Diagnosis and management of histoplasmosis

Granulomatous Hepatitis Secondary to Histoplasmosis in an Immunocompetent Patient

Histoplasma capsulatum is the most common endemic mycosis in the United States and usually occurs in certain geographic areas, such as the Mississippi or Ohio River valleys. Histoplasmosis usually causes a mild disease in the immunocompetent but can progress to disseminated disease in patients with impaired immunity. Granulomatous hepatitis as a manifestation of disseminated histoplasmosis in immunocompetent patients is extremely rare. We report the case of a 62-year-old immunocompetent gentleman with a history of histoplasmosis who presented with abdominal pain, elevated liver enzymes, who was diagnosed with granulomatous hepatitis secondary to histoplasmosis.

HIV-Associated Disseminated Histoplasmosis and Rare Adrenal Involvement: Evidence of Absence or Absence of Evidence

Adrenal histoplasmosis and primary adrenal insufficiency are mostly described in immunocompetent patients. This particular tropism is attributed to the presence of cortisol within the adrenal gland, a privileged niche for Histoplasma growth. In French Guiana, disseminated histoplasmosis is the main opportunistic infection in HIV patients. Our objective was to search in our HIV-histoplasmosis cohorts to determine how frequent adrenal insufficiency was among these patients. Between January 1, 1981 and October 1, 2014, a multicentric retrospective, observational study of histoplasmosis was conducted. Patients co-infected by HIV and histoplasmosis were enrolled in French Guiana’s histoplasmosis and HIV database. Among 349 cases of disseminated histoplasmosis between 1981 and 2014, only 3 had adrenal insufficiency (0.85%). Their respective CD4 counts were 10, 14 and 43 per mm3. All patients had regular electrolyte measurements and 234/349 (67%) had abdominal ultrasonography and 98/349 (28%) had abdominopelvic CT scans. None of these explorations reported adrenal enlargement. Overall, these numbers are far from the 10% reports among living patients and 80-90% among histoplasmosis autopsy series. This suggests 2 conflicting hypotheses: First, apart from acute adrenal failure with high potassium and low sodium, less advanced functional deficiencies, which require specific explorations, may have remained undiagnosed. The second hypothesis is that immunosuppression leads to different tissular responses that are less likely to incapacitate the adrenal function. Furthermore, given the general immunosuppression, the adrenal glands no longer represent a particular niche for Histoplasma proliferation.

Achievement of long-term remission of disseminated histoplasmosis in an AIDS patient

Histoplasmosis, a fungal infection caused by Histoplasma capsulatum, is poor prognosis once it disseminated, especially in immunocompromised patients. A 50-year-old Japanese-Brazilian male with multiple cervical lymphadenopathies was diagnosed as disseminated histoplasmosis and acquired immunodeficiency syndrome (AIDS). Anti-fungal therapy was initiated followed by anti-retroviral therapy (ART). He achieved long-term remission by treatment with voriconazole. Here we report a case of an AIDS patient with disseminated histoplasmosis who achieved long-term survival in non-endemic area.

An Italian Case of Disseminated Histoplasmosis Associated with HIV

Histoplasma capsulatum is a dimorphic fungus, endemic in the Americas, Africa (var. duboisii), India, and Southeast Asia. H. capsulatum infection is rarely diagnosed in Italy, while in Latin America, progressive disseminated histoplasmosis (PDH) is one of the most frequent AIDS-defining illnesses and causes of AIDS-related deaths. We report a case of PDH and new HIV infection diagnosis in a Cuban patient, who has been living in Italy for the past 10 years. Bone marrow aspirate and peripheral blood smear microscopy suggested H. capsulatum infection. The diagnosis was confirmed with the culture method identifying its thermal dimorphism. Liposomal amphotericin B was administered alone for 10 days and then for another 2 days, accompanied with voriconazole; the former was stopped for probable side effects (persistent fever and worsening thrombocytopenia), and voriconazole was continued to complete 4 weeks. PDH maintenance treatment consisted of itraconazole for one year. Antiretroviral therapy (ART) was started on the third week of antifungal treatment. At the 3-year follow-up, the patient is adherent on ART, the virus was suppressed, and she has an optimal immune recovery. This case highlights the need to suspect histoplasmosis in the differential diagnosis of opportunistic infections in immunocompromised persons, native to or who have traveled to endemic countries.

