Extended and Continuous Infusion of Novel Protected β-Lactam Antibiotics: A Narrative Review

Consolidated data from pharmacokinetic and pharmacodynamic studies support the administration of β-lactam antibiotics in prolonged infusion (i.e., extended or continuous) to optimize therapeutic efficacy by increasing the probability of attaining maximal bactericidal activity. This is the longest possible time during which the free drug concentrations are approximately four-fold the minimum inhibitory concentration between dosing intervals. In the context of antimicrobial stewardship strategies, achieving aggressive pharmacokinetic and pharmacodynamic targets is an important tool in the management of multi-drug resistant (MDR) bacterial infections and in the attainment of mutant preventing concentrations. However, prolonged infusion remains an unexploited resource. Novel β-lactam/β-lactamase inhibitor (βL/βLI) combinations (ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-cilastatin-relebactam) have been released in recent years to face the emerging challenge of MDR Gram-negative bacteria. Pre-clinical and real-life evidence has confirmed the promising role of prolonged infusion of these molecules in specific settings and clinical populations. In this narrative review we have summarized available pharmacological and clinical data, future perspectives, and current limitations of prolonged infusion of the novel protected β-lactams, their application in hospital settings and in the context of outpatient parenteral antimicrobial therapy.

Low cerebrospinal fluid Amyloid-βeta 1-42 in patients with tuberculous meningitis

BACKGROUND

Tuberculous meningitis (TBM) is an important disease leading to morbidity, disability and mortality that primarily affects children and immune-depressed patients. Specific neuromarkers predicting outcomes, severity and inflammatory response are still lacking. In recent years an increasing number of evidences show a possible role for infective agents in developing neurodegenerative diseases.

METHODS

We retrospectively included 13 HIV-negative patients presenting with TBM and we compared them with two control groups: one of patients with a confirmed diagnosis of AD, and one of those with syphilis where lumbar punctures excluded central nervous system involvement. Lumbar punctures were performed for clinical reasons and CSF biomarkers were routinely available: we analyzed blood brain barrier permeability (CSF to serum albumin ratio, "CSAR"), intrathecal IgG synthesis, (CSF to serum IgG ratio), inflammation (neopterin), amyloid deposition (Aβ1-42), neuronal damage (T-tau, P-tau, 14.3.3) and astrocytosis (S-100 β).

RESULTS

TBM patients were 83 % male and 67 % Caucasian with a median age of 51 years (24.5-63.5 IQR). Apart from altered CSAR (median value 18.4, 17.1-30.9 IQR), neopterin (14.3 ng/ml, 9.7-18.8) and IgG ratios (15.4, 7.9-24.9), patients showed very low levels of Aβ1-42 in their CSF (348.5 pg/mL,125-532.2), even lower compared to AD and controls [603 pg/mL (IQR 528-797) and 978 (IQR 789-1178)]. Protein 14.3.3 tested altered in 38.5 % cases. T-tau, P-tau and S100Beta were in the range of normality. Altered low level of Aβ1-42 correlated over time with classical TBM findings and altered neuromarkers.

CONCLUSIONS

CSF Biomarkers from patients with TBM were compatible with inflammation, blood brain barrier damage and impairment in amyloid-beta metabolism. Amyloid-beta could be tested as a prognostic markers, backing the routine use of available neuromarkers. To our knowledge this is the first case showing such low levels of Aβ1-42 in TBM; its accumulation, drove by neuroinflammation related to infections, can be central in understanding neurodegenerative diseases.

Early low-molecular-weight heparin administration is associated with shorter time to SARS-CoV-2 swab negativity

BACKGROUND

Antiviral and immune-modulating properties of low-molecular-weight heparin (LMWH) against Coronaviridae have been reported by in vitro studies, but no in vivo evidence is yet available. We sought to know whether the timing of prophylactic doses of LMWH during the course of COVID-19 may affect the time to SARS-CoV-2 nasal-oropharyngeal swab negativization.

METHODS

Retrospective monocentric cross-sectional study on patients requiring sub-intensive ward admission due to first SARS-CoV-2 infection and undergoing early (EH; within 7 days from COVID-19 signs and symptoms onset) versus delayed prophylactic LMWH (DH; after 7 days). SARS-CoV-2 RNA was measured by reverse transcription real-time PCR according to scheduled time points: first swab after 2 weeks from COVID-19 onset, then at 1-week intervals until negativity.

RESULTS

Time to SARS-CoV-2 swab negativity was shorter in EH (38 patients) compared with DH (55 patients): 22 versus 37 days (P=0.004). The number of confirmative negative swabs in EH was significantly higher compared with DH at week 2 (21.1% versus 3.6%; P=0.017) and 4 (60.0% versus 19.6%; P<0.001). At univariate, EH differed from DH for several disease severity and clinical management parameters. Nevertheless, after accounting for the differences, Cox regression showed early LMWH administration (hazard ratio [HR] 2.91 [1.51, 5.63]; P=0.002) and higher lymphocytes nadir (HR 1.04 [1.01, 1.08]; P=0.020) as predictors of shorter time to swab negativity.

CONCLUSIONS

This potential antiviral and/or immune-modulating activity of LMWH needs further in vivo confirmations by randomized controlled trials.

Risk for SARS-CoV-2 Infection in Healthcare Workers, Turin, Italy

We measured severe acute respiratory syndrome coronavirus 2 spike protein subunits S1/S2 antibodies by using capillary electrophoresis and a chemiluminescence immunoassay for 5,444 active healthcare workers in Italy. Seroprevalence was 6.9% and higher among participants having contact with patients. Seroconversion was not observed in 37/213 previously infected participants.

