Rapid detection of fungal pathogens in bronchoalveolar lavage samples using panfungal PCR combined with high resolution melting analysis.

Despite advances in the treatment of invasive fungal diseases (IFD), mortality rates remain high. Moreover, due to the expanding spectrum of causative agents, fast and accurate pathogen identification is necessary. We designed a panfungal polymerase chain reaction (PCR), which targets the highly variable ITS2 region of rDNA genes and uses high resolution melting analysis (HRM) for subsequent species identification. The sensitivity and specificity of this method was tested on a broad spectrum of the most clinically important fungal pathogens including Aspergillus spp., Candida spp. and mucormycetes. Despite the fact that fluid from bronchoalveolar lavage (BAL) is one of the most frequently tested materials there is a lack of literature sources aimed at panfungal PCR as an IFD diagnostic tool from BAL samples. The applicability of this method in routine practice was evaluated on 104 BAL samples from immunocompromised patients. Due to high ITS region variability, we obtained divergent melting peaks for different fungal species. Thirteen out of 18 patients with proven or probable IFD were positive. Therefore, the sensitivity, specificity, positive predictive value and negative predictive value of our method were 67%, 100%, 100%, and 94%, respectively. In our assay, fungal pathogens identification is based on HRM, therefore omitting the expensive and time consuming sequencing step. With the high specificity, positive and negative predictive values, short time needed to obtain a result, and low price, the presented assay is intended to be used as a quick screening method for patients at risk of IFD.

Disseminated fusariosis by Fusarium proliferatum in a patient with aplastic anaemia receiving primary posaconazole prophylaxis - case report and review of the literature.

Disseminated fusariosis is a life-threatening, invasive, opportunistic infection in immunocompromised patients, especially those with haematological malignancies. The prognosis is poor because these fungi are resistant to many of the available antifungal agents. We present a case of disseminated fusariosis caused by Fusarium proliferatum in a patient with severe aplastic anaemia complicated by a secondary infection of Aspergillus flavus, with a fatal outcome. We also review the documented Fusarium infections in immunocompromised hosts.

[Treatment of 14 cases of Castlemans disease: the experience of one centre and an overview of literature]. / Lécba 14 prípadu Castlemanovy nemoci: zkusenosti jednoho centra a prehled literatury.

Castlemans disease is the term for reactive lymphocytary and plasmocytary proliferation which occurs in the unicentric (localized) form, usually without systemic symptoms, or in the generalized/multicentric form, typically with systemic symptoms (www.vzacne-diagnozy.cz). Over the past 25 years we diagnosed, treated and followed 14 histologically proven cases of Castlemans diseases. Seven patients had the localised form of the disease. In 5 of 7 cases the pathological lesion was located intrathoracically or intraabdominally and in only 2 cases it was on the surface of the body. No clinical symptoms were present in any of the patients with the unicentric form of the disease and surgical treatment led to the total removing of the disease in all of them. As opposed to that, all 7 patients with the multicentric form of Castlemans disease experienced febrile or subfebrile temperatures. Three of the 7 patients complained of severe troubling night sweats. Clinical expressions of vasculitis which was the cause of stroke, were present in 1 of 7 patients. Osteosclerotic changes on the skeleton were detected in 1 patient, who also suffered from fluid retention likely associated with this disease. Polyclonal propagation of immunoglobulins, predominantly immunoglobulin IgG type, was present in 5 of 7 patients with the multicentric form. In one case there was one complete molecule of monoclonal imunoglobuline present and in one case loose light chains κ were increased More than 1 sampling of material for histological examination of enlarged lymph nodes were needed in 6 of 7 patients for diagnosing the multicentric form of the disease. It has turned out beneficial with respect to diagnosing the disease to carry out surgical removal and histological examination of the nodes which accumulated the most fluorodeoxyglucose within PET-CT examination. The text describes experience of the treatment. In recent years the basis for the treatment has been the monoclonal antibody antiCD20 rituximab, or thalidomide and lenalidomide, or possibly their combination. The new medicine for these patients is interleukin-6 antibody called siltuximab (Sylvant), of which we have no own experience so far. Five of our seven patients with the multicentric form received treatment, 1 patient refused treatment and in one patient the signs of the disease activity are not expressed to such extent that would require treatment. The therapy containing rituximab reached complete remission in 2 patients and the therapy containing thalidomide and lenalidomide achieved the complete remission of the disease in 3 patients. In one of the above described cases the disease did not respond to the initial treatment with rituximab and remission was reached by thalidomide and lenalidomide and in one case the disease did not respond to the initial treatment with thalidomide and complete remission was reached with rituximab. Following the treatment, no patient with the multicentric form of Castlemans disease has had a relapse until now.

