Should possible recurrence of disease contraindicate liver transplantation in patients with end-stage alveolar echinococcosis? A 20-year follow-up study

Liver transplantation (LT) is currently contraindicated in patients with residual or metastatic alveolar echinococcosis (AE) lesions. We evaluated the long-term course of such patients who underwent LT and were subsequently treated with benzimidazoles. Clinical, imaging, serological, and therapeutic data were collected from 5 patients with residual/recurrent AE lesions who survived for more than 15 years. Since 2004, [(18) F]-2-fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) images were available, and the levels of serum antibodies (Abs) against Echinococcus multilocularis-recombinant antigens were evaluated. Median survival time after LT was 21 years. These patients were from a prospective cohort of 23 patients with AE who underwent LT: 5 of 8 patients with residual/recurrent AE and 4 of 9 patients without residual/recurrent AE were alive in September 2009. High doses of immunosuppressive drugs, the late introduction of therapy with benzimidazoles, its withdrawal due to side effects, and nonadherence to this therapy adversely affected the prognosis. Anti-Em2(plus) and anti-rEm18 Ab levels and standard FDG-PET enabled the efficacy of therapy on the growth of EA lesions to be assessed. However, meaningful variations in Ab levels were observed below diagnostic cutoff values; and in monitoring AE lesions, images of FDG uptake taken 3 hours after its injection were more sensitive than images obtained 1 hour after its injection. In conclusion, benzimidazoles can control residual/recurrent AE lesions after LT. Using anti-rEm18 or anti-Em2(plus) Ab levels and the delayed acquisition of FDG-PET images can improve the functional assessment of disease activity. The potential recurrence of disease, especially in patients with residual or metastatic AE lesions, should not be regarded as a contraindication to LT when AE is considered to be lethal in the short term.

Immuno-reactive proteins from Mycobacterium immunogenum useful for serodiagnosis of metalworking fluid hypersensitivity pneumonitis

Metalworking fluid-associated hypersensitivity pneumonitis (MWF-HP) is a pulmonary disease caused by inhaling microorganisms present in the metalworking fluids used in the industrial sector. Mycobacterium immunogenum is the main etiological agent. Among the clinical, radiological and biological tools used for diagnosis, serological tests are important. The aim of this study was to identify immunogenic proteins in M. immunogenum and to use recombinant antigens for serological diagnosis of MWF-HP. Immunogenic proteins were detected by two-dimensional Western blot and candidate proteins were identified by mass spectrometry. Recombinant antigens were expressed in Escherichia coli and tested by enzyme-linked immunosorbent assay (ELISA) with the sera of 14 subjects with MWF-HP and 12 asymptomatic controls exposed to M. immunogenum. From the 350 spots visualized by two-dimensional gel electrophoresis with M. immunogenum extract, 6 immunogenic proteins were selected to be expressed as recombinant antigens. Acyl-CoA dehydrogenase antigen allowed for the best discrimination of MWF-HP cases against controls with an area under the receiver operating characteristics (ROC) curve of 0.930 (95% CI=0.820-1), a sensitivity of 100% and a specificity of 83% for the optimum threshold. Other recombinant antigens correspond to acyl-CoA dehydrogenase FadE, cytosol aminopeptidase, dihydrolipoyl dehydrogenase, serine hydroxymethyltransferase and superoxide dismutase. This is the first time that recombinant antigens have been used for the serodiagnosis of hypersensitivity pneumonitis. The availability of recombinant antigens makes it possible to develop standardized serological tests which in turn could simplify diagnosis, thus making it less invasive.

