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A case of presumed ocular histoplasmosis was diagnosed in a diabetic patient, and an angiographic study of the ocular lesions was carried out. Results of histoplasmin skin test and the specific complement fixation test were negative. The epidemiologic aspects of histoplasmosis in Europe are considered.
This paper is part of the author's free-teaching theses presented in 1974, in which he has studied 436 persons not carriers of the B.S.A. and other diseases, resident in Campos, Conceição de Macabu and Quissamã (urban and rural zones). Tests were applied in these patients by using standardized antigen of polysaccharide of Paracoccidioides brasiliensis of histoplasmine. The author concluded that there has been existence of the B.S.A.-infection which means what is called "INFEKT". He emphasizes that the epidemiologic researches have important role in the estimation of the incidence of the B.S.A.
This report deals with three observations of Histoplasma mycosis (one acquired in Western Africa - large cell form; two in the USA - classical form) which were diagnosed from 10 to 35 years after primary infection. The laboratory diagnosis was based on immunological, histopathological and clinico-epidemiological data, since in none of the cases material was available for mycological culture. The histoplasmin skin test is considered to be the most sensitive procedure. A positive outcome may support other evidence or suspicion and may deliver an valid clue - particularly among individuals from non-endemic areas-to consider the possibility of Histoplasma infection. The demonstration of serum antibodies may assist in establishing a correct diagnosis in such cases.
Sixteen healthy adults had serial studies of delayed-type skin test reactivity and in vitro lymphocyte blastogenesis to several antigens over a period of 7 months. In many subjects blastogenesis varied broadly from month to month without apparent cause. Responses to all antigens usually increased or decreased together on sequential testing. Blastogenesis to coccidioidin appeared to result largely from cross-reaction with histoplasmin. Humoral factors were not demonstrably responsible for these changes. Blastogenesis rose consistently and non-specifically in subjects following revaccination to vaccinia virus. These studies reflect the lymphocyte blastogenesis reaction as a dynamic equilibrium, subject to spontaneous variation, and responding non-specifically to stimuli such as vaccination. Whatever the causes for these changes, it is clear that serial determinations of blastogenesis response to various antigens do not carry the apparent consistency of the skin test response to that antigen, and single tests must be cautiously interpreted.
We have prepared a detergent extract from the cell wall and cell membrane of Histoplasma capsulatum yeast cells that is recognized by T cells from mice immunized with viable organisms or with the extract. A 62-kd antigen from this extract has been isolated and has been shown to be antigenic and to confer protective immunity in mice. In this study, we examined the in vitro proliferative response by human lymphocytes and human T-cell clones to both the extract from the cell wall and cell membrane and the 62-kd antigen, termed HIS-62. Seven healthy individuals were identified whose peripheral blood mononuclear cells responded to the cell wall and cell membrane extract from H. capsulatum yeast cells. Mononuclear cells from all seven individuals recognized histoplasmin. T-cell clones were generated from peripheral blood mononuclear cells from a single person using the extract from cell wall and cell membrane as the antigenic preparation. Nineteen clones were propagated; all expressed the surface phenotype CD3+, CD4+, T-cell receptor alpha/beta +. The clones were antigen-specific. Of 17 clones studied, none responded to extracts from Blastomyces dermatitidis or Coccidioides immitis or to tetanus toxoid. Sixteen of 19 clones recognized HIS-62 in vitro. Additional analysis revealed that cells from each of the seven individuals who responded to the extract mounted a proliferative response to HIS-62. Thus, the extract from the cell wall and cell membrane and HIS-62 are targets of the human cell-mediated immune response to H. capsulatum. Moreover, HIS-62 appears to be an immunodominant antigen.
