Detection and pharmacokinetics of a cytomegalovirus (CMV) DNA plasmid in human plasma during a clinical trial of an intramuscular CMV vaccine in hematopoietic stem cell transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) causes significant morbidity and mortality in solid organ and bone marrow transplant recipients. DNA vaccines can provide both humoral and cellular immunity without exposing immune-compromised persons to replication-competent CMV. METHODS: We studied the kinetics of CMV vaccine DNA in plasma. The samples were obtained from vaccine recipients who were enrolled in a double-blinded, placebo-controlled clinical trial of an intramuscular, plasmid-based, bivalent DNA vaccine for CMV in stem cell transplant recipients. Residual specimens on patients enrolled in the vaccine trial were saved until the trial was unblinded and published. Quantitative real-time polymerase chain reaction (PCR) was used to detect and quantify CMV glycoprotein B (gB) DNA in plasma from 4 recipients of the vaccine. The melting temperature of the vaccine gB amplicon was 62.4°C, compared to 68.8°C, which is seen with the wild-type virus. RESULTS: Sequence analysis revealed that there were 3 mismatches between the fluorescent resonance energy transfer probe and the vaccine DNA sequence. CONCLUSION: Because preemptive treatment of CMV disease in stem cell transplant patients is based on quantitative PCR analysis of viral sequences in plasma, it is important that vaccine sequences not be confused with those in wild-type virus. Confusion could lead to treatment with toxic medications, potentially compromising the transplant. Effects of PCR target choice and amplicon detection techniques on patient management and vaccine trials are discussed.

Vaccination adherence in hematopoietic stem cell transplant patients: a pilot study on the impact of vaccination cards and reminder telephone calls.

BACKGROUND: The Karmanos Cancer Center Bone Marrow Transplant (KCC BMT) Center updated the vaccination protocol for transplant patients based on joint guidelines recently published by European Bone Marrow Transplantation, Centers for Disease Control, Infectious Diseases Society of America, and the American Society for Bone Marrow Transplantation. The objectives for this study were to determine the impact of vaccination cards and telephone outreach on vaccine adherence and to determine the reasons for missed or delayed vaccinations. METHODS: Retrospective analysis consisted of autologous and allogeneic hematopoietic stem cell transplant (HSCT) patients at the KCC BMT Clinic who received vaccines based on the guidelines published in 2009. Adherence was calculated as percentage of vaccines missed over the vaccination period. RESULTS: Overall, 37 of 111 patients (33%) missed at least 1 vaccine set and 29 patients (26%) received 1 set later than recommended. Reasons for missed and delayed vaccines included neutropenia/thrombocytopenia, anticoagulation, active infection, and graft-versus-host complications. CONCLUSIONS: Current guidelines recommend a complex vaccination schedule for the HSCT recipients, which may lead to difficulties with adherence. Our study shows that missed and delayed vaccinations are common in both autologous and allogeneic HSCT recipients. Methods to improve adherence are needed.

Clinical impact of the use of 16S rRNA sequencing method for the identification of "difficult-to-identify" bacteria in immunocompromised hosts.

Molecular method of 16S rRNA sequencing is reported to be helpful in the accurate identification of organisms with ambiguous phenotypic profiles. We analyzed the use of 16S rRNA sequencing method to identify clinically significant, "difficult-to-identify" bacteria recovered from clinical specimens, and evaluated its role in patient management and consequent clinical outcome. Among the 172 "difficult-to-identify" bacteria recovered over a 4-year period, 140 were gram-positive cocci or gram-negative bacilli; identification by 16S rRNA did not play a role in the management of patients infected with these bacteria. From 32 patients, 33 "difficult-to-identify" gram-positive bacilli were identified; the organisms were mycobacteria, Nocardia, Tsukamurella, Rhodococcus, and Gordonia. In 24 patients for whom clinical data were available, results from the 16S rRNA sequencing method led to treatment change in 14 immunocompromised patients (including 7 hematopoietic stem cell recipients and 1 liver transplant recipient). Therapy was modified in 9 patients, initiated in 3 patients, and discontinued in 2 patients. Most patients' therapy was switched to oral antibiotics with discontinuation of intravascular catheters, facilitating early hospital discharge. All 14 patients were alive 30 days after infection onset. The present study demonstrates the clinical application of 16S rRNA sequencing method to identify "difficult-to-identify" mycobacteria and other gram-positive bacilli in clinical specimens, particularly in immunocompromised hosts.

Weissella confusa: an unexpected cause of vancomycin-resistant gram-positive bacteremia in immunocompromised hosts.

