cytopathic effect inhibition assay on Vero cells (ATCC CCL-81), in comparison with acyclovir. The cytotoxicity of the extract on Vero cells was previously tested by evaluating the cellular death and was confirmed by the Trypan blue test. Lemon balm showed to reduce the cytopathic effect of HSV-2 on Vero cells, in the range of non-toxic concentrations of 0.025-1 mg mL(-1) (with reference to the starting crude herbal material). The maximum inhibiting effect (60%) was obtained with 0.5 mg mL(-1). The viral binding assay showed that the extract does not prevent the entry of HSV-2 in the cells, thus suggesting a mechanism of action subsequent to the penetration of the virus in the cell. The extract was also chemically characterised by NMR and HPLC analysis; it showed to contain cinnamic acid-like compounds, mainly rosmarinic acid (4.1% w/w). Our experiments support the use of lemon balm for treating Herpes simplex lesions and encourage clinical trials on this medicinal plant.

[The use of bipolar PlasmaKinetic resectoscope in endoscopic resection of the prostate: our experience].

Prostatic endoscopic resection (TURP) is a reference method in the treatment of prostatic obstruction. In the past decades, the method used a monopolar resectoscope. In the last years, various technologies have been studied to improve the efficacy of endoscopic resection. As per our experience, we have thence ascertained the variations of the hematic crasis and of the mictional asset in TURP patients treated with bipolar knives. 20 patients underwent bipolar plasmakinetic resection of the prostate. Their age ranged between 58 yrs and 82 yrs (av.: 70.2 yrs), the adenoma volume, checked with TR ultrasound scanning, was between 33 and 44 cc (av.: 37.6), the Qmax was between 6.4 and 9.0 mL/min (av.: 7.42 mL/min). A 24Ch resectoscope and spinal anesthesia were used. Bleeding during resection was never relevant; therefore resection never had to be stopped. After about 36 hours from surgery, the patients' sanguification was checked again: a 6.53% reduction of the number of erythrocytes, compared to pre-surgery data, was observed, together with a 6.73% decrease of hemoglobin concentration, and a 6.3% decrease of hematocrit. Continuous irrigation was suspended during the first day, catheter was removed on the 48th hour in 15 cases, and on the 72nd in 5 cases: the patients were discharged on day 3 in 16 cases, and on day 4 in 4 cases. A flux evaluation was performed after 3 months, which showed a Qmax between 16.6 and 24 mL/min (av.: 19.11), with a significant increase in the maximum flow rate. The use of the new technologies in prostatic endoscopic resection has allowed us to improve the efficacy of such a method. Above all, the use of a bipolar electrosurgical knife enables us to associate a basal hemostasis with the resection of the prostatic tissue. Thus, the hematic loss is low, as we have been able to ascertain also in our own experience. This gave us the possibility to quickly stop continuous irrigation and to early remove the catheter. This way, hospitalization was sensibly reduced (av. 76.8 hours). The maximum flow rate, in the short term, has been good. We have been able, in our experience, to assess that this technology represents a useful guarantee to improve the results of prostatic endoscopic resection.

HIV protease inhibitor therapy reverses neutrophil apoptosis in AIDS patients by direct calpain inhibition.

The reduction of neutrophils apoptosis is one of the main non-virological effects of protease inhibitor (PI) therapy. We explore here whether this may be due to the cross-inhibition of calpain, an important non-virological target of PI in vitro. We found that the high basal level of neutrophils apoptosis in AIDS patients is strictly related to an increased intracellular calpain activity. Both alterations disappear after PI treatment, with apoptosis and calpain going back to normal levels after 3 months of PI therapy, independently of a proficient antiviral effect. PI drugs exerted a similar antiapoptotic and anticalpain effects on neutrophils in ex vivo experiments: strikingly, the effects were mimicked by commercially available calpain inhibitors. This study shows, for the first time, that apoptosis of neutrophils in AIDS patients is mediated by calpain, and that neutrophil survival in PI treated AIDS patients is a non virological effect due to calpain inhibition.