Pediatric Histoplasmosis in an Area of Endemicity: A Contemporary Analysis

BACKGROUND

Data on pediatric histoplasmosis have been limited to those from outbreak and case reports. We sought to evaluate the contemporary clinical manifestations, laboratory findings, and outcomes in children with histoplasmosis living in an area of endemicity.

METHODS

This study was a single-center retrospective review of proven and probable cases of histoplasmosis in children aged 0 to 18 years between April 2008 and April 2014. Case ascertainment was ensured by us using International Classification of Diseases, Ninth Revision codes cross-referenced with laboratory, microbiology, and histopathology tests that detected Histoplasma capsulatum. Demographics, diagnostics, clinical management, and outcomes were evaluated.

RESULTS

Seventy-three children with histoplasmosis (41 males; median age, 13 years [range, 3-18 years]) were diagnosed with proven (n = 17 [23%]) or probable (n = 56 [77%]) histoplasmosis, which manifested as pulmonary (n = 52 [71%]) or disseminated (n = 21 [29%]) disease. Symptoms at presentation were nonspecific; the examination of 21 (29%) patients revealed abnormal physical findings. Detection of H capsulatum by serologic methods occurred in 93% (63 of 68) of the patients tested. Histoplasma antigen in blood or urine was detected in 42% (20 of 48) and 28% (15 of 53) of the patients tested, respectively. The 16 (22%) patients who were immunocompromised had significantly higher rates of disseminated disease (56% vs 21%, respectively; P = .01), antigenuria (62% vs 18%, respectively; P = .004), and antigenemia (69% vs 31%, respectively; P = .02) and longer durations of antigenuria (403 vs 120 days, respectively; P = .003) and antigenemia (451 vs 149 days, respectively; P < .0001) than did the immunocompetent children.

CONCLUSIONS

Pediatric histoplasmosis manifests most frequently as pulmonary disease. The highest diagnostic yield was achieved when multiple diagnostic modalities were used. Presentation with disseminated disease and evidence of antigenemia, antigenuria, and delayed antigen clearance were more likely to be seen in immunocompromised children.

Progressive disseminated histoplasmosis: a systematic review on the performance of non-culture-based diagnostic tests

The diagnosis of progressive disseminated histoplasmosis is often a challenge to clinicians, especially due to the low sensitivity and long turnaround time of the classic diagnostic methods. In recent years, studies involving a variety of non-culture-based diagnostic tests have been published in the literature. We performed a systematic review by selecting studies evaluating non-culture-based diagnostic methods for progressive disseminated histoplasmosis. We searched for articles evaluating detection of antibody, antigens, as well as DNA-based diagnostic methods. A comprehensive PUBMED, Web of Science, and Cochrane Library search was performed between the years 1956 and 2016. Case reports, review articles, non-human models and series involving less than 10 patients were excluded. We found 278 articles and after initial review 18 articles were included: (12) involved antigen detection methods, (4) molecular methods, and (2) antibody detection methods. Here we demonstrate that the pursuit of new technologies is ultimately required for the early and accurate diagnosis of disseminated histoplasmosis. In particular, urinary antigen detection was the most accurate tool when compared with other diagnostic techniques.

Disseminated histoplasmosis and AIDS: a prospective and multicentre study to evaluate the performance of different diagnostic tests

The burden of histoplasmosis has been poorly documented in most of the endemic areas for the disease, including Brazil. Also, modern non-culture-based diagnostic tests are often non-available in these regions. This was a prospective cohort study in HIV-infected patients with suspected disseminated disease evaluated with different diagnostic tests. Patients were enrolled in three referral medical centres in Porto Alegre, Brazil. Among 78 evaluated patients, disseminated histoplasmosis was confirmed in eight individuals (10.3%) by the means of classical (culture/histopathology) tests. Antigen detection in the urine was found to be more sensitive: IMMY^® ALPHA ELISA detected 13 positive cases (16.7%) and the in-house ELISA test developed by the Centers for Disease Prevention and Control (CDC) detected 14 (17.9%). IMMY^® and CDC tests provided concordant results in 96.2% of cases. This is the first study to compare the performance of the in-house CDC ELISA test with the IMMY^® commercial test for the diagnosis of histoplasmosis, and a high degree of concordance was observed. The study revealed that H. capsulatum is an important agent of disseminated disease in AIDS patients in Brazil, reinforcing the importance of making available modern diagnostic tests as well as safer antifungal agents for the treatment of histoplasmosis.

