The gamut of paracoccidioidomycosis

Paracoccidioidomycosis: What We Know and What Is New in Epidemiology, Diagnosis, and Treatment

Paracoccidioidomycosis (PCM) is a systemic mycosis endemic to Latin America caused by thermodimorphic fungi of the genus Paracoccidioides. In the last two decades, enhanced understanding of the phylogenetic species concept and molecular variations has led to changes in this genus’ taxonomic classification. Although the impact of the new species on clinical presentation and treatment remains unclear, they can influence diagnosis when serological methods are employed. Further, although the infection is usually acquired in rural areas, the symptoms may manifest years or decades later when the patient might be living in the city or even in another country outside the endemic region. Brazil accounts for 80% of PCM cases worldwide, and its incidence is rising in the northern part of the country (Amazon region), owing to new settlements and deforestation, whereas it is decreasing in the south, owing to agriculture mechanization and urbanization. Clusters of the acute/subacute form are also emerging in areas with major human intervention and climate change. Advances in diagnostic methods (molecular and immunological techniques and biomarkers) remain scarce, and even the reference center’s diagnostics are based mainly on direct microscopic examination. Classical imaging findings in the lungs include interstitial bilateral infiltrates, and eventually, enlargement or calcification of adrenals and intraparenchymal central nervous system lesions are also present. Besides itraconazole, cotrimoxazole, and amphotericin B, new azoles may be an alternative when the previous ones are not tolerated, although few studies have investigated their use in treating PCM.

Pathogenesis and Classification of Paracocidioidomycosis: New Insights From Old Good Stuff

Different classifications of paracoccidioidomycosis emerged since its discovery in 1908, culminating in the proposition of a simplified and consensual one in 1987. However, by revisiting these classifications, case reports, or case series from which the authors based their own, we found many patients who did not fit in either the 1987 classification or in the correspondent natural history/pathogenesis view. In this report, the concepts of paracoccidioidomycosis infection, primary pulmonary paracoccidioidomycosis (PP-PCM), and other subclinical forms of PCM are reassessed. A classification is proposed to encompass all these subtle but distinct outcomes. I suggest a continuum between the PP-PCM and the overt chronic form of disease, and not the current view of quiescent foci, frozen in time and suddenly reactivated for unknown reasons. Failure to fully resolve the infection in its initial stages is a conceivable hypothesis for the chronic form. The proposed clinical classification might offer new insights to better characterize and manage PCM patients.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Complex nasal reconstruction after paracoccidioidomycosis infection--Case report

Paracoccidioidomycosis is an infectious disease whose etiological agent belongs to the Paracoccidioides genus. Although it affects primarily the lungs, it can spread to other tissues, including the skin and mucous membranes. Despite the clinical treatment for this disease, scarring can produce sequelae, manifesting as anatomical and functional deformities of the face. We present a case of extensive, nasal unaesthetic and functional sequelae resulting from paracoccidioidomycosis, reconstructed using the paramedian forehead flap in three stages, through the regional unit principles.

Pleural effusion an unusual feature of paracoccidioidomycosis: report of two new cases with a systematic review of the literature

Paracoccidioidomycosis (PCM) is an endemic disease restricted geographically to Latin America. Brazil accounts for about 80 % of the reported cases, and lungs are most frequently affected. A suggestive radiograph of PCM may only be seen late in the course of the disease. At the beginning, it mimics tuberculosis. On the other hand, pleural effusion on rare occasions has been reported in PCM. For this reason, we report two cases with such uncommon manifestation. Our first patient presented pleural effusion probably caused by PCM (a previously unreported cause of lung mass accompanied by effusion); the second with proved pleural effusion due to PCM. A systematic review of the literature was done.

Structural and topographic dynamics of pulmonary histopathology and local cytokine profiles in Paracoccidioides brasiliensis conidia-infected mice

BACKGROUND

Paracoccidioidomycosis (PCM), an endemic systemic mycosis caused by the fungus Paracoccidioides brasiliensis (Pb), usually results in severe lung damage in patients.