Ofatumumab added to dexamethasone in patients with relapsed or refractory chronic lymphocytic leukemia: Results from a phase II study.

The treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) remains a challenging clinical issue. An important treatment option is the use of high-dose corticosteroids. The purpose of this clinical trial was to determine the efficacy and toxicity of an ofatumumab-dexamethasone (O-Dex) combination in relapsed or refractory CLL. The trial was an open-label, multicenter, nonrandomized, Phase II study. The O-Dex regimen consisted of intravenous ofatumumab (Cycle 1: 300 mg on day 1, 2,000 mg on days 8, 15, and 22; Cycles 2-6: 1,000 mg on days 1, 8, 15, and 22) and oral dexamethasone (40 mg on days 1-4 and 15-18; Cycles 1-6). The O-Dex regimen was given until best response, or a maximum of six cycles. Thirty-three patients (pts) were recruited. Twenty-four (73%) pts completed at least three cycles of therapy. The remaining nine pts were prematurely discontinued owing to Grade 3/4 infections (seven pts), disease progression (one pt), or uncontrollable diabetes mellitus (one pt). Overall response rates/complete remissions (ORR/CR) were achieved in 22/5 pts (67/15%). The median progression-free survival (PFS) was 10 months. In pts with p53 defects (n = 8), ORR/CR were achieved in 5/2 pts (63/25%) with a median PFS of 10.5 months. The median overall survival (OS) was 34 months. The Grades 3-5 infectious toxicity in 33% of pts represented the most frequent side effect during the treatment period. In conclusion, the O-Dex regimen shows a relatively high ORR and CR with promising findings for PFS and OS. The study was registered at www.clinicaltrials.gov (NCT01310101).

[PET-CT documented remission of multicentric Castleman disease after treatment with rituximab: case report and review]. / PET-CT dokumentovaná remise multicentrické formy Castlemanovy choroby po lécbe rituximabem Popis prípadu a prehled literatury.

We describe a case of multicentric Castleman disease with generalized lymphadenopathy and splenomegaly, accompanied by typical B symptoms - loss of 15 kg, fever of non-infectious origin, night sweats, symptoms of anemia. Histological examination of the nodes with the highest accumulation of fluorodeoxyglucose, taken from mediastinum by thoracoscopy, revealed plasmocellular type of Castleman disease. Tests for HIV and human herpesvirus 8 (HHV-8) were negative. Three recurrences of herpes zoster indicating an alteration of immunity preceded the dia-gnosis of disease. Treatment was initiated with combination of thalidomide, dexamethasone, and cyclophosphamide. The response after 2 months therapy was not clear and patient doesn't tolerated the therapy well. Therefore, this treatment was terminated and R-CHOP (Mabthera - rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone) was selected as a second-line therapy. Lymphadenopathy and splenomegaly were reduced during the 2 cycles of treatment, however, serious infectious complications accompanied the therapy. Therefore, only use of Mabthera monotherapy 375 mg /m2 was administered in 28-day intervals. This treatment has shown efficacy and tolerability. PET-CT scan has demonstrated disappearance of lymphadenopathy and splenomegaly, in addition, normalized accumulation of fluorodeoxyglucose. Monotherapy with Mabthera has proved to be effective and well tolerated drug in this case. Currently, there are more effective therapeutic alternatives in multicentric Castleman disease: treatment with monotherapy of rituximab or in combination therapy with immunomodulatory drugs (thalidomide or lenalidomide, treatment with anti-IL-6 (siltuximab) or against its receptor (tocilizumab). In the case of ineffectiveness of one treatment option must be tested other alternative. In this case the therapy based on thalidomide wasn't successful, whereas the treatment with Mabthera has achieved disappearance of disease symptoms.

