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PubMed1999

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 Disease↗

PubMed1972

Pathogenesis and immunological aspects of experimental histoplasmosis in cynomolgus monkeys (Macaca fascicularis).

Studies were carried out to obtain basic information on the pathogenesis of experimental histoplasmosis in Cynomolgus monkeys (Macaca fascicularis) and to determine whether such infected primates can be used as a source of positive reference sera in serological tests for histoplasmosis. Ten monkeys were inoculated intraperitoneally with approximately 9.1 x 10(7) viable Histoplasma capsulatum yeast-form cells or cell aggregates. At periodical intervals, their sera were tested for antibodies to H. capsulatum by the complement fixation (CF), immunodiffusion, and latex agglutination tests. Selected monkeys were also sacrificed at periodical intervals for cultural and pathological evaluation of their tissues. Infection with H. capsulatum elicited high-antibody responses, and the fungus disseminated to many organs. Initially, the infected monkeys developed CF titers as high as 1:256 to both histoplasmin and H. capsulatum yeast cell antigens. Subsequent challenges boosted the CF antibody titers to levels as high as 1:1,024. All of the monkeys developed M precipitins, and some also produced H precipitins. Latex agglutination titers as high as 1:1,024 were also demonstrated. Our findings show that Cynomolgus monkeys experimentally infected with H. capsulatum by the intraperitoneal route develop a mild form of histoplasmosis and that these animals can be used as a source of reference sera in serological tests for histoplasmosis.

Animals↗

PubMed1991

Production and characterization of a monoclonal antibody to the complement fixation antigen of Coccidioides immitis.

Detection of complement-fixing antibody to coccidioidin by using the complement fixation test or an immunodiffusion assay for complement-fixing antibody (IDCF) is widely viewed as the most useful immunodiagnostic test for coccidioidomycosis. In this investigation, we report the production of an immunoglobulin G subclass 1 (IgG1) monoclonal antibody (MAb) to the IDCF antigen for use as a biospecific ligand for purifying the IDCF antigen on solid-phase immunosorbents and for use as a reagent for screening genomic or cDNA expression libraries from Coccidioides immitis. BALB/c mice were immunized by intramuscular injections of coccidioidin in adjuvant, followed by an intrasplenic booster injection of coccidioidin in saline. The spleen cells were fused with SP2/0 Ag14 myeloma cells, and the fusion products were screened for IgG antibody to coccidiodin by using an enzyme-linked immunosorbent assay. Positive hybridomas were cloned and evaluated for reactivity to the IDCF antigen by two-dimensional immunoelectrophoresis and by immunoblotting. An IgG1 Mab was produced that was specific for the IDCF antigen when evaluated by two-dimensional immunoelectrophoresis and immunoblotting. The epitope recognized by the MAb was heat labile (60 degrees C, 30 min) and susceptible to enzymatic digestion with pronase but was resistant to treatment with lipase, alpha-mannosidase, glucose oxidase, and endoglycosidase H. This heat-labile peptide epitope appears to be specific to C. immitis, as judged by the fact that the MAb was not reactive in immunoblots or enzyme-linked immunosorbent assays of histoplasmin or blastomycin.

Animals↗

PubMed1995

Immunobiological activity of recombinant H antigen from Histoplasma capsulatum.

The H antigen from Histoplasma capsulatum is one of the known principal antigens of this fungus, but information regarding its identity and its participation in cellular immunity is largely unavailable. Therefore, we sought to determine both the nature of this antigen and the nature of its involvement in the cell-mediated immune response. The antigen was isolated from histoplasmin and digested with selected proteinases, and the cleavage products were subjected to reverse-phase high-performance liquid chromatography. Amino acid sequences of protein fragments were obtained by Edman degradation. A fragment of the gene encoding the H antigen was isolated by using degenerate primers in the PCR. This fragment was used to screen a genomic library, and the full-length gene was isolated and sequenced. The deduced amino acid sequence revealed homology to extracellular beta-glucosidases. A cDNA was generated by reverse transcription PCR and cloned into the expression vector pET 19b. Recombinant H antigen was isolated from inclusion bodies of Escherichia coli and tested for its ability to elicit and induce an in vitro cell-mediated immune response in BALB/c mice. Recombinant antigen stimulated splenocytes from mice immunized with viable yeast cells or with antigen suspended in adjuvant. Mice inoculated with H antigen were not protected against either a sublethal or a lethal inoculum of yeast cells. Thus, H antigen stimulates a cell-mediated immune response but does not induce a protective response to H. capsulatum.

