Susceptibility to fungal infections of nails in patients with primary antibody deficiency

Primary antibody deficiencies are rare diseases, which require early treatment with intravenous immunoglobulins to prevent fatal infections. The cell mediated immunity in patients with those immunodeficiencies remains unimpaired and usually they do not develop fungal infections. The aim of the study was to determine the susceptibility to fungal infections of nails in children with X-linked agammaglobulinaemia (XLA) and common variable immunodeficiency (CVID). Nail plate fragments collected from five patients with XLA and five with CVID were experimentally infected with a Candida albicans and Trichophyton mentagrophytes strains. The same procedures were carried out with the nails from a control group of 10 healthy volunteers. The intensity of the infection was evaluated on the basis of hyphae ingrown into the nail fragments. The main finding of the study was the increased susceptibility of antibody deficient patients to experimental nail infection with C. albicans and T. mentagrophytes.

Drosophila melanogaster antimicrobial defense

The Drosophila melanogaster host defense is complex but remarkably efficient. It is a multifaceted response to a variety of fungal, bacterial, and parasitic invaders. Current knowledge is discussed on recognition of infectious microorganisms and on the activation of intracellular signaling cascades that concur with the expression of numerous immune-responsive genes, among which, to date, the most prominent appear to encode potent antimicrobial peptides.

Quantitation of anti-Pneumocystis jiroveci antibodies in healthy persons and immunocompromised patients

To facilitate studies of the epidemiology of Pneumocystis jiroveci infection in both healthy persons and immunocompromised patients, we developed a quantitative ELISA with recombinant major surface glycoprotein (MSG) fragment MSG-14, a P. jiroveci-specific protein that includes a highly conserved region of the MSG protein family. By immunoblot, all samples reacted with the carboxyl portion of MSG-14; by ELISA, immunocompromised patients with Pneumocystis pneumonia (PCP) who were immunocompromised for reasons other than AIDS had higher antibody levels than did either patients with AIDS with PCP (P=.01) or healthy persons (P=.005). Longitudinal observations of 8 patients with AIDS showed no correlation between time of diagnosis of Pneumocystis infection and change in antibody levels. Eleven percent (4/35) of healthy persons demonstrated a >4-fold change in antibody titers during 1 year of observation. This ELISA assay allows quantitation of anti-P. jiroveci antibodies in human serum samples and should be useful in better understanding the epidemiology of P. jiroveci infection in humans.

Disseminated trichosporonosis in a murine model of chronic granulomatous disease

Over a period of ten months, five mice submitted to our service (the Pathology Section of the Veterinary Resources Program, Office of Research Services at the National Institutes of Health, Bethesda, Md.) were diagnosed with disseminated trichosporonosis. These mice had pyogranulomatous inflammation in multiple organs, including lung, liver, lymph nodes, salivary gland, and skin. Fungal elements in many of the lesions were identified, using special histochemical stains, and Trichosporon beigelii was obtained by use of culture of specimens at affected sites. This saprophytic fungus has caused disseminated disease in immunosuppressed humans. However, despite widespread use of immunosuppressed rodents in research, to the authors' knowledge, this organism had not previously been reported to cause spontaneous disseminated disease in laboratory mice. All affected mice had a genetically engineered defect in p47(phox), a critical component of the nicotinamide dinucleotide phosphate (NADPH) oxidase, the enzyme responsible for generating the phagocyte oxidative burst. These animals are used as a murine model of human chronic granulomatous disease. We discuss the lesions, differential diagnosis, identification of the organism, and the role of NADPH oxidase in protecting against disseminated trichosporonosis.