Antigens in coccidioidin were compared with purified subfractions via tandem immunoelectrophoresis (IEP) and by a combination of advancing line and crossed IEP. Rocket IEP was suitable for titrating the reactions and showing the relationship between column fractions. These techniques required multicomponent antisera produced by hyperimmunization over many months and by the use of known standard migration pairs. The IEP variations were used to chart the development of antisera against coccidioidin factors, to monitor antigen purifications, and to test the immunochemical homogeneity of an isolated antigen. Mannose-based heteroglycans of Cryptococcus neoformans were recovered from the culture filtrate. After precipitation of the major viscous glucuronoxylomannan (GXM) with ethanol or cetyltrimethylammonium bromide, the supernate is reserved because it contains a galactoxylomannan (GalXM). After removal of glucuronic acid from the GXM, the resulting xylomannan of serotype A was amenable to 13C-nuclear magnetic resonance (NMR) spectrometry; it revealed nonreducing xylose, alpha-1,3-mannose, and alpha-1,2/1,3 disubstituted mannose, thus confirming by an independent means what was previously known. The characterization sequence of GalXM included: (1) gas-liquid chromatography (GLC) of neutral sugars as peracetylated aldononitriles; (2) methylation-fragmentation GLC mass spectrometry to determine the glycosidic linkages; and (3) 13C-NMR showing similarities to mannan of Saccharomyces cerevisiae. Affinity chromatography of the GalXM on concanavalin A separated the galactoxylo component from an adsorbed mannoprotein. Selection of monoclonal antibodies (MAbs) relies on presumptive enzyme immunoassays (EIAs) or radioimmunoassays for rapid screening of clones and for determination of isotypes; however, higher resolution confirmatory tests are needed to obtain MAbs of desired specificity. MAbs against Candida tropicalis mannan were labeled with horseradish peroxidase to use for detecting mannan in serum. MAbs against the partially purified "m" factor of histoplasmin were characterized by the enzyme-linked immunoelectro-transfer blot technique (EITB), revealing unsuspected complexity in the antigen. Secreted proteins of Nocardia asteroides were isoelectrically focused; three proteins, identified by EITB as promising to be specific for that actinomycete, were cut out of gels and used to immunize mice for production of MAbs. The fimbriae of Actinomyces viscosus and A. naeslundii that mediate lactose-reversible coagglutination with Streptococcus sanguis have been used to evoke MAbs.(ABSTRACT TRUNCATED AT 400 WORDS)
Soluble antigens of whole yeast-phase cells were extracted with a 0.1 M phosphate buffer containing 0.1 M sodium chloride and 0.02% iodacetate. After being separated by differential filtration into fractions less than or greater than 50,000 daltons these antigens were purified by molecular sieve and chromatographic separations on ionic exchange resins. Two high molecular weight fractions obtained from diethylaminoethyl-cellulose (DEAE) at pH 8.0 and 7.0 with tris (hydroxymethyl) aminomethane (Tris) buffer were M antigens; those obtained at pH 4.0 and 4.0 with salt were H antigens. The four fractions had protein to carbohydrate ratios of 7.3, 14.0, 8.4, and 6.5 respectively, and all had essentially the same amino acid composition with no methionine and tyrosine and little histodine, arginine, phenylalanine and lysine. They had high concentrations of glucose, less mannose and traces of galactose. The low molecular weight fractions had the new complex "Y antigen", M antigen with protein to carbohydrate ratios of 1.4, 1.4 and 0.3 respectively. The amino acid and sugar composition of Y antigen strongly resembled the composition of the low molecular weight H and M antigens. Unlike the high molecular weight antigens, these low molecular weight antigens had methionine in relatively high concentrations; they had the same sugars as their respective high molecular weight counterparts. The yeast phase antigens differed from their respective mycelial counterparts in the following ways: glucose was the major sugar in the yeast phase with less amounts of mannose and traces of galactose, whereas in the mycelial antigens, mannose was the major sugar, with lesser amounts of galactose, and hexosamine. The H and M antigens of the yeast phase had high concentrations of glycine and alanine, whereas in the mycelial phase, these antigens had high concentrations of threonine and proline; the H and M antigens of the yeast phase had 5 to 16 times the protein to carbohydrate ratio observed for the same antigens of histoplasmin.
The specific delayed-type hypersensitivity (DTH) response was evaluated in resistant (A/SN) and susceptible (B10.A) mice intraperitoneally infected with yeasts from a virulent (Pb18) or from a non-virulent (Pb265) Paracoccidioides brasiliensis isolates. Both strains of mice were footpad challenged with homologous antigens. Pb18 infected A/SN mice developed an evident and persistent DTH response late in the course of the disease (90th day on) whereas B10.A animals mounted a discrete and ephemeral DTH response at the 14th day post-infection. A/SN mice infected with Pb265 developed cellular immune responses whereas B10.A mice were almost always anergic. Histological analysis of the footpads of infected mice at 48 hours after challenge showed a mixed infiltrate consisting of predominantly mononuclear cells. Previous infection of resistant and susceptible mice with Pb18 did not alter their DTH responses against heterologous unrelated antigens (sheep red blood cells and dinitrofluorobenzene) indicating that the observed cellular anergy was antigen-specific. When fungal related antigens (candidin and histoplasmin) were tested in resistant mice, absence of cross-reactivity was noted. Thus, specific DTH responses against P. brasiliensis depend on both the host's genetically determined resistance and the virulence of the fungal isolate.