Amino Acid Sequence↗

PubMed1976

Specific immunological test for the rapid identification of members of the genus Histoplasma.

A sensitive and specific immunological method was developed for rapid identification of the mycelial forms of Histoplasma capsulatum var. capsulatum, H. capsulatum var. duboisii, and H. farciminosum and for separation of these pathogenic fungi from morphologically similar hyphomycetes and other fungal pathogens. This method is based on the fact that all of the Histoplasma spp. produce H and M histoplasmin antigens, whereas the other fungi do not. Inocula consisting of heavy mycelial growth from a pure, full-grown culture were transferred into flasks containing small volumes of brain heart infusion broth. These cultures were placed on a shaker and grown at 25 C. Using the micro-immunodiffusion technique and antisera containing antibodies to H and M precipitinogens, we detected exoantigens in 3-day-old brain heart infusion culture supernatants concentrated 25 and 50 times. The ability of the procedure to identify Histoplasma spp. was evaluated by testing 96 unknown mycelial cultures that grossly or microscopically resembled Histoplasma spp. Three- and six-day-old concentrated culture supernatants prepared from each unknown were tested against rabbit anti-Arthroderma tuberculatum, Chrysosporium keratinophilum, H. capsulatum var. duboisii, and Corynascus (Thielavia) sepedonium sera and human histoplasmosis case serum. Each unknown was also identified by conventional laboratory procedures involving cultural and, where necessary, in vivo studies. In the comparative evaluation the immunological test was observed to be 100% sensitive. It permitted the accurate generic identification of the Histoplasma spp. within 5 days, in contrast to the average of 33 days required by the routine mycological procedure.

Antigens, Fungal↗

PubMed1975

Acute presumed histoplasmosis of the optic nerve head.

A 38-year-old man from the Ohio Valley area presented to the Ophthalmology Cinic at a west coast hospital (USA) because of sudden loss of the right inferior temporal visual field after severe right frontal headache of several hours' duration. During the following months, diffuse peripapillary atrophy and peripheral punched-out lesions developed. When he had been seen initially, the fundus of the left eye had also revealed extensive, diffuse, peripapillary atrophy and scarring. All laboratory tests were normal except a histoplasmin intradermal skin test. The clinical appearance of both eyes 8 months after the acute episode in the right eye supports the diagnosis of presumed ocular histoplasmosis.

Acute Disease↗

PubMed2005

[Histoplasma capsulatum infection in a group of travelers to Guatemala].

OBJECTIVE: To analyze the epidemiological and clinical characteristics of Histoplasma capsulatum infection in a group of volunteers who had traveled to Guatemala. METHODS: A review was performed of the clinical records of nine patients who consulted at the Tropical Medicine Outpatient Unit of Hospital Clinic in Barcelona, Spain. RESULTS. All patients were attended for travelers' diarrhea. In addition, one student had also presented with respiratory symptoms and fever while in Guatemala and her chest X-ray showed interstitial infiltrates. The epidemiological history recognized risk factors for histoplasmosis in all patients (all of them had been working in the reconstruction of an old school building). The intradermal histoplasmin test was performed and was positive in all nine patients. None of the students required treatment. CONCLUSIONS: Histoplasmosis should be included in the differential diagnosis of returning travelers' fever. The diagnosis would have been missed in all of our patients if not for a directed clinical history taking. It is important to reinforce prevention measures, e.g. the use of face masks, when working in an environment with a risk for acquiring histoplasmosis.

Adult↗

PubMed1988

Experimental pulmonary histoplasmosis and emphysema.

Chronic pulmonary histoplasmosis often occurs in the setting of emphysema. However, it is unknown whether emphysema directly predisposes to the development of the necrotizing lesions of chronic pulmonary histoplasmosis. We evaluated this possibility using a murine model of pulmonary histoplasmosis. Using intratracheal inoculation of elastase, we induced pulmonary emphysema in Balb/c mice. When mice with emphysema were challenged intranasally with H. capsulatum (HC) yeast cells, the course of their disease was not significantly different from that of normal mice. Mice were also exposed to HC antigens by sublethal intranasal challenge with viable or heat-killed HC, or immunized with histoplasmin. Prior sublethal challenge with viable HC did not cause prolonged illness or increased mortality in the setting of emphysema. In contrast, such mice were protected against a severe rechallenge. Additional studies showed that intranasal administration of heat-killed HC or subcutaneous immunization with histoplasmal antigens had neither protective nor deleterious effects on the course of histoplasmosis. Therefore, in this murine model, we could not substantiate an interaction of underlying emphysema with acute primary or rechallenge pulmonary histoplasmosis.

