Case of disseminated African histoplasmosis in a baboon

An adult red baboon (Papio cynocephalus papio) had a severe disseminated case of African histoplasmosis (Histoplasma capsulatum var. duboisii) with skin lesions from small pustules to ulcerative granulomas. Osteolytic lesions were seen radiographically. Treatment with ketoconazole for 6 months was unsuccessful.     

Diminution of antifungal activity of fluconazole associated with ibuprofen and piroxicam in experimental histoplasmosis of hamsters (Mesocricetus auratus)

The aim of this study was to determine if tha association of non-steroid antiinflammatory drugs (piroxicam and ibuprofen) with fluconazole, affects the antifungal activity of the azole compound, in an experimental model histoplasmosis in hamsters (Mesocricetus auratus). Sixty hamsters were intracardially inoculated with 4x10(6) yeasts of Histoplasma capsulatum var. capsulatum. Treatments began one week after the challenge and continued for three weeks. The hamsters were divided in six groups of ten animals each and received the following treatment: 1- fluconazole 8 mg/kg/day; 2- ibuprofen 20 mg/kg/day; 3- piroxicam 20 mg/kg/day; 4- fluconazole+ibuprofen; 5- fluconazole+piroxicam and 6- only received the solvent of these drugs. One week after ending the treatment, all the animals were sacrified and the evaluation of the treatments was based on the results of blood cultures, on the determination of colony forming units per gram of spleen, and the histopathologic studies of the same organ. The animals treated with fluconazole plus ibuprofen or piroxicam showed more colony colony forming units per gram (3.9x10(7) and 3.3x10(7)) when compared with the animals treated with fluconazole alone (0.9x10(7)). The histopathologic results of the hamsters that received fluconazole showed well-organized granulomas with few yeast-like elements inside the macrophages. In contrast, those which received fluconazole associated with antiinflammatory drugs presented lax granulomas containing numerous yeast-like elements. These findings let us to conclude that non-steroids antiinflammatory drugs diminish the antifungal efficacy of fluconazole in this animal model.     

Characterization of the Histoplasma capsulatum-induced granuloma

Rising rates of Histoplasma capsulatum infection are an emerging problem among the rapidly growing population of immune-compromised individuals. Although there is a growing understanding of systemic immunity against Histoplasma, little is known about the local granulomatous response, which is an important component in the control of infection. The focus of this article is the characterization of Histoplasma-induced granulomas. Five days after i.p. infection, infected macrophage appear in the liver and lung; however, no granulomas are apparent. Two days later, well-formed sarcoid granulomas are abundant in the lung and liver of infected mice, which contain all visible Histoplasma. Granulomas are dominated by macrophage and lymphocytes. Most of the Histoplasma and most of the apoptotic cells are found in the center of the lesions. We isolated liver granulomas at multiple time points after infection and analyzed the cellular composition, TCR gene usage, and cytokine production of granuloma-infiltrating cells. The lesions contain both CD4+ and CD8+ T cell subsets, and T cells are the primary source of IFN-gamma and IL-17. The main source of local TNF-alpha is macrophage. Chemokines are produced by both infiltrating macrophage and lymphocytes. Dendritic cells are present in granulomas; however, T cell expansion seems to occur systemically because TCR usage is very heterogeneous even at the level of individual lesions. This study is the first direct examination of host cellular responses in the Histoplasma-induced granuloma representing the specific interface between host and pathogen. Our studies will allow further analysis of key elements of host Histoplasma interactions at the site of chronic infection.     

Clinical and pathological features of six cases of sarcoidosis presenting with renal failure

Six patients with biopsy-proven renal sarcoidosis presented with renal failure of unknown origin; in none was the diagnosis of sarcoidosis initially considered. The serum creatinine concentration at the time of presentation ranged from 265 to 1380 μmol/l (3.0 to 15.6 mg/dl), with a mean of 787 μmol/l (8.9 mg/dl). Although only two patients were hypercalcemic at the time of presentation, the 24-hour urinary excretion of calcium was increased in three of the four patients in whom it was measured, and renal calculi were present in one case. Renal biopsy revealed interstitial nephritis and tubular atrophy in all cases, as well as nephrocalcinosis in three cases and noncaseating granulomas negative for acid-fast bacilli in four cases. In each patient steroid therapy led to a rapid improvement in renal function (mean post-treatment serum creatinine level 274 μmol/l [3.1 mg/dl]). The follow-up period ranged from 8 months to 8 years (mean 3.0 years). In three patients renal function remained stable with low-dose steroid therapy. In two cases recurrent hypercalcemia and deteriorating renal function accompanied steroid withdrawal but resolved with its reinstitution. In one additional case reversible deterioration in renal function accompanied tapering of the steroid dose; however, there was no hypercalcemia.This report emphasizes the importance of considering sarcoidosis in the differential diagnosis of acute renal failure of unknown origin. Long-term follow-up of such patients is essential, as relapse is common.     

