[Generation of Antibiotic Tolerant Bacterial Persisters in Immunocompromized Patients with Hematologic and Malignant Diseases: A New Problem of Health-Care Associated Infections]

BACKGROUND

Antibiotic tolerance (AT) represents one of the causes of the phenomenon of antibiotic resistance that allows escape of non-replicating metabolically inert microorganisms (persisters) from any antibiotics attack because molecular targets of antibiotics are lacking thereby creating the potential for chronic infections.

AIMS

Determine the heterogeneity of the strains of opportunistic pathogens E. coli and P. aeruginosa isolates from children with hematologic malignancies containing bacterial persisters that cause the AT phenomenon.

METHODS

Children with hematological malignancies were divided into 2 groups according to the intensity of antibiotic treatment of infectious complications. Ciprofloxacin-induced persisters were quantitatively determined in the biological materials obtained from sick children.

RESULTS

Within the clinical isolates of E. coli and P. aeruginosa, about a third of the strains belong to high-persisting. The numbers of persistent forms of bacteria did not correlate with a minimal inhibitory concentration values ciprofloxacin (r=0.148, n=25, p>0.05). Interestingly, higher level of formation of persistent E. coli and P. aeruginosa, is associated with higher frequencies of infection attacks, massive antibiotic use and unfavorable course of the disease in children.

CONCLUSIONS

Therefore, detecting the persistent forms of bacterial pathogens including those associated with the health-care associated infection, specifically, in immunocompromised patients, should be included into the contemporary algorithms of microbiological observation and monitoring of patients and intrahospital environment.

NOCARDIA BEIJINGENSIS PSOAS ABSCESS AND SUBCUTANEOUS PHAEOHYPHOMYCOSIS CAUSED BY PHAEOACREMONIUM PARASITICUM IN A RENAL TRANSPLANT RECIPIENT: THE FIRST CASE REPORT IN THAILAND

We describe the first case of a psoas muscle abscess caused by Nocardia beijingensis and subcutaneous phaeohyphomycosis caused by Phaeoacremonium parasiticum in a renal transplant recipient. The patient was treated for nocardiosis with percutaneous drainage and intravenous trimethoprim/sulfamethoxazole (TMP/SMX) combined with imipenem for 2 weeks, followed by a 4-week course of intravenous TMP/SMX and then oral TMP/SMX. During hospitalization for the psoas muscle abscess the patient developed cellulitis with subcutaneous nodules of his right leg. Skin biopsy and cultures revealed a dematiaceous mold, subsequently identified as P. parasiticum by DNA sequencing. The subcutaneous phaeohyphomycosis was treated with surgical drainage and liposomal amphotericin B for 4 weeks followed by a combination of itraconazole and terbinafine. The patient gradually improved and was discharged home after 18 weeks of hospitalization.

[INFECTIONS IN THE TRANSPLANT PATIENT]

Infections in the transplant patient are common. There are infections related to the host (recipient), those related to the graft and the related donor. Infectious risk factors depend on the history of the underlying disease of the transplanted organ, the donor, the immunosuppressive treatment. All pathogens, bacteria, viruses, fungi and parasites are possible but their frequency varies according to the transplanted organ, the selected immunosuppressive therapy and prophylaxis. Indeed, it is important to detect and treat latent infections in pro-transplant and prevent post-transplant infections by lifestyle and dietary measures, vaccinations, intraoperative antibiotic, antiviral, antifugal, antiparasitic treatments according graft and a variable length depending on the immunosuppression and donor-recipient status.

Efficacy and Safety of an Everolimus- vs. a Mycophenolate Mofetil-Based Regimen in Pediatric Renal Transplant Recipients

Introduction

Data on the efficacy and safety of everolimus in pediatric renal transplantation compared to other immunosuppressive regimens are scarce.

Patients/Methods

We therefore performed a multicenter, observational, matched cohort study over 4 years post-transplant in 35 patients on everolimus plus low-dose cyclosporine, who were matched (1:2) with a control group of 70 children receiving a standard-dose calcineurin-inhibitor- and mycophenolate mofetil-based regimen.