Pulmonary Histoplasmosis in a Japanese Man Infected During Travel to Mexico and Management of His Wife's Condition: A Case Report

We report herein on the case of a 33-year-old Japanese man in whom an abnormal shadow was detected on chest radiography during a medical checkup after a 1-year-stay in Mexico. Chest computed tomography showed a nodule in the left lower lobe adjacent to the visceral pleura. Histopathologic examination of a thoracoscopic partial pulmonary resection specimen showed coagulation necrosis with a number of yeast-like forms on Grocott staining. In addition, serum anti-Histoplasma antibody positivity was detected with an enzyme-linked immunosorbent assay, and Histoplasma-specific nested real-time polymerase chain reaction results were positive in the pulmonary region. Finally, pulmonary histoplasmosis was diagnosed, and treatment with itraconazole was initiated. The patient's wife who had accompanied him to Mexico was asymptomatic and was not found to have histoplasmosis based on diagnostic imaging and serological findings. Although rare in Japan, histoplasmosis should be considered in the differential diagnosis of pulmonary lesions in patients who have returned from travel to endemic areas.

Quantity and Quality of Inhaled Dose Predicts Immunopathology in Tuberculosis

Experimental animal models of tuberculosis (TB) have convincingly demonstrated that inhaled dose predicts immunopathology and survival. In contrast, the importance of inhaled dose has generally not been appreciated in TB epidemiology, clinical science, or the practice of TB control. Infectiousness of TB patients has traditionally been assessed using microscopy for acid-fast bacilli in the sputum, which should be considered only a risk factor. We have recently demonstrated that cough aerosol cultures from index cases with pulmonary TB are the best predictors of new infection among household contacts. We suggest that cough aerosols of M. tuberculosis are the best surrogates of inhaled dose, and we hypothesize that the quantity of cough aerosols is associated with TB infection versus disease. Although several factors affect the quality of infectious aerosols, we propose that the particle size distribution of cough aerosols is an important predictor of primary upper airway disease and cervical lymphadenitis and of immune responses in exposed hosts. We hypothesize that large droplet aerosols (>5 μ) containing M. tuberculosis deposit in the upper airway and can induce immune responses without establishing infection. We suggest that this may partially explain the large proportion of humans who never develop TB disease in spite of having immunological evidence of M. tuberculosis infection (e.g., positive tuberculin skin test or interferon gamma release assay). If these hypotheses are proven true, they would alter the current paradigm of latent TB infection and reactivation, further demonstrating the need for better biomarkers or methods of assessing TB infection and the risk of developing disease.

SEPTIC SHOCK IN PATIENT WITH DISSEMINATED HISTOPLASMOSIS ASSOCIATED WITH AIDS: A CASE REPORT

SUMMARY Histoplasmosis is a systemic mycosis caused by Histoplasma capsulatum, which may present itself as a serious infection in immunocompromised individuals. We present a case of 31-year-old female with newly diagnosed HIV infection and history of fever, general and respiratory symptoms and diffuse hyperchromic papules through the body. She was admitted, with rapid progression to septic shock, and the presence of neutrophils filled with yeast-like organisms was detected on peripheral blood smear hematoscopia on the third day of hospitalization. The following is a brief review on the clinical picture and management of histoplasmosis.