Rapid detection and identification of mucormycetes in bronchoalveolar lavage samples from immunocompromised patients with pulmonary infiltrates by use of high-resolution melt analysis.

Rapid differential diagnostics of pulmonary infiltrates suspected of invasive fungal disease in an immunocompromised host and early initiation of effective antifungal therapy are crucial for patient outcomes. There are no serological tests available to detect mucormycetes; therefore, PCR-based methods are highly suitable. We validated our previously published PCR followed by high-resolution melt analysis (PCR/HRMA) to detect Rhizopus spp., Rhizomucor pusillus, Lichtheimia corymbifera, and Mucor spp. in bronchoalveolar lavage (BAL) samples from immunocompromised patients who were at risk of invasive fungal disease. All PCR/HRMA-positive samples were retested using novel real-time quantitative PCR (RQ PCR) assays specific to the species identified. In total, between January 2009 and December 2012 we analyzed 99 BAL samples from 86 patients with pulmonary abnormalities using PCR/HRMA. Ninety (91%) BAL samples were negative, and 9 (9%) samples were positive. The sensitivity and specificity of PCR/HRMA were 100% and 93%, respectively. By combining the positive results of PCR/HRMA with positive RQ PCR results, the specificity was raised to 98%. PCR/HRMA, due to its high negative predictive value (99%), represents a fast and reliable tool for routine BAL sample screening for the differential diagnosis of pulmonary infiltrates in immunocompromised patients for the four most clinically important mucormycetes.

[Invasive fungal infections in immunocompromised patients with focus on aspergillosis and its causative agents]. / Invazivní mykatické infekce u imunokompromitovaných nemocných se zamerením na aspergilózu a její puvodce.

Invasive fungal diseases (IFD) are a life-threatening infectious complications in immunocompromised patients and are associated with high rate of morbidity and mortality. The most common invasive mycosis in patients who underwent an allogeneic hematopoietic stem cell transplantation is invasive aspergilosis (IA), most frequently caused by the clinically dominant species Aspergillus fumigatus and, rarely, also by Aspergillus flavus, Aspergillus terreus and Aspergillus niger. In recent years, other related Aspergillus species were also reported to cause IFD, phenotypically similar to A. fumigatus and moreover, frequently exhibiting resistance towards various antifungals. For example, it is Aspergillus lentulus, Aspergillus viridinutans, Neosartoya fischeri, etc. Classical microbiological methods such as direct microscopy or culture are usually used for the identification of Aspergillus species. The application of PCR-based molecular techniques and monitoring of secondary metabolites production enable detection and identification of species, which are not distinguishable solely by their morphology. PCR methods are also useful for molecular strain typing of aspergilli and can reveal the genetic diversity of isolates.

[Detection and identification of filamentous fungi causing mycoses using molecular genetic methods]. / Detekce a identifikace puvodcu mykotických infekcí zpusobených vlaknitými houbami pomocí metod molekulární genetiky.

Methods of molecular genetics offer rapid and sensitive detection and identification of fungal pathogens. The currently used methods are based mainly on PCR. With regard to the ubiquitous presence of fungi, it is important to prevent contamination during the whole process, from sampling to laboratory analyses. Molecular genetic methods are not included among the EORTC/MSG criteria used for the diagnosis of invasive fungal diseases since interlaboratory standardization is still missing. Another reason is the use of different target genes for PCR. ITS sequences from rDNA clusters are recommended for DNA barcoding of fungi. The use of DNA sequencing for identification of fungi in clinical samples has certain limitations and interpretation of results could be problematic in some cases. DNA sequences are searched and compared in public databases on the Internet, the best known of them being the GenBank. However, more reliable data for identification of fungi are offered by specialized mycological databases.

[Role of PCR detection and quantification of herpes viruses in bronchoalveolar lavage of immunocompromised patients]. / Význam PCR detekce a kvantifikace herpetických viru v bronchoalveolární lavázi imunokompromitovaných pacientu.