METHODS AND FINDINGS

Considering the difficulties to sequentially study the infection in humans, this work was done in mice inoculated intranasally with infective Pb-conidia. Lungs of control and Pb-infected mice were studied after 2-hours, 4, 8, 12 and 16-weeks post-infection (p.i) in order to define histopathologic patterns of pulmonary lesions, multiplex-cytokine profiles and their dynamics during the course of this mycosis. Besides the nodular/granulomatous lesions previously informed, results revealed additional non-formerly described lung abnormalities, such as periarterial sheath inflammation and pseudotumoral masses. The following chronologic stages occurring during the course of the experimental infection were defined: Stage one (2-hours p.i): mild septal infiltration composed by neutrophils and macrophages accompanied by an intense "cytokine burst" represented by significant increases in IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL12p70, IL-13, IL-17, Eotaxin, G-CSF, MCP1, MIP1α, GM-CSF, IFN-γ, MIP1β and TNFα levels. Stage two (4-weeks p.i): presence of nodules, evidence of incipient periarterial- and intense but disperse parenchymal- inflammation, abnormalities that continued to be accompanied by hyper-secretion of those cytokines and chemokines mentioned in the first stage of infection. Stages three and four (8 and 12-weeks p.i.): fungal proliferation, inflammation and collagenesis reached their highest intensity with particular involvement of the periarterial space. Paradoxically, lung cytokines and chemokines were down-regulated with significant decreases in IL-2,IL-3,IL-5,IL-9,IL-13,IL-15,GM-CSF,IFN-γ,MIP1β and TNFα. Stage five (16-weeks p.i.): inflammation decreased becoming limited to the pseudotumoral masses and was accompanied by a "silent" cytokine response, except for PDGF, MIG, RANTES and IL12p40 which remained up-regulated for the duration of the experiment.

CONCLUSIONS

Results of this study identified both classic and novel patterns corresponding to histopathologic and immunologic responses occurring during the course of experimental PCM.

Simon Bolivar's medical labyrinth: an infectious diseases conundrum

According to history books, tuberculosis was responsible for the death of Simon Bolivar at the age of 47 years in 1830. The results of an autopsy performed by Alexandre Prospère Révérend, the French physician who cared for him during the terminal phase of his illness, have long been regarded as proof of the diagnosis. On careful reanalysis of Bolivar's medical history and post mortem examination, we reach a different conclusion. On the basis of several critical clinical, epidemiological, and pathological features of his fatal disorder, we conclude that either paracoccidioidomycosis or bacterial bronchiectasis complicating chronic arsenic intoxication was more likely responsible for his death than was tuberculous "consumption."

Chronic diarrhea and pancolitis caused by paracoccidioidomycosis: a case report

South American blastomycosis is a systemic micosis caused by infection with Paracoccidioides brasiliensis. The most frequently affected sites are the lower lip buccal mucous membrane, palate, tongue, sublingual region, lymph glands, and lungs. However, colonic involvement is not a common expression of Paracoccidioidomycosis. We report a case of chronic diarrhea and pancolitis caused by Paracoccidioidomycosis with fatal outcome.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

Infiltrative myelopathy by paracoccidioidomycosis. A review and report of nine cases with emphasis on bone marrow morphology

AIMS

To report nine additional well-defined cases with infiltrative myelopathy by paracoccidioidomycosis (PCM), to describe the specific lesions and infection-related stromal abnormalities, to review the literature on this type of involvement and to introduce a new cause of granulomatous lesions of bone marrow.

METHODS AND RESULTS

Different bone marrow specimens were studied (aspirated smears, aspirated clots, biopsy imprints and biopsies) from nine patients with acute or subacute forms of PCM known to have PCM infiltrative myelopathy.

CONCLUSIONS

The biopsy specimens were the best for demonstrating bone marrow involvement by PCM. The lesions varied from compact and focal granulomas with few fungal cells to numerous disseminated fungal cells within a loose granulomatous inflammatory reaction, with a continuum between these extremes suggesting a spectrum of immune response to the fungi. Other findings such as bone marrow fibrosis, parenchymal coagulative necrosis and bone necrosis were also observed in the affected areas.

The glyceraldehyde-3-phosphate dehydrogenase homologue is differentially regulated in phases of Paracoccidioides brasiliensis: molecular and phylogenetic analysis

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays important roles in various cellular processes. Here we report the sequence and analysis of a novel developmentally regulated gene and cDNA (Pbgadph), encoding a GAPDH homologue (PbGAPDH), of the pathogenic dimorphic fungus Paracoccidioides brasiliensis. We have analyzed the protein, the cDNA and genomic sequences to provide insights into the structure, function, and potential regulation of PbGAPDH. That Pbgapdh encodes PbGAPDH was demonstrated by micro-sequencing of the native protein homologue isolated from the fungus proteome. The deduced amino acid sequence of Pbgapdh showed identity to those of from other species (88-76%). Phylogenetic analysis indicated that GAPDH could be useful for the determination of evolutionary relationships. Expression of the Pbgapdh gene and the cognate protein were developmentally regulated in phases of P. brasiliensis, with a higher expression in the yeast parasitic phase and was induced during the transition from mycelium to yeast and decreased during the reverse process, transition from yeast to mycelium.