Presence of Epstein-Barr virus DNA in cerebrospinal fluid is associated with greater HIV RNA and inflammation

OBJECTIVE

The current study aimed to investigate whether cerebrospinal fluid (CSF) Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA was associated with viral, inflammatory and neuronal damage biomarkers in people living with HIV (PLWH).

DESIGN

A cross-sectional diagnostic study on CSF fluid samples in patients undergoing lumbar punctures for clinical reasons, to better understand the role of EBV and CMV in the CNS on HIV RNA replication, blood-brain-barrier (BBB) damage and biomarkers of neuronal damage/inflammation.

METHODS

EBV, CMV DNA and HIV RNA were measured on CSF, through real time (RT)-PCR, from PLWHs undergoing lumbar punctures for clinical reasons (excluding oncho-haematological comorbidities). Immune-enzymatic assays evaluated blood-brain barrier inflammation and damage. Patients were stratified according to plasma HIV RNA levels in viremic (≥50 copies/ml) and aviremic (<50 copies/ml).

RESULTS

We included 297 participants. Among 167 viremic patients CSF EBV and CMV DNA were detectable in 42 (25.1%) and 10 (6.3%) participants; among 130 aviremic individuals CSF EBV and CMV DNA were detectable in 12 (9.2%) and 0 (0%) participants, respectively. In viremic group detectable CSF EBV DNA was associated with CSF pleocytosis (P < 0.001), higher CSF HIV RNA (P < 0.001) and neopterin levels (P = 0.002). In aviremic participants detectable EBV DNA was associated with pleocytosis (P = 0.056), higher neopterin (P = 0.027) and immune globulins (P = 0.016) in the CSF; CSF escape was more common in those with detectable EBV DNA (50 vs. 21.2%, P = 0.036).

CONCLUSION

EBV DNA was frequently detected in the CSF of viremic and fewer aviremic patients on antiretroviral treatment. In PLWH without clinical evidence of encephalitis CSF EBV DNA was associated with higher biomarkers levels of neuronal damage/inflammation. The role of EBV reactivation in HIV-associated central nervous system disorders warrants further studies.

The outcome of HIV-positive late presenters according to detectable CMV DNA and anti-CMV treatment

BACKGROUND

HIV late presenters are at high risk of cytomegalovirus (CMV) reactivation and end-organ disease. CMV viraemia has been associated with poor survival but the effect of anti-CMV treatment has not been studied in this setting.

METHODS

HIV-positive patients were included in a retrospective study if presenting with <350 CD4⁺ T-cells/μl and starting an antiretroviral treatment within 3 months of the diagnosis. Primary end point was 5-year survival according to the presence of CMV viraemia, CMV end-organ disease and anti-CMV treatment.

RESULTS

302 patients were included. 157 patients (52%) presented CMV viraemia (CMV-V) and 44 (14.6%) CMV end-organ disease (CMV-EOD). 5-year mortality was higher in CMV-EOD and CMV-V patients than in CMV-negative patients (11.4 versus 9.6 versus 0%; P=0.002). In patients with CMV-V, 5-year mortality was numerically higher in untreated patients (12.9% versus 6.9%; P=0.257) without reaching statistical significance. At univariate analysis the diagnosis of serious opportunistic infections (cryptococcosis, progressive multifocal leukoencephalopathy, lymphoma; P=0.001) and the absence of a negative CMV DNA in the follow-up (P<0.001) were associated with poor outcome. At multivariate analysis HCV coinfection (P=0.016; aOR 6.98, 95% CI 1.50, 32.59), the absence of a negative CMV DNA in the follow-up (P<0.001; aOR 19.40, 95% CI 3.70, 101.64) and marginally the absence of anti-CMV treatment (P=0.052; aOR 4.944, 95% CI 0.99, 24.73) were independent predictors of poor outcome.

CONCLUSIONS

CMV reactivation in HIV-positive patients with poor immunity is associated with worse prognosis: the pre-emptive use of anti-CMV therapy was associated with a better outcome in patients with CMV-V.

The "milky way" galaxy of HIV-related central nervous system immune reaction syndromes

The landscape of central nervous system HIV infection is rapidly changing, leading to the recognition of a new constellation of overlapping syndromes and to a better insight for the elder ones. Among these, progressive multifocal leukoencephalopathy (PML) still poses several diagnostic and therapeutic challenges; nevertheless, recent developments in understanding PML in patients with multiple sclerosis may have benefitted HIV-positive patients suffering from PML too. We describe a peculiar case of PML-immune reconstitution inflammatory syndrome (IRIS) presenting a punctate pattern with "milky way" appearance on magnetic resonance imaging. Despite the fact that brain imaging and histopathology remain the mainstays for extricating through the expanding galaxy of HIV-related central nervous system dysimmune syndromes and although punctate pattern has been already well acknowledged as a suggestive finding of PML among patients on natalizumab, this radiological presentation is still poorly recognised in AIDS-related PML cases, leading to possible life-threatening diagnostic delays. This is also the first report about intravenous immunoglobulin treatment in AIDS-related PML-IRIS; the favourable clinical and radiological outcome of our case and the preliminary administrations of intravenous immunoglobulins in natalizumab-associated PML-IRIS from literature support probable benefits also among HIV-positive patients.

Antiviral activity of maraviroc plus mirtazapine in a low-risk HIV-negative patient with progressive multifocal leukoencephalopathy

A case of progressive multifocal leukoencephalopathy (PML) is described in an HIV-negative patient with mixed connective-tissue disease (MCTD) on a minimally immunosuppressive treatment with hydroxychloroquine. The patient presented with right-sided weakness, episodes of disorientation and loss of short-term memory and of vision in her right eye. PML was diagnosed by JCV DNA on cerebrospinal fluid and radiological criteria. She was treated with off-label maraviroc and mirtazapine but died two months after hospital admission, despite a surprising decrease in the viral load of cerebrospinal fluid three weeks after starting therapy. Prompt diagnosis and antiviral treatment of PML even in low-risk patients are warranted. Future studies are required to define the therapeutic role of maraviroc (MVC) and mirtazapine in this setting.

