Disseminated Penicillium marneffei infection in an HIV-positive female from Thailand in Germany

Diagnostic performance of immunohistochemistry for the aspergillosis and mucormycosis

OBJECTIVE

To investigate the accuracy of immunohistochemistry (IHC) tests for distinguishing between mucormycosis and aspergillosis and compare the clinical characteristics of mucormycosis patients according to galactomannan (GM) results.

METHODS

We evaluated diagnostic performance of IHC test with tissue sections of patients with culture-proven invasive fungal infection. In addition, we conducted PCR assay with tissue sections of mucormycosis patients with positive GM results to evaluate the possibility of co-infection.

RESULTS

In culture-proven mucormycosis (n = 13) and aspergillosis (n = 20), the sensitivity and specificity of IHC test were both 100% for mucormycosis and 85% and 100%, respectively, for aspergillosis. Among the 53 patients who met the modified criteria for proven mucormycosis and had GM assay results, 24 (45%) were positive. Compared with those with negative GM results (n = 29), mucormycosis patients with positive GM results had significantly higher incidence of gastrointestinal tract infections (6/24 [25%] vs 0/29 [0%], P = .006) and were more likely to be histomorphologically diagnosed as aspergillosis (7/24 [29%] vs 2/29 [7%], P = .06). PCR assay amplified both Aspergillus- and Mucorales-specific DNA in 6 of these 24 cases.

CONCLUSIONS

Immunohistochemistry tests seem useful for compensating for the limitations of histomorphologic diagnosis in distinguishing between mucormycosis and aspergillosis. Some proven mucormycosis patients with positive GM results had histopathology consistent with aspergillosis and gastrointestinal mucormycosis. In addition, about one quarter of these patients revealed the evidence of co-infection with aspergillosis by PCR assay.

Galactomannan detection in broncho-alveolar lavage fluid for invasive aspergillosis in immunocompromised patients

BACKGROUND

Invasive aspergillosis (IA) is a life-threatening opportunistic mycosis that occurs in some people with a compromised immune system. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) rapidly gained widespread acceptance as part of the diagnostic work-up of a patient suspected of IA. Due to its non-invasive nature, it can be used as a routine screening test. The ELISA can also be performed on bronchoalveolar lavage (BAL), allowing sampling of the immediate vicinity of the infection. The invasive nature of acquiring BAL, however, changes the role of the galactomannan test significantly, for example by precluding its use as a routine screening test.

OBJECTIVES

To assess the diagnostic accuracy of galactomannan detection in BAL for the diagnosis of IA in people who are immunocompromised, at different cut-off values for test positivity, in accordance with the Cochrane Diagnostic Test Accuracy Handbook.

SEARCH METHODS

We searched three bibliographic databases including MEDLINE on 9 September 2016 for aspergillosis and galactomannan as text words and subject headings where appropriate. We checked reference lists of included studies for additional studies.

SELECTION CRITERIA

We included cohort studies that examined the accuracy of BAL galactomannan for the diagnosis of IA in immunocompromised patients if they used the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) classification as reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors assessed study quality and extracted data. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used for quality assessment.

MAIN RESULTS

We included 17 studies in our review. All studies except one had a high risk of bias in two or more domains. The diagnostic performance of an optical density index (ODI) of 0.5 as cut-off value was reported in 12 studies (with 1123 patients). The estimated sensitivity was 0.88 (95% confidence interval (CI) 0.75 to 1.00) and specificity 0.81 (95% CI 0.71 to 0.91). The performance of an ODI of 1.0 as cut-off value could be determined in 11 studies (with 648 patients). The sensitivity was 0.78 (95% CI 0.61 to 0.95) and specificity 0.93 (95% CI 0.87 to 0.98). At a cut-off ODI of 1.5 or higher, the heterogeneity in specificity decreased significantly and was invariably >90%.

AUTHORS' CONCLUSIONS

The optimal cut-off value depends on the local incidence and clinical pathway. At a prevalence of 12% a hypothetical population of 1000 patients will consist of 120 patients with IA. At a cut-off value of 0.5 14 patients with IA will be missed and there will be 167 patients incorrectly diagnosed with IA. If we use the test at a cut-off value of 1.0, we will miss 26 patients with IA. And there will be 62 patients incorrectly diagnosed with invasive aspergillosis. The populations and results were very heterogeneous. Therefore, interpretation and extrapolation of these results has to be performed with caution. A test result of 1.5 ODI or higher appears a strong indicator of IA.

