The impact of COVID-19 pandemic control on vaccine-preventable invasive bacterial diseases in Piedmont (Italy).

PURPOSE: The impact of SARS-CoV-2 pandemic on other pathogens is largely unknown. We aimed to compare the prevalence of vaccine-preventable invasive bacterial infections before and during the pandemic in Piedmont (Italy). METHODS: We defined the monthly incidence of S. pneumoniae, H. influenzae and N. meningitides-invasive diseases from January 2010 to June 2021. Then, we compared the mean monthly cases during the previous 5 years (2015-2019) and the monthly cases in 2020 or 2021. RESULTS: We found significant reductions for invasive pneumococcal diseases (IPDs) in adults and H. influenzae-invasive diseases in 2020 and 2021 in comparison to the previous years, but not for invasive meningococcal diseases and IPDs in children. CONCLUSIONS: Further data are needed to confirm these findings and define possible post-pandemic evolutions in the epidemiology of vaccine-preventable invasive bacterial diseases.

SIMIFF study: Italian fungal registry of mold infections in hematological and non-hematological patients.

PURPOSE: We compared the risk factors, the diagnostic tools and the outcome of filamentous fungal infections (FFIs) in hematological patients (HAEs) and non-hematological patients (non-HAEs). METHODS: Prospective surveillance (2009-2011) of proven and probable FFIs was implemented in 23 Italian hospitals. RESULTS: Out of 232 FFIs, 113 occurred in HAEs and 119 in non-HAEs. The most frequent infection was invasive aspergillosis (76.1 % for HAEs, 56.3 % for non-HAEs), and the localization was principally pulmonary (83.2 % for HAEs, 74.8 % for non-HAEs). Neutropenia was a risk factor for 89.4 % HAEs; the main underlying condition was corticosteroid treatment (52.9 %) for non-HAEs. The distribution of proven and probable FFIs was different in the two groups: proven FFIs occurred more frequently in non-HAEs, whereas probable FFIs were correlated with the HAEs. The sensitivity of the galactomannan assay was higher for HAEs than for non-HAEs (95.3 vs. 48.1 %). The overall mortality rate was 44.2 % among the HAEs and 35.3 % among the non-HAEs. The etiology influenced the patient outcomes: mucormycosis was associated with a high mortality rate (57.1 % for HAEs, 77.8 % for non-HAEs). CONCLUSIONS: The epidemiological and clinical data for FFIs were not identical in the HAEs and non-HAEs. The differences should be considered to improve the management of FFIs according to the patients' setting.

Trichoderma species fungemia after high-dose chemotherapy and autologous stem cell transplantation: a case report.

We present a case of Trichoderma fungemia with pulmonary involvement in a multiple myeloma patient, who was severely immunocompromised and heavily treated with high-dose melphalan, and underwent autologous hematopoietic cell transplantation. This is the first report, to our knowledge, of proven Trichoderma fungemia, defined by published criteria, successfully treated with voriconazole.

The reversed halo sign as the initial radiographic sign of pulmonary zygomycosis.

Zygomycosis is an emerging fungal infection that is associated with high mortality in hematological patients and stem cell transplantation (SCT) recipients. Radiology--computed tomography (CT) imaging in particular--facilitates the detection of lung involvement at an early stage of the infection. The reversed halo sign (RHS) has previously been reported in cryptogenetic organizing pneumonia and, more recently, as a manifestation of pulmonary zygomycosis. Here we describe a case of histologically proven zygomycosis due to Rhizopus microsporus in a SCT recipient. A chest CT scan performed on day +6 due to persistent fever unresponsive to antibiotics revealed the presence of the RHS, i.e., a focal ground-glass opacity mass surrounded by a solid ring of consolidation. The patient was treated with a combination of liposomal amphotericin B, caspofungin, and deferasirox, but subsequently developed a large pneumothorax and died on day +49 due to progressive infection. This case supports earlier observations that RHS may be an early radiological sign of zygomycosis, facilitating an aggressive diagnostic strategy.

The histone deacetylase inhibitor ITF2357 has anti-leukemic activity in vitro and in vivo and inhibits IL-6 and VEGF production by stromal cells.

