Unusual manifestations of histoplasmosis

Unusual manifestation of pulmonary Verruconis gallopava infection with synchronous reactive pericardial effusion in a non-transplanted patient

Verruconis gallopava is an emerging causative agent in solid organ transplant patients, increasing in prevalence both in non-transplanted patients and also in immunocompetent ones, albeit rarely. In this case report, we describe an unusual V. gallopava infection in a patient with steroid-dependent autoimmune haemolytic anaemia. The chest CT scan revealed a mass-like consolidation in the superior segment of the right lower lobe, and bronchoscopic examination confirmed V. gallopava from bronchoalveolar lavage. The histopathology showed non-necrotising granulomatous inflammation concurrent with septate-pigmented hyphae, which is compatible with dematiaceous fungi. After 3 weeks of posaconazole treatment, the patient developed a new pericardial effusion. Further investigations, including culture, cytology and histopathology, yielded negative results, leading to suspicion of reactive pericardial effusion associated with V. gallopava pulmonary infection. The patient received antifungal therapy for 9 months, after which a follow-up chest CT scan showed complete resolution of consolidation and pericardial effusion.

Histoplasmosis Myocarditis in an Immunocompetent Host After a Recreational Mud Run

Mud runs are an increasingly popular recreational fitness activity across the United States, combining a running race through an obstacle course with submersion in mud. Recent reports estimate 4 million people have participated in these types of events over the last 5 years. We describe an atypical case of myocarditis and multiorgan failure from disseminated histoplasmosis in a previously healthy pediatric patient, likely acquired during participation in a mud run. Although cases of histoplasmosis-associated endocarditis and pericarditis have been reported in the literature, cases of histoplasmosis myocarditis are rare.

Fulminant Cryptococcus neoformans infection with fatal pericardial tamponade in a patient with chronic myelomonocytic leukaemia who was treated with ruxolitinib: Case report and review of fungal pericarditis

Cryptococcus neoformans is a saprophytic fungal pathogen that can cause serious illness in immune-compromised hosts and it presents with a wide variety of clinical symptoms. We present a fatal case of fulminant C. neoformans infection presenting as pericardial tamponade in a 71-year-old male with chronic myelomonocytic leukaemia undergoing chemotherapy with the JAK-STAT inhibitor ruxolitinib. We also review the published cases of fungal pericarditis/tamponade. In addition to illustrating an atypical presentation of C. neoformans, this case highlights the risk for opportunistic fungal infections in patients with haematological malignancies, especially the ones treated with small molecule kinase inhibitors.

Stochastic optical reconstruction microscopy-based relative localization analysis (STORM-RLA) for quantitative nanoscale assessment of spatial protein organization

Stochastic optical reconstruction microscopy–based relative localization analysis (STORM-RLA) is a novel method for the high-throughput quantification of spatial protein organization from three-dimensional single-molecule positional data.

The spatial association between proteins is crucial to understanding how they function in biological systems. Colocalization analysis of fluorescence microscopy images is widely used to assess this. However, colocalization analysis performed on two-dimensional images with diffraction-limited resolution merely indicates that the proteins are within 200–300 nm of each other in the xy-plane and within 500–700 nm of each other along the z-axis. Here we demonstrate a novel three-dimensional quantitative analysis applicable to single-molecule positional data: stochastic optical reconstruction microscopy–based relative localization analysis (STORM-RLA). This method offers significant advantages: 1) STORM imaging affords 20-nm resolution in the xy-plane and <50 nm along the z-axis; 2) STORM-RLA provides a quantitative assessment of the frequency and degree of overlap between clusters of colabeled proteins; and 3) STORM-RLA also calculates the precise distances between both overlapping and nonoverlapping clusters in three dimensions. Thus STORM-RLA represents a significant advance in the high-throughput quantitative assessment of the spatial organization of proteins.

Histoplasma capsulatum: An Unusual Case of Pericardial Effusion and Coarctation of the Aorta

Histoplasma capsulatum is a fungus that is endemic in many parts of the world and can present with a wide variety of symptoms. Here we present a case of a previously healthy 19-year-old female who presented with shortness of breath. She was found to have a right lung mass and coarctation of the aorta on computed tomography imaging. Pathology revealed granuloma caused by Histoplasma capsulatum. She later developed massive pericardial effusion, requiring emergent pericardiocentesis. She was treated with anti-fungal therapy and recovered well. This case illustrates an unusual presentation of newly diagnosed coarctation of the aorta complicated by Histoplasma pericardial effusion. Imaging and pathology slides are reviewed.

