Pulmonary fungal infections in patients with acute myeloid leukaemia: is it the time to revise the radiological diagnostic criteria?

The definition of pulmonary fungal infections (PFI) according to the EORTC-MSG criteria may lack diagnostic sensitivity due to the possible presentation of PFI with different radiological pictures. We evaluated the hypothesis to apply less restrictive radiological criteria to define PFI in patients with acute myeloid leukaemia (AML) submitted to chemotherapy. Overall, 73 consecutive episodes of pulmonary infiltrates associated to positive serum galactomannan test or fungal isolation or galactomannan detection from respiratory specimens were considered. CT scans acquired at the onset of symptoms (time-0) and within 4 weeks (time-1) were analysed to identify specific (group A) or aspecific radiological signs (group B). Pulmonary infiltrates fulfilled the EORTC-MSG criteria in 49 patients (group A), whereas in 24 patients (group B) they did not reach the criteria due to aspecific CT findings at time-0. Eleven of 21 (52.4%) patients of the group B evaluable for the evolution of the radiological findings fulfilled EORTC-MSG criteria at time-1. All the analysed clinical and mycological characteristics, response to antifungal therapy and survival were comparable in the two groups. Our study seems to confirm the possibility to extend the radiological suspicion of PFI to less restrictive chest CT findings when supported by microbiological criteria in high-risk haematological patients

Diagnosis of invasive fungal infections

A proper diagnostic strategy of invasive fungal infections (IFI) is a very important component in the management of infectious complications in hematological patients. A good diagnostic approach should be adapted to the patient in relation to the underlying disease, stage of disease, localization of infection and immune status. None of the diagnostic markers can be entirely adopted for medical decision making, and sometimes it's useful to use the combination of several microbiological tests.The diagnosis of IFI must therefore have a multidisciplinary approach that includes clinical suspicion, microbiological results and radiological evidence

Microbiological diagnostics of fungal infections

Laboratory tests for the detection of fungal infections are easy to perform. The main obstacle to a correct diagnosis is the correlation between the laboratory findings and the clinical diagnosis. Among pediatric patients, the most common fungal pathogen is Candida. The detection of fungal colonization may be performed through the use of chromogenic culture media, which allows also the identification of Candida subspecies, from which pathogenicity depends. In neonatology, thistest often drives the decision to begin a empiric therapy; in this regard, a close cooperation between microbiologists and clinicians is highly recommended. Blood culture, if positive, is a strong confirmation of fungal infection; however, its low sensitivity results in a high percentage of false negatives, thus decreasing its reliability. Molecular diagnostics is still under evaluation, whereas the detection of some fungal antigens, such as β-D-glucan, galactomannan, mannoprotein, and cryptococcal antigen in the serum is used for adults, but still under evaluations for pediatric patients

Why MIC matters? Microbiologists vs. clinicians

Several mechanisms of resistance may interfere with the patients’ healing from a fungal infection. However, in premature children fungi are generally susceptible to antifungal agents, except in case of vertical transmission from the mother. In vitro sensitivity tests have been recently harmonized between American and European standards, after years of unhomogeneity: to date, the interpretation of epidemiological cut-off of wild-type population and clinical cut-off are common, and are often updated. Sensitivity tests are difficult to perform, but luckily new commercial tests approvedby FDA are available. Sometimes, knowing the intrinsic sensitivities and resistances of every fungal species and subspecies may be enough in the clinical practice, since few resistances are acquired

Invasive Candida Infections in Patients With Haematological Malignancies and Hematopoietic Stem Cell Transplant Recipients: Current Epidemiology and Therapeutic Options.

In the last decades, the global epidemiological impact of invasive candidiasis (IC) in patients with hematologic malignancies (HM) and in hematopoietic stem cell transplant (HSCT) recipients has decreased and the incidence of invasive aspergillosis exceeded that of Candida infections. The use of prevention strategies, first of all antifungal prophylaxis with triazoles, contributed to the reduction of IC in these populations as demonstrated by several epidemiological studies. However, relatively little is known about the current epidemiological patterns of IC in HM and HSCT populations, because recent epidemiological data almost exclusively derive from retrospective experiences and few prospective data are available. Several prospective, controlled studies in the prophylaxis of invasive fungal diseases have been conducted in both the HM and HSCT setting. On the contrary, most of the prospective controlled trials that demonstrated the efficacy of the antifungal drugs echinocandins and voriconazole in the treatment of candidemia and invasive candidiasis mainly involved patients with underlying conditions other than HM or HSCT. For these reasons, international guidelines provided specific indications for the prophylaxis strategies in HM and HSCT patients, whereas the recommendations on therapy of documented Candida infections are based on the results observed in the general population and should be considered with caution

Genetic variability among Blastoschizomyces capitatus isolates from different clinical sources.