We report the first case of Weissella confusa bacteremia in an allogeneic hematopoietic stem cell transplant patient. After engraftment and discharge, the patient returned with fever and graft failure and was started on an empiric regimen of aztreonam and vancomycin. A blood culture grew an alpha-hemolytic, gram-positive coccus forming pairs and chains, originally thought to be a viridans Streptococcus and a skin contaminant. The isolation of the organism from multiple blood cultures, and the presence of vancomycin resistance prompted identification and additional susceptibility testing. The RapID(™) Str panel, which has W. confusa in its database, provided multiple incorrect identifications. The MicroScan WalkAway 96 SI, using PC-20 or -29 panels, also did not identify this bacterium, because it is not in their database. The organism was identified as W. confusa by 16S rDNA sequencing. Antibiotic susceptibility determination by Etest revealed vancomycin resistance and daptomycin susceptibility. Therapy was changed to daptomycin, and the infection resolved. Additionally, W. confusa sepsis, with multiple positive blood cultures, developed in a patient in the burn unit at our medical center. The patient's blood cultures remained positive until vancomycin was discontinued and daptomycin therapy initiated. Infections with vancomycin-resistant, gram-positive cocci are emerging among immuno compromised hosts. Under appropriate circumstances, clinicians need to request that the laboratory perform susceptibility testing and accurate identification, by nucleic acid sequencing if necessary. Sequencing of 16S rDNA is an important tool in the accurate identification of unusual pathogens.

Listeria grayi: vancomycin-resistant, gram-positive rod causing bacteremia in a stem cell transplant recipient.

We report the first case of Listeria grayi bacteremia in a stem cell transplant recipient. The patient developed bacteremia with a gram-positive rod that was initially thought to be Corynebacterium species and a skin contaminant. The organism grew in multiple blood cultures and therapy with vancomycin was initiated. The API Coryne (version 3.0) identified the organism as L. grayi. Susceptibility testing by Etest suggested that the organism was resistant to vancomycin, but susceptible to ampicillin. After therapeutic change from vancomycin to ampicillin, the bacteremia cleared. Empiric therapy with vancomycin for all gram-positive bacterial infections is not appropriate. Accurate identification and antibiotic susceptibility is important, particularly in those with persistent bacteremia.

Rhodococcus equi lung infection in an allogeneic hematopoietic stem cell transplant recipient.

In this report, we describe a case of Rhodococcus equi lung infection diagnosed in an allogeneic hematopoietic stem cell transplant with oral graft-versus-host disease 3 months after stem cell infusion. The lung lesion persisted despite an approximate 3 months of vancomycin therapy, but then responded favorably to a combination of intravenous ertapenem at 1 g daily and oral rifampin at 600 mg daily for 1 month. An overview of Rhodococcus infection in transplant recipients is presented. This case and the discussed literature suggest that combination antibiotic therapy is warranted in patients with decreased humoral and cellular immunity.

Non-bacterial infections in allogeneic non-myeloablative stem cell transplant recipients.

Data on non-bacterial infections during allogeneic non-myeloablative hematopoietic stem cell transplantation (HSCT) are widely different. We evaluated data on 48 consecutive patients who received a conditioning regimen with fludarabine and cyclophosphamide (73%) or fludarabine and total body irradiation (27%) and then underwent allogeneic non-myeloablative HSCT. Cytomegalovirus (CMV) infection was common and occurred in 48% of patients; 3 patients developed CMV disease, and all survived. CMV reactivation was found to be common with both conditioning regimens in our patient population. Invasive aspergillosis occurred in 4 patients (8%) and 3 died. Other serious non-bacterial infections were uncommon. Review of the available literature on non-myeloablative HSCT suggests that the frequency and type of opportunistic infections vary considerably.

Effectiveness of amphotericin B lipid complex (ABLC) treatment in allogeneic hematopoietic cell transplant (HCT) recipients with invasive aspergillosis (IA).

A total of 85 allogeneic hematopoietic cell transplant (HCT) recipients with invasive aspergillosis treated with amphotericin B lipid complex (ABLC) were identified from the Collaborative Exchange of Antifungal Research (CLEAR) database. Of these patients, 78% (66/85) presented with pulmonary aspergillosis. Graft-versus-host disease (GVHD) was present in 24 of 85 patients. The response rate to ABLC was 31% (26/85) overall and 21% (5/24) in patients with GVHD. The overall response rate to first-line ABLC treatment was 41% (11/27). Four of nine (44%) patients with GVHD responded to first-line treatment with ABLC, while only one of 13 (8%) responded to ABLC as second-line therapy. Five of 18 (28%) and four of 14 (29%) patients, respectively, responded to sequential or concurrent treatment with ABLC and itraconazole. None of seven patients responded who continued receiving itraconazole after the start of ABLC therapy. At the end of ABLC therapy, serum creatinine had doubled in 12% of patients (10/85), and 2% (2/85) had developed a requirement for dialysis. These data suggest that ABLC, especially when administered as first-line therapy, can result in clinical response even in the most immunocompromised patients, that is, HCT recipients with GVHD, with minimal effects on renal function.