Hypersensitivity pneumonitis and metalworking fluids contaminated by mycobacteria

Metalworking fluids (MWF) are responsible for hypersensitivity pneumonitis (HP). The aim of the present study was to identify the antigen (Ag) responsible for MWF-associated HP, and to optimise serological diagnosis by definition of a threshold allowing discrimination between HP patients and asymptomatic exposed workers. 13 patients, who were workers at a car engine manufacturing plant, were suspected of MWF-associated HP. Microbial analysis of 83 used MWFs was carried out. Sera from 13 MWF-associated HP patients, 12 asymptomatic exposed workers and 18 healthy unexposed controls were tested to determine their immunological responses to three Ags, including Mycobacterium immunogenum. M. immunogenum was identified in 40% of used fluids by culture and confirmed by DNA sequencing. The threshold for differentiating MWF-associated HP patients from asymptomatic exposed workers was five arcs of precipitation (sensitivity 77% and specificity 92%), as determined by electrosyneresis (ES). Using ELISA methods with protein extract from M. immunogenum, a threshold leading to 92% sensitivity and 100% specificity was established. The detection of specific antibodies against M. immunogenum Ag at high levels in case sera suggests that M. immunogenum-contaminated MWF is responsible for MWF-associated HP. To discriminate MWF-associated HP patients from asymptomatic exposed workers, we suggest a five-arc threshold for ES and a 1.6-AU threshold for ELISA methods.

False-positive Aspergillus real-time PCR assay due to a nutritional supplement in a bone marrow transplant recipient with GVH disease

PCR screening for circulating DNA, especially when combined with antigen testing, has shown promise for the definitive diagnosis of invasive aspergillosis. False positives for Aspergillus real-time PCR assays have been described in several reports, but no sources of fungal DNA contamination could be clearly identified. We report a false-positive case for both galactomannan (GM) antigenemia and Aspergillus PCR due to nutritional supplement intake in a bone marrow transplant recipient with digestive graft-versus-host disease. Our case report also suggests that fungal DNA can pass into the serum from the intestinal tract in the same way as fungal GM. Clinicians should be aware of this possibility, so that the administration of costly, unnecessary antifungal treatments with potential adverse side-effects can be avoided.

Indoor mold concentration in Eastern France

Our prospective case-control study of 118 dwellings in Eastern France examined fungal contamination in unhealthy dwellings (n = 32) (homes with visible mold contamination and adverse health outcomes reported by the occupants), dwellings occupied by allergic patients (with medical diagnostic and positive prick-tests for molds) (n = 27) and matched control dwellings (n = 59). Unhealthy dwellings present higher airborne concentrations of Aspergillus, Penicillium, and Cladosporium than control dwellings, irrespective of the room sampled. Bedroom walls were more highly contaminated by molds than others. Dwellings occupied by allergic patients differed significantly for airborne concentrations of Penicillium only, but not for wall surface contamination, whereas bathroom walls were more highly contaminated than other rooms. Molecular identification of 12 Penicillium species showed Penicillium chrysogenum and Penicillium olsonii to be the two main species. From the total average of molds, by impaction method, useful thresholds can be given: below 170 CFU/m(3), between 170 and 560 CFU/m(3), 560 and 1000 CFU/m(3) and above 1000 CFU/m(3), respectively for dwellings with low, moderate, high, and very high concentrations. The latter would be considered a potential health hazard.

PRACTICAL IMPLICATIONS

A single measure of airborne concentrations of molds by impaction allows to establish useful thresholds by social services to estimate in a objective way the housing moldiness. Excluding the summer period, reproducibility of this kind of measure on 3 months, in the fixed limits, is 94.3%. The differences in terms of biodiversity of the unhealthy housing and those accommodating allergic patients imply a specific approach to decrease fungi airborne concentrations. The biodiversity of Penicillium raises the problem of the use of the single extract of Penicillium chrysogenum for skin-tests. The extent of the contaminated surfaces must be measured to assess the potential risk linked to spore contamination. Indeed, surface sampling mostly allows qualitative assessment of the environment.

Personalized management of patients with inoperable alveolar echinococcosis undergoing treatment with albendazole: usefulness of positron-emission-tomography combined with serological and computed tomography follow-up

The present study aimed to identify a sub-group of inoperable alveolar echinococcosis (AE) patients undergoing long-term treatment with benzimidazole (BZM) who presented with an evolution suggestive of a parasitocidal effect. An evolution compatible with parasite death was observed in five patients.