Results

Corticosteroids were withdrawn in 83% in the everolimus vs. 39% in the control group (p<0.001). Patient and graft survival were comparable. The rate of biopsy-proven acute rejection episodes Banff score ≥ IA during the first year post-transplant was 6% in the everolimus vs. 13% in the control group (p = 0.23). The rate of de novo donor-specific HLA antibodies (11% in everolimus, 18% in controls) was comparable (p = 0.55). At 4 years post-transplant, mean eGFR in the everolimus group was 56±33 ml/min per 1.73 m² vs. 63±22 ml/min per 1.73 m² in the control group (p = 0.14). Everolimus therapy was associated with less BK polyomavirus replication (3% vs. 17% in controls; p = 0.04), but with a higher percentage of arterial hypertension and more hyperlipidemia (p<0.001).

Conclusion

In pediatric renal transplantation, an everolimus-based regimen with low-dose cyclosporine yields comparable four year results as a standard regimen, but with a different side effect profile.

Screening and Monitoring for Infectious Complications When Immunosuppressive Agents Are Studied in the Treatment of Autoimmune Disorders

Significant progress has been made in the development, investigation, and clinical application of immunosuppressive agents to treat a variety of autoimmune disorders. The expansion of clinical applications of these new agents requires the performance of large multicenter clinical trials. These large clinical trials are particularly important as one considers these agents for the treatment of type 1 diabetes, which although autoimmune in its pathogenesis, is not classically treated as an autoimmune disorder. Although these agents hold promise for amelioration or cure of this disease, they have the potential to facilitate infectious complications. There are limited data regarding the prospective assessment of infectious risks with these agents in trials of this nature. Pediatric subjects may be at greater risk due to the higher likelihood of primary infection. A subgroup of experts associated with TrialNet (a National Institutes of Health [NIH]-funded Type 1 diabetes mellitus research network) with expertise in infectious diseases, immunology, and diagnostics developed an approach for screening and monitoring of immunosuppression-associated infections for prospective use in clinical trials. The goals of these recommendations are to provide a structured approach to monitor for infections, to identify specific laboratory testing and surveillance methods, and to consider therapies for treatment of these potential complications. Prospective evaluations of these infectious risks allow for greater scientific rigor in the evaluation of risk, which must be balanced with the potential benefits of these therapies. Our experience supports an important role for investigators with expertise in infections in immunocompromised individuals in protocol development of immunosuppressive trials in type 1diabetes and potentially other autoimmune diseases.

The Impact of Opportunistic Infections on Clinical Outcome and Healthcare Resource Uses for Adult T Cell Leukaemia

We examined the impact of opportunistic infections on in-hospital mortality, hospital length of stay (LOS), and the total cost (TC) among adult T-cell leukaemia (ATL) patients. In this retrospective cohort study, we identified 3712 patients with ATL using national hospital administrative data. Analysed opportunistic infections included Aspergillus spp., Candida spp., cytomegalovirus (CMV), herpes simplex virus (HSV), pneumocystis pneumonia (PCP), tuberculosis, varicella zoster virus (VZV), Cryptococcus spp., nontuberculous mycobacteria, and Strongyloides spp. Multilevel logistic regression analysis for in-hospital mortality and a multilevel linear regression analysis for LOS and TC were employed to determine the impact of opportunistic infections on clinical outcomes and healthcare resources. We found ATL patients infected with CMV had significantly higher in-hospital mortality (adjusted odds ratio (AOR) 2.29 [1.50-3.49] p < 0.001), longer LOS (coefficient (B): 0.13 [0.06-0.20] p < 0.001) and higher TC (B: 0.25 [0.17-0.32] p < 0.001) than those without CMV. Those with CAN and PCP were associated with a lower in-hospital mortality rate (AOR 0.72 [0.53-0.98] p = 0.035 and 0.54[0.41-0.73] p < 0.001, respectively) than their infections. VZV was associated with longer LOS (B: 0.13 [0.06-0.19] p < 0.001), while aspergillosis, HSV, or VZV infections were associated with higher TC (B: 0.16 [0.07-0.24] p < 0.001, 0.12 [0.02-0.23] p = 0.025, and 0.17 [0.10-0.24] p < 0.001, respectively). Our findings reveal that CMV infection is a major determinant of poor prognosis in patients affected by ATL.