Differential expression of actin modulated by temperature in mycelial and yeast cells of Paracoccidioides brasiliensis

We used yeast and mycelial forms of Paracoccidioides brasiliensis to evaluate the effect of heat shock stress on actin expression. P. brasiliensis yeasts harvested during the exponential growth phase showed more expression of the actin mRNA when incubated at 40 degrees C than when incubated at 37 degrees C, the usual temperature at which these yeasts grow. In contrast, expression of actin mRNA was lower in yeasts incubated at 25 degrees C than in yeasts incubated at 37 degrees C. Mycelium harvested at 25 degrees C, an approximation of its normal growth temperature, and then exposed to 37 degrees C and 40 degrees C showed progressively higher expression of actin mRNA. Mycelial and yeast forms showed a similar pattern of response to exposure to supra-optimal temperatures: both showed the same increase in expression of actin. This suggests that actin may play a role not only in cellular differentiation but also in this species' rapid adaptive response to heat stress, a mechanism necessary to deal with a potentially hostile environment.

Asymptomatic presentation of chronic pulmonary paracoccidioidomycosis: case report and review

Asymptomatic presentations of chronic pulmonary paracoccidiodomycosis have been reported since 1959, usually published in case series of paracoccidiodomycosis. Incidental radiographic findings on chest roentgenogram led to diagnostic evaluation in these cases. An unusual case in a female patient is described, and 24 previously reported cases are reviewed.

Correlation of susceptibility of immature mice to fungal infection (blastomycosis) and effector cell function

Immature mice are highly susceptible to blastomycosis, which is similar to other mycoses and has parallels in humans. The murine susceptibility is noteworthy in that it persists beyond the development of resistance to other, nonfungal pathogens and the maturation of most immune functions. As the susceptibility to blastomycosis appeared to be related to an early event after infection, primary effector cell function was studied. We found that peritoneal inflammatory cells, enriched for neutrophils, from immature (3-week-old) mice killed nonphagocytizable Blastomyces dermatitidis cells less (25%) than did cells from mature (8-week) mice (70%) (P<0.01), a defect intrinsic to the neutrophils. This correlated with an impaired immature cell oxidative burst. Killing of phagocytizable Candida albicans was not significantly different, 73 versus 87%. Thioglycolate-elicited cells were more impaired; killing of B. dermatitidis was insignificant, and killing of C. albicans was more impaired in immature (16% killing) than in mature (45%) cells (P<0.02). Peripheral blood neutrophils from mature animals killed B. dermatitidis (41%) more than did those from immature animals (10%) (P<0.02); C. albicans was killed efficiently by both. Resting or activated peritoneal macrophages from both types of animals showed no differences in B. dermatitidis killing. These results suggest that the susceptibility of immature mice is related at least in part to the depressed capacity of their neutrophils to kill B. dermatitidis.

Morphological aspects of Paracoccidioides brasiliensis in lymph nodes: implications for the prolonged latency of paracoccidioidomycosis?

In order to determine if fungal morphology in tissues would furnish indications on the viability of Paracoccidioides brasiliensis yeast cells, lymph node biopsies from five patients with paracoccidioidomycosis, including one with residual circumscribed lesions, were examined. A program that allows transferring of microscopic images to the computer for further processing was used. In the four active cases, the infected lymph nodes had over 49% of healthy-looking yeast cells while in the case of the residual lesion, this figure was smaller (21%). The residual had a larger proportion of aberrant yeast cells, with predominance of shell-like, empty cells (33%) and crescent bodies (30%); balloon-like yeasts were also seen (16%). The last two types of cells were also seen in the active lesions, but in smaller proportions, < or = 8% and < or = 9%, respectively. The number of multiple budding yeast cells, which clearly demonstrate fungal viability, ranged 24-33% in active cases but was only 5% in the residual lesion. Although the number of biopsies examined is small, the results tend to indicate that the morphology of P. brasiliensis yeast cells in walled-off tissues is abnormal and that the number of viable elements is small. There might be a connection between these findings and the long latency period illustrated by those patients with paracoccidioidomycosis that have been diagnosed in non-endemic areas. Additionally, if P. brasiliensis yeast cells were to be subjected to the microaerophilic environment present in walled-off lesions, they would probably require a long time to multiply. Under these circumstances, the mycosis would also need many years to manifest.

[The diagnosis of severe disseminated paracoccidioidomycosis in a bone marrow aspirate: a case report]

Acute or chronic disseminated paracoccidioidomycosis can be associated with changes in blood and bone marrow cell counts, mainly in the severe forms of this disease. However, there are few reports about the microbiological confirmation of the mycosis in bone marrow tissue. The present report describes a case of an adult patient with severe chronic multifocal paracoccidioidomycosis, whose etiological diagnosis has been done by the microscopical exam and culture fo the bone marrow aspirate. The authors emphasize the importance of these exams as an alternative way for the diagnosis of suspected cases of severe paracoccidioidomycosis.