Emerging fungal infections in solid organ transplant recipients: Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines review the epidemiology, diagnosis, and management of emerging fungi after organ transplantation. Infections due to numerous generally innocuous fungi are increasingly recognized in solid organ transplant (SOT) recipients, comprising about 7%-10% of fungal infections in this setting. Such infections are collectively referred to as emerging fungal infections and include Mucormycetes, Fusarium, Scedosporium, and dematiaceous fungi among others. The causative organisms are diverse in their pathophysiology, uncommon in the clinical setting, have evolving nomenclature, and are often resistant to multiple commonly used antifungal agents. In recent years significant advances have been made in understanding of the epidemiology of these emerging fungal infections, with improved diagnosis and expanded treatment options. Still, treatment guidelines are generally informed by and limited to experience from cohorts of patients with hematological malignancies and/or solid and stem cell transplants. While multicenter randomized controlled trials are not feasible for these uncommon infections in SOT recipients, collaborative prospective studies can be valuable in providing information on the epidemiology, clinical manifestations, treatment strategies, and outcomes associated with the more commonly encountered infections.

The performance of galactomannan in combination with 1,3-β-D-glucan or aspergillus-lateral flow device for the diagnosis of invasive aspergillosis: Evidences from 13 studies

Galactomannan (GM), 1,3-β-D-glucan (BDG) and aspergillus-lateral flow device (LFD) are recognized as diagnostic tools for invasive aspergillosis (IA). The combined performance of these assays, however, is inconsistent in various studies. We undertook a meta-analysis of 13 studies involving 1513 patients to evaluate the utility of GM in combination with BDG or LFD for diagnosing IA. The pooled SEN, SPE, PLR, NLR and diagnostic odds ratio (DOR) were calculated and constructed to summarize the overall combined performance. Combining both positive results of GM and BDG assays leaded to the pooled SEN 0.49 (95%CI 0.27-0.72), SPE 0.98 (95%CI 0.94-1.00), PLR 31.68 (95%CI 5.36-187.37), NLR 0.52 (95%CI 0.32-0.84) and DOR 61.23 (95%CI 6.96-538.90). Comparing with GM and BDG assays, both positive results of GM and LFD leaded to high SEN, similar SPE, low PLR and NLR. At least one positive result of GM or LFD conferred great SEN 0.93 and low NLR 0.08. Both positive results of GM and BDG or LFD assay were in favor of confirming the existence of IA. And both negative results of GM and LFD were beneficial to rule out IA. Further studies with sufficient sample size should focus on the diagnostic performance and cost-effectiveness of these combined tests in clinical setting.

Recovery from Talaromyces marneffei involving the kidney in a renal transplant recipient: A case report and literature review

Talaromyces marneffei is an emerging opportunistic infection among immunocompromised patients. We observe the first native case of disseminated T. marneffei involving the kidney in a renal transplant recipient in mainland China. We describe the comprehensive clinical course, and ultrasound imaging of renal transplant biopsy, pathologic images, and electron microscopy observation of the biopsy specimen, highlighting the relevance of biopsy findings and the blood culture. We also focus on the treatment and good outcome of the patient. Then we review the literature and show the additional 10 reported cases of T. marneffei in renal transplant recipients. In addition, we discuss the new methods of rapid diagnosis of T. marneffei. In brief, timely diagnosis and proper treatment of T. marneffei infection is important in renal transplant recipients.

A Clinical Study of Acquired Immunodeficiency Syndrome Associated Penicillium Marneffei Infection from a Non-Endemic Area in China

Objective

To investigate the clinical characteristics, diagnosis, treatment and prognosis of penicilliosis among the patients with acquired immunodeficiency syndrome (AIDS) in non-endemic areas of China, and then to discuss its incubation period and the diagnostic performance of serum galactomannan test for penicilliosis.

Methods

Medical records and travel histories of penicilliosis patients in Zhongnan hospital from January 2006 to December 2013, and the interval from when the patients left the endemic area to the onset of the disease was analyzed. Serum galactomannan levels of penicilliosis patients and AIDS patients with fever were measured by the Platelia Aspergillus Enzyme Immunoassay Kit.

Results

A total of 47 AIDS-associated penicilliosis were confirmed by fungal culture, which accounted for 4.8% of 981 AIDS-related admissions. The sensitivity and specificity of serum galactomannan test for penicilliosis were 95.8% (23/24) and 90.9% (30/33), respectively, (cutoff index = 1.0). Two independent predictors for early mortality (death within 12 weeks) of the patients (21.3%, 10/47) were a delayed diagnosis and no treatment with antifungal therapy. Among 14 patients who became ill after leaving endemic areas, ten patients presented with the onset symptoms within 12 months (from 11 days to 360 days). We found a patient living with asymptomatic P. marneffei fungemia who had not received any antifungal therapy until 18 months’ follow up.