We have investigated the activity of ITF2357, a novel hydroxamate histone deacetylase inhibitor, on multiple myeloma (MM) and acute myelogenous leukemia (AML) cells in vitro and in vivo. ITF2357 induced apoptosis in 8/9 MM and 6/7 AML cell lines, as well as 4/4 MM and 18/20 AML freshly isolated cases, with a mean IC(50) of 0.2 microM. ITF2357 activated the intrinsic apoptotic pathway, upregulated p21 and downmodulated Bcl-2 and Mcl-1. The drug induced hyperacetylation of histone H3, H4 and tubulin. When studied in more physiological conditions, ITF2357 was still strongly cytotoxic for the interleukin-6 (IL-6)-dependent MM cell line CMA-03, or for AML samples maximally stimulated by co-culture on mesenchymal stromal cells (MSCs), but not for the MSCs themselves. Interestingly, ITF2357 inhibited the production of IL-6, vascular endothelial growth factor (VEGF) and interferon-gamma by MSCs by 80-95%. Finally, the drug significantly prolonged survival of severe combined immunodeficient mice inoculated with the AML-PS in vivo passaged cell line already at the 10 mg/kg oral dose. These data demonstrate that ITF2357 has potent anti-neoplastic activity in vitro and in vivo through direct induction of leukemic cell apoptosis. Furthermore, the drug inhibits production of growth and angiogenic factors by bone marrow stromal cells, in particular IL-6 and VEGF.

Periodontal pathogens in periodontal pockets and in carotid atheromatous plaques.

AIM: In the last years the relationship between periodontitis and cardiovascular diseases has been a subject of increasing research. The identification of periodontopathic bacteria in atheromas can contribute to our knowledge of such an association. The aim of our study was to assess the concomitant presence of 5 periodontal pathogens (Actinobacillus actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) in periodontal pockets and in carotid atheromas recovered from the same individuals. METHODS: Twenty-one patients with chronic periodontitis scheduled for endarterectomy for carotid stenosis were enrolled in the study. Subgingival plaque samples and carotid atheromas were examined using the polymerase chain reaction and reverse hybridization techniques by means of specific probes for periodontal bacteria. Human beta-globin amplification was used as internal polymerase chain reaction efficiency control. RESULTS: Three patients were excluded because the endarterectomy specimens were negative to DNA amplification. All subgingival plaque samples were positive for at least one target micro-organism. The prevalence of Tannerella forsythia, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Actinobacillus actinomycetemcomitans was 72.22%, 61.11%, 55.56%, 50%, and 33.33%, respectively. No periodontal bacteria DNA was detected in any endarterectomy specimen. CONCLUSIONS: The presence of periodontal bacteria in atheromatous plaques was not confirmed by this investigation and, thus, no correlation between periodontitis bacteria and micro-organisms involved in the atherosclerotic lesions could be drawn.

Minor histocompatibility antigen-specific T cells with multiple distinct specificities can be isolated by direct cloning of IFNgamma-secreting T cells from patients with relapsed leukemia responding to donor lymphocyte infusion.

Graft-vs-leukemia reactivity after donor lymphocyte infusion (DLI) can be mediated by donor T cells recognizing minor histocompatibility antigens (mHags) on recipient hematopoietic cells. To study the diversity of cells involved in this immune response, hematopoietic cell reactive T cells were directly clonally isolated from peripheral blood of patients entering complete remission after DLI. T cells were briefly stimulated with bone marrow cells from patients pretransplant, and IFNgamma-secreting T cells were directly clonally isolated, and expanded. Cytotoxic T-lymphocyte (CTL) clones from individual patients used multiple distinct HLA-restricting molecules and varied in reactivity against patient-derived normal and/or malignant hematopoietic cells. For each patient, CTL clones specific for known immunodominant mHags as well as distinct unknown mHags were found. Within individual patients, CTL clones using the same HLA-restricting element could show differential recognition patterns, indicating further diversity in mHag reactivity. CTL clones from individual patients exhibiting identical specificities could show oligoclonal origin. In conclusion, the direct cloning technique shows that the response to hematopoietic cells after DLI is directed against multiple distinct mHags, including but not limited to known immunodominant mHags, implying that immunotherapy with T cells against multiple mHag specificities may be more effective in eradicating malignant cells.

Usefulness of sequential Aspergillus galactomannan antigen detection combined with early radiologic evaluation for diagnosis of invasive pulmonary aspergillosis in patients undergoing allogeneic stem cell transplantation.