Oropharyngeal histoplasmosis: report of eleven cases and review of the literature

INTRODUCTION: Histoplasmosis is a systemic mycosis endemic in Brazil, especially in the State of Rio Grande do Sul, where Histoplasma capsulatum was isolated from the soil. H. capsulatum may compromise unusual areas, including the oropharynx, particularly in patients presenting disseminated histoplasmosis; which is associated with a state of immunosuppression, such as AIDS. METHODS: During database analysis of a total of 265 cases of histoplasmosis, the medical records of 11 patients with histological or microbiological diagnoses of oral histoplasmosis (OH) between 1987 and 2008 were retrospectively reviewed. RESULTS: This work reports 11 cases of OH, the majority presenting histopathological or microbiological evidence of disseminated histoplasmosis (DH). In the patients with DH, OH was the first manifestation of histoplasmosis. Five of the 11 patients discussed were HIV-seropositive with clinical and laboratory findings of AIDS. Four patients presented active pulmonary tuberculosis concomitant with histoplasmosis. Treatment was based on the use of itraconazole and amphotericin B deoxycholate. Eight patients responded successfully to therapy after one year, two did not come back for reevaluation and one died despite adequate therapy. CONCLUSIONS: Oral histoplasmosis is closely associated with immunosuppression status, especially in patients presenting AIDS; moreover, in many cases, OH is the first sign of disseminated histoplasmosis.

Histoplasmose

A histoplasmose é uma micose causada por fungo dimórfico, o Histoplasma capsulatum. É considerada classicamente uma micose endêmica, embora o fungo tenha um comportamento oportunístico em pacientes com depressão da imunidade celular. O homem adquire a infecção através da inalação de conídeos presentes na natureza (cavernas com morcegos, galinheiros, etc). O quadro clínico pode variar, desde infecções assintomáticas até quadros graves disseminados, que acometem pacientes com Aids, transplantados ou com neoplasias hematológicas. O diagnóstico baseia-se no encontro do fungo em fluidos orgânicos (escarro, sangue, líquor) ou tecidos (histopatologia), na cultura de materiais biológicos e na sorologia. O tratamento das formas agudas graves, respiratória crônica ou de formas localizadas pode ser feito com azólicos orais (itraconazol) e nas disseminadas, a Anfotericina B (preferencialmente as formulações lipídicas) constitui a droga da eleição para iniciar a terapia. A histoplasmose representa, hoje uma das micoses sistêmicas mais importantes nas Américas, com ampla distribuição em todas as regiões do Brasil.

Chest Pain Resulting From Histoplasmosis Pericarditis

Histoplasmosis is an endemic disease in many regions of the United States. Physicians must be aware of the clinical syndromes and take advantage of epidemiologic clues when diagnosing histoplasmosis pericarditis. Clinicians must also be familiar with the uses and limitations of a battery of serologic and mycologic tests. Finally, further clinical trials are needed to study the role of antifungal therapy in the treatment of histoplasmosis pericarditis.

Histoplasmosis infection in Spanish travelers to Latin America

The aim of the study presented here was to assess the incidence of histoplasma infection in a cohort of 342 individuals in Spain who had traveled to Latin America for the first time. The histoplasmin skin test was positive in 20% of the travelers, and Central America posed a higher risk for infection than South America (p=0.013). Sleeping outdoors (p=0.031) and the duration of travel (p=0.016) were also identified as significant risk factors. Serological testing demonstrated poor overall sensitivity for detecting infection in the travelers, but for the symptomatic acute cases the results were improved. Histoplasmosis must be considered in patients presenting with fever (odds ratio=3.51 [1.52-8.12]) or cough (odds ratio=4.24 [1.32-13.58]) after visiting Latin America. The results of this study have public health implications and indicate the risks of acquiring histoplasmosis should be included in pre-travel counseling.

DIAGNOSIS OF HISTOPLASMOSIS

Endemic mycoses can be challenging to diagnose and accurate interpretation of laboratory data is important to ensure the most appropriate treatment for the patients. Although the definitive diagnosis of histoplasmosis (HP), one of the most frequent endemic mycoses in the world, is achieved by direct diagnosis performed by micro and/or macroscopic observation of Histoplasma capsulatum (H. capsulatum), serologic evidence of this fungal infection is important since the isolation of the etiologic agents is time-consuming and insensitive. A variety of immunoassays have been used to detect specific antibodies to H. capsulatum. The most applied technique for antibody detection is immunodiffusion with sensitivity between 70 to 100 % and specificity of 100%, depending on the clinical form. The complement fixation (CF) test, a methodology extensively used on the past, is less specific (60 to 90%). Detecting fungal antigens by immunoassays is valuable in immunocompromised individuals where such assays achieve positive predictive values of 96-98%. Most current tests in diagnostic laboratories still utilize unpurified antigenic complexes from either whole fungal cells or their culture filtrates. Emphasis has shifted, however, to clinical immunoassays using highly purified and well-characterized antigens including recombinant antigens. In this paper, we review the current conventional diagnostic tools, such as complement fixation and immunodiffusion, outline the development of novel diagnostic reagents and methods, and discuss their relative merits and disadvantages to the immunodiagnostic of this mycosis.