Adverse human health effects associated with molds in the indoor environment

Molds are common and important allergens. About 5% of individuals are predicted to have some allergic airway symptoms from molds over their lifetime. However, it should be remembered that molds are not dominant allergens and that the outdoor molds, rather than indoor ones, are the most important. For almost all allergic individuals, the reactions will be limited to rhinitis or asthma; sinusitis may occur secondarily due to obstruction. Rarely do sensitized individuals develop uncommon conditions such as ABPA or AFS. To reduce the risk of developing or exacerbating allergies, mold should not be allowed to grow unchecked indoors. When mold colonization is discovered in the home, school, or office, it should be remediated after the source of the moisture that supports its growth is identified and eliminated. Authoritative guidelines for mold remediation are available. Fungi are rarely significant pathogens for humans. Superficial fungal infections of the skin and nails are relatively common in normal individuals, but those infections are readily treated and generally resolve without complication. Fungal infections of deeper tissues are rare and in general are limited to persons with severely impaired immune systems. The leading pathogenic fungi for persons with nonimpaired immune function, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma, may find their way indoors with outdoor air but normally do not grow or propagate indoors. Due to the ubiquity of fungi in the environment, it is not possible to prevent immunecompromised individuals from being exposed to molds and fungi outside the confines of hospital isolation units. Some molds that propagate indoors may under some conditions produce mycotoxins that can adversely affect living cells and organisms by a variety of mechanisms. Adverse effects of molds and mycotoxins have been recognized for centuries following ingestion of contaminated foods. Occupational diseases are also recognized in association with inhalation exposure to fungi, bacteria, and other organic matter, usually in industrial or agricultural settings. Molds growing indoors are believed by some to cause building-related symptoms. Despite a voluminous literature on the subject, the causal association remains weak and unproven, particularly with respect to causation by mycotoxins. One mold in particular, Stachybotrys chartarum, is blamed for a diverse array of maladies when it is found indoors. Despite its well-known ability to produce mycotoxins under appropriate growth conditions, years of intensive study have failed to establish exposure to S. chartarum in home, school, or office environments as a cause of adverse human health effects. Levels of exposure in the indoor environment, dose-response data in animals, and dose-rate considerations suggest that delivery by the inhalation route of a toxic dose of mycotoxins in the indoor environment is highly unlikely at best, even for the hypothetically most vulnerable subpopulations. Mold spores are present in all indoor environments and cannot be eliminated from them. Normal building materials and furnishings provide ample nutrition for many species of molds, but they can grow and amplify indoors only when there is an adequate supply of moisture. Where mold grows indoors there is an inappropriate source of water that must be corrected before remediation of the mold colonization can succeed. Mold growth in the home, school, or office environment should not be tolerated because mold physically destroys the building materials on which it grows, mold growth is unsightly and may produce offensive odors, and mold is likely to sensitize and produce allergic responses in allergic individuals. Except for persons with severely impaired immune systems, indoor mold is not a source of fungal infections. Current scientific evidence does not support the proposition that human health has been adversely affected by inhaled mycotoxins in home, school, or office environments.

[Incidence and detection of fungi and eosinophilic granulocytes in chronic rhinosinusitis]

BACKGROUND

Chronic Rhinosinusitis (CRS) is the most common chronic disease in the United States. Though for Europe no data are available, we have to assume that the situation is similar. Although the disease is defined very well by clinical symptoms, up to date the etiology and pathogenesis of chronic rhinosinusitis are unknown. CRS is considered to be multifactorial, with thickening of the mucosa and formation of polyps as an end stage of the disease. Treatment of choice includes corticosteroids and/or endoscopic or microscopic surgery. Antibiotics only help, if there is an acute bacterial exacerbation of the disease. They are not able to cure chronic rhinosinusitis per se. In 1999 Mayo Clinic researchers published data concerning the incidence of so-called "allergic" fungal sinusitis (AFS) in their patients suffering from chronic rhinosinusitis, demonstrating the majority of patients investigated presenting those criteria. Our own initial data from 2000 confirmed their findings.

MATERIAL AND METHODS

In an open prospective study fungal cultures were obtained from nasal mucus of 238 consecutive patients suffering from CRS. As control group acted 23 members of our staff, who did not show any evidence for CRS. In addition, in 37 CRS patients surgical specimens (mucus and tissue) were investigated histologically for evidence of eosinophilic granulocytes and fungal elements.