Rare angioinvasive fungal infection in association with leukemia cutis

Leukemia cutis (LC) is characterized by the infiltration of malignant neoplastic leukocytes or their precursors into the skin and is most often seen in conjunction with systemic leukemia. Patients with LC frequently are in a relative or absolute immunocompromised state. We report the case of a 52-year-old man with primary refractory acute myelogenous leukemia (AML) following allogeneic stem cell transplant (SCT) who presented with a progressive reddish purple nodule with surrounding erythema and central necrosis in the setting of leukocytosis and possible fungal pneumonia. Histopathologic examination revealed an ulcerated dense diffuse dermal infiltrate of large atypical lymphocytes consistent with LC and septate hyphae with acute-angle branching in the dermal blood vessels. Cultures from a biopsied lesion grew Paecilomyces species, a rare but emerging opportunistic infection, despite the patient being on antifungal prophylaxis. This novel report of a rare angioinvasive infection occurring within a lesion of LC supports the need to maintain a high index of suspicion for invasive infection in patients with hematologic malignancy, even those on antifungal prophylaxis.

Adverse effects of low-dose systemic cyclosporine therapy in high-risk penetrating keratoplasty

PURPOSE

The purpose of this study was to investigate the adverse effects of low-dose oral cyclosporine (CsA) therapy following high-risk corneal transplantation.

METHODS

The medical records from 88 subjects who had undergone high-risk penetrating keratoplasties and had been administered oral CsA were retrospectively analyzed. High risk was defined as a history of graft rejection, three or more quadrants of vascularization, or the presence or history of intraocular inflammation. An initial CsA dose of 3-5 mg/kg per day was given for 3-7 days, followed by 2.5-3.5 mg/kg per day for approximately 1 month. The concentration of CsA was maintained at the target trough level of 120-150 ng/ml for at least 6 months or until serious complications developed. The relationship between the cumulative dose and duration of CsA administration and the adverse systemic effects, including the frequency of herpes keratitis, was evaluated. The incidence of herpes keratitis in the study subjects was compared with the incidence in 185 patients who had not received CsA therapy following penetrating keratoplasty.

RESULTS

The mean survival time of the grafts was 33.6 months. Adverse effects occurred in 81.8 % of subjects. Hypertension, elevated liver enzyme levels, elevated serum creatinine level, and decreased absolute neutrophil count (ANC) were observed in 14.8, 6.8, 5.7, and 5.7 % of subjects, respectively. Simvastatin-induced rhabdomyolysis also developed in one case. Some patients exhibited minor complications, with gastrointestinal problems and hypertrichosis recorded in 5.7 and 3.4 % of subjects, respectively. Hypertension and hepatotoxicity most frequently occurred after 4 to 8 weeks of medication, while ANC decrease and nephrotoxicity generally developed after 24 weeks of treatment, with incidence related to the cumulative dose. Herpes keratitis occurred more frequently (31.8 %) in the CsA-treated subjects than in subjects that did not receive CsA therapy (p = 0.005). Most of the adverse effects were reversed after discontinuation of CsA therapy.

CONCLUSION

The results of this study suggest that low-dose oral CsA therapy may induce various adverse effects, the most common of which are herpes keratitis and hypertension.