BACKGROUND: Early diagnosis of invasive pulmonary aspergillosis (IPA) is important as prompt treatment with antifungal drugs may increase patient survival. Our study investigated the efficiency of routine testing of the Aspergillus galactomannan antigen (AGA) test in combination with chest CT scans for IPA diagnosis. PATIENTS AND METHODS: From February 2002 to June 2004, 74 hemato-oncologic patients undergoing allogeneic stem cell transplantation were prospectively studied with serum AGA twice weekly from admission until death or discharge and weekly afterward when possible. Chest CT scans were performed when fever of unknown origin had lasted beyond 3 days of antibacterial therapy. RESULTS: Seven patients were classified with possible IPA and two patients, proven IPA. Fourteen patients showed positive results for AGA (OD index>or=1.0 on two subsequent sera). The sensitivity and specificity of the test were 100% and 93%, respectively; the positive and negative predictive values were 64% and 100%, respectively. All patients with possible/proven IPA showed abnormal CT signs; in four cases, imaging signs followed AGA positivity (median 5 days), whereas in five cases they preceded serologic positivity (median, 8 days). In the nine patients with IPA, antifungal therapy was promptly instituted, including lipid formulations of amphotericin B (n=5) or caspofungin (n=4). In only two of the nine patients (22%) with IPA, the primary cause of death was fungal infection. CONCLUSIONS: The combination of AGA detection and early chest CT scans might be considered useful tools to detect minimal changes of IPA. Based on these findings, aggressive antifungal therapy should be initiated.

Multiple myeloma: comparison of two dose-intensive melphalan regimens (100 vs 200 mg/m(2)).

Several trials have shown the superior impact of high-dose melphalan (usually 200 mg/m(2), MEL200) vs standard therapy in myeloma patients. Intermediate-dose melphalan (100 mg/m(2), MEL100) is also superior to the standard dose, but has not been clinically compared with MEL200. A total of 90 patients at diagnosis were treated with two MEL100 courses. Their clinical outcome was compared with that of a control group of 90 pair mates matched for serum beta2-microglobulin levels and Durie and Salmon clinical stage. These patients were treated at diagnosis with two MEL200 courses. Patient characteristics were similar in both groups except that the median age of the MEL100 group was significantly higher (P<0.0001). Complete remission was 35% after MEL100 and 48% after MEL200 (P=0.08). Median event-free survival (EFS) was 32 months in the MEL100 group and 42 months in the MEL200 group (P<0.005), but overall survival (OS) was not different. Transplant-related mortality was not significantly different. Haematological and extra-haematological toxicity was significantly reduced after MEL100. Despite the significant age difference, tandem MEL100 was less toxic than tandem MEL200, and MEL100 was inferior to MEL200 in terms of EFS but not in terms of OS. The intensified nonmyeloablative MEL100 regimen is an effective first-line treatment.

Direct cloning of leukemia-reactive T cells from patients treated with donor lymphocyte infusion shows a relative dominance of hematopoiesis-restricted minor histocompatibility antigen HA-1 and HA-2 specific T cells.

Donor T cells recognizing hematopoiesis-restricted minor histocompatibility antigens (mHags) HA-1 and HA-2 on malignant cells play a role in the antileukemia effect of donor lymphocyte infusion (DLI) in patients with relapsed leukemia after allogeneic stem cell transplantation. We quantified the contribution of HA-1 and HA-2 specific T cells to the total number of leukemia-reactive T cells in three HA-2 and/or HA-1 positive patients responding to DLI from their mHag negative donors. Clinical responses occurring 5-7 weeks after DLI were accompanied by an increase in percentages HLA-DR expressing T cells within the CD8+ T cell population. To clonally analyze the leukemia-reactive immune response, T cells responding to the malignancy by secreting IFNgamma were isolated from peripheral blood, directly cloned, and expanded. Tetramer analysis and specific lysis of peptide-pulsed target cells showed that 3-35% of cytotoxic T lymphocyte (CTL) clones isolated were specific for HA-1 or HA-2. TCR VB analysis showed oligoclonal origin of the HA-1 and HA-2 specific CTL clones. The HA-1 and HA-2 specific CTL clones inhibited leukemic progenitor cell growth in vitro. The relatively high frequency of HA-1 and HA-2 specific T cells within the total number of tumor-reactive T cells illustrates relative immunodominance of mHags HA-1 and HA-2.

Genetic modification of human T cells with CD20: a strategy to purify and lyse transduced cells with anti-CD20 antibodies.