The pathology of fungal disease in the lung

The gross and histological appearance of pulmonary mycotic disease is rarely pathognomonic for a particular entity. Tissue obtained through an invasive procedure is usually necessary for a specific diagnosis. Pathological diagnosis is directed by the pattern of inflammation and based on the morphological identification of fungi. The interventional radiologist plays a critical role in the diagnosis of pulmonary mycoses by obtaining additional material for culture. An open and inquisitive collaboration between the radiologist and pathologist can improve diagnostic accuracy for both specialists.

Cutaneous manifestations of systemic mycoses

Systemic fungal diseases are primary pulmonary diseases caused by the dimorphic fungal pathogens, Blastomyces dermatitides, Coccidioides immitis. Histoplasma capsulatum, or Paracoccidioides brasiliensis. Infection occurs after inhalation of the infectious form of the fungus and may be acute, self-limited, or subclinical. Primary cutaneous infection occurs only after traumatic implantation of the fungus and is unusual. Erythema nodosum or erythema multiforme may accompany the acute form of the disease. Other cutaneous manifestations represent disseminated disease and, as such, require systemic antifungal therapy. Because cutaneous lesions have occurred coincidentally with other cutaneous pathologies, emphasis should be placed on a complete clinical history, physical examination, and diagnosis by histopathology and culture.

Paracoccidioidomycosis associated with acquired immunodeficiency syndrome. Report of seven cases

We report the clinical findings and evolution of seven patients (five men and two women), the majority of them intravenous drug users, with paracoccidioidomycosis associated to acquired immunodeficiency syndrome (AIDS). In four of the patients the paracoccidioidomycosis was restricted to the lung and in the three others was generalized with cutaneous involvement. Only two of them had lived recently in rural area, an indication of the possible reactivation of latent focal infection in the other five patients. The recognition of the role of cell-mediated immunity in host defense against Paracoccidioides brasiliensis leds to the prediction of a growing occurrence of the paracoccidioidomycosis-AIDS association in areas that are endemic for these diseases.

Estudio comparativo de la patogenicidad y la antigenicidad de 6 cepas de Paracoccidioides brasiliensis

Fueron estudiadas en forma comparativa 6 cepas de P. brasiliensis con el propósito de determinar su patogenicidad para la rata y su antigenicidad. Las mismas fueron aisladas de : 1) biopsia de cuello uterino en 1989 (U), 2) biopsia de mucosa bucal en 1988 (V), 3) aspiración ósea en 1991 (63265), 4) testículo de cobayo 1984(C24), 5) punción-aspiración ganglionaren 1986 (G) y 6) cepa proveniente de la Escola Paulista de Medicina (339). Se prepararon antigenos citoplasmáticos liofilizados de cada una de ellas, en la concentración final de 100 mg/ml y se realizaron pruebas de inmunodifusión frente a 6 sueros patrones positivos de ratas. En este ensayo todos los antígenos presentaron dos ó tres bandas de precipitación. Para estudiar el poder patógeno se inocularon, en total, 120 ratas Wistar, de ambos sexos de 200 g de peso, por via intracardíaca con suspensiones de la fase levaduriforme del P. brasiliensis, en concentraciones de 3x10(7) y 5x10(7) células/ml de cada cepa. Los animales que no murieron espontáneamente fueron sacrificados a los 14,28,42, 56 y 70 dias post-infección y se evaluaron los siguientes parámetros: A) exámenes macro y microscópicos de pulmones, hígado, bazo y riñones; B) cultivos de un pulmón y C) prueba de inmunodifusión con antígeno homólogo. Se consideró además, el porcentaje de muertes espontáneas por cada cepa. Los resultados de estos estudios fueron los siguientes:No se observó relación entre la patogenicidad y la antigenicidad. La cepa más virulenta correspondió a un aislamiento reciente a partir de una forma juvenil grave y la más antigénica fue una cepa, morfológicamente atípica, que no provocó lesiones macroscópicas ni microscópicas en los órganos de las ratas.