Unusual Recurrence of Hypercalcemia Due to Concurrent Parathyroid Adenoma and Parathyroid Sarcoidosis with Lymph Node Involvement

ObjectiveTo describe a patient presenting with the rare findings of synchronous parathyroid adenoma and parathyroid sarcoidosis.MethodsWe describe the clinical history, physical examination findings, laboratory values, imaging findings, and pathologic data of a man who developed recurrent se- vere hypercalcemia after successful parathyroidectomy.ResultsA 67-year-old man had the following initial blood test results: calcium, 11.1 mg/dL (reference range, 8.5-10.6 mg/dL); albumin 4.0 g/dL (reference range, 3.2-5.2 g/dL); intact parathyroid hormone, 166 pg/mL (refer- ence range, 10-69 pg/mL); creatinine, 1.9 mg/dL; 25-hy- droxyvitamin D, 15 ng/mL (reference range, 30-80 ng/ mL); and 1, 25-dihydroxyvitamin D, 44 pg/mL (reference range, 16-72 pg/mL). Chest x-ray was normal, and delayed images from a technetium Tc 99m sestamibi scan showed increased activity in the right lower pole of the thyroid. Two months after successful parathyroidectomy, the pa- tient was admitted to the hospital with a serum calcium concentration of 17 mg/dL. Pathologic examination of the resected gland confirmed the diagnosis of parathyroid ad- enoma, and subsequent review disclosed the presence of noncaseating granulomas within the adenoma.ConclusionsSarcoidosis with parathyroid involve- ment causing severe hypercalcemia is unique to this case.Recurrent hypercalcemia after successful resection of a parathyroid adenoma may require consideration of poten- tial causes other than the initial diagnosis. (Endocr Pract. 2010;16:463-467)     

The Emerging Role of Denosumab in the Long-Term Management of Parathyroid Carcinoma-Related Refractory Hypercalcemia

Objective: The main cause of death in patients with parathyroid carcinoma is parathyroid hormone (PTH)-induced hypercalcemia. To date, the management of hypercalcemia has been based on the use of bisphosphonates and calcimimetic agents. In recent reports, the use of denosumab has shown encouraging results in cases of refractory hypercalcemia of malignancy. Our objective is to present a case of successful management of resistant hypercalcemia due to parathyroid carcinoma with denosumab, to review similar cases from the literature, and to propose denosumab's use in the clinical management of PTH-induced refractory hypercalcemiaMethods: Presentation of a case report and review of the literature for cases of parathyroid carcinoma–mediated hypercalcemia successfully treated with denosumab.Results: A 71-year-old man with metastatic parathyroid carcinoma was referred to our department for uncontrolled hypercalcemia, resistant to treatment with bisphosphonates and cinacalcet. Treatment with denosumab (120 mg per month) in addition to cinacalcet (180 mg per day) resulted in normalization of calcium levels and maintenance within the normal range for an observation period of 11 months. Review of the literature revealed 4 case reports and a letter to the editor, all of which reported the successful treatment of resistant hypercalcemia associated with parathyroid carcinoma.Conclusion: Based on the above findings of the effectiveness of denosumab in controlling refractory hypercalcemia, its safety in renal failure and the fact that denosumab may reduce PTH-induced bone loss, we endorse its use in the management of hypercalcemia in patients with parathyroid carcinoma and perhaps other conditions with PTH-induced hypercalcemia.Abbreviations: CT = computed tomography IV = intravenous PTH = parathyroid hormone     

A case of hypocalciuric hypercalcemia without family history.

Familial hypocalciuric hypercalcemia (FHH) is usually characterized by asymptomatic hypercalcemia, mild hypermagnesemia, and low urinary calcium excretion, and is occasionally associated with pulmonary fibrosis. It is inherited as an autosomal-dominant, and no sporadic case of hypocalciuric hypercalcemia has been heretofore reported. This report describes a patient with hypocalciuric hypercalcemia completely compatible with FHH but with no family history, suggesting that the most likely diagnosis is "nonfamilial" hypocalciuric hypercalcemia. We propose that the urinary excretion of calcium be examined in all patients with hypercalcemia, hypophosphatemia, and increased PTH before neck surgery, even if patients have no family history of hypercalcemia.     