A retroviral vector has been constructed that contains the human CD20 cDNA under the control of the Moloney murine leukemia virus (Mo-MuLV) LTR. Freshly isolated mononuclear cells are infected for three consecutive days in the presence of PHA and hrlL-2, and a mean 15.9% of the cells (range, 6.5 to 31.7%) acquire a CD3+CD20+ phenotype. Transduced T lymphocytes grow and expand in vitro for up to 3 weeks like mock-infected cells and, as observed for the T lymphoblastoid CEM cell line, CD20 expression is maintained for several months with no change in the growth curve of the cells. CD20-expressing CEM and fresh T lymphocytes can be positively immunoselected on columns using different anti-CD20 antibodies. Exposure to monoclonal chimeric anti-CD20 IgG1(kappa) Rituximab antibody (Roche), in the presence of complement, results in effective and rapid killing of the transduced CD3+CD20+ human T cells in vitro. This approach represents a new and alternative method to gene manipulation with "suicide" genes for the production of drug-responsive T cell populations, a crucial step for the future management of graft-versus-host disease in bone marrow transplant patients.

Detection of human cytomegalovirus myocardial involvement by polymerase chain reaction during systemic infection and correlation with pp65 antigenemia and DNAemia in infected heart recipients.

The presence of human cytomegalovirus DNA was investigated in 103 unfixed endomyocardial biopsies, performed during the first 4 months in 17 heart transplant recipients by polymerase chain reaction. Results were correlated with human cytomegalovirus systemic infection, as detected by the test for the viral lower matrix phosphoprotein pp65 (antigenemia) and by polymerase chain reaction for viral DNA in blood leukocytes (DNAemia). Three patients out of 17 did not develop cytomegalovirus infection and 14 did: 5 had symptomatic disease treated with ganciclovir and 9 developed asymptomatic infection and were not treated. Viral DNA was detected in 24 out of 103 biopsies (23%) from 13 patients: 5 with symptomatic infection during the acute phase of disease (mean levels of pp65: 125+/-232 pp65 positive leukocytes/200,000 examined cells) and 8 patients with asymptomatic infection when the mean antigenemia was 5+/-15/200,000 (4 patients) or when DNAnemia was present in the blood (4 patients). No histological evidence of myocarditis was shown in viral DNA-positive biopsies. No difference in acute rejection was found in viral DNA-positive and DNA-negative biopsy specimens in symptomatic and asymptomatic infected patients. Our experience suggests that during systemic symptomatic and asymptomatic cytomegalovirus infection, polymerase chain reaction can detect a relatively frequent myocardial involvement, but this involvement is not associated with myocarditis or with a higher incidence of acute rejection. THe presence of viral DNA in myocardial biopsies can be a result of high viremia, but it also can be due to low level of viral DNA in circulating infected leukocytes. Polymerase chain reaction is the most sensitive method for cytomegalovirus DNA detection in biopsies, but its results need to be evaluated together with morphology-preserving methods and systemic markers of infection in order to make a correct diagnosis.

Histologic and molecular diagnosis of myocardial human cytomegalovirus infection after heart transplantation.

A total of 879 paraffin-embedded endomyocardial biopsy specimens from 69 heart transplant recipients were studied. In 30 biopsy specimens, the presence of human cytomegalovirus was investigated by routine histologic and immunohistochemical evaluation, in situ hybridization, and polymerase chain reaction. These 30 biopsies were performed in seven patients with clinical human cytomegalovirus infection (four primary and three recurrent infections) and in eight patients with asymptomatic human cytomegalovirus recurrent infection. These endomyocardial biopsy specimens showed grade 0 (n = 9), 1A (n = 12), 1B (n = 7), or 2 (n = 2) acute rejection. No myocarditis with human cytomegalovirus-like inclusion bodies was observed by routine histologic evaluation. Human cytomegalovirus DNA or antigens were not shown by in situ hybridization or by immunohistochemical evaluation, respectively. Viral DNA was detected by polymerase chain reaction in two grade 1A endomyocardial biopsy specimens from two patients with systemic human cytomegalovirus primary infection. These two biopsy specimens were shown to be positive by polymerase chain reaction at the time of the acute phase of the infection as shown by laboratory findings. Therefore cytomegalovirus DNA detected by polymerase chain reaction could result from viral carriers, that is, leukocytes of rejection-related infiltrates or within intramyocardial vessels as a result of a more aggressive expression of the systemic infection in seronegative recipients with cytomegalovirus seropositive donors. Polymerase chain reaction is the most sensitive method for viral DNA detection on paraffin-embedded biopsy specimens, but a multitechnologic approach, including routine histologic evaluation, is required for a proper diagnosis of human cytomegalovirus myocardial infection.