Primary leptomeningeal melanocytosis presenting as chronic meningitis

We report a patient with primary leptomeningeal melanocytosis presenting as chronic meningitis. A previously healthy 27-year-old man presented with 2 months of severe headaches and photophobia. A lumbar puncture was notable for a highly elevated cerebrospinal fluid (CSF) protein level without pleocytosis. Imaging at the time of admission suggested only meningitis without the presence of parenchymal lesions. On the basis of the CSF findings, early meningeal biopsy was performed, leading to the diagnosis of a meningeal melanocytic neoplasm. Early meningeal biopsy should be considered in patients with meningitis when the CSF profile suggests the possibility of a central nervous system neoplasm.

Cutaneous manifestations of endemic mycoses

All of the endemic mycoses have cutaneous and mucocutaneous manifestations that are most commonly seen when patients have disseminated infection. Biopsy of skin lesions is simple and safe and can assist in making a timely diagnosis of disseminated infection. Primary cutaneous inoculation infection has been reported with all of the endemic mycoses, but is rare. In this situation, a nodule or ulcer occurs at the inoculation site, is often accompanied by lymphangitis and regional lymphadenopathy, and systemic symptoms and signs as almost always absent. Mucosal lesions are common with disseminated histoplasmosis, but also have been described in patients who have disseminated blastomycosis and coccidioidomycosis. Biopsy is essential to rule out cancer and allows a rapid diagnosis of the endemic fungal infection.

Cell mediated immunity to fungi: a reassessment

Protective immunity against fungal pathogens is achieved by the integration of two distinct arms of the immune system, the innate and adaptive responses. Innate and adaptive immune responses are intimately linked and controlled by sets of molecules and receptors that act to generate the most effective form of immunity for protection against fungal pathogens. The decision of how to respond will still be primarily determined by interactions between pathogens and cells of the innate immune system, but the actions of T cells will feed back into this dynamic equilibrium to regulate the balance between tolerogenic and inflammatory responses. In the last two decades, the immunopathogenesis of fungal infections and fungal diseases was explained primarily in terms of Th1/Th2 balance. Although Th1 responses driven by the IL-12/IFN-gamma axis are central to protection against fungi, other cytokines and T cell-dependent pathways have come of age. The newly described Th17 developmental pathway may play an inflammatory role previously attributed to uncontrolled Th1 responses and serves to accommodate the seemingly paradoxical association of chronic inflammatory responses with fungal persistence in the face of an ongoing inflammation. Regulatory T cells in their capacity to inhibit aspects of innate and adaptive antifungal immunity have become an integral component of immune resistance to fungi, and provide the host with immune defense mechanisms adequate for protection, without necessarily eliminating fungal pathogens which would impair immune memory--or causing an unacceptable level of tissue damage. The enzyme indoleamine 2,3-dioxygenase and tryptophan metabolites contribute to immune homeostasis by inducing Tregs and taming overzealous or heightened inflammatory responses.

Two specific strains of Histoplasma capsulatum causing mucocutaneous manifestations of histoplasmosis: preliminary analysis of a frequent manifestation of histoplasmosis in southern Brazil

OBJECTIVES

Skin lesions, uncommon in US cases (<10%), occur in 38-85% of cases reported from Latin America. Although these differences may reflect reporting bias, delayed diagnosis, or differences in host immune response among different ethnic groups, they also could result from genetic differences changing the pathobiology of the organism. It is possible that genetic differences among strains of H. capsulatum may influence the pathogenesis and clinical manifestations of histoplasmosis.

METHODS

We examined the clinical features of patients with mucocutaneous manifestations of histoplasmosis and performed genetic analysis based on nucleotide sequence variations in the internal transcribed spacer regions of rRNA genes of H. capsulatum isolates of patients. Two pairs of PCR primers were designed to develop and amplify the ITS regions of H. capsulatum, 5'-TACCCGGCCACCCTTGTCTA-3' and 5'-AGCGGGTGGCAAAGCCC-3'. These primers were based on the ITS sequence of Ajellomyces capsulatus, the ascomycetous teleomorph form of H. capsulatum, deposited in the GenBank (accession number U18363). Eight patients attending a tertiary-care hospital in southern Brazil were enrolled into the study. All case patients had skin cultures growing H. capsulatum at the mycology laboratory.