Conclusions

The co-infection of P. marneffei and HIV was not uncommon in the non-endemic areas of penicilliosis in China. There exists a latent form of infection for P. marneffei. The incubation period of penicilliosis may be quite different from one patient to another. In AIDS patients, the serum galactomannan test has utility for the diagnosis of penicilliosis. When patients with penicilliosis/AIDS were diagnosed early and treated with standardized antifungal therapy and combined antiretroviral therapy, their prognosis improved.

Non-cultural methods for the diagnosis of invasive fungal disease

Invasive fungal diseases carry a high mortality risk which can be reduced by early treatment. Diagnosing invasive fungal diseases is challenging, because invasive methods for obtaining histological samples are frequently not feasible in thrombocytopenic immunocompromised patients, while fungal cultures have low sensitivity and a long turn-around time. Non-cultural methods are fundamental for a rapid diagnosis of invasive fungal diseases and they include assays based on the detection of fungal antigens (galactomannan, Aspergillus-lateral flow device, [1,3]-β-D-glucan, mannan), antibodies, such as anti-mannan, and molecular tests. With the exception of some molecular methods for rare fungi, the non-cultural assays are usually applied to the diagnosis of invasive aspergillosis, invasive candidiasis and pneumocystosis. The performance of a single test or a combination of tests will be discussed, with particular focus on choosing the most appropriate marker(s) for every specific patient population. Reasons for potential false-positive or false-negative results will be discussed.

Utility of bronchoalveolar lavage fluid galactomannan alone or in combination with PCR for the diagnosis of invasive aspergillosis in adult hematology patients: a systematic review and meta-analysis

BACKGROUND

The clinical utility of bronchoalveolar lavage (BAL) fluid galactomannan (GM) for the early diagnosis of invasive aspergillosis (IA) varies widely across studies mainly due to heterogeneity of the studied populations.

METHODS

We conducted a systematic review and meta-analysis of 16 studies involving 783 adults with hematological malignancies to derive summary estimates of the overall accuracy of BAL-GM for diagnosing IA.

FINDINGS

Summary estimates of BAL-GM using an optical density (OD) index cutoff value of 1.5 for proven and probable IA were: sensitivity 0.92 (95% CI = 0.48-0.99), specificity 0.98 (95% CI = 0.78-1.00), positive likelihood ratio 53.7 (95% CI = 3.7-771.8), and negative likelihood ratio 0.08 (95% CI = 0.01-0.83). Comparing serum GM and Aspergillus PCR testing on BAL fluid, BAL-GM conferred greater sensitivity, but lower specificity than the serum GM test, and similar specificity as the PCR assay. The use of BAL-GM with serum GM or BAL-PCR tests increased the sensitivity moderately when a positive result was defined by either assay.

INTERPRETATION

GM quantification in BAL fluid at an OD index cutoff value of 1.5 has excellent sensitivity and specificity to assist clinical decision-making in confirming or excluding a diagnosis of IA when results are interpreted with clinical findings. Additional research investigating the effects of antifungal agents, optimal timing and processing of BAL sampling are needed to improve the diagnostic accuracy of BAL-GM testing.

Aspergillus endocarditis: a review of the literature

We present a case of cardiac device-related Aspergillus endocarditis in a patient with a pacemaker and an allogeneic bone marrow transplant to segue into a review of the Aspergillus endocarditis literature. Aspergillus endocarditis should be suspected in patients with underlying immunosuppression, negative cultures, and a vegetation on echocardiography. Diagnosis ultimately requires confirmation by tissue histology and culture. The optimal treatment approach often requires aggressive surgical debridement in conjunction with prolonged antifungal therapy.

