Ben Abdeladhim

Randomized Trial of Prevention of Catheter-Related Bloodstream Infection by Continuous Infusion of Low-Dose Unfractionated Heparin in Patients With Hematologic and Oncologic Disease

PURPOSE Infection is a serious complication of central venous catheters in immunocompromised patients. Catheter-related infection may be caused by fibrin deposition associated with catheters. Interventions designed to decrease fibrin deposition have the potential to reduce catheter-related infections. The purpose of this study was to evaluate the role of low-dose unfractionated heparin in preventing catheter-related bloodstream infection in patients with hemato-oncological disease. PATIENTS AND METHODS This study was a randomized, controlled trial in which patients with nontunneled catheters were randomly assigned to receive either intravenous unfractionated heparin (continuous infusion of 100 U/kg per day) or 50 mL/day of normal saline solution as a continuous infusion (control group). Heparin was continued until the day of discharge. Catheter-related bloodstream infection was defined according to Infectious Disease Society of America guidelines. RESULTS Two hundred and eight patients were randomly assigned. Four patients were excluded after assignment. Ultimately, 204 patients were analyzed. Catheter-related bloodstream infection occurred in 6.8% (7 of 102 catheters) of those in the heparin group (2.5 events per 1,000 days) and in 16.6% (17 of 102 catheters) of those in the control group (6.4 events per 1,000 days) (P = .03). No other risk factors were found for the development of catheter-related bloodstream infection. Four and five patients experienced severe bleeding in the heparin and control groups, respectively (P = .2). We did not observe heparin-induced thrombocytopenia. CONCLUSION The use of continuous infusion of low-dose unfractionated heparin (100 U/kg per day) can be a practical and economical approach to the prevention of catheter-related bloodstream infection in patients with hemato-oncological disease.

Hemophagocytic syndrome after hematopoietic stem cell transplantation: a prospective observational study

The aim of this prospective observational study was to evaluate the incidence of hemophagocytic syndrome (HPS) after hematopoietic stem cell transplantation (HSCT). Between July 2006 and December 2007, all patients who received a HSCT in our institution were included in this study. All the following criteria were needed for the diagnosis of HPS: sustained fever over 7 days; cytopenia (neutropenia and/or thrombocytopenia); presence of more than 3% mature macrophages in bone marrow; hyperferritinaemia (>1,000 ng/mL). During this study, 171 patients received a HSCT (68 allogeneic and 103 autologous). The median age was 32 years (3–62). We observed six cases of HPS (6/68; 8.8%) after allogeneic stem cell transplantation (ASCT): one case of EBV-related HPS, two cases of CMV-related HPS, and three cases with no evidence of bacterial, fungal or viral infections. We observed only one case of CMV-related HPS (1/103; 0.9%) after autologous stem cell transplantation. Four patients died despite aggressive supportive care. To our knowledge, this is the first prospective observational study conducted with the aim to evaluate the incidence of HPS after HSCT. This study provides a relatively high incidence of HPS after ASCT. When sustained fever with progressive cytopenia and hyperferritinaemia are observed, HPS should be suspected, and bone marrow aspirate considered. The rapid diagnosis of HPS and the early initiation of an appropriate treatment are essential for patient management.

Effectiveness of fixed 50% nitrous oxide oxygen mixture and EMLA cream for insertion of central venous catheters in children.

Although the equimolecular mixture of oxygen and nitrous oxide (EMONO) seems a good choice to relieve procedure‐related pain in children, it has not been evaluated for insertion of central venous catheters in children. To assess the safety and the effectiveness of this gas mixture for insertion of central venous catheters, we conducted a prospective observational study.

Analysis of cytomegalovirus (CMV) viremia using the pp65 antigenemia assay, the amplicor CMV test, and a semi-quantitative polymerase chain reaction test after allogeneic marrow transplantation

Abstract: A pp65 antigenemia assay for polymorphonuclear leukocytes (PMNLs) (CINAkit Rapid Antigenemia), and a qualitative polymerase chain reaction (PCR) test for plasma ‘PCR‐P qual’ (Amplicor cytomegalovirus [CMV] test) were performed for 126 samples (blood and plasma) obtained from 18 bone marrow transplant patients, over a 9‐month surveillance period. Among those samples, 92 were assayed with a semi‐quantitative PCR test for PMNLs ‘PCR‐L quant.’ The number of samples with a positive CMV test for antigenemia and PCR‐P qual assays was 20.63% and 12.7%, respectively, whereas the PCR‐L quant assay was positive in 48 of the 92 samples assayed (52.17%). The rates of concordance of the results of PCR‐P qual and antigenemia, PCR‐P qual and PCR‐L quant, antigenemia and PCR‐L quant were 92%, 65.2% and 66.8%, respectively. The analysis of the results for the 92 specimens tested by all 3 methods showed a rate of concordance of 63% among all methods. Good agreement (κ=0.72) was found only between pp65 Ag and PCR‐P qual assays. Clinical disease correlates with an antigenemia high viral load. Three patients had CMV disease despite preemptive therapy, and all of them had graft‐versus‐host‐disease (GVHD). PMNLs‐based assays are more efficient in monitoring CMV reactivation, but for high‐risk patients with GVHD, more sensitive assays (real‐time PCR) must be done.