RESULTS

Using new techniques for fungal detection in culture and histology as proposed by Mayo Clinic researchers, positive detection of fungal cultures of the mucus of our CRS patients developed from 7 % in the past up to 87 % at present. 91.3 % of our control group yielded a positive result in fungal culture. Histologically, eosinophilic clusters were evident in 94.6 % and fungal elements were detected in 75.5 % within the mucus of 37 surgical CRS patients. Overall, 89.2 % of our surgical patients thus fulfilled the criteria of so-called AFS. Compared to our findings in the past, our latest results show an increase of 80 % in detection of fungal elements in our CRS patients. In all we were able to identify 654 positive fungal cultures in 238 CRS patients and 23 healthy controls respectively. 88 different genera grew, with 2.4 different species per patient and 3.1 different species per healthy control, on average.

CONCLUSION

Utilizing new techniques of fungal culturing out of the mucus of CRS patients and healthy controls, the number of positive fungal cultures increased dramatically from 7 % to 87 % in our patients and 91.3 % in healthy controls respectively. To obtain these results it is crucial to perform special techniques of mucus sampling and pretreatment for culturing as well as for histological investigations. Our results show, that with suitable techniques fungi can be identified in almost everybody's nose, CRS patient or healthy. When inhaled, those airborne fungi are only "in transit" through the nose. Positive fungal cultures from nasal secretion therefore have to be considered normal findings. The reason for this delayed recognition has to be attributed to our inadequate methods in the past. In contrast to healthy controls, clusters of eosinophils and fungal elements are present simultaneously within the mucus of CRS patients and appear to be a marker of the disease.

Diagnosis of fungal diseases

In this chapter, we focus on diagnostic laboratory methods that are necessary and suitable for providing physicians with a timely and accurate diagnosis of fungal diseases. After discussing some pre-analytical aspects, the complete set of methods, i.e., microscopy, histopathology, culture, antigen detection, DNA detection, and antibody detection, is concisely described. Identification techniques depend on the fungal group involved. Therefore, separate paragraphs are dedicated to the identification of yeasts and filamentous fungi, which include moulds, dermatophytes, and dimorphic fungi.

Systemic mycoses in the immunocompromised host: an update in antifungal therapy

Despite significant advances in the management of immunosuppressed patients, invasive fungal infections remain an important life-threatening complication. In the last decade several new antifungal agents, including compounds in pre-existing classes (new generation of triazoles, polyenes in lipid formulations) and novel classes of antifungals with a unique mechanism of action (echinocandins), have been introduced in clinical practice. Ongoing and future studies will determine their exact role in the management of different mycoses. The acceleration of antifungal drug discovery offers promise for the management of these difficult to treat opportunistic infections.

Growth hormone and mannan-binding lectin: emerging evidence for hormonal regulation of humoral innate immunity

An increasing number of studies in animals and humans indicate that growth hormone (GH) and insulin-like growth factor-I (IGF-I) modulate immune function. It was recently reported that, surprisingly, GH therapy increased the mortality in critically ill patients. The excessive mortality was almost entirely due to septic shock or multi-organ failure, which could suggest that a GH-induced modulation of immune function was involved. Mannan-binding lectin (MBL) is a plasma protein that plays an important role in innate immunity through activation of the complement cascade and inflammation following binding to carbohydrate structures. The serum concentration of MBL is subject to large between-subjects differences, which primarily are caused by genetic factors. However, mounting evidence supports a significant influence from growth hormone on MBL levels. In the present review, we focus on the function of MBL, on the influence of growth hormone on MBL levels, and on the possible clinical consequences of this new link between the endocrine and the immune system.