High Incidence of Infections in HIV-positive Patients Treated for Lymphoproliferative Disorders

BACKGROUND

Lymphoproliferative disorders are frequently diagnosed in HIV-positive patients and severe infections may occur during antineoplastic treatments: the incidence and impact of such events are not well-characterized.

OBJECTIVE

To describe the occurrence and mortality of incident infections in HIV-positive individuals treated for lymphoproliferative disorders.

METHODS

A retrospective study in HIV-positive adults with lymphoproliferative disorders (2000- 2012) who were hospitalised to receive antineoplastic chemotherapy; antimicrobial prophylaxis with alternate day co-trimoxazole (800/160 mg) was administered to all individuals.

RESULTS

103 patients were included: mostly males (81, 78.6%), Caucasians (101, 98.1%), with a median age of 43 years (39-51). Fifty-eight (56.3%) patients had non-Hodgkin's lymphoma (NHL), thirty-two (29.1%) had Hodgkin's lymphoma (HL) and ten patients (9.7%) had Burkitt's lymphoma (BL). Five year survival was 63.1%: the best survival rates were reported in HL (78.1%), followed by NHL (58.6%) and BL (50%). Forty-four patients (42.7%) developed 82 infections during follow up: identified causative agents were bacteria (35, 42.7%), viruses (28, 34.1%), mycobacteria (7, 8.5%), protozoa (7, 8.5%) and fungi (5, 6.1%). Cytomegalovirus infections (n=17, including 5 endorgan diseases) emerged 53 days after the diagnosis: multivariate analysis showed CD4+ cell count <100/uL as the only independently associated factor (p<0.001, aOR=23.5). Two factors were associated with mortality risk: an IPI/IPS-score of >2 (p=0.004, aOR=6.55) and the presence of CMV disease (p=0.032, aOR=2.73).

CONCLUSION

HIV positive patients receiving treatment for lymphoproliferative disorders suffer from a high incidence of infections and associated mortality risk. Tailored prophylactic strategies need to be considered in this setting.

Diagnostic accuracy of new and old cognitive screening tools for HIV-associated neurocognitive disorders

OBJECTIVES

Considering the similarities between HIV-associated neurocognitive disorders (HAND) and neurodegenerative dementias and the frequency of executive dysfunctions among HIV-positive patients, we evaluated the accuracy of the Frontal Assessment Battery and Clock-Drawing Test together with the Three Questions Test and International HIV Dementia Scale to screen for HAND.

METHODS

A cross-sectional monocentric study was conducted from 2010 to 2017. The index tests were represented by the four screening tools; the reference standard was represented by a comprehensive neurocognitive battery used to investigate 10 cognitive domains. Patients were screened by a trained infectious diseases physician and those showing International HIV Dementia Scale scores ≤ 10 and/or complaining of neurocognitive symptoms were then evaluated by a trained neuropsychologist.

RESULTS

A total of 650 patients were screened and 281 received the full neurocognitive evaluation. HAND was diagnosed in 140 individuals. The sensitivity, specificity, correct classification rate and area under the receiver operating characteristic curve (AUROC) were, respectively, as follows: Frontal Assessment Battery, 40.7%, 95.1%, 68.3% and 0.81; International HIV Dementia Scale, 74.4%, 56.8%, 65.4% and 0.73; Clock-Drawing Test, 30.9%, 73.4%, 53.8% and 0.56; and Three Questions Test, 37.3%, 54.1% and 45.7%. Raising the Frontal Assessment Battery's cut-off to ≤ 16 improved its sensitivity, specificity and correct classification rate to 78.0%, 63.9% and 70.8%, respectively.

CONCLUSIONS

We observed poor screening performances of the Three Questions and Clock-Drawing Tests. While the International HIV Dementia Scale showed a poor specificity, the Frontal Assessment Battery showed the highest correct classification rate and a promising performance at different exploratory cut-offs.

Miliary pulmonary infection after BCG intravesical instillation: a rare, misdiagnosed and mistreated complication

Intravesical Bacillus Calmette-Guérin (BCG) immunotherapy decreases the progression risk of non-muscle-invasive bladder cancer, but potentially yields a broad spectrum of side effects. We report the case of a 73-year-old man affected by miliary pulmonary BCG infection, whose microbiological diagnosis was probably hindered by empiric fluoroquinolones, focusing on imaging and clinical work-up.

Detectable cerebrospinal fluid JCV DNA in late-presenting HIV-positive patients: beyond progressive multifocal leukoencephalopathy?

In the absence of effective prophylaxis and treatment, therapeutic options in HIV-positive patients with progressive multifocal leukoencephalopathy (PML) are limited to antiretroviral therapy: nevertheless, outcome is poor. We conducted a retrospective study (2009-2015) describing the outcome of 25 HIV-positive patients with detectable cerebrospinal fluid JC virus DNA: 14 had a probable PML while the others had evidence of other inflammatory central nervous system (CNS) affecting disorders. In the former group, 6-month mortality was 45.5% vs 21.4 in the latter one: survival was higher than previously described but no predictor of poor outcome was identified. Two patients treated with 5HT2-inhibitors survived. The contributing role of JCV replication in other CNS-affecting disorders needs to be assessed as well as the benefits of 5HT2-inhibitors in HIV-positive patients with proven PML.