Paracoccidioidomycosis: an update

This review summarizes knowledge on various aspects of paracoccidioidomycosis. Mycelial propagules, chlamydospores, and arthroconidia exhibit thermal dimorphism; arthroconidia are infectious in animals and, by electron microscopy, appear well provided for survival. The mycelial-to-yeast-phase transformation requires a strict control of glucan synthesis probably mediated by membrane enzymes. Hormonal influences on the transformation of the fungus (mycelium or conidium to yeast phase) have been demonstrated. Estrogen-binding proteins have been detected in the fungal cytosol, and during the transformation novel proteins are produced as a result of estradiol incorporation. Clinical forms have been better defined on the basis of better experimental models. Emphasis has been placed on the lungs as the portal of entry and on the existence of silent pulmonary infections. A specific Paracoccidioides brasiliensis antigen, the 43-kDa glycoprotein (Gp43), has been identified, characterized, and cloned. This has led to improved reproducibility and specificity of serologic tests. The depression of cell-mediated immune responses has been associated with severe disease in humans and in the experimental host. T-cell subsets in patients' tissues were characterized by means of monoclonal antibodies, and a reduced CD4/CD8 ratio was demonstrated. This has been related to alterations in lymphokine and tumor necrosis factor production, production of antigen-antibody complexes, etc. Amphotericin B has provided effective therapy. Azole derivatives have also improved prognosis and facilitated therapy. Itraconazole is presently the drug of choice, yet incapacitating sequelae (mainly pulmonary fibrosis) still constitute major problems.

Adrenocortical dysfunction in paracoccidioidomycosis: comparison between plasma beta-lipotrophin/adrenocorticotrophin levels and adrenocortical tests

OBJECTIVE

Paracoccidioidomycosis is an important cause of Addison's disease in South America. We have carried out an extensive and prospective study on paracoccidioidomycosis comparing glucocorticoid, mineralocorticoid and androgen function with adrenal regulators, ACTH/beta-LPH and plasma renin activity (PRA).

PATIENTS AND METHODS

Forty-seven male patients with active paracoccidioidomycosis were studied consecutively together with 20 healthy controls. On day 1, plasma aldosterone and PRA levels were measured in blood samples obtained from patients in the supine and erect position. On day 2 at 0900 h, baseline plasma samples were taken for ACTH, beta-lipotrophin (beta-LPH), cortisol, corticosterone, aldosterone, androstenedione (delta 4-A) and dehydroepiandrosterone sulphate (DHEA-S). ACTH 1-24 (250 micrograms) was given i.v. and blood samples for these steroid assays were taken at 1 and 2 hours.

RESULTS

Five patients (10%) had Addison's disease with high basal plasma ACTH and beta-LPH, and low cortisol levels after the ACTH test. In the remaining 42 patients, baseline ACTH and beta-LPH levels and plasma cortisol after ACTH were within the normal range. A high percentage of patients presented with reduced corticosterone (21% of patients) and aldosterone (23%) secretion and increased PRA (31%). Plasma delta 4-A (19%) and DHEA-S (50%) levels were also reduced.

CONCLUSIONS

The frequency of Addison's disease among our patients with paracoccidioidomycosis was 10%. In addition, a subset of patients presented with adrenal dysfunction detected by mineralocorticoid or androgen tests. In parallel to pathological lesions a functional adaptation may occur during adrenal involvement in paracoccidioidomycosis.

Comprometimento da medula óssea e eosinofilia na paracoccidioidomicose

São descritos 3 casos de paracoccidioidomicose com a forma aguda da doença, nos quais formas leveduriformes de Paracoccidioides brasiliensis foram visualizadas ao exame direto de medula óssea, sendo a cultura também positiva em um caso. Salienta-se o acometimento do sistema fagocítico-mononuclear e a ausência de resposta às provas cutâneas de hipersensibilidade tardia a antígenos microbianos e de P. brasiliensis em todos, bem como a gravidade do quadro clínico e lesões ósseas generalizadas em um caso, com 20.260 eosinófilos/mm³ no sangue periférico. Os autores discutem o possível papel do eosinófilo na interação hospedeiro-parasita na paracoccidioidomicose, sugerindo que a ativação de subpopulação TH 2 e o aumento de secreção de IL 5 e de GM-CSF possam estar relacionados à grande eosinofilia presente no caso mais grave

Paracoccidioidomycosis in a patient with acquired immunodeficiency syndrome

The authors report a case of paracoccidioidomycosis and other opportunistic diseases in a patient with acquired immunodeficiency syndrome.

Inapparent lung involvement in patients with the subacute juvenile type of paracoccidioidomycosis

Three patients with the diagnosis of subacute juvenile paracoccidioidomycosis who, at the time of their first visit, had no signs or symptoms of lung involvement were studied. Initially the diagnosis was confirmed by the observation of P. brasiliensis in biopsy material obtained from clinically involved lymphadenopathies. The lung X-rays done in all patients, did not reveal pathologic changes, although it was possible to observe and isolate the fungus from sputum samples obtained from the three patients. This fact reinforces the pulmonary genesis of the mycosis and proofs the existence of a pulmonary primary infection, even in patients with the juvenile manifestations, in whom the lung component is obscured by the predominant lymph node involvement.