Extrahepatic immunological manifestations of hepatitis C virus in dialysis patients.

BACKGROUND: Hepatitis C virus (HCV) infection may be associated with various extrahepatic immunological disorders. Uremic patients on chronic regular dialytic treatment (RDT) frequently develop immunological abnormalities. The aim of this study was to evaluate the probability that HCV infection creates an increased risk for extrahepatic immunological abnormalities in chronic RDT patients. SUBJECTS AND METHODS: In a series of one hundred sixteen chronic RDT patients, HCV status was determined by anti-HCV antibodies, polymerase chain reaction (PCR) RNA and viral genotyping. After excluding four anti-HCV negative/PCRRNA positive patients, a comparison was made between 51 anti-HCV negative/PCR-RNA negative and 61 anti-HCV positive patients, this latter group including seventeen PCR-RNA negative, fifteen genotype 1, thirteen genotype 2, three genotype 3, four genotype 4, four undeterminable genotype and five mixed genotypes. The following investigations were performed: cryoglobulinemia (presence, titer and, when possible, identification), monoclonal gammopathy, antineutrophil cytoplasm antibodies, antidouble stranded DNA antibodies, circulating immunocomplexes and immunoglobulin levels. RESULTS: Cryoglobulinemia was found in 77% of anti-HCV positive versus 29% of anti-HCV negative patients, and cryocrit > 1% in 50% versus 9.8% respectively, p=<0.01. Also cryoglobulin concentration was higher (logarithmic transformation: 4.38 +/- 0.94 vs 3.11 +/- 1.06, p =< 0.001) in anti-HCV positive versus negative patients. Multivariate logistic regression analysis showed a significantly increased odds ratio (12.0, confidence interval 3.0 to 48.3) for having high levels of cryoglobulins (cryocrit >1%) after adjusting for age and dialytic age. The prevalence of this abnormality did not differ significantly among patients infected with different genotypes, but a tendency towards a lower frequency was observed in the anti-HCV positive/PCR negative subgroup. Cryoglobulins were identified as type I (2 anti-HCV positive case), type II (2 anti-HCV positive and 1 anti-HCV negative case) and type 3 (1 anti-HCV negative case). The frequency of monoclonal gammopathy was not significantly different between anti-HCV positive and anti-HCV negative patients (6.5% versus 2%) as well as that of the other parameters evaluated except for IgG concentration which was higher in the anti-HCV positive group (1,685 +/-605 versus 1349 +/- 352 mg/dl, p 0.006). Five events, potentially linked to HCV infection, occurred in our anti-HCV positive patients: 2 cases of porphyria cutanea, 1 case of unexplained peripheral neuropathy, 1 cutaneous leukocytoclastic vasculitis, 1 death for non-Hodgkin's lymphoma. In one anti-HCV positive patient treated with interferon-alpha, the presence of cryoglobulins, monoclonal gammopathy and high IgG levels strictly paralleled that of viremia, disappearing during the recovery phase under treatment and reappearing shortly after stopping treatment. CONCLUSIONS: HCV infection provides a significantly increased risk for developing extrahepatic immunological abnormalities also in chronic RDT patients. It is possible that the clinical relevance of this event might be scant because of the low level of these abnormalities, but an awareness of its possibility should to be taken into account.

[Correlations between viral serology and different clinical characteristics in patients with lupus nephropathy]. / Correlazioni tra sierologia virale e differenti caratteristiche cliniche dei pazienti con nefropatia lupica.

BACKGROUND: Relationships between viral infections and autoimmune diseases are complex and debated: on the one hand, patients with LES are particularly prone to develop viral infections, on the other, some virus are thought to play a role both in triggering the onset of the immunologic disease and in conferring peculiar clinical features to flare-ups. METHODS: This study has drawn an epidemiologic profile of viral pathology from Epstein Barr virus, Parvovirus B 19 and Cytomegalovirus in 60 patients with LES followed-up for a period ranging from 13 to 340 months (on average 158 months). RESULTS: Cytomegalovirus seropositivity has turned out to be a strong, statistically significant risk factor for vascular accidents and especially for peripheral ones, such as Raynaud phenomenon, ulcers and distal necrosis (OR = 6.5 IC = 0.7-7.9* p = 0.037). CONCLUSIONS: Although Cytomegalovirus seropositivity is associated with an increased frequency of LAC/ACA, its relationship with vascular events does not seem to be mediated through such antibodies, apparently acting as an independent risk factor which also works in LAC/ACA negative patients. Parvovirus B 19 seropositivity has turned out to be the only increased risk factor for the development of anemia, although not reaching statistical significance, whereas Epstein Barr seropositivity does not appear to influence clinical features significantly.