Toll-like receptors and their role in experimental models of microbial infection

Effective host defense against microbial infection depends upon prompt recognition of pathogens, activation of immediate containment measures, and ultimately the generation of a specific and definitive adaptive immune response. The innate immune system of the host is responsible for providing constant surveillance against infection; when confronted by pathogens it deploys a series of rapidly acting antimicrobial effectors while simultaneously instructing the adaptive immune system as to the nature and context of the infectious threat. Pathogen recognition and activation of innate immunity is mediated by members of the Toll-like receptor (TLR) family through detection of conserved microbial structures that are absent from the host. Experimental models of infection using TLR-deficient mice, as well as limited human studies, have clearly demonstrated the critical role of TLRs in host defense against most major groups of mammalian pathogens.

Summary: future directions in antifungal therapy

The development of strategies for the prevention and treatment of invasive fungal infection is reviewed. The optimal deployment of antifungal agents is impeded by delays in diagnosis, which reflect the need for tissue samples for histopathology and/or the slow growth of organisms in culture for identification. Further, the lack of rapid and standardized methods for antimicrobial susceptibility testing has been identified as a major hurdle to optimal management. It is likely that combinations of antifungal agents will be needed to accelerate the clinical response to therapy (i.e., killing of fungus in tissues more rapidly). Such combinations may have the capacity to reduce toxicity while providing either true additive or synergistic activities or improved pharmacokinetics to "target" infection in multiple sites. Preclinical studies and clinical trials will begin to identify candidate therapies for invasive fungal infections in transplantation.

Eosinophilic fungal rhinosinusitis of the lacrimal sac

OBJECTIVES/HYPOTHESIS

Chronic sinusitis is a condition affecting millions of individuals each year. Recent findings indicate that chronic rhinosinusitis is a response to fungi mediated by the eosinophil in some of these individuals. We report a case of eosinophilic fungal rhinosinusitis of the lacrimal sac, an entity not previously reported.

STUDY DESIGN

Case report.

METHODS

A 69-year-old man presented with a 1-cm cystic lesion in the right-side medial canthal region. This lesion was fluctuant, and mucoid material was freely expressed from the medial canthal area. Endoscopic examination revealed bilateral nasal polyps anteriorly and superiorly with mucopurulent drainage from both maxillary sinuses. He had undergone three prior sinus surgeries and two prior lacrimal cannulations elsewhere. A computed tomography scan showed opacification of both maxillary sinuses, ethmoid sinuses, and the left sphenoid sinus and moderate thickening in the frontal sinuses. There was significant soft tissue prominence in the area of both lacrimal fossae with erosion into the medial orbit. The patient underwent bilateral endoscopic revision ethmoidectomies, middle meatal antrostomies, sphenoidotomies, frontal sinusotomies, and endoscopic right-side dacryocystorhinostomy at the Department of Otorhinolaryngology, Mayo Clinic (Rochester, MN).

RESULTS

At the time of surgery, massive amounts of thick mucoid material were aspirated from both lacrimal regions. The aspiration of the lacrimal duct on the left side was sufficient treatment, whereas the dacryocystorhinostomy was necessary to decompress the cyst of the face on the right side. The material aspirated was allergic mucin, and the patient met the criteria for diagnosing eosinophilic fungal rhinosinusitis. The patient was started on a regimen of antifungal nasal irrigations postoperatively and has done well in follow-up.

CONCLUSIONS

Although never previously reported, eosinophilic fungal rhinosinusitis can occur in the lacrimal sac. It is important to recognize this so that the underlying disease process can be treated appropriately.

Computed tomographic findings in patients with invasive fungal sinusitis

OBJECTIVE

To determine the radiographic findings of computed tomographic (CT) imaging most suggestive of invasive fungal sinusitis (IFS) in an immunocompromised patient population.

DESIGN

A retrospective review of patients with a diagnosis of IFS reached with CT and confirmed by histopathologic evaluation.

SETTING

An academic tertiary care hospital.

PATIENTS

Twenty-three immunocompromised patients with confirmed IFS and preoperative CT imaging. Controls were 10 patients with acute myelocytic leukemia and CT evidence of sinusitis but no history of IFS.