Animals↗

PubMed1978

Cell-mediated immunity in anergic patients with pulmonary tuberculosis.

Twelve adults with confirmed pulmonary tuberculosis who failed to respond to repeated skin tests with 250 TU of second-strength purified protein derivative of tuberculin were studied using in vivo and in vitro tests of cell-mediated immunity. All but 2 of the patients failed to respond to skin tests with candidin and histoplasmin, and only one could be sensitized with topical applications of dinitrochlorobenzene. The blastogenic response of peripheral blood lymphocytes from these anergic patients, when cultured in the presence of phytohemagglutinin, pokeweed mitogen, and purified protein derivative, was significantly less than that of lymphocytes from tuberculin-positive control patients. During the course of therapy with isoniazid and streptomycin, 6 of the anergic patients converted spontaneously and reacted positively to purified protein derivative. This skin-test conversion was accompanied by a significant increase in the blastogenic response of lymphocytes from the converted patients when cultured with purified protein derivate. Tuberculin anergy in these 12 patients was not associated with progessive, disseminated disease. All patients responded successfully to the primary chemotherapeutic regimen.

Adolescent↗

PubMed1972

Cellular immunity to nuclear antigens in systemic lupus erythematosus.

Cellular immune repsonses were determined by skin testing and mitogen- and antigen-induced blastic transformation of peripheral blood lymphocyte cultures in 24 patients with systemic lupus erythematosus (SLE) and 24 normal subjects. The incidence of positive skin tests with Candida albicans, PPD (tuberculin-purified protein derivative) intermediate strength, Trichophyton and histoplasmin was not significantly different in the two groups nor was lymphocyte stimulation by the mitogen phytohemagglutinin-M (PHA-M), implying that cellular immunity is normal in SLE. However, the SLE patients had a significantly increased incidence of positive skin tests and stimulated lymphocyte cultures to a number of nuclear antigens compared with normal subjects. No correlation could be made between the test results and the activity of the SLE at the time of study except for a significant association between lymphocyte culture stimulation by rabbit thymus native DNA and active SLE nephritis. Patients with a membranous antinuclear factor (ANF) pattern had positive skin tests with rabbit thymus native DNA and usually had active disease.

Adolescent↗

PubMed1976

Suppressor thymus-derived lymphocytes in fungal infection.

Thymus-derived lymphocyte (T-cell) function, as determined in vivo by cutaneous reactivity to several antigens and in vitro by responsiveness to mitogens and antigens, was assessed in 14 patients infected with a variety of fungal organisms. While all patients manifested a normal frequency of peripheral blood T cells, only seven patients reacted to at least one of the antigens used for cutaneous testing and demonstrated normal in vitro T proliferative responses. Three patients exhibited cutaneous anergy but normal in vitro T-cell reactivity while four patients demonstrated persistent anergy and marked in vitro T-cell hyporeactivity which was independent of activity of infection, concurrent medication, or any associated disorders. The marked diminution of in vitro T-cell reactivity noted for these later four patients was not due to a deletion of antigen- or mitogen-reactive cells. Thus, patients' cells which had been initially cultured for 7 days without any mitogenic or antigenic stimulus and which were subsequently washed and recultured with phytohemagglutinin, concanavalin A, or histoplasmin demonstrated a marked increase in their responsiveness. Moreover, this reactivity noted for recultured cells could be suppressed by a nonphagocytic, nonadherent, nonimmunoglobulin-bearing, sheep red blood cell rosette-forming population of cells isolated from the fresh peripheral blood mononuclear cells of the same patient. While these "regulator" T cells were capable of suppressing T-proliferative responses to antigens and mitogens, they did not diminish pokeweed mitogen-induced immunoglobulin synthesis by normal bone marrow-derived lymphocytes. Patients in whom suppressor "T" cells were found were at risk for relapsing, disseminated fungal infection.