Circulating dendritic cells and interferon-alpha production in patients with tuberculosis: correlation with clinical outcome and treatment response.

Dendritic cells (DC) have been characterized recently as having an important role in the initiation and control of immunological response to Mycobacterium tuberculosis infection. Blood DC have been subdivided into myeloid (mDC) and plasmacytoid (pDC) subsets, on the basis of differences in phenotype markers and function. Little is known about the enumeration and functional evaluation of circulating DC in patients with tuberculosis and their correlation with clinical outcome during the course of anti-tuberculous treatment. We assessed circulating mDC and pDC counts measured by a newly developed single-platform flow cytometric assay based on TruCOUNT, as well as the production of interferon (IFN)-alpha after in vitro stimulation by herpes simplex virus (HSV-1) in 24 patients with active tuberculosis (TB) and 37 healthy donors. Absolute numbers of both DC subsets were decreased significantly in patients with active TB compared to controls. Similarly, the production of IFN-alpha was highly impaired. In 13 patients these parameters were assessed longitudinally, before and after the specific anti-microbial treatment. Most interestingly, in all nine patients with successful anti-tuberculous therapy there was a significant and marked increase of pDC counts and IFN-alpha production. In contrast, no significant longitudinal variations in DC counts and IFN-alpha production were observed in four patients with lack of response to specific treatment. In conclusion, active TB is associated with a defect in blood DC numbers and IFN-alpha production that is restored after bacterial clearance and clinical improvement, as a result of effective anti-tuberculous treatment.

Anti-HIV drugs decrease the expression of matrix metalloproteinases in astrocytes and microglia.

The introduction of potent antiretroviral drugs for the treatment of patients with human immunodeficiency virus (HIV) infection has dramatically reduced the prevalence of HIV-associated neurological disorders. Such diseases can be mediated by proteolytic enzymes, i.e. matrix metalloproteinases (MMPs) and, in particular gelatinases, released from glial cells. The aim of this study was to investigate whether the antiretroviral drugs commonly used for the treatment of HIV-infected patients modulate the activity of MMPs in astrocyte and microglial cultures. Primary cultures of rat astrocyte and microglia were treated with different doses of zidovudine (AZT) or indinavir (IDV) for 20 h and simultaneously activated by exposure to lipopolysaccharide (LPS). Culture supernatants collected from astrocytes and microglia after 24 h incubation were subjected to gelatin zymography and western blot analysis for the assessment of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) protein levels. Total RNA was extracted from glial cells and used for reverse transcriptase-polymerase chain reaction for the assessment of mRNA expression. Our results indicate that both astrocyte and microglial cells constitutively express MMP-2 mRNA and protein. LPS treatment increased MMP-2 mRNA and protein expression in astrocytes, but not in microglial cells. The treatment with both AZT and IDV dose-dependently inhibited the expression of MMP-2 in astrocytes, whereas it had no effect on microglial cells. The expression of MMP-9 in both astrocytes and microglia was induced by LPS treatment and was dose-dependently inhibited by AZT and IDV treatment in LPS-stimulated astrocytes and microglia. These results raise the possibility that AZT and IDV interfere directly with MMP production in glial cells and independently from their antiviral activity, thus suggesting the possible therapeutical use in neurological diseases associated with MMPs involvement.

Circulating levels of interleukin-7 in antiretroviral-naïve and highly active antiretroviral therapy-treated HIV-infected patients.