OUTCOME MEASURES

The CT scans were reviewed to identify factors predictive of invasive fungal disease. Parameters evaluated were nasal cavity and sinus soft tissue thickening, the presence of air-fluid levels, bone erosion, extrasinus extension, and unilateral or bilateral nasal cavity and sinus involvement.

RESULTS

The CT findings included severe soft tissue edema of the nasal cavity mucosa (turbinates, lateral nasal wall and floor, and septum) in 21 of the 23 patients, sinus mucoperiosteal thickening in 21, bone erosion in 8, orbital invasion in 6, facial soft tissue swelling in 5, and retroantral fat pad thickening in 2. Two patients had air-fluid levels. No patients had intracranial involvement. Unilateral involvement was found in 21 patients, and bilateral involvement in 2. Review of the control group revealed only mild soft tissue edema of the nasal cavity in 2 (P<.001), unilateral involvement in 2 (P<.001), and evidence of bone erosion or extrasinus soft tissue involvement in none.

CONCLUSIONS

Most patients do not have classic CT findings of bone erosion or extrasinus extension in the early course of IFS. We found that severe unilateral thickening of the nasal cavity mucosa was the most consistent finding on CT suggestive of underlying IFS, occurring much more frequently in immunocompromised patients with IFS than without IFS. Even though severe nasal cavity soft tissue thickening is much more common in IFS, this is a nonspecific finding that can be seen, to a lesser degree, in all forms of rhinosinusitis. Therefore, the clinician cannot rely solely on CT imaging and must maintain a high index of suspicion when evaluating immunocompromised patients to establish a prompt diagnosis. Early nasal endoscopy with biopsy and initiation of appropriate therapy are necessary to improve prognosis.

Relevance of airborne fungi and their secondary metabolites for environmental, occupational and indoor hygiene

Airborne fungal contaminants are increasingly gaining importance in view of health hazards caused by the spores themselves or by microbial metabolites. In addition to the risk for infection, the allergenic and toxigenic properties, as well as the inflammatory effects are discussed in this review as possible health impacts of bioaerosols. A major problem is the lack of threshold values for pathogenic and non-pathogenic fungi, both in the workplace and in outdoor air. While the relevance of mycotoxins has been intensely studied in connection with contamination of food and feed, the possible respiratory uptake of mycotoxins from the air has so far not been sufficiently taken into account. Toxic secondary metabolites are expected to be present in airborne spores, and may thus occur in airborne dust and bioaerosols. Potential health risks cannot be estimated reliably unless exposure to mycotoxins is determined qualitatively and quantitatively. Microbial volatile organic compounds (MVOC) have been suggested to affect human health, causing lethargy, headache, and irritation of the eyes and mucous membranes of the nose and throat. The production of MVOC by fungi has been discussed in connection with domestic indoor microbial pollution, but the relevance of fungal metabolites in working environments remains insufficiently studied.

[Paecilomyces lilacinus systemic infection in an immunocompromised child]

The incidence of systemic fungal infections increased during the last two decades. Rare fungi, such as Mucor, Fusarium and Paecilomyces, are emerging as causes of systemic fungal infections in immunocompromised hosts. There are reports of cutaneous infections, endophthalmitis, keratitis, sinusitis, neuropathy and fungemia in immunocompromised and immunocompetent adult patients. We report a 5 years old neutropenic patient with acute myeloid leukemia treated with multiple courses of chemotherapy, with a fungemia caused by Paecilomyces lilacinus (PL). His initial clinical course was characterized by fever, skin lesions, respiratory distress and shock. Blood and bone marrow cultures were positive. The patient was treated with amphotericin B and itraconazole with a good clinical response.