Rapid identification of dimorphic and yeast-like fungal pathogens using specific DNA probes

Specific oligonucleotide probes were developed to identify medically important fungi that display yeast-like morphology in vivo. Universal fungal primers ITS1 and ITS4, directed to the conserved regions of ribosomal DNA, were used to amplify DNA from Histoplasma capsulatum, Blastomyces dermatitidis, Coccidioides immitis, Paracoccidioides brasiliensis, Penicillium marneffei, Sporothrix schenckii, Cryptococcus neoformans, five Candida species, and Pneumocystis carinii. Specific oligonucleotide probes to identify these fungi, as well as a probe to detect all dimorphic, systemic pathogens, were developed. PCR amplicons were detected colorimetrically in an enzyme immunoassay format. The dimorphic probe hybridized with DNA from H. capsulatum, B. dermatitidis, C. immitis, P. brasiliensis, and P. marneffei but not with DNA from nondimorphic fungi. Specific probes for H. capsulatum, B. dermatitidis, C. immitis, P. brasiliensis, P. marneffei, S. schenckii, C. neoformans, and P. carinii hybridized with homologous but not heterologous DNA. Minor cross-reactivity was observed for the B. dermititidis probe used against C. immitis DNA and for the H. capsulatum probe used against Candida albicans DNA. However, the C. immitis probe did not cross-react with B. dermititidis DNA, nor did the dimorphic probe hybridize with C. albicans DNA. Therefore, these fungi could be differentiated by a process of elimination. In conclusion, probes developed to yeast-like pathogens were found to be highly specific and should prove to be useful in differentiating these organisms in the clinical setting.

Pulmonary Histoplasmosis

Most patients with pulmonary histoplasmosis experience a self-limited illness that rarely requires treatment. However, patients who inhale a large burden of organisms from the environment and those who are immunosuppressed may develop severe, life-threatening pneumonia. Chronic histoplasmosis occurs almost exclusively in patients with severe chronic obstructive pulmonary disease. Complications of pulmonary histoplasmosis are mostly related to persistent mediastinal lymphadenopathy. Mild to moderate forms of pulmonary histoplasmosis should be treated with itraconazole. Patients with severe pulmonary involvement should initially receive amphotericin B; after the patient's condition has improved, therapy can be changed to itraconazole. Preventive measures should be used to protect workers from exposure to large numbers of Histoplasma capsulatum organisms.

Imported histoplasmosis in Spain

Histoplasma capsulatum is a dimorphic fungus endemic in the American continent but not in Europe, where cases are usually imported. Its favorite habitat is in warm humid soils. Guano from birds and bats enhance the sporulation of the mycelial phase.1 Man acquires H. capsulatum through inhalation of spores. Most people infected by this fungi remain asymptomatic, but around 10-50% can start an illness ranging from acute pulmonary histoplasmosis to chronic histoplasmosis. In both, there is close clinical resemblance to pulmonary tuberculosis. Immunodepressed patients undergo a more severe form of the disease, usually presenting in the acute disseminated form. We present seven immunocompetent patients with histoplasmosis acquired after traveling to several American countries.

Central nervous system histoplasmosis mimicking a brain tumor: difficulties in diagnosis and treatment

Neurologic involvement occurs in 10% to 20% of patients with disseminated histoplasmosis. We describe a 20-year-old woman who had headache and diplopia but no evidence of systemic infection. Magnetic resonance imaging showed an enhancing mass in the thalamomesencephalic and third ventricular region. After subtotal resection of what was presumed to be a glioma, the patient had symptoms and signs of meningitis. Subsequent pathological review demonstrated noncaseating granulomas, and serologic tests and cultures confirmed the diagnosis of histoplasmosis. Initiation of antifungal therapy and removal of an infected shunt system resulted in clinical improvement. Clinicians should maintain a high index of suspicion in patients who are from any area endemic for histoplasmosis.