UNLABELLED: Interleukin (IL)-7 is a critical cytokine regulating T-lymphocyte development, regeneration, and function. PURPOSE: This study analyzes the endogenous IL-7 production in HIV-infected patients receiving highly active antiretroviral treatment (HAART). METHOD: Plasma levels of IL-7 were measured by enzyme-linked immunosorbent assay (ELISA) in 11 patients with untreated advanced HIV disease, in 8 patients who successfully responded to HAART, and in 9 individuals with virological and immunological treatment failure. RESULTS: We found that in the patients with advanced HIV disease and no treatment IL-7 concentrations were elevated and were inversely related to both CD4 + and CD8 + T-cell counts. When IL-7 was assessed in treated patients, this cytokine was below the detection limit of the assay in all participants who responded to HAART. On the contrary, patients with evidence of HAART failure had increased concentrations of IL-7 that were comparable to those found in the untreated group with progressive disease. CONCLUSION: These data suggest that IL-7 may play a role in the immune reconstitution of T-cells during HIV infection, especially in the context of potent antiretroviral treatments.

Ex vivo and in vitro effect of human immunodeficiency virus protease inhibitors on neutrophil apoptosis.

Polymorphonuclear leukocytes (PMNL) from human immunodeficiency virus (HIV)-infected patients exhibit accelerated apoptosis and impaired functional activity. HIV protease inhibitor-based therapy produces improvements in both acquired and innate immune responses. Ex vivo and in vitro effects of HIV protease inhibitors on apoptosis and chemotaxis of PMNL were evaluated. After therapy, there was a rapid and significant decrease of PMNL apoptosis, which correlated with increased chemotactic function. These findings were found both in patients with immunological and virological response and in control subjects who showed an increase in CD4(+) T cell counts but no concomitant decline in HIV load. After in vitro treatment with ritonavir or indinavir, apoptosis of both HIV-infected and -uninfected PMNL markedly decreased and correlated with significant enhancement of chemotaxis. These results suggest that HIV protease inhibitors may improve the PMNL function by reducing the apoptosis rate and that this effect may, at least in part, be independent of their antiviral activity.

Interleukin-15 enhances neutrophil functional activity in patients with human immunodeficiency virus infection.

Polymorphonuclear leukocyte (PMN) dysfunction has been reported in human immunodeficiency virus (HIV)-infected patients. Interleukin (IL)-15 is a recently discovered cytokine that potentiates antimicrobial functions of normal PMNs. We evaluated the in vitro effect of IL-15 on chemotaxis and fungicidal activity of PMNs from 9 patients with untreated advanced HIV infection, 8 patients with viral suppression after 52 to 130 weeks of highly active antiretroviral therapy (HAART), and 12 patients with treatment failure. We also studied oxidative burst and apoptosis of PMNs in 5 patients with untreated advanced HIV infection. Twelve healthy donors were included as controls. Chemotaxis and fungicidal activity of unprimed PMNs was significantly lower in patients with untreated HIV infection compared with controls. After incubation with IL-15, a significant increase in PMN chemotaxis and fungicidal activity was found; moreover, IL-15 induced a significant reduction in the number of apoptotic HIV(+) PMNs. IL-15 did not modulate oxidative burst of HIV(+) PMNs as measured by chemiluminescence production. The in vitro priming of PMNs with IL-15 determined a complete reversal of defective chemotaxis and killing in all HAART-treated patients with long-term HIV suppression. IL-15 significantly enhanced chemotaxis and fungicidal activity also in patients with HAART failure. In conclusion, IL-15 is an important cytokine in the activation of the functional properties of HIV(+) PMNs, by delaying apoptosis and enhancing chemotaxis and fungicidal activity. The potent stimulant effect of IL-15 on PMN function was observed in antiretroviral naive patients as well as in individuals who were receiving HAART, including those with treatment failure. (Blood. 2000;96:1979-1984)

Changes in circulating levels of soluble cell adhesion molecules following highly active antiretroviral treatment of HIV-1-infected patients.