RESULTS

Six of eight (75%) patients were HIV-positive and presented involvement of multiples organs by H. capsulatum. Two HIV-negative patients did not present evidence of involvement of other organs besides mucosa and skin. ITS sequencing of a DNA H. capsulatum fragment of 485-bp from isolates of 8 patients revealed two distinct strains. The 2 distinct fragments (Hc1, Hc2) differed from each other at 7 positions in the ITS regions. They were identical to strains of H. capsulatum isolated in patients from Colombia and Argentina, but different from strains isolated in US. Hc1 and Hc2 were isolated in 5 patients and 3 patients, respectively, with mucocutaneous manifestations of histoplasmosis. Both Hc1 and Hc2 strains were isolated in HIV-infected and non-HIV-infected patients.

CONCLUSIONS

Mucocutaneous manifestations of histoplasmosis, which are frequently seen in Brazilian patients were caused by 2 specific strains in our institution. Those strains have been isolated in patients with these particular clinical features of histoplasmosis in Latin America. Our study suggests that unique pathogenic characteristics among the Latin American species of H. capsulatum might explain its increased dermatotropism.

Literature review and case histories of Histoplasma capsulatum var. duboisii infections in HIV-infected patients

African histoplasmosis during HIV infection is rare.

African histoplasmosis caused by Histoplasma capsulatum var. duboisii is an invasive fungal infection endemic in central and west Africa. Most of its ecology and pathogenesis remain unknown. H. capsulatum var. capsulatum is an AIDS-defining opportunistic infection in HIV-infected patients who are living in or have traveled to histoplasmosis-endemic areas. In contrast, reports concerning African histoplasmosis during HIV infection are rare, although both pathogens coexist in those regions. We report 3 cases of imported African histoplasmosis diagnosed in France in HIV-infected patients and a literature review on similar cases.

Mucocutaneous manifestations of disseminated histoplasmosis in patients with acquired immunodeficiency syndrome: particular aspects in a Latin-American population

BACKGROUND

Mucocutaneous lesions in human immunodeficiency virus (HIV)-infected patients with disseminated histoplasmosis have a wide spectrum of clinical manifestations, making its diagnosis difficult. Studies have been restricted to case reports and series with small numbers of patients not specifically focusing on the dermatological aspects of histoplasmosis.

AIMS

To describe the characteristics of mucocutaneous lesions of disseminated histoplasmosis in HIV-infected patients.

METHODS

A retrospective and prospective study was conducted on 36 HIV-infected patients with mucocutaneous histoplasmosis in a tertiary-care hospital in Brazil.

RESULTS

Mucocutaneous histoplasmosis was diagnosed by histopathology in 33 of the 36 patients (91%) and/or culture in 23 (64%). Their CD4+ cell counts ranged from 2 to 103 cells/mm(3). The average number of different morphological types of lesions was three per patient. Despite the variability of the lesions, papules (50%), crusted papules (64%) and oral mucosal erosions and/or ulcers (58%) were the most frequent dermatological lesions. A diffuse pattern of distribution of the skin lesions was found in 58% of the cases. There was significant association between the CD4+ cell counts and the morphological variability of lesions per patient. Variation in the lesions seemed to be associated with higher CD4+ cell counts.

CONCLUSION

Doctors caring for HIV-infected patients should be aware of the wide spectrum of dermatological lesions observed in disseminated histoplasmosis and the importance of detecting and isolating the fungus in mucocutaneous tissues.

Increased Incidence of Disseminated Histoplasmosis Following Highly Active Antiretroviral Therapy Initiation

To determine whether the initiation of highly active antiretroviral therapy (HAART) had any influence on the incidence of disseminated histoplasmosis, a retrospective cohort study was performed on 1551 patients followed for up to 12 years. After controlling for CD4 counts, age, and sex, patients taking HAART for 2 months or less were more likely to develop disseminated histoplasmosis than untreated patients (respectively, hazard ratio, 3.7 [95% confidence interval, 1.57-8.7]; P = 0.003). In contrast, after 6 months of HAART, treated patients were less likely to develop disseminated histoplasmosis than untreated patients (hazard ratio, 0.6 [95% confidence interval, 0.37-0.98], P = 0.04). This increased incidence suggests that the initiation of HAART and the subsequent immune reconstitution may reveal undiagnosed latent disseminated histoplasmosis.

Chronic meningitis

Chronic meningitis is a syndrome commonly defined by the presence of continuously persistent meningeal inflammation for at least 4 weeks. Presenting neurologic features are often nonspecific, and the list of differential diagnoses is broad. Despite the development of modern molecular diagnostic methods, establishing a specific cause may challenge the acumen of the treating neurologist with clues to the diagnosis residing outside the nervous system and requiring focused investigation. This review discusses selected etiologies illustrating issues in diagnosis and etiologic categories to be considered in the evaluation of this challenging syndrome.