Amphotericin Pharmacophobia

Five cases are described in which fear of the possibly hazardous effects of giving amphotericin to patients with kidney disease resulted in death from progressive infection by an amphotericin-sensitive fungus (Cryptococcus neoformans in three cases, Blastomyces dermatitidis in one case, and Histoplasma capsulatum in one case).     

Genetic diversity of Histoplasma capsulatum strains in Brazil

This study establishes the genetic relatedness among Brazilian Histoplasma capsulatum samples obtained from different sources. A PCR-based random amplified polymorphic DNA (RAPD) assay was used to delineate polymorphisms among isolates in geographically diverse regions in Brazil. RAPD fingerprints revealed distinct DNA profiles and provided a high level of discrimination among H. capsulatum strains from different locations. Cluster I was composed of H. capsulatum isolates from the northeast region. The majority of strains from southeast and south were categorized as major cluster II. The strain 84564 from Rio de Janeiro State showed no genetic correlation to any of the isolates from the same state. The RAPD patterns of H. capsulatum isolates from Goias (Cluster III) were unrelated to DNA fingerprints observed among the other H. capsulatum strains (48% similarity). This study is the first report that stratifies the clusters of H. capsulatum strains from Brazil by molecular typing and associates them with the geographical origin.     

Comparative study of the effect of thiabendazole and fungizone on Histoplasma capsulatum in macrophages.

The antifungal properties of Fungizone (amphotericin B intravenous solution) and thiabendazole on Histoplasma capsulatum within guinea pig macrophages were compared using the staining method and a newly developed plating method to determine the viability of intracellular H. capsulatum. The two methods were compared to determine the effectiveness of Fungizone and thiabendazole on H. capsulatum within macrophages. Fungizone was fungicidal for intracellular H. capsulatum, killing 99.9% of the yeasts at a concentration of 0.5 microgram/ml. There was some indication that non-viable intracellular yeasts were stained which could result in misinterpretation of the effectiveness of Fungizone using the staining method unless the yeasts are very closely examined for staining abnormalities. There was a good correlation between the two methods to demonstrate suppression of the multiplication of intracellular H. capsulatum in macrophages treated with 50 microgram/ml of thiabendazole. Thiabendazole was lethal for some intracellular H. capsulatum.     

Disseminated histoplasmosis with lesions restricted to the larynx in a patient with AIDS. Report of a case and review of the literature

Histoplasmosis is an endemic and systemic mycosis, caused by the dimorphic fungus Histoplasma capsulatum var capsulatum. Disseminated disease in immunocompromised patients generally results from the reactivation of latent foci after a prolonged period of asymptomatic infection. We report a case of laryngeal histoplasmosis as the unique clinical manifestation of a progressive form of the disease in a patient with advanced HIV/AIDS disease. Histopathological analysis of laryngeal biopsy smears revealed granulomas containing Histoplasma-like organisms. Treatment with amphotericin B followed by itraconazole resulted in complete remission of laryngeal lesions. To our knowledge, this is the third case report of laryngeal histoplasmosis in a patient with AIDS.     

African histoplasmosis: a review

African histoplasmosis caused by Histoplasma capsulatum var. duboisii is an important deep mycosis endemic in Central and West Africa and in the island of Madagascar. The disease is characterized by presence of granulomatous lesions in the skin, subcutaneous tissues and bones. Lungs and other internal organs are rarely involved. The natural reservoir of the etiological agent has only been recently discovered in a bat cave in Nigeria. The status of asymptomatic infection is not certain. Investigations on skin and serum reactivity have suggested frequent prevalence of asymptomatic infections due to H. capsulatum var. duboisii among the residents in the vicinity of the cave microfocus of the fungus. The exact portal of entry into the body is not known, but inhalation into the lungs and direct inoculation in the skin have been incriminated. Laboratory diagnosis is confirmed by in vitro conversion into large yeast forms (8-15 mum in diameter) and by the demonstration of these forms within giant cells of tissues of experimentally infected animals There are no major clean-cut physiological differences between the two varieties, viz. capsulatum and duboisii. The cell wall of H. capsulatum var duboisii contains a glucan with beta 1-4 linkages in addition to a galactomannan shared with H. capsulatum var. capsulatum. Like the var. capsulatum var. duboisii has marked proteinase and collagenase activities in both mycelial and yeast forms, suggesting a possible pathogenic role for these enzymes. Both varieties have a common exoantigen. The yeast form of H. capsulatum var. duboisii contains the antigen found in the serotype 1,4 of var. capsulatum. A monoclonal antibody test has been developed that can recognize some epitopes in H. capsulatum var. capsulatum but not in the var. duboisii. There is need to develop specific serological diagnosis for the disease. Also there should be greater international awareness about African histoplasmosis. Amphotericin B and several antimycotic azoles like ketoconazole, itraconazole and fluconazole have been successfully employed for treatment.     