Detection of SHV-1 β-lactamase in Pseudomonas aeruginosa strains by genetic methods

Twelve multidrug-resistant Pseudomonas aeruginosa (MDRPA) isolates were recovered over a period of two years in the National Bone Marrow Transplant Centre of Tunisia. MDRPA isolates were isolated from seven patients and from three environmental samples. Isoelectric focusing revealed pIs of 8.2, 5.5 and 7.6 in all MDRPA isolates. These strains produced the OXA-18 extended spectrum beta-lactamase and an SHV type beta-lactamase as shown by screening PCR analysis. DNA hybridization confirmed this inference, detecting bla(SHV) gene in these isolates. Pulsed-field gel electrophoresis (PFGE) defined one predominant genomic group; group A (seven isolates) and four different genotypes containing one to two isolates. Clonally related isolates were recovered from three patients and from two washbasins. Sequencing DNA of cluster representative strains identified the classical bla(SHV-1) gene. For these strains, the nucleotide sequence of the structural bla(SHV-1) gene was nearly identical to those previously described. Such enzyme has not been reported from P. aeruginosa. This is the first report of the SHV-1 penicillinase in epidemic P. aeruginosa strain.

Identification des gènes de β-lactamase à spectre étendu de type SHV chez Pseudomonas aeruginosa par PCR-restriction fragment length polymorphism et insertion site restriction-PCR

We propose a simple and rapid method to discriminate SHV-type extended spectrum beta-lactamase (ESBL) genes in P. aeruginosa based on PCR techniques (PCR-RFLP and RSI-PCR). We studied 22 producing ESBL P. aeruginosa strains isolated from seven immunocompromised patients (19 isolates) and from environmental swabs (three isolates) at the Bone Marrow Transplantation Center of Tunis. Screening PCR with primer pairs designed to detect gene encoding TEM, SHV, OXA group I, OXA group II, OXA-18 and PER-1 ESBL was positive for bla(OXA18) and bla(SHV) genes in all isolates. Pulsed field gel electrophoresis using SpeI endonuclease defined five genotypic groups. For at least one isolate corresponding to each genotype observed, restriction of PCR products by DdeI and BsrI revealed the same restriction pattern that the bla(SHV-1) negative control; in the same way, RSI-PCR products digestion by NruI, thus excluding 35, 238 and 240 mutations characterizing reported ESBL in P. aeruginosa (SHV-2a, SHV5 et SHV12), and suggesting that studied bla(SHV) genes were not ESBL ones. Genomic DNA hybridization by southern blot with probe consisting in bla(SHV-1) gene was positive in these isolates. Sequencing the full-length open reading frame revealed nucleotide sequence of the bla(SHV-1). PCR-RFLP and RSI-PCR results were then confirmed. This approach is effective for screening P. aeruginosa for ESBL genes carriage in epidemiological studies and for detecting new variants.

Effect of once-a-day fractionated total body irradiation on the risk of relapse after non-T-cell-depleted HLA-matched sibling transplantation

PurposeThe aim of this study was to assess the impact of fractionated total body irradiation (F-TBI) on treatment-related mortality (TRM) and relapse in patients who received a non-T-cell-depleted allogeneic stem cell transplantation (ASCT) for hematological malignancies.Materials and methodsBetween March 2003 and December 2004, a total of 24 patients with HLA-identical sibling donors entered this study and received three doses of 3.33 Gy F-TBI separated by 24 h and cyclophosphamide or etoposide.ResultsAt a median follow-up of 37 months (range 29–47 months), 4 of the 24 patients (16.6%) died of TRM. Relapse occurred in 10 patients at a median of 9 months (range 2–18 months). Overall, 13 of 24 patients (54%) died. Relapse was the most common cause of death (9/13). The 2-year actuarial survival rate was 46% (±11%).ConclusionIn our experience, ASCT conditioned with F-TBI was associated with low TRM but a high early relapse rate in patients with hematological malignancies.