Evaluation of invasive aspergillosis risk of immunocompromised patients alternatively hospitalized in hematology intensive care unit and at home

Contrary to hospital exposure, little is known about the indoor fungal exposure of hematology patients at home. The aim of our study was to investigate the mold exposure of hematology patients both at home and at hospital to assess their invasive aspergillosis (IA) risk. Fungal exposure was assessed by quantifying opportunistic molds at hospital during hospitalization and in homes of 53 hematology patients. IA was diagnosed in 13 of 53 patients and invasive fungal infection (IFI) in one patient. In hospital, no opportunistic species, or low levels of opportunistic species, were found in 98% of weekly controls. Only 2% of hematology intensive care unit (ICU) controls showed a high level of Aspergillus fumigatus spores in corridor air. Five patients IA were hospitalized during these periods. Seven dwellings of 53 (5/14 dwellings of patients with IA/IFI and 2/39 dwellings of non-IA patients) had a percentage of A. fumigatus and Aspergillus flavus to total mold (significant predictor variable of IA/IFI in our study, general linear model, P-value = 0.02) as high as 15%. Maintaining a 'zero Aspergillus' goal at hospital is essential, and establishing specific and individually opportunistic mold monitoring at home could help to further reduce the IA risk through continuous surveillance.

PRACTICAL IMPLICATIONS

This study emphasizes the fact that preventive measures should not be aimed only at the hospital setting: among patients diagnosed with invasive aspergillosis/invasive fungal infection (IA/IFI), 5 of 14 (36%) were exposed to opportunistic fungal species at home exclusively. Moreover, four of these five patients were living in homes having the highest percentage of Aspergillus fumigatus and Aspergillus flavus (>15%), one of which had 48% of A. fumigatus. Therefore, our work supports the need for a counselor to carry out an environmental survey in patients’ homes.

Status of PI3K/Akt/mTOR pathway inhibitors in lymphoma

The phosphatidylinositol-3-kinase (PI3K) pathway is well known to regulate a wide variety of essential cellular functions, including glucose metabolism, translational regulation of protein synthesis, cell proliferation, apoptosis, and survival. Aberrations in the PI3K pathway are among the most frequently observed in cancer, and include amplifications, rearrangements, mutations, and loss of regulators. As a net result of these anomalies, the PI3K pathway is activated in many malignancies, including in Hodgkin and non-Hodgkin lymphomas, and yields a competitive growth and survival advantage, increased metastatic ability, and resistance to conventional therapy. Numerous inhibitors targeting various nodes in the PI3K pathway are undergoing clinical development, and their current status in lymphoma will be the focus of this review.

Prevention and management of cytomegalovirus infection in solid-organ transplantation

Cytomegalovirus (CMV) is the most common opportunistic viral infection to occur following solid-organ transplantation. This review will discuss the current strategies of management of CMV in solid-organ transplantation and their challenges. There are two principal approaches for preventing CMV disease in recipients of solid-organ transplants: prophylactic and pre-emptive. Ganciclovir is the most studied and used antiviral for both treatment and prevention, and is the first-line treatment for CMV infection and CMV disease in transplant recipients. There is no consensus regarding the most appropriate prevention method and the approach to CMV disease prevention differs among transplantation centers owing to the paucity of data comparing the two strategies head-to-head. Currently, the recommended treatment for CMV disease is intravenous ganciclovir.

[Alveolar proteinosis: a cause of immunodeficiency]

Alveolar proteinosis is a rare disease, characterized by accumulation of surfactant in alveoli. Various forms have been identified (congenital, secondary or auto-immune). Treatment is to be reserved for patients that experience moderate to severe symptoms. It requires whole lung lavages, in order to clear the alveoli from the proteinaceous material. Macrophages dysfunction plays a crucial role in the development of the disease and causes immunodeficiency, which in turn can promote opportunistic infections, in patients a priori thought to be immunocompetent.

Postinfectious Guillain-Barre syndrome in a patient with methimazole-induced agranulocytosis

Both Graves disease and Guillain-Barre syndrome (GBS) are autoimmune disorders caused by impaired self-tolerance mechanisms and triggered by interactions between genetic and environmental factors. GBS in patients who suffer from other autoimmune diseases is rarely reported, and the development of postinfectious GBS in a patient with Graves disease has not been previously reported in the literature. Herein, we report a patient with Graves disease who developed postinfectious GBS during a course of methimazole-induced agranulocytosis.