Molecular cloning, characterization, and expression of the M antigen of Histoplasma capsulatum

The major diagnostic antigens of Histoplasma capsulatum are the H and M antigens, pluripotent glycoproteins that elicit both humoral and T-cell-mediated immune responses. These antigens may play a role in the pathogenesis of histoplasmosis. M antigen is considered immunodominant because antibodies against it are the first precipitins to arise in acute histoplasmosis and are commonly present during all phases of infection. The biological activity of monomolecular M antigen and its ability to elicit a protective immune response to H. capsulatum are largely unknown. A molecular approach was used to identify the biological nature of M antigen, including its purification from histoplasmin, partial digestion with proteinases, and reverse-phase high-performance liquid chromatography to separate the released peptides. The amino acid sequences of the purified peptides were obtained by Edman degradation, and using degenerate oligonucleotide primers for PCR, a 321-bp fragment of the gene encoding the M antigen was amplified from genomic H. capsulatum DNA. This fragment was used to screen an H. capsulatum genomic DNA library, leading to the isolation, cloning, and sequencing of the full-length gene. The M gene consists of 2, 187-bp DNA encoding a protein of 80,719 Da, which has significant homology to catalases from Aspergillus fumigatus, Aspergillus niger, and Eimericella nidulans. A cDNA was generated by reverse transcription-PCR and cloned into the expression vector pQE40. The identity of the cloned, expressed protein was confirmed by Western blotting. The recombinant fusion protein was immunoreactive with monoclonal antibodies raised against M antigen, with polyclonal mouse anti-M antiserum, and with a serum sample from a patient with histoplasmosis. The gene encoding the major immunodominant M antigen of H. capsulatum is a presumptive catalase, and the recombinant protein retains serodiagnostic activity.

Detection of the 70-kilodalton histoplasma capsulatum antigen in serum of histoplasmosis patients: correlation between antigenemia and therapy during follow-up

Histoplasmosis is an important systemic fungal infection, particularly among immunocompromised individuals, who may develop a progressive disseminated form which is often fatal if it is untreated. In such patients, the detection of antibody responses for both diagnosis and follow-up may be of limited use, whereas the detection of Histoplasma capsulatum var. capsulatum antigens may provide a more practical approach. We have recently described an inhibition enzyme-linked immunosorbent assay (ELISA) for the detection in patients' sera of a 69- to 70-kDa H. capsulatum var. capsulatum-specific antigen which appears to be useful in diagnosis. To investigate its potential for the follow-up of histoplasmosis patients during treatment, antigen titers in the sera of 16 patients presenting with different clinical forms of histoplasmosis were monitored at regular intervals for up to 80 weeks. Sera from four of five patients with the acute form of the disease showed rapid falls in antigenemia, becoming antigen negative by week 14 (range, weeks 10 to 16). Sera from four patients with disseminated histoplasmosis showed falls in antigen levels; three of them became antigen negative by week 32; the fourth patient became negative by week 48. In contrast, antigen titers in four of six AIDS patients with the disseminated form of the disease remained positive throughout follow-up. Sera from only one patient who presented with the chronic form of the disease were analyzed, and this individual's serum became antigen negative by week 9. The inhibition ELISA is shown to be of particular use in the monitoring of non-AIDS patients with the acute and disseminated forms of the disease and may complement existing means of follow-up.

Evaluation of a western blot test in an outbreak of acute pulmonary histoplasmosis