Antigen-Antibody Reactions↗

PubMed1979

Immune responses in bats following intranasal infection with Histoplasma capsulatum.

Groups of bats (Artibeus lituratus) were infected by the intranasal instillation of a suspension of mycelia and spore particles of Histoplasma capsulatum containing either 10(4) or 10(6) viable units. Bats infected with the high dose had viable H. capsulatum in the lungs, liver, spleen and gut as early as 2 weeks post-infection. Complement-fixing antibodies to the organism were detectable 3 weeks after infection, whereas precipitating antibodies were not persent until 5 weeks. Significantly delayed hypersensitivity to histoplasmin was noted at 2 and 4 weeks after infection. By 9 weeks, delayed hypersensitivity had waned, while antibodies could still be demonstrated. The observation that bats are susceptible to respiratory infection with H. capsulatum suggests a mechanism by which the disease may be maintained within a colony. Delayed hypersensitivity appears to be a sensitive, but transient, indicator of active histoplasmosis in bats.

Animals↗

PubMed1999

Outbreak of histoplasmosis among cavers attending the National Speleological Society Annual Convention, Texas, 1994.

In June 1994, 18 people developed serologically confirmed histoplasmosis following cave exploration associated with the annual National Speleological Society Convention in Bracketville, Texas. Six others had an undiagnosed illness suspected to be histoplasmosis. Two persons were hospitalized. We conducted a survey of convention attendees and a nested case-control study of those entering caves. We also conducted a histoplasmin skin test survey of a subgroup of the society, the Texas Cavers Association, who were attending a reunion in October 1994. Among the national convention attendees, exposure to two caves was identified as responsible for 22 (92%) of the 24 cases; 12 (75%) of 16 people exploring one cave (Cave A) and 10 (77%) of 13 exploring a separate cave (Cave B) developed acute histoplasmosis. Additional risk-factors included fewer years of caving experience, longer time spent in the caves, and entering a confined crawl space in Cave A. Of 113 participants in the separate skin test survey, 68 (60%) were found to be skin test positive, indicating previous exposure to Histoplasma capsulatum. A positive skin test was significantly associated with male sex and more years of caving experience. Those less experienced in caving associations should be taught about histoplasmosis, and health care providers should pursue histories of cave exposure for patients with bronchitis or pneumonia that does not respond to initial antibiotic therapy.

Adolescent↗

PubMed1999

[Paracoccidioides brasiliensis infection in a subtropical region with important environmental changes].

Paracoccidioidomycosis is a systemic mycoses caused by Paracoccidioides brasiliensis, a dimorphic fungus that infects man through respiratory ducts. It has been accepted that its ecological niche is located in the soil and plants of subtropical forests of Latin America. The Province of Corrientes is located at the northeastern border of Argentina, in a subtropical area where important environmental modifications have been introduced in the last decade as consequence of damming the Paranà river at Yacyretà, one of the biggest hydroelectric dams in the world. Since there are no data on human infection provoqued by this fungal agent in Corrientes, the purpose of this study was to obtain information at present time about infection indexes and to assess if environmental changes introduced in the area could impact on the epidemiology of the disease. Skin tests with paracoccidioidin and histoplasmin were performed on 455 persons of both sexes, from 1 to 73 years of age, who live permanently in the area and voluntarily accepted to be included in the study. Both antigens were employed at the same time in order to evaluate crossed type reactions. Of the 455 persons, 52 (39 males-13 females) were reactive to paracoccidioidin (11.4%), with an increasing prevalence with age. According to previous data, these results would indicate an increase in the index of human infection by P. brasiliensis, and this may be related to the important changes in climatic and environmental conditions introduced in the area in the last years.

Adolescent↗

PubMed2000

Histoplasmosis: an unusual presentation.

Histoplasma capsulatum (HC) infection is rare in India. We document a case of unilateral adrenal histoplasmosis in a 56 year male. The patient presented with hepatosplenomegaly, unilateral adrenal mass and significant weight loss. Since FNAC of adrenal mass was inconclusive, he underwent splenectomy, adrenalectomy and liver biopsy, histology of these specimens revealed HC only in adrenal mass. Subsequently, histoplasmin test was also performed which was also found to be positive. He responded well to parenteral amphotericin B and is under regular follow-up with no complaints now.