Unusual microbial organisms seen in two cervical smears

Very infrequently, unusual microbial organisms are encountered in routine cervical Pap tests. We herein report two such cases in two asymptomatic women. Case 1. A Pap smear of a 16-year-old-female showed rare glandular cells with cytologic features consistent with Cytomegalovirus infection. Case 2. A Pap smear of a 36-year-old female exhibited rare fungal organisms characterized by thin septate hyphae branching into secondary branches (metulae) which carried multiple flask-shaped philiades most consistent with Penicillium species that were "most likely representing contamination." We discuss the cytomorphological features and the differential diagnosis and provide a brief review of the literature on these topics.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

Transmission of tropical and geographically restricted infections during solid-organ transplantation

In recent years, the increasing number of donors from different regions of the world is providing a new challenge for the management and selection of suitable donors. This is a worldwide problem in most countries with transplantation programs, especially due to the increase in immigration and international travel. This paper elaborates recommendations regarding the selection criteria for donors from foreign countries who could potentially transmit tropical or geographically restricted infections to solid-organ transplant recipients. For this purpose, an extensive review of the medical literature focusing on viral, fungal, and parasitic infections that could be transmitted during transplantation from donors who have lived or traveled in countries where these infections are endemic has been performed, with special emphasis on tropical and imported infections. The review also includes cases described in the literature as well as risks of transmission during transplantation, microbiological tests available, and recommendations for each infection. A table listing different infectious agents with their geographic distributions and specific recommendations is included.

Well-characterized monoclonal antibodies against cell wall antigen of Aspergillus species improve immunoassay specificity and sensitivity

The diagnosis of invasive aspergillosis (IA) based on the detection of Aspergillus galactomannan (GM) is complicated by the presence of cross-reactive GM epitopes in patient specimens. We have developed a novel and specific Aspergillus antigen-capture enzyme-linked immunosorbent assay (ELISA) by the selection of two well-characterized monoclonal antibodies from 17 candidate antibodies. The epitopes recognized by the monoclonal antibodies were present on the cell walls of the hyphae and the conidia of Aspergillus species, which were circulating or excreted as immunodominant antigens during the acute phase of IA established in the animal models. The detection of experimental Aspergillus-mediated antigenemia was suitably sensitive, and the sensitivity was comparable to that of a commercial GM detection ELISA kit (the Platelia Aspergillus assay). Moreover, the specificity of this assay was 100% when it was used to test 382 serum specimens and 120 urine specimens from healthy individuals. Cross-reactivity with other common opportunistic fungi, such as Penicillium and Candida species, and with purified GM protein derived from Aspergillus was not evident. Therefore, the chemical nature of the epitopes captured in this assay is most likely not associated with the GM structure, indicating that this newly developed Aspergillus antigen-capture ELISA is a promising tool for the diagnosis of IA without the risk of the false-positive results that are problematic with current GM antigen assays.

Detection of circulating galactomannan in serum samples for diagnosis of Penicillium marneffei infection and cryptococcosis among patients infected with human immunodeficiency virus

Galactomannan (GM) is a heteropolysaccharide in the cell walls of most Aspergillus and Penicillium species. Cross-reactivity of Cryptococcus neoformans galactoxylomannan in an Aspergillus GM test has also been reported. In this study, we used a Platelia Aspergillus enzyme immunoassay kit (Bio-Rad) to test serum samples obtained from 48 human immunodeficiency virus (HIV)-infected patients (15 with penicilliosis [7 with fungemia alone, 4 with cavitary lung lesions alone, 3 with both fungemia and cavitary lung lesions, and 1 with disseminated disease], 22 with cryptococcosis [11 with fungemia alone, 5 with cavitary lung lesions, 3 with both, and 3 with meningitis alone], and 11 without any invasive fungal infection [control]) for GM levels. None of the patients had aspergillosis or concurrent use of piperacillin-tazobactam or amoxicillin-clavulanate. The median time between diagnosis of fungal infection and collection of serum samples was 0 days for penicilliosis and 1.5 days for cryptococcosis. Of patients with penicilliosis, cryptococcosis, and controls, 73.3%, 13.6%, and 9%, respectively, had GM optical density (OD) indices of >0.5 (P = 0.0001). GM OD indices were higher for penicilliosis (median OD index, 4.419; range, 0.158 to >20) than for cryptococcosis (median, 0.247; range, 0.112 to 3.849) cases (P < 0.001). Patients with fungemic penicilliosis had higher OD indices (median, 10.628; range, 0.401 to >20) than patients with nonfungemic penicilliosis (median, 0.378; range, 0.158 to 4.419) and patients with cryptococcemia (median, 0.231; range, 0.112 to 1.168) (P < 0.001). Of the 15 patients with cavitary lung lesions, those with penicilliosis had higher antigen levels (median OD index, 1.641; range, 0.247 to >20) than those with cryptococcosis (median, 0.227; range, 0.112 to 3.849) (P = 0.011). This study showed that the GM OD index was significantly elevated for HIV patients with penicilliosis. The use of the GM antigen assay may facilitate earlier diagnosis of Penicillium marneffei infection for HIV-infected patients in areas of endemicity.