Phaeohyphomycosis Caused byChaetomium Globosumin an Allogeneic Bone Marrow Transplant Recipient

Bone marrow transplant recipients are highly susceptible to opportunistic fungal infections. This is the report, of the first case of a Chaetomium systemic infection described in Brazil. A 34 year-old patient with chronic myeloid leukemia underwent an allogeneic sibling matched bone marrow transplant. Seven months later, he developed systemic infection with enlargement of the axillary and cervical lymph nodes. Culture of the aspirates from both lymph nodes yielded Chaetomium globosum. The infection was successfully treated with amphotericin B. The increasing population of immunosupressed patients requires a careful microbiologic investigation for uncommon fungal infections.

Mould specific IgG antibodies connected with sinusitis in teachers of mould damaged school: a two-year follow-up study

OBJECTIVES

The aim of this study was to describe the relationship between mould exposure induced by moisture damage and mould specific immunoglobulin G antibodies to 20 common mould species and their association with respiratory diseases.

MATERIALS AND METHODS

Mould specific immunoglobulin G (IgG) antibodies were monitored in teachers in a follow-up after an extensive mould remediation process in school buildings. IgG antibodies to 20 different microbes were determined from the sera of 26 teachers (19 exposed and 7 references) by enzyme-linked immunosorbent assay (ELISA). The serum samples were drawn twice, firstly at the completion of the remediation in the spring of 1997 and secondly, two years later in the spring of 1999. Health data was collected with self-administered questionnaires.

RESULTS

No statistical differences were found in the overall concentrations of 20 mould-specific IgG-antibodies between the study and control groups at the beginning of the study. An association between sinusitis and elevated mould-specific IgG-levels forAspergillus fumigatus, Aspergillus versicolor, Aureobasidium pullulans, Chaetomium globosum, Cladosporium cladosporioides, Phialophora bubakii, Rhodotorula glutinis, Sporobolomyces salmonicolor, Stachybotrys atra, and Tritirachium roseum was found in the study group.

CONCLUSIONS

In a two-year follow-up the total concentration of the IgG antibodies for Tr. toseum was lower at the end than at the beginning of the follow-up and this remained significant for the group of teachers with sinusitis. The decrease in mould specific IgG to Cl. cladosporioides, Geotrichum candidum, Ph. bubakii and Rhizopus nigricans was associated with bronchitis. According to our knowledge, this is the first study in which the association between elevated mould specific IgG antibodies and sinusitis was found in the school environment.

Differential cytokine pattern in the spleens and livers of BALB/c mice infected with Penicillium marneffei: protective role of gamma interferon

Penicillium marneffei is an intracellular opportunistic fungus causing invasive mycosis in AIDS patients. T cells and macrophages are important for protection in vivo. However, the role of T-cell cytokines in the immune response against P. marneffei is still unknown. We studied by semiquantitative reverse transcription-PCR and biological assays the patterns of expression of Th1 and Th2 cytokines in the organs of wild-type (wt) and gamma interferon (IFN-gamma) knockout (GKO) mice infected intravenously with P. marneffei conidia. At 3 x 10(5) conidia/mouse, a self-limiting infection developed in wt BALB/c mice, whereas all GKO mice died at day 18 postinoculation. Splenic and hepatic granulomas were present in wt mice, whereas disorganized masses of macrophages and yeast cells were detected in GKO mice. The infection resolved faster in the spleens than in the livers of wt mice and was associated with the local expression of type 1 cytokines (high levels of interleukin-12 [IL-12] and IFN-gamma) but not type 2 cytokines (low levels of IL-4 and IL-10). Conversely, both type 1 and type 2 cytokines were detected in the livers of wt animals. Disregulation of the cytokine profile was seen in the spleens but not in the livers of GKO mice. The inducible nitric oxide synthase mRNA level was low and the TNF-alpha level was high in both spleens and livers of GKO mice compared to wt mice. These data suggest that the polarization of a protective type 1 immune response against P. marneffei is regulated at the level of individual organs and that the absence of IFN-gamma is crucial for the activation of fungicidal macrophages and the development of granulomas.