Increased levels of soluble cell adhesion molecules (sCAM) have been reported in HIV-1 infection and may possibly contribute to altering the adhesion mechanisms of phagocytic cells. We evaluated the effect of highly active antiretroviral therapy (HAART) on plasma levels of sL-selectin, sE-selectin, intercellular cell adhesion molecule-1 (sICAM-1), sICAM-3, and vascular cell adhesion molecule-1 (sVCAM-1). Study participants included 22 HIV-1-infected patients with a CD4+ T-cell count/microl below 500 who were started on a HAART regimen and followed up for 9 months. After the initiation of therapy, plasma sL-selectin concentrations progressively decreased to normal ranges in the majority of our patients (P < 0.001), while no changes in sE-selectin were found. In all patients sICAM-1 remained relatively constant at significantly elevated concentrations during the 9 months of therapy. A significant reduction in plasma concentrations of both sICAM-3 and sVCAM-1 was found; however, the levels of these sCAM were not normalized by HAART and remained significantly elevated throughout the study (P < 0.001). The reduced release of sL-selectin could improve the ability of phagocitic cells to migrate in response to chemotactic stimuli after starting HAART. On the other hand, the persistent elevation of sICAM-1, sICAM-3, and sVCAM-1 could reflect continuous HIV-1-mediated immune activation, despite adequate control of plasma HIV-1 replication by therapy.

Search for an antibody profile of Rhodococcus equi infection in AIDS patients despite the diversity of isolates and patient immune dysfunction.

Diversity of virulence-associated antigens of Rhodococcus equi was detected among thirteen strains isolated from AIDS patients on two continents. One out of four Brazilian isolates presented the virulence-associated antigen of 15- to 17-kDa, and the other three isolates had the 20-kDa virulence-associated antigen. In contrast, only three out of nine Italian isolates were positive for virulence-associated antigens - two for the 15- to 17-kDa antigen and one for the 20-kDa antigen. In four other Italian strains, one or more other low-molecular-weight antigens were identified. Because of R. equi variability and host immune dysfunction, no characteristic antibody profile was detected among patients, although the presence of specific antibodies in serum samples suggested prognostic value: good patient outcome and recovery from pneumonia were correlated with R. equi antibody detection, whereas the lack or disappearance of specific antibodies, mainly those to low-molecular-weight antigens, was correlated with disease progression and patient death. These results confirmed the nonobligatory presence of the well-known virulence-associated antigens for the pathogenicity of R. equi in humans, and also the diversity of R. equi strains isolated from AIDS patients, which may be related to the geographic origin of the isolates or may be a consequence of the route of R. equi transmission in different countries. Some mechanisms underlying the results obtained are discussed, suggesting immune complex formation during the progress of the disease.

Improvement in neutrophil and monocyte function during highly active antiretroviral treatment of HIV-1-infected patients.

OBJECTIVE: To investigate the effect of highly active antiretroviral treatment (HAART) on neutrophil and monocyte function in patients with moderately advanced HIV-1 infection. DESIGN: Eighteen HIV-1-infected patients with CD4 T cell counts below 350/microl, no concomitant active infection, and no previous use of protease inhibitors were treated with indinavir or ritonavir and two reverse-transcriptase inhibitors and were followed up for 9 months. Ten age- and sex-matched healthy subjects were included as controls. METHODS: The functional activity of neutrophils and monocytes was measured by assessing chemotaxis towards a bacterial peptide, killing activity against Candida albicans, and oxidative burst as measured by chemiluminescence production. RESULTS: Neutrophils and monocytes from the treatment group exhibited a significantly diminished baseline chemotactic and fungicidal activity compared with healthy controls (P < 0.001). After starting HAART, there was a significant improvement in chemotaxis and fungicidal activity of phagocytic cells (P < 0.001). Values of chemotaxis reached normal ranges in 13 out of 18 patients (72%) for neutrophils and eight out of 18 (44%) for monocytes, whereas phagocyte killing was rarely restored to normal values (3/18 cases for monocytes and 0/18 for neutrophils). The administration of HAART was also associated with significantly increased phagocyte chemiluminescence production in response to phorbol-12-myristate 13-acetate or opsonized C. albicans (P < 0.01). CONCLUSION: The functional improvement of two critical components of innate antimicrobial immunity, such as neutrophils and monocytes, may contribute to the improved cell-mediated immune responses against opportunistic infections in HAART-treated patients.