Herpes virus infections represent common complications associated with respiratory tract involvement which may result in pneumonia development in immunocompromised patients. The analysis of bronchoalveolar lavage (BAL) fluid obtained from the lower respiratory tract may contribute to detection of aetiological agents of the disease. The routine use of quantitative molecular methods enables the discrimination between acute infection and viral reactivation with asymptomatic virus shedding. The aim of this review is to evaluate the contribution of BAL viral load monitoring in high-risk patients and to determine the cut-off of viral load leading to progression to herpes virus pneumonia.

Rapid detection and identification of mucormycetes from culture and tissue samples by use of high-resolution melt analysis.

We present a method for rapid and simple detection of clinically relevant mucormycetes of the Mucorales order in cultures and clinical samples. This seminested real-time PCR uses mucormycete-specific primers and is followed by species identification using high-resolution melt (HRM) analysis. The method is highly suitable for routine clinical diagnostics.

Invasive Rhino-Orbito-Cerebral Mucormycosis in Pediatric Patient with Acute Leukemia.

BACKGROUND: Invasive fungal infections are a life-threatening complication of cancer treatments, especially in hemato-oncological patients. Mucormycosis is the third leading cause of invasive fungal infections after Aspergillus and Candida infections. The first clinical symptoms are usually non-specific, which can lead to a late diagnosis and delayed therapy. PURPOSE: The objective of this report is to summarize data in the literature about mucormycosis and to present a case report of a patient with acute lymphoblastic leukemia, who developed this infection at our center. Risk factors for the development of mucormycosis, clinical symptoms, radiology, laboratory results, and outcome were retrospectively evaluated. CASE: We describe a 6-years-old female patient with acute lymphoblastic leukemia. During the induction phase of therapy, the patient developed febrile neutropenia and did not respond to therapy with a combination of antibiotics and supportive treatment. Pansinusitis and orbitocellulitis developed. Examination of the biological material revealed that the etiological agent was a Rhizopus sp. The patient was treated with a combination of antimycotic drugs, but the infection disseminated to the central nervous system. She underwent radical surgical resection of the affected tissue. At this time, she is still under treatment with antimycotic and oncology agents, but is in remission of the main diagnosis and in good clinical condition. CONCLUSION: Mucormycosis is an invasive fungal infection with high morbidity and mortality. Early diagnosis and initiation of effective therapy using a combination of amphotericin B administration and surgery are necessary to obtain a favorable outcome. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

[Detection of invasive aspergillosis by PCR and real-time PCR--benefits and drawbacks]. / Detekce invazivní aspergilózy pomocí PCR a real-time PCR--prednosti a úskalí.

PCR detection of fungal pathogens in clinical samples has been discussed in journals for more than two decades. However, its use for diagnosing invasive aspergillosis is still controversial, despite the fact that molecular methods are routinely used in various fields of modern microbiology. These are e. g. genotyping of bacterial strains resistant to antibiotics, molecular epidemiology or routine detection of viral infections in clinical material. PCR methods have made the diagnostic applications faster, simpler and more accurate. This review deals with issues related to molecular methods for diagnosing invasive fungal infections and the main factors limiting their use in everyday clinical practice.

[Problems of cytomegalovirus diagnostics by real-time polymerase chain reaction.].

AIM OF THE STUDY: The main goal was to explain the discrepancies between two PCR methods used for detection of cytomegalovirus (CMV) in peripheral blood samples of patients of Department of Internal Medicine-Hematooncology, University Hospital, Brno. MATERIALS AND METHODS: In past we used exon 4 of major immediate-early (MIE) gene as the target for quantitative detection of the CMV in clinical samples, but sometimes this method failed to detect the viral load in samples that were positively tested using less sensitive qualitative method targeting another region (exon 2-4) of the same gene. From January 2004 to January 2005 we totally tested samples from 363 patients. 64 patients were at least once CMV positive using quantitative method, but 20 patients were repeatedly false negative.To find the cause of this discrepancy we performed partial sequence analysis of this region (nt positions 2719-2919, GenBank M21295) and glycoprotein B (gB) genotyping. We sequenced samples from 35 patients-15 giving true positive (both in qualitative and quantitative method) and 20 giving false negative (negative in quantitative but positive in qualitative method) results in several consecutive blood samples. RESULTS: The 15 true positive samples were 100% homological, whereas all 20 false negative samples showed high degree of variation from the laboratory strain AD169. These changes are not random and indicate that the two groups of patients were infected by different CMV genotypes. Moreover, sequence alignment showed similarity to laboratory strains Toledo and Towne. No preferential concordance was observed between clinical context, MIE exon 4 sequence and gB groups. CONCLUSIONS: Because of high sequence variability exon 4 of MIE gene can not be used for routine diagnostics. Genetic varibility among the pathogenic strains may seriously affect its proper diagnostics.