Hypercalcemia Secondary to Gastrointestinal Stromal Tumors: Parathyroid Hormone-Related Protein Independent Mechanism?

ObjectiveHypercalcemia is a common paraneoplastic manifestation of many malignancies like breast, ovarian, and squamous-cell cancers of head and neck; however, there have been only a few case reports of hypercalcemia associated with gastrointestinal stromal tumors (GISTs). We report a case of GIST presenting with hypercalcemia without any osseous metastasis and provide a literature review regarding the mechanisms of hypercalcemia and therapeutic strategies.MethodsWe present a report of case and a review of the relevant literature.ResultsA 52-year-old woman with history of localized breast cancer in remission and a pelvic 13 × 12 cm GIST with peritoneal, liver, and lung metastases presented with hypercalcemia of 14.3 mg/dL (8.5-10.5 mg/dL). Parathyroid hormone-related protein (PTHrP) was undetectable, intact parathyroid hormone (PTH) was appropriately low at 1 pg/mL (10-65 pg/mL), and 1,25 dihydroxy vitamin D (1,25 OH₂ vit D) was elevated at 131 pg/mL (18-78 pg/mL) with normal renal function. Calcium responded transiently to tyrosine kinase inhibitor therapy and bisphosphonates but within a year, she expired due to tumor progression.ConclusionGIST is a rare cause of hypercalcemia. In addition to PTHrP expression, direct tumor production of 1,25(OH)₂ vit D or 1-α hydroxylase enzyme resulting in activation of 25-hydroxy vitamin D may be an alternative mechanism in GIST-related hypercalcemia. Therapy with tyrosine kinase inhibitors and bisphosphonates is recommended, though prognosis is poor. Further investigations are needed to characterize the etiology and management of hypercalcemia in these patients. (Endocr. Pract. 2013;19: e158-e162)     

Imported and autochthonous histoplasmosis in Italy: new cases and old problems

In the past the Italian soil was considered as a low-endemic pabulum for H. capsulatum var. capsulatum and only few autochthonous cases of histoplasmosis were reported in Italy, especially in the Po valley. The aim of the paper was to evaluate this possibility by reviewing the literature and providing our own personal data. Four additional cases of histoplasmosis were observed during 1999-2003 in AIDS immigrant or in Italian citizens, and in travellers to endemic areas. One of the AIDS patients was an autochthonous case of histoplasmosis. The Italian literature was reviewed. Recent cases and literature data confirm the possible autochthonous presence of histoplasmosis in Italy, especially in the Northern regions.     

Adhesion of Histoplasma capsulatum to pneumocytes and biofilm formation on an abiotic surface

The pathogenic fungus, Histoplasma capsulatum, causes the respiratory and systemic disease 'histoplasmosis'. This disease is primarily acquired via inhalation of aerosolized microconidia or hyphal fragments of H. capsulatum. Evolution of this respiratory disease depends on the ability of H. capsulatum yeasts to survive and replicate within alveolar macrophages. It is known that adhesion to host cells is the first step in colonization and biofilm formation. Some microorganisms become attached to biological and non-biological surfaces due to the formation of biofilms. Based on the importance of biofilms and their persistence on host tissues and cell surfaces, the present study was designed to investigate biofilm formation by H. capsulatum yeasts, as well as their ability to adhere to pneumocyte cells. H. capsulatum biofilm assays were performed in vitro using two different clinical strains of the fungus and biofilms were characterized using scanning electron microscopy. The biofilms were measured using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium-hydroxide (XTT) reduction assay. The results showed that both the H. capsulatum strains tested were very efficient at adhering to host cells and forming biofilm. Therefore, this is a possible survival strategy adopted by this fungus.     