A western blot (WB) test was evaluated for detection of antibodies against native glycosylated and chemically deglycosylated M and H antigens of Histoplasma capsulatum in serum obtained from patients during the acute phase of pulmonary histoplasmosis that occurred during an outbreak. Of 275 serum samples tested by immunodiffusion and complement fixation (CF) samples from 40 patients affected during this outbreak and from 37 negative controls were tested by WB test. A group of patients whose sera were negative for CF antibodies and precipitins early in the acute stage of histoplasmosis but who all seroconverted during convalescence 6 weeks later were tested with the WB test. Antibodies against untreated H and M antigens were detected at a 1:100 dilution by WB test in 45% of the 20 acute-phase serum samples and in all 20 of the convalescent-phase specimens. The WB test's sensitivity for acute-phase specimens increased to 90% (18 of 20 specimens) when H and M antigens were treated by periodate oxidation to inactivate susceptible carbohydrate epitopes. When native glycosylated antigens were used in the WB test, positive reactions were observed in negative control serum specimens (3 of 37 specimens; 8%) and in serum specimens obtained from asymptomatic persons screened as part of the outbreak investigation (13 of 20 specimens; 65%). These positive reactions were also attributed to glycosidic epitopes since the specificity of the WB test increased from 78 to 100% when periodate-treated H and M antigens were used. WB test with deglycosylated H and M antigens of histoplasmin provides a rapid, sensitive, and specific test to diagnose acute pulmonary histoplasmosis before precipitins can be detected.

Acute Histoplasmosis in Spelunkers Returning from Mato Grosso, Peru

Background: Histoplasmosis is a fungal disease with a worldwide distribution. Travelers returning from endemic areas with a history of exposure to fungal spores have a high risk of infection. Methods: We report four cases of acute pulmonary disease in Italian spelunkers returning from Mato Grosso, Peru. Results: Symptoms and radiologic findings were consistent with acute pulmonary illness. Laboratory data supported the hypothesis of histoplasmosis. Conclusions: Histoplasmosis should be considered in the differential diagnosis in travelers returning from endemic areas, who report a risk of exposure, and present with respiratory illness. In this setting, seroconversion may be considered diagnostic of pulmonary histoplasmosis.

Development of a novel antigen detection test for histoplasmosis

Histoplasmosis is an important systemic fungal infection, particularly among immunocompromised individuals living or travelling in areas of endemicity, who, without antifungal therapy, may develop a progressive disseminated fatal infection. For such patients, the detection of antibody responses by immunodiffusion or complement fixation test is of limited use. In contrast, the detection of Histoplasma capsulatum circulating antigens may provide a more practical approach to the rapid diagnosis of the disease. Accordingly, an inhibition enzyme-linked immunosorbent assay (ELISA) for the detection of a 69- to 70-kDa H. capsulatum-specific determinant and incorporating a species-specific murine monoclonal antibody was developed. With sera from patients with different forms of the disease (n = 35), the overall sensitivity of the test was found to be 71.4%, while the specificity was found to be 98% with normal human sera from areas of endemicity (n = 44) and 85.4% with sera from patients with other chronic fungal or bacterial infections (n = 48). This novel, highly specific ELISA provides a significant addition to the existing diagnostic tests for the detection of histoplasmosis.

Histoplasmosis. Experience during outbreaks in Indianapolis and review of the literature

Histoplasmosis remains a common infection in endemic regions of North America and Latin America, causing a broad spectrum of clinical findings. Experience during recurrent outbreaks in Indianapolis has shown the importance of immunosuppressive conditions including the acquired immunodeficiency syndrome (AIDS) as a risk factor for disseminated disease and expanded our knowledge of the common clinical manifestations. Pericarditis, rheumatologic manifestations, esophageal compression, and sarcoidlike manifestations were found to be relatively common findings in histoplasmosis. These studies have established the useful role of serologic testing and have led to the discovery of antigen testing for diagnosis of histoplasmosis. This experience also has offered the opportunity to examine the outcome of treatment in persons with AIDS, contributing to studies that have found itraconazole to be an excellent alternative to amphotericin B in persons with mild or moderately severe infection.

Massive hemoptysis as the presenting manifestation in a child with histoplasmosis

A previously healthy and asymptomatic 7-year-old white boy presented with a history of two episodes of hemoptysis productive of bright red blood in the 5 days preceding admission. After admission he developed massive hemoptysis that, on bronchoscopy, was noted to be emanating from the right lower lobe. An emergency right lower lobe resection was done. Pathological examination revealed hilar adenopathy and peripheral lesions with caseating granulomas containing yeast, morphologically consistent with Histoplasma capsulatum.