Induction of antigen-specific T suppressor cells by soluble Paracoccidioides brasiliensis antigen

In naturally acquired paracoccidioidomycosis, patients have depressed in vivo and in vitro cell-mediated immune (CMI) responses to Paracoccidioides brasiliensis antigen. In addition, it has been reported that these patients have significant levels of circulating paracoccidioidal antigen in their sera. The primary purpose of this investigation was to assess the effects of P. brasiliensis antigen on the CMI responses in a mouse model. On the basis of findings with other fungal agents, we predicted that circulating paracoccidioidal antigen may be inducing suppressor cells which modulate the CMI response. In this study, we show (i) that a soluble P. brasiliensis culture filtrate antigen (Pb.Ag) emulsified in complete Freund adjuvant and injected subcutaneously into mice induces reasonably high levels of delayed-type hypersensitivity (DTH) in CBA/J mice; (ii) that Pb.Ag elicits DTH reactions specific for P. brasiliensis when injected into footpads of immunized mice; and (iii) that an intravenous injection of Pb.Ag induces a population of lymph node and spleen cells which, upon adoptive transfer, suppress the afferent limb of the DTH response to paracoccidioidal antigen. The afferent suppressor cells can be detected in spleens as early as 5 days after Pb.Ag treatment, are present in significant numbers by 7 days in both spleens and lymph nodes, and are virtually absent by 14 days. In contrast, at 14 days after antigen injection, efferent suppressor cells were detected in spleens and lymph nodes. The Pb.Ag-induced afferent suppressor cells specifically inhibit the antiparacoccidioidal DTH response. They are nylon wool-nonadherent cells, and their activity is abrogated by anti-Thy-1 and complement treatment, indicating that they are T lymphocytes. The phenotype of these afferent suppressor T cells is L3T4+ Lyt-1+2- I-J+. The Pb.Ag-specific suppressor cells described in this paper are similar to the Ts1 cells in the azobenzenearsonate, 4-hydroxy-3-nitrophenyl acetyl, and cryptococcal models of suppression of the DTH response and to the afferent suppressor cells in the dinitrofluorobenzene contact sensitivity system.

Paracoccidioidin sensitization in Guyana--a preliminary skin test survey in hospitalized patients and laboratory workers

Thirty-one percent of a group of 49 hospitalized patients or laboratory workers in Guyana showed positive intradermal paracoccidioidin tests in the presence of negative histoplasmin reactions. In 2 patients (4%), the intradermal reactions to paracoccidioidin were greater than 10 mm in diameter. The prevalence of positive reactors in a selected population suggests that paracoccidioidomycosis may be endemic in Guyana although no clinical case has been reported from the country. A further survey in a larger, unselected population would lead to a clearer understanding of the problem.

Adrenal function in paracoccidioidomycosis: a prospective study in patients before and after ketoconazole therapy

The adrenal gland functional reserve was studied in a group of 22 patients with active paracoccidioidomycosis before therapy and in 18 of the same patients after termination of six months of ketoconazole treatment. 22 control subjects were also tested. Serum cortisol was measured before and after i.v. infusion of 250 micrograms of corticotropin given over a period of two hours. Basal cortisol levels were subnormal in only one patients before treatment and in four of 18 patients after therapy. Overt Addison's disease was found in 14% of the patients before treatment. However, corticotropin stimulation revealed diminished adrenal reserve in 23% of patients before, and in 44% of the patients after treatment. Although decreased adrenal cortex function after therapy may be influenced by ketoconazole, more studies are needed to determine the role of this agent after prolonged use. The high frequency of subclinical adrenal failure in paracoccidioidomycosis should alert clinicians in charge of such patients, should they face physiological stress.

Multiple paracoccidioidomas simulating Wegener's granulomatosis

Five cases of paracoccidioidomas are reviewed. One case with multiple coin-lesions simulating Wegener's granulomatosis is described.

Paracoccidioidomycosis: a comparative study of the evolutionary serologic, clinical and radiologic results for patients treated with ketoconazole or amphotericin B plus sulfonamides

A comparative study of two groups of patients with paracoccidioidomycosis was carried out with the objective of comparing the evolutionary serologic, clinical and radiologic results after 6, 12, 15 and 18 months of treatment with ketoconazole (22 patients) or amphotericin B plus sulfonamides (32 patients). The serologic data analyzed as a whole showed a tendency to sharper drops in antibody titers in the patients treated with ketoconazole. Clinically patients treated with ketoconazole fared better but the differences were not statistically significant. No statistical difference was detected between groups in terms of the results of radiologic evolution.