Blood Brain Barrier Impairment in HIV-Positive Naïve and Effectively Treated Patients: Immune Activation Versus Astrocytosis

Blood brain barrier (BBB) damage is a common feature in central nervous system infections by HIV and it may persist despite effective antiretroviral therapy. Astrocyte involvement has not been studied in this setting. Patients were enrolled in an ongoing prospective study and subjects with central nervous system-affecting disorders were excluded. Patients were divided into two groups: treated subjects with cerebrospinal fluid (CSF) HIV RNA <50 copies/mL (CSF-controllers) and in late-presenters CD4+ T lymphocytes <100/uL. CSF biomarkers of neuronal or astrocyte damage were measured and compared to CSF serum-to-albumin ratio. 134 patients were included; 67 subjects in each group (50 %) with similar demographic characteristics (with the exception of older age in CSF controllers). CD4 (cells/uL), plasma and CSF HIV RNA (Log₁₀ copies/mL) were 43 (20-96), 5.6 (5.2-6) and 3.9 (3.2-4.7) in LPs and 439 (245-615), <1.69 (9 patients <2.6) and <1.69 in CSFc. BBB impairment was observed in 17 late-presenters (25.4 %) and in 9 CSF-controllers (13.4 %). CSF biomarkers were similar but for higher CSF neopterin values in late-presenters (2.3 vs. 0.6 ng/mL, p < 0.001). CSARs were associated with CSF neopterin (rho = 0.31, p = 0.03) and HIV RNA (rho = 0.24, p = 0.05) in late-presenters and with CSF tau (rho = 0.51, p < 0.001), p-tau (rho = 0.47, p < 0.001) and S100beta (rho = 0.33, p = 0.009) in CSF-controllers. In HAART-treated subjects with suppressed CSF HIV RNA, BBB altered permeability was associated with markers of neuronal damage and astrocytosis. Additional treatment targeting astrocytosis and/or viral protein production might be needed in order to reduce HIV effects in the central nervous system.

Louseborne Relapsing Fever among East African Refugees, Italy, 2015

During June 9–September 30, 2015, five cases of louseborne relapsing fever were identified in Turin, Italy. All 5 cases were in young refugees from Somalia, 2 of whom had lived in Italy since 2011. Our report seems to confirm the possibility of local transmission of louse-borne relapsing fever.

Blood brain barrier impairment is associated with cerebrospinal fluid markers of neuronal damage in HIV-positive patients

Blood brain barrier impairment occurs early in the course of infection by HIV and it may persist in a subset of patients despite effective antiretroviral treatment. We tested the hypothesis that HIV-positive patients with dysfunctional blood brain barrier may have altered biomarkers of neuronal damage. In adult HIV-positive highly active antiretroviral treatment (HAART)-treated patients (without central nervous system infections and undergoing lumbar punctures for clinical reasons) cerebrospinal fluid albumin to serum ratios (CSAR), total tau, phosphorylated tau, 1-42 beta amyloid, and neopterin were measured. In 101 adult patients, cerebrospinal fluid-to-serum albumin ratios were 4.8 (3.7-6.1) with 12 patients (11.9%) presenting age-defined impaired blood brain barrier. A significant correlation was observed between CSAR and total tau (p = 0.005), phosphorylated tau (p = 0.008), and 1-42 beta amyloid (p = 0.040). Patients with impaired blood brain barrier showed significantly higher total tau (201.6 vs. 87.3 pg/mL, p = 0.010), phosphorylated tau (35.3 vs. 32.1 ng/mL, p = 0.035), and 1-42 beta amyloid (1134 vs. 830 pg/mL, p = 0.045). Despite effective antiretroviral treatment, blood brain barrier impairment persists in some HIV-positive patients: it is associated with markers of neuronal damage and it was not associated with CSF neopterin concentrations.

Voriconazole and atazanavir: a CYP2C19-dependent manageable drug-drug interaction

AIM

To investigate the pharmacokinetics of voriconazole when administered to HIV-positive patients receiving treatment with atazanavir-containing therapies according to CYP2C19 genotype.

MATERIALS & METHODS

We describe four HIV-positive patients with pulmonary aspergillosis treated with voriconazole and atazanavir-based regimens (with or without ritonavir). They were managed by assessing their CYP2C19 genotype (CYP2C19*2, rs4244285, G>A, real-time PCR) and therapeutic drug monitoring (HPLC-based validation methods).

RESULTS & CONCLUSION

Voriconazole exposure was variable but Ctrough levels were above 1000 ng/ml in all patients; one CYP2C19 intermediate metabolizer required lower doses of voriconazole (50 mg twice daily) to obtain satisfactory drug concentrations. Atazanavir and ritonavir plasma levels were moderately reduced (area under the curve: -23 and -26%, respectively); raltegravir exposure seemed increased by voriconazole administration (area under the curve: 2.5-fold higher) in a single subject. Coadministration of atazanavir and voriconazole may be feasible in selected HIV-positive patients; therapeutic drug monitoring and CYP2C19 genotyping may optimize exposure of both drugs.

Cytomegalovirus central nervous system compartmentalization in a patient presenting with AIDS

Cytomegalovirus (CMV) central nervous system involvement is uncommon and hardly diagnosed because it can mimic many different conditions. We here present a case of an HIV-positive patient with neurological signs and symptoms (headache, asthenia, confusion, hallucinations, ataxia) with concurrent opportunistic diseases (neurotoxoplasmosis, disseminated Kaposi's sarcoma, disseminated CMV infection). CMV CNS involvement was not initially considered given the observed multiple comorbidities: antiviral treatment duration was probably not adequate given the end-organ disease. Concomitantly, plasma CMV DNA was undetectable while cerebrospinal fluid viral load was 31,340 copies/ml. Ganciclovir treatment followed by oral valganciclovir maintenance was associated with the slow disappearance of symptoms, the improvement of MRI images and the persistent undetectability of CMV DNA. The case here reported highlights the challenges of diagnosing CMV encephalitis in HIV-positive patients (with several cerebral comorbidities), the incomplete knowledge of the appropriate treatment for such a disease and the possibility of CMV replication in the cerebrospinal fluid despite undetectable plasma CMV DNA.