Adrenal Gland Diseases↗

PubMed1975

Retention of albino and brown phenotypes of Histoplasma capsulatum by liquid nitrogren refrigeration.

Pathogenic differences between albino (A) and brown (B) phenotypes of Histoplasma capsulatum for experimental animals, and serological differences between A- and B- derived histoplasmins or yeast-phase antigens, necessitate the retention of these phenotypes in culture for diagnoses and epidemiologic studies. Selected strains of A and B types were frozen in liquid nitrogen (LN) and stored for 6-9 months in the vapor phase of a LN refrigerator (-165 degrees C). The strains were tested by using Berliner's method for differentiation of these two phenotypes. The results have proved that the LN refrigeration can be used for long-term conservation to prevent the conversion of B type into the A type in vitro.

Color↗

PubMed2003

[A primary investigation on disseminated histoplasmosis in Hubei].

OBJECTIVE: To investigate the epidemiologic features of disseminated histoplasmosis (PDH) in Hubei province. METHODS: Bone marrow smears of 12 patients diagnosed as Kala-azer in Hubei province including 4 patients in Jingsan, 2 patients in Shashi and each 1 in Yichang, Jinmen, Zhongxiang, Luotian, Xianning and Guanghua respectively were re-examed under microscope. Peripheral blood and bone marrow smears of several patients were detected. After inoculated the bone marrow, peripheral blood, liver and spleen tissue of patients in MLI, the single colony was trans-inoculated in BHIB, SDA and CMA and incubated at 25 degrees C and 35 degrees C. Bone marrow, peripheral blood and bacterial fluid of yeast-phase Histoplasma capsulatum (H.cap) were injected into the abdominal cavity of Kunming mice and nude mice. When symptoms and signs developed, the spleen tissue was separated, then observed under microscope and cultured. Mycelium-phase and Yeast-phase H.cap were inoculated in urase and gelatin medium, then incubated at 25 degrees C and 35 degrees C. Histoplasmin was injected subcutaneously into patients, and then followed for 48 - 72 hours. Amphotericin B was selected to treat the PDH patients. RESULTS: Moriform cell cluster and sausage-shaped cell were not observed in mononuclear-macrophages in the bone marrow smears from 12 patients. Leishman-Donovan body was found only in one patient. There wasn't kinetoplast in the cellular plasm of spores in 11 patients and no transeptae was found. The reaction of H.cap to urease was positive and H.cap did not liquefy the gelatin. It appeared to be mycelium-phase at 25 degrees C but no penicillus and catenulate conidia was found. The characteristic denticle macroconidia was observed but produced red coloring matter. It also appeared to be yeast-phase at 35 degrees C. Yeast-phase spores were observed under microscope. No sausage-shaped spore and transeptae were identified. H.cap could be acquired in the spleen tissue in Kunming mice and nude mice. Bacterium forms, characteristics under microscope and biochemical reaction of mycelium-phase and yeast-phase H.cap were different from some other kinds of dimorphic fungi such as Penicillium marneffei and Histoplasm duboisii etc. CONCLUSION: There were scattered epidemics of PDH in Hubei province. The detection rate of PDH was higher in the southeast area then in the northwest area. The golden standards of clinic diagnosis were mycological culture and inoculation to animals. Amphotericin B was necommended as the first choice for treatment.

Adolescent↗

PubMed1986

Effects of Histoplasma capsulatum products on the functional activity of alveolar macrophages.

The possibility that Histoplasma capsulatum may affect the activities of alveolar macrophages through products of either secretion or lysis was examined. Varying amounts of histoplasmin (HP), the filtrate of cultures of H. capsulatum, were added to monolayer cultures of alveolar macrophages of Wistar rats, and the effects of the filtrate on viability, ingestion rate, random migration, adhesive properties and microbial killing capacity were evaluated. No clear cytotoxic or cytopathogenic effects were produced at any dose tested. The endocytic rate was enhanced when HP (0.2 micrograms) was added, the effect being due to the recruitment of non-phagocytosing cells. Alveolar macrophages that had remained nonadherent after 3 h of incubation adhered to glass slides after HP was added. Dose-dependent inhibition of random migration of macrophages was produced with the addition of HP. However, the microbial killing capacity was not modified significantly at any dose of the H. capsulatum product.

Animals↗