Correlation between cell-mediated immunity and clinical forms of paracoccidioidomycosis

Cellular immune response to specific and non-specific stimulants was investigated, both in vivo and in vitro, in 29 healthy controls and in 53 previously untreated patients with the chronic isolated organic form (CIOF), the chronic mixed form (CMF) and the acute progressive form (APF) of paracoccidioidomycosis. The study included skin tests to Paracoccidioides brasiliensis antigen (PbAg) and phytohaemagglutinin (PHA), DNCB sensitization, determination of T lymphocytes and complement rosette-forming cells, lymphocyte transformation and leucocyte migration inhibition tests using PbAg and PHA. Patients displayed staggered cutaneous response to PHA and to PbAg, with marked decrease in intensity in the APF group. DNCB sensitization test and proliferative response of lymphocytes to PHA and PbAg were severely depressed in most of the patients. Leucocyte migration inhibition indices to PbAg were highly positive, while response to PHA was slightly decreased regardless of the clinical form. The number of T lymphocytes was reduced in most of patients and in them the number of complement-rosette forming cells was normal. The distribution of patients according to a suppression index, based in the results of the tests employed, revealed a tendency towards an increased degree of cellular immunosuppression from the least severe (CIOF) to the most severe (APF) clinical form of the disease. On the whole, the present study demonstrated a gamut of immunological reactivity in paracoccidioidomycosis.

Spontaneous regression of pulmonary paracoccidioidomycosis. Report of a case

A case of pulmonary paracoccidioidomycosis with spontaneous regression of the roentgenologic lesions, is reported. Regression of lesions took place within ten weeks, with the original infiltrates being replaced by fibrotic lines. The implication of this finding in the pathogenesis of paracoccidioidomycosis is analyzed.

Paracoccidioidomicose pulmonar assintomática e regressiva, com posterior disseminação: relato de um caso

É relatado o caso de um homem aparentemente sadio no qual uma abreugrafia de rotina evidenciou lesões pulmonares. Enquanto se buscava a etiologia, as lesões radiológicas foram regredindo espontaneamente até restar apenas fibrose. Por apresentar linhas de precipitação específicas frente à paracoccidioidina na prova de imunodifusão dupla em gel de agar, o paciente foi revisto 3 meses após. Nesta ocasião, persistindo a positividaàe da sorologia e a radiografia de tórax normal, surgiu uma lesão labial, na qual, ao exame microscópico, foi possível demonstrar a presença do Paracoccidioides brasiliensis. Os autores ressaltam as dificuldades diagnosticas do caso e o correlacionam com as formas clinicas da doença.

Granuloma formation and killing functions of granuloma in congenitally athymic nude mice infected with Blastomyces dermatitidis and Paracoccidioides brasiliensis

We did this experiment to clarify the mechanism of granuloma formation and the killing functions of granuloma in nude mice against Blastomyces dermatitidis and Paracoccidioides brasiliensis infections. B. dermatitidis A-295 and P. brasiliensis B-1183 were the cultures used. Congenitally athymic nude (nu/nu) mice and their heterozygous (nu/+) littermates of BALB/c background were the test animals. From culture A-295, 0.1% and 1% cell suspensions (wet weight) were prepared and from culture B-1183 0.2% and 2% cells suspensions were prepared. Ten nu/+ and 10 nu/nu mice were allotted to each of four cell suspensions. For experimental blastomycosis each mouse was inoculated intravenously with 0.2 ml of the cell suspension of A-295 and for experimental paracoccidioidomycosis, with 0.15 ml of the cell suspension of B-1183. Two mice from each of the four groups were killed at 5, 8, 12, 18 and 25 days after inoculation, and histopathologic sections, stained with H&E or by PAS, were prepared from various internal organs. In the nu/nu mice inoculated with B. dermatitidis A-295 granuloma was formed in the brain tissue after the 12th day. However, mononuclear cells, which formed the granuloma, did not kill the fungal cells, and the fungal cells continued to multiply in the granuloma. On the other hand, in the heart, kidney and fat tissue, their histopathological findings after the 18th day were clumps of fungal cells with slight cell reactions. In these organs the exertion of cell-mediated immunity was necessary for granuloma formation against the fungal infection. In the nu/nu mice infected with P. brasiliensis B-1183, granuloma appeared in the brain and kidney after the 18th day and fungal cells continued to multiply within the granuloma as well as in those inoculated with culture A-295. These results show that the exertion of cell-mediated immunity plays an important role in the mouse's defense mechanisms against these fungal infections. We assume that the defense mechanisms of immunocompetent mice against B. dermatitidis or P. brasiliensis infection consist chiefly of two steps: in the first step phagocytosis by PMNs occurs and in the second step cell-mediated immunity enters into play.