Prevalence and predictors of blood-brain barrier damage in the HAART era

Blood-brain barrier damage (BBBD) is prevalent in HIV-positive patients and may enhance cell trafficking to the central nervous system. A retrospective analysis in adult HIV-positive patients with no central nervous system disease was conducted in order to estimate the prevalence and risk factors of BBBD (according to cerebrospinal fluid to plasma albumin ratios). One hundred fifty-eight HIV-positive adult patients were included. BBBD impairment and intrathecal IgG synthesis were respectively observed in 45 (28.5 %) and 100 patients (63.3 %). Low CD4 nadir and high CSF HIV RNA were independently associated with both abnormalities. BBBD is common in HIV-positive patients, and its main determinants are advanced immune depression and compartmental viral replication.

High interpatient variability of raltegravir CSF concentrations in HIV-positive patients: a pharmacogenetic analysis

OBJECTIVES

To analyse the determinants of raltegravir CSF penetration, including the pharmacogenetics of drug transporters located at the blood-brain barrier or blood-CSF barrier.

METHODS

Plasma and CSF raltegravir concentrations were determined by a validated HPLC coupled with mass spectrometry method in adults on raltegravir-based combination antiretroviral therapy undergoing a lumbar puncture. Single nucleotide polymorphisms in the genes encoding drugs transporters (ABCB1 3435, SLCO1A2, ABCC2 and SLC22A6) and the gene encoding hepatocyte nuclear factor 4 α (HNF4α) were determined by real-time PCR.

RESULTS

In 41 patients (73.2% male, 95.1% Caucasians), the median raltegravir plasma and CSF concentrations were 165 ng/mL (83-552) and 31 ng/mL (21-56), respectively. CSF-to-plasma ratios (CPRs) ranged from 0.005 to 1.33 (median 0.20, IQR 0.04-0.36). Raltegravir trough CSF concentrations (n = 35) correlated with raltegravir plasma levels (ρ = 0.395, P = 0.019); CPRs were higher in patients with blood-brain barrier damage (0.47 versus 0.18, P = 0.02). HNF4α 613 CG genotype carriers had lower trough CSF concentrations (20 versus 37 ng/mL, P = 0.03) and CPRs (0.12 versus 0.27, P = 0.02). Following multivariate linear regression analysis, the CSF-to-serum albumin ratio was the only independent predictor of raltegravir penetration into the CSF.

CONCLUSIONS

Raltegravir penetration into the CSF shows a large interpatient variability, although CSF concentrations were above the wild-type IC50 in all patients (and above IC95 in 28.6%). In this cohort, blood-brain barrier permeability is the only independent predictor of raltegravir CPR. The impact of single nucleotide polymorphisms in selected genes on raltegravir penetration warrants further studies.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

SPIR01 and SPIR02: a two-year 1-day point prevalence multicenter study of infections in intensive care units in Piedmont, Italy

This study reports the results of a one-day point prevalence study of infections performed in 2001 (SPIR01) and 2002 (SPIR02) in a Regional network of ICUs in Piedmont, Italy. The study aims were to illustrate the overall proportion of infected patients and the rate of ICU-acquired infections. Mortality rate was evaluated three weeks after the study days. Resistance pattern of Staphylococcus aureus, coagulase negative Staphylococci and Pseudomonas aeruginosa were recorded. The primary end-point of the study was to document the prevalence and associated risk factors of the ICU-acquired infections, and the impact of infections on mortality. The prevalence of ICU-acquired infection was 30% in SPIR01, and 38.3% in SPIR02. The rate of methicillin-resistance was high among isolates of Staphylococcus aureus and coagulase-negative Staphylococci. The prevalence of ICU-acquired infections was lower than that reported in the EPIC study. In our experience, this Regional survey stimulated further research and collaboration to improve the prophylaxis, diagnosis and treatment of ICU-acquired infections.

[Invasive aspergillosis in an immunocompromised patient: clinical and therapeutic considerations]

The paper describes a case report of a young female with invasive aspergillosis diagnosed after brief treatment with high-dose steroids for autoimmune thrombocytopenia. Early diagnosis of invasive aspergillosis was made with cultures of tracheoaspirates and bronchoalveolar lavage and was confirmed with a transbronchial biopsy. After initial ineffective treatment with liposomal amphotericin B and dissemination from pulmonary to central nervous system involvement, treatment was switched to a combination of voriconazole and caspofungin. After marked clinical and radiological improvement, treatment was switched to the orally administered formulation of voriconazole until the complete disappearance of central nervous system lesion was observed. In the discussion section we underscore the most significant data of the host susceptibility, diagnosis of invasive aspergillosis, complications and treatment. This case ably demonstrates the efficacy of new antifungal agents, even when administered orally, and underscores the variability of host susceptibility to atypical and often unexpected invasive fungal infections.

Infective endocarditis in intravenous drug users from Italy: the increasing importance in HIV-infected patients

BACKGROUND

Intravenous drug users (IDUs) are at increased risk of infective endocarditis (IE).

PATIENTS AND METHODS

Episodes of IE in IDUs were retrospectively analyzed in this multicenter study. Cases were collected between 1986 and 1999. Only definite diagnosis according to the Duke criteria were analyzed.