The present work was undertaken to obtain epidemiological data on the extent and distribution of Histoplasma capsulatum var. capsulatum and Paracoccidiodes brasiliensis infections south of the Chuscha, Gonzalo and Potrero areas of Argentina. Skin tests surveys of the human population with histoplasmin and paracoccidioidin were carried out in the permanent population of those localities. The infection index of the population showed that the area south of Chuscha has a high-prevalence of histoplasmosis capsulati. The Gonzalo and Potrero areas, according to their rates of infection also can be considered to have a relatively high prevalence of this disease. The frequency of individuals infected with P. brasiliensis suggests that the level of exposure to this fungus is considerable, especially in Gonzalo where the frequency of infection was 9.23%. The endemic areas of both diseases can be superimposed, as occurs in the northeastern part of Argentina.
PURPOSE: To investigate the incidence of remote subclinical blastomycosis in a high-risk population of forestry workers. PATIENTS AND METHODS: The study consisted of 39 male forestry workers from northern Minnesota and northern Wisconsin, areas endemic for blastomycosis but not for histoplasmosis. All subjects were histoplasmin skin test-negative, and none had ever been diagnosed with blastomycosis or pneumonia. An antigen-specific lymphocyte stimulation assay was performed to determine the presence of blastomycosis. RESULTS: Peripheral blood lymphocytes from 12 of 39 subjects demonstrated specific antigen-induced proliferation when stimulated with a purified alkali- and water-soluble antigen derived from the cell wall of Blastomyces dermatitidis. CONCLUSION: The finding that 30% of these men had evidence of previous blastomycosis suggests that subclinical cases do occur sporadically, and are probably more common than diagnosed symptomatic cases. This is similar to histoplasmosis, in which the majority of infections are subclinical. However, the reservoir of persons with previous undiagnosed blastomycosis is probably small compared to the huge number of persons (perhaps 30 million) with prior histoplasmosis.
In 20 patients idiopathic focal subretinal neovascularization was characterized by a solitary focus of subretinal neovascularization at or near the fovea, associated with serous or hemorrhagic detachment of the overlying and adjacent sensory retina, or both. Although the lesions resembled the neovascular membrane seen in the presumed ocular histoplasmosis syndrome, none of the other associated characteristic ophthalmoscopic findings, considered essential to make the latter diagnosis, were apparent. In this group of patients, the incidence of positive histoplasmin skin tests was no greater than in the general population. Of the 20 patients, two had bilateral disease. In no case were there any other lesions of any kind in the afflicted or the opposite eye. The disease is self-limited over a variable period of time, but may result in extensive scarring with loss of central vision.
Six black patients had fundus lesions diagnostic of the presumed ocular histoplasmosis syndrome. All patients had peripapillary changes or peripheral punched-out chorioretinal lesions, or both. Five of the six had macular subretinal neovascularization, disciform scarring, or an atrophic macular lesion, and one patient had a macular hole; four of five patients tested had a positive histoplasmin skin test. The macular involvement was bilateral in three of the six cases. HLA B-7 was present in one of four patients who had HLA typing. Macular involvement can occur in blacks with the presumed ocular histoplasmosis syndrome.
Sixty-one subjects, preselected for mumps sensitivity, were entered into a double-blind protocol to standardize Mumps Skin Test Antigen. Four lots of mumps antigen selected on the basis of in vitro potency tests were used. Four other antigens, Histoplasmin, Dermatophytin-O, Dermatophytin, and fluid tetanus toxoid were also tested; positive reactions for these four antigens occurred in 48, 68, 25, and 43% of individuals, respectively. The mumps lots exhibited delayed hypersensitivity with positivity ranging from 63 to 67% at 20 CFU/ml and 77 to 84% at 80 CFU/ml in the acceptable lots. Side effects were primarily local and minor in nature. Mumps Skin Test Antigen is a useful measure of the integrity of the immune system, but lacks complete specificity because of local dermal factors.