Hepatitis B reactivation in patient with non-Hodgkin's lymphoma receiving rituximab-based chemotherapy: need for education and attention

Hepatitis B reactivation can occur in patients with inactive chronic hepatitis B receiving rituximab treatment. Therefore, hepatitis B virus (HBV) screening is recommended in patients planned for chemotherapy and antiviral prophylaxis needs to be started prior to initiating the treatment in patients with evidence of HBV infection. We describe a 58-year-old African American man with history of chronic hepatitis B who developed severe (HBV) reactivation while receiving rituximab treatment for Non-Hodgkin's lymphoma (NHL). The report highlights that greater education is needed amongst clinicians regarding risk of HBV reactivation while receiving chemotherapy, particularly with rituximab-based treatment.

Immune Reconstitution and Early Infectious Complications Following Nonmyeloablative Hematopoietic Stem Cell Transplantation

Non-myeloablative stem cell transplantation (NMT) has been increasingly used in compromised patients who would otherwise have been unable to undergo allotransplant. There is little understanding of the kinetics of immune reconstitution and its influence on infective complications following NMT. The aim of present study was to evaluate lymphocyte subset reconstitution over the first 12 months post-transplant in 15 adult patients receiving NMT with comparison to that of 30 patients grafted with a conventional hemopoietic stem cell transplantation (HSCT). NMT recipients were conditioned with fludarabine-based conditioning regimens. Peripheral blood stem cell (PBSC) was the source of stem cells in 13 NMT recipients and in 24 conventional HSCT recipients. Absolute numbers of helper (CD4+) T cells, naive (CD4+ CD45RA+) and memory (CD4+ CD45RO+) T cells as well as suppressor (CD8+) T cells, CD19+ B cells and NK cells were comparable in the two groups at all time points after transplantation. A median value of 200 CD4+ T cells/microl was achieved at 2 months post-transplant by the NMT and HSCT recipients. The CD4:CD8 ratio remained severely depressed throughout the study period. Almost all CD4+ lymphocytes expressed CD45RO antigen in the both groups of patients B lymphocytes showed low counts throughout the entire study period in both groups. Bacteremia and CMV antigenemia occurred respectively in 13 and 36% of the patients in the NMT group and in 15 and 39% of the patients in the HSCT group. Our preliminary data indicate that patients receiving a NMT have a lymphocyte reconstitution similar to that observed in patients who received a conventional HSCT. The incidence of bacteremia and CMV infection were not significantly different between the groups. Nevertheless, due to the small sample size, these results should be considered suggestive rather than definitive.

[Infectious events during the first year of treatment with an antagonist of the tumor necrosis factor]

OBJECTIVE

To assess the incidence of severe infections in patients treated with anti-TNF-??drugs, during the first year of treatment with these drugs.

MATERIALS AND METHOD

Retrospective observational study carried out at a general hospital from a sample of patients receiving their first anti-TNF-??drug, according to approved indications, to treat a rheumatic disease. Each patient follow-up lasted for 2 years: the year before receiving the drug and the year after starting on this therapy. We considered those severe infectious events requiring hospital admission. A cohort study was performed before-after. The incidence rates of number of events (infections) per 100,000 inhabitants/year for the first treatment year and the previous year (control period) were calculated. The relative risk was calculated.

RESULTS

We included 196 patients. Twelve severe infectious events were recorded during the first treatment year, with a relative risk of 2.4. The biological drug most frequently associated to infection was Adalimumab. All patients having an infection had been previously or concomitantly treated with Methotrexate, and 90.6% with glucocorticosteroids. The main location of the infection was the respiratory system (58.3%), and the gram-positive microorganisms were the most frequent (58.3%).

CONCLUSIONS

The use of anti-TNF-??drugs, and mainly Adalimumab, represents a risk factor for suffering severe infections, mainly at the respiratory tract, produced by gram-positive microorganisms. The use of immunosuppressive drugs such as Methotrexate and glucocorticosteroids seems to increase the risk for such events.