RESULTS

Two hundred and sixty-three cases, including 100 cases in HIV-positive patients, were observed in IDUs. Any right-sided involvement was detected in 167 out of 263 cases (63.5%) and any left-sided involvement in 115 out of 263 cases (43.7%). The tricuspid valve (TV) alone was affected in 135 cases (51.3%), the mitral valve alone in 32 patients (12.1%), the aortic valve alone in 41 cases (15.6%) and the pulmonic valve alone in 3 cases. Staphylococcus aureus was isolated in 156 cases (59.3%) and Streptococcus spp. in 33 cases (12.5%). No major differences were observed between HIV-negative and HIV-positive patients. Any TV valve involvement was significantly associated with female rather than male gender (p = 0.02). There was a significant association between S. aureus etiology and TV involvement (p < 0.0001). The mortality rate was 16%. On multivariate analysis, only left-side IE (p = 0.0006; OR 5.2; 95% CI 2.0-13.5) and age greater than 35 years (p = 0.0068; OR 3.6; 95% CI 1.4-9.0) were independently associated with mortality.

CONCLUSIONS

Infective endocarditis in IDUs is significantly associated with right-side localization (63.5% for any rightsided heart involvement vs 43.7% for any left-sided heart involvement; OR 2.24; 95% CI 1.55-3.23; p < 0.001). S. aureus is the microorganism most frequently isolated and is significantly associated with TV involvement. Any left-side involvement and age greater than 35 years are independently associated with mortality. HIV infection does not appear to have a significant effect on mortality.

Twelve-Week Treatment of Acute Hepatitis C Virus with Pegylated Interferon- -2b in Injection Drug Users

Injection drug use is the leading risk factor for infection with hepatitis C virus, and interferon (IFN) treatment in this context is associated with a poor rate of adherence. In this article, we review our experience with injection drug users with acute hepatitis C who are treated with pegylated IFN- alpha -2b for 12 weeks. Acute hepatitis C was diagnosed according to standardized criteria, and patients were treated with a median dosage of IFN- alpha -2b of 1.33 microg/kg per week. A sustained virological response was achieved in 17 (74%) of 23 patients. A sustained virological response was achieved in 14 (87%) of 16 patients treated with a dosage of >or=1.33 microg/kg per week and in 3 (43%) of 7 patients treated with a lower dosage. Sustained virological response was significantly associated only with a pegylated IFN- alpha -2b dosage >or=1.33 microg/kg per week (P=.022). A 12-week regimen of pegylated IFN to treat injection drug users with hepatitis C has a compliance that is much higher than that reported with a 24-week regimen. Adverse effects are minimal if patients are carefully selected.

A short course of pegylated interferon-alpha in acute HCV hepatitis

Acute hepatitis C virus (HCV) infection evolves to chronicity in 50-84% cases. Treatment with interferon-alpha (IFN-alpha) was repeatedly found to provide sustained cure rates higher than that in chronic HCV infection, but the optimal treatment strategy has not yet been defined. In a multicentre open-label study, we investigated the therapeutic performance of a short course of pegylated (peg) IFN-alpha in patients with acute HCV hepatitis. Peg IFN-alpha2b, 1.0-1.5 micro g/kg weekly, was administered for 12 weeks. Forty-six patients were enrolled; 26 of them were intravenous drug users. Eleven patients had jaundice. Treatment was started within 1-90 days from the peak alanine aminotransferase. Treatment was well tolerated with a single dropout (2%). Thirty-three of 46 patients (72%) had a sustained virological response (SVR) after a 6 months post-treatment follow-up, 8 (17%) relapsed after treatment and 4 were nonresponders (9%). A lower peak viraemia, receiving at least 1.2 micro g/kg of peg IFN-alpha, and a negative HCV-RNA at week 4 and week 12 were predictors of SVR. Thus, in patients with early (week 4) viral response, a short course of peg IFN-alpha at a weekly dose >1.2 micro g/kg, may be a valuable option for the treatment of acute HCV hepatitis.

Resolution of HCV infection after highly active antiretroviral therapy in a HIV–HCV coinfected patient

The effect of HAART on HCV infection and HCV-RNA plasma levels is controversial. We describe a patient with HIV-HCV coinfection with persistent disappearance of HCV-RNA after immunological and virological response to HAART, and we briefly discuss similar cases reported in the literature.

Penetration of didanosine in semen of HIV-1-infected men

OBJECTIVES

The disposition of antiretroviral agents into genital tissue and fluids is one of the factors implicated in the control of viral replication within the male genital tract and should be an objective of highly active antiretroviral therapy. We have investigated didanosine penetration in seminal plasma of 16 HIV-infected patients.

PATIENTS AND METHODS

A total of 16 patients on didanosine (200 mg every 12 h or 400 mg once daily) participated in the pharmacokinetic study. After the didanosine morning dose, peripheral blood plasma and semen plasma were collected within the intervals 0-4, 4-8 and 8-12 h in the twice-daily regimen and 0-4, 4-12 and 12-24 h in the once-daily regimen.

RESULTS

Within each sampling time interval didanosine concentrations in seminal plasma were higher than in blood. The interquartile range of concentrations in seminal plasma was 292-1217 ng/mL, compared with 50-150 ng/mL in blood plasma. Didanosine could be detected in 14 of the 16 semen samples analysed and in 8 of the 16 blood samples.

CONCLUSIONS

We have demonstrated that didanosine penetrates into the seminal plasma in higher concentrations than in blood plasma.