Zygomycosis in Italy: a survey of FIMUA-ECMM (Federazione Italiana di Micopatologia Umana ed Animale and European Confederation of Medical Mycology).

The aims of the study were to analyze the clinical and epidemiological characteristics and treatments for patients who developed zygomycosis enrolled in Italy during the European Confederation of Medical Mycology of medical mycology survey. This prospective multicenter study was performed between 2004 and 2007 at 49 italian Departments. 60 cases of zygomycosis were enrolled: the median age was 59.5 years (range 1-87), with a prevalence of males (70%). The majority of cases were immunocompromised patients (42 cases, 70%), mainly hematological malignancies (37). Among non-immunocompromised (18 cases, 30%), the main category was represented by patients with penetrating trauma (7/18, 39%). The most common sites of infection were sinus (35%) with/without CNS involvement, lung alone (25%), skin (20%), but in 11 cases (18%) dissemination was observed. According to EORTC criteria, the diagnosis of zygomycosis was proven in 46 patients (77%) and in most of them it was made in vivo (40/46 patients, 87%); in the remaining 14 cases (23%) the diagnosis was probable. 51 patients received antifungal therapy and in 30 of them surgical debridement was also performed. The most commonly used antifungal drug was liposomal amphotericin B (L-AmB), administered in 44 patients: 36 of these patients (82%) responded to therapy. Altogether an attributable mortality rate of 32% (19/60) was registered, which was reduced to 18% in patients treated with L-AmB (8/44). Zygomycosis is a rare and aggressive filamentous fungal infection, still associated with a high mortality rate. This study indicates an inversion of this trend, with a better prognosis and significantly lower mortality than that reported in the literature. It is possible that new extensive, aggressive diagnostic and therapeutic procedures, such as the use of L-AmB and surgery, have improved the prognosis of these patients.

In vitro compared activity of telithromycin and azithromycin against northwest Italian isolates of Streptococcus pyogenes and Streptococcus pneumoniae with different erythromycin susceptibility.

AIMS: This study compared the in vitro activity of telithromycin with that of azithromycin against 438 Streptococcus pyogenes and 198 Streptococcus pneumoniae, isolated over the period 2005-2007 from specimens of different human origin obtained in three Piemonte Region's hospitals. METHODS AND RESULTS: The determination of antimicrobial activity was evaluated by the microdilution broth method and the erythromycin-resistant (Ery-R) phenotypes by the triple-disc test. Exactly 78.8% of S. pyogenes and 69.2% of S. pneumoniae were erythromycin-susceptible (Ery-S). Concerning S. pyogenes, telithromycin was active against M and inducible MLS(B), subtype-C, phenotypes but not against constitutive MLS(B) strains. Telithromycin acted well against all S. pneumoniae, irrespective of their mechanism of macrolide-resistance. On the contrary, the Ery-R isolates, both S. pyogenes and S. pneumoniae, were resistant to azithromycin. CONCLUSIONS: Our results indicate that macrolide resistance in streptococci still persist in northwest Italy (21.2% of S. pyogenes and 308% of S. pneumoniae) and that telithromycin is confirmed as being extremely active even against recent clinical Ery-R streptococcal isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study emphasizes that an active surveillance of the phenotype distribution and antibacterial resistance in streptococci is essential in guiding the effective use of empirical treatment option for streptococcal infections, also at regional level.

Gemtuzumab ozogamicin (Mylotarg) has therapeutic activity against CD33 acute lymphoblastic leukaemias in vitro and in vivo.