Detecting human cytomegalovirus drug resistant mutations and monitoring the emergence of resistant strains using real-time PCR.

BACKGROUND: Antiviral resistance development is a serious complication of human cytomegalovirus virostatic therapy caused by mutations in UL 97 and/or UL54 genes. OBJECTIVES: To determinate the presence of sensitive and resistant strains in patients developing antiviral resistance. STUDY DESIGN: We used three different molecular biological methods for mutation analysis-restriction fragment length polymorphism, sequencing and real-time PCR approach. RESULTS: We describe three allogeneic hematopoietic stem cell transplant patients developing the GCV resistant HCMV strains manifested by virostatic treatment failure. In these patients we identified UL97 mutations L595S, A594V and A594T and monitored the dynamics of coexisted sensitive/resistant strains. We confirmed the presence of mixed HCMV populations and in two patients a phenomenon of sensitive strain repopulation which occurred after 6.5 months and 1 month after removing GCV pressure. CONCLUSIONS: Our results show changes in proportions of sensitive/resistant subpopulations over time but other studies would be required to demonstrate the beneficial impact of their monitoring on clinical outcome.

Galactomannan detection in bronchoalveolar lavage fluid for the diagnosis of invasive aspergillosis in patients with hematological diseases-the role of factors affecting assay performance.

BACKGROUND: We evaluated the performance of a galactomannan (GM) assay in bronchoalveolar lavage (BAL) fluid compared to serum samples for the diagnosis of invasive pulmonary aspergillosis (IPA) in patients with hematological diseases. METHODS: Two hundred and fifty-five bronchoscopies were performed on 230 patients. Bronchial and alveolar samples from BAL fluid as well as serum samples were analyzed in the GM assay. RESULTS: Twenty-eight cases of IPA (11%) were diagnosed. The sensitivity, specificity, positive predictive value, and negative predictive value of the GM assay using a cut-off of 0.5 were 57.1%, 99.3%, 94.1%, and 92.5%, respectively, for the alveolar sample; 44.0%, 99.3%, 91.7%, and 91.4%, respectively, for the bronchial sample; and 60.7%, 100%, 100%, and 92.9%, respectively, for serum. The highest sensitivity (78.6%) with good specificity (98.6%) was obtained with a 'triple detection' of GM in bronchial, alveolar, and serum samples. Neutropenia and antifungal therapy for only 24h increased the sensitivity, while antifungal treatment for ≥ 2 days decreased assay performance. Moreover, a trend towards a higher volume of aspirated fluid in GM-negative BAL (p=0.092) was observed. CONCLUSIONS: In contrast to recently published data, we found only moderate sensitivity, but high specificity and high positive predictive value of the detection of GM in BAL fluid. In addition, neutropenia, antifungal therapy, and BAL standardization affected GM assay performance.

Real-time PCR diagnostics failure caused by nucleotide variability within exon 4 of the human cytomegalovirus major immediate-early gene.

Here we report how variability in the human cytomegalovirus genome sequence may seriously affect the outcome of its molecular diagnosis. A real-time quantitative PCR assay targeting the major immediate-early gene failed to detect the viral load in some, but not all, clinical samples from hematooncological patients. By amplification and sequencing the DNA across the regions targeted by this assay we found a number of nucleotide substitutions which accounted for decreased primer/probe binding. This decreased the sensitivity of the assay up to 1,000-fold.