The Early HCV RNA Dynamics in Patients with Acute Hepatitis C Treated with Pegylated Interferon-α2B

Interferon and pegylated interferon (peg-IFN) are highly effective in patients with acute hepatitis caused by hepatitis C virus (acute hepatitis C, AHC), but the optimal timing of treatment is still under debate. In this open-labelled, uncontrolled trial, 19 patients with AHC, including 12 intravenous drug users (IVDUs), were treated early in the course of the infection with peg-IFN-α2b for 12 weeks. Diagnosis was made according to standardized criteria. The HCV RNA decay was analysed during the first 4 weeks of treatment by quantitative branched-DNA and by qualitative RT-PCR. Of the patients, 11 (58%) had genotype 1. Sustained virological response (SVR) was achieved in 14 out of 19 patients (74%) and the mean time to achieve a negative RT-PCR for HCV RNA was 2.5 weeks. The SVR was associated by univariate analysis with peg-IFN dosage ≥1.33 μg/kg/week ( P=0.026) and HCV RNA level at onset of therapy ( P=0.017). Using a logistic regression model, only peg-IFN dosage ≥1.33 μg/kg/weekly was significantly associated with SVR ( P=0.0379, OR: 14.7; 95% CI: 1.16–185.2). The SVR was 100% and 83.3%, respectively, in genotype 1 and non-1 infected patients treated with a dosage equal to or higher than 1.33 μg/kg, compared with 40% and 50%, respectively, in those who received a lower dosage. Efforts should be made to propose a 12-week treatment with peg-IFN-α2b for AHC, and to maximize peg-IFN dosage. Early treatment is associated with early disappearance of HCV RNA.

Dose-dependent and genotype-independent sustained virological response of a 12 week pegylated interferon alpha-2b treatment for acute hepatitis C

OBJECTIVES

The optimal regimen for acute hepatitis C (AHC) is considered to be a 24 week treatment with interferon (IFN) alpha-2b. A 24 week treatment with pegylated IFN (PEG-IFN) alpha-2b is also effective. This study was designed to assess response rates to a 12 week regimen of PEG-IFN alpha-2b.

PATIENTS AND METHODS

Patients with AHC were treated with PEG-IFN alpha-2b for 12 weeks in an open, non-randomized, prospective cohort study. Diagnosis of AHC was made with positive serum HCV RNA and elevated alanine aminotransferase (ALT) levels with a documented seroconversion or a known risk factor in the preceding 6 months. Treatment was administered within a median of 31 days (range 0-116) of the ALT level peak at a dosage varying from 1.06 to 1.66 microg/kg/week. The primary end-point was a sustained virological response (SVR).

RESULTS

Nineteen patients were treated, of whom 11 patients (57.9%) had HCV genotype 1. Fourteen patients were asymptomatic. An SVR was achieved in 74% of patients and the SVR rate was 100 and 83.3%, respectively, in genotype 1 and non-1 infected patients treated with a dosage>or=1.33 microg/kg, compared with 40 and 50%, respectively, in those who received a lower dosage. An SVR was significantly associated by multivariate analysis only with PEG-IFN dosage>or=1.33 microg/kg/week. No significant association was found with any viral genotype.

CONCLUSIONS

The rate of SVR was independent of the HCV genotype and was significantly associated by multivariate analysis only with the higher PEG-IFN dosage. Early identification and treatment of AHC is likely to decrease the burden of chronic hepatitis, especially when caused by HCV genotype 1.

The early HCV RNA dynamics in patients with acute hepatitis C treated with pegylated interferon-alpha2b

Interferon and pegylated interferon (peg-IFN) are highly effective in patients with acute hepatitis caused by hepatitis C virus (acute hepatitis C, AHC), but the optimal timing of treatment is still under debate. In this open-labelled, uncontrolled trial, 19 patients with AHC, including 12 intravenous drug users (IVDUs), were treated early in the course of the infection with peg-IFN-alpha2b for 12 weeks. Diagnosis was made according to standardized criteria. The HCV RNA decay was analysed during the first 4 weeks of treatment by quantitative branched-DNA and by qualitative RT-PCR. Of the patients, 11 (58%) had genotype 1. Sustained virological response (SVR) was achieved in 14 out of 19 patients (74%) and the mean time to achieve a negative RT-PCR for HCV RNA was 2.5 weeks. The SVR was associated by univariate analysis with peg-IFN dosage < or = 1.33 microg/kg/week (P = 0.026) and HCV RNA level at onset of therapy (P = 0.017). Using a logistic regression model, only peg-IFN dosage > or = 1.33 microg/kg/weekly was significantly associated with SVR (P = 0.0379, OR: 14.7; 95% CI: 1.16-185.2). The SVR was 100% and 83.3%, respectively, in genotype 1 and non-1 infected patients treated with a dosage equal to or higher than 1.33 microg/kg, compared with 40% and 50%, respectively, in those who received a lower dosage. Efforts should be made to propose a 12-week treatment with peg-IFN-alpha2b for AHC, and to maximize peg-IFN dosage. Early treatment is associated with early disappearance of HCV RNA.

Drug–drug interactions and tolerance in combining antituberculosis and antiretroviral therapy

Worldwide, tuberculosis (TB) is one of the most important infectious diseases in subjects with HIV infection. Although effective therapy is available for both conditions, there are major problems in the concurrent treatment of HIV and TB co-infection. In this article the knowledge available on drug-drug interactions between anti-HIV and anti-TB compounds is analysed, particularly with regard to pharmacological interactions secondary to interference with cytochrome P450 enzymes. Within the same setting, facts and possible interpretations of the problems encountered in terms of tolerance and safety of the concurrent treatment of TB and HIV are also reviewed. Current guidelines, as well as additional possible strategies to be adopted in this particular co-morbidity setting are discussed.

Blackwater fever in children, Burundi

Blackwater fever is characterized by acute intravascular hemolysis with hemoglobinuria in patients with Plasmodium falciparum malaria. Its pathogenesis and management are still debated. Nine cases of this syndrome occurred in 2003 at Kiremba Hospital in Burundi in children receiving multiple quinine treatments.