Experimental paracoccidioidomycosis in immunosuppressed mice

Mice were immunosuppressed by means of wholebody irradiation or cyclophosphamide, in order to investigate the influence on the initial phase of infection induced by a strain of the fungus, Paracoccidioides brasiliensis, in the yeast phase and inoculated intraperitoneally. A group of mice was irradiated with 600 rad (cobalt gamma-irradiation) 24 h before infection. Two groups were treated with cyclophosphamide (200 mg/kg intravenously), one two days before, and the other, one day after infection. A control group received the fungus, but no radiation or cyclophosphamide. All animals developed lesions at the site of inoculation. Metastatic lesions were observed in 100% of the animals in the irradiated group, 67% in each of the cyclophosphamide-treated groups and 33% in the control group. These lesions were found both in the liver and lungs, being more numerous in the irradiated group, followed by the cyclophosphamide-treated group in which the drug was given after the infection; they were slight in both viscera in the other cyclophosphamide-treated group and also slight in the liver and absent in the lungs of the controls.

Synergistic interaction of trimethoprim and sulfamethoxazole on Paracoccidioides brasiliensis

The in vitro interaction of trimethoprim and sulfamethoxazole on clinical isolates of Paracoccidioides brasiliensis was studied. With complete inhibition and a visual endpoint used as the criteria, three of four strains had minimal inhibitory concentrations that indicated resistance to sulfamethoxazole, and all four strains were resistant to trimethoprim. A marked synergism in inhibition was noted with the combination of these drugs against sulfa-resistant strains. A sulfamethoxazole/trimethoprim ratio of 5:1 was the most synergistic. Fifty percent inhibition, determined spectrophotometrically, of the strains could be achieved with sulfamethoxazole alone. In summary, the striking synergy observed suggests that combination chemotherapy with these drugs deserves further study.

Maturity as a critical determinant of resistance to fungal infections: studies in murine blastomycosis

Marked resistance of 9-week-old mice as compared to that of 5-week-old mice was demonstrated after pulmonary challenge with three strains of Blastomyces dermatitidis of various virulences. Quantitative studies with graded doses of the strain that was intermediate in virulence indicated that the difference in resistance between the two age groups was 1,000-fold. Acquisition of resistance appeared to be gradual between the ages of 5 and 9 weeks. Maturational differences among individual mice appeared to be most crucial at 5 weeks of age. With two fungal strains, susceptibility of the younger mice was also demonstrated after intraperitoneal challenge; with one of these strains, the differences between the two groups of mice were much smaller, suggesting that maturation of defenses in the peritoneal cavity may develop faster. Studies with serial sacrifice of different groups of mice given pulmonary challenges (of comparable amounts) indicated that the differences are not due to the amount of challenge reaching the lungs or its clearance. The infection-limiting effect in the lungs of older mice occurred within 4 days after challenge. These differences in resistance over this narrow age interval appear to be unique; resistance appears to occur later than resistance to other infectious agents and at a time when most murine immune functions have matured. This model and these observations provide an opportunity for further studies of the mechanism of resistance and are relevant to clinical observations of susceptibility of infants and children to deep mycoses.

Experimental pulmonary paracoccidioidomycosis in mice: morphology and correlation of lesions with humoral and cellular immune response

The present paper describes a murine model for pulmonary paracoccidioidomycosis injecting 6 X 10(5) yeast forms of Paracoccidioides brasiliensis (Pb) by the direct intratracheal route. The sequential histopathology of lung and dissemination lesions together with humoral (immunodiffusion test) and cellular immune response (footpad test and macrophage inhibition factor assay - MIF assay) were investigated since the 1st to the 360th day after infection. All infected animal showed pulmonary Pbmycosis up to Day 30; onwards the lesions subsided being found only in one mouse at Day 360. Dissemination lesions were observed in paratracheal and cervical lymph nodes in 9 out of 68 infected animals. Histologically early lesions were rich in polymorphonuclear cells and evolved to a macrophage desquamative pneumonitis at Day 15 and to typical epithelioid granulomata from Day 30 up to Day 360. Specific precipitating antibodies were first detected 15 days after infection, peaked from Day 30 to 60 and were not observed at Day 360. Significant cell-mediated immunity to Pb was noted at Day 15 with the peak reaction at Day 60 and 90. The intratracheal route represents a highly effective way of infecting mouse with Pb. This experimental pulmonary Pbmycosis is a granulomatous inflammation which courses with specific humoral and cellular immune response. It may be a good tool for further investigation in the pathogenesis and natural history of the disease.

The gamut of progressive pulmonary paracoccidioidomycosis

Paracoccidioidomycosis is an important Latin American endemy. The lung is the portal of entrance of the infection and the lesions are confined to this organ in, at least, 30 per cent of the progressive cases. Twelve case histories of patients with the progressive pulmonary form are presented in order to illustrate the repetitious clinical manifestations but the large variety of radiological presentations. The mycologic diagnosis is also emphasized.