Indoor fungal contamination of moisture-damaged and allergic patient housing analysed using real-time PCR

AIMS

The aim of our study was to compare, using real-time (Rt) PCR, quantitative levels of five fungal species in three kinds of dwellings.

METHODS AND RESULTS

Three groups of homes were recruited: moisture-damaged homes (MDH, n = 30), allergic patient homes (APH, n = 25) and paired control homes (CH, n = 55). Five moulds with allergenic compounds or mycotoxin production characteristics (Cladosporium sphaerospermum, Penicillium chrysogenum, Aspergillus versicolor, Alternaria alternata and Stachybotrys chartarum) were quantified using Rt-PCR. Cycle threshold results were expressed in spore equivalent per volume or surface unit using a direct calculation based on a spore standard curve. MDH presented significantly higher amounts of DNA from C. sphaerospermum in both air and surface samples than CH (P < 0.001). APH presented slightly elevated amounts of DNA from A. versicolor in both air and surface samples, compared to CH (P < 0.05).

CONCLUSION

Rt-PCR quantification of targeted fungal species is a rapid, reliable tool that could be included in a global indoor mould evaluation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Quantification of C. sphaerospermum using Rt-PCR can help to better target social service intervention in MDH. Quantification of A. versicolor DNA could be informative for characterization of APH.

[Alveolar echinococcosis: how to confirm the diagnosis?]

Ultrasonography is the first-step exam for the diagnosis of alveolar echinococcosis. Liver involvement commonly appears as an ill-defined infiltration of the liver parenchyma. Lesions are heterogeneous and in most cases hyperechoic, related to fibro-parasitic tissue associated to scattered calcifications. Hypoechoic foci can also be observed, related to necrosis. In 25 % of the cases, ultrasonography discovers atypical aspects that must be known by radiologists working in endemic region for alveolar echinococcosis. Specific serological tests, particularly ELISA and western blot, usually confirm the diagnosis. Therefore, per-cutaneous punction is exceptionally needed to assess the diagnosis. Other imaging techniques are very useful to complete the diagnosis step and to specify vascular and biliary extension, a crucial information for the therapeutic choice. Computed tomography may show small additional parasitic foci, non visualized by ultrasonography. It allows an accurate examination of the lesions particularly in case of very calcified images that could have made ultrasonographic analysis more difficult. Magnetic resonance imaging may be useful for diagnosis showing on T2 weighted images, in cases of fertile lesions, numerous clustered small cysts. Moreover, it is an excellent technique to analyse vascular involvement, particularly for vena cava and hepatic veins, and to diagnose involvement of adjacent organs. Coupled to cholangio-MR, it allows a precise examination of the biliary tree invasion, particularly in the hilum area.

Multiple-locus variable-number tandem-repeat analysis for rapid typing of Candida glabrata

A multiple-locus variable-number tandem-repeat analysis (MLVA) using six microsatellite markers was assessed in 127 Candida glabrata isolates. Thirty-seven different genotypes, stable both in vitro and in vivo, were observed. The highest discriminatory power (D = 0.902) was reached by using only four markers. MLVA seems to be relevant for C. glabrata typing.

Use of real-time PCR to process the first galactomannan-positive serum sample in diagnosing invasive aspergillosis

Positive galactomannan (GM) anti-genemias are included as a microbiological item in the diagnosis of probable or possible invasive aspergillosis (IA). Because false-positive GM results frequently occur, at least two positive results on two different samples are required. Waiting for clinical specimens can delay the initiation of treatment. As an alternative, we wondered whether detection of circulating Aspergillus DNA on the first positive GM serum sample could aid in diagnosing IA. Therefore, we retrospectively screened the first GM-positive serum samples from 29 patients from our hematology unit for Aspergillus DNA using real-time PCR. We compared the real-time PCR results with the final classification of proven, probable, and possible IA according to consensual criteria. No clear correlation between PCR results and the classification with the medical files could be shown. However, a positive PCR result was associated with a poor prognosis (Fisher's test; P=0.01). Our preliminary data suggest that a positive PCR result could indicate a more advanced stage of the disease. Therefore, concomitant positive PCR and GM results may justify the initiation of antifungal therapy in neutropenic patients. In contrast, a negative PCR on the first positive GM sample may argue for postponing costly antifungal administration until additional arguments for the diagnosis of IA are presented.