Caspofungin.

Available systemically effective antifungal agents for the treatment of invasive fungal infections are few. With the increasing recognition of a need for newer antifungal drugs, caspofungin has been introduced as the first member of a new class of compounds called echinocandins. This paper reviews the chemistry and mechanism of action of caspofungin, its activity in vitro and in animal models, and clinical pharmacokinetics,clinical efficacy and safety in patients.

Inhibition of H(+)-ATPase-mediated proton pumping in Cryptococcus neoformans by a novel conjugated styryl ketone.

We investigated the in vitro susceptibility of clinical isolates of Cryptococcus neoformans to the novel conjugated styryl ketone NC1175 by broth microdilution. The MIC(90) and the MFC of NC1175 for C. neoformans were 1 and 2 mg/L, respectively. NC1175 at low concentrations (1-4 mg/L) completely inhibited the glucose-induced acidification of the external medium caused by the extrusion of intracellular protons mediated by the plasma membrane located H(+)-ATPase. These data suggest that NC1175 is a fungicidal agent for C. neoformans and its possible cellular target(s) include the H(+)-ATPase.

Low infectious morbidity after intensive chemotherapy and autologous peripheral blood progenitor cell transplantation in the outpatient setting for women with breast cancer.

Autologous peripheral blood progenitor cell (PBPC) transplantation is increasingly employed in the outpatient setting, yet data on early complications following PBPC transplantation are scant. We evaluated 105 women with high-risk primary or metastatic breast cancer who were treated at a single institution during 1996--1997. The mean duration of neutropenia (absolute neutrophil count, <500 cells/mm(3)) was 7.5 days. Twenty-nine percent of women remained afebrile throughout the neutropenic period. Of the remaining 71%, most (64 of 75) had fever of unknown origin. Infections, mostly of mild severity, occurred in 34% of women; these infections included bacteremia due to gram-positive organisms, catheter site infection, cellulitis, pneumonia, oral candidiasis, herpes simplex virus infection, and vaginitis. Fifty percent of PBPC transplant recipients required hospital admission, usually because of persistent fever; the mean duration of hospitalization was 3 days. No deaths or serious adverse events occurred. Such reduced infectious morbidity may be a consequence of minimal oral and/or gastrointestinal mucositis associated with the conditioning regimen and broad-spectrum antimicrobial prophylaxis used for this patient population.

Cefepime versus ceftazidime as empiric therapy for fever in neutropenic patients with cancer.

OBJECTIVE: To compare the efficacies of cefepime and ceftazidime as empiric therapy during the management of fever in cancer patients with chemotherapy-induced neutropenia. METHODS: A prospective, double-blind, randomized study of cefepime 2 g every eight hours and ceftazidime 2 g every eight hours was performed in 276 adult neutropenic (absolute neutrophil count < 500/mm3) cancer patients with fever. RESULTS: Median duration of neutropenia was five days. Sixty-one percent (n = 188) of the patients were evaluable. Treatment was successful in 57% (58/101) of cefepime-treated patients and 60% (52/87) of ceftazidime-treated patients (95% CI -18 to 12; p = 0.77). Bacteremic clearance occurred in 71% (12/17) of cefepime-treated patients and 40% (6/15) of ceftazidime-treated patients (p = 0.3). Both drugs were well tolerated. CONCLUSIONS: Cefepime appears to be as effective as ceftazidime in the initial treatment of febrile episodes in adult cancer patients with chemotherapy-associated neutropenia of modest duration.

Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Adults and children in the United States get two to six colds per year. Evidence that zinc is effective therapy for colds is inconsistent. OBJECTIVE: To test the efficacy of zinc acetate lozenges in reducing the duration of symptoms of the common cold. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Detroit Medical Center, Detroit, Michigan. PATIENTS: 50 ambulatory volunteers recruited within 24 hours of developing symptoms of the common cold. INTERVENTION: Participants took one lozenge containing 12.8 mg of zinc acetate or placebo every 2 to 3 hours while awake as long as they had cold symptoms. MEASUREMENTS: Subjective symptom scores for sore throat, nasal discharge, nasal congestion, sneezing, cough, scratchy throat, hoarseness, muscle ache, fever, and headache were recorded daily for 12 days. Plasma zinc and proinflammatory cytokine levels were measured on day 1 and after participants were well. RESULTS: Forty-eight participants completed the study (25 in the zinc group and 23 in the placebo group). Compared with the placebo group, the zinc group had shorter mean overall duration of cold symptoms (4.5 vs. 8.1 days), cough (3.1 [95% CI, 2.1 to 4.1] vs. 6.3 [CI, 4.9 to 7.7] days), and nasal discharge (4.1 [CI, 3.3 to 4.9] vs. 5.8 [CI, 4.3 to 7.3] days) and decreased total severity scores for all symptoms (P < 0.002, test for treatment x time interaction). Mean changes in soluble interleukin-1 receptor antagonist level differed nonsignificantly between the zinc group and the placebo group (difference between changes, -89.4 pg/mL [CI, -243.6 to -64.8 pg/mL]). CONCLUSION: Administration of zinc lozenges was associated with reduced duration and severity of cold symptoms, especially cough. Improvement in clinical symptoms with zinc treatment may be related to a decrease in proinflammatory cytokine levels; however, in this study, the observed differences between changes in cytokine levels in zinc and placebo recipients were not significant.