Disseminated histoplasmosis in a patient with sarcoidosis: a controversial relationship and a diagnostic dilemma

The diagnosis of sarcoidosis in patients with disseminated histoplasmosis remains controversial. It has been suggested that the immune abnormalities in sarcoidosis predispose one to disseminated histoplasmosis. Two cases have been reported that indicate a possible relationship between the two diseases. This is a case of sarcoidosis complicated with disseminated histoplasmosis in which the controversial relationship between the two diseases is emphasized and the available medical literature is reviewed.

Disseminated histoplasmosis presenting as myositis and fasciitis in a patient with dermatomyositis

A 54-year-old man with dermatomyositis initially responsive to corticosteroids and methotrexate developed severe myalgias, increasing weakness, and fevers. Laboratory studies were suggestive of disseminated histoplasmosis, and muscle biopsy revealed myositis, fasciitis, and yeast in the perimysial connective tissue. Histoplasma capsulatum was cultured from skeletal muscle. Despite antifungal therapy, necrotizing fasciitis progressed to gluteal abscess formation. Disseminated histoplasmosis may present atypically in immunocompromised hosts as fasciitis and myositis. Patients with dermatomyositis could be particularly vulnerable to soft tissue invasion by fungi due to their underlying microangiopathy.

Effects of histoplasmin M antigen chemical and enzymatic deglycosylation on cross-reactivity in the enzyme-linked immunoelectrotransfer blot method

The enzyme-linked immunoelectrotransfer blot (EITB) method was evaluated as a suitable method for detecting antibodies against M antigen of Histoplasma capsulatum by use of both glycosylated and deglycosylated M protein of histoplasmin (HMIN). Sera from patients with histoplasmosis, paracoccidioidomycosis, blastomycosis, coccidioidomycosis, and aspergillosis were tested by the EITB with glycosylated M protein of HMIN. This assay demonstrated 100% sensitivity with histoplasmosis serum samples, all of which reacted with the 94-kDa glycoprotein (M antigen). Although the EITB is highly sensitive, it is not specific for histoplasmosis when glycosylated M protein is used as an antigen. A total of 81% of paracoccidioidomycosis, 25% of blastomycosis, 33% of coccidioidomycosis, 73% of aspergillosis, and 16% of tuberculosis serum samples cross-reacted with M protein of HMIN and yielded patterns indistinguishable from those obtained with histoplasmosis serum samples. The EITB reactions with both untreated M antigen and M antigen altered by periodate oxidation or by deglycosylation with endoglycosidases were compared. Cross-reactions with heterologous sera in the EITB could be attributed to periodate-sensitive carbohydrate epitopes, as reflected by the increase in the test specificity from 46.1 to 91.2% after periodate treatment of M protein. The EITB for the detection of antibodies to M antigen is a potential diagnostic test for histoplasmosis, provided that periodate-treated M protein is used as an antigen.

Oral Histoplasma capsulatum infection in association with HIV infection: a case report

The fungus Histoplasma capsulatum causes histoplasmosis, the most common endemic respiratory mycosis in the United States. Disseminated histoplasmosis in adults is often associated with immunosuppression, such as occurs in HIV infection. We report a case of oral histoplasmosis in an HIV-seropositive patient who presented with an ulceration on the left tip of the tongue, extending to the floor of the mouth, but was otherwise free of any active systemic disease. Histoplasma capsulatum was shown, by both histopathology and staining with a fluorescent antibody reagent specific for the organism, to be present in the lesion and was deduced to be the causative organism.

[A case of AIDS-associated histoplasmosis in Germany]

In a thirty-year-old patient with AIDS the diagnosis of disseminated histoplasmosis was established via biopsy and culture. The patient had grown up in Argentina, where histoplasmosis is endemic. He had not been in an endemic region during the last two years anteceding the manifestation of systemic histoplasmosis. Accordingly, in patients with a progressive immunodeficiency syndrome, reactivation of a former (possibly inapparent) infection with Histoplasma capsulatum must be considered. Therapy with Amphotericin B lead to a remarkable improvement of clinical, laboratory and sonographic findings. Due to the fact that total eradication of H. capsulatum from the infected host cannot be achieved with any known drug regimen, a life-long follow-up therapy was begun. The patient showed no signs of relapse after a follow-up of 7 months.