Assessment of preemptive treatment to prevent severe candidiasis in critically ill surgical patients(*)

OBJECTIVE

To assess the efficacy of a preemptive antifungal therapy in preventing proven candidiasis in critically ill surgical patients.

DESIGN

Before/after intervention study, with 2-yr prospective and 2-yr historical control cohorts.

SETTING

Surgical intensive care unit (SICU) in a university-affiliated hospital.

PATIENTS

Nine hundred and thirty-three patients, 478 in the prospective group and 455 in the control group, with SICU stay > or =5 days.

INTERVENTIONS

During the prospective period, systematic mycological screening was performed on all patients admitted to the SICU, immediately at admittance and then weekly until discharge. A corrected colonization index was used to assess intensity of Candida mucosal colonization. Patients with corrected colonization index > or =0.4 received early preemptive antifungal therapy (fluconazole intravenously: loading dose 800 mg, then 400 mg/day for 2 wks).

MEASUREMENTS AND MAIN RESULTS

End points of this study were the frequency of proven candidiasis, especially SICU-acquired candidiasis. During the retrospective period, 32 patients of 455 (7%) presented with proven candidiasis: 22 (4.8%) were imported and 10 (2.2%) were SICU-acquired cases. During the prospective period, 96 patients with corrected colonization index > or =0.4 of 478 received preemptive antifungal treatment and only 18 cases (3.8%) of proven candidiasis were diagnosed; all were imported infections. Candida infections occurred more frequently in the control cohort (7% vs. 3.8%; p = .03). Incidence of SICU-acquired proven candidiasis significantly decreased from 2.2% to 0% (p < .001, Fisher test). Incidence of proven imported candidiasis remained unchanged (4.8% vs. 3.8%; p = .42). No emergence of azole-resistant Candida species (especially Candida glabrata, Candida krusei) was noted during the prospective period.

CONCLUSIONS

Targeted preemptive strategy may efficiently prevent acquisition of proven candidiasis in SICU patients. Further studies are being performed to assess cost-effectiveness of this strategy and its impact on selection of azole-resistant Candida strains on a long-term basis.

Evaluation of internal transcribed spacer region of ribosomal DNA sequence analysis for molecular characterization of Candida albicans and Candida dubliniensis isolates from HIV-infected patients

Molecular typing systems have been needed to study Candida colonization in HIV-infected patients, particularly for investigating virulence and fluconazole resistance. Three methods--electrophoretic karyotyping (EK), detection of restriction fragment length polymorphisms (RFLP) and randomly amplified polymorphic DNA analysis (RAPD)--have been most frequently used. In this study, comparative sequence analysis of the internal transcribed spacer (ITS) region of rDNA was evaluated for delineation of Candida isolates from 14 HIV-infected patients. EK, ITS sequence analysis, RFLP and RAPD resulted in 11, 10, 9 and 8 DNA genotypes, respectively, from 39 Candida albicans isolates. The 10 genotypes observed using ITS sequence analysis were defined by six variation sites in the sequence. Molecular typing of sequential oral isolates showed the persistence of the same genotype of C. albicans in nine patients, and genotype variation in one patient. EK and RAPD showed that another patient was co-infected by two distinct genotypes and ITS analysis identified one of the two genotypes as Candida dubliniensis. Comparative ITS sequence analysis is a quick and reproducible method that provides clear and objective results, and it also identifies C. dubliniensis. The discriminatory power of this new typing approach could be improved by concomitant analysis of other DNA polymorphic sequences.