Gemtuzumab ozogamicin (GO) is a humanized anti-CD33 antibody conjugated with the cytotoxic drug calicheamicin and approved for the treatment of relapsed acute myeloid leukaemia. As approximately 18% of acute lymphoblastic leukaemias (ALL) are also CD33 positive, we have investigated the cytotoxic activity of GO on CD33+ ALL cells in vitro and in vivo. 10 ng/ml GO induced 30-95% inhibition of thymidine uptake and 30-70% cell death in four freshly isolated and one in vivo passaged CD33+ ALL-cell cultures. Furthermore, an in vivo model of a CD33+ ALL carrying the Philadelphia chromosome [t(9;22)] was established. 5 x 10(6) ALL-2 cells inoculated in the tail vein of severe combined immunodeficient mice engrafted into haematopoietic organs, reaching a mean of 70%, 61% and 69% human CD45+ cells in bone marrow, spleen and liver, respectively, at 35 d. To test the therapeutic activity of GO, 50 or 100 microg immunotoxin was inoculated i.p. on days 7, 11 and 15 following tumour-cell inoculation. GO treatment dramatically inhibited expansion of ALL-2 cells in all tested organs and increased survival of tumour-injected animals by 28-41 d, relative to controls. These data demonstrated that GO is active both in vitro and in vivo against CD33+ ALL cells.

Infectious complications following nonmyeloablative allogeneic hematopoietic stem cell transplantation.

Nonmyeloablative hematopoietic stem cell transplantation (NST) has been explored in hematological malignancies and solid tumors in an attempt to minimize treatment-related toxicity. Whether this approach is associated with reduced risk of infectious complications is unclear. The aim of the current study was to evaluate the infectious complications in a series of 32 consecutive adult patients who received NST at our institution. Peripheral blood stem cell grafts (n=30) or marrow grafts (n=2) were infused from human leukocyte antibody (HLA)-matched sibling (n=30), partially matched related (n=1), or unrelated (n=1) donors. Neutropenia developed in two-thirds of patients and lasted 16 days. Acute graft-versus-host disease (GVHD) grade II to IV was observed in 25% of patients, whereas 35% of patients had signs of extensive chronic GVHD. Twenty-two patients (69%) had at least one significant infectious episode. Bacteremia occurred in 19% of patients (n=5 gram-positive, n=1 gram-negative microorganisms). Cytomegalovirus (CMV) infection was observed in 10 out of 28 (36%) evaluable patients; 4 of these had recurrent or persistent CMV antigenemia requiring a second-line treatment, but eventually the viremia cleared. No patients experienced CMV disease. Fungal infections were documented in five (16%) patients, comprising invasive fungal infections in two cases and mucosal fungal infections in three. Four patients died of transplant-related causes, and three of these died before day +100. Infection was considered the primary cause of death in one patient (pulmonary aspergillosis) and contributed to death in another two. The actuarial probability of nonrelapse mortality at 100 days was 10% (95% confidence interval, 3-26%). Our preliminary results suggest that NST is associated to a low incidence of bacteremia or fungal and viral infections. Whether these findings would translate into an improved overall survival needs to be confirmed in larger prospective studies.

Rapid retroviral infection of human haemopoietic cells of different lineages: efficient transfer in fresh T cells.

In order to develop a clinically feasible gene marking approach, we have used the recently described PINCO retroviral expression system, composed of the enhanced green fluorescence protein (EGFP) cDNA driven by Moloney MLV LTR and packaged in the Phoenix amphotropic cell line. Two T, five B, one erythromyeloid and three myeloid cell lines were successfully infected with % GFP+ cells ranging from 4% to 79%, showing a lineage-dependent difference in infection susceptibility, with the myeloid cells being the least efficiently infected. We also infected normal mononuclear peripheral cells cultured in PHA and rhIL-2 for 2 d, and obtained an average of 30% GFP+ cells, all present within the CD3+ population, with CD4+ and CD8+ cells being equally infected. Finally, the tonsillar purified B population showed lower levels of infectivity (6%) whereas high susceptibility was shown by normal human umbilical vein endothelial cells (57%). Highly purified CD34+ cells were also susceptible, varying from 6% to 10% GFP+ cells. Immature myeloid/erythroid progenitors have been infected which stably expressed the GFP protein during further differentiation in culture. The GFP+ T cells were FACS-sorted rapidly upon infection, subsequently cultured and the fluorescence intensity monitored. In all cases the difference in percentage of GFP+ cells did not correlate with the percentage of S/G2/M cycling cells as determined at the moment of infection or with the expression levels of Ram-1 amphotrophic receptor. The improved safety of this retroviral system, the rapidity of the technique, the high efficiency of infection with respect to normal T lymphocytes (in this last case higher than previously reported) and the lack of need for in vitro selection make this system favourable for clinical development.