Proton-pumping-ATPase-targeted antifungal activity of a novel conjugated styryl ketone.

NC1175 (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinyle ne]-1- ethyl-4-piperidinol hydrochloride) is a novel thiol-blocking conjugated styryl ketone that exhibits activity against a wide spectrum of pathogenic fungi. Incubation of NC1175 with various concentrations of cysteine and glutathione eliminated its antifungal activity in a concentration-dependent fashion. Since NC1175 is a lipophilic compound that has the potential to interact with cytoplasmic membrane components, we examined its effect on the membrane-located proton-translocating ATPase (H(+)-ATPase) of yeast (Candida albicans, Candida krusei, Candida guilliermondii, Candida glabrata, and Saccharomyces cerevisiae) and Aspergillus (Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, and Aspergillus nidulans) species. The glucose-induced acidification of external medium due to H(+)-ATPase-mediated expulsion of intracellular protons by these fungi was measured in the presence of several concentrations of the drug. NC1175 (12.5 to 50 microM) inhibited acidification of external medium by Candida, Saccharomyces, and Aspergillus species in a concentration-dependent manner. Vanadate-inhibited hydrolysis of ATP by membrane fractions of C. albicans was completely inhibited by 50 microM NC1175, suggesting that the target of action of NC1175 in these fungi may include H(+)-ATPase.

In-vitro and in-vivo susceptibility of Aspergillus fumigatus to a novel conjugated styryl ketone.

We investigated the in-vitro and in-vivo susceptibility of Aspergillus fumigatus to the novel conjugated styryl ketone NC1175 and the results were compared with those obtained for amphotericin B and itraconazole. All 20 clinical isolates of A. fumigatus examined were susceptible to NC1175 (MIC = 5.54 +/- 2.48 mg/L; range 2.92-11.68 mg/L), and the minimum lethal concentration (MLC) was only twice the MIC, suggesting that NC1175 is fungicidal. The mean MIC values of amphotericin B (1.22 +/- 0.58 mg/L; range 0.5-4 mg/L) and itraconazole (0.37 +/- 0.11 mg/L; range 0.125-0.5 mg/L) were approximately nine- and 22-fold, respectively, lower than that of NC1175. Both amphotericin B-resistant (n = 18) and itraconazole-resistant (n = 28) isolates of A. fumigatus were as susceptible to NC1175 as amphotericin B-, and itraconazole-susceptible isolates. Kill curve experiments revealed that NC1175 at 23.35 mg/L (approximately four times the MIC) killed > or = 99% of conidia within 24 h of exposure to the drug. The in-vivo susceptibility of A. fumigatus to NC1175 was investigated using a murine pulmonary aspergillosis model. Treatment of infected mice with amphotericin B or NC1175 did not result in significant improvement of the mean survival (amphotericin B, 7.05 +/- 0.07 days; NC1175, 6.65 +/- 1.25 days) of the animals compared with that of the placebo group (7.21 +/- 1.20 days). However, semiquantitative organ culture revealed that clearance of A. fumigatus occurred in 16.6%, 50% and 66.6% of the mice treated with placebo, NC1175 and amphotericin B, respectively (P value for the control and the treated groups <0.01). These results suggest that NC1175 has in-vivo and in-vitro activity against A. fumigatus and can be used as a prototypic molecule for further development as an antifungal agent.

Disseminated toxoplasmosis in marrow recipients: a report of three cases and a review of the literature. Bone Marrow Transplant Team.

Toxoplasma infection following bone marrow transplantation (BMT) is infrequently reported. We report three cases of disseminated toxoplasmosis in BMT recipients documented during an 8-year period at our institution: one after an unrelated marrow transplant in a toxoplasma-seronegative patient, the second complicating syngeneic marrow transplantation, and the third following allogeneic, related BMT. The disease is extremely rare in seronegative patients and has not been previously reported in syngeneic recipients. Toxoplasmosis was diagnosed at autopsy in two of the three cases. We also present a review of all reported cases of toxoplasmosis in marrow recipients from North American and other BMT centers. Heightened awareness of the occurrence of toxoplasmosis in marrow recipients and early diagnostic/therapeutic measures are needed for a better outcome.