Albumin-Corrected Calcium and the Prevalence and Categories of Hypercalcemia in Hospitalized Patients With 1-Year Follow-Up of Undiagnosed Cases

ObjectiveTo assess the impact of using corrected calcium versus total calcium on hypercalcemia case detection in hospitalized patients.MethodsPatients hospitalized from June 2012 to June 2017 with a corrected calcium level of ≥10.5 mg/dL were identified by medical record review. One-year follow-up data through June 2018 were acquired. Albumin-corrected calcium level was calculated: (4 − albumin concentration in g/dL) × 0.8 + total serum calcium in mg/dL.ResultsA group of 1067 patients had a corrected calcium level of ≥10.5 mg/dL. The prevalence of hypercalcemia was 0.73% with total calcium and 1.09% with corrected calcium, respectively, with a 49% relative increase. Most patients (62%) had mild hypercalcemia (10.5-11.9 mg/dL); 3.7% had severe hypercalcemia (>14 mg/dL). With corrected calcium, the most common categories of hypercalcemia were malignancy (35.4%), hypercalcemia that was not further evaluated (31.1%), and hyperparathyroidism (22.4%). All patients in the unidentified category had albumin levels <2.8 g/dL. At the 1-year follow–up, 63% of the unidentified cases had normal calcium levels, and 26.8% had mild persistent hypercalcemia. Of those with persisting hypercalcemia at 1 year, 16.8% were diagnosed with hyperparathyroidism.ConclusionUsing albumin-corrected calcium resulted in an ∼50% increase in the detection of hypercalcemia cases. Although hypercalcemia resolved in majority of the undiagnosed cases at 1 year, a number of these remained abnormal. Detecting hypercalcemic disorders by correcting for low albumin level can help identify conditions such as hyperparathyroidism. Adding auto-calculated albumin-corrected calcium to routine laboratory tests could be a cost-effective intervention to improve the detection of hypercalcemic disorders.     

Congenital Craniopharyngioma and Hypercalcemia Induced by Parathyroid Hormone-Related Protein

ObjectiveTo report a case of congenital craniopharyngioma and parathyroid hormone-related protein (PTHrP)-associated humoral hypercalcemia.MethodsDetails of this unusual case are reviewed, from detection of fetal hydrocephalus and a brain tumor, through cesarean delivery at 36 weeks of gestation, to subsequent laboratory studies, management, and confirmation of the diagnosis.ResultsAlthough PTHrP has been well documented as a cause of humoral hypercalcemia of malignancy (HHM) in adult patients with cancer, HHM is uncommon in children. In addition, HHM has rarely been ascribed to nonmalignant tumors. To the best of our knowledge, we report the first case of a neonate with congenital craniopharyngioma and refractory hypercalcemia (peak ionized calcium level of 1.92 mmol/L; normal, 1.05 to 1.3) attributed to an elevated PTHrP value of 8.6 pmol/L (normal, less than 4.7). Intact parathyroid hormone was appropriately undetectable (less than 10 pg/mL; normal, 15 to 65). Despite calcitonin treatment, the hypercalcemia persisted. Although pamidronate infusion stabilized the serum calcium level, the baby did not survive.ConclusionThe diagnosis of craniopharyngioma was confirmed at autopsy, and immunohistochemical studies substantiated that the craniopharyngioma produced PTHrP. (Endocr Pract. 2007;13:67-71)     

Gigantic mammary hyperplasia in pregnancy associated with pseudohyperparathyroidism

This is the first report of hypercalcemia due to benign gigantic mammary hyperplasia in a pregnant women. Endocrinologic examinations did not disclose any known cause for the symptomatic hypercalcemia. Bilateral total mastectomy decreased the serum calcium level to normal. The case is presented with discussion and a literature review.     

Intraspecific chromosomal variability in human pathogenic fungi, especially in Histoplasma capsulatum

The ploidy, karyotype, and chromosome length polymorphism (CLP) of human pathogenic fungi were revised with emphasis on Histoplasma capsulatum, the causative agent of the systemic mycosis, histoplasmosis. Currently, different systems of gel electrophoresis are being used to determine fungal electrokaryotypes (EK). By renaturation kinetic and genomic reconstruction in H. capsulatum strains (G-186AS and Downs), estimated genome sizes of 23 and 32 Mb were determined for both strains, respectively. The haploid state was proposed for both strains, although aneuploidy was suggested for the Downs strain. Contour-clamped homogeneous electric field (CHEF), field inversion gel electrophoresis (FIGE), and Southern blot using different probes showed the presence of six to seven chromosomes in the Downs strain (low virulence), whereas four chromosomes were identified in the G-186B strain (high virulence). The use of these methods in the three major H. capsulatum reference strains (G-217B and Downs from the United States of America, G-186B from Panama) revealed distinct chromosome sizes, from 0.5 to 5.7 Mb, with CLP associated with chromosomes size and mobility. Recently, by CHEF, using 19 H. capsulatum isolates from Latin-America and the G-186B strain, five to seven chromosomes with 1.1 to 11.2 Mb molecular sizes were revealed, which again suggested CLP in H. capsulatum. However, to elucidate the EKs polymorphism in H. capsulatum and its relationship with the isolates phenotype more studies are needed to understand the mechanisms controlling ploidy variability.