Sixteen clinical isolates and nine ATCC reference strains of Blastoschizomyces capitatus were analysed genetically, examined for the cellobiose, arbutin and salicin assimilation and tested for the aspartyl-proteinase secretion. The restriction endonuclease analysis (REA) with HpaII and HinfI enzymes and the electrophoretic karyotype (EK) were investigated. Both the restriction enzymes revealed two groups (I, II) constituted by the same isolates: 17 isolates (68%) in group I and 8 (32%) in group II. The EK analysis revealed sixteen groups. These data prompts for a genetic variability of the isolates of Blastoschizomyces capitatus and their account in two distinct genetic groups as suggested by REA. This grouping was confirmed by examing the utilisation of cellobiose, arbutin and salicin. The tests for secretory aspartyl proteinase (Sap) were positive only for three isolates, suggesting a marginal role of this specific enzyme in pathogenesis for these isolates

Low Incidence Rate of Opportunistic and Viral Infections During Imatinib Treatment in Chronic Myeloid Leukemia Patients in Early and Late Chronic Phase.

<!--StartFragment--> <p class="MsoNormal" style="text-align: justify; line-height: 150%;"><span style="font-family: Arial; mso-ansi-language: EN-GB;" lang="EN-GB">Background: Imatinib has become first line therapy in chronic myeloid leukemia patients. Little is known about the infective consequences during the treatment with this drug in large series of chronic phase patients. </span></p> <p class="MsoNormal" style="text-align: justify; line-height: 150%;"><span style="font-family: Arial; mso-ansi-language: EN-GB;" lang="EN-GB">Material and methods: From January 2001 to September 2006 we treated with imatinib 250 patients in first line (early CP) or after interferon failure (late CP), out of clinical trials and recorded all the bacterial and viral infections occurred.</span></p> <p class="MsoNormal" style="text-align: justify; line-height: 150%;"><span style="font-family: Arial; mso-ansi-language: EN-GB;" lang="EN-GB">Results: We recorded a similar incidence of bacterial and viral infections both in first line and late CP patients (respectively, 16% and 13%) during 3.5 years of follow-up. Analysis of presenting features predisposing to infections revealed differences only in late CP patients, with elevated percentage of high Sokal risk patients and a more longer median time from diagnosis to start of imatinib.</span></p> <p class="MsoNormal" style="text-align: justify; line-height: 150%;"><span style="font-family: Arial; mso-ansi-language: EN-GB;" lang="EN-GB">Conclusions: Opportunistic infections and reactivation of Herpes Zoster are observed during imatinib therapy at very low incidence.</span></p> <!--EndFragment--&gt

Invasive Fungal Infections in Patients with Hematologic Malignancies (Aurora Project): Lights and Shadows During 18-Months Surveillance

The aim of this multicenter prospective study was to evaluate the incidence of invasive fungal infections (IFIs) in adult and pediatric patients with hematologic malignancies, involving nine nosocomial facilities in Southern Italy over a period of 18 months. Furthermore, results of an environmental microbial surveillance routinely carried out in some of the enrolled hospitals are reported. A total of 589 onco-hematological patients were enrolled and 27 IFIs were documented. The main infections were caused by yeasts, more than filamentous fungi (overall incidence of 2.7% and 1.9%, respectively). The yeasts were mainly represented by Candida spp. (87.5%), all isolated by blood cultures; C. parapsilosis was the most common species. Among mould infections, the most frequent site was the lung, with regard to aspergillosis (81.8%). In six of the 10 patients with suspected aspergillosis, the diagnosis was made by the detection of galactomannan and (1,3)-β-d-glucan antigens. The microbiological surveillance carried out on 156 air, 312 water and 312 surface samples revealed low environmental contamination: Alternaria alternata was the only fungus isolated from two surface samples. Our data, especially the low occurrence of filamentous fungi, suggest a particular local epidemiology. Further studies are needed to confirm this microbiological trend in onco-hematological patients in Southern Italy, the results of which might be helpful to improve the management of these patients