Chemosusceptibility analysis of Plasmodium falciparum imported malaria in Italy

A constant surveillance of susceptibility to antimalarials allows to optimize prevention and treatment of malaria in nonendemic countries. In vitro susceptibility of imported Plasmodium falciparum isolates to chloroquine, quinine, mefloquine, halofantrin, pyronaridine, and amodiaquine was analyzed by WHO Micro-test Mark III; IC50 and IC90 were calculated by WHO Log-probit. Sixty-seven tests were performed. All the infections were acquired in Africa: 14.9% in East Africa and 85.1% in West Africa (WA). IC50 and IC90 (micromol/L) were chloroquine: 0.129 and 0.648; amodiaquine: 1.134 and 5.445; mefloquine: 0.38 and 0.868; quinine: 0.193 and 0.478; halofantrin: 3.27 and 25.35; pyronaridine: 11.504 and 51.996. Higher IC50 and IC90 were observed in East Africa versus West Africa strains. All strains were susceptible to quinine and mefloquine; chloroquine resistance, 14%; amodiaquine resistance, 33%, with cross-resistance to chloroquine (r = 0.93; P < .0001); halofantrin resistance, 3.6%, no cross-resistance with chloroquine; low susceptibility to pyronaridine (66.7%), with cross-resistance with chloroquine (r = 0.38, P < 0.05). Lower levels of chloroquine resistance were observed in 2000-2003 as compared with prior data; thus, the reemergence of chloroquine susceptibility in Africa may be hypothesized.

Clinical pharmacology of antiretroviral therapy

Antiretroviral therapy represents by all means a new branch of anti-infective chemotherapy, and in order to describe the mode of action of antiretrovirals, a series of inferences from anti-bacterial chemotherapy were made. The currently available antiretroviral agents can be classified as time-dependent drugs, and therefore the key pharmacokinetic parameter adopted in their clinical-pharmacological assessment is the concentration at the end of the dosing interval (Ctrough). By focusing on this parameter, the application of Therapeutic Drug Monitoring (TDM) allows for the successful individual tailoring of the drug dosage in some clinical circumstances, such as treatment of drug-resistant infections, drug-drug interactions and side effects. While this procedure has now been sufficiently standardized for protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), no clinical applications are yet recognized for nucleoside/nucleotide reverse transcriptase inhibitors (N/NtRTIs) and fusion inhibitors. The main unfavourable peculiarity of HIV infection, such as the need for lifelong treatment, is one of the reasons why increasing attention is being paid to pharmacological aspects of antiretroviral therapy. Issues like treatment potency, maintenance over time of the immunovirological benefit and long-term side effects require intensive pharmacological investigation in order to obtain the information on which basing the most convenient strategy to be adopted for the therapeutical management of this condition.

Clearance of 14-3-3 protein from cerebrospinal fluid heralds the resolution of bacterial meningitis

The 14-3-3 protein, a cerebrospinal fluid (CSF) marker of neuronal damage that was recently adopted for the diagnosis of Creutzfeldt-Jakob disease, is also found in the CSF of patients with a variety of neurological disorders. We prospectively studied 12 consecutive patients with purulent bacterial meningitis and found that 14-3-3 protein was detected in all patients at admission to the hospital. All patients who recovered cleared 14-3-3 protein from the CSF before discharge from the hospital (this was the first CSF marker to clear), whereas those who died never cleared the protein.

Is a 3-month course of treatment with Peg-interferon effective in acute HCV hepatitis?

From February 2002, all the consecutive patients referring to the Department of Infectious Diseases, University of Turin, who were diagnosed as having acute HCV hepatitis were included in a prospective cohort study to evaluate if a 3-month course of Peg-Interferon alpha-2b (1.5 microg/kg once weekly) is effective to decrease the risk of progression to chronic disease. ALT and HCV-RNA measurements were scheduled at week 4 and 12 during treatment, and 24 weeks after the end of therapy. As of April 2003, ten patients were enrolled in the study. As to HCV genotype, seven patients had type 1 and 3 type non-1. At entry, median HCV-RNA level was 129500 (range: 3000-3100000 copies/mL) and six patients were symptomatic. Treatment was given within 20 days (range: 8-30) of the ALT peak. All patients completing 4 weeks (n = 9) and 12 weeks of treatment (n = 7) had undetectable HCV-RNA. Five patients who completed the 24-week follow-up after the end of treatment had a sustained viral response with ALT levels within normal range. Therapy was well tolerated in all patients. Even if our data are not definitive, our results show that once-weekly administration of Peg-interferon alfa-2b in patients with acute HCV infection may be an effective and convenient regimen.

Successful simplification of HAART in patients with acute primary HIV infection

Aggressive treatment has been advocated for the management of primary HIV infection (PHI), but the composition and the optimal duration of therapy are still to be determined. In addition, time to undetectable viral load (VL), rate and duration of VL suppression as well as subsequent therapeutic choices remain issues widely debated. We evaluated the rate and duration of VL suppression in 12 consecutive patients with PHI given triple-drug treatment with zidovudine, lamivudine and indinavir (highly active antiretroviral therapy, HAART) at onset of the acute illness and subsequently switched to a simplified 2-NRTI-based regimen once VL suppression was maintained for at least 6 months. Throughout the study, no patient discontinued treatment because of symptoms attributed to the study medications. In the study population, undetectable VL was achieved after a median of 84 days (range: 67-135) on HAART and was maintained for a median of 194 days (range: 179-205) before simplification. After switching to simplified maintenace, undetectable VL was maintained in all patients for at least 6 months. Only one patient experienced virological failure, plasma HIV-RNA remaining suppressed for a median foliow-up of 33 months (15-54) and T-CD4+ being steadily higher than 500/mL in the remaining patients. Our results suggest that simplification of HAART in patients promptly treated during PHI and maintaining undetectable VL for at least 6 months before simplification may be a valid option capable of controlling viral replication and maintaining an optimal immunological profile for a prolonged time.