Update on the contribution of galactomannan for the diagnosis of invasive aspergillosis

The diagnosis of invasive fungal infections (IFI) remains a challenge, particularly for diseases caused by filamentous fungi such as Aspergillus species. Unfortunately, many patients affected by these conditions are not identified before autopsy. Therefore, there is a need for new diagnostic methods for IFI. Galactomannan is a soluble antigen released during hyphal growth in tissues. A commercially available sandwich ELISA assay that detects galactomannan has been used in Europe for many years and is now approved for use in the USA. The test has an excellent negative predictive value in the detection of invasive aspergillosis (IA) in high-risk patients. In addition, it is more sensitive than culture and allows IA to be diagnosed before clinical manifestations occur. However, false-negative and false-positive results in certain populations are the main limitations to its use. The purpose of this review is to summarize the current knowledge about galactomannan testing in patients at risk for IA.

Aspergillus galactomannan enzyme-linked immunosorbent assay cross-reactivity caused by invasive Geotrichum capitatum

We report three cases of invasive Geotrichum capitatum infection in patients with acute leukemia for which an enzyme-linked immunosorbent assay (ELISA) for Aspergillus galactomannan was positive, with no evidence of aspergillosis. Supernatants obtained from suspensions of 17 G. capitatum strains gave positive reactions with the Aspergillus galactomannan ELISA. These clinical and laboratory data seem to suggest that G. capitatum produces a soluble antigen that is cross-reactive with Aspergillus galactomannan.

Disseminated Penicillium marneffei infection in an HIV-positive Italian patient and a review of cases reported outside endemic regions

We describe a case of disseminated Penicillium marneffei in a human immunodeficiency virus (HIV)-positive Italian man who stayed for 4 years in Chiang Ray province, northern Thailand. A review of the literature shows that penicilliosis, although unusual, may represent an emerging opportunistic infection among HIV-positive people traveling to endemic areas.

Penicillium marneffei infection and recent advances in the epidemiology and molecular biology aspects

Penicillium marneffei infection is an important emerging public health problem, especially among patients infected with human immunodeficiency virus in the areas of endemicity in southeast Asia, India, and China. Within these regions, P. marneffei infection is regarded as an AIDS-defining illness, and the severity of the disease depends on the immunological status of the infected individual. Early diagnosis by serologic and molecular assay-based methods have been developed and are proving to be important in diagnosing infection. The occurrence of natural reservoirs and the molecular epidemiology of P. marneffei have been studied; however, the natural history and mode of transmission of the organism remain unclear. Soil exposure, especially during the rainy season, has been suggested to be a critical risk factor. Using a highly discriminatory molecular technique, multilocus microsatellite typing, to characterize this fungus, several isolates from bamboo rats and humans were shown to share identical multilocus genotypes. These data suggest either that transmission of P. marneffei may occur from rodents to humans or that rodents and humans are coinfected from common environmental sources. These putative natural cycles of P. marneffei infection need further investigation. Studies on the fungal genetics of P. marneffei have been focused on the characterization of genetic determinants that may play important roles in asexual development, mycelial-to-yeast phase transition, and the expression of antigenic determinants. Molecular studies have identified several genes involved in germination, hyphal development, conidiogenesis, and yeast cell polarity. A number of functionally important genes, such as the malate synthase- and catalase-peroxidase protein-encoding genes, have been identified as being upregulated in the yeast phase. Future investigations pertaining to the roles of these genes in host-fungus interactions may provide the key knowledge to understanding the pathogenicity of P. marneffei.

Development and evaluation of a one-tube seminested PCR assay for the detection and identification of Penicillium marneffei

A one-tube seminested polymerase chain reaction (PCR) assay was developed to detect and identify Penicillium marneffei DNA coding for 18S rRNA both from purified DNA and from clinical samples. DNA from 120 strains of organisms and 19 blood samples from AIDS patients was amplified with F3, CPL1 and PM primers. Under optimized conditions, these primers detected 100% specifically amplified products of 251 and 331 bp from all P. marneffei DNA preparations (47 strains) and from two blood samples of AIDS patients suspected to suffer from penicilliosis marneffei. The assay was sensitive to detect as little as 10 pg purified DNA, which is equivalent to 250 cells. This PCR assay might be useful as an alternative test, if a rapid diagnosis of penicilliosis marneffei is needed.