Serum samples from 60 subjects with confirmed HIV-1 infection including 28 AIDS patients and 32 carriers were examined by immunodiffusion for precipitating antibodies to antigens of Histoplasma, Blastomyces and Candida. Seven of the subjects, four patients and three carriers, showed antibodies to histoplasmin prepared from mycelial cultural filtrate of Histoplasma capsulatum var. capsulatum and H. capsulatum var. duboisii although without any clinical signs of classical or African histoplasmosis. Another eight subjects comprising five patients and three carriers demonstrated antibodies to yeast cell antigen of Candida albicans; three of the patients had oral lesions clinically suggestive of Candida infection. None of the serum samples revealed antibodies to "A" antigen (yeast cell antigen) of Blastomyces dermatitidis.
Reports of ocular histoplasma mycosis demonstrated serologically and in tissue are rare in Europe. This is principally due to the fact that histoplasmosis is not endemic in Europe (in contrast to the USA). A second reason is that it is hard to find laboratories which have experience in the differential diagnosis of histoplasmosis and forms of uveitis. In cases of uveitis it would be desirable to include histoplasmosis in the differential diagnosis and to use more staining methods (silver nitrate methenamine, fluorescein serology) and immunologic tests (intracutaneous test with histoplasmin, complement fixation test, countercurrent immuno-electrophoresis) for histoplasmosis. Report on a case of ocular histoplasmosis, positive in the skin test and in immunodiffusion, contracted 19 years previously in Mississippi, USA.
Histoplasmosis is a common opportunistic infection in patients with human immunodeficiency virus (HIV) infection who reside in areas where Histoplasma capsulatum is endemic. We undertook a prospective study of a cohort of 304 HIV-Infected patients in Kansas City from October 1990 through March 1993 to define the incidence-specific risk factors, and pathophysiology of histoplasmosis. The annual incidence of histoplasmosis was 4.7%; 74% of the patients with histoplasmosis were symptomatic (all of whom had disseminated disease). A history of exposure to chicken coops, a positive baseline serology for complement-fixing antibodies to Histoplasma mycelium antigen, and a baseline CD4+ lymphocyte count of < 150/microL were associated with an increased risk for histoplasmosis. Histoplasmin reactivity and the presence of pulmonary calcifications were not useful markers for patients at high risk. Symptomatic infection occurred in 9.9% of patients with evidence of prior exposure to H. capsulatum, in 4.0% of patients without documented prior exposure, and in 3.0% of patients who were anergic; these findings suggest that the pathophysiology of histoplasmosis in patients with AIDS involves reactivation of latent infection in some cases and dissemination of exogenously acquired infection in other cases.
A case of lung cavity with fungus ball is reported in a patient subsequent to the treatment of tuberculosis for a year. Fungal serologic titers for histoplasmin, blastomycin, coccidiodin, and aspergillin were negative. Surgical resection of the cavity and to be done because of episodes of hemoptysis. Numerous hyphae formed into a compact mass consistent with aspergilloma were seen in the cavity. The cultures for fungi were negative on material from the surgical specimen. Immunodiffusion studies of sera obtained prior to surgery were positive for Pseudallescheria boydii and very informative in assessing the correct morphologic characteristics of the organism.
Disseminated histoplasmosis is an AIDS-defining illness that occurs in about 5% of AIDS patients residing in histoplasmosis-endemic areas of the United States (the Mississippi and Ohio river valleys). This disease develops as a result of acute infection and perhaps also as the result of reactivation of latent infection: cases reported from areas such as New York City, where histoplasmosis is not endemic, are most likely due to reactivation of an infection acquired earlier in a histoplasmosis-endemic area, while cases in histoplasmosis-endemic areas are most likely due to acute infection, especially in outbreak settings. Disseminated histoplasmosis in HIV-infected patients is usually associated with advanced immunosuppression, with CD4+ lymphocyte counts of < 75/mm3. Currently, histoplasmin skin testing of HIV-infected patients does not seem to be useful in detecting previous exposure and therefore is not helpful in identifying groups of patients who are at risk for dissemination and who should be targeted for preventive efforts. The current public health recommendation for HIV-infected patients is to avoid exposure to sites likely to harbor high levels of Histoplasma capsulatum, such as chicken coops and bird roosts. The role of chemoprophylaxis is not clear, but an ongoing study by the Mycoses Study Group is evaluating the role of prophylactic itraconazole. If strategies for the prevention of disseminated histoplasmosis in HIV-infected patients are to be improved, studies must better define the risk factors for this opportunistic infection, describe its natural history, and develop more reliable tests to predict its development.